remove newline

[matrix_esp_thesis] / src / matrix.c

diff --git a/src/matrix.c b/src/matrix.c
index 90132af5f8a9b81c8a3dc755b6d5b1a12c7d63cd..8b186caa945e27cf1f18889d8c296d6d9b4b8e95 100644 (file)
--- a/src/matrix.c
+++ b/src/matrix.c
@@ -1,81 +1,1988 @@
 #include "matrix.h"\r
 \r
 #include "matrix.h"\r
 \r

+#include <time.h>\r
+#include <stdio.h>\r

 #include <mjson.h>\r
 #include <mjson.h>\r

+#include <olm/sas.h>\r

 \r
 \r

+#ifdef ESP_PLATFORM\r
+#include <esp_random.h>\r
+#endif\r

 \r
 \r

+// can be used to disable static allocation\r
+#define STATIC static\r
+\r
+// DEFINES\r

 #define LOGIN_REQUEST_SIZE 1024\r
 #define LOGIN_RESPONSE_SIZE 1024\r
 #define LOGIN_URL "/_matrix/client/v3/login"\r
 \r
 #define LOGIN_REQUEST_SIZE 1024\r
 #define LOGIN_RESPONSE_SIZE 1024\r
 #define LOGIN_URL "/_matrix/client/v3/login"\r
 \r

