Update NSPR to 4.12 and NSS to 3.23 on iOS

nspr/pr/src/misc/prenv.c

Index: nspr/pr/src/misc/prenv.c
diff --git a/nspr/pr/src/misc/prenv.c b/nspr/pr/src/misc/prenv.c
index 4935f9dc78e65bbfda3cbe0edd861ef72e4dcd98..cc2e198b97823fffaaabdc26629a493c09fbc12d 100644
--- a/nspr/pr/src/misc/prenv.c
+++ b/nspr/pr/src/misc/prenv.c
@@ -4,10 +4,12 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include <string.h>
+#include <stdlib.h>
 #include "primpl.h"
 #include "prmem.h"
 
 #if defined(XP_UNIX)
+#include <unistd.h>
 #if defined(DARWIN)
 #if defined(HAVE_CRT_EXTERNS_H)
 #include <crt_externs.h>
@@ -17,6 +19,11 @@ PR_IMPORT_DATA(char **) environ;
 #endif /* DARWIN */
 #endif /* XP_UNIX */
 
+#if !defined(HAVE_SECURE_GETENV) && defined(HAVE___SECURE_GETENV)
+#define secure_getenv __secure_getenv
+#define HAVE_SECURE_GETENV 1
+#endif
+
 /* Lock used to lock the environment */
 #if defined(_PR_NO_PREEMPT)
 #define _PR_NEW_LOCK_ENV()
@@ -63,6 +70,34 @@ PR_IMPLEMENT(char*) PR_GetEnv(const char *var)
     return ev;
 }
 
+PR_IMPLEMENT(char*) PR_GetEnvSecure(const char *var)
+{
+#ifdef HAVE_SECURE_GETENV
+  char *ev;
+
+  if (!_pr_initialized) _PR_ImplicitInitialization();
+
+  _PR_LOCK_ENV();
+  ev = secure_getenv(var);
+  _PR_UNLOCK_ENV();
+
+  return ev;
+#else
+#ifdef XP_UNIX
+  /*
+  ** Fall back to checking uids and gids.  This won't detect any other
+  ** privilege-granting mechanisms the platform may have.  This also
+  ** can't detect the case where the process already called
+  ** setuid(geteuid()) and/or setgid(getegid()).
+  */
+  if (getuid() != geteuid() || getgid() != getegid()) {
+    return NULL;
+  }
+#endif /* XP_UNIX */
+  return PR_GetEnv(var);
+#endif /* HAVE_SECURE_GETENV */
+}
+
 PR_IMPLEMENT(PRStatus) PR_SetEnv(const char *string)
 {
     PRIntn result;