Merge branch 'rav/c_bindings'

1 files changed, 423 insertions, 0 deletions

diff --git a/include/olm/olm.h b/include/olm/olm.h
new file mode 100644
index 0000000..8abac49
--- /dev/null
+++ b/include/olm/olm.h
@@ -0,0 +1,423 @@
+/* Copyright 2015, 2016 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.
+ */
+
+#ifndef OLM_H_
+#define OLM_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static const size_t OLM_MESSAGE_TYPE_PRE_KEY = 0;
+static const size_t OLM_MESSAGE_TYPE_MESSAGE = 1;
+
+typedef struct OlmAccount OlmAccount;
+typedef struct OlmSession OlmSession;
+typedef struct OlmUtility OlmUtility;
+
+/** The size of an account object in bytes */
+size_t olm_account_size();
+
+/** The size of a session object in bytes */
+size_t olm_session_size();
+
+/** The size of a utility object in bytes */
+size_t olm_utility_size();
+
+/** Initialise an account object using the supplied memory
+ *  The supplied memory must be at least olm_account_size() bytes */
+OlmAccount * olm_account(
+    void * memory
+);
+
+/** Initialise a session object using the supplied memory
+ *  The supplied memory must be at least olm_session_size() bytes */
+OlmSession * olm_session(
+    void * memory
+);
+
+/** Initialise a utility object using the supplied memory
+ *  The supplied memory must be at least olm_utility_size() bytes */
+OlmUtility * olm_utility(
+    void * memory
+);
+
+/** The value that olm will return from a function if there was an error */
+size_t olm_error();
+
+/** A null terminated string describing the most recent error to happen to an
+ * account */
+const char * olm_account_last_error(
+    OlmAccount * account
+);
+
+/** A null terminated string describing the most recent error to happen to a
+ * session */
+const char * olm_session_last_error(
+    OlmSession * session
+);
+
+/** A null terminated string describing the most recent error to happen to a
+ * utility */
+const char * olm_utility_last_error(
+    OlmUtility * utility
+);
+
+/** Clears the memory used to back this account */
+size_t olm_clear_account(
+    OlmAccount * account
+);
+
+/** Clears the memory used to back this session */
+size_t olm_clear_session(
+    OlmSession * session
+);
+
+/** Clears the memory used to back this utility */
+size_t olm_clear_utility(
+    OlmUtility * utility
+);
+
+/** Returns the number of bytes needed to store an account */
+size_t olm_pickle_account_length(
+    OlmAccount * account
+);
+
+/** Returns the number of bytes needed to store a session */
+size_t olm_pickle_session_length(
+    OlmSession * session
+);
+
+/** Stores an account as a base64 string. Encrypts the account using the
+ * supplied key. Returns the length of the pickled account on success.
+ * Returns olm_error() on failure. If the pickle output buffer
+ * is smaller than olm_pickle_account_length() then
+ * olm_account_last_error() will be "OUTPUT_BUFFER_TOO_SMALL" */
+size_t olm_pickle_account(
+    OlmAccount * account,
+    void const * key, size_t key_length,
+    void * pickled, size_t pickled_length
+);
+
+/** Stores a session as a base64 string. Encrypts the session using the
+ * supplied key. Returns the length of the pickled session on success.
