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comparison hmac_init.c @ 143:5d99163f7e32 libtomcrypt-orig

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import of libtomcrypt 0.99
author Matt Johnston <matt@ucc.asn.au>
date Sun, 19 Dec 2004 11:34:45 +0000
parents 7faae8f46238
children
comparison
equal deleted inserted replaced
15:6362d3854bb4 143:5d99163f7e32
33 33
34 #define HMAC_BLOCKSIZE hash_descriptor[hash].blocksize 34 #define HMAC_BLOCKSIZE hash_descriptor[hash].blocksize
35 35
36 int hmac_init(hmac_state *hmac, int hash, const unsigned char *key, unsigned long keylen) 36 int hmac_init(hmac_state *hmac, int hash, const unsigned char *key, unsigned long keylen)
37 { 37 {
38 unsigned char buf[MAXBLOCKSIZE]; 38 unsigned char *buf;
39 unsigned long hashsize; 39 unsigned long hashsize;
40 unsigned long i, z; 40 unsigned long i, z;
41 int err; 41 int err;
42 42
43 _ARGCHK(hmac != NULL); 43 _ARGCHK(hmac != NULL);
44 _ARGCHK(key != NULL); 44 _ARGCHK(key != NULL);
45 45
46 /* valid hash? */
46 if ((err = hash_is_valid(hash)) != CRYPT_OK) { 47 if ((err = hash_is_valid(hash)) != CRYPT_OK) {
47 return err; 48 return err;
48 } 49 }
50 hmac->hash = hash;
51 hashsize = hash_descriptor[hash].hashsize;
49 52
50 /* valid key length? */ 53 /* valid key length? */
51 if (keylen == 0) { 54 if (keylen == 0) {
52 return CRYPT_INVALID_KEYSIZE; 55 return CRYPT_INVALID_KEYSIZE;
53 } 56 }
54 57
55 hmac->hash = hash; 58 /* allocate ram for buf */
59 buf = XMALLOC(HMAC_BLOCKSIZE);
60 if (buf == NULL) {
61 return CRYPT_MEM;
62 }
56 63
57 // (1) make sure we have a large enough key 64 /* allocate memory for key */
58 hashsize = hash_descriptor[hash].hashsize; 65 hmac->key = XMALLOC(HMAC_BLOCKSIZE);
66 if (hmac->key == NULL) {
67 XFREE(buf);
68 return CRYPT_MEM;
69 }
70
71 /* (1) make sure we have a large enough key */
59 if(keylen > HMAC_BLOCKSIZE) { 72 if(keylen > HMAC_BLOCKSIZE) {
60 z = (unsigned long)sizeof(hmac->key); 73 z = HMAC_BLOCKSIZE;
61 if ((err = hash_memory(hash, key, keylen, hmac->key, &z)) != CRYPT_OK) { 74 if ((err = hash_memory(hash, key, keylen, hmac->key, &z)) != CRYPT_OK) {
62 return err; 75 goto __ERR;
63 } 76 }
64 if(hashsize < HMAC_BLOCKSIZE) { 77 if(hashsize < HMAC_BLOCKSIZE) {
65 zeromem((hmac->key) + hashsize, (size_t)(HMAC_BLOCKSIZE - hashsize)); 78 zeromem((hmac->key) + hashsize, (size_t)(HMAC_BLOCKSIZE - hashsize));
66 } 79 }
67 keylen = hashsize; 80 keylen = hashsize;
68 } else { 81 } else {
69 memcpy(hmac->key, key, (size_t)keylen); 82 XMEMCPY(hmac->key, key, (size_t)keylen);
70 if(keylen < HMAC_BLOCKSIZE) { 83 if(keylen < HMAC_BLOCKSIZE) {
71 zeromem((hmac->key) + keylen, (size_t)(HMAC_BLOCKSIZE - keylen)); 84 zeromem((hmac->key) + keylen, (size_t)(HMAC_BLOCKSIZE - keylen));
72 } 85 }
73 } 86 }
74 87
75 // Create the initial vector for step (3) 88 /* Create the initial vector for step (3) */
76 for(i=0; i < HMAC_BLOCKSIZE; i++) { 89 for(i=0; i < HMAC_BLOCKSIZE; i++) {
77 buf[i] = hmac->key[i] ^ 0x36; 90 buf[i] = hmac->key[i] ^ 0x36;
78 } 91 }
79 92
80 // Pre-pend that to the hash data 93 /* Pre-pend that to the hash data */
81 hash_descriptor[hash].init(&hmac->md); 94 if ((err = hash_descriptor[hash].init(&hmac->md)) != CRYPT_OK) {
82 hash_descriptor[hash].process(&hmac->md, buf, HMAC_BLOCKSIZE); 95 goto __ERR;
96 }
83 97
84 return CRYPT_OK; 98 if ((err = hash_descriptor[hash].process(&hmac->md, buf, HMAC_BLOCKSIZE)) != CRYPT_OK) {
99 goto __ERR;
100 }
101 goto done;
102 __ERR:
103 /* free the key since we failed */
104 XFREE(hmac->key);
105 done:
106 #ifdef CLEAN_STACK
107 zeromem(buf, HMAC_BLOCKSIZE);
108 #endif
109
110 XFREE(buf);
111 return err;
85 } 112 }
86 113
87 #endif 114 #endif