X-Git-Url: https://git.cryptolib.org/?a=blobdiff_plain;f=sha256.h;h=24960a3a43d9325d3cbb01ea15c4f2a7e6b31684;hb=84f2f6e7530dcf41cda0c598019d600bd908b79f;hp=80970ff3a9f03cf1bbc02ff24f8424a8947728e9;hpb=3c995d0a8faeb9d37927d48e20fc45d839e066ea;p=avr-crypto-lib.git
diff --git a/sha256.h b/sha256.h
index 80970ff..24960a3 100644
--- a/sha256.h
+++ b/sha256.h
@@ -1,8 +1,26 @@
+/* sha256.h */
+/*
+ This file is part of the AVR-Crypto-Lib.
+ Copyright (C) 2008 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 .
+*/
/**
- * File: sha256.h
- * Author: Daniel Otte
- * Date: 16.05.2006
- * License: GPL
+ * \file sha256.h
+ * \author Daniel Otte
+ * \date 2006-05-16
+ * \license GPLv3 or later
*
*/
@@ -14,24 +32,91 @@
#include
+/** \def SHA256_HASH_BITS
+ * defines the size of a SHA-256 hash value in bits
+ */
+
+/** \def SHA256_HASH_BYTES
+ * defines the size of a SHA-256 hash value in bytes
+ */
+
+/** \def SHA256_BLOCK_BITS
+ * defines the size of a SHA-256 input block in bits
+ */
+
+/** \def SHA256_BLOCK_BYTES
+ * defines the size of a SHA-256 input block in bytes
+ */
#define SHA256_HASH_BITS 256
+#define SHA256_HASH_BYTES (SHA256_HASH_BITS/8)
#define SHA256_BLOCK_BITS 512
+#define SHA256_BLOCK_BYTES (SHA256_BLOCK_BITS/8)
+/** \typedef sha256_ctx_t
+ * \brief SHA-256 context type
+ *
+ * A variable of this type may hold the state of a SHA-256 hashing process
+ */
typedef struct {
uint32_t h[8];
uint64_t length;
} sha256_ctx_t;
-typedef uint8_t sha256_hash_t[SHA256_HASH_BITS/8];
+/** \typedef sha256_hash_t
+ * \brief SHA-256 hash value type
+ *
+ * A variable of this type may hold the hash value produced by the
+ * sha256_ctx2hash(sha256_hash_t* dest, const sha256_ctx_t* state) function.
+ */
+typedef uint8_t sha256_hash_t[SHA256_HASH_BYTES];
+/** \fn void sha256_init(sha256_ctx_t *state)
+ * \brief initialise a SHA-256 context
+ *
+ * This function sets a ::sha256_ctx_t to the initial values for hashing.
+ * \param state pointer to the SHA-256 hashing context
+ */
void sha256_init(sha256_ctx_t *state);
-void sha256_nextBlock (sha256_ctx_t *state, void* block);
-void sha256_lastBlock(sha256_ctx_t *state, void* block, uint16_t length);
-void sha256_ctx2hash(sha256_hash_t *dest, sha256_ctx_t *state);
-void sha256(sha256_hash_t *dest, void* msg, uint32_t length);
-uint32_t change_endian32(uint32_t x);
+/** \fn void sha256_nextBlock (sha256_ctx_t* state, const void* block)
+ * \brief update the context with a given block
+ *
+ * This function updates the SHA-256 hash context by processing the given block
+ * of fixed length.
+ * \param state pointer to the SHA-256 hash context
+ * \param block pointer to the block of fixed length (512 bit = 64 byte)
+ */
+void sha256_nextBlock (sha256_ctx_t* state, const void* block);
+
+/** \fn void sha256_lastBlock(sha256_ctx_t* state, const void* block, uint16_t length_b)
+ * \brief finalize the context with the given block
+ *
+ * This function finalizes the SHA-256 hash context by processing the given block
+ * of variable length.
+ * \param state pointer to the SHA-256 hash context
+ * \param block pointer to the block of fixed length (512 bit = 64 byte)
+ * \param length_b the length of the block in bits
+ */
+void sha256_lastBlock(sha256_ctx_t* state, const void* block, uint16_t length_b);
+
+/** \fn void sha256_ctx2hash(sha256_hash_t* dest, const sha256_ctx_t* state)
+ * \brief convert the hash state into the hash value
+ * This function reads the context and writes the hash value to the destination
+ * \param dest pointer to the location where the hash value should be written
+ * \param state pointer to the SHA-256 hash context
+ */
+void sha256_ctx2hash(sha256_hash_t* dest, const sha256_ctx_t* state);
+/** \fn void sha256(sha256_hash_t* dest, const void* msg, uint32_t length_b)
+ * \brief simple SHA-256 hashing function for direct hashing
+ *
+ * This function automaticaly hashes a given message of arbitary length with
+ * the SHA-256 hashing algorithm.
+ * \param dest pointer to the location where the hash value is going to be written to
+ * \param msg pointer to the message thats going to be hashed
+ * \param length_b length of the message in bits
+ */
+void sha256(sha256_hash_t* dest, const void* msg, uint32_t length_b);
#endif /*SHA256_H_*/