+ * Returns olm_error() on failure. If the pickle output buffer
+ * is smaller than olm_pickle_session_length() then
+ * olm_session_last_error() will be "OUTPUT_BUFFER_TOO_SMALL" */
+size_t olm_pickle_session(
+    OlmSession * session,
+    void const * key, size_t key_length,
+    void * pickled, size_t pickled_length
+);
+
+/** Loads an account from a pickled base64 string. Decrypts the account using
+ * the supplied key. Returns olm_error() on failure. If the key doesn't
+ * match the one used to encrypt the account then olm_account_last_error()
+ * will be "BAD_ACCOUNT_KEY". If the base64 couldn't be decoded then
+ * olm_account_last_error() will be "INVALID_BASE64". The input pickled
+ * buffer is destroyed */
+size_t olm_unpickle_account(
+    OlmAccount * account,
+    void const * key, size_t key_length,
+    void * pickled, size_t pickled_length
+);
+
+/** Loads a session from a pickled base64 string. Decrypts the session using
+ * the supplied key. Returns olm_error() on failure. If the key doesn't
+ * match the one used to encrypt the account then olm_session_last_error()
+ * will be "BAD_ACCOUNT_KEY". If the base64 couldn't be decoded then
+ * olm_session_last_error() will be "INVALID_BASE64". The input pickled
+ * buffer is destroyed */
+size_t olm_unpickle_session(
+    OlmSession * session,
+    void const * key, size_t key_length,
+    void * pickled, size_t pickled_length
+);
+
+/** The number of random bytes needed to create an account.*/
+size_t olm_create_account_random_length(
+    OlmAccount * account
+);
+
+/** Creates a new account. Returns olm_error() on failure. If weren't
+ * enough random bytes then olm_account_last_error() will be
+ * "NOT_ENOUGH_RANDOM" */
+size_t olm_create_account(
+    OlmAccount * account,
+    void * random, size_t random_length
+);
+
+/** The size of the output buffer needed to hold the identity keys */
+size_t olm_account_identity_keys_length(
+    OlmAccount * account
+);
+
+/** Writes the public parts of the identity keys for the account into the
+ * identity_keys output buffer. Returns olm_error() on failure. If the
+ * identity_keys buffer was too small then olm_account_last_error() will be
+ * "OUTPUT_BUFFER_TOO_SMALL". */
+size_t olm_account_identity_keys(
+    OlmAccount * account,
+    void * identity_keys, size_t identity_key_length
+);
+
+
+/** The length of an ed25519 signature encoded as base64. */
+size_t olm_account_signature_length(
+    OlmAccount * account
+);
+
+/** Signs a message with the ed25519 key for this account. Returns olm_error()
+ * on failure. If the signature buffer was too small then
+ * olm_account_last_error() will be "OUTPUT_BUFFER_TOO_SMALL" */
+size_t olm_account_sign(
+    OlmAccount * account,
+    void const * message, size_t message_length,
+    void * signature, size_t signature_length
+);
+
+/** The size of the output buffer needed to hold the one time keys */
+size_t olm_account_one_time_keys_length(
+    OlmAccount * account
+);
+
+/** Writes the public parts of the unpublished one time keys for the account
+ * into the one_time_keys output buffer. Returns olm_error() on failure.
+ * If the one_time_keys buffer was too small then olm_account_last_error()
+ * will be "OUTPUT_BUFFER_TOO_SMALL". */
+size_t olm_account_one_time_keys(
+    OlmAccount * account,
+    void * one_time_keys, size_t one_time_keys_length
+);
+
+/** Marks the current set of one time keys as being published. */
+size_t olm_account_mark_keys_as_published(
+    OlmAccount * account
+);
+
+/** The largest number of one time keys this account can store. */
+size_t olm_account_max_number_of_one_time_keys(
+    OlmAccount * account
+);
+
+/** The number of random bytes needed to generate a given number of new one
+ * time keys. */
+size_t olm_account_generate_one_time_keys_random_length(
+    OlmAccount * account,
+    size_t number_of_keys
+);
+
+/** Generates a number of new one time keys. If the total number of keys stored
+ * by this account exceeds max_number_of_one_time_keys() then the old keys are
+ * discarded. Returns olm_error() on error. If the number of random bytes is
+ * too small then olm_account_last_error() will be "NOT_ENOUGH_RANDOM". */
+size_t olm_account_generate_one_time_keys(
+    OlmAccount * account,
+    size_t number_of_keys,
+    void * random, size_t random_length
+);
+
+/** The number of random bytes needed to create an outbound session */
+size_t olm_create_outbound_session_random_length(
+    OlmSession * session
+);
+
+/** Creates a new out-bound session for sending messages to a given identity_key
+ * and one_time_key. Returns olm_error() on failure. If the keys couldn't be
+ * decoded as base64 then olm_session_last_error() will be "INVALID_BASE64"
+ * If there weren't enough random bytes then olm_session_last_error() will
+ * be "NOT_ENOUGH_RANDOM". */
+size_t olm_create_outbound_session(
+    OlmSession * session,
+    OlmAccount * account,
+    void const * their_identity_key, size_t their_identity_key_length,
+    void const * their_one_time_key, size_t their_one_time_key_length,
+    void * random, size_t random_length
+);
+
+/** Create a new in-bound session for sending/receiving messages from an
+ * incoming PRE_KEY message. Returns olm_error() on failure. If the base64
+ * couldn't be decoded then olm_session_last_error will be "INVALID_BASE64".
