Rename axolotlpp as olm to avoid confusion with Axolotl-the-spec and Axolotl-the-OWS-libraries at moxie's request

1 files changed, 580 insertions, 0 deletions

diff --git a/src/olm.cpp b/src/olm.cpp
new file mode 100644
index 0000000..f5425fa
--- /dev/null
+++ b/src/olm.cpp
@@ -0,0 +1,580 @@
+/* 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 "olm/olm.hh"
+#include "olm/session.hh"
+#include "olm/account.hh"
+#include "olm/base64.hh"
+#include "olm/cipher.hh"
+
+#include <new>
+#include <cstring>
+
+namespace {
+
+static OlmAccount * to_c(olm::Account * account) {
+    return reinterpret_cast<OlmAccount *>(account);
+}
+
+static OlmSession * to_c(olm::Session * account) {
+    return reinterpret_cast<OlmSession *>(account);
+}
+
+static olm::Account * from_c(OlmAccount * account) {
+    return reinterpret_cast<olm::Account *>(account);
+}
+
+static olm::Session * from_c(OlmSession * account) {
+    return reinterpret_cast<olm::Session *>(account);
+}
+
+static std::uint8_t * from_c(void * bytes) {
+    return reinterpret_cast<std::uint8_t *>(bytes);
+}
+
+static std::uint8_t const * from_c(void const * bytes) {
+    return reinterpret_cast<std::uint8_t const *>(bytes);
+}
+
+static const std::uint8_t CIPHER_KDF_INFO[] = "Pickle";
+
+static const olm::CipherAesSha256 PICKLE_CIPHER(
+    CIPHER_KDF_INFO, sizeof(CIPHER_KDF_INFO) -1
+);
+
+std::size_t enc_output_length(
+    size_t raw_length
+) {
+    std::size_t length = PICKLE_CIPHER.encrypt_ciphertext_length(raw_length);
+    length += PICKLE_CIPHER.mac_length();
+    return olm::encode_base64_length(length);
+}
+
+
+std::uint8_t * enc_output_pos(
+    std::uint8_t * output,
+    size_t raw_length
+) {
+    std::size_t length = PICKLE_CIPHER.encrypt_ciphertext_length(raw_length);
+    length += PICKLE_CIPHER.mac_length();
+    return output + olm::encode_base64_length(length) - length;
+}
+
+std::size_t enc_output(
+    std::uint8_t const * key, std::size_t key_length,
+    std::uint8_t * output, size_t raw_length
+) {
+    std::size_t ciphertext_length = PICKLE_CIPHER.encrypt_ciphertext_length(
+        raw_length
+    );
+    std::size_t length = ciphertext_length + PICKLE_CIPHER.mac_length();
+    std::size_t base64_length = olm::encode_base64_length(length);
+    std::uint8_t * raw_output = output + base64_length - length;
+    PICKLE_CIPHER.encrypt(
+        key, key_length,
+        raw_output, raw_length,
+        raw_output, ciphertext_length,
+        raw_output, length
+    );
+    olm::encode_base64(raw_output, length, output);
+    return raw_length;
+}
+
+std::size_t enc_input(
+    std::uint8_t const * key, std::size_t key_length,
+    std::uint8_t * input, size_t b64_length,
+    olm::ErrorCode & last_error
+) {
+    std::size_t enc_length = olm::decode_base64_length(b64_length);
+    if (enc_length == std::size_t(-1)) {
+        last_error = olm::ErrorCode::INVALID_BASE64;
+        return std::size_t(-1);
+    }
+    olm::decode_base64(input, b64_length, input);
+    std::size_t raw_length = enc_length - PICKLE_CIPHER.mac_length();
+    std::size_t result = PICKLE_CIPHER.decrypt(
+        key, key_length,
+        input, enc_length,
+        input, raw_length,
+        input, raw_length
+    );
+    if (result == std::size_t(-1)) {
+        last_error = olm::ErrorCode::BAD_ACCOUNT_KEY;
+    }
+    return result;
+}
+
+
+std::size_t b64_output_length(
+    size_t raw_length
+) {
+    return olm::encode_base64_length(raw_length);
+}
+
+std::uint8_t * b64_output_pos(
+    std::uint8_t * output,
+    size_t raw_length
+) {
+    return output + olm::encode_base64_length(raw_length) - raw_length;
+}
+
+std::size_t b64_output(
+    std::uint8_t * output, size_t raw_length
+) {
+    std::size_t base64_length = olm::encode_base64_length(raw_length);
+    std::uint8_t * raw_output = output + base64_length - raw_length;
+    olm::encode_base64(raw_output, raw_length, output);
