diff options
Diffstat (limited to 'src/lib/crypt_ops')
53 files changed, 2490 insertions, 933 deletions
diff --git a/src/lib/crypt_ops/.may_include b/src/lib/crypt_ops/.may_include index a0fa4ec05c..810e777271 100644 --- a/src/lib/crypt_ops/.may_include +++ b/src/lib/crypt_ops/.may_include @@ -1,6 +1,7 @@ orconfig.h lib/arch/*.h lib/cc/*.h +lib/conf/*.h lib/container/*.h lib/crypt_ops/*.h lib/ctime/*.h @@ -12,13 +13,16 @@ lib/malloc/*.h lib/intmath/*.h lib/sandbox/*.h lib/string/*.h -lib/testsupport/testsupport.h +lib/subsys/*.h +lib/testsupport/*.h lib/thread/*.h lib/log/*.h +lib/crypt_ops/*.inc + trunnel/pwbox.h keccak-tiny/*.h ed25519/*.h -siphash.h +ext/siphash.h diff --git a/src/lib/crypt_ops/aes.h b/src/lib/crypt_ops/aes.h index 7c774062d9..c25417b4e6 100644 --- a/src/lib/crypt_ops/aes.h +++ b/src/lib/crypt_ops/aes.h @@ -1,6 +1,6 @@ /* Copyright (c) 2003, Roger Dingledine * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /* Implements a minimal interface to counter-mode AES. */ @@ -16,7 +16,7 @@ #include "lib/cc/torint.h" #include "lib/malloc/malloc.h" -typedef struct aes_cnt_cipher aes_cnt_cipher_t; +typedef struct aes_cnt_cipher_t aes_cnt_cipher_t; aes_cnt_cipher_t* aes_new_cipher(const uint8_t *key, const uint8_t *iv, int key_bits); diff --git a/src/lib/crypt_ops/aes_nss.c b/src/lib/crypt_ops/aes_nss.c index 4eda5e5902..71d2f01449 100644 --- a/src/lib/crypt_ops/aes_nss.c +++ b/src/lib/crypt_ops/aes_nss.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -15,10 +15,10 @@ #include "lib/crypt_ops/crypto_util.h" #include "lib/log/util_bug.h" -DISABLE_GCC_WARNING(strict-prototypes) +DISABLE_GCC_WARNING("-Wstrict-prototypes") #include <pk11pub.h> #include <secerr.h> -ENABLE_GCC_WARNING(strict-prototypes) +ENABLE_GCC_WARNING("-Wstrict-prototypes") aes_cnt_cipher_t * aes_new_cipher(const uint8_t *key, const uint8_t *iv, diff --git a/src/lib/crypt_ops/aes_openssl.c b/src/lib/crypt_ops/aes_openssl.c index 2f985d4512..502f7703bd 100644 --- a/src/lib/crypt_ops/aes_openssl.c +++ b/src/lib/crypt_ops/aes_openssl.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -28,7 +28,7 @@ #error "We require OpenSSL >= 1.0.0" #endif -DISABLE_GCC_WARNING(redundant-decls) +DISABLE_GCC_WARNING("-Wredundant-decls") #include <stdlib.h> #include <string.h> @@ -37,9 +37,8 @@ DISABLE_GCC_WARNING(redundant-decls) #include <openssl/engine.h> #include <openssl/modes.h> -ENABLE_GCC_WARNING(redundant-decls) +ENABLE_GCC_WARNING("-Wredundant-decls") -#include "lib/crypt_ops/aes.h" #include "lib/log/log.h" #include "lib/ctime/di_ops.h" @@ -148,13 +147,13 @@ evaluate_ctr_for_aes(void) { return 0; } -#else /* !(defined(USE_EVP_AES_CTR)) */ +#else /* !defined(USE_EVP_AES_CTR) */ /*======================================================================*/ /* Interface to AES code, and counter implementation */ /** Implements an AES counter-mode cipher. */ -struct aes_cnt_cipher { +struct aes_cnt_cipher_t { /** This next element (however it's defined) is the AES key. */ union { EVP_CIPHER_CTX evp; diff --git a/src/lib/crypt_ops/certs.md b/src/lib/crypt_ops/certs.md new file mode 100644 index 0000000000..f3bd8c2c96 --- /dev/null +++ b/src/lib/crypt_ops/certs.md @@ -0,0 +1,29 @@ + +@page certificates Certificates in Tor + +We have, alas, several certificate types in Tor. + +The tor_x509_cert_t type represents an X.509 certificate. This document +won't explain X.509 to you -- possibly, no document can. (OTOH, Peter +Gutmann's "x.509 style guide", though severely dated, does a good job of +explaining how awful x.509 can be.) Do not introduce any new usages of +X.509. Right now we only use it in places where TLS forces us to do so. +See x509.c for more information about using this type. + + +The authority_cert_t type is used only for directory authority keys. It +has a medium-term signing key (which the authorities actually keep +online) signed by a long-term identity key (which the authority operator +had really better be keeping offline). Don't use it for any new kind of +certificate. + +For new places where you need a certificate, consider tor_cert_t: it +represents a typed and dated _something_ signed by an Ed25519 key. The +format is described in tor-spec. Unlike x.509, you can write it on a +napkin. The torcert.c file is used for manipulating these certificates and +their associated keys. + +(Additionally, the Tor directory design uses a fairly wide variety of +documents that include keys and which are signed by keys. You can +consider these documents to be an additional kind of certificate if you +want.) diff --git a/src/lib/crypt_ops/compat_openssl.h b/src/lib/crypt_ops/compat_openssl.h index 6605d01045..c2e1459078 100644 --- a/src/lib/crypt_ops/compat_openssl.h +++ b/src/lib/crypt_ops/compat_openssl.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ #ifndef TOR_COMPAT_OPENSSL_H @@ -41,7 +41,7 @@ ((st) == SSL3_ST_SW_SRVR_HELLO_B)) #define OSSL_HANDSHAKE_STATE int #define CONST_IF_OPENSSL_1_1_API -#else /* !(!defined(OPENSSL_1_1_API)) */ +#else /* defined(OPENSSL_1_1_API) */ #define STATE_IS_SW_SERVER_HELLO(st) \ ((st) == TLS_ST_SW_SRVR_HELLO) #define CONST_IF_OPENSSL_1_1_API const diff --git a/src/lib/crypt_ops/crypto_cipher.c b/src/lib/crypt_ops/crypto_cipher.c index 7bc2edad54..0a24a580ae 100644 --- a/src/lib/crypt_ops/crypto_cipher.c +++ b/src/lib/crypt_ops/crypto_cipher.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_cipher.h b/src/lib/crypt_ops/crypto_cipher.h index cc4fbf7a41..1e22a7c138 100644 --- a/src/lib/crypt_ops/crypto_cipher.h +++ b/src/lib/crypt_ops/crypto_cipher.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -25,7 +25,7 @@ /** Length of our symmetric cipher's keys of 256-bit. */ #define CIPHER256_KEY_LEN 32 -typedef struct aes_cnt_cipher crypto_cipher_t; +typedef struct aes_cnt_cipher_t crypto_cipher_t; /* environment setup */ crypto_cipher_t *crypto_cipher_new(const char *key); @@ -54,4 +54,4 @@ int crypto_cipher_decrypt_with_iv(const char *key, char *to, size_t tolen, const char *from, size_t fromlen); -#endif /* !defined(TOR_CRYPTO_H) */ +#endif /* !defined(TOR_CRYPTO_CIPHER_H) */ diff --git a/src/lib/crypt_ops/crypto_curve25519.c b/src/lib/crypt_ops/crypto_curve25519.c index de4e17a296..2a2589f07d 100644 --- a/src/lib/crypt_ops/crypto_curve25519.c +++ b/src/lib/crypt_ops/crypto_curve25519.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2012-2019, The Tor Project, Inc. */ +/* Copyright (c) 2012-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_curve25519.h b/src/lib/crypt_ops/crypto_curve25519.h index 061a7a3505..154a0b94bc 100644 --- a/src/lib/crypt_ops/crypto_curve25519.h +++ b/src/lib/crypt_ops/crypto_curve25519.h @@ -1,4 +1,4 @@ -/* Copyright (c) 2012-2019, The Tor Project, Inc. */ +/* Copyright (c) 2012-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -76,8 +76,8 @@ STATIC int curve25519_basepoint_impl(uint8_t *output, const uint8_t *secret); int curve25519_public_from_base64(curve25519_public_key_t *pkey, const char *input); -int curve25519_public_to_base64(char *output, - const curve25519_public_key_t *pkey); +void curve25519_public_to_base64(char *output, + const curve25519_public_key_t *pkey); void curve25519_set_impl_params(int use_ed); void curve25519_init(void); diff --git a/src/lib/crypt_ops/crypto_dh.c b/src/lib/crypt_ops/crypto_dh.c index 4be7948761..086aceed6f 100644 --- a/src/lib/crypt_ops/crypto_dh.c +++ b/src/lib/crypt_ops/crypto_dh.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_dh.h b/src/lib/crypt_ops/crypto_dh.h index 850d50c7ae..2a0e1f6912 100644 --- a/src/lib/crypt_ops/crypto_dh.h +++ b/src/lib/crypt_ops/crypto_dh.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_dh_nss.c b/src/lib/crypt_ops/crypto_dh_nss.c index 379eb84a4f..018db8bf43 100644 --- a/src/lib/crypt_ops/crypto_dh_nss.c +++ b/src/lib/crypt_ops/crypto_dh_nss.c @@ -1,11 +1,11 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** - * \file crypto_dh_nss.h + * \file crypto_dh_nss.c * * \brief NSS implementation of Diffie-Hellman over Z_p. **/ diff --git a/src/lib/crypt_ops/crypto_dh_openssl.c b/src/lib/crypt_ops/crypto_dh_openssl.c index 8c6388fd5d..c5f7271596 100644 --- a/src/lib/crypt_ops/crypto_dh_openssl.c +++ b/src/lib/crypt_ops/crypto_dh_openssl.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -17,11 +17,11 @@ #include "lib/log/log.h" #include "lib/log/util_bug.h" -DISABLE_GCC_WARNING(redundant-decls) +DISABLE_GCC_WARNING("-Wredundant-decls") #include <openssl/dh.h> -ENABLE_GCC_WARNING(redundant-decls) +ENABLE_GCC_WARNING("-Wredundant-decls") #include <openssl/bn.h> #include <string.h> @@ -34,7 +34,7 @@ static int tor_check_dh_key(int severity, const BIGNUM *bn); struct crypto_dh_t { DH *dh; /**< The openssl DH object */ }; -#endif +#endif /* !defined(ENABLE_NSS) */ static DH *new_openssl_dh_from_params(BIGNUM *p, BIGNUM *g); @@ -68,7 +68,7 @@ crypto_validate_dh_params(const BIGNUM *p, const BIGNUM *g) goto out; if (!DH_set0_pqg(dh, dh_p, NULL, dh_g)) goto out; -#else /* !(defined(OPENSSL_1_1_API)) */ +#else /* !defined(OPENSSL_1_1_API) */ if (!(dh->p = BN_dup(p))) goto out; if (!(dh->g = BN_dup(g))) @@ -100,10 +100,10 @@ crypto_validate_dh_params(const BIGNUM *p, const BIGNUM *g) DH_free(dh); return ret; } -#endif +#endif /* 0 */ /** - * Helper: convert <b>hex<b> to a bignum, and return it. Assert that the + * Helper: convert <b>hex</b> to a bignum, and return it. Assert that the * operation was successful. */ static BIGNUM * @@ -202,7 +202,7 @@ crypto_dh_new(int dh_type) tor_free(res); // sets res to NULL. return res; } -#endif +#endif /* !defined(ENABLE_NSS) */ /** Create and return a new openssl DH from a given prime and generator. */ static DH * @@ -231,7 +231,7 @@ new_openssl_dh_from_params(BIGNUM *p, BIGNUM *g) if (!DH_set_length(res_dh, DH_PRIVATE_KEY_BITS)) goto err; -#else /* !(defined(OPENSSL_1_1_API)) */ +#else /* !defined(OPENSSL_1_1_API) */ res_dh->p = dh_p; res_dh->g = dh_g; res_dh->length = DH_PRIVATE_KEY_BITS; @@ -298,7 +298,7 @@ crypto_dh_generate_public(crypto_dh_t *dh) "the-universe chances really do happen. Treating as a failure."); return -1; } -#else /* !(defined(OPENSSL_1_1_API)) */ +#else /* !defined(OPENSSL_1_1_API) */ if (tor_check_dh_key(LOG_WARN, dh->dh->pub_key)<0) { /* LCOV_EXCL_START * If this happens, then openssl's DH implementation is busted. */ @@ -461,7 +461,7 @@ crypto_dh_free_(crypto_dh_t *dh) DH_free(dh->dh); tor_free(dh); } -#endif +#endif /* !defined(ENABLE_NSS) */ void crypto_dh_free_all_openssl(void) diff --git a/src/lib/crypt_ops/crypto_digest.c b/src/lib/crypt_ops/crypto_digest.c index de81b87b7e..7775e69410 100644 --- a/src/lib/crypt_ops/crypto_digest.c +++ b/src/lib/crypt_ops/crypto_digest.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -23,171 +23,6 @@ #include "lib/arch/bytes.h" -#ifdef ENABLE_NSS -DISABLE_GCC_WARNING(strict-prototypes) -#include <pk11pub.h> -ENABLE_GCC_WARNING(strict-prototypes) -#else - -#include "lib/crypt_ops/crypto_openssl_mgt.h" - -DISABLE_GCC_WARNING(redundant-decls) - -#include <openssl/hmac.h> -#include <openssl/sha.h> - -ENABLE_GCC_WARNING(redundant-decls) -#endif - -#ifdef ENABLE_NSS -/** - * Convert a digest_algorithm_t (used by tor) to a HashType (used by NSS). - * On failure, return SEC_OID_UNKNOWN. */ -static SECOidTag -digest_alg_to_nss_oid(digest_algorithm_t alg) -{ - switch (alg) { - case DIGEST_SHA1: return SEC_OID_SHA1; - case DIGEST_SHA256: return SEC_OID_SHA256; - case DIGEST_SHA512: return SEC_OID_SHA512; - case DIGEST_SHA3_256: FALLTHROUGH; - case DIGEST_SHA3_512: FALLTHROUGH; - default: - return SEC_OID_UNKNOWN; - } -} - -/* Helper: get an unkeyed digest via pk11wrap */ -static int -digest_nss_internal(SECOidTag alg, - char *digest, unsigned len_out, - const char *msg, size_t msg_len) -{ - if (alg == SEC_OID_UNKNOWN) - return -1; - tor_assert(msg_len <= UINT_MAX); - - int rv = -1; - SECStatus s; - PK11Context *ctx = PK11_CreateDigestContext(alg); - if (!ctx) - return -1; - - s = PK11_DigestBegin(ctx); - if (s != SECSuccess) - goto done; - - s = PK11_DigestOp(ctx, (const unsigned char *)msg, (unsigned int)msg_len); - if (s != SECSuccess) - goto done; - - unsigned int len = 0; - s = PK11_DigestFinal(ctx, (unsigned char *)digest, &len, len_out); - if (s != SECSuccess) - goto done; - - rv = 0; - done: - PK11_DestroyContext(ctx, PR_TRUE); - return rv; -} - -/** True iff alg is implemented in our crypto library, and we want to use that - * implementation */ -static bool -library_supports_digest(digest_algorithm_t alg) -{ - switch (alg) { - case DIGEST_SHA1: FALLTHROUGH; - case DIGEST_SHA256: FALLTHROUGH; - case DIGEST_SHA512: - return true; - case DIGEST_SHA3_256: FALLTHROUGH; - case DIGEST_SHA3_512: FALLTHROUGH; - default: - return false; - } -} -#endif - -/* Crypto digest functions */ - -/** Compute the SHA1 digest of the <b>len</b> bytes on data stored in - * <b>m</b>. Write the DIGEST_LEN byte result into <b>digest</b>. - * Return 0 on success, -1 on failure. - */ -MOCK_IMPL(int, -crypto_digest,(char *digest, const char *m, size_t len)) -{ - tor_assert(m); - tor_assert(digest); -#ifdef ENABLE_NSS - return digest_nss_internal(SEC_OID_SHA1, digest, DIGEST_LEN, m, len); -#else - if (SHA1((const unsigned char*)m,len,(unsigned char*)digest) == NULL) { - return -1; - } -#endif - return 0; -} - -/** Compute a 256-bit digest of <b>len</b> bytes in data stored in <b>m</b>, - * using the algorithm <b>algorithm</b>. Write the DIGEST_LEN256-byte result - * into <b>digest</b>. Return 0 on success, -1 on failure. */ -int -crypto_digest256(char *digest, const char *m, size_t len, - digest_algorithm_t algorithm) -{ - tor_assert(m); - tor_assert(digest); - tor_assert(algorithm == DIGEST_SHA256 || algorithm == DIGEST_SHA3_256); - - int ret = 0; - if (algorithm == DIGEST_SHA256) { -#ifdef ENABLE_NSS - return digest_nss_internal(SEC_OID_SHA256, digest, DIGEST256_LEN, m, len); -#else - ret = (SHA256((const uint8_t*)m,len,(uint8_t*)digest) != NULL); -#endif - } else { - ret = (sha3_256((uint8_t *)digest, DIGEST256_LEN,(const uint8_t *)m, len) - > -1); - } - - if (!ret) - return -1; - return 0; -} - -/** Compute a 512-bit digest of <b>len</b> bytes in data stored in <b>m</b>, - * using the algorithm <b>algorithm</b>. Write the DIGEST_LEN512-byte result - * into <b>digest</b>. Return 0 on success, -1 on failure. */ -int -crypto_digest512(char *digest, const char *m, size_t len, - digest_algorithm_t algorithm) -{ - tor_assert(m); - tor_assert(digest); - tor_assert(algorithm == DIGEST_SHA512 || algorithm == DIGEST_SHA3_512); - - int ret = 0; - if (algorithm == DIGEST_SHA512) { -#ifdef ENABLE_NSS - return digest_nss_internal(SEC_OID_SHA512, digest, DIGEST512_LEN, m, len); -#else - ret = (SHA512((const unsigned char*)m,len,(unsigned char*)digest) - != NULL); -#endif - } else { - ret = (sha3_512((uint8_t*)digest, DIGEST512_LEN, (const uint8_t*)m, len) - > -1); - } - - if (!ret) - return -1; - return 0; -} - /** Set the common_digests_t in <b>ds_out</b> to contain every digest on the * <b>len</b> bytes in <b>m</b> that we know how to compute. Return 0 on * success, -1 on failure. */ @@ -267,485 +102,6 @@ crypto_digest_algorithm_get_length(digest_algorithm_t alg) } } -/** Intermediate information about the digest of a stream of data. */ -struct crypto_digest_t { - digest_algorithm_t algorithm; /**< Which algorithm is in use? */ - /** State for the digest we're using. Only one member of the - * union is usable, depending on the value of <b>algorithm</b>. Note also - * that space for other members might not even be allocated! - */ - union { -#ifdef ENABLE_NSS - PK11Context *ctx; -#else - SHA_CTX sha1; /**< state for SHA1 */ - SHA256_CTX sha2; /**< state for SHA256 */ - SHA512_CTX sha512; /**< state for SHA512 */ -#endif - keccak_state sha3; /**< state for SHA3-[256,512] */ - } d; -}; - -#ifdef TOR_UNIT_TESTS - -digest_algorithm_t -crypto_digest_get_algorithm(crypto_digest_t *digest) -{ - tor_assert(digest); - - return digest->algorithm; -} - -#endif /* defined(TOR_UNIT_TESTS) */ - -/** - * Return the number of bytes we need to malloc in order to get a - * crypto_digest_t for <b>alg</b>, or the number of bytes we need to wipe - * when we free one. - */ -static size_t -crypto_digest_alloc_bytes(digest_algorithm_t alg) -{ - /* Helper: returns the number of bytes in the 'f' field of 'st' */ -#define STRUCT_FIELD_SIZE(st, f) (sizeof( ((st*)0)->f )) - /* Gives the length of crypto_digest_t through the end of the field 'd' */ -#define END_OF_FIELD(f) (offsetof(crypto_digest_t, f) + \ - STRUCT_FIELD_SIZE(crypto_digest_t, f)) - switch (alg) { -#ifdef ENABLE_NSS - case DIGEST_SHA1: FALLTHROUGH; - case DIGEST_SHA256: FALLTHROUGH; - case DIGEST_SHA512: - return END_OF_FIELD(d.ctx); -#else - case DIGEST_SHA1: - return END_OF_FIELD(d.sha1); - case DIGEST_SHA256: - return END_OF_FIELD(d.sha2); - case DIGEST_SHA512: - return END_OF_FIELD(d.sha512); -#endif - case DIGEST_SHA3_256: - case DIGEST_SHA3_512: - return END_OF_FIELD(d.sha3); - default: - tor_assert(0); // LCOV_EXCL_LINE - return 0; // LCOV_EXCL_LINE - } -#undef END_OF_FIELD -#undef STRUCT_FIELD_SIZE -} - -/** - * Internal function: create and return a new digest object for 'algorithm'. - * Does not typecheck the algorithm. - */ -static crypto_digest_t * -crypto_digest_new_internal(digest_algorithm_t algorithm) -{ - crypto_digest_t *r = tor_malloc(crypto_digest_alloc_bytes(algorithm)); - r->algorithm = algorithm; - - switch (algorithm) - { -#ifdef ENABLE_NSS - case DIGEST_SHA1: FALLTHROUGH; - case DIGEST_SHA256: FALLTHROUGH; - case DIGEST_SHA512: - r->d.ctx = PK11_CreateDigestContext(digest_alg_to_nss_oid(algorithm)); - if (BUG(!r->d.ctx)) { - tor_free(r); - return NULL; - } - if (BUG(SECSuccess != PK11_DigestBegin(r->d.ctx))) { - crypto_digest_free(r); - return NULL; - } - break; -#else - case DIGEST_SHA1: - SHA1_Init(&r->d.sha1); - break; - case DIGEST_SHA256: - SHA256_Init(&r->d.sha2); - break; - case DIGEST_SHA512: - SHA512_Init(&r->d.sha512); - break; -#endif - case DIGEST_SHA3_256: - keccak_digest_init(&r->d.sha3, 256); - break; - case DIGEST_SHA3_512: - keccak_digest_init(&r->d.sha3, 512); - break; - default: - tor_assert_unreached(); - } - - return r; -} - -/** Allocate and return a new digest object to compute SHA1 digests. - */ -crypto_digest_t * -crypto_digest_new(void) -{ - return crypto_digest_new_internal(DIGEST_SHA1); -} - -/** Allocate and return a new digest object to compute 256-bit digests - * using <b>algorithm</b>. - * - * C_RUST_COUPLED: `external::crypto_digest::crypto_digest256_new` - * C_RUST_COUPLED: `crypto::digest::Sha256::default` - */ -crypto_digest_t * -crypto_digest256_new(digest_algorithm_t algorithm) -{ - tor_assert(algorithm == DIGEST_SHA256 || algorithm == DIGEST_SHA3_256); - return crypto_digest_new_internal(algorithm); -} - -/** Allocate and return a new digest object to compute 512-bit digests - * using <b>algorithm</b>. */ -crypto_digest_t * -crypto_digest512_new(digest_algorithm_t algorithm) -{ - tor_assert(algorithm == DIGEST_SHA512 || algorithm == DIGEST_SHA3_512); - return crypto_digest_new_internal(algorithm); -} - -/** Deallocate a digest object. - */ -void -crypto_digest_free_(crypto_digest_t *digest) -{ - if (!digest) - return; -#ifdef ENABLE_NSS - if (library_supports_digest(digest->algorithm)) { - PK11_DestroyContext(digest->d.ctx, PR_TRUE); - } -#endif - size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); - memwipe(digest, 0, bytes); - tor_free(digest); -} - -/** Add <b>len</b> bytes from <b>data</b> to the digest object. - * - * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_add_bytess` - * C_RUST_COUPLED: `crypto::digest::Sha256::process` - */ -void -crypto_digest_add_bytes(crypto_digest_t *digest, const char *data, - size_t len) -{ - tor_assert(digest); - tor_assert(data); - /* Using the SHA*_*() calls directly means we don't support doing - * SHA in hardware. But so far the delay of getting the question - * to the hardware, and hearing the answer, is likely higher than - * just doing it ourselves. Hashes are fast. - */ - switch (digest->algorithm) { -#ifdef ENABLE_NSS - case DIGEST_SHA1: FALLTHROUGH; - case DIGEST_SHA256: FALLTHROUGH; - case DIGEST_SHA512: - tor_assert(len <= UINT_MAX); - SECStatus s = PK11_DigestOp(digest->d.ctx, - (const unsigned char *)data, - (unsigned int)len); - tor_assert(s == SECSuccess); - break; -#else - case DIGEST_SHA1: - SHA1_Update(&digest->d.sha1, (void*)data, len); - break; - case DIGEST_SHA256: - SHA256_Update(&digest->d.sha2, (void*)data, len); - break; - case DIGEST_SHA512: - SHA512_Update(&digest->d.sha512, (void*)data, len); - break; -#endif - case DIGEST_SHA3_256: FALLTHROUGH; - case DIGEST_SHA3_512: - keccak_digest_update(&digest->d.sha3, (const uint8_t *)data, len); - break; - default: - /* LCOV_EXCL_START */ - tor_fragile_assert(); - break; - /* LCOV_EXCL_STOP */ - } -} - -/** Compute the hash of the data that has been passed to the digest - * object; write the first out_len bytes of the result to <b>out</b>. - * <b>out_len</b> must be \<= DIGEST512_LEN. - * - * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_get_digest` - * C_RUST_COUPLED: `impl digest::FixedOutput for Sha256` - */ -void -crypto_digest_get_digest(crypto_digest_t *digest, - char *out, size_t out_len) -{ - unsigned char r[DIGEST512_LEN]; - tor_assert(digest); - tor_assert(out); - tor_assert(out_len <= crypto_digest_algorithm_get_length(digest->algorithm)); - - /* The SHA-3 code handles copying into a temporary ctx, and also can handle - * short output buffers by truncating appropriately. */ - if (digest->algorithm == DIGEST_SHA3_256 || - digest->algorithm == DIGEST_SHA3_512) { - keccak_digest_sum(&digest->d.sha3, (uint8_t *)out, out_len); - return; - } - -#ifdef ENABLE_NSS - /* Copy into a temporary buffer since DigestFinal (alters) the context */ - unsigned char buf[1024]; - unsigned int saved_len = 0; - unsigned rlen; - unsigned char *saved = PK11_SaveContextAlloc(digest->d.ctx, - buf, sizeof(buf), - &saved_len); - tor_assert(saved); - SECStatus s = PK11_DigestFinal(digest->d.ctx, r, &rlen, sizeof(r)); - tor_assert(s == SECSuccess); - tor_assert(rlen >= out_len); - s = PK11_RestoreContext(digest->d.ctx, saved, saved_len); - tor_assert(s == SECSuccess); - if (saved != buf) { - PORT_ZFree(saved, saved_len); - } -#else - const size_t alloc_bytes = crypto_digest_alloc_bytes(digest->algorithm); - crypto_digest_t tmpenv; - /* memcpy into a temporary ctx, since SHA*_Final clears the context */ - memcpy(&tmpenv, digest, alloc_bytes); - switch (digest->algorithm) { - case DIGEST_SHA1: - SHA1_Final(r, &tmpenv.d.sha1); - break; - case DIGEST_SHA256: - SHA256_Final(r, &tmpenv.d.sha2); - break; - case DIGEST_SHA512: - SHA512_Final(r, &tmpenv.d.sha512); - break; -//LCOV_EXCL_START - case DIGEST_SHA3_256: FALLTHROUGH; - case DIGEST_SHA3_512: - default: - log_warn(LD_BUG, "Handling unexpected algorithm %d", digest->algorithm); - /* This is fatal, because it should never happen. */ - tor_assert_unreached(); - break; -//LCOV_EXCL_STOP - } -#endif - memcpy(out, r, out_len); - memwipe(r, 0, sizeof(r)); -} - -/** Allocate and return a new digest object with the same state as - * <b>digest</b> - * - * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_dup` - * C_RUST_COUPLED: `impl Clone for crypto::digest::Sha256` - */ -crypto_digest_t * -crypto_digest_dup(const crypto_digest_t *digest) -{ - tor_assert(digest); - const size_t alloc_bytes = crypto_digest_alloc_bytes(digest->algorithm); - crypto_digest_t *result = tor_memdup(digest, alloc_bytes); -#ifdef ENABLE_NSS - if (library_supports_digest(digest->algorithm)) { - result->d.ctx = PK11_CloneContext(digest->d.ctx); - } -#endif - return result; -} - -/** Temporarily save the state of <b>digest</b> in <b>checkpoint</b>. - * Asserts that <b>digest</b> is a SHA1 digest object. - */ -void -crypto_digest_checkpoint(crypto_digest_checkpoint_t *checkpoint, - const crypto_digest_t *digest) -{ - const size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); - tor_assert(bytes <= sizeof(checkpoint->mem)); -#ifdef ENABLE_NSS - if (library_supports_digest(digest->algorithm)) { - unsigned char *allocated; - allocated = PK11_SaveContextAlloc(digest->d.ctx, - (unsigned char *)checkpoint->mem, - sizeof(checkpoint->mem), - &checkpoint->bytes_used); - /* No allocation is allowed here. */ - tor_assert(allocated == checkpoint->mem); - return; - } -#endif - memcpy(checkpoint->mem, digest, bytes); -} - -/** Restore the state of <b>digest</b> from <b>checkpoint</b>. - * Asserts that <b>digest</b> is a SHA1 digest object. Requires that the - * state was previously stored with crypto_digest_checkpoint() */ -void -crypto_digest_restore(crypto_digest_t *digest, - const crypto_digest_checkpoint_t *checkpoint) -{ - const size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); -#ifdef ENABLE_NSS - if (library_supports_digest(digest->algorithm)) { - SECStatus s = PK11_RestoreContext(digest->d.ctx, - (unsigned char *)checkpoint->mem, - checkpoint->bytes_used); - tor_assert(s == SECSuccess); - return; - } -#endif - memcpy(digest, checkpoint->mem, bytes); -} - -/** Replace the state of the digest object <b>into</b> with the state - * of the digest object <b>from</b>. Requires that 'into' and 'from' - * have the same digest type. - */ -void -crypto_digest_assign(crypto_digest_t *into, - const crypto_digest_t *from) -{ - tor_assert(into); - tor_assert(from); - tor_assert(into->algorithm == from->algorithm); - const size_t alloc_bytes = crypto_digest_alloc_bytes(from->algorithm); -#ifdef ENABLE_NSS - if (library_supports_digest(from->algorithm)) { - PK11_DestroyContext(into->d.ctx, PR_TRUE); - into->d.ctx = PK11_CloneContext(from->d.ctx); - return; - } -#endif - memcpy(into,from,alloc_bytes); -} - -/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest - * at <b>digest_out</b> to the hash of the concatenation of those strings, - * plus the optional string <b>append</b>, computed with the algorithm - * <b>alg</b>. - * <b>out_len</b> must be \<= DIGEST512_LEN. */ -void -crypto_digest_smartlist(char *digest_out, size_t len_out, - const smartlist_t *lst, - const char *append, - digest_algorithm_t alg) -{ - crypto_digest_smartlist_prefix(digest_out, len_out, NULL, lst, append, alg); -} - -/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest - * at <b>digest_out</b> to the hash of the concatenation of: the - * optional string <b>prepend</b>, those strings, - * and the optional string <b>append</b>, computed with the algorithm - * <b>alg</b>. - * <b>len_out</b> must be \<= DIGEST512_LEN. */ -void -crypto_digest_smartlist_prefix(char *digest_out, size_t len_out, - const char *prepend, - const smartlist_t *lst, - const char *append, - digest_algorithm_t alg) -{ - crypto_digest_t *d = crypto_digest_new_internal(alg); - if (prepend) - crypto_digest_add_bytes(d, prepend, strlen(prepend)); - SMARTLIST_FOREACH(lst, const char *, cp, - crypto_digest_add_bytes(d, cp, strlen(cp))); - if (append) - crypto_digest_add_bytes(d, append, strlen(append)); - crypto_digest_get_digest(d, digest_out, len_out); - crypto_digest_free(d); -} - -/** Compute the HMAC-SHA-256 of the <b>msg_len</b> bytes in <b>msg</b>, using - * the <b>key</b> of length <b>key_len</b>. Store the DIGEST256_LEN-byte - * result in <b>hmac_out</b>. Asserts on failure. - */ -void -crypto_hmac_sha256(char *hmac_out, - const char *key, size_t key_len, - const char *msg, size_t msg_len) -{ - /* If we've got OpenSSL >=0.9.8 we can use its hmac implementation. */ - tor_assert(key_len < INT_MAX); - tor_assert(msg_len < INT_MAX); - tor_assert(hmac_out); -#ifdef ENABLE_NSS - PK11SlotInfo *slot = NULL; - PK11SymKey *symKey = NULL; - PK11Context *hmac = NULL; - - int ok = 0; - SECStatus s; - SECItem keyItem, paramItem; - keyItem.data = (unsigned char *)key; - keyItem.len = (unsigned)key_len; - paramItem.type = siBuffer; - paramItem.data = NULL; - paramItem.len = 0; - - slot = PK11_GetBestSlot(CKM_SHA256_HMAC, NULL); - if (!slot) - goto done; - symKey = PK11_ImportSymKey(slot, CKM_SHA256_HMAC, - PK11_OriginUnwrap, CKA_SIGN, &keyItem, NULL); - if (!symKey) - goto done; - - hmac = PK11_CreateContextBySymKey(CKM_SHA256_HMAC, CKA_SIGN, symKey, - ¶mItem); - if (!hmac) - goto done; - s = PK11_DigestBegin(hmac); - if (s != SECSuccess) - goto done; - s = PK11_DigestOp(hmac, (const unsigned char *)msg, (unsigned int)msg_len); - if (s != SECSuccess) - goto done; - unsigned int len=0; - s = PK11_DigestFinal(hmac, (unsigned char *)hmac_out, &len, DIGEST256_LEN); - if (s != SECSuccess || len != DIGEST256_LEN) - goto done; - ok = 1; - - done: - if (hmac) - PK11_DestroyContext(hmac, PR_TRUE); - if (symKey) - PK11_FreeSymKey(symKey); - if (slot) - PK11_FreeSlot(slot); - - tor_assert(ok); -#else - unsigned char *rv = NULL; - rv = HMAC(EVP_sha256(), key, (int)key_len, (unsigned char*)msg, (int)msg_len, - (unsigned char*)hmac_out, NULL); - tor_assert(rv); -#endif -} - /** Compute a MAC using SHA3-256 of <b>msg_len</b> bytes in <b>msg</b> using a * <b>key</b> of length <b>key_len</b> and a <b>salt</b> of length * <b>salt_len</b>. Store the result of <b>len_out</b> bytes in in @@ -779,7 +135,26 @@ crypto_mac_sha3_256(uint8_t *mac_out, size_t len_out, /** Internal state for a eXtendable-Output Function (XOF). */ struct crypto_xof_t { +#ifdef OPENSSL_HAS_SHAKE3_EVP + /* XXXX We can't enable this yet, because OpenSSL's + * DigestFinalXOF function can't be called repeatedly on the same + * XOF. + * + * We could in theory use the undocumented SHA3_absorb and SHA3_squeeze + * functions, but let's not mess with undocumented OpenSSL internals any + * more than we have to. + * + * We could also revise our XOF code so that it only allows a single + * squeeze operation; we don't require streaming squeeze operations + * outside the tests yet. + */ + EVP_MD_CTX *ctx; +#else /* !defined(OPENSSL_HAS_SHAKE3_EVP) */ + /** + * State of the Keccak sponge for the SHAKE-256 computation. + **/ keccak_state s; +#endif /* defined(OPENSSL_HAS_SHAKE3_EVP) */ }; /** Allocate a new XOF object backed by SHAKE-256. The security level @@ -792,7 +167,14 @@ crypto_xof_new(void) { crypto_xof_t *xof; xof = tor_malloc(sizeof(crypto_xof_t)); +#ifdef OPENSSL_HAS_SHAKE256 + xof->ctx = EVP_MD_CTX_new(); + tor_assert(xof->ctx); + int r = EVP_DigestInit(xof->ctx, EVP_shake256()); + tor_assert(r == 1); +#else /* !defined(OPENSSL_HAS_SHAKE256) */ keccak_xof_init(&xof->s, 256); +#endif /* defined(OPENSSL_HAS_SHAKE256) */ return xof; } @@ -803,8 +185,13 @@ crypto_xof_new(void) void crypto_xof_add_bytes(crypto_xof_t *xof, const uint8_t *data, size_t len) { +#ifdef OPENSSL_HAS_SHAKE256 + int r = EVP_DigestUpdate(xof->ctx, data, len); + tor_assert(r == 1); +#else int i = keccak_xof_absorb(&xof->s, data, len); tor_assert(i == 0); +#endif /* defined(OPENSSL_HAS_SHAKE256) */ } /** Squeeze bytes out of a XOF object. Calling this routine will render @@ -813,8 +200,13 @@ crypto_xof_add_bytes(crypto_xof_t *xof, const uint8_t *data, size_t len) void crypto_xof_squeeze_bytes(crypto_xof_t *xof, uint8_t *out, size_t len) { +#ifdef OPENSSL_HAS_SHAKE256 + int r = EVP_DigestFinalXOF(xof->ctx, out, len); + tor_assert(r == 1); +#else int i = keccak_xof_squeeze(&xof->s, out, len); tor_assert(i == 0); +#endif /* defined(OPENSSL_HAS_SHAKE256) */ } /** Cleanse and deallocate a XOF object. */ @@ -823,6 +215,34 @@ crypto_xof_free_(crypto_xof_t *xof) { if (!xof) return; +#ifdef OPENSSL_HAS_SHAKE256 + if (xof->ctx) + EVP_MD_CTX_free(xof->ctx); +#endif memwipe(xof, 0, sizeof(crypto_xof_t)); tor_free(xof); } + +/** Compute the XOF (SHAKE256) of a <b>input_len</b> bytes at <b>input</b>, + * putting <b>output_len</b> bytes at <b>output</b>. */ +void +crypto_xof(uint8_t *output, size_t output_len, + const uint8_t *input, size_t input_len) +{ +#ifdef OPENSSL_HAS_SHA3 + EVP_MD_CTX *ctx = EVP_MD_CTX_new(); + tor_assert(ctx); + int r = EVP_DigestInit(ctx, EVP_shake256()); + tor_assert(r == 1); + r = EVP_DigestUpdate(ctx, input, input_len); + tor_assert(r == 1); + r = EVP_DigestFinalXOF(ctx, output, output_len); + tor_assert(r == 1); + EVP_MD_CTX_free(ctx); +#else /* !defined(OPENSSL_HAS_SHA3) */ + crypto_xof_t *xof = crypto_xof_new(); + crypto_xof_add_bytes(xof, input, input_len); + crypto_xof_squeeze_bytes(xof, output, output_len); + crypto_xof_free(xof); +#endif /* defined(OPENSSL_HAS_SHA3) */ +} diff --git a/src/lib/crypt_ops/crypto_digest.h b/src/lib/crypt_ops/crypto_digest.h index 47e60ce617..eefd2e3f0a 100644 --- a/src/lib/crypt_ops/crypto_digest.h +++ b/src/lib/crypt_ops/crypto_digest.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -38,6 +38,9 @@ /** Length of hex encoding of SHA512 digest, not including final NUL. */ #define HEX_DIGEST512_LEN 128 +/** + * An identifier for a cryptographic digest algorithm. + **/ typedef enum { DIGEST_SHA1 = 0, DIGEST_SHA256 = 1, @@ -45,16 +48,31 @@ typedef enum { DIGEST_SHA3_256 = 3, DIGEST_SHA3_512 = 4, } digest_algorithm_t; +/** Number of digest algorithms that we know */ #define N_DIGEST_ALGORITHMS (DIGEST_SHA3_512+1) +/** Number of digest algorithms to compute when computing "all the + * commonly used digests." + * + * (This is used in common_digests_t and related functions.) + */ #define N_COMMON_DIGEST_ALGORITHMS (DIGEST_SHA256+1) +/** + * Bytes of storage needed to record the state of an in-progress SHA-1 digest. + * + * This is a deliberate overestimate. + **/ #define DIGEST_CHECKPOINT_BYTES (SIZEOF_VOID_P + 512) + /** Structure used to temporarily save the a digest object. Only implemented * for SHA1 digest for now. */ typedef struct crypto_digest_checkpoint_t { #ifdef ENABLE_NSS + /** The number of bytes used in <b>mem</b>. */ unsigned int bytes_used; #endif + /** A buffer to store the SHA1 state. Its contents are unspecified, and + * are managed by the underlying crypto library.