/*
Priority order of PRNG algorithms and then default GetEntropy if none.
Does an initial entropy source and reseeding
*/
int32 psInitPrng(psRandom_t *ctx, void *userPtr)
{
#if defined(USE_FORTUNA) || defined(USE_YARROW)
unsigned char entropyBytes[RANDOM_ENTROPY_BYTES];
int32 rc;
#endif
ctx->bytecount = 0;
#if defined(USE_FORTUNA) || defined(USE_YARROW)
if ((rc = psGetEntropy(entropyBytes, RANDOM_ENTROPY_BYTES, userPtr)) < 0) {
return rc;
}
#endif
#ifdef USE_YARROW
if ((rc = psYarrowStart(&ctx->yarrow)) < 0) {
return rc;
}
if ((rc = psYarrowAddEntropy(entropyBytes, RANDOM_ENTROPY_BYTES,
&ctx->yarrow)) < 0) {
return rc;
}
if ((rc = psYarrowReseed(&ctx->yarrow)) < 0) {
return rc;
}
#endif
return PS_SUCCESS;
}
/**
Import a PRNG state
@param in The PRNG state
@param inlen Size of the state
@param prng The PRNG to import
@return CRYPT_OK if successful
*/
int32 psYarrowImport(unsigned char *in, uint32 inlen, psYarrow_t *ctx)
{
int32 err;
if (inlen != 64) {
return PS_ARG_FAIL;
}
if ((err = psYarrowStart(ctx)) != PS_SUCCESS) {
return err;
}
if ((err = psYarrowAddEntropy(in, 64, ctx)) != PS_SUCCESS) {
return err;
}
if ((err = psYarrowReseed(ctx)) != PS_SUCCESS) {
return err;
}
return err;
}
/*
Performs the read
*/
static int32 readRandomData(psRandom_t *ctx, unsigned char *bytes, uint32 size)
{
#if defined(USE_FORTUNA) || defined(USE_YARROW)
unsigned char entropyBytes[RANDOM_ENTROPY_BYTES];
int32 rc;
#endif
/*
Return random data. The defines above control how often to add
entropy and reseed the key.
*/
ctx->callcount++;
ctx->bytecount += size;
#ifdef USE_YARROW
if (ctx->bytecount >= RANDOM_BYTES_BEFORE_ENTROPY) {
if ((rc = psGetEntropy(entropyBytes, RANDOM_ENTROPY_BYTES)) < 0) {
return rc;
}
if ((rc = psYarrowAddEntropy(entropyBytes, RANDOM_ENTROPY_BYTES,
&ctx->yarrow)) < 0) {
return rc;
}
ctx->bytecount = 0;
}
if (ctx->callcount >= RANDOM_CALLS_BEFORE_RESEED) {
if ((rc = psYarrowReseed(&ctx->yarrow)) < 0) {
return rc;
}
ctx->callcount = 0;
}
return psYarrowRead(bytes, size, &ctx->yarrow);
#endif
/*
If no PRNG algorithms defined, default to the low level GetEntropy function
for all the randomness
*/
return psGetEntropy(bytes, size);
}
