Don't dereference myself->incipher if it's NULL.

[oweals/tinc.git] / src / net_setup.c

diff --git a/src/net_setup.c b/src/net_setup.c
index 5b985c342c727da95b5d55b9748c19aff804b1b3..2371f7ee099c5390800ec484387867d874bf0c75 100644 (file)
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -1,7 +1,7 @@
 /*
     net_setup.c -- Setup.
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2016 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2017 Guus Sliepen <guus@tinc-vpn.org>
                   2006      Scott Lamb <slamb@slamb.org>
                   2010      Brandon Black <blblack@gmail.com>
 
@@ -657,18 +657,21 @@ static bool setup_myself(void) {
        else
                myself->inkeylength = 1;
 
-       /* We need to use OFB mode for the meta protocol. Use AES for this,
+       /* We need to use a stream mode for the meta protocol. Use AES for this,
           but try to match the key size with the one from the cipher selected
           by Cipher.
+
+          If Cipher is set to none, still use a low level of encryption for the
+          meta protocol.
        */
 
-       int keylen = EVP_CIPHER_key_length(myself->incipher);
+       int keylen = myself->incipher ? EVP_CIPHER_key_length(myself->incipher) : 0;
        if(keylen <= 16)
-               myself->connection->outcipher = EVP_aes_128_ofb();
+               myself->connection->outcipher = EVP_aes_128_cfb();
        else if(keylen <= 24)
-               myself->connection->outcipher = EVP_aes_192_ofb();
+               myself->connection->outcipher = EVP_aes_192_cfb();
        else
-               myself->connection->outcipher = EVP_aes_256_ofb();
+               myself->connection->outcipher = EVP_aes_256_cfb();
 
        if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
                keylifetime = 3600;