ext/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) 2003-2005 Mark Shelor, All Rights Reserved
   7  *
   8  * Version: 5.32
   9  * Fri Dec  2 02:32:20 MST 2005
  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(alg, key, keylen)
  21 int alg;
  22 unsigned char *key;
  23 unsigned int keylen;
  24 {
  25         unsigned int i;
  26         HMAC *h;
  27
  28         SHA_newz(0, h, 1, HMAC);
  29         if (h == NULL)
  30                 return(NULL);
  31         if ((h->isha = shaopen(alg)) == NULL) {
  32                 SHA_free(h);
  33                 return(NULL);
  34         }
  35         if ((h->osha = shaopen(alg)) == NULL) {
  36                 shaclose(h->isha);
  37                 SHA_free(h);
  38                 return(NULL);
  39         }
  40         if (keylen <= h->osha->blocksize / 8)
  41                 memcpy(h->key, key, keylen);
  42         else {
  43                 if ((h->ksha = shaopen(alg)) == NULL) {
  44                         shaclose(h->isha);
  45                         shaclose(h->osha);
  46                         SHA_free(h);
  47                         return(NULL);
  48                 }
  49                 shawrite(key, keylen * 8, h->ksha);
  50                 shafinish(h->ksha);
  51                 memcpy(h->key, shadigest(h->ksha), h->ksha->digestlen);
  52                 shaclose(h->ksha);
  53         }
  54         for (i = 0; i < h->osha->blocksize / 8; i++)
  55                 h->key[i] ^= 0x5c;
  56         shawrite(h->key, h->osha->blocksize, h->osha);
  57         for (i = 0; i < h->isha->blocksize / 8; i++)
  58                 h->key[i] ^= (0x5c ^ 0x36);
  59         shawrite(h->key, h->isha->blocksize, h->isha);
  60         memset(h->key, 0, sizeof(h->key));
  61         return(h);
  62 }
  63
  64 /* hmacwrite: triggers a state update using data in bitstr/bitcnt */
  65 unsigned long hmacwrite(bitstr, bitcnt, h)
  66 unsigned char *bitstr;
  67 unsigned long bitcnt;
  68 HMAC *h;
  69 {
  70         return(shawrite(bitstr, bitcnt, h->isha));
  71 }
  72
  73 /* hmacfinish: computes final digest state */
  74 void hmacfinish(h)
  75 HMAC *h;
  76 {
  77         shafinish(h->isha);
  78         shawrite(shadigest(h->isha), h->isha->digestlen * 8, h->osha);
  79         shaclose(h->isha);
  80         shafinish(h->osha);
  81 }
  82
  83 /* hmacdigest: returns pointer to digest (binary) */
  84 unsigned char *hmacdigest(h)
  85 HMAC *h;
  86 {
  87         return(shadigest(h->osha));
  88 }
  89
  90 /* hmachex: returns pointer to digest (hexadecimal) */
  91 char *hmachex(h)
  92 HMAC *h;
  93 {
  94         return(shahex(h->osha));
  95 }
  96
  97 /* hmacbase64: returns pointer to digest (Base 64) */
  98 char *hmacbase64(h)
  99 HMAC *h;
 100 {
 101         return(shabase64(h->osha));
 102 }
 103
 104 /* hmacclose: de-allocates digest object */
 105 int hmacclose(h)
 106 HMAC *h;
 107 {
 108         shaclose(h->osha);
 109         if (h != NULL) {
 110                 memset(h, 0, sizeof(HMAC));
 111                 SHA_free(h);
 112         }
 113         return(0);
 114 }