adding SHA-2 (now complete) in C

[avr-crypto-lib.git] / sha2 / sha256.c

diff --git a/sha2/sha256.c b/sha2/sha256.c
new file mode 100644 (file)
index 0000000..61a9f8e
--- /dev/null
+++ b/sha2/sha256.c
@@ -0,0 +1,128 @@
+/* sha256.c */
+/*
+    This file is part of the ARM-Crypto-Lib.
+    Copyright (C) 2006-2010  Daniel Otte (daniel.otte@rub.de)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * \file               sha256.c
+ * \author             Daniel Otte
+ * \date               16.05.2006
+ *
+ * \par License:
+ *     GPL
+ *
+ * \brief SHA-256 implementation.
+ *
+ *
+ */
+
+#include <stdint.h>
+#include <string.h> /* for memcpy, memmove, memset */
+#include <avr/pgmspace.h>
+#include "sha2_small_common.h"
+#include "sha256.h"
+
+#define LITTLE_ENDIAN
+
+#if defined LITTLE_ENDIAN
+#elif defined BIG_ENDIAN
+#else
+       #error specify endianess!!!
+#endif
+
+
+/*************************************************************************/
+
+const
+uint32_t sha256_init_vector[] PROGMEM = {
+       0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A,
+    0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19 };
+
+
+/*************************************************************************/
+
+/**
+ * \brief \c sh256_init initialises a sha256 context for hashing.
+ * \c sh256_init c initialises the given sha256 context for hashing
+ * @param state pointer to a sha256 context
+ * @return none
+ */
+void sha256_init(sha256_ctx_t *state){
+       state->length=0;
+       memcpy_P(state->h, sha256_init_vector, 8*4);
+}
+
+/*************************************************************************/
+void sha256_nextBlock (sha256_ctx_t *state, const void* block){
+       sha2_small_common_nextBlock(state, block);
+}
+
+/*************************************************************************/
+void sha256_lastBlock (sha256_ctx_t *state, const void* block, uint16_t length_b){
+       sha2_small_common_lastBlock(state, block, length_b);
+}
+/*************************************************************************/
+
+/**
+ * \brief function to process the last block being hashed
+ * @param state Pointer to the context in which this block should be processed.
+ * @param block Pointer to the message wich should be hashed.
+ * @param length is the length of only THIS block in BITS not in bytes!
+ *  bits are big endian, meaning high bits come first.
+ *     if you have a message with bits at the end, the byte must be padded with zeros
+ */
+
+/*************************************************************************/
+
+/*
+ * length in bits!
+ */
+void sha256(void* dest, const void* msg, uint32_t length_b){ /* length could be choosen longer but this is for µC */
+       sha256_ctx_t s;
+       sha256_init(&s);
+       while(length_b >= SHA256_BLOCK_BITS){
+               sha256_nextBlock(&s, msg);
+               msg = (uint8_t*)msg + SHA256_BLOCK_BITS/8;
+               length_b -= SHA256_BLOCK_BITS;
+       }
+       sha256_lastBlock(&s, msg, length_b);
+       sha256_ctx2hash(dest,&s);
+}
+
+
+
+/*************************************************************************/
+
+void sha256_ctx2hash(void* dest, const sha256_ctx_t *state){
+#if defined LITTLE_ENDIAN
+       uint8_t i, j, *s=(uint8_t*)(state->h);
+       i=8;
+       do{
+               j=3;
+               do{
+                       *((uint8_t*)dest) = s[j];
+                       dest = (uint8_t*)dest + 1;
+               }while(j--);
+               s += 4;
+       }while(--i);
+#elif BIG_ENDIAN
+       memcpy(dest, state->h, 32);
+#else
+# error unsupported endian type!
+#endif
+}
+
+