Refactor crypto.[ch] into smaller xof+digest module.

Add two new files (crypto_digest.c, crypto_digest.h) as new module of
crypto.[ch].  This new module includes all functions and dependencies related
to digest and xof operations. Those have been removed from crypto.[ch].

Follows #24658.

Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>

1 files changed, 0 insertions, 584 deletions

diff --git a/src/common/crypto.c b/src/common/crypto.c
index 2ecf64c393..88cf353a15 100644
--- a/src/common/crypto.c
+++ b/src/common/crypto.c
@@ -399,70 +399,6 @@ crypto_cipher_free_(crypto_cipher_t *env)
 
 /* public key crypto */
 
-/** 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
- * SHA1(data).  Else return -1.
- */
-MOCK_IMPL(int,
-crypto_pk_public_checksig_digest,(crypto_pk_t *env, const char *data,
-                                  size_t datalen, const char *sig,
-                                  size_t siglen))
-{
-  char digest[DIGEST_LEN];
-  char *buf;
-  size_t buflen;
-  int r;
-
-  tor_assert(env);
-  tor_assert(data);
-  tor_assert(sig);
-  tor_assert(datalen < SIZE_T_CEILING);
-  tor_assert(siglen < SIZE_T_CEILING);
-
-  if (crypto_digest(digest,data,datalen)<0) {
-    log_warn(LD_BUG, "couldn't compute digest");
-    return -1;
-  }
-  buflen = crypto_pk_keysize(env);
-  buf = tor_malloc(buflen);
-  r = crypto_pk_public_checksig(env,buf,buflen,sig,siglen);
-  if (r != DIGEST_LEN) {
-    log_warn(LD_CRYPTO, "Invalid signature");
-    tor_free(buf);
-    return -1;
-  }
-  if (tor_memneq(buf, digest, DIGEST_LEN)) {
-    log_warn(LD_CRYPTO, "Signature mismatched with digest.");
-    tor_free(buf);
-    return -1;
-  }
-  tor_free(buf);
-
-  return 0;
-}
-
-/** Compute a SHA1 digest of <b>fromlen</b> bytes of data stored at
- * <b>from</b>; sign the data with the private key in <b>env</b>, and
- * store it in <b>to</b>.  Return the number of bytes written on
- * success, and -1 on failure.
- *
- * <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_digest(crypto_pk_t *env, char *to, size_t tolen,
-                              const char *from, size_t fromlen)
-{
-  int r;
-  char digest[DIGEST_LEN];
-  if (crypto_digest(digest,from,fromlen)<0)
-    return -1;
-  r = crypto_pk_private_sign(env,to,tolen,digest,DIGEST_LEN);
-  memwipe(digest, 0, sizeof(digest));
-  return r;
-}
-
 /** 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>.
@@ -605,58 +541,6 @@ crypto_pk_obsolete_private_hybrid_decrypt(crypto_pk_t *env,
   return -1;
 }
 
-/** Given a private or public key <b>pk</b>, put a SHA1 hash of the
- * public key into <b>digest_out</b> (must have DIGEST_LEN bytes of space).
- * Return 0 on success, -1 on failure.
- */
-int
-crypto_pk_get_digest(const crypto_pk_t *pk, char *digest_out)
-{
-  char *buf;
-  size_t buflen;
-  int len;
-  int rv = -1;
-
-  buflen = crypto_pk_keysize(pk)*2;
-  buf = tor_malloc(buflen);
-  len = crypto_pk_asn1_encode(pk, buf, buflen);
-  if (len < 0)
-    goto done;
-
-  if (crypto_digest(digest_out, buf, len) < 0)
-    goto done;
-
-  rv = 0;
-  done:
-  tor_free(buf);
-  return rv;
-}
-
-/** Compute all digests of the DER encoding of <b>pk</b>, and store them
- * in <b>digests_out</b>.  Return 0 on success, -1 on failure. */
-int
-crypto_pk_get_common_digests(crypto_pk_t *pk, common_digests_t *digests_out)
-{
-  char *buf;
-  size_t buflen;
-  int len;
-  int rv = -1;
-
-  buflen = crypto_pk_keysize(pk)*2;
-  buf = tor_malloc(buflen);
-  len = crypto_pk_asn1_encode(pk, buf, buflen);
-  if (len < 0)
-    goto done;
-
-  if (crypto_common_digests(digests_out, (char*)buf, len) < 0)
-    goto done;
-
-  rv = 0;
- done:
-  tor_free(buf);
-  return rv;
-}
-
 /** Copy <b>in</b> to the <b>outlen</b>-byte buffer <b>out</b>, adding spaces
  * every four characters. */
 void
@@ -788,474 +672,6 @@ crypto_cipher_decrypt_with_iv(const char *key,
   return (int)(fromlen - CIPHER_IV_LEN);
 }
 