+#define ENCRYPTED_REQUEST_SIZE (1024*5)\r
+STATIC char g_EncryptedRequestBuffer[ENCRYPTED_REQUEST_SIZE];\r
+#define ENCRYPTED_EVENT_SIZE (1024*10)\r
+STATIC char g_EncryptedEventBuffer[ENCRYPTED_EVENT_SIZE];\r
+#define ROOM_SEND_REQUEST_SIZE 256\r
+#define ROOM_SEND_RESPONSE_SIZE 1024\r
+#define ROOM_SEND_URL "/_matrix/client/v3/rooms/%s/send/%s/%d"\r
+\r
+#define ROOMKEY_REQUEST_SIZE (1024*4)\r
+\r
+#define TODEVICE_EVENT_SIZE (1024*5)\r
+STATIC char g_TodeviceEventBuffer[TODEVICE_EVENT_SIZE];\r
+#define TODEVICE_URL "/_matrix/client/v3/sendToDevice/%s/%d"\r
+\r
+#define KEYS_QUERY_URL "/_matrix/client/v3/keys/query"\r
+#define KEYS_QUERY_REQUEST_SIZE 256\r
+#define KEYS_QUERY_RESPONSE_SIZE (1024*5)\r
+\r
+#define KEYS_UPLOAD_URL "/_matrix/client/v3/keys/upload"\r
+#define KEYS_UPLOAD_REQUEST_SIZE 1024*4\r
+STATIC char g_KeysUploadRequestBuffer[KEYS_UPLOAD_REQUEST_SIZE];\r
+#define KEYS_UPLOAD_REQUEST_SIGNED_SIZE 2048*4\r
+STATIC char g_KeysUploadRequestSignedBuffer[KEYS_UPLOAD_REQUEST_SIGNED_SIZE];\r
+#define KEYS_UPLOAD_RESPONSE_SIZE 2048\r
+\r
+#define KEYS_CLAIM_URL "/_matrix/client/v3/keys/claim"\r
+#define KEYS_CLAIM_REQUEST_SIZE 1024\r
+#define KEYS_CLAIM_RESPONSE_SIZE 1024\r
+\r
+#define SYNC_TIMEOUT 5000\r
+\r
+#define JSON_QUERY_SIZE 128\r
+#define JSON_MAX_INDICES 100\r
+#define JSON_MAX_ENTRY_SIZE 1024\r
+\r
+#define MAX(a,b) ((a) > (b) ? (a) : (b))\r
+#define MIN(a,b) ((a) < (b) ? (a) : (b))\r
+\r
+// Util\r
+\r
+void\r
+Randomize(\r
+    uint8_t * random,\r
+    int randomLen)\r
+{\r
+    #ifdef ESP_PLATFORM\r
+\r
+    for (int i = 0; i < randomLen; i++)\r
+    {\r
+        random[i] = esp_random() % 256;\r
+    }\r
+\r
+    #else\r
+\r
+    STATIC bool first = true;\r
+    if (first) { srand(time(0)); first = false; }\r
+\r
+    for (int i = 0; i < randomLen; i++)\r
+    {\r
+        random[i] = rand() % 256;\r
+    }\r
+\r
+    #endif\r
+}\r
+\r
+bool\r
+JsonEscape(\r
+    const char * sIn, int sInLen,\r
+    char * sOut, int sOutCap)\r
+{\r
+    int sOutIndex = 0;\r
+\r
+    for (int i = 0; i < sInLen; i++)\r
+    {\r
+        if (i >= sOutCap)\r
+            return false;\r
+        \r
+        if (sIn[i] == '.' ||\r
+            sIn[i] == '[' ||\r
+            sIn[i] == ']'\r
+        ) {\r
+            sOut[sOutIndex++] = '\\';\r
+        }\r
+        sOut[sOutIndex++] = sIn[i];\r
+    }\r
+\r
+    if (sOutIndex < sOutCap)\r
+        sOut[sOutIndex] = '\0';\r
+\r
+    return true;\r
+}\r
+\r
+bool\r
+JsonCanonicalize(\r
+    const char * sIn, int sInLen,\r
+    char * sOut, int sOutCap)\r
+{\r
+    snprintf(sOut, sOutCap, "{}");\r
+\r
+    int koff, klen, voff, vlen, vtype, off;\r
+\r
+    struct Key {\r
+        const char * ptr;\r
+        int len;\r
+    };\r
+\r
+    struct Key keys[JSON_MAX_INDICES];\r
+    int numKeys = 0;\r
+\r
+    for (off = 0; (off = mjson_next(sIn, sInLen, off, &koff, &klen, &voff, &vlen, &vtype)) != 0; ) {\r
+        keys[numKeys].ptr = sIn + koff;\r
+        keys[numKeys].len = klen;\r
+        numKeys++;\r
+    }\r
+\r
+    for (int i = 0; i < numKeys; i++) {\r
+        for (int j = i; j < numKeys; j++) {\r
+            if (\r
+                strncmp(\r
+                    keys[i].ptr,\r
+                    keys[j].ptr,\r
+                    MIN(keys[i].len, keys[j].len)\r
+                ) > 0\r
+            ) {\r
+                struct Key k = keys[i];\r
+                keys[i] = keys[j];\r
+                keys[j] = k;\r
+            }\r
+        }\r
+    }\r
+\r
+    for (int i = 0; i < numKeys; i++) {\r
+        char jp[JSON_QUERY_SIZE];\r
+        snprintf(jp, JSON_QUERY_SIZE, "$.%.*s", keys[i].len-2, keys[i].ptr+1);\r
+\r
+        const char * valPtr;\r
+        int valLen;\r
+        mjson_find(sIn, sInLen, jp, &valPtr, &valLen);\r
+        \r
+        STATIC char newEntry[JSON_MAX_ENTRY_SIZE];\r
+        snprintf(newEntry, JSON_MAX_ENTRY_SIZE, "{%.*s:%.*s}", keys[i].len, keys[i].ptr, valLen, valPtr);\r
+\r
+        char * buffer = strdup(sOut);\r
+\r
+        struct mjson_fixedbuf fb = { sOut, sOutCap, 0 };\r
+        mjson_merge(buffer, strlen(buffer), newEntry, strlen(newEntry), mjson_print_fixed_buf, &fb);\r
+\r
+        free(buffer);\r
+    }\r
+\r
+    // TODO: recursively sort entries\r
+\r
+    return true;\r
+}\r
+\r
+bool JsonSign(\r
+    MatrixClient * client,\r
+    const char * sIn, int sInLen,\r
+    char * sOut, int sOutCap)\r
+{\r
+    STATIC char signature[OLM_SIGNATURE_SIZE];\r
+    size_t res =\r
+        olm_account_sign(client->olmAccount.account,\r
+            sIn, sInLen,\r
+            signature, OLM_SIGNATURE_SIZE);\r
+    \r
+    int signatureLen = res;\r