*/ uint8_t mem[DIGEST_CHECKPOINT_BYTES]; } crypto_digest_checkpoint_t; @@ -67,10 +85,19 @@ typedef struct crypto_digest_checkpoint_t { * once. **/ typedef struct { + /** An array of digest outputs, one for each "common" digest algorithm. */ char d[N_COMMON_DIGEST_ALGORITHMS][DIGEST256_LEN]; } common_digests_t; +/** + * State for computing a digest over a stream of data. + **/ typedef struct crypto_digest_t crypto_digest_t; + +/** + * State for computing an "extendable-output function" (like SHAKE) over a + * stream of data, and/or streaming the output. + **/ typedef struct crypto_xof_t crypto_xof_t; struct smartlist_t; @@ -97,6 +124,9 @@ crypto_digest_t *crypto_digest_new(void); crypto_digest_t *crypto_digest256_new(digest_algorithm_t algorithm); crypto_digest_t *crypto_digest512_new(digest_algorithm_t algorithm); void crypto_digest_free_(crypto_digest_t *digest); +/** + * Release all storage held in <b>d</b>, and set it to NULL. + **/ #define crypto_digest_free(d) \ FREE_AND_NULL(crypto_digest_t, crypto_digest_free_, (d)) void crypto_digest_add_bytes(crypto_digest_t *digest, const char *data, @@ -122,8 +152,13 @@ crypto_xof_t *crypto_xof_new(void); void crypto_xof_add_bytes(crypto_xof_t *xof, const uint8_t *data, size_t len); void crypto_xof_squeeze_bytes(crypto_xof_t *xof, uint8_t *out, size_t len); void crypto_xof_free_(crypto_xof_t *xof); +/** + * Release all storage held in <b>xof</b>, and set it to NULL. + **/ #define crypto_xof_free(xof) \ FREE_AND_NULL(crypto_xof_t, crypto_xof_free_, (xof)) +void crypto_xof(uint8_t *output, size_t output_len, + const uint8_t *input, size_t input_len); #ifdef TOR_UNIT_TESTS digest_algorithm_t crypto_digest_get_algorithm(crypto_digest_t *digest); diff --git a/src/lib/crypt_ops/crypto_digest_nss.c b/src/lib/crypt_ops/crypto_digest_nss.c new file mode 100644 index 0000000000..92c20fe9e8 --- /dev/null +++ b/src/lib/crypt_ops/crypto_digest_nss.c @@ -0,0 +1,563 @@ +/* Copyright (c) 2001, Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file crypto_digest_nss.c + * \brief Block of functions related with digest and xof utilities and + * operations (NSS specific implementations). + **/ + +#include "lib/container/smartlist.h" +#include "lib/crypt_ops/crypto_digest.h" +#include "lib/crypt_ops/crypto_util.h" +#include "lib/log/log.h" +#include "lib/log/util_bug.h" + +#include "keccak-tiny/keccak-tiny.h" + +#include <stdlib.h> +#include <string.h> + +#include "lib/arch/bytes.h" + +DISABLE_GCC_WARNING("-Wstrict-prototypes") +#include <pk11pub.h> +ENABLE_GCC_WARNING("-Wstrict-prototypes") + +/** + * Convert a digest_algorithm_t (used by tor) to a HashType (used by NSS). + * On failure, return SEC_OID_UNKNOWN. */ +static SECOidTag +digest_alg_to_nss_oid(digest_algorithm_t alg) +{ + switch (alg) { + case DIGEST_SHA1: return SEC_OID_SHA1; + case DIGEST_SHA256: return SEC_OID_SHA256; + case DIGEST_SHA512: return SEC_OID_SHA512; + case DIGEST_SHA3_256: FALLTHROUGH; + case DIGEST_SHA3_512: FALLTHROUGH; + default: + return SEC_OID_UNKNOWN; + } +} + +/** Helper: Compute an unkeyed digest of the <b>msg_len</b> bytes at + * <b>msg</b>, using the digest algorithm specified by <b>alg</b>. + * Store the result in the <b>len_out</b>-byte buffer at <b>digest</b>. + * Return the number of bytes written on success, and -1 on failure. + **/ +static int +digest_nss_internal(SECOidTag alg, + char *digest, unsigned len_out, + const char *msg, size_t msg_len) +{ + if (alg == SEC_OID_UNKNOWN) + return -1; + tor_assert(msg_len <= UINT_MAX); + + int rv = -1; + SECStatus s; + PK11Context *ctx = PK11_CreateDigestContext(alg); + if (!ctx) + return -1; + + s = PK11_DigestBegin(ctx); + if (s != SECSuccess) + goto done; + + s = PK11_DigestOp(ctx, (const unsigned char *)msg, (unsigned int)msg_len); + if (s != SECSuccess) + goto done; + + unsigned int len = 0; + s = PK11_DigestFinal(ctx, (unsigned char *)digest, &len, len_out); + if (s != SECSuccess) + goto done; + + rv = 0; + done: + PK11_DestroyContext(ctx, PR_TRUE); + return rv; +} + +/** True iff alg is implemented in our crypto library, and we want to use that + * implementation */ +static bool +library_supports_digest(digest_algorithm_t alg) +{ + switch (alg) { + case DIGEST_SHA1: FALLTHROUGH; + case DIGEST_SHA256: FALLTHROUGH; + case DIGEST_SHA512: + return true; + case DIGEST_SHA3_256: FALLTHROUGH; + case DIGEST_SHA3_512: FALLTHROUGH; + default: + return false; + } +} + +/* Crypto digest functions */ + +/** Compute the SHA1 digest of the <b>len</b> bytes on data stored in + * <b>m</b>. Write the DIGEST_LEN byte result into <b>digest</b>. + * Return 0 on success, -1 on failure. + */ +MOCK_IMPL(int, +crypto_digest,(char *digest, const char *m, size_t len)) +{ + tor_assert(m); + tor_assert(digest); + return digest_nss_internal(SEC_OID_SHA1, digest, DIGEST_LEN, m, len); +} + +/** Compute a 256-bit digest of <b>len</b> bytes in data stored in <b>m</b>, + * using the algorithm <b>algorithm</b>. Write the DIGEST_LEN256-byte result + * into <b>digest</b>. Return 0 on success, -1 on failure. */ +int +crypto_digest256(char *digest, const char *m, size_t len, + digest_algorithm_t algorithm) +{ + tor_assert(m); + tor_assert(digest); + tor_assert(algorithm == DIGEST_SHA256 || algorithm == DIGEST_SHA3_256); + + int ret = 0; + if (algorithm == DIGEST_SHA256) { + return digest_nss_internal(SEC_OID_SHA256, digest, DIGEST256_LEN, m, len); + } else { + ret = (sha3_256((uint8_t *)digest, DIGEST256_LEN,(const uint8_t *)m, len) + > -1); + } + + if (!ret) + return -1; + return 0; +} + +/** Compute a 512-bit digest of <b>len</b> bytes in data stored in <b>m</b>, + * using the algorithm <b>algorithm</b>. Write the DIGEST_LEN512-byte result + * into <b>digest</b>. Return 0 on success, -1 on failure. */ +int +crypto_digest512(char *digest, const char *m, size_t len, + digest_algorithm_t algorithm) +{ + tor_assert(m); + tor_assert(digest); + tor_assert(algorithm == DIGEST_SHA512 || algorithm == DIGEST_SHA3_512); + + int ret = 0; + if (algorithm == DIGEST_SHA512) { + return digest_nss_internal(SEC_OID_SHA512, digest, DIGEST512_LEN, m, len); + } else { + ret = (sha3_512((uint8_t*)digest, DIGEST512_LEN, (const uint8_t*)m, len) + > -1); + } + + if (!ret) + return -1; + return 0; +} + +/** Intermediate information about the digest of a stream of data. */ +struct crypto_digest_t { + digest_algorithm_t algorithm; /**< Which algorithm is in use? */ + /** State for the digest we're using. Only one member of the + * union is usable, depending on the value of <b>algorithm</b>. Note also + * that space for other members might not even be allocated! + */ + union { + PK11Context *ctx; + keccak_state sha3; /**< state for SHA3-[256,512] */ + } d; +}; + +#ifdef TOR_UNIT_TESTS + +digest_algorithm_t +crypto_digest_get_algorithm(crypto_digest_t *digest) +{ + tor_assert(digest); + + return digest->algorithm; +} + +#endif /* defined(TOR_UNIT_TESTS) */ + +/** + * Return the number of bytes we need to malloc in order to get a + * crypto_digest_t for <b>alg</b>, or the number of bytes we need to wipe + * when we free one. + */ +static size_t +crypto_digest_alloc_bytes(digest_algorithm_t alg) +{ + /* Helper: returns the number of bytes in the 'f' field of 'st' */ +#define STRUCT_FIELD_SIZE(st, f) (sizeof( ((st*)0)->f )) + /* Gives the length of crypto_digest_t through the end of the field 'd' */ +#define END_OF_FIELD(f) (offsetof(crypto_digest_t, f) + \ + STRUCT_FIELD_SIZE(crypto_digest_t, f)) + switch (alg) { + case DIGEST_SHA1: FALLTHROUGH; + case DIGEST_SHA256: FALLTHROUGH; + case DIGEST_SHA512: + return END_OF_FIELD(d.ctx); + case DIGEST_SHA3_256: + case DIGEST_SHA3_512: + return END_OF_FIELD(d.sha3); + default: + tor_assert(0); // LCOV_EXCL_LINE + return 0; // LCOV_EXCL_LINE + } +#undef END_OF_FIELD +#undef STRUCT_FIELD_SIZE +} + +/** + * Internal function: create and return a new digest object for 'algorithm'. + * Does not typecheck the algorithm. + */ +static crypto_digest_t * +crypto_digest_new_internal(digest_algorithm_t algorithm) +{ + crypto_digest_t *r = tor_malloc(crypto_digest_alloc_bytes(algorithm)); + r->algorithm = algorithm; + + switch (algorithm) + { + case DIGEST_SHA1: FALLTHROUGH; + case DIGEST_SHA256: FALLTHROUGH; + case DIGEST_SHA512: + r->d.ctx = PK11_CreateDigestContext(digest_alg_to_nss_oid(algorithm)); + if (BUG(!r->d.ctx)) { + tor_free(r); + return NULL; + } + if (BUG(SECSuccess != PK11_DigestBegin(r->d.ctx))) { + crypto_digest_free(r); + return NULL; + } + break; + case DIGEST_SHA3_256: + keccak_digest_init(&r->d.sha3, 256); + break; + case DIGEST_SHA3_512: + keccak_digest_init(&r->d.sha3, 512); + break; + default: + tor_assert_unreached(); + } + + return r; +} + +/** Allocate and return a new digest object to compute SHA1 digests. + */ +crypto_digest_t * +crypto_digest_new(void) +{ + return crypto_digest_new_internal(DIGEST_SHA1); +} + +/** Allocate and return a new digest object to compute 256-bit digests + * using <b>algorithm</b>. + * + * C_RUST_COUPLED: `external::crypto_digest::crypto_digest256_new` + * C_RUST_COUPLED: `crypto::digest::Sha256::default` + */ +crypto_digest_t * +crypto_digest256_new(digest_algorithm_t algorithm) +{ + tor_assert(algorithm == DIGEST_SHA256 || algorithm == DIGEST_SHA3_256); + return crypto_digest_new_internal(algorithm); +} + +/** Allocate and return a new digest object to compute 512-bit digests + * using <b>algorithm</b>. */ +crypto_digest_t * +crypto_digest512_new(digest_algorithm_t algorithm) +{ + tor_assert(algorithm == DIGEST_SHA512 || algorithm == DIGEST_SHA3_512); + return crypto_digest_new_internal(algorithm); +} + +/** Deallocate a digest object. + */ +void +crypto_digest_free_(crypto_digest_t *digest) +{ + if (!digest) + return; + if (library_supports_digest(digest->algorithm)) { + PK11_DestroyContext(digest->d.ctx, PR_TRUE); + } + size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); + memwipe(digest, 0, bytes); + tor_free(digest); +} + +/** Add <b>len</b> bytes from <b>data</b> to the digest object. + * + * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_add_bytess` + * C_RUST_COUPLED: `crypto::digest::Sha256::process` + */ +void +crypto_digest_add_bytes(crypto_digest_t *digest, const char *data, + size_t len) +{ + tor_assert(digest); + tor_assert(data); + /* Using the SHA*_*() calls directly means we don't support doing + * SHA in hardware. But so far the delay of getting the question + * to the hardware, and hearing the answer, is likely higher than + * just doing it ourselves. Hashes are fast. + */ + switch (digest->algorithm) { + case DIGEST_SHA1: FALLTHROUGH; + case DIGEST_SHA256: FALLTHROUGH; + case DIGEST_SHA512: + tor_assert(len <= UINT_MAX); + SECStatus s = PK11_DigestOp(digest->d.ctx, + (const unsigned char *)data, + (unsigned int)len); + tor_assert(s == SECSuccess); + break; + case DIGEST_SHA3_256: FALLTHROUGH; + case DIGEST_SHA3_512: + keccak_digest_update(&digest->d.sha3, (const uint8_t *)data, len); + break; + default: + /* LCOV_EXCL_START */ + tor_fragile_assert(); + break; + /* LCOV_EXCL_STOP */ + } +} + +/** Compute the hash of the data that has been passed to the digest + * object; write the first out_len bytes of the result to <b>out</b>. + * <b>out_len</b> must be \<= DIGEST512_LEN. + * + * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_get_digest` + * C_RUST_COUPLED: `impl digest::FixedOutput for Sha256` + */ +void +crypto_digest_get_digest(crypto_digest_t *digest, + char *out, size_t out_len) +{ + unsigned char r[DIGEST512_LEN]; + tor_assert(digest); + tor_assert(out); + tor_assert(out_len <= crypto_digest_algorithm_get_length(digest->algorithm)); + + /* The SHA-3 code handles copying into a temporary ctx, and also can handle + * short output buffers by truncating appropriately. */ + if (digest->algorithm == DIGEST_SHA3_256 || + digest->algorithm == DIGEST_SHA3_512) { + keccak_digest_sum(&digest->d.sha3, (uint8_t *)out, out_len); + return; + } + + /* Copy into a temporary buffer since DigestFinal (alters) the context */ + unsigned char buf[1024]; + unsigned int saved_len = 0; + unsigned rlen; + unsigned char *saved = PK11_SaveContextAlloc(digest->d.ctx, + buf, sizeof(buf), + &saved_len); + tor_assert(saved); + SECStatus s = PK11_DigestFinal(digest->d.ctx, r, &rlen, sizeof(r)); + tor_assert(s == SECSuccess); + tor_assert(rlen >= out_len); + s = PK11_RestoreContext(digest->d.ctx, saved, saved_len); + tor_assert(s == SECSuccess); + + if (saved != buf) { + PORT_ZFree(saved, saved_len); + } + memcpy(out, r, out_len); + memwipe(r, 0, sizeof(r)); +} + +/** Allocate and return a new digest object with the same state as + * <b>digest</b> + * + * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_dup` + * C_RUST_COUPLED: `impl Clone for crypto::digest::Sha256` + */ +crypto_digest_t * +crypto_digest_dup(const crypto_digest_t *digest) +{ + tor_assert(digest); + const size_t alloc_bytes = crypto_digest_alloc_bytes(digest->algorithm); + crypto_digest_t *result = tor_memdup(digest, alloc_bytes); + + if (library_supports_digest(digest->algorithm)) { + result->d.ctx = PK11_CloneContext(digest->d.ctx); + } + + return result; +} + +/** Temporarily save the state of <b>digest</b> in <b>checkpoint</b>. + * Asserts that <b>digest</b> is a SHA1 digest object. + */ +void +crypto_digest_checkpoint(crypto_digest_checkpoint_t *checkpoint, + const crypto_digest_t *digest) +{ + const size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); + tor_assert(bytes <= sizeof(checkpoint->mem)); + if (library_supports_digest(digest->algorithm)) { + unsigned char *allocated; + allocated = PK11_SaveContextAlloc(digest->d.ctx, + (unsigned char *)checkpoint->mem, + sizeof(checkpoint->mem), + &checkpoint->bytes_used); + /* No allocation is allowed here. */ + tor_assert(allocated == checkpoint->mem); + return; + } + memcpy(checkpoint->mem, digest, bytes); +} + +/** Restore the state of <b>digest</b> from <b>checkpoint</b>. + * Asserts that <b>digest</b> is a SHA1 digest object. Requires that the + * state was previously stored with crypto_digest_checkpoint() */ +void +crypto_digest_restore(crypto_digest_t *digest, + const crypto_digest_checkpoint_t *checkpoint) +{ + const size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); + if (library_supports_digest(digest->algorithm)) { + SECStatus s = PK11_RestoreContext(digest->d.ctx, + (unsigned char *)checkpoint->mem, + checkpoint->bytes_used); + tor_assert(s == SECSuccess); + return; + } + memcpy(digest, checkpoint->mem, bytes); +} + +/** Replace the state of the digest object <b>into</b> with the state + * of the digest object <b>from</b>. Requires that 'into' and 'from' + * have the same digest type. + */ +void +crypto_digest_assign(crypto_digest_t *into, + const crypto_digest_t *from) +{ + tor_assert(into); + tor_assert(from); + tor_assert(into->algorithm == from->algorithm); + const size_t alloc_bytes = crypto_digest_alloc_bytes(from->algorithm); + if (library_supports_digest(from->algorithm)) { + PK11_DestroyContext(into->d.ctx, PR_TRUE); + into->d.ctx = PK11_CloneContext(from->d.ctx); + return; + } + memcpy(into,from,alloc_bytes); +} + +/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest + * at <b>digest_out</b> to the hash of the concatenation of those strings, + * plus the optional string <b>append</b>, computed with the algorithm + * <b>alg</b>. + * <b>out_len</b> must be \<= DIGEST512_LEN. */ +void +crypto_digest_smartlist(char *digest_out, size_t len_out, + const smartlist_t *lst, + const char *append, + digest_algorithm_t alg) +{ + crypto_digest_smartlist_prefix(digest_out, len_out, NULL, lst, append, alg); +} + +/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest + * at <b>digest_out</b> to the hash of the concatenation of: the + * optional string <b>prepend</b>, those strings, + * and the optional string <b>append</b>, computed with the algorithm + * <b>alg</b>. + * <b>len_out</b> must be \<= DIGEST512_LEN. */ +void +crypto_digest_smartlist_prefix(char *digest_out, size_t len_out, + const char *prepend, + const smartlist_t *lst, + const char *append, + digest_algorithm_t alg) +{ + crypto_digest_t *d = crypto_digest_new_internal(alg); + if (prepend) + crypto_digest_add_bytes(d, prepend, strlen(prepend)); + SMARTLIST_FOREACH(lst, const char *, cp, + crypto_digest_add_bytes(d, cp, strlen(cp))); + if (append) + crypto_digest_add_bytes(d, append, strlen(append)); + crypto_digest_get_digest(d, digest_out, len_out); + crypto_digest_free(d); +} + +/** Compute the HMAC-SHA-256 of the <b>msg_len</b> bytes in <b>msg</b>, using + * the <b>key</b> of length <b>key_len</b>. Store the DIGEST256_LEN-byte + * result in <b>hmac_out</b>. Asserts on failure. + */ +void +crypto_hmac_sha256(char *hmac_out, + const char *key, size_t key_len, + const char *msg, size_t msg_len) +{ + /* If we've got OpenSSL >=0.9.8 we can use its hmac implementation. */ + tor_assert(key_len < INT_MAX); + tor_assert(msg_len < INT_MAX); + tor_assert(hmac_out); + + PK11SlotInfo *slot = NULL; + PK11SymKey *symKey = NULL; + PK11Context *hmac = NULL; + + int ok = 0; + SECStatus s; + SECItem keyItem, paramItem; + keyItem.data = (unsigned char *)key; + keyItem.len = (unsigned)key_len; + paramItem.type = siBuffer; + paramItem.data = NULL; + paramItem.len = 0; + + slot = PK11_GetBestSlot(CKM_SHA256_HMAC, NULL); + if (!slot) + goto done; + symKey = PK11_ImportSymKey(slot, CKM_SHA256_HMAC, + PK11_OriginUnwrap, CKA_SIGN, &keyItem, NULL); + if (!symKey) + goto done; + + hmac = PK11_CreateContextBySymKey(CKM_SHA256_HMAC, CKA_SIGN, symKey, + ¶mItem); + if (!hmac) + goto done; + s = PK11_DigestBegin(hmac); + if (s != SECSuccess) + goto done; + s = PK11_DigestOp(hmac, (const unsigned char *)msg, (unsigned int)msg_len); + if (s != SECSuccess) + goto done; + unsigned int len=0; + s = PK11_DigestFinal(hmac, (unsigned char *)hmac_out, &len, DIGEST256_LEN); + if (s != SECSuccess || len != DIGEST256_LEN) + goto done; + ok = 1; + + done: + if (hmac) + PK11_DestroyContext(hmac, PR_TRUE); + if (symKey) + PK11_FreeSymKey(symKey); + if (slot) + PK11_FreeSlot(slot); + + tor_assert(ok); +} diff --git a/src/lib/crypt_ops/crypto_digest_openssl.c b/src/lib/crypt_ops/crypto_digest_openssl.c new file mode 100644 index 0000000000..11189c7fb2 --- /dev/null +++ b/src/lib/crypt_ops/crypto_digest_openssl.c @@ -0,0 +1,521 @@ +/* Copyright (c) 2001, Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file crypto_digest_openssl.c + * \brief Block of functions related with digest and xof utilities