Files
pcp/libpcp/mac.c
2013-11-04 17:43:22 +01:00

77 lines
2.2 KiB
C

/*
This file is part of Pretty Curved Privacy (pcp1).
Copyright (C) 2013 T.Linden.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
You can contact me by mail: <tlinden AT cpan DOT org>.
*/
#include "mac.h"
size_t pcp_sodium_mac(unsigned char **cipher,
unsigned char *cleartext,
size_t clearsize,
unsigned char *nonce,
unsigned char *key) {
unsigned char *pad_clear;
unsigned char *pad_cipher;
pad_cipher = ucmalloc(crypto_secretbox_ZEROBYTES + clearsize);
pcp_pad_prepend(&pad_clear, cleartext, crypto_secretbox_ZEROBYTES, clearsize);
crypto_secretbox(pad_cipher, pad_clear,
clearsize + crypto_secretbox_ZEROBYTES, nonce, key);
pcp_pad_remove(cipher, pad_cipher, crypto_secretbox_BOXZEROBYTES,
(clearsize + crypto_secretbox_ZEROBYTES) - crypto_secretbox_BOXZEROBYTES);
free(pad_clear);
free(pad_cipher);
return (clearsize + crypto_secretbox_ZEROBYTES) - crypto_secretbox_BOXZEROBYTES;
}
int pcp_sodium_verify_mac(unsigned char **cleartext, unsigned char* message,
size_t messagesize, unsigned char *nonce,
unsigned char *key) {
// verify the mac
unsigned char *pad_cipher;
unsigned char *pad_clear;
int success = -1;
pcp_pad_prepend(&pad_cipher, message, crypto_secretbox_BOXZEROBYTES, messagesize);
pad_clear = (unsigned char *)ucmalloc((crypto_secretbox_BOXZEROBYTES + messagesize));
if (crypto_secretbox_open(pad_clear,
pad_cipher,
messagesize + crypto_secretbox_BOXZEROBYTES,
nonce, key) == 0) {
success = 0;
}
pcp_pad_remove(cleartext, pad_clear, crypto_secretbox_ZEROBYTES, messagesize);
free(pad_clear);
free(pad_cipher);
return success;
}