+    \r
+    STATIC char thisSigningKey[SIGNING_KEY_SIZE];\r
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, SIGNING_KEY_SIZE);\r
+\r
+    STATIC char signatureJson[JSON_SIGNATURE_SIZE];\r
+    int signatureJsonLen =\r
+        mjson_snprintf(signatureJson, JSON_SIGNATURE_SIZE,\r
+            "{"\r
+                "\"signatures\":{"\r
+                    "\"%s\":{"\r
+                        "\"ed25519:%s\":\"%.*s\""\r
+                    "}"\r
+                "}"\r
+            "}",\r
+            client->userId,\r
+            //"1",\r
+            client->deviceId,\r
+            signatureLen, signature);\r
+\r
+    struct mjson_fixedbuf result = { sOut, sOutCap, 0 };\r
+    mjson_merge(\r
+        sIn, sInLen,\r
+        signatureJson, signatureJsonLen,\r
+        mjson_print_fixed_buf,\r
+        &result);\r
+\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixOlmAccountInit(\r
+    MatrixOlmAccount * account)\r
+{\r
+    account->account = olm_account(account->memory);\r
+\r
+    STATIC uint8_t random[OLM_ACCOUNT_RANDOM_SIZE];\r
+    Randomize(random, OLM_ACCOUNT_RANDOM_SIZE);\r
+\r
+    size_t res = olm_create_account(\r
+        account->account,\r
+        random,\r
+        OLM_ACCOUNT_RANDOM_SIZE);\r
+\r
+    return res != olm_error();\r
+}\r
+\r
+bool\r
+MatrixOlmAccountUnpickle(\r
+    MatrixOlmAccount * account,\r
+    void * pickled, int pickledLen,\r
+    const void * key, int keyLen)\r
+{\r
+    size_t res;\r
+    res = olm_unpickle_account(account->account,\r
+        key, keyLen,\r
+        pickled, pickledLen);\r
+    if (res == olm_error()) {\r
+        printf("error unpickling olm account:%s\n",\r
+            olm_account_last_error(account->account));\r
+    }\r
+    return res != olm_error();\r
+}\r
+\r
+bool\r
+MatrixOlmAccountGetDeviceKey(\r
+    MatrixOlmAccount * account,\r
+    char * key, int keyCap)\r
+{\r
+    STATIC char deviceKeysJson[OLM_IDENTITY_KEYS_JSON_SIZE];\r
+    size_t res =\r
+        olm_account_identity_keys(account->account,\r
+            deviceKeysJson, OLM_IDENTITY_KEYS_JSON_SIZE);\r
+    mjson_get_string(deviceKeysJson, res,\r
+        "$.curve25519",\r
+        key, keyCap);\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixOlmAccountGetSigningKey(\r
+    MatrixOlmAccount * account,\r
+    char * key, int keyCap)\r
+{\r
+    STATIC char deviceKeysJson[OLM_IDENTITY_KEYS_JSON_SIZE];\r
+    size_t res =\r
+        olm_account_identity_keys(account->account,\r
+            deviceKeysJson, OLM_IDENTITY_KEYS_JSON_SIZE);\r
+    mjson_get_string(deviceKeysJson, res,\r
+        "$.ed25519",\r
+        key, keyCap);\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixOlmSessionFrom(\r
+    MatrixOlmSession * session,\r
+    OlmAccount * olmAccount,\r
+    const char * deviceId,\r
+    const char * deviceKey,\r
+    const char * encrypted)\r
+{\r
+    memset(session, 0, sizeof(MatrixOlmSession));\r
+\r
+    session->deviceId = deviceId;\r
+\r
+    session->session =\r
+        olm_session(session->memory);\r
+    \r
+    char * encryptedCopy = strdup(encrypted);\r
+    \r
+    size_t res =\r
+        olm_create_inbound_session_from(session->session, olmAccount,\r
+            deviceKey, strlen(deviceKey),\r
+            encryptedCopy, strlen(encryptedCopy));\r
+    \r
+    if (res == olm_error()) {\r
+        printf("error olm:%s\n", olm_session_last_error(session->session));\r
+    }\r
+\r
+    return res != olm_error();\r
+}\r
+\r
+bool\r
+MatrixOlmSessionTo(\r
+    MatrixOlmSession * session,\r
+    OlmAccount * olmAccount,\r
+    const char * deviceId,\r
+    const char * deviceKey,\r
+    const char * deviceOnetimeKey)\r
+{\r
+    memset(session, 0, sizeof(MatrixOlmSession));\r
+\r
+    session->deviceId = deviceId;\r
+\r
+    session->session =\r
+        olm_session(session->memory);\r
+\r
+    STATIC uint8_t random[OLM_OUTBOUND_SESSION_RANDOM_SIZE];\r
+    Randomize(random, OLM_OUTBOUND_SESSION_RANDOM_SIZE);\r
+\r
+    size_t res =\r
+        olm_create_outbound_session(session->session,\r
+            olmAccount,\r
+            deviceKey, strlen(deviceKey),\r
+            deviceOnetimeKey, strlen(deviceOnetimeKey),\r
+            random, OLM_OUTBOUND_SESSION_RANDOM_SIZE);\r
+    \r
+    if (res == olm_error()) {\r
+        printf("error olm:%s\n", olm_session_last_error(session->session));\r
+    }\r
+\r
+    return res != olm_error();\r
+}\r
+\r
+bool\r
+MatrixOlmSessionUnpickle(\r
+    MatrixOlmSession * session,\r
+    const char * deviceId,\r
+    void * pickled, int pickledLen,\r
+    const void * key, int keyLen)\r
+{\r
+    memset(session, 0, sizeof(MatrixOlmSession));\r