and + * operations (OpenSSL specific implementations). + **/ + +#include "lib/container/smartlist.h" +#include "lib/crypt_ops/crypto_digest.h" +#include "lib/crypt_ops/crypto_util.h" +#include "lib/log/log.h" +#include "lib/log/util_bug.h" + +#include "keccak-tiny/keccak-tiny.h" + +#include <stdlib.h> +#include <string.h> + +#include "lib/arch/bytes.h" + +#include "lib/crypt_ops/crypto_openssl_mgt.h" + +DISABLE_GCC_WARNING("-Wredundant-decls") + +#include <openssl/hmac.h> +#include <openssl/sha.h> + +ENABLE_GCC_WARNING("-Wredundant-decls") + +/* Crypto digest functions */ + +/** Compute the SHA1 digest of the <b>len</b> bytes on data stored in + * <b>m</b>. Write the DIGEST_LEN byte result into <b>digest</b>. + * Return 0 on success, -1 on failure. + */ +MOCK_IMPL(int, +crypto_digest,(char *digest, const char *m, size_t len)) +{ + tor_assert(m); + tor_assert(digest); + if (SHA1((const unsigned char*)m,len,(unsigned char*)digest) == NULL) { + return -1; + } + return 0; +} + +/** Compute a 256-bit digest of <b>len</b> bytes in data stored in <b>m</b>, + * using the algorithm <b>algorithm</b>. Write the DIGEST_LEN256-byte result + * into <b>digest</b>. Return 0 on success, -1 on failure. */ +int +crypto_digest256(char *digest, const char *m, size_t len, + digest_algorithm_t algorithm) +{ + tor_assert(m); + tor_assert(digest); + tor_assert(algorithm == DIGEST_SHA256 || algorithm == DIGEST_SHA3_256); + + int ret = 0; + if (algorithm == DIGEST_SHA256) { + ret = (SHA256((const uint8_t*)m,len,(uint8_t*)digest) != NULL); + } else { +#ifdef OPENSSL_HAS_SHA3 + unsigned int dlen = DIGEST256_LEN; + ret = EVP_Digest(m, len, (uint8_t*)digest, &dlen, EVP_sha3_256(), NULL); +#else + ret = (sha3_256((uint8_t *)digest, DIGEST256_LEN,(const uint8_t *)m, len) + > -1); +#endif /* defined(OPENSSL_HAS_SHA3) */ + } + + if (!ret) + return -1; + return 0; +} + +/** Compute a 512-bit digest of <b>len</b> bytes in data stored in <b>m</b>, + * using the algorithm <b>algorithm</b>. Write the DIGEST_LEN512-byte result + * into <b>digest</b>. Return 0 on success, -1 on failure. */ +int +crypto_digest512(char *digest, const char *m, size_t len, + digest_algorithm_t algorithm) +{ + tor_assert(m); + tor_assert(digest); + tor_assert(algorithm == DIGEST_SHA512 || algorithm == DIGEST_SHA3_512); + + int ret = 0; + if (algorithm == DIGEST_SHA512) { + ret = (SHA512((const unsigned char*)m,len,(unsigned char*)digest) + != NULL); + } else { +#ifdef OPENSSL_HAS_SHA3 + unsigned int dlen = DIGEST512_LEN; + ret = EVP_Digest(m, len, (uint8_t*)digest, &dlen, EVP_sha3_512(), NULL); +#else + ret = (sha3_512((uint8_t*)digest, DIGEST512_LEN, (const uint8_t*)m, len) + > -1); +#endif /* defined(OPENSSL_HAS_SHA3) */ + } + + if (!ret) + return -1; + return 0; +} + +/** Intermediate information about the digest of a stream of data. */ +struct crypto_digest_t { + digest_algorithm_t algorithm; /**< Which algorithm is in use? */ + /** State for the digest we're using. Only one member of the + * union is usable, depending on the value of <b>algorithm</b>. Note also + * that space for other members might not even be allocated! + */ + union { + SHA_CTX sha1; /**< state for SHA1 */ + SHA256_CTX sha2; /**< state for SHA256 */ + SHA512_CTX sha512; /**< state for SHA512 */ +#ifdef OPENSSL_HAS_SHA3 + EVP_MD_CTX *md; +#else + keccak_state sha3; /**< state for SHA3-[256,512] */ +#endif + } d; +}; + +#ifdef TOR_UNIT_TESTS + +digest_algorithm_t +crypto_digest_get_algorithm(crypto_digest_t *digest) +{ + tor_assert(digest); + + return digest->algorithm; +} + +#endif /* defined(TOR_UNIT_TESTS) */ + +/** + * Return the number of bytes we need to malloc in order to get a + * crypto_digest_t for <b>alg</b>, or the number of bytes we need to wipe + * when we free one. + */ +static size_t +crypto_digest_alloc_bytes(digest_algorithm_t alg) +{ + /** Helper: returns the number of bytes in the 'f' field of 'st' */ +#define STRUCT_FIELD_SIZE(st, f) (sizeof( ((st*)0)->f )) + /** Gives the length of crypto_digest_t through the end of the field 'd' */ +#define END_OF_FIELD(f) (offsetof(crypto_digest_t, f) + \ + STRUCT_FIELD_SIZE(crypto_digest_t, f)) + switch (alg) { + case DIGEST_SHA1: + return END_OF_FIELD(d.sha1); + case DIGEST_SHA256: + return END_OF_FIELD(d.sha2); + case DIGEST_SHA512: + return END_OF_FIELD(d.sha512); +#ifdef OPENSSL_HAS_SHA3 + case DIGEST_SHA3_256: FALLTHROUGH; + case DIGEST_SHA3_512: + return END_OF_FIELD(d.md); +#else + case DIGEST_SHA3_256: FALLTHROUGH; + case DIGEST_SHA3_512: + return END_OF_FIELD(d.sha3); +#endif /* defined(OPENSSL_HAS_SHA3) */ + default: + tor_assert(0); // LCOV_EXCL_LINE + return 0; // LCOV_EXCL_LINE + } +#undef END_OF_FIELD +#undef STRUCT_FIELD_SIZE +} + +/** + * Internal function: create and return a new digest object for 'algorithm'. + * Does not typecheck the algorithm. + */ +static crypto_digest_t * +crypto_digest_new_internal(digest_algorithm_t algorithm) +{ + crypto_digest_t *r = tor_malloc(crypto_digest_alloc_bytes(algorithm)); + r->algorithm = algorithm; + + switch (algorithm) + { + case DIGEST_SHA1: + SHA1_Init(&r->d.sha1); + break; + case DIGEST_SHA256: + SHA256_Init(&r->d.sha2); + break; + case DIGEST_SHA512: + SHA512_Init(&r->d.sha512); + break; +#ifdef OPENSSL_HAS_SHA3 + case DIGEST_SHA3_256: + r->d.md = EVP_MD_CTX_new(); + if (!EVP_DigestInit(r->d.md, EVP_sha3_256())) { + crypto_digest_free(r); + return NULL; + } + break; + case DIGEST_SHA3_512: + r->d.md = EVP_MD_CTX_new(); + if (!EVP_DigestInit(r->d.md, EVP_sha3_512())) { + crypto_digest_free(r); + return NULL; + } + break; +#else /* !defined(OPENSSL_HAS_SHA3) */ + case DIGEST_SHA3_256: + keccak_digest_init(&r->d.sha3, 256); + break; + case DIGEST_SHA3_512: + keccak_digest_init(&r->d.sha3, 512); + break; +#endif /* defined(OPENSSL_HAS_SHA3) */ + default: + tor_assert_unreached(); + } + + return r; +} + +/** Allocate and return a new digest object to compute SHA1 digests. + */ +crypto_digest_t * +crypto_digest_new(void) +{ + return crypto_digest_new_internal(DIGEST_SHA1); +} + +/** Allocate and return a new digest object to compute 256-bit digests + * using <b>algorithm</b>. + * + * C_RUST_COUPLED: `external::crypto_digest::crypto_digest256_new` + * C_RUST_COUPLED: `crypto::digest::Sha256::default` + */ +crypto_digest_t * +crypto_digest256_new(digest_algorithm_t algorithm) +{ + tor_assert(algorithm == DIGEST_SHA256 || algorithm == DIGEST_SHA3_256); + return crypto_digest_new_internal(algorithm); +} + +/** Allocate and return a new digest object to compute 512-bit digests + * using <b>algorithm</b>. */ +crypto_digest_t * +crypto_digest512_new(digest_algorithm_t algorithm) +{ + tor_assert(algorithm == DIGEST_SHA512 || algorithm == DIGEST_SHA3_512); + return crypto_digest_new_internal(algorithm); +} + +/** Deallocate a digest object. + */ +void +crypto_digest_free_(crypto_digest_t *digest) +{ + if (!digest) + return; +#ifdef OPENSSL_HAS_SHA3 + if (digest->algorithm == DIGEST_SHA3_256 || + digest->algorithm == DIGEST_SHA3_512) { + if (digest->d.md) { + EVP_MD_CTX_free(digest->d.md); + } + } +#endif /* defined(OPENSSL_HAS_SHA3) */ + size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); + memwipe(digest, 0, bytes); + tor_free(digest); +} + +/** Add <b>len</b> bytes from <b>data</b> to the digest object. + * + * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_add_bytess` + * C_RUST_COUPLED: `crypto::digest::Sha256::process` + */ +void +crypto_digest_add_bytes(crypto_digest_t *digest, const char *data, + size_t len) +{ + tor_assert(digest); + tor_assert(data); + /* Using the SHA*_*() calls directly means we don't support doing + * SHA in hardware. But so far the delay of getting the question + * to the hardware, and hearing the answer, is likely higher than + * just doing it ourselves. Hashes are fast. + */ + switch (digest->algorithm) { + case DIGEST_SHA1: + SHA1_Update(&digest->d.sha1, (void*)data, len); + break; + case DIGEST_SHA256: + SHA256_Update(&digest->d.sha2, (void*)data, len); + break; + case DIGEST_SHA512: + SHA512_Update(&digest->d.sha512, (void*)data, len); + break; +#ifdef OPENSSL_HAS_SHA3 + case DIGEST_SHA3_256: FALLTHROUGH; + case DIGEST_SHA3_512: { + int r = EVP_DigestUpdate(digest->d.md, data, len); + tor_assert(r); + } + break; +#else /* !defined(OPENSSL_HAS_SHA3) */ + case DIGEST_SHA3_256: FALLTHROUGH; + case DIGEST_SHA3_512: + keccak_digest_update(&digest->d.sha3, (const uint8_t *)data, len); + break; +#endif /* defined(OPENSSL_HAS_SHA3) */ + default: + /* LCOV_EXCL_START */ + tor_fragile_assert(); + break; + /* LCOV_EXCL_STOP */ + } +} + +/** Compute the hash of the data that has been passed to the digest + * object; write the first out_len bytes of the result to <b>out</b>. + * <b>out_len</b> must be \<= DIGEST512_LEN. + * + * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_get_digest` + * C_RUST_COUPLED: `impl digest::FixedOutput for Sha256` + */ +void +crypto_digest_get_digest(crypto_digest_t *digest, + char *out, size_t out_len) +{ + unsigned char r[DIGEST512_LEN]; + tor_assert(digest); + tor_assert(out); + tor_assert(out_len <= crypto_digest_algorithm_get_length(digest->algorithm)); + + /* The SHA-3 code handles copying into a temporary ctx, and also can handle + * short output buffers by truncating appropriately. */ + if (digest->algorithm == DIGEST_SHA3_256 || + digest->algorithm == DIGEST_SHA3_512) { +#ifdef OPENSSL_HAS_SHA3 + unsigned dlen = (unsigned) + crypto_digest_algorithm_get_length(digest->algorithm); + EVP_MD_CTX *tmp = EVP_MD_CTX_new(); + EVP_MD_CTX_copy(tmp, digest->d.md); + memset(r, 0xff, sizeof(r)); + int res = EVP_DigestFinal(tmp, r, &dlen); + EVP_MD_CTX_free(tmp); + tor_assert(res == 1); + goto done; +#else /* !defined(OPENSSL_HAS_SHA3) */ + /* Tiny-Keccak handles copying into a temporary ctx, and also can handle + * short output buffers by truncating appropriately. */ + keccak_digest_sum(&digest->d.sha3, (uint8_t *)out, out_len); + return; +#endif /* defined(OPENSSL_HAS_SHA3) */ + } + + const size_t alloc_bytes = crypto_digest_alloc_bytes(digest->algorithm); + crypto_digest_t tmpenv; + /* memcpy into a temporary ctx, since SHA*_Final clears the context */ + memcpy(&tmpenv, digest, alloc_bytes); + switch (digest->algorithm) { + case DIGEST_SHA1: + SHA1_Final(r, &tmpenv.d.sha1); + break; + case DIGEST_SHA256: + SHA256_Final(r, &tmpenv.d.sha2); + break; + case DIGEST_SHA512: + SHA512_Final(r, &tmpenv.d.sha512); + break; +//LCOV_EXCL_START + case DIGEST_SHA3_256: FALLTHROUGH; + case DIGEST_SHA3_512: + default: + log_warn(LD_BUG, "Handling unexpected algorithm %d", digest->algorithm); + /* This is fatal, because it should never happen. */ + tor_assert_unreached(); + break; +//LCOV_EXCL_STOP + } +#ifdef OPENSSL_HAS_SHA3 + done: +#endif + memcpy(out, r, out_len); + memwipe(r, 0, sizeof(r)); +} + +/** Allocate and return a new digest object with the same state as + * <b>digest</b> + * + * C_RUST_COUPLED: `external::crypto_digest::crypto_digest_dup` + * C_RUST_COUPLED: `impl Clone for crypto::digest::Sha256` + */ +crypto_digest_t * +crypto_digest_dup(const crypto_digest_t *digest) +{ + tor_assert(digest); + const size_t alloc_bytes = crypto_digest_alloc_bytes(digest->algorithm); + crypto_digest_t *result = tor_memdup(digest, alloc_bytes); + +#ifdef OPENSSL_HAS_SHA3 + if (digest->algorithm == DIGEST_SHA3_256 || + digest->algorithm == DIGEST_SHA3_512) { + result->d.md = EVP_MD_CTX_new(); + EVP_MD_CTX_copy(result->d.md, digest->d.md); + } +#endif /* defined(OPENSSL_HAS_SHA3) */ + return result; +} + +/** Temporarily save the state of <b>digest</b> in <b>checkpoint</b>. + * Asserts that <b>digest</b> is a SHA1 digest object. + */ +void +crypto_digest_checkpoint(crypto_digest_checkpoint_t *checkpoint, + const crypto_digest_t *digest) +{ + const size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); + tor_assert(bytes <= sizeof(checkpoint->mem)); + memcpy(checkpoint->mem, digest, bytes); +} + +/** Restore the state of <b>digest</b> from <b>checkpoint</b>. + * Asserts that <b>digest</b> is a SHA1 digest object. Requires that the + * state was previously stored with crypto_digest_checkpoint() */ +void +crypto_digest_restore(crypto_digest_t *digest, + const crypto_digest_checkpoint_t *checkpoint) +{ + const size_t bytes = crypto_digest_alloc_bytes(digest->algorithm); + memcpy(digest, checkpoint->mem, bytes); +} + +/** Replace the state of the digest object <b>into</b> with the state + * of the digest object <b>from</b>. Requires that 'into' and 'from' + * have the same digest type. + */ +void +crypto_digest_assign(crypto_digest_t *into, + const crypto_digest_t *from) +{ + tor_assert(into); + tor_assert(from); + tor_assert(into->algorithm == from->algorithm); + const size_t alloc_bytes = crypto_digest_alloc_bytes(from->algorithm); + +#ifdef OPENSSL_HAS_SHA3 + if (from->algorithm == DIGEST_SHA3_256 || + from->algorithm == DIGEST_SHA3_512) { + EVP_MD_CTX_copy(into->d.md, from->d.md); + return; + } +#endif /* defined(OPENSSL_HAS_SHA3) */ + + memcpy(into,from,alloc_bytes); +} + +/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest + * at <b>digest_out</b> to the hash of the concatenation of those strings, + * plus the optional string <b>append</b>, computed with the algorithm + * <b>alg</b>. + * <b>out_len</b> must be \<= DIGEST512_LEN. */ +void +crypto_digest_smartlist(char *digest_out, size_t len_out, + const smartlist_t *lst, + const char *append, + digest_algorithm_t alg) +{ + crypto_digest_smartlist_prefix(digest_out, len_out, NULL, lst, append, alg); +} + +/** Given a list of strings in <b>lst</b>, set the <b>len_out</b>-byte digest + * at <b>digest_out</b> to the hash of the concatenation of: the + * optional string <b>prepend</b>, those strings, + * and the optional string <b>append</b>, computed with the algorithm + * <b>alg</b>. + * <b>len_out</b> must be \<= DIGEST512_LEN. */ +void +crypto_digest_smartlist_prefix(char *digest_out, size_t len_out, + const char *prepend, + const smartlist_t *lst, + const char *append, + digest_algorithm_t alg) +{ + crypto_digest_t *d = crypto_digest_new_internal(alg); + if (prepend) + crypto_digest_add_bytes(d, prepend, strlen(prepend)); + SMARTLIST_FOREACH(lst, const char *, cp, + crypto_digest_add_bytes(d, cp, strlen(cp))); + if (append) + crypto_digest_add_bytes(d, append, strlen(append)); + crypto_digest_get_digest(d, digest_out, len_out); + crypto_digest_free(d); +} + +/** Compute the HMAC-SHA-256 of the <b>msg_len</b> bytes in <b>msg</b>, using + * the <b>key</b> of length <b>key_len</b>. Store the DIGEST256_LEN-byte + * result in <b>hmac_out</b>. Asserts on failure. + */ +void +crypto_hmac_sha256(char *hmac_out, + const char *key, size_t key_len, + const char *msg, size_t msg_len) +{ + /* If we've got OpenSSL >=0.9.8 we can use its hmac implementation. */ + tor_assert(key_len < INT_MAX); + tor_assert(msg_len < INT_MAX); + tor_assert(hmac_out); + unsigned char *rv = NULL; + rv = HMAC(EVP_sha256(), key, (int)key_len, (unsigned char*)msg, (int)msg_len, + (unsigned char*)hmac_out, NULL); + tor_assert(rv); +} diff --git a/src/lib/crypt_ops/crypto_ed25519.c b/src/lib/crypt_ops/crypto_ed25519.c index 0a442bb739..f242c7011e 100644 --- a/src/lib/crypt_ops/crypto_ed25519.c +++ b/src/lib/crypt_ops/crypto_ed25519.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2013-2019, The Tor Project, Inc. */ +/* Copyright (c) 2013-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -226,7 +226,7 @@ ed25519_keypair_generate(ed25519_keypair_t *keypair_out, int extra_strong) int ed25519_public_key_is_zero(const ed25519_public_key_t *pubkey) { - return tor_mem_is_zero((char*)pubkey->pubkey, ED25519_PUBKEY_LEN); + return safe_mem_is_zero((char*)pubkey->pubkey, ED25519_PUBKEY_LEN); } /* Return a heap-allocated array that contains <b>msg</b> prefixed by the diff --git a/src/lib/crypt_ops/crypto_ed25519.h b/src/lib/crypt_ops/crypto_ed25519.h index 325b28244d..346de464e3 100644 --- a/src/lib/crypt_ops/crypto_ed25519.h +++ b/src/lib/crypt_ops/crypto_ed25519.h @@ -1,4 +1,4 @@ -/* Copyright (c) 2012-2019, The Tor Project, Inc. */ +/* Copyright (c) 2012-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_format.c b/src/lib/crypt_ops/crypto_format.c index 84f73e5272..92b8b9372e 100644 --- a/src/lib/crypt_ops/crypto_format.c +++ b/src/lib/crypt_ops/crypto_format.