X-Git-Url: https://gitweb.ps.run/matrix_esp_thesis/blobdiff_plain/21c6e8484b0bd05c27e5a91f2884d431926adc61..da776f86b42946715c27edd64f7558b9d5080df1:/ext/olm/src/olm.cpp

diff --git a/ext/olm/src/olm.cpp b/ext/olm/src/olm.cpp
new file mode 100644
index 0000000..3a30f7a
--- /dev/null
+++ b/ext/olm/src/olm.cpp
@@ -0,0 +1,846 @@
+/* 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.h"
+#include "olm/session.hh"
+#include "olm/account.hh"
+#include "olm/cipher.h"
+#include "olm/pickle_encoding.h"
+#include "olm/utility.hh"
+#include "olm/base64.hh"
+#include "olm/memory.hh"
+
+#include <new>
+#include <cstring>
+
+namespace {
+
+static OlmAccount * to_c(olm::Account * account) {
+    return reinterpret_cast<OlmAccount *>(account);
+}
+
+static OlmSession * to_c(olm::Session * session) {
+    return reinterpret_cast<OlmSession *>(session);
+}
+
+static OlmUtility * to_c(olm::Utility * utility) {
+    return reinterpret_cast<OlmUtility *>(utility);
+}
+
+static olm::Account * from_c(OlmAccount * account) {
+    return reinterpret_cast<olm::Account *>(account);
+}
+
+static const olm::Account * from_c(OlmAccount const * account) {
+    return reinterpret_cast<olm::Account const *>(account);
+}
+
+static olm::Session * from_c(OlmSession * session) {
+    return reinterpret_cast<olm::Session *>(session);
+}
+
+static const olm::Session * from_c(OlmSession const * session) {
+    return reinterpret_cast<const olm::Session *>(session);
+}
+
+static olm::Utility * from_c(OlmUtility * utility) {
+    return reinterpret_cast<olm::Utility *>(utility);
+}
+
+static const olm::Utility * from_c(OlmUtility const * utility) {
+    return reinterpret_cast<const olm::Utility *>(utility);
+}
+
+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);
+}
+
+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,
+    OlmErrorCode & last_error
+) {
+    std::size_t raw_length = olm::decode_base64_length(b64_length);
+    if (raw_length == std::size_t(-1)) {
+        last_error = OlmErrorCode::OLM_INVALID_BASE64;
+        return std::size_t(-1);
+    }
+    olm::decode_base64(input, b64_length, input);
+    return raw_length;
+}
+
+} // namespace
+
+
+extern "C" {
+
+void olm_get_library_version(uint8_t *major, uint8_t *minor, uint8_t *patch) {
+    if (major != NULL) *major = OLMLIB_VERSION_MAJOR;
+    if (minor != NULL) *minor = OLMLIB_VERSION_MINOR;
+    if (patch != NULL) *patch = OLMLIB_VERSION_PATCH;
+}
+
+size_t olm_error(void) {
+    return std::size_t(-1);
+}
+
+
+const char * olm_account_last_error(
+    const OlmAccount * account
+) {
+    auto error = from_c(account)->last_error;
+    return _olm_error_to_string(error);
+}
+
+enum OlmErrorCode olm_account_last_error_code(
+    const OlmAccount * account
+) {
+    return from_c(account)->last_error;
+}
+
+const char * olm_session_last_error(
+    const OlmSession * session
+) {
+    auto error = from_c(session)->last_error;
+    return _olm_error_to_string(error);
+}
+
+enum OlmErrorCode olm_session_last_error_code(
+    OlmSession const * session
+) {
+    return from_c(session)->last_error;
+}
+
+const char * olm_utility_last_error(
+    OlmUtility const * utility
+) {
+    auto error = from_c(utility)->last_error;
+    return _olm_error_to_string(error);
+}
+
+enum OlmErrorCode olm_utility_last_error_code(
+    OlmUtility const * utility
+) {
+    return from_c(utility)->last_error;
+}
+
+size_t olm_account_size(void) {
+    return sizeof(olm::Account);
+}
+
+
+size_t olm_session_size(void) {
+    return sizeof(olm::Session);
+}
+
+size_t olm_utility_size(void) {
+    return sizeof(olm::Utility);
+}
+
+OlmAccount * olm_account(
+    void * memory
+) {
