changing hmac API + bug fixes

[avr-crypto-lib.git] / hmac-sha256.c

diff --git a/hmac-sha256.c b/hmac-sha256.c
index 148fc7d927519b746c9bfff6c5bbcbc1c8503d7b..6a5718906b2d6fd5aa3899f33880cf06c74d99fc 100644 (file)
--- a/hmac-sha256.c
+++ b/hmac-sha256.c
@@ -32,80 +32,73 @@
 #include <string.h>
 #include "config.h"
 #include "sha256.h"
+#include "hmac-sha256.h"
 
 #define IPAD 0x36
 #define OPAD 0x5C
 
-typedef sha256_ctx_t hmac_sha256_ctx_t;
+#ifndef HMAC_SHA256_SHORTONLY
 
-#ifndef HMAC_SHORTONLY
-
-void hmac_sha256_init(hmac_sha256_ctx_t *s, void* key, uint16_t keylength_b){
-       uint8_t buffer[SHA256_HASH_BYTES];
+void hmac_sha256_init(hmac_sha256_ctx_t *s, const void* key, uint16_t keylength_b){
+       uint8_t buffer[HMAC_SHA256_BLOCK_BYTES];
        uint8_t i;
        
-       memset(buffer, 0, SHA256_HASH_BYTES);
-       if (keylength_b > SHA256_BLOCK_BITS){
+       memset(buffer, 0, HMAC_SHA256_BLOCK_BYTES);
+       if (keylength_b > HMAC_SHA256_BLOCK_BITS){
                sha256((void*)buffer, key, keylength_b);
        } else {
                memcpy(buffer, key, (keylength_b+7)/8);
        }
        
-       for (i=0; i<SHA256_HASH_BYTES; ++i){
+       for (i=0; i<HMAC_SHA256_BLOCK_BYTES; ++i){
                buffer[i] ^= IPAD;
        }
        
-       sha256_init(s);
-       sha256_nextBlock(s, buffer);
+       sha256_init(&(s->a));
+       sha256_nextBlock(&(s->a), buffer);
+       
+       for (i=0; i<HMAC_SHA256_BLOCK_BYTES; ++i){
+               buffer[i] ^= IPAD^OPAD;
+       }
+       sha256_init(&(s->b));
+       sha256_nextBlock(&(s->b), buffer);
+       
 #if defined SECURE_WIPE_BUFFER
-       memset(buffer, 0, SHA256_HASH_BYTES);
+       memset(buffer, 0, SHA256_BLOCK_BYTES);
 #endif
 }
 
-void hmac_sha256_final(hmac_sha256_ctx_t *s, void* key, uint16_t keylength_b){
-       uint8_t buffer[SHA256_HASH_BYTES];
-       uint8_t i;
-       sha256_ctx_t a;
-       
-       memset(buffer, 0, SHA256_HASH_BYTES);
-       if (keylength_b > SHA256_BLOCK_BITS){
-               sha256((void*)buffer, key, keylength_b);
-       } else {
-               memcpy(buffer, key, (keylength_b+7)/8);
-       }
-       
-       for (i=0; i<SHA256_HASH_BYTES; ++i){
-               buffer[i] ^= OPAD;
+void hmac_sha256_nextBlock(hmac_sha256_ctx_t *s, const void* block){
+       sha256_nextBlock(&(s->a), block);
+}
+
+void hmac_sha256_lastBlock(hmac_sha256_ctx_t *s, const void* block, uint16_t length_b){
+/*     while(length_b>=SHA256_BLOCK_BITS){
+               sha256_nextBlock(&(s->a), block);
+               block = (uint8_t*)block + SHA256_BLOCK_BYTES;
+               length_b -= SHA256_BLOCK_BITS;
        }
-       
-       sha256_init(&a);
-       sha256_nextBlock(&a, buffer); /* hash key ^ opad */
-       sha256_ctx2hash((void*)buffer, s);  /* copy hash(key ^ ipad, msg) to buffer */
-       sha256_lastBlock(&a, buffer, SHA256_HASH_BITS);
-       memcpy(s, &a, sizeof(sha256_ctx_t));
-#if defined SECURE_WIPE_BUFFER
-       memset(buffer, 0, SHA256_HASH_BYTES);
-       memset(a.h, 0, 8*4);
-#endif 
+*/     sha256_lastBlock(&(s->a), block, length_b);
 }
 
-#endif
+void hmac_sha256_final(void* dest, hmac_sha256_ctx_t *s){
+       sha256_ctx2hash((sha256_hash_t*)dest, &(s->a));
+       sha256_lastBlock(&(s->b), dest, SHA256_HASH_BITS);
+       sha256_ctx2hash((sha256_hash_t*)dest, &(s->b));                 
+}
 
-/*
-void hmac_sha256_nextBlock()
-void hmac_sha256_lastBlock()
-*/
+#endif
 
 /*
  * keylength in bits!
  * message length in bits!
  */
-void hmac_sha256(void* dest, void* key, uint16_t keylength_b, void* msg, uint64_t msglength_b){ /* a one-shot*/
+void hmac_sha256(void* dest, const void* key, uint16_t keylength_b, const void* msg, uint32_t msglength_b){ /* a one-shot*/
        sha256_ctx_t s;
        uint8_t i;
-       uint8_t buffer[SHA256_HASH_BYTES];
+       uint8_t buffer[HMAC_SHA256_BLOCK_BYTES];
        
-       memset(buffer, 0, SHA256_HASH_BYTES);
+       memset(buffer, 0, HMAC_SHA256_BLOCK_BYTES);
        
        /* if key is larger than a block we have to hash it*/
        if (keylength_b > SHA256_BLOCK_BITS){
@@ -114,19 +107,19 @@ void hmac_sha256(void* dest, void* key, uint16_t keylength_b, void* msg, uint64_
                memcpy(buffer, key, (keylength_b+7)/8);
        }
        
-       for (i=0; i<SHA256_HASH_BYTES; ++i){
+       for (i=0; i<SHA256_BLOCK_BYTES; ++i){
                buffer[i] ^= IPAD;
        }
        sha256_init(&s);
        sha256_nextBlock(&s, buffer);
-       while (msglength_b >= SHA256_BLOCK_BITS){
+       while (msglength_b >= HMAC_SHA256_BLOCK_BITS){
                sha256_nextBlock(&s, msg);
-               msg = (uint8_t*)msg + SHA256_HASH_BYTES;
-               msglength_b -=  SHA256_BLOCK_BITS;
+               msg = (uint8_t*)msg + HMAC_SHA256_BLOCK_BYTES;
+               msglength_b -=  HMAC_SHA256_BLOCK_BITS;
        }
        sha256_lastBlock(&s, msg, msglength_b);
        /* since buffer still contains key xor ipad we can do ... */
-       for (i=0; i<SHA256_HASH_BYTES; ++i){
+       for (i=0; i<HMAC_SHA256_BLOCK_BYTES; ++i){
                buffer[i] ^= IPAD ^ OPAD;
        }
        sha256_ctx2hash(dest, &s); /* save inner hash temporary to dest */