Check DKIM fields length before decoding.

diff --git a/src/libserver/dkim.c b/src/libserver/dkim.c
index ecc218434ec3a4f110252d2f83a754c7de561be8..3c6146a376f7d8ceaa8ff87fb51018a5041376e3 100644 (file)
--- a/src/libserver/dkim.c
+++ b/src/libserver/dkim.c
@@ -629,6 +629,7 @@ rspamd_create_dkim_context (const gchar *sig,
                case DKIM_STATE_VALUE:
                        if (*p == ';') {
                                if (param == DKIM_PARAM_UNKNOWN ||
+                                       p - c == 0 ||
                                        !parser_funcs[param](new, c, p - c, err)) {
                                        state = DKIM_STATE_ERROR;
                                }