Commit 793b9b91 authored by Mark Haines's avatar Mark Haines
Browse files

Start writing the interfaces for session and the account objects

parent bcb05d1a
#ifndef AXOLOTL_ACCOUNT_HH_
#define AXOLOTL_ACCOUNT_HH_
#include "axolotl/list.hh"
#include <cstdint>
namespace axolotl {
struct LocalKey {
std::uint32_t id;
Curve25519KeyPair key;
};
struct SignedKey : LocalKey {
std::uint8_t signature[64];
};
static std::size_t const MAX_ONE_TIME_KEYS = 100;
struct Account {
LocalKey identity_key;
LocalKey last_resort_one_time_key;
List<LocalKey, MAX_ONE_TIME_KEYS> one_time_keys;
/** Number of random bytes needed to create a new account */
std::size_t new_account_random_length();
/** Create a new account. Returns NOT_ENOUGH_RANDOM if the number of random
* bytes is too small. */
ErrorCode new_account(
uint8_t const * random, std::size_t random_length
);
/** The number of bytes needed to persist this account. */
std::size_t pickle_length();
/** Persists an account as a sequence of bytes
* Returns the number of output bytes used. */
std::size_t pickle(
std::uint8_t * output, std::size_t output_length
);
/** Loads an account from a sequence of bytes.
* Returns 0 on success, or std::size_t(-1) on failure. */
std::size_t unpickle(
std::uint8_t * input, std::size_t input_length
);
};
} // namespace axolotl
#endif /* AXOLOTL_ACCOUNT_HH_ */
#ifndef ERROR_HH_
#define ERROR_HH_
namespace axolotl {
enum struct ErrorCode {
SUCCESS = 0, /*!< There wasn't an error */
NOT_ENOUGH_RANDOM = 1, /*!< Not enough entropy was supplied */
OUTPUT_BUFFER_TOO_SMALL = 2, /*!< Supplied output buffer is too small */
BAD_MESSAGE_VERSION = 3, /*!< The message version is unsupported */
BAD_MESSAGE_FORMAT = 4, /*!< The message couldn't be decoded */
BAD_MESSAGE_MAC = 5, /*!< The message couldn't be decrypted */
};
} // namespace axolotl
#endif /* ERROR_HH_ */
......@@ -15,6 +15,7 @@
#include "axolotl/crypto.hh"
#include "axolotl/list.hh"
#include "axolotl/error.hh"
namespace axolotl {
......@@ -53,16 +54,6 @@ struct SkippedMessageKey {
};
enum struct ErrorCode {
SUCCESS = 0, /*!< There wasn't an error */
NOT_ENOUGH_RANDOM = 1, /*!< Not enough entropy was supplied */
OUTPUT_BUFFER_TOO_SMALL = 2, /*!< Supplied output buffer is too small */
BAD_MESSAGE_VERSION = 3, /*!< The message version is unsupported */
BAD_MESSAGE_FORMAT = 4, /*!< The message couldn't be decoded */
BAD_MESSAGE_MAC = 5, /*!< The message couldn't be decrypted */
};
static std::size_t const MAX_RECEIVER_CHAINS = 5;
static std::size_t const MAX_SKIPPED_MESSAGE_KEYS = 40;
......@@ -124,12 +115,12 @@ struct Ratchet {
);
/** The number of bytes needed to persist the current session. */
std::size_t pickle_max_output_length();
std::size_t pickle_length();
/** Persists a session as a sequence of bytes
* Returns the number of output bytes used. */
std::size_t pickle(
std::uint8_t * output, std::size_t max_output_length
std::uint8_t * output, std::size_t output_length
);
/** Loads a session from a sequence of bytes.
......
#ifndef AXOLOTL_SESSION_HH_
#define AXOLOTL_SESSION_HH_
#include "axolotl/ratchet.hh"
namespace axolotl {
struct RemoteKey {
std::uint32_t id;
Curve25519PublicKey key;
};
struct RemoteKeys {
};
enum struct MessageType {
PRE_KEY_MESSAGE = 0,
MESSAGE = 1,
};
struct Session {
bool received_message;
RemoteKey alice_identity_key;
RemoteKey alice_base_key;
RemoteKey bob_identity_key;
RemoteKey bob_one_time_key;
Ratchet ratchet;
void initialise_outbound_session_random_length();
void initialise_outbound_session(
Account const & local_account,
RemoteKey const & identity_key,
RemoteKey const & one_time_key,
std::uint8_t const * random, std::size_t random_length
);
void initialise_inbound_session(
Account & local_account,
std::uint8_t const * one_time_key_message, std::size_t message_length
);
void matches_inbound_session(
std::uint8_t const * one_time_key_message, std::size_t message_length
);
MessageType encrypt_message_type();
std::size_t encrypt_message_length(
std::size_t plaintext_length
);
std::size_t encrypt_random_length();
std::size_t encrypt(
std::uint8_t const * plaintext, std::size_t plaintext_length,
std::uint8_t const * random, std::size_t random_length,
std::uint8_t * message, std::size_t message_length
);
std::size_t decrypt_max_plaintext_length(
MessageType message_type,
std::uint8_t const * message, std::size_t message_length
);
std::size_t decrypt(
MessageType message_type,
std::uint8_t const * message, std::size_t message_length,
std::uint8_t * plaintext, std::size_t max_plaintext_length
);
};
} // namespace axolotl
#endif /* AXOLOTL_SESSION_HH_ */
......@@ -215,11 +215,11 @@ void axolotl::Ratchet::initialise_as_alice(
}
std::size_t axolotl::Ratchet::pickle_max_output_length() {
std::size_t axolotl::Ratchet::pickle_length() {
std::size_t counter_length = 4;
std::size_t send_chain_length = counter_length + 64 + 32;
std::size_t recv_chain_length = counter_length + 32 + 32;
std::size_t skip_key_length = counter_length + 32 + 32 + 32 + 16;
std::size_t skip_key_length = counter_length + 32 + 32;
std::size_t pickle_length = 3 * counter_length + 32;
pickle_length += sender_chain.size() * send_chain_length;
pickle_length += receiver_chains.size() * recv_chain_length;
......@@ -265,10 +265,10 @@ std::uint8_t * unpickle_bytes(
std::size_t axolotl::Ratchet::pickle(
std::uint8_t * output, std::size_t max_output_length
std::uint8_t * output, std::size_t output_length
) {
std::uint8_t * pos = output;
if (max_output_length < pickle_max_output_length()) {
if (output_length < pickle_length()) {
last_error = axolotl::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
return std::size_t(-1);
}
......
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