+\r
+    session->deviceId = deviceId;\r
+\r
+    session->session =\r
+        olm_session(session->memory);\r
+    \r
+    size_t res;\r
+    res = olm_unpickle_session(session->session,\r
+        key, keyLen,\r
+        pickled, pickledLen);\r
+    \r
+    if (res == olm_error()) {\r
+        printf("error unpickling olm session:%s\n", olm_session_last_error(session->session));\r
+    }\r
+\r
+    return res != olm_error();\r
+}\r
+\r
+bool\r
+MatrixOlmSessionEncrypt(\r
+    MatrixOlmSession * session,\r
+    const char * plaintext,\r
+    char * outBuffer, int outBufferCap)\r
+{\r
+    STATIC uint8_t random[OLM_ENCRYPT_RANDOM_SIZE];\r
+    Randomize(random, OLM_ENCRYPT_RANDOM_SIZE);\r
+\r
+    memset(outBuffer, 0, outBufferCap);\r
+    size_t res = olm_encrypt(session->session,\r
+        plaintext, strlen(plaintext),\r
+        random, OLM_ENCRYPT_RANDOM_SIZE,\r
+        outBuffer, outBufferCap);\r
+\r
+    return res != olm_error();\r
+}\r
+\r
+bool\r
+MatrixOlmSessionDecrypt(\r
+    MatrixOlmSession * session,\r
+    size_t messageType,\r
+    char * encrypted,\r
+    char * outBuffer, int outBufferCap)\r
+{\r
+    STATIC uint8_t random[OLM_ENCRYPT_RANDOM_SIZE];\r
+    Randomize(random, OLM_ENCRYPT_RANDOM_SIZE);\r
+\r
+    size_t res =\r
+        olm_decrypt(session->session,\r
+            messageType,\r
+            encrypted, strlen(encrypted),\r
+            outBuffer, outBufferCap);\r
+    \r
+    if (res != olm_error() && (int)res < outBufferCap)\r
+        outBuffer[res] = '\0';\r
+\r
+    return res != olm_error();\r
+}\r
+\r
+bool\r
+MatrixMegolmInSessionInit(\r
+    MatrixMegolmInSession * session,\r
+    const char * roomId,\r
+    const char * sessionId,\r
+    const char * sessionKey, int sessionKeyLen)\r
+{\r
+    memset(session, 0, sizeof(MatrixMegolmInSession));\r
+    \r
+    strncpy(session->roomId, roomId, sizeof(session->roomId));\r
+    strncpy(session->id, sessionId, sizeof(session->id));\r
+    strncpy(session->key, sessionKey, sizeof(session->key));\r
+\r
+    session->session =\r
+        olm_inbound_group_session(session->memory);\r
+\r
+    size_t res =\r
+        olm_init_inbound_group_session(\r
+        // olm_import_inbound_group_session(\r
+            session->session,\r
+            (const uint8_t *)sessionKey, sessionKeyLen);\r
+    if (res == olm_error()) {\r
+        printf("Error initializing Megolm session: %s\n", olm_inbound_group_session_last_error(session->session));\r
+    }\r
+\r
+    return res != olm_error();\r
+}\r
+\r
+bool\r
+MatrixMegolmInSessionDecrypt(\r
+    MatrixMegolmInSession * session,\r
+    const char * encrypted, int encryptedLen,\r
+    char * outDecrypted, int outDecryptedCap)\r
+{\r
+    // uint8_t buffer[1024];\r
+    // memcpy(buffer, encrypted, encryptedLen);\r
+\r
+    uint32_t megolmInMessageIndex;\r
+\r
+    size_t res =\r
+        olm_group_decrypt(session->session,\r
+            (uint8_t *)encrypted, encryptedLen,\r
+            (uint8_t *)outDecrypted, outDecryptedCap,\r
+            &megolmInMessageIndex);\r
+    \r
+    if (res == olm_error()) {\r
+        printf("error decrypting megolm message: %s\n", olm_inbound_group_session_last_error(session->session));\r
+    }\r
+    \r
+    return true;\r
+}\r
+\r
+// https://matrix.org/docs/guides/end-to-end-encryption-implementation-guide#starting-a-megolm-session\r
+bool\r
+MatrixMegolmOutSessionInit(\r
+    MatrixMegolmOutSession * session,\r
+    const char * roomId)\r
+{\r
+    memset(session, 0, sizeof(MatrixMegolmOutSession));\r
+\r
+    STATIC uint8_t random[MEGOLM_INIT_RANDOM_SIZE];\r
+    Randomize(random, MEGOLM_INIT_RANDOM_SIZE);\r
+\r
+    strncpy(session->roomId, roomId, ROOM_ID_SIZE);\r
+\r
+    session->session =\r
+        olm_outbound_group_session(session->memory);\r
+\r
+    olm_init_outbound_group_session(\r
+        session->session,\r
+        random,\r
+        MEGOLM_INIT_RANDOM_SIZE);\r
+\r
+    olm_outbound_group_session_id(session->session,\r
+        (uint8_t *)session->id,\r
+        MEGOLM_SESSION_ID_SIZE);\r
+        \r
+    olm_outbound_group_session_key(session->session,\r
+        (uint8_t *)session->key,\r
+        MEGOLM_SESSION_KEY_SIZE);\r
+    \r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixMegolmOutSessionEncrypt(\r
+    MatrixMegolmOutSession * session,\r
+    const char * plaintext,\r
+    char * outBuffer, int outBufferCap)\r
+{\r
+    memset(outBuffer, 0, outBufferCap);\r
+    size_t res = olm_group_encrypt(session->session,\r
+        (uint8_t *)plaintext, strlen(plaintext),\r
+        (uint8_t *)outBuffer, outBufferCap);\r
+\r
+    return res != olm_error();\r
+}\r
+\r

