27 lines
788 B
C
27 lines
788 B
C
/* ESP8266 "Hardware RNG" (validity still being confirmed) support for ESP8266
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*
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* Based on research done by @foogod.
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*
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* Please don't rely on this too much as an entropy source, quite yet...
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*
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* Part of esp-open-rtos
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* Copyright (C) 2015 Angus Gratton
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* BSD Licensed as described in the file LICENSE
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*/
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#include <mbedtls/entropy_poll.h>
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#include <esp/wdev_regs.h>
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#include <string.h>
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int mbedtls_hardware_poll( void *data,
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unsigned char *output, size_t len, size_t *olen )
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{
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(void)(data);
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for(int i = 0; i < len; i+=4) {
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uint32_t random = WDEV.HWRNG;
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/* using memcpy here in case output is unaligned */
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memcpy(output + i, &random, (i+4 <= len) ? 4 : (len % 4));
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}
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if(olen)
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*olen = len;
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return 0;
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}
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