1 files changed, 97 insertions, 0 deletions
diff --git a/include/dnsjit/lib/base64url.lua b/include/dnsjit/lib/base64url.lua
new file mode 100644
index 0000000..8a408f5
--- /dev/null
+++ b/include/dnsjit/lib/base64url.lua
@@ -0,0 +1,97 @@
+-- Copyright (c) 2020, CZ.NIC, z.s.p.o.
+-- All rights reserved.
+--
+-- This file is part of dnsjit.
+--
+-- dnsjit is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- dnsjit is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with dnsjit.  If not, see <http://www.gnu.org/licenses/>.
+
+-- dnsjit.lib.base64url
+-- Utility library to convert data to base64url format
+--   local base64url = require("dnsjit.lib.base64url")
+-- .SS Encoding and decoding lua strings
+--   local encoded = base64url.encode("abcd")
+--   local decoded = base64url.decode(encoded)
+-- .SS Encoding C byte arrays
+--   local pl  -- pl is core.object.payload
+--   local encoded = base64url.encode(pl.payload, pl.len)
+--
+-- Encode and decode data to/from base64url format.
+module(...,package.seeall)
+
+require("dnsjit.lib.base64url_h")
+local ffi = require("ffi")
+local C = ffi.C
+local log = require("dnsjit.core.log")
+local module_log = log.new("lib.base64url")
+
+Base64Url = {}
+
+-- Encode lua string or C byte array to base64url representation.
+-- The input string may contain non-printable characters.
+--
+-- .B data_len
+-- is length of the input data (optional for lua strings, required for
+-- C byte arrays).
+function Base64Url.encode(data, data_len)
+    data_len = tonumber(data_len)  -- in case of cdata length
+    if type(data) == "cdata" then
+        if type(data_len) ~= "number" then
+            module_log:fatal("encode: data_len must be specified for cdata")
+            return
+        end
+    elseif type(data) ~= "string" then
+        module_log:fatal("encode: input must be string")
+        return
+    end
+
+    if data_len ~= nil and data_len < 0 then
+        module_log:fatal("encode: data_len must be greater than 0")
+        return
+    end
+
+    local in_len = data_len or string.len(data)
+    local buf_len = math.ceil(4 * in_len / 3) + 2
+    local buf = ffi.new("uint8_t[?]", buf_len)
+    local out_len = ffi.C.base64url_encode(data, in_len, buf, buf_len)
+    if out_len < 0 then
+        module_log:critical("encode: error ("..log.errstr(-out_len)..")")
+        return
+    end
+    return ffi.string(buf, out_len)
+end
+
+-- Decode a base64url encoded lua string.
+-- The output string may contain non-printable characters.
+function Base64Url.decode(data)
+    if type(data) ~= "string" then
+        module_log:fatal("decode: input must be string")
+        return
+    end
+
+    local in_len = string.len(data)
+    local buf_len = math.ceil(3 * in_len / 4) + 1
+    local buf = ffi.new("uint8_t[?]", buf_len)
+    local out_len = ffi.C.base64url_decode(data, in_len, buf, buf_len)
+    if out_len == -34 then  -- ERANGE
+        module_log:critical("decode: error "..log.errstr(-out_len).." - invalid character(s) in input string?")
+        return
+    elseif out_len < 0 then
+        module_log:critical("decode: error "..log.errstr(-out_len))
+        return
+    end
+    return ffi.string(buf, out_len)
+end
+
+-- dnsjit.core.object.payload (3)
+return Base64Url