diff options
Diffstat (limited to 'src/lib/crypt_ops/crypto_rsa.c')
| -rw-r--r-- | src/lib/crypt_ops/crypto_rsa.c | 1001 |
1 files changed, 239 insertions, 762 deletions
diff --git a/src/lib/crypt_ops/crypto_rsa.c b/src/lib/crypt_ops/crypto_rsa.c index 5ec69d7319..6a9e2948f1 100644 --- a/src/lib/crypt_ops/crypto_rsa.c +++ b/src/lib/crypt_ops/crypto_rsa.c @@ -9,7 +9,7 @@ * \brief Block of functions related with RSA utilities and operations. **/ -#include "lib/crypt_ops/crypto.h" +#include "lib/crypt_ops/crypto_cipher.h" #include "lib/crypt_ops/crypto_curve25519.h" #include "lib/crypt_ops/crypto_digest.h" #include "lib/crypt_ops/crypto_format.h" @@ -21,32 +21,14 @@ #include "lib/log/util_bug.h" #include "lib/fs/files.h" -DISABLE_GCC_WARNING(redundant-decls) - -#include <openssl/err.h> -#include <openssl/rsa.h> -#include <openssl/pem.h> -#include <openssl/evp.h> -#include <openssl/engine.h> -#include <openssl/rand.h> -#include <openssl/bn.h> -#include <openssl/dh.h> -#include <openssl/conf.h> -#include <openssl/hmac.h> - -ENABLE_GCC_WARNING(redundant-decls) - #include "lib/log/log.h" #include "lib/encoding/binascii.h" +#include "lib/encoding/pem.h" #include <string.h> - -/** Declaration for crypto_pk_t structure. */ -struct crypto_pk_t -{ - int refs; /**< reference count, so we don't have to copy keys */ - RSA *key; /**< The key itself */ -}; +#ifdef HAVE_SYS_STAT_H +#include <sys/stat.h> +#endif /** Return the number of bytes added by padding method <b>padding</b>. */ @@ -55,11 +37,12 @@ crypto_get_rsa_padding_overhead(int padding) { switch (padding) { - case RSA_PKCS1_OAEP_PADDING: return PKCS1_OAEP_PADDING_OVERHEAD; + case PK_PKCS1_OAEP_PADDING: return PKCS1_OAEP_PADDING_OVERHEAD; default: tor_assert(0); return -1; // LCOV_EXCL_LINE } } +#ifdef ENABLE_OPENSSL /** Given a padding method <b>padding</b>, return the correct OpenSSL constant. */ int @@ -71,442 +54,7 @@ crypto_get_rsa_padding(int padding) default: tor_assert(0); return -1; // LCOV_EXCL_LINE } } - -/** used internally: quicly validate a crypto_pk_t object as a private key. - * Return 1 iff the public key is valid, 0 if obviously invalid. - */ -static int -crypto_pk_private_ok(const crypto_pk_t *k) -{ -#ifdef OPENSSL_1_1_API - if (!k || !k->key) - return 0; - - 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)) */ - return k && k->key && k->key->p; -#endif /* defined(OPENSSL_1_1_API) */ -} - -/** used by tortls.c: wrap an RSA* in a crypto_pk_t. */ -crypto_pk_t * -crypto_new_pk_from_rsa_(RSA *rsa) -{ - crypto_pk_t *env; - tor_assert(rsa); - env = tor_malloc(sizeof(crypto_pk_t)); - env->refs = 1; - env->key = rsa; - return env; -} - -/** Helper, used by tor-gencert.c. Return the RSA from a - * crypto_pk_t. */ -RSA * -crypto_pk_get_rsa_(crypto_pk_t *env) -{ - return env->key; -} - -/** used by tortls.c: get an equivalent EVP_PKEY* for a crypto_pk_t. Iff - * private is set, include the private-key portion of the key. Return a valid - * pointer on success, and NULL on failure. */ -MOCK_IMPL(EVP_PKEY *, -crypto_pk_get_evp_pkey_,(crypto_pk_t *env, int private)) -{ - RSA *key = NULL; - EVP_PKEY *pkey = NULL; - tor_assert(env->key); - if (private) { - if (!(key = RSAPrivateKey_dup(env->key))) - goto error; - } else { - if (!(key = RSAPublicKey_dup(env->key))) - goto error; - } - if (!(pkey = EVP_PKEY_new())) - goto error; - if (!