+    olm::unset(memory, sizeof(olm::Account));
+    return to_c(new(memory) olm::Account());
+}
+
+
+OlmSession * olm_session(
+    void * memory
+) {
+    olm::unset(memory, sizeof(olm::Session));
+    return to_c(new(memory) olm::Session());
+}
+
+
+OlmUtility * olm_utility(
+    void * memory
+) {
+    olm::unset(memory, sizeof(olm::Utility));
+    return to_c(new(memory) olm::Utility());
+}
+
+
+size_t olm_clear_account(
+    OlmAccount * account
+) {
+    /* Clear the memory backing the account  */
+    olm::unset(account, sizeof(olm::Account));
+    /* Initialise a fresh account object in case someone tries to use it */
+    new(account) olm::Account();
+    return sizeof(olm::Account);
+}
+
+
+size_t olm_clear_session(
+    OlmSession * session
+) {
+    /* Clear the memory backing the session */
+    olm::unset(session, sizeof(olm::Session));
+    /* Initialise a fresh session object in case someone tries to use it */
+    new(session) olm::Session();
+    return sizeof(olm::Session);
+}
+
+
+size_t olm_clear_utility(
+    OlmUtility * utility
+) {
+    /* Clear the memory backing the session */
+    olm::unset(utility, sizeof(olm::Utility));
+    /* Initialise a fresh session object in case someone tries to use it */
+    new(utility) olm::Utility();
+    return sizeof(olm::Utility);
+}
+
+
+size_t olm_pickle_account_length(
+    OlmAccount const * account
+) {
+    return _olm_enc_output_length(pickle_length(*from_c(account)));
+}
+
+
+size_t olm_pickle_session_length(
+    OlmSession const * session
+) {
+    return _olm_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 < _olm_enc_output_length(raw_length)) {
+        object.last_error = OlmErrorCode::OLM_OUTPUT_BUFFER_TOO_SMALL;
+        return size_t(-1);
+    }
+    pickle(_olm_enc_output_pos(from_c(pickled), raw_length), object);
+    return _olm_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 < _olm_enc_output_length(raw_length)) {
+        object.last_error = OlmErrorCode::OLM_OUTPUT_BUFFER_TOO_SMALL;
+        return size_t(-1);
+    }
+    pickle(_olm_enc_output_pos(from_c(pickled), raw_length), object);
+    return _olm_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 * input = from_c(pickled);
+    std::size_t raw_length = _olm_enc_input(
+        from_c(key), key_length, input, pickled_length, &object.last_error
+    );
+    if (raw_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+
+    std::uint8_t const * pos = input;
+    std::uint8_t const * end = pos + raw_length;
+
+    pos = unpickle(pos, end, object);
+
+    if (!pos) {
+        /* Input was corrupted. */
+        if (object.last_error == OlmErrorCode::OLM_SUCCESS) {
+            object.last_error = OlmErrorCode::OLM_CORRUPTED_PICKLE;
+        }
+        return std::size_t(-1);
+    } else if (pos != end) {
+        /* Input was longer than expected. */
+        object.last_error = OlmErrorCode::OLM_PICKLE_EXTRA_DATA;
+        return std::size_t(-1);
+    }
+
+    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 * input = from_c(pickled);
+    std::size_t raw_length = _olm_enc_input(
+        from_c(key), key_length, input, pickled_length, &object.last_error
+    );
+    if (raw_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+
+    std::uint8_t const * pos = input;
+    std::uint8_t const * end = pos + raw_length;
+
+    pos = unpickle(pos, end, object);
+
+    if (!pos) {
+        /* Input was corrupted. */
+        if (object.last_error == OlmErrorCode::OLM_SUCCESS) {
+            object.last_error = OlmErrorCode::OLM_CORRUPTED_PICKLE;
+        }
+        return std::size_t(-1);
+    } else if (pos != end) {
+        /* Input was longer than expected. */
