diff options
Diffstat (limited to 'core/lib/libtomcrypt/src/encauth/ocb/ocb_encrypt.c')
-rw-r--r-- | core/lib/libtomcrypt/src/encauth/ocb/ocb_encrypt.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/encauth/ocb/ocb_encrypt.c b/core/lib/libtomcrypt/src/encauth/ocb/ocb_encrypt.c new file mode 100644 index 0000000..bce2af7 --- /dev/null +++ b/core/lib/libtomcrypt/src/encauth/ocb/ocb_encrypt.c @@ -0,0 +1,99 @@ +/* + * 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 + */ + +/** + @file ocb_encrypt.c + OCB implementation, encrypt data, by Tom St Denis +*/ +#include "tomcrypt.h" + +#ifdef LTC_OCB_MODE + +/** + Encrypt a block of data with OCB. + @param ocb The OCB state + @param pt The plaintext (length of the block size of the block cipher) + @param ct [out] The ciphertext (same size as the pt) + @return CRYPT_OK if successful +*/ +int ocb_encrypt(ocb_state *ocb, const unsigned char *pt, unsigned char *ct) +{ + unsigned char Z[MAXBLOCKSIZE], tmp[MAXBLOCKSIZE]; + int err, x; + + LTC_ARGCHK(ocb != NULL); + LTC_ARGCHK(pt != NULL); + LTC_ARGCHK(ct != NULL); + if ((err = cipher_is_valid(ocb->cipher)) != CRYPT_OK) { + return err; + } + if (ocb->block_len != cipher_descriptor[ocb->cipher].block_length) { + return CRYPT_INVALID_ARG; + } + + /* compute checksum */ + for (x = 0; x < ocb->block_len; x++) { + ocb->checksum[x] ^= pt[x]; + } + + /* Get Z[i] value */ + ocb_shift_xor(ocb, Z); + + /* xor pt in, encrypt, xor Z out */ + for (x = 0; x < ocb->block_len; x++) { + tmp[x] = pt[x] ^ Z[x]; + } + if ((err = cipher_descriptor[ocb->cipher].ecb_encrypt(tmp, ct, &ocb->key)) != CRYPT_OK) { + return err; + } + for (x = 0; x < ocb->block_len; x++) { + ct[x] ^= Z[x]; + } + +#ifdef LTC_CLEAN_STACK + zeromem(Z, sizeof(Z)); + zeromem(tmp, sizeof(tmp)); +#endif + return CRYPT_OK; +} + +#endif + +/* $Source: /cvs/libtom/libtomcrypt/src/encauth/ocb/ocb_encrypt.c,v $ */ +/* $Revision: 1.7 $ */ +/* $Date: 2007/05/12 14:32:35 $ */ |