(EVP_PKEY_assign_RSA(pkey, key))) - goto error; - return pkey; - error: - if (pkey) - EVP_PKEY_free(pkey); - if (key) - RSA_free(key); - return NULL; -} - -/** Allocate and return storage for a public key. The key itself will not yet - * be set. - */ -MOCK_IMPL(crypto_pk_t *, -crypto_pk_new,(void)) -{ - RSA *rsa; - - rsa = RSA_new(); - tor_assert(rsa); - return crypto_new_pk_from_rsa_(rsa); -} - -/** Release a reference to an asymmetric key; when all the references - * are released, free the key. - */ -void -crypto_pk_free_(crypto_pk_t *env) -{ - if (!env) - return; - - if (--env->refs > 0) - return; - tor_assert(env->refs == 0); - - if (env->key) - RSA_free(env->key); - - tor_free(env); -} - -/** Generate a <b>bits</b>-bit new public/private keypair in <b>env</b>. - * Return 0 on success, -1 on failure. - */ -MOCK_IMPL(int, -crypto_pk_generate_key_with_bits,(crypto_pk_t *env, int bits)) -{ - tor_assert(env); - - if (env->key) { - RSA_free(env->key); - env->key = NULL; - } - - { - BIGNUM *e = BN_new(); - RSA *r = NULL; - if (!e) - goto done; - if (! BN_set_word(e, 65537)) - goto done; - r = RSA_new(); - if (!r) - goto done; - if (RSA_generate_key_ex(r, bits, e, NULL) == -1) - goto done; - - env->key = r; - r = NULL; - done: - if (e) - BN_clear_free(e); - if (r) - RSA_free(r); - } - - if (!env->key) { - crypto_log_errors(LOG_WARN, "generating RSA key"); - return -1; - } - - return 0; -} - -/** A PEM callback that always reports a failure to get a password */ -static int -pem_no_password_cb(char *buf, int size, int rwflag, void *u) -{ - (void)buf; - (void)size; - (void)rwflag; - (void)u; - return -1; -} - -/** Read a PEM-encoded private key from the <b>len</b>-byte string <b>s</b> - * into <b>env</b>. Return 0 on success, -1 on failure. If len is -1, - * the string is nul-terminated. - */ -int -crypto_pk_read_private_key_from_string(crypto_pk_t *env, - const char *s, ssize_t len) -{ - BIO *b; - - tor_assert(env); - tor_assert(s); - tor_assert(len < INT_MAX && len < SSIZE_T_CEILING); - - /* Create a read-only memory BIO, backed by the string 's' */ - b = BIO_new_mem_buf((char*)s, (int)len); - if (!b) - return -1; - - if (env->key) - RSA_free(env->key); - - env->key = PEM_read_bio_RSAPrivateKey(b,NULL,pem_no_password_cb,NULL); - - BIO_free(b); - - if (!env->key) { - crypto_log_errors(LOG_WARN, "Error parsing private key"); - return -1; - } - return 0; -} - -/** Read a PEM-encoded private key from the file named by - * <b>keyfile</b> into <b>env</b>. Return 0 on success, -1 on failure. - */ -int -crypto_pk_read_private_key_from_filename(crypto_pk_t *env, - const char *keyfile) -{ - char *contents; - int r; - - /* Read the file into a string. */ - contents = read_file_to_str(keyfile, 0, NULL); - if (!contents) { - log_warn(LD_CRYPTO, "Error reading private key from \"%s\"", keyfile); - return -1; - } - - /* Try to parse it. */ - r = crypto_pk_read_private_key_from_string(env, contents, -1); - memwipe(contents, 0, strlen(contents)); - tor_free(contents); - if (r) - return -1; /* read_private_key_from_string already warned, so we don't.*/ - - /* Make sure it's valid. */ - if (crypto_pk_check_key(env) <= 0) - return -1; - - return 0; -} - -/** Helper function to implement crypto_pk_write_*_key_to_string. Return 0 on - * success, -1 on failure. */ -static int -crypto_pk_write_key_to_string_impl(crypto_pk_t *env, char **dest, - size_t *len, int is_public) -{ - BUF_MEM *buf; - BIO *b; - int r; - - tor_assert(env); - tor_assert(env->key); - tor_assert(dest); - - b = BIO_new(BIO_s_mem()); /* Create a memory BIO */ - if (!b) - return -1; - - /* Now you can treat b as if it were a file. Just use the - * PEM_*_bio_* functions instead of the non-bio variants. - */ - if (is_public) - r = PEM_write_bio_RSAPublicKey(b, env->key); - else - r = PEM_write_bio_RSAPrivateKey(b, env->key, NULL,NULL,0,NULL,NULL); - - if (!r) { - crypto_log_errors(LOG_WARN, "writing RSA key to string"); - BIO_free(b); - return -1; - } - - BIO_get_mem_ptr(b, &buf); - - *dest = tor_malloc(buf->length+1); - memcpy(*dest, buf->data, buf->length); - (*dest)[buf->length] = 0; /* nul terminate it */ - *len = buf->length; - - BIO_free(b); - - return 0; -} - -/** PEM-encode the public key portion of <b>env</b> and write it to a - * newly allocated string. On success, set *<b>dest</b> to the new - * string, *<b>len</b> to the string's length, and return 0. On - * failure, return -1. - */ -int -crypto_pk_write_public_key_to_string(crypto_pk_t *env, char **dest, - size_t *len) -{ - return crypto_pk_write_key_to_string_impl(env, dest, len, 1); -} - -/** PEM-encode the private key portion of <b>env</b> and write it to a - * newly allocated string. On success, set *<b>dest</b> to the new - * string, *<b>len</b> to the string's length, and return 0. On - * failure, return -1. - */ -int -crypto_pk_write_private_key_to_string(crypto_pk_t *env, char **dest, - size_t *len) -{ - return crypto_pk_write_key_to_string_impl(env, dest, len, 0); -} - -/** Read a PEM-encoded public key from the first <b>len</b> characters of - * <b>src</b>, and store the result in <b>env</b>. Return 0 on success, -1 on - * failure. - */ -int -crypto_pk_read_public_key_from_string(crypto_pk_t *env, const char *src, - size_t len) -{ - BIO *b; - - tor_assert(env); - tor_assert(src); - tor_assert(len<INT_MAX); - - b = BIO_new(BIO_s_mem()); /* Create a memory BIO */ - if (!b) - return -1; - - BIO_write(b, src, (int)len); - - if (env->key) - RSA_free(env->key); - env->key = PEM_read_bio_RSAPublicKey(b, NULL, pem_no_password_cb, NULL); - BIO_free(b); - if (!env->key) { - crypto_log_errors(LOG_WARN, "reading public key from string"); - return -1; - } - - return 0; -} - -/** Write the private key from <b>env</b> into the file named by <b>fname</b>, - * PEM-encoded. Return 0 on success, -1 on failure. - */ -int -crypto_pk_write_private_key_to_filename(crypto_pk_t *env, - const char *fname) -{ - BIO *bio; - char *cp; - long len; - char *s; - int r; - - tor_assert(crypto_pk_private_ok(env)); - - if (!(bio = BIO_new(BIO_s_mem()))) - return -1; - if (PEM_write_bio_RSAPrivateKey(bio, env->key, NULL,NULL,0,NULL,NULL) - == 0) { - crypto_log_errors(LOG_WARN, "writing private key"); - BIO_free(bio); - return -1; - } - len = BIO_get_mem_data(bio, &cp); - tor_assert(len >= 0); - s = tor_malloc(len+1); - memcpy(s, cp, len); - s[len]='\0'; - r = write_str_to_file(fname, s, 0); - BIO_free(bio); - memwipe(s, 0, strlen(s)); - tor_free(s); - return r; -} - -/** Return true iff <b>env</b> has a valid key. - */ -int -crypto_pk_check_key(crypto_pk_t *env) -{ - int r; - tor_assert(env); - - r = RSA_check_key(env->key); - if (r <= 0) - crypto_log_errors(LOG_WARN,"checking RSA key"); - return r; -} - -/** Return true iff <b>key</b> contains the private-key portion of the RSA - * key. */ -int -crypto_pk_key_is_private(const crypto_pk_t *key) -{ - tor_assert(key); - return crypto_pk_private_ok(key); -} - -/** Return true iff <b>env</b> contains a public key whose public exponent - * equals 65537. - */ -int -crypto_pk_public_exponent_ok(crypto_pk_t *env) -{ - tor_assert(env); - tor_assert(env->key); - - const BIGNUM *e; - -#ifdef OPENSSL_1_1_API - const BIGNUM *n, *d; - RSA_get0_key(env->key, &n, &e, &d); -#else - e = env->key->e; -#endif /* defined(OPENSSL_1_1_API) */ - return