| /* |
| Copyright (C) 2006-2013 Werner Dittmann |
| |
| This program is free software: you can redistribute it and/or modify |
| it under the terms of the GNU Lesser 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/>. |
| */ |
| |
| /** |
| * Functions to compute SHA256 digest. |
| * |
| * @author: Werner Dittmann <Werner.Dittmann@t-online.de> |
| */ |
| |
| #ifndef _SHA256_H |
| #define _SHA256_H |
| |
| /** |
| * @file sha256.h |
| * @brief Function that provide SHA256 support |
| * |
| * @ingroup GNU_ZRTP |
| * @{ |
| */ |
| |
| #include <stdint.h> |
| |
| #ifndef SHA256_DIGEST_LENGTH |
| #define SHA256_DIGEST_LENGTH 32 |
| #endif |
| |
| /** |
| * Compute SHA256 digest. |
| * |
| * This functions takes one data chunk and computes its SHA256 digest. This |
| * function creates and deletes an own SHA256 context to perform the SHA256 |
| * operations. |
| * |
| * @param data |
| * Points to the data chunk. |
| * @param data_length |
| * Length of the data in bytes |
| * @param digest |
| * Points to a buffer that receives the computed digest. This |
| * buffer must have a size of at least 32 bytes (SHA256_DIGEST_LENGTH). |
| */ |
| void sha256(unsigned char *data, |
| unsigned int data_length, |
| unsigned char *digest); |
| |
| /** |
| * Compute SHA256 digest over several data cunks. |
| * |
| * This functions takes several data chunks and computes the SHA256 digest. |
| * This function creates and deletes an own SHA256 context to perform the |
| * SHA256 operations. |
| * |
| * @param data |
| * Points to an array of pointers that point to the data chunks. A NULL |
| * pointer in an array element terminates the data chunks. |
| * @param data_length |
| * Points to an array of integers that hold the length of each data chunk. |
| * @param digest |
| * Points to a buffer that receives the computed digest. This |
| * buffer must have a size of at least 32 bytes (SHA256_DIGEST_LENGTH). |
| */ |
| void sha256(unsigned char *data[], |
| unsigned int data_length[], |
| unsigned char *digest); |
| /** |
| * Create and initialize a SHA256 context. |
| * |
| * An application uses this context to hash several data into one SHA256 |
| * digest. See also sha256Ctx(...) and closeSha256Context(...). |
| * |
| * @return Returns a pointer to the initialized SHA256 context |
| */ |
| void* createSha256Context(); |
| |
| /** |
| * Compute a digest and close the SHa256 digest. |
| * |
| * An application uses this function to compute the SHA256 digest and to |
| * close the SHA256 context. |
| * |
| * @param ctx |
| * Points to the SHA256 context. |
| * @param digest |
| * If this pointer is not NULL then it must point to a byte array that |
| * is big enough to hold the SHA256 digest (256 bit = 32 Bytes). If this |
| * pointer is NULL then the functions does not compute the digest but |
| * closes the context only. The context cannot be used anymore. |
| */ |
| void closeSha256Context(void* ctx, |
| unsigned char* digest); |
| |
| /** |
| * Update the SHA256 context with data. |
| * |
| * This functions updates the SHA256 context with some data. |
| * See also CloseSha256Context(...) how to get the digest. |
| * |
| * @param ctx |
| * Points to the SHA256 context. |
| * @param data |
| * Points to the data to update the context. |
| * @param dataLength |
| * The length of the data in bytes. |
| */ |
| void sha256Ctx(void* ctx, unsigned char* data, |
| unsigned int dataLength); |
| |
| /** |
| * Update the SHA256 context with several data chunks. |
| * |
| * This functions updates the SHA256 context with some data. |
| * See also CloseSha256Context(...) how to get the digest. |
| * |
| * @param ctx |
| * Points to the SHA256 context. |
| * @param dataChunks |
| * Points to an array of pointers that point to the data chunks. A NULL |
| * pointer in an array element terminates the data chunks. |
| * @param dataChunkLength |
| * Points to an array of integers that hold the length of each data chunk. |
| * |
| */ |
| void sha256Ctx(void* ctx, unsigned char* dataChunks[], |
| unsigned int dataChunkLength[]); |
| |
| /** |
| * @} |
| */ |
| #endif |
| |