Faster look-up for spec by algo for digests, ciphers and MAC

* cipher/cipher.c (cipher_list_algo0, cipher_list_algo301): New cipher
spec lists with same order and spacing as 'gcry_cipher_algos'
enumeration.
(spec_from_algo): Use new spec lists for faster look-up.
* cipher/mac.c (mac_list_algo101, mac_list_algo201, mac_list_algo401)
(mac_list_algo501): New MAC spec lists with same order and spacing as
'gcry_mac_algos' enumeration.
(spec_from_algo): Use new spec lists for faster look-up.
* cipher/md.c (digest_list_algo0, digest_list_algo301): New digest
spec lists with same order and spacing as 'gcry_md_algos'
enumeration.
(spec_from_algo): Use new spec lists for faster look-up.
--

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>

3 files changed, 510 insertions, 19 deletions

diff --git a/cipher/cipher.c b/cipher/cipher.c
index 1bef766c..d6cd0b42 100644
--- a/cipher/cipher.c
+++ b/cipher/cipher.c
@@ -90,6 +90,114 @@ static gcry_cipher_spec_t * const cipher_list[] =
     NULL
   };
 
+/* Cipher implementations starting with index 0 (enum gcry_cipher_algos) */
+static gcry_cipher_spec_t * const cipher_list_algo0[] =
+  {
+    NULL, /* GCRY_CIPHER_NONE */
+#ifdef USE_IDEA
+    &_gcry_cipher_spec_idea,
+#else
+    NULL,
+#endif
+#if USE_DES
+    &_gcry_cipher_spec_tripledes,
+#else
+    NULL,
+#endif
+#if USE_CAST5
+    &_gcry_cipher_spec_cast5,
+#else
+    NULL,
+#endif
+#if USE_BLOWFISH
+    &_gcry_cipher_spec_blowfish,
+#else
+    NULL,
+#endif
+    NULL, /* GCRY_CIPHER_SAFER_SK128 */
+    NULL, /* GCRY_CIPHER_DES_SK */
+#if USE_AES
+    &_gcry_cipher_spec_aes,
+    &_gcry_cipher_spec_aes192,
+    &_gcry_cipher_spec_aes256,
+#else
+    NULL,
+    NULL,
+    NULL,
+#endif
+#if USE_TWOFISH
+    &_gcry_cipher_spec_twofish
+#else
+    NULL
+#endif
+  };
+
+/* Cipher implementations starting with index 301 (enum gcry_cipher_algos) */
+static gcry_cipher_spec_t * const cipher_list_algo301[] =
+  {
+#if USE_ARCFOUR
+    &_gcry_cipher_spec_arcfour,
+#else
+    NULL,
+#endif
+#if USE_DES
+    &_gcry_cipher_spec_des,
+#else
+    NULL,
+#endif
+#if USE_TWOFISH
+    &_gcry_cipher_spec_twofish128,
+#else
+    NULL,
+#endif
+#if USE_SERPENT
+    &_gcry_cipher_spec_serpent128,
+    &_gcry_cipher_spec_serpent192,
+    &_gcry_cipher_spec_serpent256,
+#else
+    NULL,
+    NULL,
+    NULL,
+#endif
+#if USE_RFC2268
+    &_gcry_cipher_spec_rfc2268_40,
+    &_gcry_cipher_spec_rfc2268_128,
+#else
+    NULL,
+    NULL,
+#endif
+#if USE_SEED
+    &_gcry_cipher_spec_seed,
+#else
+    NULL,
+#endif
+#if USE_CAMELLIA
+    &_gcry_cipher_spec_camellia128,
+    &_gcry_cipher_spec_camellia192,
+    &_gcry_cipher_spec_camellia256,
+#else
+    NULL,
+    NULL,
+    NULL,
+#endif
+#if USE_SALSA20
+    &_gcry_cipher_spec_salsa20,
+    &_gcry_cipher_spec_salsa20r12,
+#else
+    NULL,
+    NULL,
+#endif
+#if USE_GOST28147
+    &_gcry_cipher_spec_gost28147,
+#else
+    NULL,
+#endif
+#if USE_CHACHA20
+    &_gcry_cipher_spec_chacha20
+#else
+    NULL,
+#endif
+  };
 
 
 
@@ -105,15 +213,19 @@ map_algo (int algo)
 static gcry_cipher_spec_t *
 spec_from_algo (int algo)
 {
-  int idx;
-  gcry_cipher_spec_t *spec;
+  gcry_cipher_spec_t *spec = NULL;
 
   algo = map_algo (algo);
 