+        object.last_error = OlmErrorCode::OLM_PICKLE_EXTRA_DATA;
+        return std::size_t(-1);
+    }
+
+    return pickled_length;
+}
+
+
+size_t olm_create_account_random_length(
+    OlmAccount const * account
+) {
+    return from_c(account)->new_account_random_length();
+}
+
+
+size_t olm_create_account(
+    OlmAccount * account,
+    void * random, size_t random_length
+) {
+    size_t result = from_c(account)->new_account(from_c(random), random_length);
+    olm::unset(random, random_length);
+    return result;
+}
+
+
+size_t olm_account_identity_keys_length(
+    OlmAccount const * account
+) {
+    return from_c(account)->get_identity_json_length();
+}
+
+
+size_t olm_account_identity_keys(
+    OlmAccount * account,
+    void * identity_keys, size_t identity_key_length
+) {
+    return from_c(account)->get_identity_json(
+        from_c(identity_keys), identity_key_length
+    );
+}
+
+
+size_t olm_account_signature_length(
+    OlmAccount const * account
+) {
+    return b64_output_length(from_c(account)->signature_length());
+}
+
+
+size_t olm_account_sign(
+    OlmAccount * account,
+    void const * message, size_t message_length,
+    void * signature, size_t signature_length
+) {
+    std::size_t raw_length = from_c(account)->signature_length();
+    if (signature_length < b64_output_length(raw_length)) {
+        from_c(account)->last_error =
+            OlmErrorCode::OLM_OUTPUT_BUFFER_TOO_SMALL;
+        return std::size_t(-1);
+    }
+    from_c(account)->sign(
+         from_c(message), message_length,
+         b64_output_pos(from_c(signature), raw_length), raw_length
+    );
+    return b64_output(from_c(signature), raw_length);
+}
+
+
+size_t olm_account_one_time_keys_length(
+    OlmAccount const * account
+) {
+    return from_c(account)->get_one_time_keys_json_length();
+}
+
+
+size_t olm_account_one_time_keys(
+    OlmAccount * account,
+    void * one_time_keys_json, size_t one_time_key_json_length
+) {
+    return from_c(account)->get_one_time_keys_json(
+        from_c(one_time_keys_json), one_time_key_json_length
+    );
+}
+
+
+size_t olm_account_mark_keys_as_published(
+    OlmAccount * account
+) {
+    return from_c(account)->mark_keys_as_published();
+}
+
+
+size_t olm_account_max_number_of_one_time_keys(
+    OlmAccount const * account
+) {
+    return from_c(account)->max_number_of_one_time_keys();
+}
+
+
+size_t olm_account_generate_one_time_keys_random_length(
+    OlmAccount const * account,
+    size_t number_of_keys
+) {
+    return from_c(account)->generate_one_time_keys_random_length(number_of_keys);
+}
+
+
+size_t olm_account_generate_one_time_keys(
+    OlmAccount * account,
+    size_t number_of_keys,
+    void * random, size_t random_length
+) {
+    size_t result = from_c(account)->generate_one_time_keys(
+        number_of_keys,
+        from_c(random), random_length
+    );
+    olm::unset(random, random_length);
+    return result;
+}
+
+
+size_t olm_account_generate_fallback_key_random_length(
+    OlmAccount const * account
+) {
+    return from_c(account)->generate_fallback_key_random_length();
+}
+
+
+size_t olm_account_generate_fallback_key(
+    OlmAccount * account,
+    void * random, size_t random_length
+) {
+    size_t result = from_c(account)->generate_fallback_key(
+        from_c(random), random_length
+    );
+    olm::unset(random, random_length);
+    return result;
+}
+
+
+size_t olm_account_fallback_key_length(
+    OlmAccount const * account
+) {
+    return from_c(account)->get_fallback_key_json_length();
+}
+
+
+size_t olm_account_fallback_key(
+    OlmAccount * account,
+    void * fallback_key_json, size_t fallback_key_json_length
