/**
PRNG self-test
@return CRYPT_OK if successful, CRYPT_NOP if self-testing has been disabled
*/
int rc4_test(void)
{
#if !defined(LTC_TEST) || defined(LTC_VALGRIND)
return CRYPT_NOP;
#else
static const struct {
unsigned char key[8], pt[8], ct[8];
} tests[] = {
{
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
{ 0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef },
{ 0x75, 0xb7, 0x87, 0x80, 0x99, 0xe0, 0xc5, 0x96 }
}
};
prng_state prng;
unsigned char dst[8];
int err, x;
for (x = 0; x < (int)(sizeof(tests)/sizeof(tests[0])); x++) {
if ((err = rc4_start(&prng)) != CRYPT_OK) {
return err;
}
if ((err = rc4_add_entropy(tests[x].key, 8, &prng)) != CRYPT_OK) {
return err;
}
if ((err = rc4_ready(&prng)) != CRYPT_OK) {
return err;
}
XMEMCPY(dst, tests[x].pt, 8);
if (rc4_read(dst, 8, &prng) != 8) {
return CRYPT_ERROR_READPRNG;
}
rc4_done(&prng);
if (XMEMCMP(dst, tests[x].ct, 8)) {
#if 0
int y;
printf("\n\nRC4 failed, I got:\n");
for (y = 0; y < 8; y++) printf("%02x ", dst[y]);
printf("\n");
#endif
return CRYPT_FAIL_TESTVECTOR;
}
}
return CRYPT_OK;
#endif
}
/**
Export the PRNG state
@param out [out] Destination
@param outlen [in/out] Max size and resulting size of the state
@param prng The PRNG to export
@return CRYPT_OK if successful
*/
int rc4_export(unsigned char *out, unsigned long *outlen, prng_state *prng)
{
LTC_ARGCHK(outlen != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(prng != NULL);
if (*outlen < 32) {
return CRYPT_BUFFER_OVERFLOW;
}
if (rc4_read(out, 32, prng) != 32) {
return CRYPT_ERROR_READPRNG;
}
*outlen = 32;
return CRYPT_OK;
}