Use arc4random_buf() instead of RAND_bytes() or RAND_pseudo_bytes().

arc4random provides high quality pseudo-random numbers, hence there is no
need to differentiate between "strong" and "pseudo". Furthermore, the
arc4random_buf() function is guaranteed to succeed, which avoids the need
to check for and handle failure, simplifying the code.

It is worth noting that a number of the replaced RAND_bytes() and
RAND_pseudo_bytes() calls were missing return value checks and these
functions can fail for a number of reasons (at least in OpenSSL -
thankfully they were converted to wrappers around arc4random_buf() some
time ago in LibreSSL).

ok beck@ deraadt@ miod@

1 files changed, 3 insertions, 5 deletions

diff --git a/src/lib/libssl/d1_srvr.c b/src/lib/libssl/d1_srvr.c
index 68441fa63a..a85715753c 100644
--- a/src/lib/libssl/d1_srvr.c
+++ b/src/lib/libssl/d1_srvr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: d1_srvr.c,v 1.39 2014/09/27 11:03:43 jsing Exp $ */
+/* $OpenBSD: d1_srvr.c,v 1.40 2014/10/18 16:13:16 jsing Exp $ */
 /* 
  * DTLS implementation written by Nagendra Modadugu
  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.  
@@ -116,7 +116,6 @@
 #include <stdio.h>
 #include "ssl_locl.h"
 #include <openssl/buffer.h>
-#include <openssl/rand.h>
 #include <openssl/objects.h>
 #include <openssl/evp.h>
 #include <openssl/x509.h>
@@ -902,8 +901,7 @@ dtls1_send_server_hello(SSL *s)
 
         if (s->state == SSL3_ST_SW_SRVR_HELLO_A) {
                 buf = (unsigned char *)s->init_buf->data;
-                p = s->s3->server_random;
-                RAND_pseudo_bytes(p, SSL3_RANDOM_SIZE);
+                arc4random_buf(s->s3->server_random, SSL3_RANDOM_SIZE);
 
                 /* Do the message type and length last */
                 d = p= &(buf[DTLS1_HM_HEADER_LENGTH]);
@@ -1513,7 +1511,7 @@ dtls1_send_newsession_ticket(SSL *s)
                                 return -1;
                         }
                 } else {
-                        RAND_pseudo_bytes(iv, 16);
+                        arc4random_buf(iv, 16);
                         EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
                             tctx->tlsext_tick_aes_key, iv);
                         HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,