BN_is_word(e, 65537); -} - -/** Compare the public-key components of a and b. Return less than 0 - * if a\<b, 0 if a==b, and greater than 0 if a\>b. A NULL key is - * considered to be less than all non-NULL keys, and equal to itself. - * - * Note that this may leak information about the keys through timing. - */ -int -crypto_pk_cmp_keys(const crypto_pk_t *a, const crypto_pk_t *b) -{ - int result; - char a_is_non_null = (a != NULL) && (a->key != NULL); - char b_is_non_null = (b != NULL) && (b->key != NULL); - char an_argument_is_null = !a_is_non_null | !b_is_non_null; - - result = tor_memcmp(&a_is_non_null, &b_is_non_null, sizeof(a_is_non_null)); - if (an_argument_is_null) - return result; - - const BIGNUM *a_n, *a_e; - const BIGNUM *b_n, *b_e; - -#ifdef OPENSSL_1_1_API - const BIGNUM *a_d, *b_d; - RSA_get0_key(a->key, &a_n, &a_e, &a_d); - RSA_get0_key(b->key, &b_n, &b_e, &b_d); -#else - a_n = a->key->n; - a_e = a->key->e; - b_n = b->key->n; - b_e = b->key->e; -#endif /* defined(OPENSSL_1_1_API) */ - - tor_assert(a_n != NULL && a_e != NULL); - tor_assert(b_n != NULL && b_e != NULL); - - result = BN_cmp(a_n, b_n); - if (result) - return result; - return BN_cmp(a_e, b_e); -} +#endif /** 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 @@ -520,98 +68,6 @@ crypto_pk_eq_keys(const crypto_pk_t *a, const crypto_pk_t *b) return (crypto_pk_cmp_keys(a, b) == 0); } -/** Return the size of the public key modulus in <b>env</b>, in bytes. */ -size_t -crypto_pk_keysize(const crypto_pk_t *env) -{ - tor_assert(env); - tor_assert(env->key); - - return (size_t) RSA_size((RSA*)env->key); -} - -/** Return the size of the public key modulus of <b>env</b>, in bits. */ -int -crypto_pk_num_bits(crypto_pk_t *env) -{ - tor_assert(env); - tor_assert(env->key); - -#ifdef OPENSSL_1_1_API - /* It's so stupid that there's no other way to check that n is valid - * before calling RSA_bits(). - */ - const BIGNUM *n, *e, *d; - RSA_get0_key(env->key, &n, &e, &d); - tor_assert(n != NULL); - - return RSA_bits(env->key); -#else /* !(defined(OPENSSL_1_1_API)) */ - tor_assert(env->key->n); - return BN_num_bits(env->key->n); -#endif /* defined(OPENSSL_1_1_API) */ -} - -/** Increase the reference count of <b>env</b>, and return it. - */ -crypto_pk_t * -crypto_pk_dup_key(crypto_pk_t *env) -{ - tor_assert(env); - tor_assert(env->key); - - env->refs++; - return env; -} - -#ifdef TOR_UNIT_TESTS -/** For testing: replace dest with src. (Dest must have a refcount - * of 1) */ -void -crypto_pk_assign_(crypto_pk_t *dest, const crypto_pk_t *src) -{ - tor_assert(dest); - tor_assert(dest->refs == 1); - tor_assert(src); - RSA_free(dest->key); - dest->key = RSAPrivateKey_dup(src->key); -} -#endif /* defined(TOR_UNIT_TESTS) */ - -/** Make a real honest-to-goodness copy of <b>env</b>, and return it. - * Returns NULL on failure. */ -crypto_pk_t * -crypto_pk_copy_full(crypto_pk_t *env) -{ - RSA *new_key; - int privatekey = 0; - tor_assert(env); - tor_assert(env->key); - - if (crypto_pk_private_ok(env)) { - new_key = RSAPrivateKey_dup(env->key); - privatekey = 1; - } else { - new_key = RSAPublicKey_dup(env->key); - } - if (!new_key) { - /* LCOV_EXCL_START - * - * We can't cause RSA*Key_dup() to fail, so we can't really test this. - */ - log_err(LD_CRYPTO, "Unable to duplicate a %s key: openssl failed.", - privatekey?"private":"public"); - crypto_log_errors(LOG_ERR, - privatekey ? "Duplicating a private key" : - "Duplicating a public key"); - tor_fragile_assert(); - return NULL; - /* LCOV_EXCL_STOP */ - } - - return