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/*
* Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "inner.h"
/* see bearssl_rsa.h */
uint32_t
br_rsa_ssl_decrypt(br_rsa_private core, const br_rsa_private_key *sk,
unsigned char *data, size_t len)
{
uint32_t x;
size_t u;
/*
* A first check on length. Since this test works only on the
* buffer length, it needs not (and cannot) be constant-time.
*/
if (len < 59 || len != (sk->n_bitlen + 7) >> 3) {
return 0;
}
x = core(data, sk);
x &= EQ(data[0], 0x00);
x &= EQ(data[1], 0x02);
for (u = 2; u < (len - 49); u ++) {
x &= NEQ(data[u], 0);
}
x &= EQ(data[len - 49], 0x00);
memmove(data, data + len - 48, 48);
return x;
}
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