diff options
Diffstat (limited to 'core/lib/libtomcrypt/src/encauth/ccm/ccm_add_aad.c')
-rw-r--r-- | core/lib/libtomcrypt/src/encauth/ccm/ccm_add_aad.c | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/encauth/ccm/ccm_add_aad.c b/core/lib/libtomcrypt/src/encauth/ccm/ccm_add_aad.c new file mode 100644 index 0000000..03130ea --- /dev/null +++ b/core/lib/libtomcrypt/src/encauth/ccm/ccm_add_aad.c @@ -0,0 +1,89 @@ +/* + * 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 + +/** + Add AAD to the CCM state + @param ccm The CCM state + @param adata The additional authentication data to add to the CCM state + @param adatalen The length of the AAD data. + @return CRYPT_OK on success + */ +int ccm_add_aad(ccm_state *ccm, + const unsigned char *adata, unsigned long adatalen) +{ + unsigned long y; + int err; + + LTC_ARGCHK(ccm != NULL); + LTC_ARGCHK(adata != NULL); + + if (ccm->aadlen < ccm->current_aadlen + adatalen) { + return CRYPT_INVALID_ARG; + } + ccm->current_aadlen += adatalen; + + /* now add the data */ + for (y = 0; y < adatalen; y++) { + if (ccm->x == 16) { + /* full block so let's encrypt it */ + if ((err = cipher_descriptor[ccm->cipher]->ecb_encrypt(ccm->PAD, ccm->PAD, &ccm->K)) != CRYPT_OK) { + return CRYPT_ERROR; + } + ccm->x = 0; + } + ccm->PAD[ccm->x++] ^= adata[y]; + } + + /* remainder? */ + if (ccm->aadlen == ccm->current_aadlen) { + if (ccm->x != 0) { + if ((err = cipher_descriptor[ccm->cipher]->ecb_encrypt(ccm->PAD, ccm->PAD, &ccm->K)) != CRYPT_OK) { + return CRYPT_ERROR; + } + } + ccm->x = 0; + } + + return CRYPT_OK; +} + +#endif |