diff options
Diffstat (limited to 'core/lib/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c')
| -rw-r--r-- | core/lib/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c b/core/lib/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c new file mode 100644 index 0000000..336ef86 --- /dev/null +++ b/core/lib/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c @@ -0,0 +1,107 @@ +/* + * 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_done_decrypt.c + OCB implementation, terminate decryption, by Tom St Denis +*/ +#include "tomcrypt.h" + +#ifdef LTC_OCB_MODE + +/** + Terminate a decrypting OCB state + @param ocb The OCB state + @param ct The ciphertext (if any) + @param ctlen The length of the ciphertext (octets) + @param pt [out] The plaintext + @param tag The authentication tag (to compare against) + @param taglen The length of the authentication tag provided + @param stat [out] The result of the tag comparison + @return CRYPT_OK if the process was successful regardless if the tag is valid +*/ +int ocb_done_decrypt(ocb_state *ocb, + const unsigned char *ct, unsigned long ctlen, + unsigned char *pt, + const unsigned char *tag, unsigned long taglen, int *stat) +{ + int err; + unsigned char *tagbuf; + unsigned long tagbuflen; + + LTC_ARGCHK(ocb != NULL); + LTC_ARGCHK(pt != NULL); + LTC_ARGCHK(ct != NULL); + LTC_ARGCHK(tag != NULL); + LTC_ARGCHK(stat != NULL); + + /* default to failed */ + *stat = 0; + + /* allocate memory */ + tagbuf = XMALLOC(MAXBLOCKSIZE); + if (tagbuf == NULL) { + return CRYPT_MEM; + } + + tagbuflen = MAXBLOCKSIZE; + if ((err = s_ocb_done(ocb, ct, ctlen, pt, tagbuf, &tagbuflen, 1)) != CRYPT_OK) { + goto LBL_ERR; + } + + if (taglen <= tagbuflen && XMEMCMP(tagbuf, tag, taglen) == 0) { + *stat = 1; + } + + err = CRYPT_OK; +LBL_ERR: +#ifdef LTC_CLEAN_STACK + zeromem(tagbuf, MAXBLOCKSIZE); +#endif + + XFREE(tagbuf); + + return err; +} + +#endif + + +/* $Source: /cvs/libtom/libtomcrypt/src/encauth/ocb/ocb_done_decrypt.c,v $ */ +/* $Revision: 1.7 $ */ +/* $Date: 2007/05/12 14:32:35 $ */ |