cpan/Digest-SHA/src/hmac.c

   1 /*
   2  * hmac.c: routines to compute HMAC-SHA-1/224/256/384/512 digests
   3  *
   4  * Ref: FIPS PUB 198 The Keyed-Hash Message Authentication Code
   5  *
   6  * Copyright (C) 2003-2011 Mark Shelor, All Rights Reserved
   7  *
   8  * Version: 5.61
   9  * Wed Mar  9 05:26:36 MST 2011
  10  *
  11  */
  12
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include "hmac.h"
  17 #include "sha.h"
  18
  19 /* hmacopen: creates a new HMAC-SHA digest object */
  20 HMAC *hmacopen(int alg, unsigned char *key, unsigned int keylen)
  21 {
  22         unsigned int i;
  23         HMAC *h;
  24
  25         SHA_newz(0, h, 1, HMAC);
  26         if (h == NULL)
  27                 return(NULL);
  28         if ((h->isha = shaopen(alg)) == NULL) {
  29                 SHA_free(h);
  30                 return(NULL);
  31         }
  32         if ((h->osha = shaopen(alg)) == NULL) {
  33                 shaclose(h->isha);
  34                 SHA_free(h);
  35                 return(NULL);
  36         }
  37         if (keylen <= h->osha->blocksize / 8)
  38                 memcpy(h->key, key, keylen);
  39         else {
  40                 if ((h->ksha = shaopen(alg)) == NULL) {
  41                         shaclose(h->isha);
  42                         shaclose(h->osha);
  43                         SHA_free(h);
  44                         return(NULL);
  45                 }
  46                 shawrite(key, keylen * 8, h->ksha);
  47                 shafinish(h->ksha);
  48                 memcpy(h->key, shadigest(h->ksha), h->ksha->digestlen);
  49                 shaclose(h->ksha);
  50         }
  51         for (i = 0; i < h->osha->blocksize / 8; i++)
  52                 h->key[i] ^= 0x5c;
  53         shawrite(h->key, h->osha->blocksize, h->osha);
  54         for (i = 0; i < h->isha->blocksize / 8; i++)
  55                 h->key[i] ^= (0x5c ^ 0x36);
  56         shawrite(h->key, h->isha->blocksize, h->isha);
  57         memset(h->key, 0, sizeof(h->key));
  58         return(h);
  59 }
  60
  61 /* hmacwrite: triggers a state update using data in bitstr/bitcnt */
  62 unsigned long hmacwrite(unsigned char *bitstr, unsigned long bitcnt, HMAC *h)
  63 {
  64         return(shawrite(bitstr, bitcnt, h->isha));
  65 }
  66
  67 /* hmacfinish: computes final digest state */
  68 void hmacfinish(HMAC *h)
  69 {
  70         shafinish(h->isha);
  71         shawrite(shadigest(h->isha), h->isha->digestlen * 8, h->osha);
  72         shaclose(h->isha);
  73         shafinish(h->osha);
  74 }
  75
  76 /* hmacdigest: returns pointer to digest (binary) */
  77 unsigned char *hmacdigest(HMAC *h)
  78 {
  79         return(shadigest(h->osha));
  80 }
  81
  82 /* hmachex: returns pointer to digest (hexadecimal) */
  83 char *hmachex(HMAC *h)
  84 {
  85         return(shahex(h->osha));
  86 }
  87
  88 /* hmacbase64: returns pointer to digest (Base 64) */
  89 char *hmacbase64(HMAC *h)
  90 {
  91         return(shabase64(h->osha));
  92 }
  93
  94 /* hmacclose: de-allocates digest object */
  95 int hmacclose(HMAC *h)
  96 {
  97         if (h != NULL) {
  98                 shaclose(h->osha);
  99                 memset(h, 0, sizeof(HMAC));
 100                 SHA_free(h);
 101         }
 102         return(0);
 103 }