+) {
+    return from_c(account)->get_fallback_key_json(
+        from_c(fallback_key_json), fallback_key_json_length
+    );
+}
+
+
+size_t olm_account_unpublished_fallback_key_length(
+    OlmAccount const * account
+) {
+    return from_c(account)->get_unpublished_fallback_key_json_length();
+}
+
+
+size_t olm_account_unpublished_fallback_key(
+    OlmAccount * account,
+    void * fallback_key_json, size_t fallback_key_json_length
+) {
+    return from_c(account)->get_unpublished_fallback_key_json(
+        from_c(fallback_key_json), fallback_key_json_length
+    );
+}
+
+
+void olm_account_forget_old_fallback_key(
+    OlmAccount * account
+) {
+    return from_c(account)->forget_old_fallback_key();
+}
+
+
+size_t olm_create_outbound_session_random_length(
+    OlmSession const * session
+) {
+    return from_c(session)->new_outbound_session_random_length();
+}
+
+
+size_t olm_create_outbound_session(
+    OlmSession * session,
+    OlmAccount const * 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
+) {
+    std::uint8_t const * id_key = from_c(their_identity_key);
+    std::uint8_t const * ot_key = from_c(their_one_time_key);
+    std::size_t id_key_length = their_identity_key_length;
+    std::size_t ot_key_length = their_one_time_key_length;
+
+    if (olm::decode_base64_length(id_key_length) != CURVE25519_KEY_LENGTH
+            || olm::decode_base64_length(ot_key_length) != CURVE25519_KEY_LENGTH
+    ) {
+        from_c(session)->last_error = OlmErrorCode::OLM_INVALID_BASE64;
+        return std::size_t(-1);
+    }
+    _olm_curve25519_public_key identity_key;
+    _olm_curve25519_public_key one_time_key;
+
+    olm::decode_base64(id_key, id_key_length, identity_key.public_key);
+    olm::decode_base64(ot_key, ot_key_length, one_time_key.public_key);
+
+    size_t result = from_c(session)->new_outbound_session(
+        *from_c(account), identity_key, one_time_key,
+        from_c(random), random_length
+    );
+    olm::unset(random, random_length);
+    return result;
+}
+
+
+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), nullptr, from_c(one_time_key_message), raw_length
+    );
+}
+
+
+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
+) {
+    std::uint8_t const * id_key = from_c(their_identity_key);
+    std::size_t id_key_length = their_identity_key_length;
+
+    if (olm::decode_base64_length(id_key_length) != CURVE25519_KEY_LENGTH) {
+        from_c(session)->last_error = OlmErrorCode::OLM_INVALID_BASE64;
+        return std::size_t(-1);
+    }
+    _olm_curve25519_public_key identity_key;
+    olm::decode_base64(id_key, id_key_length, identity_key.public_key);
+
+    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), &identity_key,
+        from_c(one_time_key_message), raw_length
+    );
+}
+
+
+size_t olm_session_id_length(
+    OlmSession const * session
+) {
+    return b64_output_length(from_c(session)->session_id_length());
+}
+
+size_t olm_session_id(
+    OlmSession * session,
+    void * id, size_t id_length
+) {
+    std::size_t raw_length = from_c(session)->session_id_length();
+    if (id_length < b64_output_length(raw_length)) {
+        from_c(session)->last_error =
+                OlmErrorCode::OLM_OUTPUT_BUFFER_TOO_SMALL;
+        return std::size_t(-1);
+    }
+    std::size_t result = from_c(session)->session_id(
+       b64_output_pos(from_c(id), raw_length), raw_length
+    );
+    if (result == std::size_t(-1)) {
+        return result;
+    }
+    return b64_output(from_c(id), raw_length);
+}
+
+
+int olm_session_has_received_message(
+    OlmSession const * session
+) {
+    return from_c(session)->received_message;
+}
+
