1 // Copyright 2020 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14
15 #include "pw_tokenizer/base64.h"
16
17 namespace pw::tokenizer {
18
pw_tokenizer_PrefixedBase64Encode(const void * binary_message,size_t binary_size_bytes,void * output_buffer,size_t output_buffer_size_bytes)19 extern "C" size_t pw_tokenizer_PrefixedBase64Encode(
20 const void* binary_message,
21 size_t binary_size_bytes,
22 void* output_buffer,
23 size_t output_buffer_size_bytes) {
24 char* output = static_cast<char*>(output_buffer);
25 const size_t encoded_size = Base64EncodedBufferSize(binary_size_bytes);
26
27 if (output_buffer_size_bytes < encoded_size) {
28 if (output_buffer_size_bytes > 0u) {
29 output[0] = '\0';
30 }
31
32 return 0;
33 }
34
35 output[0] = kBase64Prefix;
36 base64::Encode(std::span(static_cast<const std::byte*>(binary_message),
37 binary_size_bytes),
38 &output[1]);
39 output[encoded_size - 1] = '\0';
40 return encoded_size - sizeof('\0'); // exclude the null terminator
41 }
42
pw_tokenizer_PrefixedBase64Decode(const void * base64_message,size_t base64_size_bytes,void * output_buffer,size_t output_buffer_size)43 extern "C" size_t pw_tokenizer_PrefixedBase64Decode(const void* base64_message,
44 size_t base64_size_bytes,
45 void* output_buffer,
46 size_t output_buffer_size) {
47 const char* base64 = static_cast<const char*>(base64_message);
48
49 if (base64_size_bytes == 0 || base64[0] != kBase64Prefix) {
50 return 0;
51 }
52
53 return base64::Decode(
54 std::string_view(&base64[1], base64_size_bytes - 1),
55 std::span(static_cast<std::byte*>(output_buffer), output_buffer_size));
56 }
57
58 } // namespace pw::tokenizer
59