Land https://codereview.chromium.org/889083003/ to update libsrtp to upstream 1.5.0

srtp/crypto/rng/ctr_prng.c

Index: srtp/crypto/rng/ctr_prng.c
===================================================================
--- srtp/crypto/rng/ctr_prng.c	(revision 294174)
+++ srtp/crypto/rng/ctr_prng.c	(working copy)
@@ -43,6 +43,10 @@
  */
 
 
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
 #include "prng.h"
 
 /* single, global prng structure */
@@ -66,7 +70,11 @@
     return status;
 
   /* initialize aes ctr context with random key */
+#ifdef OPENSSL
+  status = aes_icm_openssl_context_init(&ctr_prng.state, tmp_key, 30);
+#else
   status = aes_icm_context_init(&ctr_prng.state, tmp_key, 30);
+#endif
   if (status) 
     return status;
 
@@ -79,10 +87,8 @@
 
   /* 
    * if we need to re-initialize the prng, do so now 
-   *
-   * avoid 32-bit overflows by subtracting instead of adding
    */
-  if (ctr_prng.octet_count > MAX_PRNG_OUT_LEN - len) {
+  if ((aes_icm_bytes_encrypted(&ctr_prng.state) + len) > 0xffff) {
     status = ctr_prng_init(ctr_prng.rand);    
     if (status)
       return status;