crypto_new_pk_from_rsa_(new_key); -} - /** Perform a hybrid (public/secret) encryption on <b>fromlen</b> * bytes of data from <b>from</b>, with padding type 'padding', * storing the results on <b>to</b>. @@ -646,7 +102,7 @@ crypto_pk_obsolete_public_hybrid_encrypt(crypto_pk_t *env, tor_assert(to); tor_assert(fromlen < SIZE_T_CEILING); - overhead = crypto_get_rsa_padding_overhead(crypto_get_rsa_padding(padding)); + overhead = crypto_get_rsa_padding_overhead(padding); pkeylen = crypto_pk_keysize(env); if (!force && fromlen+overhead <= pkeylen) { @@ -754,179 +210,6 @@ crypto_pk_obsolete_private_hybrid_decrypt(crypto_pk_t *env, return -1; } -/** Encrypt <b>fromlen</b> bytes from <b>from</b> with the public key - * in <b>env</b>, using the padding method <b>padding</b>. On success, - * write the result to <b>to</b>, and return the number of bytes - * written. On failure, return -1. - * - * <b>tolen</b> is the number of writable bytes in <b>to</b>, and must be - * at least the length of the modulus of <b>env</b>. - */ -int -crypto_pk_public_encrypt(crypto_pk_t *env, char *to, size_t tolen, - const char *from, size_t fromlen, int padding) -{ - int r; - tor_assert(env); - tor_assert(from); - tor_assert(to); - tor_assert(fromlen<INT_MAX); - tor_assert(tolen >= crypto_pk_keysize(env)); - - r = RSA_public_encrypt((int)fromlen, - (unsigned char*)from, (unsigned char*)to, - env->key, crypto_get_rsa_padding(padding)); - if (r<0) { - crypto_log_errors(LOG_WARN, "performing RSA encryption"); - return -1; - } - return r; -} - -/** Decrypt <b>fromlen</b> bytes from <b>from</b> with the private key - * in <b>env</b>, using the padding method <b>padding</b>. On success, - * write the result to <b>to</b>, and return the number of bytes - * written. On failure, return -1. - * - * <b>tolen</b> is the number of writable bytes in <b>to</b>, and must be - * at least the length of the modulus of <b>env</b>. - */ -int -crypto_pk_private_decrypt(crypto_pk_t *env, char *to, - size_t tolen, - const char *from, size_t fromlen, - int padding, int warnOnFailure) -{ - int r; - tor_assert(env); - tor_assert(from); - tor_assert(to); - tor_assert(env->key); - tor_assert(fromlen<INT_MAX); - tor_assert(tolen >= crypto_pk_keysize(env)); - if (!crypto_pk_key_is_private(env)) - /* Not a private key */ - return -1; - - r = RSA_private_decrypt((int)fromlen, - (unsigned char*)from, (unsigned char*)to, - env->key, crypto_get_rsa_padding(padding)); - - if (r<0) { - crypto_log_errors(warnOnFailure?LOG_WARN:LOG_DEBUG, - "performing RSA decryption"); - return -1; - } - return r; -} - -/** Check the signature in <b>from</b> (<b>fromlen</b> bytes long) with the - * public key in <b>env</b>, using PKCS1 padding. On success, write the - * signed data to <b>to</b>, and return the number of bytes written. - * On failure, return -1. - * - * <b>tolen</b> is the number of writable bytes in <b>to</b>, and must be - * at least the length of the modulus of <b>env</b>. - */ -MOCK_IMPL(int, -crypto_pk_public_checksig,(const crypto_pk_t *env, char *to, - size_t tolen, - const char *from, size_t fromlen)) -{ - int r; - tor_assert(env); - tor_assert(from); - tor_assert(to); - tor_assert(fromlen < INT_MAX); - tor_assert(tolen >= crypto_pk_keysize(env)); - r = RSA_public_decrypt((int)fromlen, - (unsigned char*)from, (unsigned char*)to, - env->key, RSA_PKCS1_PADDING); - - if (r<0) { - crypto_log_errors(LOG_INFO, "checking RSA signature"); - return -1; - } - return r; -} - -/** Sign <b>fromlen</b> bytes of data from <b>from</b> with the private key in - * <b>env</b>, using