94 lines
3.6 KiB
C
94 lines
3.6 KiB
C
|
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
|
||
|
|
* project 2005.
|
||
|
|
*/
|
||
|
|
/* ====================================================================
|
||
|
|
* Copyright (c) 2005 The OpenSSL Project. 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.
|
||
|
|
*
|
||
|
|
* 3. All advertising materials mentioning features or use of this
|
||
|
|
* software must display the following acknowledgment:
|
||
|
|
* "This product includes software developed by the OpenSSL Project
|
||
|
|
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
|
||
|
|
*
|
||
|
|
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
|
||
|
|
* endorse or promote products derived from this software without
|
||
|
|
* prior written permission. For written permission, please contact
|
||
|
|
* licensing@OpenSSL.org.
|
||
|
|
*
|
||
|
|
* 5. Products derived from this software may not be called "OpenSSL"
|
||
|
|
* nor may "OpenSSL" appear in their names without prior written
|
||
|
|
* permission of the OpenSSL Project.
|
||
|
|
*
|
||
|
|
* 6. Redistributions of any form whatsoever must retain the following
|
||
|
|
* acknowledgment:
|
||
|
|
* "This product includes software developed by the OpenSSL Project
|
||
|
|
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
|
||
|
|
* EXPRESSED 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 OpenSSL PROJECT OR
|
||
|
|
* ITS 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.
|
||
|
|
* ====================================================================
|
||
|
|
*
|
||
|
|
* This product includes cryptographic software written by Eric Young
|
||
|
|
* (eay@cryptsoft.com). This product includes software written by Tim
|
||
|
|
* Hudson (tjh@cryptsoft.com). */
|
||
|
|
|
||
|
|
#include "../../internal.h"
|
||
|
|
|
||
|
|
#include <ring-core/mem.h>
|
||
|
|
|
||
|
|
int RSA_padding_check_oaep(size_t *out_len, uint8_t y, const uint8_t db[],
|
||
|
|
size_t dblen, const uint8_t phash[],
|
||
|
|
size_t mdlen) {
|
||
|
|
crypto_word bad = ~constant_time_is_zero_w(OPENSSL_memcmp(db, phash, mdlen));
|
||
|
|
bad |= ~constant_time_is_zero_w(y);
|
||
|
|
|
||
|
|
crypto_word looking_for_one_byte = CONSTTIME_TRUE_W;
|
||
|
|
size_t one_index = 0;
|
||
|
|
for (size_t i = mdlen; i < dblen; i++) {
|
||
|
|
crypto_word equals1 = constant_time_eq_w(db[i], 1);
|
||
|
|
crypto_word equals0 = constant_time_eq_w(db[i], 0);
|
||
|
|
one_index =
|
||
|
|
constant_time_select_w(looking_for_one_byte & equals1, i, one_index);
|
||
|
|
looking_for_one_byte =
|
||
|
|
constant_time_select_w(equals1, 0, looking_for_one_byte);
|
||
|
|
bad |= looking_for_one_byte & ~equals0;
|
||
|
|
}
|
||
|
|
|
||
|
|
bad |= looking_for_one_byte;
|
||
|
|
|
||
|
|
if (bad) {
|
||
|
|
goto decoding_err;
|
||
|
|
}
|
||
|
|
|
||
|
|
one_index++;
|
||
|
|
size_t mlen = dblen - one_index;
|
||
|
|
|
||
|
|
*out_len = mlen;
|
||
|
|
|
||
|
|
return 1;
|
||
|
|
|
||
|
|
decoding_err:
|
||
|
|
return 0;
|
||
|
|
}
|