dropbear: dsa_sign_hash.c annotate

author	Matt Johnston <matt@ucc.asn.au>
date	Mon, 31 May 2004 18:21:40 +0000
parents
children	5d99163f7e32

rev	line source
0 d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	2 *
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	3 * LibTomCrypt is a library that provides various cryptographic
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	4 * algorithms in a highly modular and flexible manner.
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	5 *
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	6 * The library is free for all purposes without any express
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	7 * guarantee it works.
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	8 *
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	9 * Tom St Denis, [email protected], http://libtomcrypt.org
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	10 */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	11 #include "mycrypt.h"
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	12
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	13 #ifdef MDSA
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	14
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	15 int dsa_sign_hash(const unsigned char *in, unsigned long inlen,
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	16 unsigned char out, unsigned long outlen,
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	17 prng_state prng, int wprng, dsa_key key)
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	18 {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	19 mp_int k, kinv, tmp, r, s;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	20 unsigned char buf[512];
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	21 int err, y;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	22 unsigned long len;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	23
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	24
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	25 _ARGCHK(in != NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	26 _ARGCHK(out != NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	27 _ARGCHK(outlen != NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	28 _ARGCHK(key != NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	29
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	30 if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	31 return err;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	32 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	33 if (key->type != PK_PRIVATE) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	34 return CRYPT_PK_NOT_PRIVATE;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	35 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	36
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	37 /* check group order size */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	38 if (key->qord >= (int)sizeof(buf)) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	39 return CRYPT_INVALID_ARG;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	40 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	41
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	42 /* Init our temps */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	43 if ((err = mp_init_multi(&k, &kinv, &r, &s, &tmp, NULL)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	44
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	45 retry:
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	46
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	47 do {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	48 /* gen random k */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	49 if (prng_descriptor[wprng].read(buf, key->qord, prng) != (unsigned long)key->qord) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	50 err = CRYPT_ERROR_READPRNG;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	51 goto done;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	52 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	53
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	54 /* read k */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	55 if ((err = mp_read_unsigned_bin(&k, buf, key->qord)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	56
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	57 /* k > 1 ? */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	58 if (mp_cmp_d(&k, 1) != MP_GT) { goto retry; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	59
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	60 /* test gcd */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	61 if ((err = mp_gcd(&k, &key->q, &tmp)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	62 } while (mp_cmp_d(&tmp, 1) != MP_EQ);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	63
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	64 /* now find 1/k mod q */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	65 if ((err = mp_invmod(&k, &key->q, &kinv)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	66
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	67 /* now find r = g^k mod p mod q */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	68 if ((err = mp_exptmod(&key->g, &k, &key->p, &r)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	69 if ((err = mp_mod(&r, &key->q, &r)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	70
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	71 if (mp_iszero(&r) == MP_YES) { goto retry; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	72
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	73 /* now find s = (in + xr)/k mod q */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	74 if ((err = mp_read_unsigned_bin(&tmp, (unsigned char *)in, inlen)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	75 if ((err = mp_mul(&key->x, &r, &s)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	76 if ((err = mp_add(&s, &tmp, &s)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	77 if ((err = mp_mulmod(&s, &kinv, &key->q, &s)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	78
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	79 if (mp_iszero(&s) == MP_YES) { goto retry; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	80
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	81 /* now store em both */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	82
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	83 /* first check that we have enough room */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	84 if (*outlen < (unsigned long)(PACKET_SIZE + 4 + mp_unsigned_bin_size(&s) + mp_unsigned_bin_size(&r))) {
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	85 err = CRYPT_BUFFER_OVERFLOW;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	86 goto done;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	87 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	88
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	89 /* packet header */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	90 packet_store_header(out, PACKET_SECT_DSA, PACKET_SUB_SIGNED);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	91 y = PACKET_SIZE;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	92
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	93 /* store length of r */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	94 len = mp_unsigned_bin_size(&r);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	95 out[y++] = (len>>8)&255;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	96 out[y++] = len&255;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	97
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	98 /* store r */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	99 if ((err = mp_to_unsigned_bin(&r, out+y)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	100 y += len;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	101
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	102 /* store length of s */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	103 len = mp_unsigned_bin_size(&s);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	104 out[y++] = (len>>8)&255;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	105 out[y++] = len&255;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	106
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	107 /* store s */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	108 if ((err = mp_to_unsigned_bin(&s, out+y)) != MP_OKAY) { goto error; }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	109 y += len;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	110
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	111 /* reset size */
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	112 *outlen = y;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	113
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	114 err = CRYPT_OK;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	115 goto done;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	116
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	117 error : err = mpi_to_ltc_error(err);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	118 done : mp_clear_multi(&k, &kinv, &r, &s, &tmp, NULL);
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	119 #ifdef CLEAN_STACK
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	120 zeromem(buf, sizeof(buf));
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	121 #endif
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	122 return err;
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	123 }
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	124
d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over Matt Johnston <matt@ucc.asn.au> parents: diff changeset	125 #endif

0

d7da3b1e1540 put back the 0.95 makefile which was inadvertently merged over