dropbear: src/pk/dh/dh_sys.c annotate

author	Matt Johnston <matt@ucc.asn.au>
date	Wed, 08 Mar 2006 12:58:00 +0000
parents
children

rev	line source
280 59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	2 *
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	3 * LibTomCrypt is a library that provides various cryptographic
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	4 * algorithms in a highly modular and flexible manner.
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	5 *
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	6 * The library is free for all purposes without any express
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	7 * guarantee it works.
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	8 *
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	9 * Tom St Denis, [email protected], http://libtomcrypt.org
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	10 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	11
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	12 /**
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	13 @file dh_sys.c
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	14 DH Crypto, Tom St Denis
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	15 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	16
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	17 /**
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	18 Encrypt a short symmetric key with a public DH key
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	19 @param in The symmetric key to encrypt
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	20 @param inlen The length of the key (octets)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	21 @param out [out] The ciphertext
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	22 @param outlen [in/out] The max size and resulting size of the ciphertext
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	23 @param prng An active PRNG state
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	24 @param wprng The index of the PRNG desired
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	25 @param hash The index of the hash desired (must produce a digest of size >= the size of the plaintext)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	26 @param key The public key you wish to encrypt with.
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	27 @return CRYPT_OK if successful
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	28 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	29 int dh_encrypt_key(const unsigned char *in, unsigned long inlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	30 unsigned char out, unsigned long outlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	31 prng_state *prng, int wprng, int hash,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	32 dh_key *key)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	33 {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	34 unsigned char pub_expt, dh_shared, *skey;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	35 dh_key pubkey;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	36 unsigned long x, y, z, hashsize, pubkeysize;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	37 int err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	38
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	39 LTC_ARGCHK(in != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	40 LTC_ARGCHK(out != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	41 LTC_ARGCHK(outlen != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	42 LTC_ARGCHK(key != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	43
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	44 /* check that wprng/hash are not invalid */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	45 if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	46 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	47 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	48
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	49 if ((err = hash_is_valid(hash)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	50 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	51 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	52
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	53 if (inlen > hash_descriptor[hash].hashsize) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	54 return CRYPT_INVALID_HASH;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	55 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	56
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	57 /* allocate memory */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	58 pub_expt = XMALLOC(DH_BUF_SIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	59 dh_shared = XMALLOC(DH_BUF_SIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	60 skey = XMALLOC(MAXBLOCKSIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	61 if (pub_expt == NULL \|\| dh_shared == NULL \|\| skey == NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	62 if (pub_expt != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	63 XFREE(pub_expt);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	64 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	65 if (dh_shared != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	66 XFREE(dh_shared);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	67 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	68 if (skey != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	69 XFREE(skey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	70 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	71 return CRYPT_MEM;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	72 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	73
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	74 /* make a random key and export the public copy */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	75 if ((err = dh_make_key(prng, wprng, dh_get_size(key), &pubkey)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	76 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	77 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	78
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	79 pubkeysize = DH_BUF_SIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	80 if ((err = dh_export(pub_expt, &pubkeysize, PK_PUBLIC, &pubkey)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	81 dh_free(&pubkey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	82 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	83 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	84
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	85 /* now check if the out buffer is big enough */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	86 if (*outlen < (1 + 4 + 4 + PACKET_SIZE + pubkeysize + inlen)) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	87 dh_free(&pubkey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	88 err = CRYPT_BUFFER_OVERFLOW;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	89 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	90 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	91
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	92 /* make random key */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	93 hashsize = hash_descriptor[hash].hashsize;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	94
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	95 x = DH_BUF_SIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	96 if ((err = dh_shared_secret(&pubkey, key, dh_shared, &x)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	97 dh_free(&pubkey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	98 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	99 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	100 dh_free(&pubkey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	101
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	102 z = MAXBLOCKSIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	103 if ((err = hash_memory(hash, dh_shared, x, skey, &z)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	104 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	105 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	106
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	107 /* store header */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	108 packet_store_header(out, PACKET_SECT_DH, PACKET_SUB_ENC_KEY);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	109
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	110 /* output header */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	111 y = PACKET_SIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	112
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	113 /* size of hash name and the name itself */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	114 out[y++] = hash_descriptor[hash].ID;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	115
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	116 /* length of DH pubkey and the key itself */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	117 STORE32L(pubkeysize, out+y);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	118 y += 4;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	119 for (x = 0; x < pubkeysize; x++, y++) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	120 out[y] = pub_expt[x];
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	121 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	122
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	123 /* Store the encrypted key */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	124 STORE32L(inlen, out+y);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	125 y += 4;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	126
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	127 for (x = 0; x < inlen; x++, y++) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	128 out[y] = skey[x] ^ in[x];
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	129 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	130 *outlen = y;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	131
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	132 err = CRYPT_OK;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	133 LBL_ERR:
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	134 #ifdef LTC_CLEAN_STACK
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	135 /* clean up */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	136 zeromem(pub_expt, DH_BUF_SIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	137 zeromem(dh_shared, DH_BUF_SIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	138 zeromem(skey, MAXBLOCKSIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	139 #endif
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	140 XFREE(skey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	141 XFREE(dh_shared);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	142 XFREE(pub_expt);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	143
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	144 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	145 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	146
