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 #include <stdarg.h> 13 14 /** 15 @file hmac_memory_multi.c 16 HMAC support, process multiple blocks of memory, Tom St Denis/Dobes Vandermeer 17 */ 18 19 #ifdef LTC_HMAC 20 21 /** 22 HMAC multiple blocks of memory to produce the authentication tag 23 @param hash The index of the hash to use 24 @param key The secret key 25 @param keylen The length of the secret key (octets) 26 @param out [out] Destination of the authentication tag 27 @param outlen [in/out] Max size and resulting size of authentication tag 28 @param in The data to HMAC 29 @param inlen The length of the data to HMAC (octets) 30 @param ... tuples of (data,len) pairs to HMAC, terminated with a (NULL,x) (x=don't care) 31 @return CRYPT_OK if successful 32 */ 33 int hmac_memory_multi(int hash, 34 const unsigned char *key, unsigned long keylen, 35 unsigned char *out, unsigned long *outlen, 36 const unsigned char *in, unsigned long inlen, ...) 37 38 { 39 hmac_state *hmac; 40 int err; 41 va_list args; 42 const unsigned char *curptr; 43 unsigned long curlen; 44 45 LTC_ARGCHK(key != NULL); 46 LTC_ARGCHK(in != NULL); 47 LTC_ARGCHK(out != NULL); 48 LTC_ARGCHK(outlen != NULL); 49 50 /* allocate ram for hmac state */ 51 hmac = XMALLOC(sizeof(hmac_state)); 52 if (hmac == NULL) { 53 return CRYPT_MEM; 54 } 55 56 if ((err = hmac_init(hmac, hash, key, keylen)) != CRYPT_OK) { 57 goto LBL_ERR; 58 } 59 60 va_start(args, inlen); 61 curptr = in; 62 curlen = inlen; 63 for (;;) { 64 /* process buf */ 65 if ((err = hmac_process(hmac, curptr, curlen)) != CRYPT_OK) { 66 goto LBL_ERR; 67 } 68 /* step to next */ 69 curptr = va_arg(args, const unsigned char*); 70 if (curptr == NULL) { 71 break; 72 } 73 curlen = va_arg(args, unsigned long); 74 } 75 if ((err = hmac_done(hmac, out, outlen)) != CRYPT_OK) { 76 goto LBL_ERR; 77 } 78 LBL_ERR: 79 #ifdef LTC_CLEAN_STACK 80 zeromem(hmac, sizeof(hmac_state)); 81 #endif 82 XFREE(hmac); 83 va_end(args); 84 return err; 85 } 86 87 #endif 88 89 90 /* $Source: /cvs/libtom/libtomcrypt/src/mac/hmac/hmac_memory_multi.c,v $ */ 91 /* $Revision: 1.5 $ */ 92 /* $Date: 2006/11/03 00:39:49 $ */ 93
