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

[tinc] / src / net_setup.c

diff --git a/src/net_setup.c b/src/net_setup.c
index 6c50f9d..2371f7e 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>
 
@@ -650,14 +650,28 @@ static bool setup_myself(void) {
                }
                free(cipher);
        } else
-               myself->incipher = EVP_bf_cbc();
+               myself->incipher = EVP_aes_256_cbc();
 
        if(myself->incipher)
                myself->inkeylength = EVP_CIPHER_key_length(myself->incipher) + EVP_CIPHER_iv_length(myself->incipher);
        else
                myself->inkeylength = 1;
 
-       myself->connection->outcipher = EVP_bf_ofb();
+       /* 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 = myself->incipher ? EVP_CIPHER_key_length(myself->incipher) : 0;
+       if(keylen <= 16)
+               myself->connection->outcipher = EVP_aes_128_cfb();
+       else if(keylen <= 24)
+               myself->connection->outcipher = EVP_aes_192_cfb();
+       else
+               myself->connection->outcipher = EVP_aes_256_cfb();
 
        if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
                keylifetime = 3600;
@@ -681,9 +695,9 @@ static bool setup_myself(void) {
 
                free(digest);
        } else
-               myself->indigest = EVP_sha1();
+               myself->indigest = EVP_sha256();
 
-       myself->connection->outdigest = EVP_sha1();
+       myself->connection->outdigest = EVP_sha256();
 
        if(get_config_int(lookup_config(config_tree, "MACLength"), &myself->inmaclength)) {
                if(myself->indigest) {