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	147 /**
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	148 Decrypt a DH encrypted symmetric key
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	149 @param in The DH encrypted packet
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	150 @param inlen The length of the DH encrypted packet
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	151 @param out The plaintext
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	152 @param outlen [in/out] The max size and resulting size of the plaintext
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	153 @param key The private DH key corresponding to the public key that encrypted the plaintext
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	154 @return CRYPT_OK if successful
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	155 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	156 int dh_decrypt_key(const unsigned char *in, unsigned long inlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	157 unsigned char out, unsigned long outlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	158 dh_key *key)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	159 {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	160 unsigned char shared_secret, skey;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	161 unsigned long x, y, z, hashsize, keysize;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	162 int hash, err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	163 dh_key pubkey;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	164
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	165 LTC_ARGCHK(in != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	166 LTC_ARGCHK(out != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	167 LTC_ARGCHK(outlen != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	168 LTC_ARGCHK(key != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	169
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	170 /* right key type? */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	171 if (key->type != PK_PRIVATE) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	172 return CRYPT_PK_NOT_PRIVATE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	173 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	174
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	175 /* allocate ram */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	176 shared_secret = XMALLOC(DH_BUF_SIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	177 skey = XMALLOC(MAXBLOCKSIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	178 if (shared_secret == NULL \|\| skey == NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	179 if (shared_secret != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	180 XFREE(shared_secret);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	181 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	182 if (skey != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	183 XFREE(skey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	184 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	185 return CRYPT_MEM;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	186 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	187
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	188 /* check if initial header should fit */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	189 if (inlen < PACKET_SIZE+1+4+4) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	190 err = CRYPT_INVALID_PACKET;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	191 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	192 } else {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	193 inlen -= PACKET_SIZE+1+4+4;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	194 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	195
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	196 /* is header correct? */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	197 if ((err = packet_valid_header((unsigned char *)in, PACKET_SECT_DH, PACKET_SUB_ENC_KEY)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	198 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	199 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	200
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	201 /* now lets get the hash name */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	202 y = PACKET_SIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	203 hash = find_hash_id(in[y++]);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	204 if (hash == -1) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	205 err = CRYPT_INVALID_HASH;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	206 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	207 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	208
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	209 /* common values */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	210 hashsize = hash_descriptor[hash].hashsize;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	211
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	212 /* get public key */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	213 LOAD32L(x, in+y);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	214
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	215 /* now check if the imported key will fit */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	216 if (inlen < x) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	217 err = CRYPT_INVALID_PACKET;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	218 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	219 } else {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	220 inlen -= x;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	221 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	222
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	223 y += 4;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	224 if ((err = dh_import(in+y, x, &pubkey)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	225 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	226 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	227 y += x;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	228
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	229 /* make shared key */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	230 x = DH_BUF_SIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	231 if ((err = dh_shared_secret(key, &pubkey, shared_secret, &x)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	232 dh_free(&pubkey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	233 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	234 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	235 dh_free(&pubkey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	236
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	237 z = MAXBLOCKSIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	238 if ((err = hash_memory(hash, shared_secret, x, skey, &z)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	239 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	240 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	241
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	242 /* load in the encrypted key */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	243 LOAD32L(keysize, in+y);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	244
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	245 /* will the out fit as part of the input */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	246 if (inlen < keysize) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	247 err = CRYPT_INVALID_PACKET;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	248 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	249 } else {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	250 inlen -= keysize;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	251 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	252
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	253 if (keysize > *outlen) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	254 err = CRYPT_BUFFER_OVERFLOW;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	255 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	256 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	257 y += 4;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	258
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	259 *outlen = keysize;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	260
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	261 for (x = 0; x < keysize; x++, y++) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	262 out[x] = skey[x] ^ in[y];
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	263 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	264
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	265 err = CRYPT_OK;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	266 LBL_ERR:
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	267 #ifdef LTC_CLEAN_STACK
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	268 zeromem(shared_secret, DH_BUF_SIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	269 zeromem(skey, MAXBLOCKSIZE);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	270 #endif
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	271
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	272 XFREE(skey);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	273 XFREE(shared_secret);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	274
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	275 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	276 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	277
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	278 /* perform an ElGamal Signature of a hash
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	279 *
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	280 * The math works as follows. x is the private key, M is the message to sign
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	281
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	282 1. pick a random k
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	283 2. compute a = g^k mod p
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	284 3. compute b = (M - xa)/k mod p
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	285 4. Send (a,b)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	286
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	287 Now to verify with y=g^x mod p, a and b
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	288
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	289 1. compute y^a * a^b = g^(xa) * g^(k*(M-xa)/k)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	290 = g^(xa + (M - xa))
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	291 = g^M [all mod p]
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	292
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	293 2. Compare against g^M mod p [based on input hash].
