/* * 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; } |