static void sha384_finish_wrap( void *ctx, unsigned char *output )
{
mbedtls_sha512_finish( (mbedtls_sha512_context *) ctx, output );
}
int mbedtls_entropy_func(void *data, unsigned char *output, size_t len)
{
int ret, count = 0, i, done;
mbedtls_entropy_context *ctx = (mbedtls_entropy_context *)data;
unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
if (len > MBEDTLS_ENTROPY_BLOCK_SIZE) {
return (MBEDTLS_ERR_ENTROPY_SOURCE_FAILED);
}
#if defined(MBEDTLS_ENTROPY_NV_SEED)
/* Update the NV entropy seed before generating any entropy for outside
* use.
*/
if (ctx->initial_entropy_run == 0) {
ctx->initial_entropy_run = 1;
if ((ret = mbedtls_entropy_update_nv_seed(ctx)) != 0) {
return (ret);
}
}
#endif
#if defined(MBEDTLS_THREADING_C)
if ((ret = mbedtls_mutex_lock(&ctx->mutex)) != 0) {
return (ret);
}
#endif
/*
* Always gather extra entropy before a call
*/
do {
if (count++ > ENTROPY_MAX_LOOP) {
ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
goto exit;
}
if ((ret = entropy_gather_internal(ctx)) != 0) {
goto exit;
}
done = 1;
for (i = 0; i < ctx->source_count; i++)
if (ctx->source[i].size < ctx->source[i].threshold) {
done = 0;
}
} while (!done);
memset(buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE);
#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
mbedtls_sha512_finish(&ctx->accumulator, buf);
/*
* Reset accumulator and counters and recycle existing entropy
*/
memset(&ctx->accumulator, 0, sizeof(mbedtls_sha512_context));
mbedtls_sha512_starts(&ctx->accumulator, 0);
mbedtls_sha512_update(&ctx->accumulator, buf, MBEDTLS_ENTROPY_BLOCK_SIZE);
/*
* Perform second SHA-512 on entropy
*/
mbedtls_sha512(buf, MBEDTLS_ENTROPY_BLOCK_SIZE, buf, 0);
#else /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
mbedtls_sha256_finish(&ctx->accumulator, buf);
/*
* Reset accumulator and counters and recycle existing entropy
*/
memset(&ctx->accumulator, 0, sizeof(mbedtls_sha256_context));
mbedtls_sha256_starts(&ctx->accumulator, 0);
mbedtls_sha256_update(&ctx->accumulator, buf, MBEDTLS_ENTROPY_BLOCK_SIZE);
/*
* Perform second SHA-256 on entropy
*/
mbedtls_sha256(buf, MBEDTLS_ENTROPY_BLOCK_SIZE, buf, 0);
#endif /* MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
for (i = 0; i < ctx->source_count; i++) {
ctx->source[i].size = 0;
}
memcpy(output, buf, len);
ret = 0;
exit:
#if defined(MBEDTLS_THREADING_C)
if (mbedtls_mutex_unlock(&ctx->mutex) != 0) {
return (MBEDTLS_ERR_THREADING_MUTEX_ERROR);
}
#endif
return (ret);
}