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	294 3. If result of #2 == result of #1 then signature valid
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	295 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	296
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	297 /**
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	298 Sign a message digest using a DH private key
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	299 @param in The data to sign
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	300 @param inlen The length of the input (octets)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	301 @param out [out] The destination of the signature
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	302 @param outlen [in/out] The max size and resulting size of the output
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	303 @param prng An active PRNG state
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	304 @param wprng The index of the PRNG desired
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	305 @param key A private DH key
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	306 @return CRYPT_OK if successful
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	307 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	308 int dh_sign_hash(const unsigned char *in, unsigned long inlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	309 unsigned char out, unsigned long outlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	310 prng_state prng, int wprng, dh_key key)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	311 {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	312 mp_int a, b, k, m, g, p, p1, tmp;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	313 unsigned char *buf;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	314 unsigned long x, y;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	315 int err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	316
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	317 LTC_ARGCHK(in != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	318 LTC_ARGCHK(out != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	319 LTC_ARGCHK(outlen != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	320 LTC_ARGCHK(key != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	321
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	322 /* check parameters */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	323 if (key->type != PK_PRIVATE) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	324 return CRYPT_PK_NOT_PRIVATE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	325 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	326
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	327 if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	328 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	329 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	330
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	331 /* is the IDX valid ? */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	332 if (is_valid_idx(key->idx) != 1) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	333 return CRYPT_PK_INVALID_TYPE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	334 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	335
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	336 /* allocate ram for buf */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	337 buf = XMALLOC(520);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	338
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	339 /* make up a random value k,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	340 * since the order of the group is prime
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	341 * we need not check if gcd(k, r) is 1
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	342 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	343 if (prng_descriptor[wprng].read(buf, sets[key->idx].size, prng) !=
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	344 (unsigned long)(sets[key->idx].size)) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	345 err = CRYPT_ERROR_READPRNG;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	346 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	347 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	348
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	349 /* init bignums */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	350 if ((err = mp_init_multi(&a, &b, &k, &m, &p, &g, &p1, &tmp, NULL)) != MP_OKAY) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	351 err = mpi_to_ltc_error(err);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	352 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	353 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	354
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	355 /* load k and m */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	356 if ((err = mp_read_unsigned_bin(&m, (unsigned char *)in, inlen)) != MP_OKAY) { goto error; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	357 if ((err = mp_read_unsigned_bin(&k, buf, sets[key->idx].size)) != MP_OKAY) { goto error; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	358
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	359 /* load g, p and p1 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	360 if ((err = mp_read_radix(&g, sets[key->idx].base, 64)) != MP_OKAY) { goto error; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	361 if ((err = mp_read_radix(&p, sets[key->idx].prime, 64)) != MP_OKAY) { goto error; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	362 if ((err = mp_sub_d(&p, 1, &p1)) != MP_OKAY) { goto error; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	363 if ((err = mp_div_2(&p1, &p1)) != MP_OKAY) { goto error; } /* p1 = (p-1)/2 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	364
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	365 /* now get a = g^k mod p */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	366 if ((err = mp_exptmod(&g, &k, &p, &a)) != MP_OKAY) { goto error; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	367
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	368 /* now find M = xa + kb mod p1 or just b = (M - xa)/k mod p1 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	369 if ((err = mp_invmod(&k, &p1, &k)) != MP_OKAY) { goto error; } /* k = 1/k mod p1 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	370 if ((err = mp_mulmod(&a, &key->x, &p1, &tmp)) != MP_OKAY) { goto error; } /* tmp = xa */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	371 if ((err = mp_submod(&m, &tmp, &p1, &tmp)) != MP_OKAY) { goto error; } /* tmp = M - xa */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	372 if ((err = mp_mulmod(&k, &tmp, &p1, &b)) != MP_OKAY) { goto error; } /* b = (M - xa)/k */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	373
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	374 /* check for overflow */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	375 if ((unsigned long)(PACKET_SIZE + 4 + 4 + mp_unsigned_bin_size(&a) + mp_unsigned_bin_size(&b)) > *outlen) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	376 err = CRYPT_BUFFER_OVERFLOW;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	377 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	378 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	379
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	380 /* store header */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	381 y = PACKET_SIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	382
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	383 /* now store them both (a,b) */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	384 x = (unsigned long)mp_unsigned_bin_size(&a);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	385 STORE32L(x, out+y); y += 4;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	386 if ((err = mp_to_unsigned_bin(&a, out+y)) != MP_OKAY) { goto error; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	387 y += x;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	388
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	389 x = (unsigned long)mp_unsigned_bin_size(&b);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	390 STORE32L(x, out+y); y += 4;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	391 if ((err = mp_to_unsigned_bin(&b, out+y)) != MP_OKAY) { goto error; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	392 y += x;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	393
