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comparison libtomcrypt/src/pk/dsa/dsa_decrypt_key.c @ 1511:5916af64acd4 fuzz

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merge from main
author Matt Johnston <matt@ucc.asn.au>
date Sat, 17 Feb 2018 19:29:51 +0800
parents 6dba84798cd5
children
comparison
equal deleted inserted replaced
1457:32f990cc96b1 1511:5916af64acd4
3 * LibTomCrypt is a library that provides various cryptographic 3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner. 4 * algorithms in a highly modular and flexible manner.
5 * 5 *
6 * The library is free for all purposes without any express 6 * The library is free for all purposes without any express
7 * guarantee it works. 7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtom.org
10 */ 8 */
11 #include "tomcrypt.h" 9 #include "tomcrypt.h"
12 10
13 /** 11 /**
14 @file dsa_decrypt_key.c 12 @file dsa_decrypt_key.c
15 DSA Crypto, Tom St Denis 13 DSA Crypto, Tom St Denis
16 */ 14 */
17 15
18 #ifdef LTC_MDSA 16 #ifdef LTC_MDSA
19 17
20 /** 18 /**
21 Decrypt an DSA encrypted key 19 Decrypt an DSA encrypted key
25 @param outlen [in/out] The max size and resulting size of the plaintext 23 @param outlen [in/out] The max size and resulting size of the plaintext
26 @param key The corresponding private DSA key 24 @param key The corresponding private DSA key
27 @return CRYPT_OK if successful 25 @return CRYPT_OK if successful
28 */ 26 */
29 int dsa_decrypt_key(const unsigned char *in, unsigned long inlen, 27 int dsa_decrypt_key(const unsigned char *in, unsigned long inlen,
30 unsigned char *out, unsigned long *outlen, 28 unsigned char *out, unsigned long *outlen,
31 dsa_key *key) 29 dsa_key *key)
32 { 30 {
33 unsigned char *skey, *expt; 31 unsigned char *skey, *expt;
34 void *g_pub; 32 void *g_pub;
35 unsigned long x, y, hashOID[32]; 33 unsigned long x, y;
34 unsigned long hashOID[32] = { 0 };
36 int hash, err; 35 int hash, err;
37 ltc_asn1_list decode[3]; 36 ltc_asn1_list decode[3];
38 37
39 LTC_ARGCHK(in != NULL); 38 LTC_ARGCHK(in != NULL);
40 LTC_ARGCHK(out != NULL); 39 LTC_ARGCHK(out != NULL);
43 42
44 /* right key type? */ 43 /* right key type? */
45 if (key->type != PK_PRIVATE) { 44 if (key->type != PK_PRIVATE) {
46 return CRYPT_PK_NOT_PRIVATE; 45 return CRYPT_PK_NOT_PRIVATE;
47 } 46 }
48 47
49 /* decode to find out hash */ 48 /* decode to find out hash */
50 LTC_SET_ASN1(decode, 0, LTC_ASN1_OBJECT_IDENTIFIER, hashOID, sizeof(hashOID)/sizeof(hashOID[0])); 49 LTC_SET_ASN1(decode, 0, LTC_ASN1_OBJECT_IDENTIFIER, hashOID, sizeof(hashOID)/sizeof(hashOID[0]));
51 50 err = der_decode_sequence(in, inlen, decode, 1);
52 if ((err = der_decode_sequence(in, inlen, decode, 1)) != CRYPT_OK) { 51 if (err != CRYPT_OK && err != CRYPT_INPUT_TOO_LONG) {
53 return err; 52 return err;
54 } 53 }
55 54
56 hash = find_hash_oid(hashOID, decode[0].size); 55 hash = find_hash_oid(hashOID, decode[0].size);
57 if (hash_is_valid(hash) != CRYPT_OK) { 56 if (hash_is_valid(hash) != CRYPT_OK) {
58 return CRYPT_INVALID_PACKET; 57 return CRYPT_INVALID_PACKET;
59 } 58 }
60 59
61 /* we now have the hash! */ 60 /* we now have the hash! */
62 61
63 if ((err = mp_init(&g_pub)) != CRYPT_OK) { 62 if ((err = mp_init(&g_pub)) != CRYPT_OK) {
64 return err; 63 return err;
65 } 64 }
66 65
67 /* allocate memory */ 66 /* allocate memory */
75 XFREE(skey); 74 XFREE(skey);
76 } 75 }
77 mp_clear(g_pub); 76 mp_clear(g_pub);
78 return CRYPT_MEM; 77 return CRYPT_MEM;
79 } 78 }
80 79
81 LTC_SET_ASN1(decode, 1, LTC_ASN1_INTEGER, g_pub, 1UL); 80 LTC_SET_ASN1(decode, 1, LTC_ASN1_INTEGER, g_pub, 1UL);
82 LTC_SET_ASN1(decode, 2, LTC_ASN1_OCTET_STRING, skey, MAXBLOCKSIZE); 81 LTC_SET_ASN1(decode, 2, LTC_ASN1_OCTET_STRING, skey, MAXBLOCKSIZE);
83 82
84 /* read the structure in now */ 83 /* read the structure in now */
85 if ((err = der_decode_sequence(in, inlen, decode, 3)) != CRYPT_OK) { 84 if ((err = der_decode_sequence(in, inlen, decode, 3)) != CRYPT_OK) {
90 x = mp_unsigned_bin_size(key->p) + 1; 89 x = mp_unsigned_bin_size(key->p) + 1;
91 if ((err = dsa_shared_secret(key->x, g_pub, key, expt, &x)) != CRYPT_OK) { 90 if ((err = dsa_shared_secret(key->x, g_pub, key, expt, &x)) != CRYPT_OK) {
92 goto LBL_ERR; 91 goto LBL_ERR;
93 } 92 }
94 93
95 y = MIN(mp_unsigned_bin_size(key->p) + 1, MAXBLOCKSIZE); 94 y = mp_unsigned_bin_size(key->p) + 1;
95 y = MIN(y, MAXBLOCKSIZE);
96 if ((err = hash_memory(hash, expt, x, expt, &y)) != CRYPT_OK) { 96 if ((err = hash_memory(hash, expt, x, expt, &y)) != CRYPT_OK) {
97 goto LBL_ERR; 97 goto LBL_ERR;
98 } 98 }
99 99
100 /* ensure the hash of the shared secret is at least as big as the encrypt itself */ 100 /* ensure the hash of the shared secret is at least as big as the encrypt itself */
123 zeromem(skey, MAXBLOCKSIZE); 123 zeromem(skey, MAXBLOCKSIZE);
124 #endif 124 #endif
125 125
126 XFREE(expt); 126 XFREE(expt);
127 XFREE(skey); 127 XFREE(skey);
128 128
129 mp_clear(g_pub); 129 mp_clear(g_pub);
130 130
131 return err; 131 return err;
132 } 132 }
133 133
134 #endif 134 #endif
135 135
136 /* $Source$ */ 136 /* ref: $Format:%D$ */
137 /* $Revision$ */ 137 /* git commit: $Format:%H$ */
138 /* $Date$ */ 138 /* commit time: $Format:%ai$ */
139 139