-  for (idx = 0; (spec = cipher_list[idx]); idx++)
-    if (algo == spec->algo)
-      return spec;
-  return NULL;
+  if (algo >= 0 && algo < DIM(cipher_list_algo0))
+    spec = cipher_list_algo0[algo];
+  else if (algo >= 301 && algo < 301 + DIM(cipher_list_algo301))
+    spec = cipher_list_algo301[algo - 301];
+
+  if (spec)
+    gcry_assert (spec->algo == algo);
+
+  return spec;
 }
 
 
diff --git a/cipher/mac.c b/cipher/mac.c
index e8e7cebd..1b79bf31 100644
--- a/cipher/mac.c
+++ b/cipher/mac.c
@@ -130,6 +130,236 @@ static gcry_mac_spec_t * const mac_list[] = {
   NULL,
 };
 
+/* HMAC implementations start with index 101 (enum gcry_mac_algos) */
+static gcry_mac_spec_t * const mac_list_algo101[] =
+  {
+#if USE_SHA256
+    &_gcry_mac_type_spec_hmac_sha256,
+    &_gcry_mac_type_spec_hmac_sha224,
+#else
+    NULL,
+    NULL,
+#endif
+#if USE_SHA512
+    &_gcry_mac_type_spec_hmac_sha512,
+    &_gcry_mac_type_spec_hmac_sha384,
+#else
+    NULL,
+    NULL,
+#endif
+#if USE_SHA1
+    &_gcry_mac_type_spec_hmac_sha1,
+#else
+    NULL,
+#endif
+#if USE_MD5
+    &_gcry_mac_type_spec_hmac_md5,
+#else
+    NULL,
+#endif
+#if USE_MD4
+    &_gcry_mac_type_spec_hmac_md4,
+#else
+    NULL,
+#endif
+#if USE_RMD160
+    &_gcry_mac_type_spec_hmac_rmd160,
+#else
+    NULL,
+#endif
+#if USE_TIGER
+    &_gcry_mac_type_spec_hmac_tiger1,
+#else
+    NULL,
+#endif
+#if USE_WHIRLPOOL
+    &_gcry_mac_type_spec_hmac_whirlpool,
+#else
+    NULL,
+#endif
+#ifdef USE_GOST_R_3411_94
+    &_gcry_mac_type_spec_hmac_gost3411_94,
+#else
+    NULL,
+#endif
+#ifdef USE_GOST_R_3411_12
+    &_gcry_mac_type_spec_hmac_stribog256,
+    &_gcry_mac_type_spec_hmac_stribog512,
+#else
+    NULL,
+    NULL,
+#endif
+#if USE_MD2
+    &_gcry_mac_type_spec_hmac_md2,
+#else
+    NULL,
+#endif
+#if USE_SHA3
+    &_gcry_mac_type_spec_hmac_sha3_224,
+    &_gcry_mac_type_spec_hmac_sha3_256,
+    &_gcry_mac_type_spec_hmac_sha3_384,
+    &_gcry_mac_type_spec_hmac_sha3_512,
+#else
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+#endif
+#ifdef USE_GOST_R_3411_94
+    &_gcry_mac_type_spec_hmac_gost3411_cp,
+#else
+    NULL,
+#endif
+#if USE_BLAKE2
+    &_gcry_mac_type_spec_hmac_blake2b_512,
+    &_gcry_mac_type_spec_hmac_blake2b_384,
+    &_gcry_mac_type_spec_hmac_blake2b_256,
+    &_gcry_mac_type_spec_hmac_blake2b_160,
+    &_gcry_mac_type_spec_hmac_blake2s_256,
+    &_gcry_mac_type_spec_hmac_blake2s_224,
+    &_gcry_mac_type_spec_hmac_blake2s_160,
+    &_gcry_mac_type_spec_hmac_blake2s_128,
+#else
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+#endif