+    return base64_length;
+}
+
+std::size_t b64_input(
+    std::uint8_t * input, size_t b64_length,
+    olm::ErrorCode & last_error
+) {
+    std::size_t raw_length = olm::decode_base64_length(b64_length);
+    if (raw_length == std::size_t(-1)) {
+        last_error = olm::ErrorCode::INVALID_BASE64;
+        return std::size_t(-1);
+    }
+    olm::decode_base64(input, b64_length, input);
+    return raw_length;
+}
+
+const char * errors[9] {
+    "SUCCESS",
+    "NOT_ENOUGH_RANDOM",
+    "OUTPUT_BUFFER_TOO_SMALL",
+    "BAD_MESSAGE_VERSION",
+    "BAD_MESSAGE_FORMAT",
+    "BAD_MESSAGE_MAC",
+    "BAD_MESSAGE_KEY_ID",
+    "INVALID_BASE64",
+    "BAD_ACCOUNT_KEY",
+};
+
+} // namespace
+
+
+extern "C" {
+
+
+size_t olm_error() {
+    return std::size_t(-1);
+}
+
+
+const char * olm_account_last_error(
+    OlmSession * account
+) {
+    unsigned error = unsigned(from_c(account)->last_error);
+    if (error < 9) {
+        return errors[error];
+    } else {
+        return "UNKNOWN_ERROR";
+    }
+}
+
+
+const char * olm_session_last_error(
+    OlmSession * session
+) {
+    unsigned error = unsigned(from_c(session)->last_error);
+    if (error < 9) {
+        return errors[error];
+    } else {
+        return "UNKNOWN_ERROR";
+    }
+}
+
+
+size_t olm_account_size() {
+    return sizeof(olm::Account);
+}
+
+
+size_t olm_session_size() {
+    return sizeof(olm::Session);
+}
+
+
+OlmAccount * olm_account(
+    void * memory
+) {
+    return to_c(new(memory) olm::Account());
+}
+
+
+OlmSession * olm_session(
+    void * memory
+) {
+    return to_c(new(memory) olm::Session());
+}
+
+
+size_t olm_pickle_account_length(
+    OlmAccount * account
+) {
+    return enc_output_length(pickle_length(*from_c(account)));
+}
+
+
+size_t olm_pickle_session_length(
+    OlmSession * session
+) {
+    return enc_output_length(pickle_length(*from_c(session)));
+}
+
+
+size_t olm_pickle_account(
+    OlmAccount * account,
+    void const * key, size_t key_length,
+    void * pickled, size_t pickled_length
+) {
+    olm::Account & object = *from_c(account);
+    std::size_t raw_length = pickle_length(object);
+    if (pickled_length < enc_output_length(raw_length)) {
+        object.last_error = olm::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
+        return size_t(-1);
+    }
+    pickle(enc_output_pos(from_c(pickled), raw_length), object);
+    return enc_output(from_c(key), key_length, from_c(pickled), raw_length);
+}
+
+
+size_t olm_pickle_session(
+    OlmSession * session,
+    void const * key, size_t key_length,
+    void * pickled, size_t pickled_length
+) {
+    olm::Session & object = *from_c(session);
+    std::size_t raw_length = pickle_length(object);
+    if (pickled_length < enc_output_length(raw_length)) {
+        object.last_error = olm::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
+        return size_t(-1);
+    }
+    pickle(enc_output_pos(from_c(pickled), raw_length), object);
+    return enc_output(from_c(key), key_length, from_c(pickled), raw_length);
+}
+
+
+size_t olm_unpickle_account(
+    OlmAccount * account,
+    void const * key, size_t key_length,
+    void * pickled, size_t pickled_length
+) {
+    olm::Account & object = *from_c(account);
+    std::uint8_t * const pos = from_c(pickled);
+    std::size_t raw_length = enc_input(
+        from_c(key), key_length, pos, pickled_length, object.last_error
+    );
+    if (raw_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+    std::uint8_t * const end = pos + raw_length;
+    unpickle(pos, end, object);
+    return pickled_length;
+}
+
+
+size_t olm_unpickle_session(
+    OlmSession * session,
+    void const * key, size_t key_length,
+    void * pickled, size_t pickled_length
+) {
+    olm::Session & object = *from_c(session);
+    std::uint8_t * const pos = from_c(pickled);
+    std::size_t raw_length = enc_input(
