pw_tokenizer: C++ support for the Base64 format
Provide functions for encoding and decoding tokenized messages in the
standard prefixed Base64 format.
Change-Id: I8d09fddd29f5e3589228e5e1947cde11149c8233
diff --git a/pw_tokenizer/base64.cc b/pw_tokenizer/base64.cc
new file mode 100644
index 0000000..e05390e
--- /dev/null
+++ b/pw_tokenizer/base64.cc
@@ -0,0 +1,58 @@
+// Copyright 2020 The Pigweed Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+#include "pw_tokenizer/base64.h"
+
+#include "pw_base64/base64.h"
+#include "pw_span/span.h"
+
+namespace pw::tokenizer {
+
+extern "C" size_t pw_TokenizerPrefixedBase64Encode(
+ const void* binary_message,
+ size_t binary_size_bytes,
+ void* output_buffer,
+ size_t output_buffer_size_bytes) {
+ const size_t encoded_size = base64::EncodedSize(binary_size_bytes) + 1;
+
+ if (output_buffer_size_bytes < encoded_size) {
+ return 0;
+ }
+
+ char* output = static_cast<char*>(output_buffer);
+ output[0] = kBase64Prefix;
+
+ base64::Encode(
+ span(static_cast<const std::byte*>(binary_message), binary_size_bytes),
+ &output[1]);
+
+ return encoded_size;
+}
+
+extern "C" size_t pw_TokenizerPrefixedBase64Decode(const void* base64_message,
+ size_t base64_size_bytes,
+ void* output_buffer,
+ size_t output_buffer_size) {
+ const char* base64 = static_cast<const char*>(base64_message);
+
+ if (base64_size_bytes == 0 || base64[0] != kBase64Prefix) {
+ return 0;
+ }
+
+ return base64::Decode(
+ std::string_view(&base64[1], base64_size_bytes - 1),
+ span(static_cast<std::byte*>(output_buffer), output_buffer_size));
+}
+
+} // namespace pw::tokenizer