+#if USE_SM3
+    &_gcry_mac_type_spec_hmac_sm3
+#else
+    NULL
+#endif
+  };
+
+/* CMAC implementations start with index 201 (enum gcry_mac_algos) */
+static gcry_mac_spec_t * const mac_list_algo201[] =
+  {
+#if USE_AES
+    &_gcry_mac_type_spec_cmac_aes,
+#else
+    NULL,
+#endif
+#if USE_DES
+    &_gcry_mac_type_spec_cmac_tripledes,
+#else
+    NULL,
+#endif
+#if USE_CAMELLIA
+    &_gcry_mac_type_spec_cmac_camellia,
+#else
+    NULL,
+#endif
+#if USE_CAST5
+    &_gcry_mac_type_spec_cmac_cast5,
+#else
+    NULL,
+#endif
+#if USE_BLOWFISH
+    &_gcry_mac_type_spec_cmac_blowfish,
+#else
+    NULL,
+#endif
+#if USE_TWOFISH
+    &_gcry_mac_type_spec_cmac_twofish,
+#else
+    NULL,
+#endif
+#if USE_SERPENT
+    &_gcry_mac_type_spec_cmac_serpent,
+#else
+    NULL,
+#endif
+#if USE_SEED
+    &_gcry_mac_type_spec_cmac_seed,
+#else
+    NULL,
+#endif
+#if USE_RFC2268
+    &_gcry_mac_type_spec_cmac_rfc2268,
+#else
+    NULL,
+#endif
+#ifdef USE_IDEA
+    &_gcry_mac_type_spec_cmac_idea,
+#else
+    NULL,
+#endif
+#if USE_GOST28147
+    &_gcry_mac_type_spec_cmac_gost28147
+#else
+    NULL
+#endif
+  };
+
+/* GMAC implementations start with index 401 (enum gcry_mac_algos) */
+static gcry_mac_spec_t * const mac_list_algo401[] =
+  {
+#if USE_AES
+    &_gcry_mac_type_spec_gmac_aes,
+#else
+    NULL,
+#endif
+#if USE_CAMELLIA
+    &_gcry_mac_type_spec_gmac_camellia,
+#else
+    NULL,
+#endif
+#if USE_TWOFISH
+    &_gcry_mac_type_spec_gmac_twofish,
+#else
+    NULL,
+#endif
+#if USE_SERPENT
+    &_gcry_mac_type_spec_gmac_serpent,
+#else
+    NULL,
+#endif
+#if USE_SEED
+    &_gcry_mac_type_spec_gmac_seed
+#else
+    NULL
+#endif
+  };
+
+/* Poly1305-MAC implementations start with index 501 (enum gcry_mac_algos) */
+static gcry_mac_spec_t * const mac_list_algo501[] =
+  {
+    &_gcry_mac_type_spec_poly1305mac,
+#if USE_AES
+    &_gcry_mac_type_spec_poly1305mac_aes,
+#else
+    NULL,
+#endif
+#if USE_CAMELLIA
+    &_gcry_mac_type_spec_poly1305mac_camellia,
+#else
+    NULL,
+#endif
+#if USE_TWOFISH
+    &_gcry_mac_type_spec_poly1305mac_twofish,
+#else
+    NULL,
+#endif
+#if USE_SERPENT
+    &_gcry_mac_type_spec_poly1305mac_serpent,
+#else
+    NULL,
+#endif
+#if USE_SEED
+    &_gcry_mac_type_spec_poly1305mac_seed
+#else
+    NULL
+#endif
+  };
+
+
+
+
 /* Explicitly initialize this module.  */
 gcry_err_code_t
 _gcry_mac_init (void)
@@ -154,13 +384,21 @@ _gcry_mac_init (void)
 static gcry_mac_spec_t *
 spec_from_algo (int algo)
 {
-  gcry_mac_spec_t *spec;
-  int idx;
+  gcry_mac_spec_t *spec = NULL;
 