+        from_c(key), key_length, pos, pickled_length, object.last_error
+    );
+    if (raw_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+    std::uint8_t * const end = pos + raw_length;
+    unpickle(pos, end, object);
+    return pickled_length;
+}
+
+
+size_t olm_create_account_random_length(
+    OlmAccount * account
+) {
+    return from_c(account)->new_account_random_length();
+}
+
+
+size_t olm_create_account(
+    OlmAccount * account,
+    void const * random, size_t random_length
+) {
+    return from_c(account)->new_account(from_c(random), random_length);
+}
+
+namespace {
+
+static const std::size_t OUTPUT_KEY_LENGTH = 2 + 10 + 2 +
+        olm::encode_base64_length(32) + 3;
+
+void output_key(
+    olm::LocalKey const & key,
+    std::uint8_t sep,
+    std::uint8_t * output
+) {
+    output[0] = sep;
+    output[1] = '[';
+    std::memset(output + 2, ' ', 10);
+    uint32_t value = key.id;
+    uint8_t * number = output + 11;
+    *number = '0' + value % 10;
+    value /= 10;
+    while (value) {
+        *(--number) = '0' + value % 10;
+        value /= 10;
+    }
+    output[12] = ',';
+    output[13] = '"';
+    olm::encode_base64(key.key.public_key, 32, output + 14);
+    output[OUTPUT_KEY_LENGTH - 3] = '"';
+    output[OUTPUT_KEY_LENGTH - 2] = ']';
+    output[OUTPUT_KEY_LENGTH - 1] = '\n';
+}
+
+} // namespace
+
+
+size_t olm_account_identity_keys_length(
+    OlmAccount * account
+) {
+    return OUTPUT_KEY_LENGTH + 1;
+}
+
+
+size_t olm_account_identity_keys(
+    OlmAccount * account,
+    void * identity_keys, size_t identity_key_length
+) {
+    std::size_t length = olm_account_identity_keys_length(account);
+    if (identity_key_length < length) {
+        from_c(account)->last_error =
+            olm::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
+        return size_t(-1);
+    }
+    std::uint8_t * output = from_c(identity_keys);
+    output_key(from_c(account)->identity_key, '[', output);
+    output += OUTPUT_KEY_LENGTH;
+    output[0] = ']';
+    return length;
+}
+
+
+size_t olm_account_one_time_keys_length(
+    OlmAccount * account
+) {
+    size_t count = from_c(account)->one_time_keys.size();
+    return OUTPUT_KEY_LENGTH * (count + 1) + 1;
+}
+
+
+size_t olm_account_one_time_keys(
+    OlmAccount * account,
+    void * identity_keys, size_t identity_key_length
+) {
+    std::size_t length = olm_account_one_time_keys_length(account);
+    if (identity_key_length < length) {
+        from_c(account)->last_error =
+            olm::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
+        return size_t(-1);
+    }
+    std::uint8_t * output = from_c(identity_keys);
+    output_key(from_c(account)->last_resort_one_time_key, '[', output);
+    output += OUTPUT_KEY_LENGTH;
+    for (auto const & key : from_c(account)->one_time_keys) {
+        output_key(key, ',', output);
+        output += OUTPUT_KEY_LENGTH;
+    }
+    output[0] = ']';
+    return length;
+}
+
+
+size_t olm_create_outbound_session_random_length(
+    OlmSession * session
+) {
+    return from_c(session)->new_outbound_session_random_length();
+}
+
+size_t olm_create_outbound_session(
+    OlmSession * session,
+    OlmAccount * account,
+    void const * their_identity_key, size_t their_identity_key_length,
+    unsigned their_one_time_key_id,
+    void const * their_one_time_key, size_t their_one_time_key_length,
+    void const * random, size_t random_length
+) {
+    if (olm::decode_base64_length(their_identity_key_length) != 32
+            || olm::decode_base64_length(their_one_time_key_length) != 32
+    ) {
+        from_c(session)->last_error = olm::ErrorCode::INVALID_BASE64;
+        return std::size_t(-1);
+    }
+    olm::Curve25519PublicKey identity_key;
+    olm::RemoteKey one_time_key;
+
+    olm::decode_base64(
+        from_c(their_identity_key), their_identity_key_length,
