| /* |
| * Copyright (c) 2016, The OpenThread Authors. |
| * 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. Neither the name of the copyright holder nor the |
| * names of its contributors may be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS 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 COPYRIGHT HOLDER OR 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. |
| */ |
| |
| /** |
| * @file |
| * This file implements a pseudo-random number generator. |
| * |
| */ |
| |
| #include <assert.h> |
| #include <stdio.h> |
| |
| #include "platform-posix.h" |
| |
| #include <openthread/types.h> |
| #include <openthread/platform/random.h> |
| |
| #include "utils/code_utils.h" |
| |
| static uint32_t sState = 1; |
| |
| void platformRandomInit(void) |
| { |
| #if __SANITIZE_ADDRESS__ == 0 |
| |
| otError error; |
| |
| error = otPlatRandomGetTrue((uint8_t *)&sState, sizeof(sState)); |
| assert(error == OT_ERROR_NONE); |
| |
| #else // __SANITIZE_ADDRESS__ |
| |
| // Multiplying NODE_ID assures that no two nodes gets the same seed within an hour. |
| sState = (uint32_t)time(NULL) + (3600 * NODE_ID); |
| |
| #endif // __SANITIZE_ADDRESS__ |
| } |
| |
| uint32_t otPlatRandomGet(void) |
| { |
| uint32_t mlcg, p, q; |
| uint64_t tmpstate; |
| |
| tmpstate = (uint64_t)33614 * (uint64_t)sState; |
| q = tmpstate & 0xffffffff; |
| q = q >> 1; |
| p = tmpstate >> 32; |
| mlcg = p + q; |
| |
| if (mlcg & 0x80000000) |
| { |
| mlcg &= 0x7fffffff; |
| mlcg++; |
| } |
| |
| sState = mlcg; |
| |
| return mlcg; |
| } |
| |
| otError otPlatRandomGetTrue(uint8_t *aOutput, uint16_t aOutputLength) |
| { |
| otError error = OT_ERROR_NONE; |
| |
| #if __SANITIZE_ADDRESS__ == 0 |
| |
| FILE *file = NULL; |
| size_t readLength; |
| |
| otEXPECT_ACTION(aOutput && aOutputLength, error = OT_ERROR_INVALID_ARGS); |
| |
| file = fopen("/dev/urandom", "rb"); |
| otEXPECT_ACTION(file != NULL, error = OT_ERROR_FAILED); |
| |
| readLength = fread(aOutput, 1, aOutputLength, file); |
| otEXPECT_ACTION(readLength == aOutputLength, error = OT_ERROR_FAILED); |
| |
| exit: |
| |
| if (file != NULL) |
| { |
| fclose(file); |
| } |
| |
| #else // __SANITIZE_ADDRESS__ |
| |
| /* |
| * THE IMPLEMENTATION BELOW IS NOT COMPLIANT WITH THE THREAD SPECIFICATION. |
| * |
| * Address Sanitizer triggers test failures when reading random |
| * values from /dev/urandom. The pseudo-random number generator |
| * implementation below is only used to enable continuous |
| * integration checks with Address Sanitizer enabled. |
| */ |
| otEXPECT_ACTION(aOutput && aOutputLength, error = OT_ERROR_INVALID_ARGS); |
| |
| for (uint16_t length = 0; length < aOutputLength; length++) |
| { |
| aOutput[length] = (uint8_t)otPlatRandomGet(); |
| } |
| |
| exit: |
| |
| #endif // __SANITIZE_ADDRESS__ |
| |
| return error; |
| } |