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Diffstat (limited to 'include/axolotl/axolotl.hh')
| -rw-r--r-- | include/axolotl/axolotl.hh | 167 |
1 files changed, 0 insertions, 167 deletions
diff --git a/include/axolotl/axolotl.hh b/include/axolotl/axolotl.hh deleted file mode 100644 index 9d7ff9a..0000000 --- a/include/axolotl/axolotl.hh +++ /dev/null @@ -1,167 +0,0 @@ -/* Copyright 2015 OpenMarket Ltd - * - * 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 - * - * http://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 "axolotl/crypto.hh" -#include "axolotl/list.hh" - -namespace axolotl { - -typedef std::uint8_t SharedKey[32]; - - -struct ChainKey { - std::uint32_t index; - SharedKey key; -}; - - -struct MessageKey { - std::uint32_t index; - Aes256Key cipher_key; - SharedKey mac_key; - Aes256Iv iv; -}; - - -struct SenderChain { - Curve25519KeyPair ratchet_key; - ChainKey chain_key; -}; - - -struct ReceiverChain { - Curve25519PublicKey ratchet_key; - ChainKey chain_key; -}; - - -struct SkippedMessageKey { - Curve25519PublicKey ratchet_key; - MessageKey message_key; -}; - - -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; - - -struct KdfInfo { - std::uint8_t const * root_info; - std::size_t root_info_length; - std::uint8_t const * ratchet_info; - std::size_t ratchet_info_length; - std::uint8_t const * message_info; - std::size_t message_info_length; -}; - - -struct Session { - - Session( - KdfInfo const & kdf_info - ); - - /** A some strings identifing the application to feed into the KDF. */ - KdfInfo kdf_info; - - /** The last error that happened encypting or decrypting a message. */ - ErrorCode last_error; - - /** The root key is used to generate chain keys from the ephemeral keys. - * A new root_key derived each time a chain key is derived. */ - SharedKey root_key; - - /** The sender chain is used to send messages. Each time a new ephemeral - * key is received from the remote server we generate a new sender chain - * with a new empheral key when we next send a message. */ - List<SenderChain, 1> sender_chain; - - /** The receiver chain is used to decrypt recieved messages. We store the - * last few chains so we can decrypt any out of order messages we haven't - * received yet. */ - List<ReceiverChain, MAX_RECEIVER_CHAINS> receiver_chains; - - /** List of message keys we've skipped over when advancing the receiver - * chain. */ - List<SkippedMessageKey, MAX_SKIPPED_MESSAGE_KEYS> skipped_message_keys; - - /** Initialise the session using a shared secret and the public part of the - * remote's first ratchet key */ - void initialise_as_bob( - std::uint8_t const * shared_secret, std::size_t shared_secret_length, - Curve25519PublicKey const & their_ratchet_key - ); - - /** Intialise the session using a shared secret and the public/private key - * pair for the first ratchet key */ - void initialise_as_alice( - std::uint8_t const * shared_secret, std::size_t shared_secret_length, - Curve25519KeyPair const & our_ratchet_key - ); - - /** The maximum number of bytes of output the encrypt method will write for - * a given message length. */ - std::size_t encrypt_max_output_length( - std::size_t plaintext_length - ); - - /** The number of bytes of random data the encrypt method will need to - * encrypt a message. This will be 32 bytes if the session needs to - * generate a new ephemeral key, or will be 0 bytes otherwise.*/ - std::size_t encrypt_random_length(); - - /** Encrypt some plaintext. Returns the length of the encrypted message - * or std::size_t(-1) on failure. On failure last_error will be set with - * an error code. The last_error will be NOT_ENOUGH_RANDOM if the number - * of random bytes is too small. The last_error will be - * OUTPUT_BUFFER_TOO_SMALL if the output buffer is too small. */ - 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 * output, std::size_t max_output_length - ); - - /** An upper bound on the number of bytes of plaintext the decrypt method - * will write for a given input message length. */ - std::size_t decrypt_max_plaintext_length( - std::size_t input_length - ); - - /** Decrypt a message. Returns the length of the decrypted plaintext or - * std::size_t(-1) on failure. On failure last_error will be set with an - * error code. The last_error will be OUTPUT_BUFFER_TOO_SMALL if the - * plaintext buffer is too small. The last_error will be - * BAD_MESSAGE_VERSION if the message was encrypted with an unsupported - * version of the protocol. The last_error will be BAD_MESSAGE_FORMAT if - * the message headers could not be decoded. The last_error will be - * BAD_MESSAGE_MAC if the message could not be verified */ - std::size_t decrypt( - std::uint8_t const * input, std::size_t input_length, - std::uint8_t * plaintext, std::size_t max_plaintext_length - ); -}; - - -} // namespace axolotl |