diff options
Diffstat (limited to 'core/lib/libtomcrypt/src/modes/lrw/lrw_process.c')
| -rw-r--r-- | core/lib/libtomcrypt/src/modes/lrw/lrw_process.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/modes/lrw/lrw_process.c b/core/lib/libtomcrypt/src/modes/lrw/lrw_process.c new file mode 100644 index 0000000..8830185 --- /dev/null +++ b/core/lib/libtomcrypt/src/modes/lrw/lrw_process.c @@ -0,0 +1,147 @@ +/* + * Copyright (c) 2001-2007, Tom St Denis + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtom.org + */ +#include "tomcrypt.h" + +/** + @file lrw_process.c + LRW_MODE implementation, Encrypt/decrypt blocks, Tom St Denis +*/ + +#ifdef LTC_LRW_MODE + +/** + Process blocks with LRW, since decrypt/encrypt are largely the same they share this code. + @param pt The "input" data + @param ct [out] The "output" data + @param len The length of the input, must be a multiple of 128-bits (16 octets) + @param mode LRW_ENCRYPT or LRW_DECRYPT + @param lrw The LRW state + @return CRYPT_OK if successful +*/ +int lrw_process(const unsigned char *pt, unsigned char *ct, unsigned long len, int mode, symmetric_LRW *lrw) +{ + unsigned char prod[16]; + int x, err; +#ifdef LTC_LRW_TABLES + int y; +#endif + + LTC_ARGCHK(pt != NULL); + LTC_ARGCHK(ct != NULL); + LTC_ARGCHK(lrw != NULL); + + if (len & 15) { + return CRYPT_INVALID_ARG; + } + + while (len) { + /* copy pad */ + XMEMCPY(prod, lrw->pad, 16); + + /* increment IV */ + for (x = 15; x >= 0; x--) { + lrw->IV[x] = (lrw->IV[x] + 1) & 255; + if (lrw->IV[x]) { + break; + } + } + + /* update pad */ +#ifdef LTC_LRW_TABLES + /* for each byte changed we undo it's affect on the pad then add the new product */ + for (; x < 16; x++) { +#ifdef LTC_FAST + for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) { + *((LTC_FAST_TYPE *)(lrw->pad + y)) ^= *((LTC_FAST_TYPE *)(&lrw->PC[x][lrw->IV[x]][y])) ^ *((LTC_FAST_TYPE *)(&lrw->PC[x][(lrw->IV[x]-1)&255][y])); + } +#else + for (y = 0; y < 16; y++) { + lrw->pad[y] ^= lrw->PC[x][lrw->IV[x]][y] ^ lrw->PC[x][(lrw->IV[x]-1)&255][y]; + } +#endif + } +#else + gcm_gf_mult(lrw->tweak, lrw->IV, lrw->pad); +#endif + + /* xor prod */ +#ifdef LTC_FAST + for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) { + *((LTC_FAST_TYPE *)(ct + x)) = *((LTC_FAST_TYPE *)(pt + x)) ^ *((LTC_FAST_TYPE *)(prod + x)); + } +#else + for (x = 0; x < 16; x++) { + ct[x] = pt[x] ^ prod[x]; + } +#endif + + /* send through cipher */ + if (mode == LRW_ENCRYPT) { + if ((err = cipher_descriptor[lrw->cipher].ecb_encrypt(ct, ct, &lrw->key)) != CRYPT_OK) { + return err; + } + } else { + if ((err = cipher_descriptor[lrw->cipher].ecb_decrypt(ct, ct, &lrw->key)) != CRYPT_OK) { + return err; + } + } + + /* xor prod */ +#ifdef LTC_FAST + for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) { + *((LTC_FAST_TYPE *)(ct + x)) = *((LTC_FAST_TYPE *)(ct + x)) ^ *((LTC_FAST_TYPE *)(prod + x)); + } +#else + for (x = 0; x < 16; x++) { + ct[x] = ct[x] ^ prod[x]; + } +#endif + + /* move to next */ + pt += 16; + ct += 16; + len -= 16; + } + + return CRYPT_OK; +} + +#endif +/* $Source: /cvs/libtom/libtomcrypt/src/modes/lrw/lrw_process.c,v $ */ +/* $Revision: 1.11 $ */ +/* $Date: 2006/12/28 01:27:24 $ */ |