-/* SHA-1 */
-
-/** 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.
- */
-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
-    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)
-    ret = (SHA512((const unsigned char*)m,len,(unsigned char*)digest)
-           != NULL);
-  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. */
-int
-crypto_common_digests(common_digests_t *ds_out, const char *m, size_t len)
-{
-  tor_assert(ds_out);
-  memset(ds_out, 0, sizeof(*ds_out));
-  if (crypto_digest(ds_out->d[DIGEST_SHA1], m, len) < 0)
-    return -1;
-  if (crypto_digest256(ds_out->d[DIGEST_SHA256], m, len, DIGEST_SHA256) < 0)
-    return -1;
-
-  return 0;
-}
-
-/** Return the name of an algorithm, as used in directory documents. */
-const char *
-crypto_digest_algorithm_get_name(digest_algorithm_t alg)
-{
-  switch (alg) {
-    case DIGEST_SHA1:
-      return "sha1";
-    case DIGEST_SHA256:
-      return "sha256";
-    case DIGEST_SHA512:
-      return "sha512";
-    case DIGEST_SHA3_256:
-      return "sha3-256";
-    case DIGEST_SHA3_512:
-      return "sha3-512";
-      // LCOV_EXCL_START
-    default:
-      tor_fragile_assert();
-      return "??unknown_digest??";
-      // LCOV_EXCL_STOP
-  }
-}
-
-/** Given the name of a digest algorithm, return its integer value, or -1 if
- * the name is not recognized. */
-int
-crypto_digest_algorithm_parse_name(const char *name)
-{
-  if (!strcmp(name, "sha1"))
-    return DIGEST_SHA1;
-  else if (!strcmp(name, "sha256"))
-    return DIGEST_SHA256;
-  else if (!strcmp(name, "sha512"))
-    return DIGEST_SHA512;
-  else if (!strcmp(name, "sha3-256"))
-    return DIGEST_SHA3_256;
-  else if (!strcmp(name, "sha3-512"))
-    return DIGEST_SHA3_512;
-  else
-    return -1;
-}
-
-/** Given an algorithm, return the digest length in bytes. */
-size_t
-crypto_digest_algorithm_get_length(digest_algorithm_t alg)
-{
-  switch (alg) {
-    case DIGEST_SHA1:
-      return DIGEST_LEN;
-    case DIGEST_SHA256:
-      return DIGEST256_LEN;
-    case DIGEST_SHA512:
-      return DIGEST512_LEN;
-    case DIGEST_SHA3_256:
-      return DIGEST256_LEN;
-    case DIGEST_SHA3_512:
-      return DIGEST512_LEN;
-    default:
-      tor_assert(0);              // LCOV_EXCL_LINE
-      return 0; /* Unreachable */ // LCOV_EXCL_LINE
-  }
-}
-
-/** 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 */
-    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:
-      return END_OF_FIELD(d.sha1);
-    case DIGEST_SHA256:
-      return END_OF_FIELD(d.sha2);
-    case DIGEST_SHA512:
-      return END_OF_FIELD(d.sha512);
-    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:
-      SHA1_Init(&r->d.sha1);
-      break;
-    case DIGEST_SHA256:
-      SHA256_Init(&r->d.sha2);
-      break;
-    case DIGEST_SHA512:
-      SHA512_Init(&r->d.sha512);
-      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>. */
-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;
-  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.
- */
-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;
-    case DIGEST_SHA3_256: /* FALLSTHROUGH */
-    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.
- */
-void
-crypto_digest_get_digest(crypto_digest_t *digest,
-                         char *out, size_t out_len)
-{
-  unsigned char r[DIGEST512_LEN];
-  crypto_digest_t tmpenv;
-  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;
-  }
-
-  const size_t alloc_bytes = crypto_digest_alloc_bytes(digest->algorithm);
-  /* 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: /* FALLSTHROUGH */
-    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
-  }
-  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>
- */
-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);
-  return tor_memdup(digest, alloc_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);
-  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)
-{
-  unsigned char *rv = NULL;
-  /* 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);
-  rv = HMAC(EVP_sha256(), key, (int)key_len, (unsigned char*)msg, (int)msg_len,
-            (unsigned char*)hmac_out, NULL);
-  tor_assert(rv);
-}
-
-/** 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
- * <b>mac_out</b>. This function can't fail. */
-void
-crypto_mac_sha3_256(uint8_t *mac_out, size_t len_out,
-                    const uint8_t *key, size_t key_len,
-                    const uint8_t *msg, size_t msg_len)
-{
-  crypto_digest_t *digest;
-
-  const uint64_t key_len_netorder = tor_htonll(key_len);
-
-  tor_assert(mac_out);
-  tor_assert(key);
-  tor_assert(msg);
-
-  digest = crypto_digest256_new(DIGEST_SHA3_256);
-
-  /* Order matters here that is any subsystem using this function should
-   * expect this very precise ordering in the MAC construction. */
-  crypto_digest_add_bytes(digest, (const char *) &key_len_netorder,
-                          sizeof(key_len_netorder));
-  crypto_digest_add_bytes(digest, (const char *) key, key_len);
-  crypto_digest_add_bytes(digest, (const char *) msg, msg_len);
-  crypto_digest_get_digest(digest, (char *) mac_out, len_out);
-  crypto_digest_free(digest);
-}
-
 /** Internal state for a eXtendable-Output Function (XOF). */
 struct crypto_xof_t {
   keccak_state s;