1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis 2 * 3 * LibTomCrypt is a library that provides various cryptographic 4 * algorithms in a highly modular and flexible manner. 5 * 6 * The library is free for all purposes without any express 7 * guarantee it works. 8 * 9 * Tom St Denis, tomstdenis (at) gmail.com, http://libtomcrypt.com 10 */ 11 #include "tomcrypt.h" 12 13 /** 14 @file hmac_memory.c 15 HMAC support, process a block of memory, Tom St Denis/Dobes Vandermeer 16 */ 17 18 #ifdef LTC_HMAC 19 20 /** 21 HMAC a block of memory to produce the authentication tag 22 @param hash The index of the hash to use 23 @param key The secret key 24 @param keylen The length of the secret key (octets) 25 @param in The data to HMAC 26 @param inlen The length of the data to HMAC (octets) 27 @param out [out] Destination of the authentication tag 28 @param outlen [in/out] Max size and resulting size of authentication tag 29 @return CRYPT_OK if successful 30 */ 31 int hmac_memory(int hash, 32 const unsigned char *key, unsigned long keylen, 33 const unsigned char *in, unsigned long inlen, 34 unsigned char *out, unsigned long *outlen) 35 { 36 hmac_state *hmac; 37 int err; 38 39 LTC_ARGCHK(key != NULL); 40 LTC_ARGCHK(in != NULL); 41 LTC_ARGCHK(out != NULL); 42 LTC_ARGCHK(outlen != NULL); 43 44 /* make sure hash descriptor is valid */ 45 if ((err = hash_is_valid(hash)) != CRYPT_OK) { 46 return err; 47 } 48 49 /* is there a descriptor? */ 50 if (hash_descriptor[hash].hmac_block != NULL) { 51 return hash_descriptor[hash].hmac_block(key, keylen, in, inlen, out, outlen); 52 } 53 54 /* nope, so call the hmac functions */ 55 /* allocate ram for hmac state */ 56 hmac = XMALLOC(sizeof(hmac_state)); 57 if (hmac == NULL) { 58 return CRYPT_MEM; 59 } 60 61 if ((err = hmac_init(hmac, hash, key, keylen)) != CRYPT_OK) { 62 goto LBL_ERR; 63 } 64 65 if ((err = hmac_process(hmac, in, inlen)) != CRYPT_OK) { 66 goto LBL_ERR; 67 } 68 69 if ((err = hmac_done(hmac, out, outlen)) != CRYPT_OK) { 70 goto LBL_ERR; 71 } 72 73 err = CRYPT_OK; 74 LBL_ERR: 75 #ifdef LTC_CLEAN_STACK 76 zeromem(hmac, sizeof(hmac_state)); 77 #endif 78 79 XFREE(hmac); 80 return err; 81 } 82 83 #endif 84 85 86 /* $Source: /cvs/libtom/libtomcrypt/src/mac/hmac/hmac_memory.c,v $ */ 87 /* $Revision: 1.6 $ */ 88 /* $Date: 2006/11/03 00:39:49 $ */ 89
