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https://github.com/trezor/trezor-firmware.git
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46 lines
1.2 KiB
C
46 lines
1.2 KiB
C
/*
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* This file is part of the TREZOR project.
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*
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* Copyright (C) 2014 Pavol Rusnak <stick@satoshilabs.com>
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*
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* This library is free software: you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this library. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <libopencm3/stm32/f2/rng.h>
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#include "rng.h"
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uint32_t random32(void)
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{
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static uint32_t last = 0, new = 0;
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while (new == last) {
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if (((RNG_SR & (RNG_SR_SEIS | RNG_SR_CEIS)) == 0) && ((RNG_SR & RNG_SR_DRDY) > 0)) {
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new = RNG_DR;
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}
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}
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last = new;
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return new;
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}
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void random_buffer(uint8_t *buf, uint32_t len)
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{
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uint32_t i, r = 0;
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for (i = 0; i < len; i++) {
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if (i % 4 == 0) {
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r = random32();
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}
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buf[i] = (r >> ((i % 4) * 8)) & 0xFF;
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}
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}
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