Update NSPR to 4.12 and NSS to 3.23 on iOS

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>
 #include <stdlib.h>
 #include <sys/time.h>
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include "secrng.h"
 #include "secerr.h"
 #include "prerror.h"
 #include "prthread.h"
 #include "prprf.h"
+#include "prenv.h"
 
 size_t RNG_FileUpdate(const char *fileName, size_t limit);
 
 /*
  * When copying data to the buffer we want the least signicant bytes
  * from the input since those bits are changing the fastest. The address
  * of least significant byte depends upon whether we are running on
  * a big-endian or little-endian machine.
  *
  * Does this mean the least signicant bytes are the most significant
@@ skipping 851 matching lines @@
     /* Give in system information */
     if (gethostname(buf, sizeof(buf)) == 0) {
         RNG_RandomUpdate(buf, strlen(buf));
     }
     GiveSystemInfo();
 
     /* grab some data from system's PRNG before any other files. */
     bytes = RNG_FileUpdate("/dev/urandom", SYSTEM_RNG_SEED_COUNT);
 
     /* If the user points us to a random file, pass it through the rng */
-    randfile = getenv("NSRANDFILE");
+    randfile = PR_GetEnvSecure("NSRANDFILE");
     if ( ( randfile != NULL ) && ( randfile[0] != '\0') ) {
-        char *randCountString = getenv("NSRANDCOUNT");
+        char *randCountString = PR_GetEnvSecure("NSRANDCOUNT");
         int randCount = randCountString ? atoi(randCountString) : 0;
         if (randCount != 0) {
             RNG_FileUpdate(randfile, randCount);
         } else {
             RNG_FileForRNG(randfile);
         }
     }
 
     /* pass other files through */
     for (cp = files; *cp; cp++)
@@ skipping 175 matching lines @@
 
 #define entry_dir entry.dir
 #else
     struct dirent entry, firstEntry;
 #define entry_dir entry
 #endif
 
     int i, error = -1;
 
     if (fd == NULL) {
-        dir = getenv("HOME");
+        dir = PR_GetEnvSecure("HOME");
         if (dir) {
             fd = opendir(dir);
         }
     }
     if (fd == NULL) {
         return 1;
     }
 
     for (i=0; i <= fileToRead; i++) {
         struct dirent *result = NULL;
@@ skipping 83 matching lines @@
     }
     fclose(file);
     if (fileBytes != maxLen) {
         fprintf(stderr, "[ERROR:%s(%d)] NSS failed to read from /dev/urandom. "
                 "Abort process.\n", __FILE__, __LINE__);
         fflush(stderr);
         abort();
     }
     return fileBytes;
 }