annotate src/pk/pkcs1/pkcs_1_pss_encode.c @ 280:59400faa4b44 libtomcrypt-orig libtomcrypt-1.05

Re-import libtomcrypt 1.05 for cleaner propagating. From crypt-1.05.tar.bz2, SHA1 of 88250202bb51570dc64f7e8f1c943cda9479258f
author Matt Johnston <matt@ucc.asn.au>
date Wed, 08 Mar 2006 12:58:00 +0000
parents
children d5faf4814ddb
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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>
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2 *
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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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>
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4 * algorithms in a highly modular and flexible manner.
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
5 *
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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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>
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7 * guarantee it works.
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
8 *
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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9 * Tom St Denis, [email protected], http://libtomcrypt.org
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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10 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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11 #include "tomcrypt.h"
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
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12
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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13 /**
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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14 @file pkcs_1_pss_encode.c
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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15 PKCS #1 PSS Signature Padding, Tom St Denis
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
16 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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17
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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18 #ifdef PKCS_1
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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19
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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20 /**
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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21 PKCS #1 v2.00 Signature Encoding
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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22 @param msghash The hash to encode
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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23 @param msghashlen The length of the hash (octets)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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24 @param saltlen The length of the salt desired (octets)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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25 @param prng An active PRNG context
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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26 @param prng_idx The index of the PRNG desired
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
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27 @param hash_idx The index of the hash desired
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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28 @param modulus_bitlen The bit length of the RSA modulus
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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29 @param out [out] The destination of the encoding
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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30 @param outlen [in/out] The max size and resulting size of the encoded data
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
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31 @return CRYPT_OK if successful
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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32 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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33 int pkcs_1_pss_encode(const unsigned char *msghash, unsigned long msghashlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
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34 unsigned long saltlen, prng_state *prng,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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35 int prng_idx, int hash_idx,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
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36 unsigned long modulus_bitlen,
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
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37 unsigned char *out, unsigned long *outlen)
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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38 {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
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39 unsigned char *DB, *mask, *salt, *hash;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
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40 unsigned long x, y, hLen, modulus_len;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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41 int err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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42 hash_state md;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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43
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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44 LTC_ARGCHK(msghash != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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45 LTC_ARGCHK(out != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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46 LTC_ARGCHK(outlen != NULL);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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47
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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48 /* ensure hash and PRNG are valid */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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49 if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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50 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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51 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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52 if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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53 return err;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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54 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
55
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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56 hLen = hash_descriptor[hash_idx].hashsize;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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57 modulus_len = (modulus_bitlen>>3) + (modulus_bitlen & 7 ? 1 : 0);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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58
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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59 /* check sizes */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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60 if ((saltlen > modulus_len) || (modulus_len < hLen + saltlen + 2)) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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61 return CRYPT_PK_INVALID_SIZE;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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62 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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63
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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64 /* allocate ram for DB/mask/salt/hash of size modulus_len */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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65 DB = XMALLOC(modulus_len);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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66 mask = XMALLOC(modulus_len);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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67 salt = XMALLOC(modulus_len);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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68 hash = XMALLOC(modulus_len);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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69 if (DB == NULL || mask == NULL || salt == NULL || hash == NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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70 if (DB != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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71 XFREE(DB);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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72 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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73 if (mask != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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74 XFREE(mask);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
75 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
76 if (salt != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
77 XFREE(salt);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
78 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
79 if (hash != NULL) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
80 XFREE(hash);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
81 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
82 return CRYPT_MEM;
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
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
86 /* generate random salt */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
87 if (saltlen > 0) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
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diff changeset
88 if (prng_descriptor[prng_idx].read(salt, saltlen, prng) != saltlen) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
89 err = CRYPT_ERROR_READPRNG;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
90 goto LBL_ERR;
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 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
93
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
94 /* M = (eight) 0x00 || msghash || salt, hash = H(M) */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
95 if ((err = hash_descriptor[hash_idx].init(&md)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
96 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
97 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
98 zeromem(DB, 8);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
99 if ((err = hash_descriptor[hash_idx].process(&md, DB, 8)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
100 goto LBL_ERR;
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 if ((err = hash_descriptor[hash_idx].process(&md, msghash, msghashlen)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
103 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
104 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
105 if ((err = hash_descriptor[hash_idx].process(&md, salt, saltlen)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
106 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
107 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
108 if ((err = hash_descriptor[hash_idx].done(&md, hash)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
109 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
110 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
111
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
112 /* generate DB = PS || 0x01 || salt, PS == modulus_len - saltlen - hLen - 2 zero bytes */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
113 x = 0;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
114 XMEMSET(DB + x, 0, modulus_len - saltlen - hLen - 2);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
115 x += modulus_len - saltlen - hLen - 2;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
116 DB[x++] = 0x01;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
117 XMEMCPY(DB + x, salt, saltlen);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
118 x += saltlen;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
119
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
120 /* generate mask of length modulus_len - hLen - 1 from hash */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
121 if ((err = pkcs_1_mgf1(hash, hLen, hash_idx, mask, modulus_len - hLen - 1)) != CRYPT_OK) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
122 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
123 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
124
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
125 /* xor against DB */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
126 for (y = 0; y < (modulus_len - hLen - 1); y++) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
127 DB[y] ^= mask[y];
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
128 }
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 /* output is DB || hash || 0xBC */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
131 if (*outlen < modulus_len) {
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
132 err = CRYPT_BUFFER_OVERFLOW;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
133 goto LBL_ERR;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
134 }
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
135
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
136 /* DB len = modulus_len - hLen - 1 */
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
137 y = 0;
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
138 XMEMCPY(out + y, DB, modulus_len - hLen - 1);
59400faa4b44 Re-import libtomcrypt 1.05 for cleaner propagating.
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
139 y += modulus_len - hLen - 1;
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140
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141 /* hash */
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142 XMEMCPY(out + y, hash, hLen);
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143 y += hLen;
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144
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145 /* 0xBC */
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146 out[y] = 0xBC;
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147
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148 /* now clear the 8*modulus_len - modulus_bitlen most significant bits */
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149 out[0] &= 0xFF >> ((modulus_len<<3) - (modulus_bitlen-1));
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150
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151 /* store output size */
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152 *outlen = modulus_len;
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153 err = CRYPT_OK;
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154 LBL_ERR:
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155 #ifdef LTC_CLEAN_STACK
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156 zeromem(DB, modulus_len);
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157 zeromem(mask, modulus_len);
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Matt Johnston <matt@ucc.asn.au>
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158 zeromem(salt, modulus_len);
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159 zeromem(hash, modulus_len);
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160 #endif
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161
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162 XFREE(hash);
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163 XFREE(salt);
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164 XFREE(mask);
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165 XFREE(DB);
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166
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167 return err;
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168 }
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169
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170 #endif /* PKCS_1 */
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171
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172 /* $Source: /cvs/libtom/libtomcrypt/src/pk/pkcs1/pkcs_1_pss_encode.c,v $ */
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173 /* $Revision: 1.4 $ */
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174 /* $Date: 2005/05/05 14:35:59 $ */