+void olm_session_describe(
+    OlmSession * session, char *buf, size_t buflen
+) {
+    from_c(session)->describe(buf, buflen);
+}
+
+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(
+        nullptr, from_c(one_time_key_message), raw_length
+    );
+    return matches ? 1 : 0;
+}
+
+
+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
+) {
+    std::uint8_t const * id_key = from_c(their_identity_key);
+    std::size_t id_key_length = their_identity_key_length;
+
+    if (olm::decode_base64_length(id_key_length) != CURVE25519_KEY_LENGTH) {
+        from_c(session)->last_error = OlmErrorCode::OLM_INVALID_BASE64;
+        return std::size_t(-1);
+    }
+    _olm_curve25519_public_key identity_key;
+    olm::decode_base64(id_key, id_key_length, identity_key.public_key);
+
+    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(
+        &identity_key, 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
+    );
+    if (result == std::size_t(-1)) {
+        from_c(account)->last_error = OlmErrorCode::OLM_BAD_MESSAGE_KEY_ID;
+    }
+    return result;
+}
+
+
+size_t olm_encrypt_message_type(
+    OlmSession const * session
+) {
+    return size_t(from_c(session)->encrypt_message_type());
+}
+
+
+size_t olm_encrypt_random_length(
+    OlmSession const * session
+) {
+    return from_c(session)->encrypt_random_length();
+}
+
+
+size_t olm_encrypt_message_length(
+    OlmSession const * 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 * 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 < b64_output_length(raw_length)) {
+        from_c(session)->last_error =
+            OlmErrorCode::OLM_OUTPUT_BUFFER_TOO_SMALL;
+        return std::size_t(-1);
+    }
+    std::size_t result = from_c(session)->encrypt(
+        from_c(plaintext), plaintext_length,
+        from_c(random), random_length,
+        b64_output_pos(from_c(message), raw_length), raw_length
+    );
+    olm::unset(random, random_length);
+    if (result == std::size_t(-1)) {
+        return result;
+    }
+    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
+    );
+}
+
+
+size_t olm_sha256_length(
+   OlmUtility const * utility
+) {
+    return b64_output_length(from_c(utility)->sha256_length());
+}
+
+
+size_t olm_sha256(
+    OlmUtility * utility,
+    void const * input, size_t input_length,
+    void * output, size_t output_length
+) {
+    std::size_t raw_length = from_c(utility)->sha256_length();
+    if (output_length < b64_output_length(raw_length)) {
+        from_c(utility)->last_error =
+            OlmErrorCode::OLM_OUTPUT_BUFFER_TOO_SMALL;
+        return std::size_t(-1);
+    }
+    std::size_t result = from_c(utility)->sha256(
+       from_c(input), input_length,
+       b64_output_pos(from_c(output), raw_length), raw_length
+    );
+    if (result == std::size_t(-1)) {
+        return result;
+    }
+    return b64_output(from_c(output), raw_length);
+}
+
+
+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
+) {
+    if (olm::decode_base64_length(key_length) != CURVE25519_KEY_LENGTH) {
+        from_c(utility)->last_error = OlmErrorCode::OLM_INVALID_BASE64;
+        return std::size_t(-1);
+    }
+    _olm_ed25519_public_key verify_key;
+    olm::decode_base64(from_c(key), key_length, verify_key.public_key);
+    std::size_t raw_signature_length = b64_input(
+        from_c(signature), signature_length, from_c(utility)->last_error
+    );
+    if (raw_signature_length == std::size_t(-1)) {
+        return std::size_t(-1);
+    }
+    return from_c(utility)->ed25519_verify(
+        verify_key,
+        from_c(message), message_length,
+        from_c(signature), raw_signature_length
+    );
+}
+
+}