Neels Hofmeyr | 7209277 | 2015-10-12 11:57:33 +0200 | [diff] [blame] | 1 | /* OpenBSC kitchen sink */ |
| 2 | |
| 3 | /* (C) 2015 by sysmocom s.m.f.c GmbH <info@sysmocom.de> |
| 4 | * All Rights Reserved |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU Affero General Public License as published by |
| 8 | * the Free Software Foundation; either version 3 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU Affero General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Affero General Public License |
| 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | */ |
| 20 | |
| 21 | #include <openbsc/utils.h> |
| 22 | #include <osmocom/core/utils.h> |
| 23 | #include <osmocom/core/bit64gen.h> |
| 24 | |
| 25 | /* Wishful thinking to generate a constant time compare */ |
| 26 | int constant_time_cmp(const uint8_t *exp, const uint8_t *rel, const int count) |
| 27 | { |
| 28 | int x = 0, i; |
| 29 | |
| 30 | for (i = 0; i < count; ++i) |
| 31 | x |= exp[i] ^ rel[i]; |
| 32 | |
| 33 | /* if x is zero, all data was identical */ |
| 34 | return x? 1 : 0; |
| 35 | } |
| 36 | |
| 37 | |
| 38 | uint64_t decode_big_endian(const uint8_t *data, size_t data_len) |
| 39 | { |
| 40 | uint64_t value = 0; |
| 41 | |
| 42 | while (data_len > 0) { |
| 43 | value = (value << 8) + *data; |
| 44 | data += 1; |
| 45 | data_len -= 1; |
| 46 | } |
| 47 | |
| 48 | return value; |
| 49 | } |
| 50 | |
| 51 | uint8_t *encode_big_endian(uint64_t value, size_t data_len) |
| 52 | { |
| 53 | static uint8_t buf[sizeof(uint64_t)]; |
| 54 | OSMO_ASSERT(data_len <= ARRAY_SIZE(buf)); |
| 55 | osmo_store64be_ext(value, buf, data_len); |
| 56 | return buf; |
| 57 | } |
| 58 | |