+ * If the message was for an unsupported protocol version then
+ * olm_session_last_error() will be "BAD_MESSAGE_VERSION". If the message
+ * couldn't be decoded then then olm_session_last_error() will be
+ * "BAD_MESSAGE_FORMAT". If the message refers to an unknown one time
+ * key then olm_session_last_error() will be "BAD_MESSAGE_KEY_ID". */
+size_t olm_create_inbound_session(
+    OlmSession * session,
+    OlmAccount * account,
+    void * one_time_key_message, size_t message_length
+);
+
+/** Create a new in-bound session for sending/receiving messages from an
+ * incoming PRE_KEY message. Returns olm_error() on failure. If the base64
+ * couldn't be decoded then olm_session_last_error will be "INVALID_BASE64".
+ * If the message was for an unsupported protocol version then
+ * olm_session_last_error() will be "BAD_MESSAGE_VERSION". If the message
+ * couldn't be decoded then then olm_session_last_error() will be
+ * "BAD_MESSAGE_FORMAT". If the message refers to an unknown one time
+ * key then olm_session_last_error() will be "BAD_MESSAGE_KEY_ID". */
+size_t olm_create_inbound_session_from(
+    OlmSession * session,
+    OlmAccount * account,
+    void const * their_identity_key, size_t their_identity_key_length,
+    void * one_time_key_message, size_t message_length
+);
+
+/** The length of the buffer needed to return the id for this session. */
+size_t olm_session_id_length(
+    OlmSession * session
+);
+
+/** An identifier for this session. Will be the same for both ends of the
+ * conversation. If the id buffer is too small then olm_session_last_error()
+ * will be "OUTPUT_BUFFER_TOO_SMALL". */
+size_t olm_session_id(
+    OlmSession * session,
+    void * id, size_t id_length
+);
+
+/** Checks if the PRE_KEY message is for this in-bound session. This can happen
+ * if multiple messages are sent to this account before this account sends a
+ * message in reply. Returns olm_error() on failure. If the base64
+ * couldn't be decoded then olm_session_last_error will be "INVALID_BASE64".
+ * If the message was for an unsupported protocol version then
+ * olm_session_last_error() will be "BAD_MESSAGE_VERSION". If the message
+ * couldn't be decoded then then olm_session_last_error() will be
+ * "BAD_MESSAGE_FORMAT". */
+size_t olm_matches_inbound_session(
+    OlmSession * session,
+    void * one_time_key_message, size_t message_length
+);
+
+/** Checks if the PRE_KEY message is for this in-bound session. This can happen
+ * if multiple messages are sent to this account before this account sends a
+ * message in reply. Returns olm_error() on failure. If the base64
+ * couldn't be decoded then olm_session_last_error will be "INVALID_BASE64".
+ * If the message was for an unsupported protocol version then
+ * olm_session_last_error() will be "BAD_MESSAGE_VERSION". If the message
+ * couldn't be decoded then then olm_session_last_error() will be
+ * "BAD_MESSAGE_FORMAT". */
+size_t olm_matches_inbound_session_from(
+    OlmSession * session,
+    void const * their_identity_key, size_t their_identity_key_length,
+    void * one_time_key_message, size_t message_length
+);
+
+/** Removes the one time keys that the session used from the account. Returns
+ * olm_error() on failure. If the account doesn't have any matching one time
+ * keys then olm_account_last_error() will be "BAD_MESSAGE_KEY_ID". */
+size_t olm_remove_one_time_keys(
+    OlmAccount * account,
+    OlmSession * session
+);
+
+/** The type of the next message that olm_encrypt() will return. Returns
+ * OLM_MESSAGE_TYPE_PRE_KEY if the message will be a PRE_KEY message.
