chacha.h

00001 /* chacha.h
00002  *
00003  * Copyright (C) 2006-2016 wolfSSL Inc.
00004  *
00005  * This file is part of wolfSSL.
00006  *
00007  * wolfSSL is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 2 of the License, or
00010  * (at your option) any later version.
00011  *
00012  * wolfSSL is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with this program; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
00020  */
00021 
00022 
00023 #ifndef WOLF_CRYPT_CHACHA_H
00024 #define WOLF_CRYPT_CHACHA_H
00025 
00026 #include <wolfssl/wolfcrypt/types.h>
00027 
00028 #ifdef HAVE_CHACHA
00029 
00030 #ifdef __cplusplus
00031     extern "C" {
00032 #endif
00033 
00034 /* Size of the IV */
00035 #define CHACHA_IV_WORDS    3
00036 #define CHACHA_IV_BYTES    (CHACHA_IV_WORDS * sizeof(word32))
00037 
00038 /* Size of ChaCha chunks */
00039 #define CHACHA_CHUNK_WORDS 16
00040 #define CHACHA_CHUNK_BYTES (CHACHA_CHUNK_WORDS * sizeof(word32))
00041 
00042 enum {
00043     CHACHA_ENC_TYPE = 7     /* cipher unique type */
00044 };
00045 
00046 typedef struct ChaCha {
00047     word32 X[CHACHA_CHUNK_WORDS];           /* state of cipher */
00048 } ChaCha;
00049 
00050 /**
00051   * IV(nonce) changes with each record
00052   * counter is for what value the block counter should start ... usually 0
00053   */
00054 WOLFSSL_API int wc_Chacha_SetIV(ChaCha* ctx, const byte* inIv, word32 counter);
00055 
00056 WOLFSSL_API int wc_Chacha_Process(ChaCha* ctx, byte* cipher, const byte* plain,
00057                               word32 msglen);
00058 WOLFSSL_API int wc_Chacha_SetKey(ChaCha* ctx, const byte* key, word32 keySz);
00059 
00060 #ifdef __cplusplus
00061     } /* extern "C" */
00062 #endif
00063 
00064 #endif /* HAVE_CHACHA */
00065 #endif /* WOLF_CRYPT_CHACHA_H */
00066 
00067