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comparison libtomcrypt/src/pk/ecc/ecc_sign_hash.c @ 1711:e9dba7abd939

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Merge libtomcrypt v1.18.2
author Matt Johnston <matt@ucc.asn.au>
date Wed, 10 Jun 2020 23:16:13 +0800
parents 1ff2a1034c52
children
comparison
equal deleted inserted replaced
1710:1ff2a1034c52 1711:e9dba7abd939
19 static int _ecc_sign_hash(const unsigned char *in, unsigned long inlen, 19 static int _ecc_sign_hash(const unsigned char *in, unsigned long inlen,
20 unsigned char *out, unsigned long *outlen, 20 unsigned char *out, unsigned long *outlen,
21 prng_state *prng, int wprng, ecc_key *key, int sigformat) 21 prng_state *prng, int wprng, ecc_key *key, int sigformat)
22 { 22 {
23 ecc_key pubkey; 23 ecc_key pubkey;
24 void *r, *s, *e, *p; 24 void *r, *s, *e, *p, *b;
25 int err, max_iterations = LTC_PK_MAX_RETRIES; 25 int err, max_iterations = LTC_PK_MAX_RETRIES;
26 unsigned long pbits, pbytes, i, shift_right; 26 unsigned long pbits, pbytes, i, shift_right;
27 unsigned char ch, buf[MAXBLOCKSIZE]; 27 unsigned char ch, buf[MAXBLOCKSIZE];
28 28
29 LTC_ARGCHK(in != NULL); 29 LTC_ARGCHK(in != NULL);
44 if ((err = prng_is_valid(wprng)) != CRYPT_OK) { 44 if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
45 return err; 45 return err;
46 } 46 }
47 47
48 /* init the bignums */ 48 /* init the bignums */
49 if ((err = mp_init_multi(&r, &s, &p, &e, NULL)) != CRYPT_OK) { 49 if ((err = mp_init_multi(&r, &s, &p, &e, &b, NULL)) != CRYPT_OK) {
50 return err; 50 return err;
51 } 51 }
52 if ((err = mp_read_radix(p, (char *)key->dp->order, 16)) != CRYPT_OK) { goto errnokey; } 52 if ((err = mp_read_radix(p, (char *)key->dp->order, 16)) != CRYPT_OK) { goto errnokey; }
53 53
54 /* get the hash and load it as a bignum into 'e' */ 54 /* get the hash and load it as a bignum into 'e' */
80 if ((err = mp_mod(pubkey.pubkey.x, p, r)) != CRYPT_OK) { goto error; } 80 if ((err = mp_mod(pubkey.pubkey.x, p, r)) != CRYPT_OK) { goto error; }
81 81
82 if (mp_iszero(r) == LTC_MP_YES) { 82 if (mp_iszero(r) == LTC_MP_YES) {
83 ecc_free(&pubkey); 83 ecc_free(&pubkey);
84 } else { 84 } else {
85 if ((err = rand_bn_upto(b, p, prng, wprng)) != CRYPT_OK) { goto error; } /* b = blinding value */
85 /* find s = (e + xr)/k */ 86 /* find s = (e + xr)/k */
86 if ((err = mp_invmod(pubkey.k, p, pubkey.k)) != CRYPT_OK) { goto error; } /* k = 1/k */ 87 if ((err = mp_mulmod(pubkey.k, b, p, pubkey.k)) != CRYPT_OK) { goto error; } /* k = kb */
88 if ((err = mp_invmod(pubkey.k, p, pubkey.k)) != CRYPT_OK) { goto error; } /* k = 1/kb */
87 if ((err = mp_mulmod(key->k, r, p, s)) != CRYPT_OK) { goto error; } /* s = xr */ 89 if ((err = mp_mulmod(key->k, r, p, s)) != CRYPT_OK) { goto error; } /* s = xr */
88 if ((err = mp_add(e, s, s)) != CRYPT_OK) { goto error; } /* s = e + xr */ 90 if ((err = mp_mulmod(pubkey.k, s, p, s)) != CRYPT_OK) { goto error; } /* s = xr/kb */
89 if ((err = mp_mod(s, p, s)) != CRYPT_OK) { goto error; } /* s = e + xr */ 91 if ((err = mp_mulmod(pubkey.k, e, p, e)) != CRYPT_OK) { goto error; } /* e = e/kb */
90 if ((err = mp_mulmod(s, pubkey.k, p, s)) != CRYPT_OK) { goto error; } /* s = (e + xr)/k */ 92 if ((err = mp_add(e, s, s)) != CRYPT_OK) { goto error; } /* s = e/kb + xr/kb */
93 if ((err = mp_mulmod(s, b, p, s)) != CRYPT_OK) { goto error; } /* s = b(e/kb + xr/kb) = (e + xr)/k */
91 ecc_free(&pubkey); 94 ecc_free(&pubkey);
92 if (mp_iszero(s) == LTC_MP_NO) { 95 if (mp_iszero(s) == LTC_MP_NO) {
93 break; 96 break;
94 } 97 }
95 } 98 }
119 } 122 }
120 goto errnokey; 123 goto errnokey;
121 error: 124 error:
122 ecc_free(&pubkey); 125 ecc_free(&pubkey);
123 errnokey: 126 errnokey:
124 mp_clear_multi(r, s, p, e, NULL); 127 mp_clear_multi(r, s, p, e, b, NULL);
125 return err; 128 return err;
126 } 129 }
127 130
128 /** 131 /**
129 Sign a message digest 132 Sign a message digest