olm/include/axolotl/message.hh
2015-02-25 11:20:12 +00:00

63 lines
1.4 KiB
C++

#include <cstddef>
#include <cstdint>
namespace axolotl {
/**
* The length of the buffer needed to hold a message.
*/
std::size_t encode_message_length(
std::uint32_t counter,
std::size_t ratchet_key_length,
std::size_t ciphertext_length,
std::size_t mac_length
);
struct MessageWriter {
std::size_t body_length;
std::uint8_t * ratchet_key;
std::uint8_t * ciphertext;
std::uint8_t * mac;
};
struct MessageReader {
std::size_t body_length;
std::uint8_t version;
std::uint32_t counter;
std::size_t ratchet_key_length;
std::size_t ciphertext_length;
std::size_t mac_length;
std::uint8_t const * ratchet_key;
std::uint8_t const * ciphertext;
std::uint8_t const * mac;
};
/**
* Writes the message headers into the output buffer.
* Returns a writer struct populated with pointers into the output buffer.
*/
MessageWriter encode_message(
std::uint8_t version,
std::uint32_t counter,
std::size_t ratchet_key_length,
std::size_t ciphertext_length,
std::uint8_t * output
);
/**
* Reads the message headers from the input buffer.
* Returns a reader struct populated with pointers into the input buffer.
* On failure the returned body_length will be 0.
*/
MessageReader decode_message(
std::uint8_t const * input, std::size_t input_length,
std::size_t mac_length
);
} // namespace axolotl