diff options
Diffstat (limited to 'libtomcrypt/pk/dsa/dsa_sign_hash.c')
| -rw-r--r-- | libtomcrypt/pk/dsa/dsa_sign_hash.c | 200 |
1 files changed, 113 insertions, 87 deletions
diff --git a/libtomcrypt/pk/dsa/dsa_sign_hash.c b/libtomcrypt/pk/dsa/dsa_sign_hash.c index 6f4dad8..897241f 100644 --- a/libtomcrypt/pk/dsa/dsa_sign_hash.c +++ b/libtomcrypt/pk/dsa/dsa_sign_hash.c @@ -10,7 +10,6 @@ */ #include "tomcrypt.h" - /** @file dsa_sign_hash.c DSA implementation, sign a hash, Tom St Denis @@ -27,78 +26,106 @@ @param key A private DSA key @return CRYPT_OK if successful */ -int dsa_sign_hash_raw(const unsigned char *in, unsigned long inlen, - mp_int_t r, mp_int_t s, - dsa_key *key) +int dsa_sign_hash_raw(const unsigned char *in, unsigned long inlen, + mp_int_t r, mp_int_t s, dsa_key * key) { - mp_int k, kinv, tmp; - unsigned char *buf; - int err; - - LTC_ARGCHK(in != NULL); - LTC_ARGCHK(r != NULL); - LTC_ARGCHK(s != NULL); - LTC_ARGCHK(key != NULL); - - if (key->type != PK_PRIVATE) { - return CRYPT_PK_NOT_PRIVATE; - } - - /* check group order size */ - if (key->qord >= LTC_MDSA_MAX_GROUP) { - return CRYPT_INVALID_ARG; - } - - buf = XMALLOC(LTC_MDSA_MAX_GROUP); - if (buf == NULL) { - return CRYPT_MEM; - } - - /* Init our temps */ - if ((err = mp_init_multi(&k, &kinv, &tmp, NULL)) != CRYPT_OK) { goto ERRBUF; } + mp_int k, kinv, tmp; + unsigned char *buf; + int err; + + LTC_ARGCHK(in != NULL); + LTC_ARGCHK(r != NULL); + LTC_ARGCHK(s != NULL); + LTC_ARGCHK(key != NULL); + + if (key->type != PK_PRIVATE) { + return CRYPT_PK_NOT_PRIVATE; + } + + /* check group order size */ + if (key->qord >= LTC_MDSA_MAX_GROUP) { + return CRYPT_INVALID_ARG; + } + + buf = XMALLOC(LTC_MDSA_MAX_GROUP); + if (buf == NULL) { + return CRYPT_MEM; + } + + /* Init our temps */ + if ((err = mp_init_multi(&k, &kinv, &tmp, NULL)) != CRYPT_OK) { + goto ERRBUF; + } retry: - do { - /* gen random k */ - get_random_bytes(buf, key->qord); - - /* read k */ - if ((err = mp_read_unsigned_bin(&k, buf, key->qord)) != CRYPT_OK) { goto error; } - - /* k > 1 ? */ - if (mp_cmp_d(&k, 1) != LTC_MP_GT) { goto retry; } - - /* test gcd */ - if ((err = mp_gcd(&k, &key->q, &tmp)) != CRYPT_OK) { goto error; } - } while (mp_cmp_d(&tmp, 1) != LTC_MP_EQ); - - /* now find 1/k mod q */ - if ((err = mp_invmod(&k, &key->q, &kinv)) != CRYPT_OK) { goto error; } - - /* now find r = g^k mod p mod q */ - if ((err = mp_exptmod(&key->g, &k, &key->p, r)) != CRYPT_OK) { goto error; } - if ((err = mp_mod(r, &key->q, r)) != CRYPT_OK) { goto error; } - - if (mp_iszero(r) == LTC_MP_YES) { goto retry; } - - /* now find s = (in + xr)/k mod q */ - if ((err = mp_read_unsigned_bin(&tmp, (unsigned char *)in, inlen)) != CRYPT_OK) { goto error; } - if ((err = mp_mul(&key->x, r, s)) != CRYPT_OK) { goto error; } - if ((err = mp_add(s, &tmp, s)) != CRYPT_OK) { goto error; } - if ((err = mp_mulmod(s, &kinv, &key->q, s)) != CRYPT_OK) { goto error; } - - if (mp_iszero(s) == LTC_MP_YES) { goto retry; } - - err = CRYPT_OK; -error: - mp_clear_multi(&k, &kinv, &tmp, NULL); + do { + /* gen random k */ + get_random_bytes(buf, key->qord); + + /* read k */ + if ((err = + mp_read_unsigned_bin(&k, buf, key->qord)) != CRYPT_OK) { + goto error; + } + + /* k > 1 ? */ + if (mp_cmp_d(&k, 1) != LTC_MP_GT) { + goto retry; + } + + /* test gcd */ + if ((err = mp_gcd(&k, &key->q, &tmp)) != CRYPT_OK) { + goto error; + } + } while (mp_cmp_d(&tmp, 1) != LTC_MP_EQ); + + /* now find 1/k mod q */ + if ((err = mp_invmod(&k, &key->q, &kinv)) != CRYPT_OK) { + goto error; + } + + /* now find r = g^k mod p mod q */ + if ((err = mp_exptmod(&key->g, &k, &key->p, r)) != CRYPT_OK) { + goto error; + } + if ((err = mp_mod(r, &key->q, r)) != CRYPT_OK) { + goto error; + } + + if (mp_iszero(r) == LTC_MP_YES) { + goto retry; + } + + /* now find s = (in + xr)/k mod q */ + if ((err = + mp_read_unsigned_bin(&tmp, (unsigned char *)in, + inlen)) != CRYPT_OK) { + goto error; + } + if ((err = mp_mul(&key->x, r, s)) != CRYPT_OK) { + goto error; + } + if ((err = mp_add(s, &tmp, s)) != CRYPT_OK) { + goto error; + } + if ((err = mp_mulmod(s, &kinv, &key->q, s)) != CRYPT_OK) { + goto error; + } + + if (mp_iszero(s) == LTC_MP_YES) { + goto retry; + } + + err = CRYPT_OK; +error: + mp_clear_multi(&k, &kinv, &tmp, NULL); ERRBUF: #ifdef LTC_CLEAN_STACK - zeromem(buf, LTC_MDSA_MAX_GROUP); + zeromem(buf, LTC_MDSA_MAX_GROUP); #endif - XFREE(buf); - return err; + XFREE(buf); + return err; } /** @@ -110,34 +137,33 @@ ERRBUF: @param key A private DSA key @return CRYPT_OK if successful */ -int dsa_sign_hash(const unsigned char *in, unsigned long inlen, - unsigned char *out, unsigned long *outlen, - dsa_key *key) +int dsa_sign_hash(const unsigned char *in, unsigned long inlen, + unsigned char *out, unsigned long *outlen, dsa_key * key) { - mp_int r, s; - int err; + mp_int r, s; + int err; - LTC_ARGCHK(in != NULL); - LTC_ARGCHK(out != NULL); - LTC_ARGCHK(outlen != NULL); - LTC_ARGCHK(key != NULL); + LTC_ARGCHK(in != NULL); + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + LTC_ARGCHK(key != NULL); - if (mp_init_multi(&r, &s, NULL) != CRYPT_OK) { - return CRYPT_MEM; - } + if (mp_init_multi(&r, &s, NULL) != CRYPT_OK) { + return CRYPT_MEM; + } - if ((err = dsa_sign_hash_raw(in, inlen, &r, &s, key)) != CRYPT_OK) { - goto error; - } + if ((err = dsa_sign_hash_raw(in, inlen, &r, &s, key)) != CRYPT_OK) { + goto error; + } - err = der_encode_sequence_multi(out, outlen, - LTC_ASN1_INTEGER, 1UL, &r, - LTC_ASN1_INTEGER, 1UL, &s, - LTC_ASN1_EOL, 0UL, NULL); + err = der_encode_sequence_multi(out, outlen, + LTC_ASN1_INTEGER, 1UL, &r, + LTC_ASN1_INTEGER, 1UL, &s, + LTC_ASN1_EOL, 0UL, NULL); error: - mp_clear_multi(&r, &s, NULL); - return err; + mp_clear_multi(&r, &s, NULL); + return err; } #endif |