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	394 /* check if size too big */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	395 if (*outlen < y) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	396 err = CRYPT_BUFFER_OVERFLOW;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	397 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	398 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	399
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	400 /* store header */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	401 packet_store_header(out, PACKET_SECT_DH, PACKET_SUB_SIGNED);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	402 *outlen = y;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	403
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	404 err = CRYPT_OK;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	405 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	406 error:
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	407 err = mpi_to_ltc_error(err);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	408 LBL_ERR:
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	409 mp_clear_multi(&tmp, &p1, &g, &p, &m, &k, &b, &a, NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	410
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	411 XFREE(buf);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	412
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	413 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	414 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	415
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	416
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	417 /**
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	418 Verify the signature given
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	419 @param sig The signature
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	420 @param siglen The length of the signature (octets)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	421 @param hash The hash that was signed
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	422 @param hashlen The length of the hash (octets)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	423 @param stat [out] Result of signature comparison, 1==valid, 0==invalid
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	424 @param key The public DH key that signed the hash
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	425 @return CRYPT_OK if succsessful (even if signature is invalid)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	426 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	427 int dh_verify_hash(const unsigned char *sig, unsigned long siglen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	428 const unsigned char *hash, unsigned long hashlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	429 int stat, dh_key key)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	430 {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	431 mp_int a, b, p, g, m, tmp;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	432 unsigned long x, y;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	433 int err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	434
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	435 LTC_ARGCHK(sig != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	436 LTC_ARGCHK(hash != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	437 LTC_ARGCHK(stat != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	438 LTC_ARGCHK(key != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	439
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	440 /* default to invalid */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	441 *stat = 0;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	442
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	443 /* check initial input length */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	444 if (siglen < PACKET_SIZE+4+4) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	445 return CRYPT_INVALID_PACKET;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	446 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	447
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	448 /* header ok? */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	449 if ((err = packet_valid_header((unsigned char *)sig, PACKET_SECT_DH, PACKET_SUB_SIGNED)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	450 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	451 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	452
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	453 /* get hash out of packet */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	454 y = PACKET_SIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	455
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	456 /* init all bignums */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	457 if ((err = mp_init_multi(&a, &p, &b, &g, &m, &tmp, NULL)) != MP_OKAY) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	458 return mpi_to_ltc_error(err);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	459 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	460
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	461 /* load a and b */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	462 INPUT_BIGNUM(&a, sig, x, y, siglen);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	463 INPUT_BIGNUM(&b, sig, x, y, siglen);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	464
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	465 /* load p and g */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	466 if ((err = mp_read_radix(&p, sets[key->idx].prime, 64)) != MP_OKAY) { goto error1; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	467 if ((err = mp_read_radix(&g, sets[key->idx].base, 64)) != MP_OKAY) { goto error1; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	468
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	469 /* load m */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	470 if ((err = mp_read_unsigned_bin(&m, (unsigned char *)hash, hashlen)) != MP_OKAY) { goto error1; }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	471
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	472 /* find g^m mod p */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	473 if ((err = mp_exptmod(&g, &m, &p, &m)) != MP_OKAY) { goto error1; } /* m = g^m mod p */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	474
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	475 /* find y^a * a^b */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	476 if ((err = mp_exptmod(&key->y, &a, &p, &tmp)) != MP_OKAY) { goto error1; } /* tmp = y^a mod p */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	477 if ((err = mp_exptmod(&a, &b, &p, &a)) != MP_OKAY) { goto error1; } /* a = a^b mod p */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	478 if ((err = mp_mulmod(&a, &tmp, &p, &a)) != MP_OKAY) { goto error1; } /* a = y^a * a^b mod p */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	479
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	480 /* y^a * a^b == g^m ??? */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	481 if (mp_cmp(&a, &m) == 0) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	482 *stat = 1;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	483 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	484
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	485 /* clean up */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	486 err = CRYPT_OK;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	487 goto done;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	488 error1:
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	489 err = mpi_to_ltc_error(err);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	490 error:
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	491 done:
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	492 mp_clear_multi(&tmp, &m, &g, &p, &b, &a, NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	493 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	494 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	495
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	496
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	497 /* $Source: /cvs/libtom/libtomcrypt/src/pk/dh/dh_sys.c,v $ */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	498 /* $Revision: 1.3 $ */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating. Matt Johnston <matt@ucc.asn.au> parents: diff changeset	499 /* $Date: 2005/05/05 14:35:59 $ */

280

59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.