-  for (idx = 0; (spec = mac_list[idx]); idx++)
-    if (algo == spec->algo)
-      return spec;
-  return NULL;
+  if (algo >= 101 && algo < 101 + DIM(mac_list_algo101))
+    spec = mac_list_algo101[algo - 101];
+  else if (algo >= 201 && algo < 201 + DIM(mac_list_algo201))
+    spec = mac_list_algo201[algo - 201];
+  else if (algo >= 401 && algo < 401 + DIM(mac_list_algo401))
+    spec = mac_list_algo401[algo - 401];
+  else if (algo >= 501 && algo < 501 + DIM(mac_list_algo501))
+    spec = mac_list_algo501[algo - 501];
+
+  if (spec)
+    gcry_assert (spec->algo == algo);
+
+  return spec;
 }
 
 
diff --git a/cipher/md.c b/cipher/md.c
index f6c1954c..47c8cecd 100644
--- a/cipher/md.c
+++ b/cipher/md.c
@@ -101,6 +101,143 @@ static gcry_md_spec_t * const digest_list[] =
      NULL
   };
 
+/* Digest implementations starting with index 0 (enum gcry_md_algos) */
+static gcry_md_spec_t * const digest_list_algo0[] =
+  {
+    NULL, /* GCRY_MD_NONE */
+#if USE_MD5
+    &_gcry_digest_spec_md5,
+#else
+    NULL,
+#endif
+#if USE_SHA1
+    &_gcry_digest_spec_sha1,
+#else
+    NULL,
+#endif
+#if USE_RMD160
+    &_gcry_digest_spec_rmd160,
+#else
+    NULL,
+#endif
+    NULL, /* Unused index 4 */
+#if USE_MD2
+    &_gcry_digest_spec_md2,
+#else
+    NULL,
+#endif
+#if USE_TIGER
+    &_gcry_digest_spec_tiger,
+#else
+    NULL,
+#endif
+    NULL, /* GCRY_MD_HAVAL */
+#if USE_SHA256
+    &_gcry_digest_spec_sha256,
+#else
+    NULL,
+#endif
+#if USE_SHA512
+    &_gcry_digest_spec_sha384,
+    &_gcry_digest_spec_sha512,
+#else
+    NULL,
+    NULL,
+#endif
+#if USE_SHA256
+    &_gcry_digest_spec_sha224
+#else
+    NULL
+#endif
+  };
+
+/* Digest implementations starting with index 301 (enum gcry_md_algos) */
+static gcry_md_spec_t * const digest_list_algo301[] =
+  {
+#if USE_MD4
+    &_gcry_digest_spec_md4,
+#else
+    NULL,
+#endif
+#if USE_CRC
+    &_gcry_digest_spec_crc32,
+    &_gcry_digest_spec_crc32_rfc1510,
+    &_gcry_digest_spec_crc24_rfc2440,
+#else
+    NULL,
+    NULL,
+    NULL,
+#endif
+#if USE_WHIRLPOOL
+    &_gcry_digest_spec_whirlpool,
+#else
+    NULL,
+#endif
+#if USE_TIGER
+    &_gcry_digest_spec_tiger1,
+    &_gcry_digest_spec_tiger2,
+#else
+    NULL,
+    NULL,
+#endif
+#if USE_GOST_R_3411_94
+    &_gcry_digest_spec_gost3411_94,
+#else
+    NULL,
+#endif
+#if USE_GOST_R_3411_12
+    &_gcry_digest_spec_stribog_256,
+    &_gcry_digest_spec_stribog_512,
+#else
+    NULL,
+    NULL,
+#endif
+#if USE_GOST_R_3411_94
+    &_gcry_digest_spec_gost3411_cp,
+#else
+    NULL,
+#endif
+#if USE_SHA3
+    &_gcry_digest_spec_sha3_224,
+    &_gcry_digest_spec_sha3_256,
+    &_gcry_digest_spec_sha3_384,
+    &_gcry_digest_spec_sha3_512,
+    &_gcry_digest_spec_shake128,
+    &_gcry_digest_spec_shake256,
+#else
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+#endif
+#if USE_BLAKE2
+    &_gcry_digest_spec_blake2b_512,
+    &_gcry_digest_spec_blake2b_384,
+    &_gcry_digest_spec_blake2b_256,
+    &_gcry_digest_spec_blake2b_160,
+    &_gcry_digest_spec_blake2s_256,
+    &_gcry_digest_spec_blake2s_224,
+    &_gcry_digest_spec_blake2s_160,
+    &_gcry_digest_spec_blake2s_128,
+#else
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+#endif
+#if USE_SM3
+    &_gcry_digest_spec_sm3
+#else
+    NULL
+#endif
+  };
+
 
 typedef struct gcry_md_list
 {
@@ -118,7 +255,7 @@ struct gcry_md_context
   size_t actual_handle_size;     /* Allocated size of this handle. */
   FILE  *debug;
   struct {
-    unsigned int secure: 1;
+    unsigned int secure:1;
     unsigned int finalized:1;
     unsigned int bugemu1:1;
     unsigned int hmac:1;
@@ -153,15 +290,19 @@ map_algo (int algo)
 static gcry_md_spec_t *
 spec_from_algo (int algo)
 {
-  int idx;
-  gcry_md_spec_t *spec;
+  gcry_md_spec_t *spec = NULL;
 
   algo = map_algo (algo);
 
-  for (idx = 0; (spec = digest_list[idx]); idx++)
-    if (algo == spec->algo)
-      return spec;
-  return NULL;
+  if (algo >= 0 && algo < DIM(digest_list_algo0))
+    spec = digest_list_algo0[algo];
+  else if (algo >= 301 && algo < 301 + DIM(digest_list_algo301))
+    spec = digest_list_algo301[algo - 301];
+
+  if (spec)
+    gcry_assert (spec->algo == algo);
+
+  return spec;
 }