[Minor] Lua_cryptobox: Allow to define output hash length

diff --git a/src/lua/lua_cryptobox.c b/src/lua/lua_cryptobox.c
index cb531a5e1b5213da9b82bb188cd4bb20851cbdf4..300c33793b4e199ee5bb5acdd76bc7d980f2f8a4 100644 (file)
--- a/src/lua/lua_cryptobox.c
+++ b/src/lua/lua_cryptobox.c
@@ -1321,14 +1321,25 @@ lua_cryptobox_hash_hex (lua_State *L)
        LUA_TRACE_POINT;
        struct rspamd_lua_cryptobox_hash *h = lua_check_cryptobox_hash (L, 1);
        guchar out[rspamd_cryptobox_HASHBYTES],
-               out_hex[rspamd_cryptobox_HASHBYTES * 2 + 1];
+               out_hex[rspamd_cryptobox_HASHBYTES * 2 + 1], *r;
        guint dlen;
 
        if (h && !h->is_finished) {
                memset (out_hex, 0, sizeof (out_hex));
 
                lua_cryptobox_hash_finish (h, out, &dlen);
-               rspamd_encode_hex_buf (out, dlen, out_hex, sizeof (out_hex));
+               r = out;
+
+               if (lua_isnumber (L, 2)) {
+                       guint lim = lua_tonumber (L, 2);
+
+                       if (lim < dlen) {
+                               r += dlen - lim;
+                               dlen = lim;
+                       }
+               }
+
+               rspamd_encode_hex_buf (r, dlen, out_hex, sizeof (out_hex));
                lua_pushstring (L, out_hex);
 
        }
@@ -1350,13 +1361,24 @@ lua_cryptobox_hash_base32 (lua_State *L)
        LUA_TRACE_POINT;
        struct rspamd_lua_cryptobox_hash *h = lua_check_cryptobox_hash (L, 1);
        guchar out[rspamd_cryptobox_HASHBYTES],
-               out_b32[rspamd_cryptobox_HASHBYTES * 2];
+               out_b32[rspamd_cryptobox_HASHBYTES * 2], *r;
        guint dlen;
 
        if (h && !h->is_finished) {
                memset (out_b32, 0, sizeof (out_b32));
                lua_cryptobox_hash_finish (h, out, &dlen);
-               rspamd_encode_base32_buf (out, dlen, out_b32, sizeof (out_b32));
+               r = out;
+
+               if (lua_isnumber (L, 2)) {
+                       guint lim = lua_tonumber (L, 2);
+
+                       if (lim < dlen) {
+                               r += dlen - lim;
+                               dlen = lim;
+                       }
+               }
+
+               rspamd_encode_base32_buf (r, dlen, out_b32, sizeof (out_b32));
                lua_pushstring (L, out_b32);
                h->is_finished = TRUE;
        }
@@ -1377,13 +1399,24 @@ lua_cryptobox_hash_base64 (lua_State *L)
 {
        LUA_TRACE_POINT;
        struct rspamd_lua_cryptobox_hash *h = lua_check_cryptobox_hash (L, 1);
-       guchar out[rspamd_cryptobox_HASHBYTES], *b64;
+       guchar out[rspamd_cryptobox_HASHBYTES], *b64, *r;
        gsize len;
        guint dlen;
 
        if (h && !h->is_finished) {
                lua_cryptobox_hash_finish (h, out, &dlen);
-               b64 = rspamd_encode_base64 (out, dlen, 0, &len);
+               r = out;
+
+               if (lua_isnumber (L, 2)) {
+                       guint lim = lua_tonumber (L, 2);
+
+                       if (lim < dlen) {
+                               r += dlen - lim;
+                               dlen = lim;
+                       }
+               }
+
+               b64 = rspamd_encode_base64 (r, dlen, 0, &len);
                lua_pushlstring (L, b64, len);
                g_free (b64);
                h->is_finished = TRUE;
@@ -1405,12 +1438,23 @@ lua_cryptobox_hash_bin (lua_State *L)
 {
        LUA_TRACE_POINT;
        struct rspamd_lua_cryptobox_hash *h = lua_check_cryptobox_hash (L, 1);
-       guchar out[rspamd_cryptobox_HASHBYTES];
+       guchar out[rspamd_cryptobox_HASHBYTES], *r;
        guint dlen;
 
        if (h && !h->is_finished) {
                lua_cryptobox_hash_finish (h, out, &dlen);
-               lua_pushlstring (L, out, dlen);
+               r = out;
+
+               if (lua_isnumber (L, 2)) {
+                       guint lim = lua_tonumber (L, 2);
+
+                       if (lim < dlen) {
+                               r += dlen - lim;
+                               dlen = lim;
+                       }
+               }
+
+               lua_pushlstring (L, r, dlen);
                h->is_finished = TRUE;
        }
        else {