+ * Returns OLM_MESSAGE_TYPE_MESSAGE if the message will be a normal message.
+ * Returns olm_error on failure. */
+size_t olm_encrypt_message_type(
+    OlmSession * session
+);
+
+/** The number of random bytes needed to encrypt the next message. */
+size_t olm_encrypt_random_length(
+    OlmSession * session
+);
+
+/** The size of the next message in bytes for the given number of plain-text
+ * bytes. */
+size_t olm_encrypt_message_length(
+    OlmSession * session,
+    size_t plaintext_length
+);
+
+/** Encrypts a message using the session. Returns the length of the message in
+ * bytes on success. Writes the message as base64 into the message buffer.
+ * Returns olm_error() on failure. If the message buffer is too small then
+ * olm_session_last_error() will be "OUTPUT_BUFFER_TOO_SMALL". If there
+ * weren't enough random bytes then olm_session_last_error() will be
+ * "NOT_ENOUGH_RANDOM". */
+size_t olm_encrypt(
+    OlmSession * session,
+    void const * plaintext, size_t plaintext_length,
+    void * random, size_t random_length,
+    void * message, size_t message_length
+);
+
+/** The maximum number of bytes of plain-text a given message could decode to.
+ * The actual size could be different due to padding. The input message buffer
+ * is destroyed. Returns olm_error() on failure. If the message base64
+ * couldn't be decoded then olm_session_last_error() will be
+ * "INVALID_BASE64". If the message is for an unsupported version of the
+ * protocol then olm_session_last_error() will be "BAD_MESSAGE_VERSION".
+ * If the message couldn't be decoded then olm_session_last_error() will be
+ * "BAD_MESSAGE_FORMAT". */
+size_t olm_decrypt_max_plaintext_length(
+    OlmSession * session,
+    size_t message_type,
+    void * message, size_t message_length
+);
+
+/** Decrypts a message using the session. The input message buffer is destroyed.
+ * Returns the length of the plain-text on success. Returns olm_error() on
+ * failure. If the plain-text buffer is smaller than
+ * olm_decrypt_max_plaintext_length() then olm_session_last_error()
+ * will be "OUTPUT_BUFFER_TOO_SMALL". If the base64 couldn't be decoded then
+ * olm_session_last_error() will be "INVALID_BASE64". If the message is for
+ * an unsupported version of the protocol then olm_session_last_error() will
+ *  be "BAD_MESSAGE_VERSION". If the message couldn't be decoded then
+ *  olm_session_last_error() will be BAD_MESSAGE_FORMAT".
+ *  If the MAC on the message was invalid then olm_session_last_error() will
+ *  be "BAD_MESSAGE_MAC". */
+size_t olm_decrypt(
+    OlmSession * session,
+    size_t message_type,
+    void * message, size_t message_length,
+    void * plaintext, size_t max_plaintext_length
+);
+
+/** The length of the buffer needed to hold the SHA-256 hash. */
+size_t olm_sha256_length(
+   OlmUtility * utility
+);
+
+/** Calculates the SHA-256 hash of the input and encodes it as base64. If the
+ * output buffer is smaller than olm_sha256_length() then
+ * olm_session_last_error() will be "OUTPUT_BUFFER_TOO_SMALL". */
+size_t olm_sha256(
+    OlmUtility * utility,
+    void const * input, size_t input_length,
+    void * output, size_t output_length
+);
+
+/** Verify an ed25519 signature. If the key was too small then
+ * olm_session_last_error will be "INVALID_BASE64". If the signature was invalid
+ * then olm_session_last_error() will be "BAD_MESSAGE_MAC". */
+size_t olm_ed25519_verify(
+    OlmUtility * utility,
+    void const * key, size_t key_length,
+    void const * message, size_t message_length,
+    void * signature, size_t signature_length
+);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* OLM_HH_ */