From dc25573ed79a0d55c5a24b20474aa8504a758a2c Mon Sep 17 00:00:00 2001 From: David Monniaux Date: Sat, 2 Feb 2019 12:03:44 +0100 Subject: BearSSL --- test/monniaux/BearSSL/src/ec/ec_keygen.c | 86 ++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 test/monniaux/BearSSL/src/ec/ec_keygen.c (limited to 'test/monniaux/BearSSL/src/ec/ec_keygen.c') diff --git a/test/monniaux/BearSSL/src/ec/ec_keygen.c b/test/monniaux/BearSSL/src/ec/ec_keygen.c new file mode 100644 index 00000000..02a30962 --- /dev/null +++ b/test/monniaux/BearSSL/src/ec/ec_keygen.c @@ -0,0 +1,86 @@ +/* + * Copyright (c) 2018 Thomas Pornin + * + * 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_ec.h */ +size_t +br_ec_keygen(const br_prng_class **rng_ctx, + const br_ec_impl *impl, br_ec_private_key *sk, + void *kbuf, int curve) +{ + const unsigned char *order; + unsigned char *buf; + size_t len; + unsigned mask; + + if (curve < 0 || curve >= 32 + || ((impl->supported_curves >> curve) & 1) == 0) + { + return 0; + } + order = impl->order(curve, &len); + while (len > 0 && *order == 0) { + order ++; + len --; + } + if (kbuf == NULL || len == 0) { + return len; + } + mask = order[0]; + mask |= (mask >> 1); + mask |= (mask >> 2); + mask |= (mask >> 4); + + /* + * We generate sequences of random bits of the right size, until + * the value is strictly lower than the curve order (we also + * check for all-zero values, which are invalid). + */ + buf = kbuf; + for (;;) { + size_t u; + unsigned cc, zz; + + (*rng_ctx)->generate(rng_ctx, buf, len); + buf[0] &= mask; + cc = 0; + u = len; + zz = 0; + while (u -- > 0) { + cc = ((unsigned)(buf[u] - order[u] - cc) >> 8) & 1; + zz |= buf[u]; + } + if (cc != 0 && zz != 0) { + break; + } + } + + if (sk != NULL) { + sk->curve = curve; + sk->x = buf; + sk->xlen = len; + } + return len; +} -- cgit