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -104,7 +104,7 @@ crypto_read_tagged_contents_from_file(const char *fname, prefix[32] = 0; /* Check type, extract tag. */ if (strcmpstart(prefix, "== ") || strcmpend(prefix, " ==") || - ! tor_mem_is_zero(prefix+strlen(prefix), 32-strlen(prefix))) { + ! fast_mem_is_zero(prefix+strlen(prefix), 32-strlen(prefix))) { saved_errno = EINVAL; goto end; } @@ -131,20 +131,27 @@ crypto_read_tagged_contents_from_file(const char *fname, return r; } -/** Encode <b>pkey</b> as a base64-encoded string, without trailing "=" +/** Encode <b>pkey</b> as a base64-encoded string, including trailing "=" * characters, in the buffer <b>output</b>, which must have at least - * CURVE25519_BASE64_PADDED_LEN+1 bytes available. Return 0 on success, -1 on - * failure. */ -int + * CURVE25519_BASE64_PADDED_LEN+1 bytes available. + * Can not fail. + * + * Careful! CURVE25519_BASE64_PADDED_LEN is one byte longer than + * ED25519_BASE64_LEN. + */ +void curve25519_public_to_base64(char *output, const curve25519_public_key_t *pkey) { char buf[128]; - base64_encode(buf, sizeof(buf), - (const char*)pkey->public_key, CURVE25519_PUBKEY_LEN, 0); - buf[CURVE25519_BASE64_PADDED_LEN] = '\0'; + int n = base64_encode(buf, sizeof(buf), + (const char*)pkey->public_key, + CURVE25519_PUBKEY_LEN, 0); + /* These asserts should always succeed, unless there is a bug in + * base64_encode(). */ + tor_assert(n == CURVE25519_BASE64_PADDED_LEN); + tor_assert(buf[CURVE25519_BASE64_PADDED_LEN] == '\0'); memcpy(output, buf, CURVE25519_BASE64_PADDED_LEN+1); - return 0; } /** Try to decode a base64-encoded curve25519 public key from <b>input</b> @@ -181,8 +188,7 @@ ed25519_fmt(const ed25519_public_key_t *pkey) if (ed25519_public_key_is_zero(pkey)) { strlcpy(formatted, "<unset>", sizeof(formatted)); } else { - int r = ed25519_public_to_base64(formatted, pkey); - tor_assert(!r); + ed25519_public_to_base64(formatted, pkey); } } else { strlcpy(formatted, "<null>", sizeof(formatted)); @@ -202,28 +208,35 @@ ed25519_public_from_base64(ed25519_public_key_t *pkey, /** Encode the public key <b>pkey</b> into the buffer at <b>output</b>, * which must have space for ED25519_BASE64_LEN bytes of encoded key, - * plus one byte for a terminating NUL. Return 0 on success, -1 on failure. + * plus one byte for a terminating NUL. + * Can not fail. + * + * Careful! ED25519_BASE64_LEN is one byte shorter than + * CURVE25519_BASE64_PADDED_LEN. */ -int +void ed25519_public_to_base64(char *output, const ed25519_public_key_t *pkey) { - return digest256_to_base64(output, (const char *)pkey->pubkey); + digest256_to_base64(output, (const char *)pkey->pubkey); } /** Encode the signature <b>sig</b> into the buffer at <b>output</b>, * which must have space for ED25519_SIG_BASE64_LEN bytes of encoded signature, - * plus one byte for a terminating NUL. Return 0 on success, -1 on failure. + * plus one byte for a terminating NUL. + * Can not fail. */ -int +void ed25519_signature_to_base64(char *output, const ed25519_signature_t *sig) { char buf[256]; int n = base64_encode_nopad(buf, sizeof(buf), sig->sig, ED25519_SIG_LEN); + /* These asserts should always succeed, unless there is a bug in + * base64_encode_nopad(). */ tor_assert(n == ED25519_SIG_BASE64_LEN); + tor_assert(buf[ED25519_SIG_BASE64_LEN] == '\0'); memcpy(output, buf, ED25519_SIG_BASE64_LEN+1); - return 0; } /** Try to decode the string <b>input</b> into an ed25519 signature. On @@ -233,16 +246,11 @@ int ed25519_signature_from_base64(ed25519_signature_t *sig, const char *input) { - if (strlen(input) != ED25519_SIG_BASE64_LEN) return -1; - char buf[ED25519_SIG_BASE64_LEN+3]; - memcpy(buf, input, ED25519_SIG_BASE64_LEN); - buf[ED25519_SIG_BASE64_LEN+0] = '='; - buf[ED25519_SIG_BASE64_LEN+1] = '='; - buf[ED25519_SIG_BASE64_LEN+2] = 0; char decoded[128]; - int n = base64_decode(decoded, sizeof(decoded), buf, strlen(buf)); + int n = base64_decode(decoded, sizeof(decoded), input, + ED25519_SIG_BASE64_LEN); if (n < 0 || n != ED25519_SIG_LEN) return -1; memcpy(sig->sig, decoded, ED25519_SIG_LEN); @@ -250,24 +258,26 @@ ed25519_signature_from_base64(ed25519_signature_t *sig, return 0; } -/** Base64 encode DIGEST_LINE bytes from <b>digest</b>, remove the trailing = +/** Base64 encode DIGEST_LEN bytes from <b>digest</b>, remove the trailing = * characters, and store the nul-terminated result in the first - * BASE64_DIGEST_LEN+1 bytes of <b>d64</b>. */ -/* XXXX unify with crypto_format.c code */ -int + * BASE64_DIGEST_LEN+1 bytes of <b>d64</b>. + * Can not fail. */ +void digest_to_base64(char *d64, const char *digest) { char buf[256]; - base64_encode(buf, sizeof(buf), digest, DIGEST_LEN, 0); - buf[BASE64_DIGEST_LEN] = '\0'; + int n = base64_encode_nopad(buf, sizeof(buf), + (const uint8_t *)digest, DIGEST_LEN); + /* These asserts should always succeed, unless there is a bug in + * base64_encode_nopad(). */ + tor_assert(n == BASE64_DIGEST_LEN); + tor_assert(buf[BASE64_DIGEST_LEN] == '\0'); memcpy(d64, buf, BASE64_DIGEST_LEN+1); - return 0; } /** Given a base64 encoded, nul-terminated digest in <b>d64</b> (without * trailing newline or = characters), decode it and store the result in the * first DIGEST_LEN bytes at <b>digest</b>. */ -/* XXXX unify with crypto_format.c code */ int digest_from_base64(char *digest, const char *d64) { @@ -279,22 +289,24 @@ digest_from_base64(char *digest, const char *d64) /** Base64 encode DIGEST256_LINE bytes from <b>digest</b>, remove the * trailing = characters, and store the nul-terminated result in the first - * BASE64_DIGEST256_LEN+1 bytes of <b>d64</b>. */ - /* XXXX unify with crypto_format.c code */ -int + * BASE64_DIGEST256_LEN+1 bytes of <b>d64</b>. + * Can not fail. */ +void digest256_to_base64(char *d64, const char *digest) { char buf[256]; - base64_encode(buf, sizeof(buf), digest, DIGEST256_LEN, 0); - buf[BASE64_DIGEST256_LEN] = '\0'; + int n = base64_encode_nopad(buf, sizeof(buf), + (const uint8_t *)digest, DIGEST256_LEN); + /* These asserts should always succeed, unless there is a bug in + * base64_encode_nopad(). */ + tor_assert(n == BASE64_DIGEST256_LEN); + tor_assert(buf[BASE64_DIGEST256_LEN] == '\0'); memcpy(d64, buf, BASE64_DIGEST256_LEN+1); - return 0; } /** Given a base64 encoded, nul-terminated digest in <b>d64</b> (without * trailing newline or = characters), decode it and store the result in the * first DIGEST256_LEN bytes at <b>digest</b>. */ -/* XXXX unify with crypto_format.c code */ int digest256_from_base64(char *digest, const char *d64) { diff --git a/src/lib/crypt_ops/crypto_format.h b/src/lib/crypt_ops/crypto_format.h index fe852e6a61..91da137e1c 100644 --- a/src/lib/crypt_ops/crypto_format.h +++ b/src/lib/crypt_ops/crypto_format.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -33,18 +33,18 @@ ssize_t crypto_read_tagged_contents_from_file(const char *fname, int ed25519_public_from_base64(struct ed25519_public_key_t *pkey, const char *input); -int ed25519_public_to_base64(char *output, - const struct ed25519_public_key_t *pkey); +void ed25519_public_to_base64(char *output, + const struct ed25519_public_key_t *pkey); const char *ed25519_fmt(const struct ed25519_public_key_t *pkey); int ed25519_signature_from_base64(struct ed25519_signature_t *sig, const char *input); -int ed25519_signature_to_base64(char *output, - const struct ed25519_signature_t *sig); +void ed25519_signature_to_base64(char *output, + const struct ed25519_signature_t *sig); -int digest_to_base64(char *d64, const char *digest); +void digest_to_base64(char *d64, const char *digest); int digest_from_base64(char *digest, const char *d64); -int digest256_to_base64(char *d64, const char *digest); +void digest256_to_base64(char *d64, const char *digest); int digest256_from_base64(char *digest, const char *d64); #endif /* !defined(TOR_CRYPTO_FORMAT_H) */ diff --git a/src/lib/crypt_ops/crypto_hkdf.c b/src/lib/crypt_ops/crypto_hkdf.c index fd2e701651..7b02820087 100644 --- a/src/lib/crypt_ops/crypto_hkdf.c +++ b/src/lib/crypt_ops/crypto_hkdf.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -25,7 +25,7 @@ #include <openssl/kdf.h> #define HAVE_OPENSSL_HKDF 1 #endif -#endif +#endif /* defined(ENABLE_OPENSSL) */ #include <string.h> @@ -109,7 +109,7 @@ crypto_expand_key_material_rfc5869_sha256_openssl( return 0; } -#else +#else /* !defined(HAVE_OPENSSL_HKDF) */ /** * Perform RFC5869 HKDF computation using our own legacy implementation. @@ -166,7 +166,7 @@ crypto_expand_key_material_rfc5869_sha256_legacy( memwipe(mac, 0, sizeof(mac)); return 0; } -#endif +#endif /* defined(HAVE_OPENSSL_HKDF) */ /** Expand some secret key material according to RFC5869, using SHA256 as the * underlying hash. The <b>key_in_len</b> bytes at <b>key_in</b> are the @@ -191,11 +191,11 @@ crypto_expand_key_material_rfc5869_sha256( salt_in_len, info_in, info_in_len, key_out, key_out_len); -#else +#else /* !defined(HAVE_OPENSSL_HKDF) */ return crypto_expand_key_material_rfc5869_sha256_legacy(key_in, key_in_len, salt_in, salt_in_len, info_in, info_in_len, key_out, key_out_len); -#endif +#endif /* defined(HAVE_OPENSSL_HKDF) */ } diff --git a/src/lib/crypt_ops/crypto_hkdf.h b/src/lib/crypt_ops/crypto_hkdf.h index 2994d18e3d..404f548774 100644 --- a/src/lib/crypt_ops/crypto_hkdf.h +++ b/src/lib/crypt_ops/crypto_hkdf.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_init.c b/src/lib/crypt_ops/crypto_init.c index 329c264af6..a836bd8645 100644 --- a/src/lib/crypt_ops/crypto_init.c +++ b/src/lib/crypt_ops/crypto_init.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -12,6 +12,8 @@ #include "orconfig.h" +#define CRYPTO_PRIVATE + #include "lib/crypt_ops/crypto_init.h" #include "lib/crypt_ops/crypto_curve25519.h" @@ -20,8 +22,14 @@ #include "lib/crypt_ops/crypto_openssl_mgt.h" #include "lib/crypt_ops/crypto_nss_mgt.h" #include "lib/crypt_ops/crypto_rand.h" +#include "lib/crypt_ops/crypto_sys.h" +#include "lib/crypt_ops/crypto_options_st.h" +#include "lib/conf/conftypes.h" +#include "lib/log/util_bug.h" + +#include "lib/subsys/subsys.h" -#include "siphash.h" +#include "ext/siphash.h" /** Boolean: has our crypto library been initialized? (early phase) */ static int crypto_early_initialized_ = 0; @@ -66,6 +74,8 @@ crypto_early_init(void) if (crypto_init_siphash_key() < 0) return -1; + crypto_rand_fast_init(); + curve25519_init(); ed25519_init(); } @@ -92,7 +102,7 @@ crypto_global_init(int useAccel, const char *accelName, const char *accelDir) (void)useAccel; (void)accelName; (void)accelDir; -#endif +#endif /* defined(ENABLE_OPENSSL) */ #ifdef ENABLE_NSS if (crypto_nss_late_init() < 0) return -1; @@ -108,6 +118,7 @@ crypto_thread_cleanup(void) #ifdef ENABLE_OPENSSL crypto_openssl_thread_cleanup(); #endif + destroy_thread_fast_rng(); } /** @@ -126,6 +137,8 @@ crypto_global_cleanup(void) crypto_nss_global_cleanup(); #endif + crypto_rand_fast_shutdown(); + crypto_early_initialized_ = 0; crypto_global_initialized_ = 0; have_seeded_siphash = 0; @@ -142,6 +155,12 @@ crypto_prefork(void) #ifdef ENABLE_NSS crypto_nss_prefork(); #endif + /* It is not safe to share a fast_rng object across a fork boundary unless + * we actually have zero-on-fork support in map_anon.c. If we have + * drop-on-fork support, we will crash; if we have neither, we will yield + * a copy of the parent process's rng, which is scary and insecure. + */ + destroy_thread_fast_rng(); } /** Run operations that the crypto library requires to be happy again @@ -202,3 +221,111 @@ tor_is_using_nss(void) return 0; #endif } + +static int +subsys_crypto_initialize(void) +{ + if (crypto_early_init() < 0) + return -1; + crypto_dh_init(); + return 0; +} + +static void +subsys_crypto_shutdown(void) +{ + crypto_global_cleanup(); +} + +static void +subsys_crypto_prefork(void) +{ + crypto_prefork(); +} + +static void +subsys_crypto_postfork(void) +{ + crypto_postfork(); +} + +static void +subsys_crypto_thread_cleanup(void) +{ + crypto_thread_cleanup(); +} + +/** Magic number for crypto_options_t. */ +#define CRYPTO_OPTIONS_MAGIC 0x68757368 + +/** + * Return 0 if <b>arg</b> is a valid crypto_options_t. Otherwise return -1 + * and set *<b>msg_out</b> to a freshly allocated error string. + **/ +static int +crypto_options_validate(const void *arg, char **msg_out) +{ + const crypto_options_t *opt = arg; + tor_assert(opt->magic == CRYPTO_OPTIONS_MAGIC); + tor_assert(msg_out); + + if (opt->AccelDir && !opt->AccelName) { + *msg_out = tor_strdup("Can't use hardware crypto accelerator dir " + "without engine name."); + return -1; + } + + return 0; +} + +/* Declare the options field table for crypto_options */ +#define CONF_CONTEXT LL_TABLE +#include "lib/crypt_ops/crypto_options.inc" +#undef CONF_CONTEXT + +/** + * Declares the configuration options for this module. + **/ +static const config_format_t crypto_options_fmt = { + .size = sizeof(crypto_options_t), + .magic = { "crypto_options_t", + CRYPTO_OPTIONS_MAGIC, + offsetof(crypto_options_t, magic) }, + .vars = crypto_options_t_vars, + .validate_fn = crypto_options_validate, +}; + +/** + * Invoked from subsysmgr.c when a new set of options arrives. + **/ +static int +crypto_set_options(void *arg) +{ + const crypto_options_t *options = arg; + const bool hardware_accel = options->HardwareAccel || options->AccelName; + + // This call already checks for crypto_global_initialized_, so it + // will only initialize the subsystem the first time it's called. + if (crypto_global_init(hardware_accel, + options->AccelName, + options->AccelDir)) { + log_err(LD_BUG, "Unable to initialize the crypto subsystem. Exiting."); + return -1; + } + return 0; +} + +const struct subsys_fns_t sys_crypto = { + .name = "crypto", + SUBSYS_DECLARE_LOCATION(), + .supported = true, + .level = -60, + .initialize = subsys_crypto_initialize, + .shutdown = subsys_crypto_shutdown, + .prefork = subsys_crypto_prefork, + .postfork = subsys_crypto_postfork, + .thread_cleanup = subsys_crypto_thread_cleanup, + + .options_format = &crypto_options_fmt, + .set_options = crypto_set_options, +}; diff --git a/src/lib/crypt_ops/crypto_init.h b/src/lib/crypt_ops/crypto_init.h index 540d08eb56..b11e2e34bf 100644 --- a/src/lib/crypt_ops/crypto_init.h +++ b/src/lib/crypt_ops/crypto_init.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -33,4 +33,4 @@ const char *crypto_get_header_version_string(void); int tor_is_using_nss(void); -#endif /* !defined(TOR_CRYPTO_H) */ +#endif /* !defined(TOR_CRYPTO_INIT_H) */ diff --git a/src/lib/crypt_ops/crypto_nss_mgt.c b/src/lib/crypt_ops/crypto_nss_mgt.c index 0179126e38..d82e51249c 100644 --- a/src/lib/crypt_ops/crypto_nss_mgt.c +++ b/src/lib/crypt_ops/crypto_nss_mgt.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -16,7 +16,7 @@ #include "lib/log/util_bug.h" #include "lib/string/printf.h" -DISABLE_GCC_WARNING(strict-prototypes) +DISABLE_GCC_WARNING("-Wstrict-prototypes") #include <nss.h> #include <pk11func.h> #include <ssl.h> @@ -24,7 +24,7 @@ DISABLE_GCC_WARNING(strict-prototypes) #include <prerror.h> #include <prtypes.h> #include <prinit.h> -ENABLE_GCC_WARNING(strict-prototypes) +ENABLE_GCC_WARNING("-Wstrict-prototypes") const char * crypto_nss_get_version_str(void) diff --git a/src/lib/crypt_ops/crypto_nss_mgt.h b/src/lib/crypt_ops/crypto_nss_mgt.h index 72fd2a1229..8686b1b8aa 100644 --- a/src/lib/crypt_ops/crypto_nss_mgt.h +++ b/src/lib/crypt_ops/crypto_nss_mgt.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -29,6 +29,6 @@ void crypto_nss_global_cleanup(void); void crypto_nss_prefork(void); void crypto_nss_postfork(void); -#endif +#endif /* defined(ENABLE_NSS) */ -#endif /* !defined(TOR_CRYPTO_NSS_H) */ +#endif /* !defined(TOR_CRYPTO_NSS_MGT_H) */ diff --git a/src/lib/crypt_ops/crypto_ope.c b/src/lib/crypt_ops/crypto_ope.c index 2186d2a939..4cacb3dd98 100644 --- a/src/lib/crypt_ops/crypto_ope.c +++ b/src/lib/crypt_ops/crypto_ope.c @@ -1,8 +1,9 @@ -/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* Copyright (c) 2018-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** - * A rudimentary order-preserving encryption scheme. + * @file crypto_ope.c + * @brief A rudimentary order-preserving encryption scheme. * * To compute the encryption of N, this scheme uses an AES-CTR stream to * generate M-byte values, and adds the first N of them together. (+1 each to @@ -57,9 +58,9 @@ ope_val_from_le(ope_val_t x) ((x) >> 8) | (((x)&0xff) << 8); } -#else +#else /* !defined(WORDS_BIGENDIAN) */ #define ope_val_from_le(x) (x) -#endif +#endif /* defined(WORDS_BIGENDIAN) */ /** * Return a new AES256-CTR stream cipher object for <b>ope</b>, ready to yield @@ -143,7 +144,7 @@ crypto_ope_new(const uint8_t *key) return ope; } -/** Free all storage held in <>ope</b>. */ +/** Free all storage held in <b>ope</b>. */ void crypto_ope_free_(crypto_ope_t *ope) { diff --git a/src/lib/crypt_ops/crypto_ope.h b/src/lib/crypt_ops/crypto_ope.h index 610d956335..7498ea6a2e 100644 --- a/src/lib/crypt_ops/crypto_ope.h +++ b/src/lib/crypt_ops/crypto_ope.h @@ -1,6 +1,11 @@ -/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* Copyright (c) 2018-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ +/** + * @file crypto_ope.h + * @brief header for crypto_ope.c + **/ + #ifndef CRYPTO_OPE_H #define CRYPTO_OPE_H @@ -37,10 +42,10 @@ void crypto_ope_free_(crypto_ope_t *ope); uint64_t crypto_ope_encrypt(const crypto_ope_t *ope, int plaintext); #ifdef CRYPTO_OPE_PRIVATE -struct aes_cnt_cipher; -STATIC struct aes_cnt_cipher *ope_get_cipher(const crypto_ope_t *ope, +struct aes_cnt_cipher_t; +STATIC struct aes_cnt_cipher_t *ope_get_cipher(const crypto_ope_t *ope, uint32_t initial_idx); -STATIC uint64_t sum_values_from_cipher(struct aes_cnt_cipher *c, size_t n); -#endif +STATIC uint64_t sum_values_from_cipher(struct aes_cnt_cipher_t *c, size_t n); +#endif /* defined(CRYPTO_OPE_PRIVATE) */ -#endif +#endif /* !defined(CRYPTO_OPE_H) */ diff --git a/src/lib/crypt_ops/crypto_openssl_mgt.c b/src/lib/crypt_ops/crypto_openssl_mgt.c index e7d6084f6c..065cbca1cc 100644 --- a/src/lib/crypt_ops/crypto_openssl_mgt.c +++ b/src/lib/crypt_ops/crypto_openssl_mgt.