PKCS1 padding. On success, write the signature to - * <b>to</b>, and return the number of bytes written. On failure, return - * -1. - * - * <b>tolen</b> is the number of writable bytes in <b>to</b>, and must be - * at least the length of the modulus of <b>env</b>. - */ -int -crypto_pk_private_sign(const crypto_pk_t *env, char *to, size_t tolen, - const char *from, size_t fromlen) -{ - int r; - tor_assert(env); - tor_assert(from); - tor_assert(to); - tor_assert(fromlen < INT_MAX); - tor_assert(tolen >= crypto_pk_keysize(env)); - if (!crypto_pk_key_is_private(env)) - /* Not a private key */ - return -1; - - r = RSA_private_encrypt((int)fromlen, - (unsigned char*)from, (unsigned char*)to, - (RSA*)env->key, RSA_PKCS1_PADDING); - if (r<0) { - crypto_log_errors(LOG_WARN, "generating RSA signature"); - return -1; - } - return r; -} - -/** ASN.1-encode the public portion of <b>pk</b> into <b>dest</b>. - * Return -1 on error, or the number of characters used on success. - */ -int -crypto_pk_asn1_encode(const crypto_pk_t *pk, char *dest, size_t dest_len) -{ - int len; - unsigned char *buf = NULL; - - len = i2d_RSAPublicKey(pk->key, &buf); - if (len < 0 || buf == NULL) - return -1; - - if ((size_t)len > dest_len || dest_len > SIZE_T_CEILING) { - OPENSSL_free(buf); - return -1; - } - /* We don't encode directly into 'dest', because that would be illegal - * type-punning. (C99 is smarter than me, C99 is smarter than me...) - */ - memcpy(dest,buf,len); - OPENSSL_free(buf); - return len; -} - -/** Decode an ASN.1-encoded public key from <b>str</b>; return the result on - * success and NULL on failure. - */ -crypto_pk_t * -crypto_pk_asn1_decode(const char *str, size_t len) -{ - RSA *rsa; - unsigned char *buf; - const unsigned char *cp; - cp = buf = tor_malloc(len); - memcpy(buf,str,len); - rsa = d2i_RSAPublicKey(NULL, &cp, len); - tor_free(buf); - if (!rsa) { - crypto_log_errors(LOG_WARN,"decoding public key"); - return NULL; - } - return crypto_new_pk_from_rsa_(rsa); -} - /** Given a private or public key <b>pk</b>, put a fingerprint of the * public key into <b>fp_out</b> (must have at least FINGERPRINT_LEN+1 bytes of * space). Return 0 on success, -1 on failure. @@ -976,6 +259,26 @@ crypto_pk_get_hashed_fingerprint(crypto_pk_t *pk, char *fp_out) return 0; } +/** Copy <b>in</b> to the <b>outlen</b>-byte buffer <b>out</b>, adding spaces + * every four characters. */ +void +crypto_add_spaces_to_fp(char *out, size_t outlen, const char *in) +{ + int n = 0; + char *end = out+outlen; + tor_assert(outlen < SIZE_T_CEILING); + + while (*in && out<end) { + *out++ = *in++; + if (++n == 4 && *in && out<end) { + n = 0; + *out++ = ' '; + } + } + tor_assert(out<end); + *out = '\0'; +} + /** Check a siglen-byte long signature at <b>sig</b> against * <b>datalen</b> bytes of data at <b>data</b>, using the public key * in <b>env</b>. Return 0 if <b>sig</b> is a correct signature for @@ -1092,6 +395,188 @@ crypto_pk_get_common_digests(crypto_pk_t *pk, common_digests_t *digests_out) return rv; } +static const char RSA_PUBLIC_TAG[] = "RSA PUBLIC KEY"; +static const char RSA_PRIVATE_TAG[] = "RSA PRIVATE KEY"; + +/* These are overestimates for how many extra bytes we might need to encode + * a key in DER */ +#define PRIVATE_ASN_MAX_OVERHEAD_FACTOR 16 +#define PUBLIC_ASN_MAX_OVERHEAD_FACTOR 3 + +/** Helper: PEM-encode <b>env</b> and write it to a newly allocated string. + * If <b>private_key</b>, write the private part of <b>env</b>; otherwise + * write only the public portion. On success, set *<b>dest</b> to the new + * string, *<b>len</b> to the string's length, and return 0. On failure, + * return -1. + */ +static int +crypto_pk_write_to_string_generic(crypto_pk_t *env, + char **dest, size_t *len, + bool private_key) +{ + const int factor = + private_key ? PRIVATE_ASN_MAX_OVERHEAD_FACTOR + : PUBLIC_ASN_MAX_OVERHEAD_FACTOR; + size_t buflen = crypto_pk_keysize(env) * factor; + const char *tag = + private_key ? RSA_PRIVATE_TAG : RSA_PUBLIC_TAG; + char *buf = tor_malloc(buflen); + char *result = NULL; + size_t resultlen = 0; + int rv = -1; + + int n = private_key + ? crypto_pk_asn1_encode_private(env, buf, buflen) + : crypto_pk_asn1_encode(env, buf, buflen); + if (n < 0) + goto done; + + resultlen = pem_encoded_size(n, tag); + result = tor_malloc(resultlen); + if (pem_encode(result, resultlen, + (const unsigned char *)buf, n, tag) < 0) { + goto done; + } + + *dest = result; + *len = resultlen; + rv = 0; + + done: + if (rv < 0 && result) { + memwipe(result, 0, resultlen); + tor_free(result); + } + memwipe(buf, 0, buflen); + tor_free(buf); + return rv; +} + +/** PEM-encode the public key portion of <b>env</b> and write it to a + * newly allocated string. On success, set *<b>dest</b> to the new + * string, *<b>len</b> to the string's length, and return 0. On + * failure, return -1. + */ +int +crypto_pk_write_public_key_to_string(crypto_pk_t *env, + char **dest, size_t *len) +{ + return crypto_pk_write_to_string_generic(env, dest, len, false); +} + +/** PEM-encode the private key portion of <b>env</b> and write it to a + * newly allocated string. On success, set *<b>dest</b> to the new + * string, *<b>len</b> to the string's length, and return 0. On + * failure, return -1. + */ +int +crypto_pk_write_private_key_to_string(crypto_pk_t *env, + char **dest, size_t *len) +{ + return crypto_pk_write_to_string_generic(env, dest, len, true); +} + +/** + * Helper. Read a PEM-encoded RSA from the first <b>len</b> characters of + * <b>src</b>, and store the result in <b>env</b>. If <b>private_key</b>, + * expect a private key; otherwise expect a public key. Return 0 on success, + * -1 on failure. If len is -1, the string is nul-terminated. + */ +static int +crypto_pk_read_from_string_generic(crypto_pk_t *env, const char *src, + size_t len, bool private_key) +{ + if (len == (size_t)-1) // "-1" indicates "use the length of the string." + len = strlen(src); + + const char *tag = + private_key ? RSA_PRIVATE_TAG : RSA_PUBLIC_TAG; + size_t buflen = len; + uint8_t *buf = tor_malloc(buflen); + int rv = -1; + + int n = pem_decode(buf, buflen, src, len, tag); + if (n < 0) + goto done; + + crypto_pk_t *pk = private_key + ? crypto_pk_asn1_decode_private((const char*)buf, n) + : crypto_pk_asn1_decode((const char*)buf, n); + if (! pk) + goto done; + + if (private_key) + crypto_pk_assign_private(env, pk); + else + crypto_pk_assign_public(env, pk); + crypto_pk_free(pk); + rv = 0; + + done: + memwipe(buf, 0, buflen); + tor_free(buf); + return rv; +} + +/** Read a PEM-encoded public key from the first <b>len</b> characters of + * <b>src</b>, and store the result in <b>env</b>. Return 0 on success, -1 on + * failure. If len is -1, the string is nul-terminated. + */ +int +crypto_pk_read_public_key_from_string(crypto_pk_t *env, + const char *src, size_t len) +{ + return crypto_pk_read_from_string_generic(env, src, len, false); +} + +/** Read a PEM-encoded private key from the <b>len</b>-byte string <b>src</b> + * into <b>env</b>. Return 0 on success, -1 on failure. If len is -1, + * the string is nul-terminated. + */ +int +crypto_pk_read_private_key_from_string(crypto_pk_t *env, + const char *src, ssize_t len) +{ + return crypto_pk_read_from_string_generic(env, src, len, true); +} + +/** Read a PEM-encoded private key from the file named by + * <b>keyfile</b> into <b>env</b>. Return 0 on success, -1 on failure. + */ +int +crypto_pk_read_private_key_from_filename(crypto_pk_t *env, + const char *keyfile) +{ + struct stat st; + char *buf = read_file_to_str(keyfile, 0, &st); + if (!buf) + return -1; + + int rv = crypto_pk_read_private_key_from_string(env, buf, st.st_size); + memwipe(buf, 0, st.st_size); + tor_free(buf); + return rv; +} + +/** Write the private key from <b>env</b> into the file named by <b>fname</b>, + * PEM-encoded. Return 0 on success, -1 on failure. + */ +int +crypto_pk_write_private_key_to_filename(crypto_pk_t *env, + const char *fname) +{ + char *s = NULL; + size_t n = 0; + + if (crypto_pk_write_private_key_to_string(env, &s, &n) < 0) + return -1; + + int rv = write_bytes_to_file(fname, s, n, 0); + memwipe(s, 0, n); + tor_free(s); + return rv; +} + /** Given a crypto_pk_t <b>pk</b>, allocate a new buffer containing the * Base64 encoding of the DER representation of the private key as a NUL * terminated string, and return it via <b>priv_out</b>. Return 0 on @@ -1100,30 +585,35 @@ crypto_pk_get_common_digests(crypto_pk_t *pk, common_digests_t *digests_out) * It is the caller's responsibility to sanitize and free the resulting buffer. */ int -crypto_pk_base64_encode(const crypto_pk_t *pk, char **priv_out) +crypto_pk_base64_encode_private(const crypto_pk_t *pk, char **priv_out) { - unsigned char *der = NULL; - int der_len; - int ret = -1; + size_t buflen = crypto_pk_keysize(pk)*16; + char *buf = tor_malloc(buflen); + char *result = NULL; + size_t reslen = 0; + bool ok = false; - *priv_out = NULL; + int n = crypto_pk_asn1_encode_private(pk, buf, buflen); - der_len = i2d_RSAPrivateKey(pk->key, &der); - if (der_len < 0 || der == NULL) - return ret; + if (n < 0) + goto done; - size_t priv_len = base64_encode_size(der_len, 0) + 1; - char *priv = tor_malloc_zero(priv_len); - if (base64_encode(priv, priv_len, (char *)der, der_len, 0) >= 0) { - *priv_out = priv; - ret = 0; - } else { - tor_free(priv); - } + reslen = base64_encode_size(n, 0)+1; + result = tor_malloc(reslen); + if (base64_encode(result, reslen, buf, n, 0) < 0) + goto done; - memwipe(der, 0, der_len); - OPENSSL_free(der); - return ret; + ok = true; + + done: + memwipe(buf, 0, buflen); + tor_free(buf); + if (result && ! ok) { + memwipe(result, 0, reslen); + tor_free(result); + } + *priv_out = result; + return ok ? 0 : -1; } /** Given a string containing the Base64 encoded DER representation of the @@ -1131,7 +621,7 @@ crypto_pk_base64_encode(const crypto_pk_t *pk, char **priv_out) * on failure. */ crypto_pk_t * -crypto_pk_base64_decode(const char *str, size_t len) +crypto_pk_base64_decode_private(const char *str, size_t len) { crypto_pk_t *pk = NULL; @@ -1142,24 +632,11 @@ crypto_pk_base64_decode(const char *str, size_t len) goto out; } - const unsigned char *dp = (unsigned char*)der; /* Shut the compiler up. */ - RSA *rsa = d2i_RSAPrivateKey(NULL, &dp, der_len); - if (!rsa) { - crypto_log_errors(LOG_WARN, "decoding private key"); - goto out; - } - - pk = crypto_new_pk_from_rsa_(rsa); - - /* Make sure it's valid. */ - if (crypto_pk_check_key(pk) <= 0) { - crypto_pk_free(pk); - pk = NULL; - goto out; - } + pk = crypto_pk_asn1_decode_private(der, der_len); out: - memwipe(der, 0, len + 1); + memwipe(der, 0, len+1); tor_free(der); + return pk; } |