Bug 1334413 - Don't try to seed from /dev/urandom in fuzzing mode r=f…

…ranziskus

Differential Revision: https://nss-review.dev.mozaws.net/D179

--HG--
extra : amend_source : 62ca830db678672d7d744915ab3824975c389b04

lib/freebl/drbg.c

@@ -398,8 +398,10 @@ static PRStatus
 rng_init(void)
 {
     PRUint8 bytes[PRNG_SEEDLEN * 2]; /* entropy + nonce */
+#ifndef UNSAFE_FUZZER_MODE
     unsigned int numBytes;
     SECStatus rv = SECSuccess;
+#endif
 
     if (globalrng == NULL) {
         /* bytes needs to have enough space to hold
@@ -416,6 +418,7 @@ rng_init(void)
             return PR_FAILURE;
         }
 
+#ifndef UNSAFE_FUZZER_MODE
         /* Try to get some seed data for the RNG */
         numBytes = (unsigned int)RNG_SystemRNG(bytes, sizeof bytes);
         PORT_Assert(numBytes == 0 || numBytes == sizeof bytes);
@@ -435,10 +438,11 @@ rng_init(void)
             globalrng = NULL;
             return PR_FAILURE;
         }
-
         if (rv != SECSuccess) {
             return PR_FAILURE;
         }
+#endif
+
         /* the RNG is in a valid state */
         globalrng->isValid = PR_TRUE;