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -21,7 +21,7 @@ #include "lib/testsupport/testsupport.h" #include "lib/thread/threads.h" -DISABLE_GCC_WARNING(redundant-decls) +DISABLE_GCC_WARNING("-Wredundant-decls") #include <openssl/err.h> #include <openssl/rsa.h> @@ -36,7 +36,7 @@ DISABLE_GCC_WARNING(redundant-decls) #include <openssl/crypto.h> #include <openssl/ssl.h> -ENABLE_GCC_WARNING(redundant-decls) +ENABLE_GCC_WARNING("-Wredundant-decls") #include <string.h> @@ -130,10 +130,12 @@ crypto_openssl_get_header_version_str(void) return crypto_openssl_header_version_str; } +#ifndef COCCI #ifndef OPENSSL_THREADS -#error OpenSSL has been built without thread support. Tor requires an \ - OpenSSL library with thread support enabled. +#error "OpenSSL has been built without thread support. Tor requires an \ + OpenSSL library with thread support enabled." #endif +#endif /* !defined(COCCI) */ #ifndef NEW_THREAD_API /** Helper: OpenSSL uses this callback to manipulate mutexes. */ @@ -185,6 +187,10 @@ crypto_openssl_free_all(void) tor_free(crypto_openssl_version_str); tor_free(crypto_openssl_header_version_str); + /* Destroying a locked mutex is undefined behaviour. This mutex may be + * locked, because multiple threads can access it. But we need to destroy + * it, otherwise re-initialisation will trigger undefined behaviour. + * See #31735 for details. */ #ifndef NEW_THREAD_API if (n_openssl_mutexes_) { int n = n_openssl_mutexes_; @@ -209,10 +215,10 @@ crypto_openssl_early_init(void) OPENSSL_INIT_LOAD_CRYPTO_STRINGS | OPENSSL_INIT_ADD_ALL_CIPHERS | OPENSSL_INIT_ADD_ALL_DIGESTS, NULL); -#else +#else /* !defined(OPENSSL_1_1_API) */ ERR_load_crypto_strings(); OpenSSL_add_all_algorithms(); -#endif +#endif /* defined(OPENSSL_1_1_API) */ setup_openssl_threading(); @@ -278,8 +284,14 @@ log_engine(const char *fn, ENGINE *e) } #endif /* !defined(DISABLE_ENGINES) */ -/** Initialize engines for openssl (if enabled). */ -static void +/** Initialize engines for openssl (if enabled). Load all the built-in + * engines, along with the one called <b>accelName</b> (which may be NULL). + * If <b>accelName</b> is prefixed with "!", then it is required: return -1 + * if it can't be loaded. Otherwise return 0. + * + * If <b>accelDir</b> is not NULL, it is the path from which the engine should + * be loaded. */ +static int crypto_openssl_init_engines(const char *accelName, const char *accelDir) { @@ -287,7 +299,13 @@ crypto_openssl_init_engines(const char *accelName, (void)accelName; (void)accelDir; log_warn(LD_CRYPTO, "No OpenSSL hardware acceleration support enabled."); -#else + if (accelName && accelName[0] == '!') { + log_warn(LD_CRYPTO, "Unable to load required dynamic OpenSSL engine " + "\"%s\".", accelName+1); + return -1; + } + return 0; +#else /* !defined(DISABLE_ENGINES) */ ENGINE *e = NULL; log_info(LD_CRYPTO, "Initializing OpenSSL engine support."); @@ -295,6 +313,9 @@ crypto_openssl_init_engines(const char *accelName, ENGINE_register_all_complete(); if (accelName) { + const bool required = accelName[0] == '!'; + if (required) + ++accelName; if (accelDir) { log_info(LD_CRYPTO, "Trying to load dynamic OpenSSL engine \"%s\"" " via path \"%s\".", accelName, accelDir); @@ -305,8 +326,11 @@ crypto_openssl_init_engines(const char *accelName, e = ENGINE_by_id(accelName); } if (!e) { - log_warn(LD_CRYPTO, "Unable to load dynamic OpenSSL engine \"%s\".", + log_warn(LD_CRYPTO, "Unable to load %sdynamic OpenSSL engine \"%s\".", + required?"required ":"", accelName); + if (required) + return -1; } else { log_info(LD_CRYPTO, "Loaded dynamic OpenSSL engine \"%s\".", accelName); @@ -343,6 +367,7 @@ crypto_openssl_init_engines(const char *accelName, #ifdef NID_aes_256_gcm log_engine("AES-256-GCM", ENGINE_get_cipher_engine(NID_aes_256_gcm)); #endif + return 0; #endif /* defined(DISABLE_ENGINES) */ } @@ -353,7 +378,8 @@ crypto_openssl_late_init(int useAccel, const char *accelName, const char *accelDir) { if (useAccel > 0) { - crypto_openssl_init_engines(accelName, accelDir); + if (crypto_openssl_init_engines(accelName, accelDir) < 0) + return -1; } else { log_info(LD_CRYPTO, "NOT using OpenSSL engine support."); } @@ -382,7 +408,7 @@ crypto_openssl_thread_cleanup(void) void crypto_openssl_global_cleanup(void) { - #ifndef OPENSSL_1_1_API +#ifndef OPENSSL_1_1_API EVP_cleanup(); #endif #ifndef NEW_THREAD_API diff --git a/src/lib/crypt_ops/crypto_openssl_mgt.h b/src/lib/crypt_ops/crypto_openssl_mgt.h index 8dbadfc9d2..c67ab6467c 100644 --- a/src/lib/crypt_ops/crypto_openssl_mgt.h +++ b/src/lib/crypt_ops/crypto_openssl_mgt.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -83,6 +83,6 @@ int crypto_openssl_late_init(int useAccel, const char *accelName, void crypto_openssl_thread_cleanup(void); void crypto_openssl_global_cleanup(void); -#endif /* ENABLE_OPENSSL */ +#endif /* defined(ENABLE_OPENSSL) */ #endif /* !defined(TOR_CRYPTO_OPENSSL_H) */ diff --git a/src/lib/crypt_ops/crypto_options.inc b/src/lib/crypt_ops/crypto_options.inc new file mode 100644 index 0000000000..5bee0daacd --- /dev/null +++ b/src/lib/crypt_ops/crypto_options.inc @@ -0,0 +1,19 @@ + +/** + * @file crypto_options.inc + * @brief Declare configuration options for the crypto_ops module. + **/ + +/** Holds configuration about our cryptography options. */ +BEGIN_CONF_STRUCT(crypto_options_t) + +/** Should we enable extra OpenSSL hardware acceleration (where available)? */ +CONF_VAR(HardwareAccel, BOOL, CFLG_IMMUTABLE, "0") + +/** Optional OpenSSL hardware-acceleration engine name */ +CONF_VAR(AccelName, STRING, CFLG_IMMUTABLE, NULL) + +/** Optional OpenSSL hardware-acceleration engine search directory. */ +CONF_VAR(AccelDir, FILENAME, CFLG_IMMUTABLE, NULL) + +END_CONF_STRUCT(crypto_options_t) diff --git a/src/lib/crypt_ops/crypto_options_st.h b/src/lib/crypt_ops/crypto_options_st.h new file mode 100644 index 0000000000..a453c451fe --- /dev/null +++ b/src/lib/crypt_ops/crypto_options_st.h @@ -0,0 +1,23 @@ +/* Copyright (c) 2001 Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * @file crypto_options_st.h + * @brief Header for lib/crypt_ops/crypto_options_st.c + **/ + +#ifndef TOR_LIB_CRYPT_OPS_CRYPTO_OPTIONS_ST_H +#define TOR_LIB_CRYPT_OPS_CRYPTO_OPTIONS_ST_H + +#include "lib/conf/confdecl.h" + +#define CONF_CONTEXT STRUCT +#include "lib/crypt_ops/crypto_options.inc" +#undef CONF_CONTEXT + +typedef struct crypto_options_t crypto_options_t; + +#endif /* !defined(TOR_LIB_CRYPT_OPS_CRYPTO_OPTIONS_ST_H) */ diff --git a/src/lib/crypt_ops/crypto_pwbox.c b/src/lib/crypt_ops/crypto_pwbox.c index a8db08f7b7..bfad27d9fc 100644 --- a/src/lib/crypt_ops/crypto_pwbox.c +++ b/src/lib/crypt_ops/crypto_pwbox.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2014-2019, The Tor Project, Inc. */ +/* Copyright (c) 2014-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_pwbox.h b/src/lib/crypt_ops/crypto_pwbox.h index 5a26889fb2..0a85b1230a 100644 --- a/src/lib/crypt_ops/crypto_pwbox.h +++ b/src/lib/crypt_ops/crypto_pwbox.h @@ -1,4 +1,4 @@ -/* Copyright (c) 2014-2019, The Tor Project, Inc. */ +/* Copyright (c) 2014-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_rand.c b/src/lib/crypt_ops/crypto_rand.c index 206929d6b3..ce6f21dbb4 100644 --- a/src/lib/crypt_ops/crypto_rand.c +++ b/src/lib/crypt_ops/crypto_rand.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -11,7 +11,6 @@ * number generators, and working with randomness. **/ -#ifndef CRYPTO_RAND_PRIVATE #define CRYPTO_RAND_PRIVATE #include "lib/crypt_ops/crypto_rand.h" @@ -37,17 +36,18 @@ #include "lib/defs/digest_sizes.h" #include "lib/crypt_ops/crypto_digest.h" +#include "lib/ctime/di_ops.h" #ifdef ENABLE_NSS #include "lib/crypt_ops/crypto_nss_mgt.h" #endif #ifdef ENABLE_OPENSSL -DISABLE_GCC_WARNING(redundant-decls) +DISABLE_GCC_WARNING("-Wredundant-decls") #include <openssl/rand.h> #include <openssl/sha.h> -ENABLE_GCC_WARNING(redundant-decls) -#endif +ENABLE_GCC_WARNING("-Wredundant-decls") +#endif /* defined(ENABLE_OPENSSL) */ #ifdef ENABLE_NSS #include <pk11pub.h> @@ -248,7 +248,7 @@ crypto_strongest_rand_fallback(uint8_t *out, size_t out_len) (void)out; (void)out_len; return -1; -#else /* !(defined(_WIN32)) */ +#else /* !defined(_WIN32) */ static const char *filenames[] = { "/dev/srandom", "/dev/urandom", "/dev/random", NULL }; @@ -315,7 +315,7 @@ crypto_strongest_rand_raw(uint8_t *out, size_t out_len) } } - if ((out_len < sanity_min_size) || !tor_mem_is_zero((char*)out, out_len)) + if ((out_len < sanity_min_size) || !safe_mem_is_zero((char*)out, out_len)) return 0; } @@ -419,7 +419,7 @@ crypto_seed_openssl_rng(void) else return -1; } -#endif +#endif /* defined(ENABLE_OPENSSL) */ #ifdef ENABLE_NSS /** @@ -442,7 +442,7 @@ crypto_seed_nss_rng(void) return load_entropy_ok ? 0 : -1; } -#endif +#endif /* defined(ENABLE_NSS) */ /** * Seed the RNG for any and all crypto libraries that we're using with bytes @@ -520,7 +520,7 @@ crypto_rand_unmocked(char *to, size_t n) #undef BUFLEN } -#else +#else /* !defined(ENABLE_NSS) */ int r = RAND_bytes((unsigned char*)to, (int)n); /* We consider a PRNG failure non-survivable. Let's assert so that we get a * stack trace about where it happened. @@ -530,111 +530,14 @@ crypto_rand_unmocked(char *to, size_t n) } /** - * Return a pseudorandom integer, chosen uniformly from the values - * between 0 and <b>max</b>-1 inclusive. <b>max</b> must be between 1 and - * INT_MAX+1, inclusive. + * Draw an unsigned 32-bit integer uniformly at random. */ -int -crypto_rand_int(unsigned int max) -{ - unsigned int val; - unsigned int cutoff; - tor_assert(max <= ((unsigned int)INT_MAX)+1); - tor_assert(max > 0); /* don't div by 0 */ - - /* We ignore any values that are >= 'cutoff,' to avoid biasing the - * distribution with clipping at the upper end of unsigned int's - * range. - */ - cutoff = UINT_MAX - (UINT_MAX%max); - while (1) { - crypto_rand((char*)&val, sizeof(val)); - if (val < cutoff) - return val % max; - } -} - -/** - * Return a pseudorandom integer, chosen uniformly from the values i such - * that min <= i < max. - * - * <b>min</b> MUST be in range [0, <b>max</b>). - * <b>max</b> MUST be in range (min, INT_MAX]. - **/ -int -crypto_rand_int_range(unsigned int min, unsigned int max) -{ - tor_assert(min < max); - tor_assert(max <= INT_MAX); - - /* The overflow is avoided here because crypto_rand_int() returns a value - * between 0 and (max - min) inclusive. */ - return min + crypto_rand_int(max - min); -} - -/** - * As crypto_rand_int_range, but supports uint64_t. - **/ -uint64_t -crypto_rand_uint64_range(uint64_t min, uint64_t max) +uint32_t +crypto_rand_u32(void) { - tor_assert(min < max); - return min + crypto_rand_uint64(max - min); -} - -/** - * As crypto_rand_int_range, but supports time_t. - **/ -time_t -crypto_rand_time_range(time_t min, time_t max) -{ - tor_assert(min < max); - return min + (time_t)crypto_rand_uint64(max - min); -} - -/** - * Return a pseudorandom 64-bit integer, chosen uniformly from the values - * between 0 and <b>max</b>-1 inclusive. - **/ -uint64_t -crypto_rand_uint64(uint64_t max) -{ - uint64_t val; - uint64_t cutoff; - tor_assert(max < UINT64_MAX); - tor_assert(max > 0); /* don't div by 0 */ - - /* We ignore any values that are >= 'cutoff,' to avoid biasing the - * distribution with clipping at the upper end of unsigned int's - * range. - */ - cutoff = UINT64_MAX - (UINT64_MAX%max); - while (1) { - crypto_rand((char*)&val, sizeof(val)); - if (val < cutoff) - return val % max; - } -} - -/** - * Return a pseudorandom double d, chosen uniformly from the range - * 0.0 <= d < 1.0. - **/ -double -crypto_rand_double(void) -{ - /* We just use an unsigned int here; we don't really care about getting - * more than 32 bits of resolution */ - unsigned int u; - crypto_rand((char*)&u, sizeof(u)); -#if SIZEOF_INT == 4 -#define UINT_MAX_AS_DOUBLE 4294967296.0 -#elif SIZEOF_INT == 8 -#define UINT_MAX_AS_DOUBLE 1.8446744073709552e+19 -#else -#error SIZEOF_INT is neither 4 nor 8 -#endif /* SIZEOF_INT == 4 || ... */ - return ((double)u) / UINT_MAX_AS_DOUBLE; + uint32_t rand; + crypto_rand((void*)&rand, sizeof(rand)); + return rand; } /** @@ -724,8 +627,6 @@ crypto_force_rand_ssleay(void) RAND_set_rand_method(default_method); return 1; } -#endif +#endif /* defined(ENABLE_OPENSSL) */ return 0; } - -#endif /* !defined(CRYPTO_RAND_PRIVATE) */ diff --git a/src/lib/crypt_ops/crypto_rand.h b/src/lib/crypt_ops/crypto_rand.h index 86fa20faa3..99aff5d4a9 100644 --- a/src/lib/crypt_ops/crypto_rand.h +++ b/src/lib/crypt_ops/crypto_rand.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -16,6 +16,7 @@ #include "lib/cc/compat_compiler.h" #include "lib/cc/torint.h" #include "lib/testsupport/testsupport.h" +#include "lib/malloc/malloc.h" /* random numbers */ int crypto_seed_rng(void) ATTR_WUR; @@ -24,9 +25,11 @@ void crypto_rand_unmocked(char *to, size_t n); void crypto_strongest_rand(uint8_t *out, size_t out_len); MOCK_DECL(void,crypto_strongest_rand_,(uint8_t *out, size_t out_len)); int crypto_rand_int(unsigned int max); +unsigned crypto_rand_uint(unsigned limit); int crypto_rand_int_range(unsigned int min, unsigned int max); uint64_t crypto_rand_uint64_range(uint64_t min, uint64_t max); time_t crypto_rand_time_range(time_t min, time_t max); +uint32_t crypto_rand_u32(void); uint64_t crypto_rand_uint64(uint64_t max); double crypto_rand_double(void); struct tor_weak_rng_t; @@ -40,6 +43,61 @@ void *smartlist_choose(const struct smartlist_t *sl); void smartlist_shuffle(struct smartlist_t *sl); int crypto_force_rand_ssleay(void); +/** + * A fast PRNG, for use when the PRNG provided by our crypto library isn't + * fast enough. This one _should_ be cryptographically strong, but + * has seen less auditing than the PRNGs in OpenSSL and NSS. Use with + * caution. + * + * Note that this object is NOT thread-safe. If you need a thread-safe + * prng, use crypto_rand(), or wrap this in a mutex. + **/ +typedef struct crypto_fast_rng_t crypto_fast_rng_t; +/** + * Number of bytes used to seed a crypto_rand_fast_t. + **/ +crypto_fast_rng_t *crypto_fast_rng_new(void); +#define CRYPTO_FAST_RNG_SEED_LEN 48 +crypto_fast_rng_t *crypto_fast_rng_new_from_seed(const uint8_t *seed); +void crypto_fast_rng_getbytes(crypto_fast_rng_t *rng, uint8_t *out, size_t n); +void crypto_fast_rng_free_(crypto_fast_rng_t *); +#define crypto_fast_rng_free(c) \ + FREE_AND_NULL(crypto_fast_rng_t, crypto_fast_rng_free_, (c)) + +unsigned crypto_fast_rng_get_uint(crypto_fast_rng_t *rng, unsigned limit); +uint64_t crypto_fast_rng_get_uint64(crypto_fast_rng_t *rng, uint64_t limit); +uint32_t crypto_fast_rng_get_u32(crypto_fast_rng_t *rng); +uint64_t crypto_fast_rng_uint64_range(crypto_fast_rng_t *rng, + uint64_t min, uint64_t max); +double crypto_fast_rng_get_double(crypto_fast_rng_t *rng); + +/** + * Using the fast_rng <b>rng</b>, yield true with probability + * 1/<b>n</b>. Otherwise yield false. + * + * <b>n</b> must not be zero. + **/ +#define crypto_fast_rng_one_in_n(rng, n) \ + (0 == (crypto_fast_rng_get_uint((rng), (n)))) + +crypto_fast_rng_t *get_thread_fast_rng(void); + +#ifdef CRYPTO_PRIVATE +/* These are only used from crypto_init.c */ +void destroy_thread_fast_rng(void); +void crypto_rand_fast_init(void); +void crypto_rand_fast_shutdown(void); +#endif /* defined(CRYPTO_PRIVATE) */ + +#if defined(TOR_UNIT_TESTS) +/* Used for white-box testing */ +size_t crypto_fast_rng_get_bytes_used_per_stream(void); +/* For deterministic prng implementations */ +void crypto_fast_rng_disable_reseed(crypto_fast_rng_t *rng); +/* To override the prng for testing. */ +crypto_fast_rng_t *crypto_replace_thread_fast_rng(crypto_fast_rng_t *rng); +#endif /* defined(TOR_UNIT_TESTS) */ + #ifdef CRYPTO_RAND_PRIVATE STATIC int crypto_strongest_rand_raw(uint8_t *out, size_t out_len); diff --git a/src/lib/crypt_ops/crypto_rand_fast.c b/src/lib/crypt_ops/crypto_rand_fast.c new file mode 100644 index 0000000000..172ea48bdb --- /dev/null +++ b/src/lib/crypt_ops/crypto_rand_fast.c @@ -0,0 +1,438 @@ +/* Copyright (c) 2001, Matej Pfajfar. + * Copyright (c) 2001-2004, Roger Dingledine. + * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. + * Copyright (c) 2007-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file crypto_rand_fast.c + * + * \brief A fast strong PRNG for use when our underlying cryptographic + * library's PRNG isn't fast enough. + **/ + +/* This library is currently implemented to use the same implementation + * technique as libottery, using AES-CTR-256 as our underlying stream cipher. + * It's backtracking-resistant immediately, and prediction-resistant after + * a while. + * + * Here's how it works: + * + * We generate pseudorandom bytes using AES-CTR-256. We generate BUFLEN bytes + * at a time. When we do this, we keep the first SEED_LEN bytes as the key + * and the IV for our next invocation of AES_CTR, and yield the remaining + * BUFLEN - SEED_LEN bytes to the user as they invoke the PRNG. As we yield + * bytes to the user, we clear them from the buffer. + * + * After we have refilled the buffer RESEED_AFTER times, we mix in an + * additional SEED_LEN bytes from our strong PRNG into the seed. + * + * If the user ever asks for a huge number of bytes at once, we pull SEED_LEN + * bytes from the PRNG and use them with our stream cipher to fill the user's + * request. + */ + +#define CRYPTO_PRIVATE + +#include "lib/crypt_ops/crypto_rand.h" +#include "lib/crypt_ops/crypto_cipher.h" +#include "lib/crypt_ops/crypto_digest.h" +#include "lib/crypt_ops/crypto_util.h" +#include "lib/intmath/cmp.h" +#include "lib/cc/ctassert.h" +#include "lib/malloc/map_anon.h" +#include "lib/thread/threads.h" + +#include "lib/log/util_bug.h" + +#ifdef HAVE_SYS_TYPES_H +#include <sys/types.h> +#endif +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif + +#include <string.h> + +#ifdef NOINHERIT_CAN_FAIL +#define CHECK_PID +#endif + +#ifdef CHECK_PID +#define PID_FIELD_LEN sizeof(pid_t) +#else +#define PID_FIELD_LEN 0 +#endif + +/* Alias for CRYPTO_FAST_RNG_SEED_LEN to make our code shorter. + */ +#define SEED_LEN (CRYPTO_FAST_RNG_SEED_LEN) + +/* The amount of space that we mmap for a crypto_fast_rng_t. + */ +#define MAPLEN 4096 + +/* The number of random bytes that we can yield to the user after each + * time we fill a crypto_fast_rng_t's buffer. + */ +#define BUFLEN (MAPLEN - 2*sizeof(uint16_t) - SEED_LEN - PID_FIELD_LEN) + +/* The number of buffer refills after which we should fetch more + * entropy from crypto_strongest_rand(). + */ +#define RESEED_AFTER 16 + +/* The length of the stream cipher key we will use for the PRNG, in bytes. + */ +#define KEY_LEN (CRYPTO_FAST_RNG_SEED_LEN - CIPHER_IV_LEN) +/* The length of the stream cipher key we will use for the PRNG, in bits. + */ +#define KEY_BITS (KEY_LEN * 8) + +/* Make sure that we have a key length we can actually use with AES. */ +CTASSERT(KEY_BITS == 128 || KEY_BITS == 192 || KEY_BITS == 256); + +struct crypto_fast_rng_t { + /** How many more fills does this buffer have before we should mix + * in the output of crypto_strongest_rand()? + * + * This value may be negative if unit tests are enabled. If so, it + * indicates that we should never mix in extra data from + * crypto_strongest_rand(). + */ + int16_t n_till_reseed; + /** How many bytes are remaining in cbuf_t.bytes? */ + uint16_t bytes_left; +#ifdef CHECK_PID + /** Which process owns this fast_rng? If this value is zero, we do not + * need to test the owner. */ + pid_t owner; +#endif + struct cbuf_t { + /** The seed (key and IV) that we will use the next time that we refill + * cbuf_t. */ + uint8_t seed[SEED_LEN]; + /** + * Bytes that we are yielding to the user. The next byte to be + * yielded is at bytes[BUFLEN-bytes_left]; all other bytes in this + * array are set to zero. + */ + uint8_t bytes[BUFLEN]; + } buf; +}; + +/* alignof(uint8_t) should be 1, so there shouldn't be any padding in cbuf_t. + */ +CTASSERT(sizeof(struct cbuf_t) == BUFLEN+SEED_LEN); +/* We're trying to fit all of the RNG state into a nice mmapable chunk. + */ +CTASSERT(sizeof(crypto_fast_rng_t) <= MAPLEN); + +/** + * Initialize and return a new fast PRNG, using a strong random seed. + * + * Note that this object is NOT thread-safe. If you need a thread-safe + * prng, use crypto_rand(), or wrap this in a mutex. + **/ +crypto_fast_rng_t * +crypto_fast_rng_new(void) +{ + uint8_t seed[SEED_LEN]; + crypto_strongest_rand(seed, sizeof(seed)); + crypto_fast_rng_t *result = crypto_fast_rng_new_from_seed(seed); + memwipe(seed, 0, sizeof(seed)); + return result; +} + +/** + * Initialize and return a new fast PRNG, using a seed value specified + * in <b>seed</b>. This value must be CRYPTO_FAST_RNG_SEED_LEN bytes + * long. + * + * Note that this object is NOT thread-safe. If you need a thread-safe + * prng, you should probably look at get_thread_fast_rng(). Alternatively, + * use crypto_rand(), wrap this in a mutex. + **/ +crypto_fast_rng_t * +crypto_fast_rng_new_from_seed(const uint8_t *seed) +{ + unsigned inherit = INHERIT_RES_KEEP; + /* We try to allocate this object as securely as we can, to avoid + * having it get dumped, swapped, or shared after fork. + */ + crypto_fast_rng_t *result = tor_mmap_anonymous(sizeof(*result), + ANONMAP_PRIVATE | ANONMAP_NOINHERIT, + &inherit); + memcpy(result->buf.seed, seed, SEED_LEN); + /* Causes an immediate refill once the user asks for data. */ + result->bytes_left = 0; + result->n_till_reseed = RESEED_AFTER; +#ifdef CHECK_PID + if (inherit == INHERIT_RES_KEEP) { + /* This value will neither be dropped nor zeroed after fork, so we need to + * check our pid to make sure we are not sharing it across a fork. This + * can be expensive if the pid value isn't cached, sadly. + */ + result->owner = getpid(); + } +#elif defined(_WIN32) + /* Windows can't fork(), so there's no need to noinherit. */ +#else + /* We decided above that noinherit would always do _something_. Assert here + * that we were correct. */ + tor_assertf(inherit != INHERIT_RES_KEEP, + "We failed to create a non-inheritable memory region, even " + "though we believed such a failure to be impossible! This is " + "probably a bug in Tor support for your platform; please report " + "it."); +#endif /* defined(CHECK_PID) || ... */ + return result; +} + +#ifdef TOR_UNIT_TESTS +/** + * Unit tests only: prevent a crypto_fast_rng_t from ever mixing in more + * entropy. + */ +void +crypto_fast_rng_disable_reseed(crypto_fast_rng_t *rng) +{ + rng->n_till_reseed = -1; +} +#endif /* defined(TOR_UNIT_TESTS) */ + +/** + * Helper: create a crypto_cipher_t object from SEED_LEN bytes of + * input. The first KEY_LEN bytes are used as the stream cipher's key, + * and the remaining CIPHER_IV_LEN bytes are used as its IV. + **/ +static inline crypto_cipher_t * +cipher_from_seed(const uint8_t *seed) +{ + return crypto_cipher_new_with_iv_and_bits(seed, seed+KEY_LEN, KEY_BITS); +} + +/** + * Helper: mix additional entropy into <b>rng</b> by using our XOF to mix the + * old value for the seed with some additional bytes from + * crypto_strongest_rand(). + **/ +static void +crypto_fast_rng_add_entopy(crypto_fast_rng_t *rng) +{ + crypto_xof_t *xof = crypto_xof_new(); + crypto_xof_add_bytes(xof, rng->buf.seed, SEED_LEN); + { + uint8_t seedbuf[SEED_LEN]; + crypto_strongest_rand(seedbuf, SEED_LEN); + crypto_xof_add_bytes(xof, seedbuf, SEED_LEN); + memwipe(seedbuf, 0, SEED_LEN); + } + crypto_xof_squeeze_bytes(xof, rng->buf.seed, SEED_LEN); + crypto_xof_free(xof); +} + +/** + * Helper: refill the seed bytes and output buffer of <b>rng</b>, using + * the input seed bytes as input (key and IV) for the stream cipher. + * + * If the n_till_reseed counter has reached zero, mix more random bytes into + * the seed before refilling the buffer. + **/ +static void +crypto_fast_rng_refill(crypto_fast_rng_t *rng) +{ + rng->n_till_reseed--; + if (rng->n_till_reseed == 0) { + /* It's time to reseed the RNG. */ + crypto_fast_rng_add_entopy(rng); + rng->n_till_reseed = RESEED_AFTER; + } else if (rng->n_till_reseed < 0) { +#ifdef TOR_UNIT_TESTS + /* Reseeding is disabled for testing; never do it on this prng. */ + rng->n_till_reseed = -1; +#else + /* If testing is disabled, this shouldn't be able to become negative. */ + tor_assert_unreached(); +#endif /* defined(TOR_UNIT_TESTS) */ + } + /* Now fill rng->buf with output from our stream cipher, initialized from + * that seed value. */ + crypto_cipher_t *c = cipher_from_seed(rng->buf.seed); + memset(&rng->buf, 0, sizeof(rng->buf)); + crypto_cipher_crypt_inplace(c, (char*)&rng->buf, sizeof(rng->buf)); + crypto_cipher_free(c); + + rng->bytes_left = sizeof(rng->buf.bytes); +} + +/** + * Release all storage held by <b>rng</b>. + **/ +void +crypto_fast_rng_free_(crypto_fast_rng_t *rng) +{ + if (!rng) + return; + memwipe(rng, 0, sizeof(*rng)); + tor_munmap_anonymous(rng, sizeof(*rng)); +} + +/** + * Helper: extract bytes from the PRNG, refilling it as necessary. Does not + * optimize the case when the user has asked for a huge output. + **/ +static void +crypto_fast_rng_getbytes_impl(crypto_fast_rng_t *rng, uint8_t *out, + const size_t n) +{ +#ifdef CHECK_PID + if (rng->owner) { + /* Note that we only need to do this check when we have owner set: that + * is, when our attempt to block inheriting failed, and the result was + * INHERIT_RES_KEEP. + * + * If the result was INHERIT_RES_DROP, then any attempt to access the rng + * memory after forking will crash. + * + * If the result was INHERIT_RES_ZERO, then forking will set the bytes_left + * and n_till_reseed fields to zero. This function will call + * crypto_fast_rng_refill(), which will in turn reseed the PRNG. + * + * So we only need to do this test in the case when mmap_anonymous() + * returned INHERIT_KEEP. We avoid doing it needlessly, since getpid() is + * often a system call, and that can be slow. + */ + tor_assert(rng->owner == getpid()); + } +#endif /* defined(CHECK_PID) */ + + size_t bytes_to_yield = n; + + while (bytes_to_yield) { + if (rng->bytes_left == 0) + crypto_fast_rng_refill(rng); + + const size_t to_copy = MIN(rng->bytes_left, bytes_to_yield); + + tor_assert(sizeof(rng->buf.bytes) >= rng->bytes_left); + uint8_t *copy_from = rng->buf.bytes + + (sizeof(rng->buf.bytes) - rng->bytes_left); + memcpy(out, copy_from, to_copy); + memset(copy_from, 0, to_copy); + + out += to_copy; + bytes_to_yield -= to_copy; + rng->bytes_left -= to_copy; + } +} + +/** + * Extract <b>n</b> bytes from <b>rng</b> into the buffer at <b>out</b>. + **/ +void +crypto_fast_rng_getbytes(crypto_fast_rng_t *rng, uint8_t *out, size_t n) +{ + if (PREDICT_UNLIKELY(n > BUFLEN)) { + /* The user has asked for a lot of output; generate it from a stream + * cipher seeded by the PRNG rather than by pulling it out of the PRNG + * directly. + */ + uint8_t seed[SEED_LEN]; + crypto_fast_rng_getbytes_impl(rng, seed, SEED_LEN); + crypto_cipher_t *c = cipher_from_seed(seed); + memset(out, 0, n); + crypto_cipher_crypt_inplace(c, (char*)out, n); + crypto_cipher_free(c); + memwipe(seed, 0, sizeof(seed)); + return; + } + + crypto_fast_rng_getbytes_impl(rng, out, n); +} + +#if defined(TOR_UNIT_TESTS) +/** for white-box testing: return the number of bytes that are returned from + * the user for each invocation of the stream cipher in this RNG. */ +size_t +crypto_fast_rng_get_bytes_used_per_stream(void) +{ + return BUFLEN; +} +#endif /* defined(TOR_UNIT_TESTS) */ + +/** + * Thread-local instance for our fast RNG. + **/ +static tor_threadlocal_t thread_rng; + +/** + * Return a per-thread fast RNG, initializing it if necessary. + * + * You do not need to free this yourself. + * + * It is NOT safe to share this value across threads. + **/ +crypto_fast_rng_t * +get_thread_fast_rng(void) +{ + crypto_fast_rng_t *rng = tor_threadlocal_get(&thread_rng); + + if (PREDICT_UNLIKELY(rng == NULL)) { + rng = crypto_fast_rng_new(); + tor_threadlocal_set(&thread_rng, rng); + } + + return rng; +} + +/** + * Used when a thread is exiting: free the per-thread fast RNG if needed. + * Invoked from the crypto subsystem's thread-cleanup code. + **/ +void +destroy_thread_fast_rng(void) +{ + crypto_fast_rng_t *rng = tor_threadlocal_get(&thread_rng); + if (!rng) + return; + crypto_fast_rng_free(rng); + tor_threadlocal_set(&thread_rng, NULL); +} + +#ifdef TOR_UNIT_TESTS +/** + * Replace the current thread's rng with <b>rng</b>. For use by the + * unit tests only. Returns the previous thread rng. + **/ +crypto_fast_rng_t * +crypto_replace_thread_fast_rng(crypto_fast_rng_t *rng) +{ + crypto_fast_rng_t *old_rng = tor_threadlocal_get(&thread_rng); + tor_threadlocal_set(&thread_rng, rng); + return old_rng; +} +#endif /* defined(TOR_UNIT_TESTS) */ + +/** + * Initialize the global thread-local key that will be used to keep track + * of per-thread fast RNG instances. Called from the crypto subsystem's + * initialization code. + **/ +void +crypto_rand_fast_init(void) +{ + tor_threadlocal_init(&thread_rng); +} + +/** + * Initialize the global thread-local key that will be used to keep track + * of per-thread fast RNG instances. Called from the crypto subsystem's + * shutdown code. + **/ +void +crypto_rand_fast_shutdown(void) +{ + destroy_thread_fast_rng(); + tor_threadlocal_destroy(&thread_rng); +} diff --git a/src/lib/crypt_ops/crypto_rand_numeric.c b/src/lib/crypt_ops/crypto_rand_numeric.c new file mode 100644 index 0000000000..b2516c4bdc --- /dev/null +++ b/src/lib/crypt_ops/crypto_rand_numeric.c @@ -0,0 +1,194 @@ +/** + * \file crypto_rand_numeric.c + * + * \brief Functions for retrieving uniformly distributed numbers + * from our PRNGs. + **/ + +#include "lib/crypt_ops/crypto_rand.h" +#include "lib/log/util_bug.h" + +/** + * Implementation macro: yields code that returns a uniform unbiased + * random number between 0 and limit. "type" is the type of the number to + * return; "maxval" is the largest possible value of "type"; and "fill_stmt" + * is a code snippet that fills an object named "val" with random bits. + **/ +#define IMPLEMENT_RAND_UNSIGNED(type, maxval, limit, fill_stmt) \ + do { \ + type val; \ + type cutoff; \ + tor_assert((limit) > 0); \ + \ + /* We ignore any values that are >= 'cutoff,' to avoid biasing */ \ + /* the distribution with clipping at the upper end of the type's */ \ + /* range. */ \ + cutoff = (maxval) - ((maxval)%(limit)); \ + while (1) { \ + fill_stmt; \ + if (val < cutoff) \ + return val % (limit); \ + } \ + } while (0) + +/** + * Return a pseudorandom integer chosen uniformly from the values between 0 + * and <b>limit</b>-1 inclusive. limit must be strictly greater than 0, and + * less than UINT_MAX. */ +unsigned +crypto_rand_uint(unsigned limit) +{ + tor_assert(limit < UINT_MAX); + IMPLEMENT_RAND_UNSIGNED(unsigned, UINT_MAX, limit, + crypto_rand((char*)&val, sizeof(val))); +} + +/** + * Return a pseudorandom integer, chosen uniformly from the values + * between 0 and <b>max</b>-1 inclusive. <b>max</b> must be between 1 and + * INT_MAX+1, inclusive. + */ +int +crypto_rand_int(unsigned int max) +{ + /* We can't use IMPLEMENT_RAND_UNSIGNED directly, since we're trying + * to return a signed type. Instead we make sure that the range is + * reasonable for a nonnegative int, use crypto_rand_uint(), and cast. + */ + tor_assert(max <= ((unsigned int)INT_MAX)+1); + + return (int)crypto_rand_uint(max); +} + +/** + * Return a pseudorandom integer, chosen uniformly from the values i such + * that min <= i < max. + * + * <b>min</b> MUST be in range [0, <b>max</b>). + * <b>max</b> MUST be in range (min, INT_MAX]. + **/ +int +crypto_rand_int_range(unsigned int min, unsigned int max) +{ + tor_assert(min < max); + tor_assert(max <= INT_MAX); + + /* The overflow is avoided here because crypto_rand_int() returns a value + * between 0 and (max - min) inclusive. */ + return min + crypto_rand_int(max - min); +} + +/** + * As crypto_rand_int_range, but supports uint64_t. + **/ +uint64_t +crypto_rand_uint64_range(uint64_t min, uint64_t max) +{ + tor_assert(min < max); + return min + crypto_rand_uint64(max - min); +} + +/** + * As crypto_rand_int_range, but supports time_t. + **/ +time_t +crypto_rand_time_range(time_t min, time_t max) +{ + tor_assert(min < max); + return min + (time_t)crypto_rand_uint64(max - min); +} + +/** + * Return a pseudorandom 64-bit integer, chosen uniformly from the values + * between 0 and <b>max</b>-1 inclusive. + **/ +uint64_t +crypto_rand_uint64(uint64_t max) +{ + tor_assert(max < UINT64_MAX); + IMPLEMENT_RAND_UNSIGNED(uint64_t, UINT64_MAX, max, + crypto_rand((char*)&val, sizeof(val))); +} + +#if SIZEOF_INT == 4 +#define UINT_MAX_AS_DOUBLE 4294967296.0 +#elif SIZEOF_INT == 8 +#define UINT_MAX_AS_DOUBLE 1.8446744073709552e+19 +#else +#error SIZEOF_INT is neither 4 nor 8 +#endif /* SIZEOF_INT == 4 || ... */ + +/** + * Return a pseudorandom double d, chosen uniformly from the range + * 0.0 <= d < 1.0. + **/ +double +crypto_rand_double(void) +{ + /* We just use an unsigned int here; we don't really care about getting + * more than 32 bits of resolution */ + unsigned int u; + crypto_rand((char*)&u, sizeof(u)); + return ((double)u) / UINT_MAX_AS_DOUBLE; +} + +/** + * As crypto_rand_uint, but extract the result from a crypto_fast_rng_t + */ +unsigned +crypto_fast_rng_get_uint(crypto_fast_rng_t *rng, unsigned limit) +{ + tor_assert(limit < UINT_MAX); + IMPLEMENT_RAND_UNSIGNED(unsigned, UINT_MAX, limit, + crypto_fast_rng_getbytes(rng, (void*)&val, sizeof(val))); +} + +/** + * As crypto_rand_uint64, but extract the result from a crypto_fast_rng_t. + */ +uint64_t +crypto_fast_rng_get_uint64(crypto_fast_rng_t *rng, uint64_t limit) +{ + tor_assert(limit < UINT64_MAX); + IMPLEMENT_RAND_UNSIGNED(uint64_t, UINT64_MAX, limit, + crypto_fast_rng_getbytes(rng, (void*)&val, sizeof(val))); +} + +/** + * As crypto_rand_u32, but extract the result from a crypto_fast_rng_t. + */ +uint32_t +crypto_fast_rng_get_u32(crypto_fast_rng_t *rng) +{ + uint32_t val; + crypto_fast_rng_getbytes(rng, (void*)&val, sizeof(val)); + return val; +} + +/** + * As crypto_rand_uint64_range(), but extract the result from a + * crypto_fast_rng_t. + */ +uint64_t +crypto_fast_rng_uint64_range(crypto_fast_rng_t *rng, + uint64_t min, uint64_t max) +{ + /* Handle corrupted input */ + if (BUG(min >= max)) { + return min; + } + + return min + crypto_fast_rng_get_uint64(rng, max - min); +} + +/** + * As crypto_rand_get_double() but extract the result from a crypto_fast_rng_t. + */ +double +crypto_fast_rng_get_double(crypto_fast_rng_t *rng) +{ + unsigned int u; + crypto_fast_rng_getbytes(rng, (void*)&u, sizeof(u)); + return ((double)u) / UINT_MAX_AS_DOUBLE; +} + diff --git a/src/lib/crypt_ops/crypto_rsa.c b/src/lib/crypt_ops/crypto_rsa.c index 8fd8a8aa7b..195e4bbaf9 100644 --- a/src/lib/crypt_ops/crypto_rsa.c +++ b/src/lib/crypt_ops/crypto_rsa.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -59,7 +59,7 @@ crypto_get_rsa_padding(int padding) default: tor_assert(0); return -1; // LCOV_EXCL_LINE } } -#endif +#endif /* defined(ENABLE_OPENSSL) */ /** Compare the public-key components of a and b. Return non-zero iff * a==b. A NULL key is considered to be distinct from all non-NULL diff --git a/src/lib/crypt_ops/crypto_rsa.h b/src/lib/crypt_ops/crypto_rsa.h index 6d9cc8d30e..ab2e9db80d 100644 --- a/src/lib/crypt_ops/crypto_rsa.h +++ b/src/lib/crypt_ops/crypto_rsa.