diff options
Diffstat (limited to 'core/lib/libtomcrypt/src/encauth/ccm/ccm_done.c')
-rw-r--r-- | core/lib/libtomcrypt/src/encauth/ccm/ccm_done.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/encauth/ccm/ccm_done.c b/core/lib/libtomcrypt/src/encauth/ccm/ccm_done.c new file mode 100644 index 0000000..7a4e211 --- /dev/null +++ b/core/lib/libtomcrypt/src/encauth/ccm/ccm_done.c @@ -0,0 +1,91 @@ +/* + * Copyright (c) 2001-2007, Tom St Denis + * Copyright (c) 2014, STMicroelectronics International N.V. + * 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" + +#ifdef LTC_CCM_MODE + +/** + Terminate a CCM stream + @param ccm The CCM state + @param tag [out] The destination for the MAC tag + @param taglen [in/out] The length of the MAC tag + @return CRYPT_OK on success + */ +int ccm_done(ccm_state *ccm, + unsigned char *tag, unsigned long *taglen) +{ + unsigned long x, y; + int err; + + LTC_ARGCHK(ccm != NULL); + + /* Check all data have been processed */ + if (ccm->ptlen != ccm->current_ptlen) { + return CRYPT_ERROR; + } + + LTC_ARGCHK(tag != NULL); + LTC_ARGCHK(taglen != NULL); + + if (ccm->x != 0) { + if ((err = cipher_descriptor[ccm->cipher]->ecb_encrypt(ccm->PAD, ccm->PAD, &ccm->K)) != CRYPT_OK) { + return err; + } + } + + /* setup CTR for the TAG (zero the count) */ + for (y = 15; y > 15 - ccm->L; y--) { + ccm->ctr[y] = 0x00; + } + if ((err = cipher_descriptor[ccm->cipher]->ecb_encrypt(ccm->ctr, ccm->CTRPAD, &ccm->K)) != CRYPT_OK) { + return err; + } + + cipher_descriptor[ccm->cipher]->done(&ccm->K); + + /* store the TAG */ + for (x = 0; x < 16 && x < *taglen; x++) { + tag[x] = ccm->PAD[x] ^ ccm->CTRPAD[x]; + } + *taglen = x; + + return CRYPT_OK; +} + +#endif |