+        identity_key.public_key
+    );
+    one_time_key.id = their_one_time_key_id;
+    olm::decode_base64(
+        from_c(their_one_time_key), their_one_time_key_length,
+        one_time_key.key.public_key
+    );
+
+    return from_c(session)->new_outbound_session(
+        *from_c(account), identity_key, one_time_key,
+        from_c(random), random_length
+    );
+}
+
+
+size_t olm_create_inbound_session(
+    OlmSession * session,
+    OlmAccount * account,
+    void * one_time_key_message, size_t message_length
+) {
+    std::size_t raw_length = b64_input(
+        from_c(one_time_key_message), message_length, from_c(session)->last_error
+    );
+    if (raw_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+    return from_c(session)->new_inbound_session(
+        *from_c(account), from_c(one_time_key_message), raw_length
+    );
+}
+
+
+size_t olm_matches_inbound_session(
+    OlmSession * session,
+    void * one_time_key_message, size_t message_length
+) {
+    std::size_t raw_length = b64_input(
+        from_c(one_time_key_message), message_length, from_c(session)->last_error
+    );
+    if (raw_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+    bool matches = from_c(session)->matches_inbound_session(
+        from_c(one_time_key_message), raw_length
+    );
+    return matches ? 1 : 0;
+}
+
+
+size_t olm_remove_one_time_keys(
+    OlmAccount * account,
+    OlmSession * session
+) {
+    size_t result = from_c(account)->remove_key(
+        from_c(session)->bob_one_time_key_id
+    );
+    if (result == std::size_t(-1)) {
+        from_c(account)->last_error = olm::ErrorCode::BAD_MESSAGE_KEY_ID;
+    }
+    return result;
+}
+
+
+size_t olm_encrypt_message_type(
+    OlmSession * session
+) {
+    return size_t(from_c(session)->encrypt_message_type());
+}
+
+
+size_t olm_encrypt_random_length(
+    OlmSession * session
+) {
+    return from_c(session)->encrypt_random_length();
+}
+
+
+size_t olm_encrypt_message_length(
+    OlmSession * session,
+    size_t plaintext_length
+) {
+    return b64_output_length(
+        from_c(session)->encrypt_message_length(plaintext_length)
+    );
+}
+
+
+size_t olm_encrypt(
+    OlmSession * session,
+    void const * plaintext, size_t plaintext_length,
+    void const * random, size_t random_length,
+    void * message, size_t message_length
+) {
+    std::size_t raw_length = from_c(session)->encrypt_message_length(
+        plaintext_length
+    );
+    if (message_length < raw_length) {
+        from_c(session)->last_error =
+            olm::ErrorCode::OUTPUT_BUFFER_TOO_SMALL;
+        return std::size_t(-1);
+    }
+    from_c(session)->encrypt(
+        from_c(plaintext), plaintext_length,
+        from_c(random), random_length,
+        b64_output_pos(from_c(message), raw_length), raw_length
+    );
+    return b64_output(from_c(message), raw_length);
+}
+
+
+size_t olm_decrypt_max_plaintext_length(
+    OlmSession * session,
+    size_t message_type,
+    void * message, size_t message_length
+) {
+    std::size_t raw_length = b64_input(
+        from_c(message), message_length, from_c(session)->last_error
+    );
+    if (raw_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+    return from_c(session)->decrypt_max_plaintext_length(
+        olm::MessageType(message_type), from_c(message), raw_length
+    );
+}
+
+
+size_t olm_decrypt(
+    OlmSession * session,
+    size_t message_type,
+    void * message, size_t message_length,
+    void * plaintext, size_t max_plaintext_length
+) {
+    std::size_t raw_length = b64_input(
+        from_c(message), message_length, from_c(session)->last_error
+    );
+    if (raw_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+    return from_c(session)->decrypt(
+        olm::MessageType(message_type), from_c(message), raw_length,
+        from_c(plaintext), max_plaintext_length
+    );
+}
+
+}