From 48e7b098f86207f8596651b5ba8242a3b834a868 Mon Sep 17 00:00:00 2001
From: debevv <valerio@sonicpengu.in>
Date: Tue, 6 Jun 2017 09:28:58 +0200
Subject: [PATCH] wrapper: Fix possible crash in ssh_handle_key_exchange()

If ssh_handle_key_exchange() fails, when ssh_free() is called
cipher->ctx is NULL.

Signed-off-by: debevv <valerio@sonicpengu.in>
---
 src/wrapper.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/wrapper.c b/src/wrapper.c
index af166dae..877b807b 100644
--- a/src/wrapper.c
+++ b/src/wrapper.c
@@ -120,12 +120,14 @@ void ssh_cipher_clear(struct ssh_cipher_struct *cipher){
     SAFE_FREE(cipher->key);
   }
 #endif
-  if (cipher->cleanup != NULL){
-    cipher->cleanup(cipher);
-  }
+  if (cipher->ctx != NULL) {
+    if (cipher->cleanup != NULL) {
+      cipher->cleanup(cipher);
+    }
 #ifdef HAVE_LIBCRYPTO
-  EVP_CIPHER_CTX_free(cipher->ctx);
+    EVP_CIPHER_CTX_free(cipher->ctx);
 #endif
+  }
 }
 
 static void cipher_free(struct ssh_cipher_struct *cipher) {