1 // Copyright 2020 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "util/base64.h"
6 
7 #include <stddef.h>
8 
9 #include "third_party/modp_b64/modp_b64.h"
10 #include "util/osp_logging.h"
11 #include "util/std_util.h"
12 
13 namespace openscreen {
14 namespace base64 {
15 
Encode(absl::Span<const uint8_t> input)16 std::string Encode(absl::Span<const uint8_t> input) {
17   return Encode(absl::string_view(reinterpret_cast<const char*>(input.data()),
18                                   input.size()));
19 }
20 
Encode(absl::string_view input)21 std::string Encode(absl::string_view input) {
22   std::string out;
23   out.resize(modp_b64_encode_len(input.size()));
24 
25   const size_t output_size =
26       modp_b64_encode(data(out), input.data(), input.size());
27   if (output_size == MODP_B64_ERROR) {
28     return {};
29   }
30 
31   // The encode_len is generally larger than needed.
32   out.resize(output_size);
33   return out;
34 }
35 
Decode(absl::string_view input,std::string * output)36 bool Decode(absl::string_view input, std::string* output) {
37   std::string out;
38   out.resize(modp_b64_decode_len(input.size()));
39 
40   // We don't null terminate the result since it is binary data.
41   const size_t output_size =
42       modp_b64_decode(data(out), input.data(), input.size());
43   if (output_size == MODP_B64_ERROR) {
44     return false;
45   }
46 
47   // The output size from decode_len is generally larger than needed.
48   out.resize(output_size);
49   output->swap(out);
50   return true;
51 }
52 
53 }  // namespace base64
54 }  // namespace openscreen
55