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -122,7 +122,7 @@ struct rsa_st *crypto_pk_get_openssl_rsa_(crypto_pk_t *env); crypto_pk_t *crypto_new_pk_from_openssl_rsa_(struct rsa_st *rsa); MOCK_DECL(struct evp_pkey_st *, crypto_pk_get_openssl_evp_pkey_,( crypto_pk_t *env,int private)); -#endif +#endif /* defined(ENABLE_OPENSSL) */ #ifdef ENABLE_NSS struct SECKEYPublicKeyStr; @@ -132,7 +132,7 @@ const struct SECKEYPublicKeyStr *crypto_pk_get_nss_pubkey( const crypto_pk_t *key); const struct SECKEYPrivateKeyStr *crypto_pk_get_nss_privkey( const crypto_pk_t *key); -#endif +#endif /* defined(ENABLE_NSS) */ void crypto_pk_assign_public(crypto_pk_t *dest, const crypto_pk_t *src); void crypto_pk_assign_private(crypto_pk_t *dest, const crypto_pk_t *src); @@ -143,6 +143,6 @@ struct SECItemStr; STATIC int secitem_uint_cmp(const struct SECItemStr *a, const struct SECItemStr *b); #endif -#endif +#endif /* defined(TOR_UNIT_TESTS) */ -#endif +#endif /* !defined(TOR_CRYPTO_RSA_H) */ diff --git a/src/lib/crypt_ops/crypto_rsa_nss.c b/src/lib/crypt_ops/crypto_rsa_nss.c index 7abf6716f0..66f325e868 100644 --- a/src/lib/crypt_ops/crypto_rsa_nss.c +++ b/src/lib/crypt_ops/crypto_rsa_nss.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -156,7 +156,7 @@ crypto_pk_get_openssl_evp_pkey_,(crypto_pk_t *pk, int private)) tor_free(buf); return result; } -#endif +#endif /* defined(ENABLE_OPENSSL) */ /** Allocate and return storage for a public key. The key itself will not yet * be set. @@ -645,7 +645,7 @@ crypto_pk_asn1_decode(const char *str, size_t len) return result; } -DISABLE_GCC_WARNING(unused-parameter) +DISABLE_GCC_WARNING("-Wunused-parameter") /** Given a crypto_pk_t <b>pk</b>, allocate a new buffer containing the Base64 * encoding of the DER representation of the private key into the diff --git a/src/lib/crypt_ops/crypto_rsa_openssl.c b/src/lib/crypt_ops/crypto_rsa_openssl.c index 17eae24cc2..c96ee81fd3 100644 --- a/src/lib/crypt_ops/crypto_rsa_openssl.c +++ b/src/lib/crypt_ops/crypto_rsa_openssl.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -16,7 +16,7 @@ #include "lib/log/util_bug.h" #include "lib/fs/files.h" -DISABLE_GCC_WARNING(redundant-decls) +DISABLE_GCC_WARNING("-Wredundant-decls") #include <openssl/err.h> #include <openssl/rsa.h> @@ -27,7 +27,7 @@ DISABLE_GCC_WARNING(redundant-decls) #include <openssl/bn.h> #include <openssl/conf.h> -ENABLE_GCC_WARNING(redundant-decls) +ENABLE_GCC_WARNING("-Wredundant-decls") #include "lib/log/log.h" #include "lib/encoding/binascii.h" @@ -54,7 +54,7 @@ crypto_pk_key_is_private(const crypto_pk_t *k) const BIGNUM *p, *q; RSA_get0_factors(k->key, &p, &q); return p != NULL; /* XXX/yawning: Should we check q? */ -#else /* !(defined(OPENSSL_1_1_API)) */ +#else /* !defined(OPENSSL_1_1_API) */ return k && k->key && k->key->p; #endif /* defined(OPENSSL_1_1_API) */ } @@ -288,7 +288,7 @@ crypto_pk_num_bits(crypto_pk_t *env) tor_assert(n != NULL); return RSA_bits(env->key); -#else /* !(defined(OPENSSL_1_1_API)) */ +#else /* !defined(OPENSSL_1_1_API) */ tor_assert(env->key->n); return BN_num_bits(env->key->n); #endif /* defined(OPENSSL_1_1_API) */ @@ -583,15 +583,15 @@ rsa_private_key_too_long(RSA *rsa, int max_bits) dmp1 = RSA_get0_dmp1(rsa); dmq1 = RSA_get0_dmq1(rsa); iqmp = RSA_get0_iqmp(rsa); -#else +#else /* !(OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,1,1)) */ /* The accessors above did not exist in openssl 1.1.0. */ p = q = dmp1 = dmq1 = iqmp = NULL; RSA_get0_key(rsa, &n, &e, &d); -#endif +#endif /* OPENSSL_VERSION_NUMBER >= OPENSSL_V_SERIES(1,1,1) */ if (RSA_bits(rsa) > max_bits) return true; -#else +#else /* !defined(OPENSSL_1_1_API) */ n = rsa->n; e = rsa->e; p = rsa->p; @@ -600,7 +600,7 @@ rsa_private_key_too_long(RSA *rsa, int max_bits) dmp1 = rsa->dmp1; dmq1 = rsa->dmq1; iqmp = rsa->iqmp; -#endif +#endif /* defined(OPENSSL_1_1_API) */ if (n && BN_num_bits(n) > max_bits) return true; diff --git a/src/lib/crypt_ops/crypto_s2k.c b/src/lib/crypt_ops/crypto_s2k.c index 42276597d4..3a9ed5ef58 100644 --- a/src/lib/crypt_ops/crypto_s2k.c +++ b/src/lib/crypt_ops/crypto_s2k.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -285,7 +285,7 @@ secret_to_key_compute_key(uint8_t *key_out, size_t key_out_len, if (rv < 0) return S2K_FAILED; return (int)key_out_len; -#else +#else /* !defined(ENABLE_OPENSSL) */ SECItem passItem = { .type = siBuffer, .data = (unsigned char *) secret, .len = (int)secret_len }; @@ -325,7 +325,7 @@ secret_to_key_compute_key(uint8_t *key_out, size_t key_out_len, if (alg) SECOID_DestroyAlgorithmID(alg, PR_TRUE); return rv; -#endif +#endif /* defined(ENABLE_OPENSSL) */ } case S2K_TYPE_SCRYPT: { @@ -348,7 +348,7 @@ secret_to_key_compute_key(uint8_t *key_out, size_t key_out_len, if (rv != 0) return S2K_FAILED; return (int)key_out_len; -#else /* !(defined(HAVE_SCRYPT)) */ +#else /* !defined(HAVE_SCRYPT) */ return S2K_NO_SCRYPT_SUPPORT; #endif /* defined(HAVE_SCRYPT) */ } @@ -380,7 +380,7 @@ secret_to_key_derivekey(uint8_t *key_out, size_t key_out_len, #ifndef HAVE_SCRYPT if (type == S2K_TYPE_SCRYPT) return S2K_NO_SCRYPT_SUPPORT; - #endif +#endif if (! legacy_format) { ++spec; diff --git a/src/lib/crypt_ops/crypto_s2k.h b/src/lib/crypt_ops/crypto_s2k.h index a16a3d781e..181a17acb1 100644 --- a/src/lib/crypt_ops/crypto_s2k.h +++ b/src/lib/crypt_ops/crypto_s2k.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** diff --git a/src/lib/crypt_ops/crypto_sys.h b/src/lib/crypt_ops/crypto_sys.h new file mode 100644 index 0000000000..2115d4fc99 --- /dev/null +++ b/src/lib/crypt_ops/crypto_sys.h @@ -0,0 +1,14 @@ +/* Copyright (c) 2018-2020, The Tor Project, Inc. */ +/* See LICENSE for licensing information */ + +/** + * \file crypto_sys.h + * \brief Declare subsystem object for the crypto module. + **/ + +#ifndef TOR_CRYPTO_SYS_H +#define TOR_CRYPTO_SYS_H + +extern const struct subsys_fns_t sys_crypto; + +#endif /* !defined(TOR_CRYPTO_SYS_H) */ diff --git a/src/lib/crypt_ops/crypto_util.c b/src/lib/crypt_ops/crypto_util.c index 67a1a9eb92..7ebb860d09 100644 --- a/src/lib/crypt_ops/crypto_util.c +++ b/src/lib/crypt_ops/crypto_util.c @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -10,8 +10,6 @@ * \brief Common cryptographic utilities. **/ -#define CRYPTO_UTIL_PRIVATE - #include "lib/crypt_ops/crypto_util.h" #include "lib/cc/compat_compiler.h" @@ -26,11 +24,11 @@ #include <stdlib.h> #ifdef ENABLE_OPENSSL -DISABLE_GCC_WARNING(redundant-decls) +DISABLE_GCC_WARNING("-Wredundant-decls") #include <openssl/err.h> #include <openssl/crypto.h> -ENABLE_GCC_WARNING(redundant-decls) -#endif +ENABLE_GCC_WARNING("-Wredundant-decls") +#endif /* defined(ENABLE_OPENSSL) */ #include "lib/log/log.h" #include "lib/log/util_bug.h" @@ -109,3 +107,17 @@ memwipe(void *mem, uint8_t byte, size_t sz) **/ memset(mem, byte, sz); } + +/** + * Securely all memory in <b>str</b>, then free it. + * + * As tor_free(), tolerates null pointers. + **/ +void +tor_str_wipe_and_free_(char *str) +{ + if (!str) + return; + memwipe(str, 0, strlen(str)); + tor_free_(str); +} diff --git a/src/lib/crypt_ops/crypto_util.h b/src/lib/crypt_ops/crypto_util.h index 613a1bd0dd..36ee230176 100644 --- a/src/lib/crypt_ops/crypto_util.h +++ b/src/lib/crypt_ops/crypto_util.h @@ -1,7 +1,7 @@ /* Copyright (c) 2001, Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2019, The Tor Project, Inc. */ + * Copyright (c) 2007-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -14,8 +14,18 @@ #define TOR_CRYPTO_UTIL_H #include "lib/cc/torint.h" +#include "lib/malloc/malloc.h" /** OpenSSL-based utility functions. */ void memwipe(void *mem, uint8_t byte, size_t sz); +void tor_str_wipe_and_free_(char *str); +/** + * Securely all memory in <b>str</b>, then free it. + * + * As tor_free(), tolerates null pointers, and sets <b>str</b> to NULL. + **/ +#define tor_str_wipe_and_free(str) \ + FREE_AND_NULL(char, tor_str_wipe_and_free_, (str)) + #endif /* !defined(TOR_CRYPTO_UTIL_H) */ diff --git a/src/lib/crypt_ops/digestset.c b/src/lib/crypt_ops/digestset.c index 0dba64d595..5162d6d8bd 100644 --- a/src/lib/crypt_ops/digestset.c +++ b/src/lib/crypt_ops/digestset.c @@ -1,4 +1,4 @@ -/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* Copyright (c) 2018-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -11,7 +11,7 @@ #include "lib/crypt_ops/crypto_rand.h" #include "lib/defs/digest_sizes.h" #include "lib/crypt_ops/digestset.h" -#include "siphash.h" +#include "ext/siphash.h" /* Wrap our hash function to have the signature that the bloom filter * needs. */ diff --git a/src/lib/crypt_ops/digestset.h b/src/lib/crypt_ops/digestset.h index 91d53a0542..505ac10395 100644 --- a/src/lib/crypt_ops/digestset.h +++ b/src/lib/crypt_ops/digestset.h @@ -1,4 +1,4 @@ -/* Copyright (c) 2018-2019, The Tor Project, Inc. */ +/* Copyright (c) 2018-2020, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** @@ -26,4 +26,4 @@ void digestset_add(digestset_t *set, const char *addr); int digestset_probably_contains(const digestset_t *set, const char *addr); -#endif +#endif /* !defined(TOR_DIGESTSET_H) */ diff --git a/src/lib/crypt_ops/include.am b/src/lib/crypt_ops/include.am index 1022096fdc..7644cab412 100644 --- a/src/lib/crypt_ops/include.am +++ b/src/lib/crypt_ops/include.am @@ -5,6 +5,7 @@ if UNITTESTS_ENABLED noinst_LIBRARIES += src/lib/libtor-crypt-ops-testing.a endif +# ADD_C_FILE: INSERT SOURCES HERE. src_lib_libtor_crypt_ops_a_SOURCES = \ src/lib/crypt_ops/crypto_cipher.c \ src/lib/crypt_ops/crypto_curve25519.c \ @@ -17,6 +18,8 @@ src_lib_libtor_crypt_ops_a_SOURCES = \ src/lib/crypt_ops/crypto_ope.c \ src/lib/crypt_ops/crypto_pwbox.c \ src/lib/crypt_ops/crypto_rand.c \ + src/lib/crypt_ops/crypto_rand_fast.c \ + src/lib/crypt_ops/crypto_rand_numeric.c \ src/lib/crypt_ops/crypto_rsa.c \ src/lib/crypt_ops/crypto_s2k.c \ src/lib/crypt_ops/crypto_util.c \ @@ -25,12 +28,14 @@ src_lib_libtor_crypt_ops_a_SOURCES = \ if USE_NSS src_lib_libtor_crypt_ops_a_SOURCES += \ src/lib/crypt_ops/aes_nss.c \ + src/lib/crypt_ops/crypto_digest_nss.c \ src/lib/crypt_ops/crypto_dh_nss.c \ src/lib/crypt_ops/crypto_nss_mgt.c \ src/lib/crypt_ops/crypto_rsa_nss.c else src_lib_libtor_crypt_ops_a_SOURCES += \ src/lib/crypt_ops/aes_openssl.c \ + src/lib/crypt_ops/crypto_digest_openssl.c \ src/lib/crypt_ops/crypto_rsa_openssl.c endif @@ -48,6 +53,7 @@ src_lib_libtor_crypt_ops_testing_a_CPPFLAGS = $(AM_CPPFLAGS) $(TEST_CPPFLAGS) src_lib_libtor_crypt_ops_testing_a_CFLAGS = \ $(AM_CFLAGS) $(TOR_CFLAGS_CRYPTLIB) $(TEST_CFLAGS) +# ADD_C_FILE: INSERT HEADERS HERE. noinst_HEADERS += \ src/lib/crypt_ops/aes.h \ src/lib/crypt_ops/compat_openssl.h \ @@ -62,9 +68,12 @@ noinst_HEADERS += \ src/lib/crypt_ops/crypto_nss_mgt.h \ src/lib/crypt_ops/crypto_openssl_mgt.h \ src/lib/crypt_ops/crypto_ope.h \ + src/lib/crypt_ops/crypto_options.inc \ + src/lib/crypt_ops/crypto_options_st.h \ src/lib/crypt_ops/crypto_pwbox.h \ src/lib/crypt_ops/crypto_rand.h \ src/lib/crypt_ops/crypto_rsa.h \ src/lib/crypt_ops/crypto_s2k.h \ + src/lib/crypt_ops/crypto_sys.h \ src/lib/crypt_ops/crypto_util.h \ src/lib/crypt_ops/digestset.h diff --git a/src/lib/crypt_ops/lib_crypt_ops.md b/src/lib/crypt_ops/lib_crypt_ops.md new file mode 100644 index 0000000000..4e675e4871 --- /dev/null +++ b/src/lib/crypt_ops/lib_crypt_ops.md @@ -0,0 +1,137 @@ +@dir /lib/crypt_ops +@brief lib/crypt_ops: Cryptographic operations. + +This module contains wrappers around the cryptographic libraries that we +support, and implementations for some higher-level cryptographic +constructions that we use. + +It wraps our two major cryptographic backends (OpenSSL or NSS, as configured +by the user), and also wraps other cryptographic code in src/ext. + +Generally speaking, Tor code shouldn't be calling OpenSSL or NSS +(or any other crypto library) directly. Instead, we should indirect through +one of the functions in this directory, or through \refdir{lib/tls}. + +Cryptography functionality that's available is described below. + +### RNG facilities ### + +The most basic RNG capability in Tor is the crypto_rand() family of +functions. These currently use OpenSSL's RAND_() backend, but may use +something faster in the future. + +In addition to crypto_rand(), which fills in a buffer with random +bytes, we also have functions to produce random integers in certain +ranges; to produce random hostnames; to produce random doubles, etc. + +When you're creating a long-term cryptographic secret, you might want +to use crypto_strongest_rand() instead of crypto_rand(). It takes the +operating system's entropy source and combines it with output from +crypto_rand(). This is a pure paranoia measure, but it might help us +someday. + +You can use smartlist_choose() to pick a random element from a smartlist +and smartlist_shuffle() to randomize the order of a smartlist. Both are +potentially a bit slow. + +### Cryptographic digests and related functions ### + +We treat digests as separate types based on the length of their +outputs. We support one 160-bit digest (SHA1), two 256-bit digests +(SHA256 and SHA3-256), and two 512-bit digests (SHA512 and SHA3-512). + +You should not use SHA1 for anything new. + +The crypto_digest\*() family of functions manipulates digests. You +can either compute a digest of a chunk of memory all at once using +crypto_digest(), crypto_digest256(), or crypto_digest512(). Or you +can create a crypto_digest_t object with +crypto_digest{,256,512}_new(), feed information to it in chunks using +crypto_digest_add_bytes(), and then extract the final digest using +crypto_digest_get_digest(). You can copy the state of one of these +objects using crypto_digest_dup() or crypto_digest_assign(). + +We support the HMAC hash-based message authentication code +instantiated using SHA256. See crypto_hmac_sha256. (You should not +add any HMAC users with SHA1, and HMAC is not necessary with SHA3.) + +We also support the SHA3 cousins, SHAKE128 and SHAKE256. Unlike +digests, these are extendable output functions (or XOFs) where you can +get any amount of output. Use the crypto_xof_\*() functions to access +these. + +We have several ways to derive keys from cryptographically strong secret +inputs (like diffie-hellman outputs). The old +crypto_expand_key_material_TAP() performs an ad-hoc KDF based on SHA1 -- you +shouldn't use it for implementing anything but old versions of the Tor +protocol. You can use HKDF-SHA256 (as defined in RFC5869) for more modern +protocols. Also consider SHAKE256. + +If your input is potentially weak, like a password or passphrase, use a salt +along with the secret_to_key() functions as defined in crypto_s2k.c. Prefer +scrypt over other hashing methods when possible. If you're using a password +to encrypt something, see the "boxed file storage" section below. + +Finally, in order to store objects in hash tables, Tor includes the +randomized SipHash 2-4 function. Call it via the siphash24g() function in +src/ext/siphash.h whenever you're creating a hashtable whose keys may be +manipulated by an attacker in order to DoS you with collisions. + + +### Stream ciphers ### + +You can create instances of a stream cipher using crypto_cipher_new(). +These are stateful objects of type crypto_cipher_t. Note that these +objects only support AES-128 right now; a future version should add +support for AES-128 and/or ChaCha20. + +You can encrypt/decrypt with crypto_cipher_encrypt or +crypto_cipher_decrypt. The crypto_cipher_crypt_inplace function performs +an encryption without a copy. + +Note that sensible people should not use raw stream ciphers; they should +probably be using some kind of AEAD. Sorry. + +### Public key functionality ### + +We support four public key algorithms: DH1024, RSA, Curve25519, and +Ed25519. + +We support DH1024 over two prime groups. You access these via the +crypto_dh_\*() family of functions. + +We support RSA in many bit sizes for signing and encryption. You access +it via the crypto_pk_*() family of functions. Note that a crypto_pk_t +may or may not include a private key. See the crypto_pk_* functions in +crypto.c for a full list of functions here. + +For Curve25519 functionality, see the functions and types in +crypto_curve25519.c. Curve25519 is generally suitable for when you need +a secure fast elliptic-curve diffie hellman implementation. When +designing new protocols, prefer it over DH in Z_p. + +For Ed25519 functionality, see the functions and types in +crypto_ed25519.c. Ed25519 is a generally suitable as a secure fast +elliptic curve signature method. For new protocols, prefer it over RSA +signatures. + +### Metaformats for storage ### + +When OpenSSL manages the storage of some object, we use whatever format +OpenSSL provides -- typically, some kind of PEM-wrapped base 64 encoding +that starts with "----- BEGIN CRYPTOGRAPHIC OBJECT ----". + +When we manage the storage of some cryptographic object, we prefix the +object with 32-byte NUL-padded prefix in order to avoid accidental +object confusion; see the crypto_read_tagged_contents_from_file() and +crypto_write_tagged_contents_to_file() functions for manipulating +these. The prefix is "== type: tag ==", where type describes the object +and its encoding, and tag indicates which one it is. + +### Boxed-file storage ### + +When managing keys, you frequently want to have some way to write a +secret object to disk, encrypted with a passphrase. The crypto_pwbox +and crypto_unpwbox functions do so in a way that's likely to be +readable by future versions of Tor. + |