Fix use of snprintf() in IETF attributes to string conversion

diff --git a/src/libstrongswan/credentials/ietf_attributes/ietf_attributes.c b/src/libstrongswan/credentials/ietf_attributes/ietf_attributes.c
index ff3ddeb6f11f4e497512c1b9d6812804664cb894..de5b85bae26674336338e8f0a50baf815499dc0f 100644 (file)
--- a/src/libstrongswan/credentials/ietf_attributes/ietf_attributes.c
+++ b/src/libstrongswan/credentials/ietf_attributes/ietf_attributes.c
@@ -159,7 +159,7 @@ static char* get_string(private_ietf_attributes_t *this)
                enumerator = this->list->create_enumerator(this->list);
                while (enumerator->enumerate(enumerator, &attr))
                {
-                       int written = 0;
+                       int written;
 
                        if (first)
                        {
@@ -168,8 +168,12 @@ static char* get_string(private_ietf_attributes_t *this)
                        else
                        {
                                written = snprintf(pos, len, ", ");
+                               if (written < 0 || written >= len)
+                               {
+                                       break;
+                               }
                                pos += written;
-                               len -= written; 
+                               len -= written;
                        }
 
                        switch (attr->type)
@@ -194,8 +198,13 @@ static char* get_string(private_ietf_attributes_t *this)
                                        break;
                                }
                                default:
+                                       written = 0;
                                        break;
                        }
+                       if (written < 0 || written >= len)
+                       {
+                               break;
+                       }
                        pos += written;
                        len -= written;
                }