Add base64 decoding lua utility.

diff --git a/src/lua/lua_util.c b/src/lua/lua_util.c
index 7d7a31c592c1db0ec166638b511fe899de0ea9e3..ad4f80af46043cb6abb0900c4f7766059634928c 100644 (file)
--- a/src/lua/lua_util.c
+++ b/src/lua/lua_util.c
@@ -53,6 +53,13 @@ LUA_FUNCTION_DEF (util, config_from_ucl);
  * @return {rspamd_text} encoded data chunk
  */
 LUA_FUNCTION_DEF (util, encode_base64);
+/***
+ * @function util.decode_base64(input)
+ * Decodes data from base64 ignoring whitespace characters
+ * @param {text or string} input data to decode; if `rspamd{text}` is used then the string is modified **in-place**
+ * @return {rspamd_text} decoded data chunk
+ */
+LUA_FUNCTION_DEF (util, decode_base64);
 /***
  * @function util.tokenize_text(input[, exceptions])
  * Create tokens from a text using optional exceptions list
@@ -69,6 +76,7 @@ static const struct luaL_reg utillib_f[] = {
        LUA_INTERFACE_DEF (util, config_from_ucl),
        LUA_INTERFACE_DEF (util, process_message),
        LUA_INTERFACE_DEF (util, encode_base64),
+       LUA_INTERFACE_DEF (util, decode_base64),
        LUA_INTERFACE_DEF (util, tokenize_text),
        {NULL, NULL}
 };
@@ -260,6 +268,57 @@ lua_util_encode_base64 (lua_State *L)
        return 1;
 }
 
+static gint
+lua_util_decode_base64 (lua_State *L)
+{
+       struct rspamd_lua_text *t;
+       const gchar *s = NULL;
+       gsize inlen, outlen;
+       gboolean zero_copy = FALSE;
+       gint state = 0;
+       guint save = 0;
+
+       if (lua_type (L, 1) == LUA_TSTRING) {
+               s = luaL_checklstring (L, 1, &inlen);
+       }
+       else if (lua_type (L, 1) == LUA_TUSERDATA) {
+               t = lua_check_text (L, 1);
+
+               if (t != NULL) {
+                       s = t->start;
+                       inlen = t->len;
+                       zero_copy = TRUE;
+               }
+       }
+
+       if (s != NULL) {
+               if (zero_copy) {
+                       /* Decode in place */
+                       outlen = g_base64_decode_step (s, inlen, (gchar *)s, &state, &save);
+                       t = lua_newuserdata (L, sizeof (*t));
+                       rspamd_lua_setclass (L, "rspamd{text}", -1);
+                       t->start = s;
+                       t->len = outlen;
+                       t->own = FALSE;
+               }
+               else {
+                       t = lua_newuserdata (L, sizeof (*t));
+                       rspamd_lua_setclass (L, "rspamd{text}", -1);
+                       t->len = (inlen / 4) * 3 + 3;
+                       t->start = g_malloc (t->len);
+                       outlen = g_base64_decode_step (s, inlen, (gchar *)t->start,
+                                       &state, &save);
+                       t->len = outlen;
+                       t->own = TRUE;
+               }
+       }
+       else {
+               lua_pushnil (L);
+       }
+
+       return 1;
+}
+
 static gint
 lua_util_tokenize_text (lua_State *L)
 {