RNG_SystemRNG should fail rather than falling back on rng_systemFromNoise

nss/lib/freebl/unix_rand.c

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include <stdio.h>
 #include <string.h>
 #include <signal.h>
 #include <unistd.h>
 #include <limits.h>
 #include <errno.h>
@@ skipping 898 matching lines @@
  * BSD/OS we do not call safe_popen when we succeeded in getting data
  * from /dev/urandom.
  *
  * Bug 174993: On platforms providing /dev/urandom, don't fork netstat
  * either, if data has been gathered successfully.
  */
 
 #if defined(BSDI) || defined(FREEBSD) || defined(NETBSD) \
     || defined(OPENBSD) || defined(DARWIN) || defined(LINUX) \
     || defined(HPUX)
-    if (bytes)
+    if (bytes == SYSTEM_RNG_SEED_COUNT)
         return;
 
     /*
      * Modified to abort the process if it failed to read from /dev/urandom.
      *
      * See crbug.com/244661 for details.
      */
-    fprintf(stderr, "[ERROR:%s(%d)] NSS failed to read from /dev/urandom. "
-            "Abort process.\n", __FILE__, __LINE__);
+    fprintf(stderr, "[ERROR:%s(%d)] NSS read %zu bytes (expected %d bytes) "
+            "from /dev/urandom. Abort process.\n", __FILE__, __LINE__,
+            bytes, SYSTEM_RNG_SEED_COUNT);
     fflush(stderr);
     abort();
 #endif
 
 #ifdef SOLARIS
 
 /*
  * On Solaris, NSS may be initialized automatically from libldap in
  * applications that are unaware of the use of NSS. safe_popen forks, and
  * sometimes creates issues with some applications' pthread_atfork handlers.
@@ skipping 187 matching lines @@
 {
    static int fileToRead = 1;
 
    if (ReadOneFile(fileToRead)) {
         fileToRead = 1;
    } else {
         fileToRead++;
    }
 }
 
+/*
+ * Modified to abort the process if it failed to read from /dev/urandom.
+ *
+ * See crbug.com/244661 for details.
+ */
 size_t RNG_SystemRNG(void *dest, size_t maxLen)
 {
     FILE *file;
     size_t bytes;
     size_t fileBytes = 0;
     unsigned char *buffer = dest;
 
     file = fopen("/dev/urandom", "r");
     if (file == NULL) {
-        /*
-         * Modified to abort the process if it failed to read from /dev/urandom.
-         *
-         * See crbug.com/244661 for details.
-         */
         fprintf(stderr, "[ERROR:%s(%d)] NSS failed to read from /dev/urandom. "
                 "Abort process.\n", __FILE__, __LINE__);
         fflush(stderr);
         abort();
     }
     while (maxLen > fileBytes) {
         bytes = maxLen - fileBytes;
         bytes = fread(buffer, 1, bytes, file);
         if (bytes == 0) 
             break;
         fileBytes += bytes;
         buffer += bytes;
     }
     fclose(file);
     if (fileBytes != maxLen) {
-        PORT_SetError(SEC_ERROR_NEED_RANDOM);  /* system RNG failed */
-        fileBytes = 0;
+        fprintf(stderr, "[ERROR:%s(%d)] NSS failed to read from /dev/urandom. "
+                "Abort process.\n", __FILE__, __LINE__);
+        fflush(stderr);
+        abort();
     }
     return fileBytes;
 }