 \r
 bool\r
 MatrixClientInit(\r
 \r
 bool\r
 MatrixClientInit(\r

+    MatrixClient * client)\r
+{\r
+    memset(client, 0, sizeof(MatrixClient));\r
+\r
+    // init olm account\r
+    MatrixOlmAccountInit(&client->olmAccount);\r
+\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixClientSetAccessToken(\r

     MatrixClient * client,\r
     MatrixClient * client,\r

-    char * server, int serverLen\r
-) {\r
-    strcpy_s(\r
-        client->server,\r
-        SERVER_SIZE,\r
-        server\r
-    );\r
-    client->serverLen = serverLen;\r
+    const char * accessToken)\r
+{\r
+    for (int i = 0; i < ACCESS_TOKEN_SIZE-1; i++)\r
+        client->accessToken[i] = accessToken[i];\r
+    client->accessToken[ACCESS_TOKEN_SIZE-1] = '\0';\r

 \r
     return true;\r
 }\r
 \r
 \r
     return true;\r
 }\r
 \r

-// https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3login\r

 bool\r
 bool\r

-MatrixClientLoginPassword(\r
+MatrixClientSetDeviceId(\r

     MatrixClient * client,\r
     MatrixClient * client,\r

-    char * username, int usernameLen,\r
-    char * password, int passwordLen,\r
-    char * displayName, int displayNameLen\r
-) {\r
-    static char requestBuffer[LOGIN_REQUEST_SIZE];\r
+    const char * deviceId)\r
+{\r
+    for (int i = 0; i < DEVICE_ID_SIZE-1; i++)\r
+        client->deviceId[i] = deviceId[i];\r
+    client->deviceId[DEVICE_ID_SIZE-1] = '\0';\r
+\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixClientSetUserId(\r
+    MatrixClient * client,\r
+    const char * userId)\r
+{\r
+    for (int i = 0; i < USER_ID_SIZE-1; i++)\r
+        client->userId[i] = userId[i];\r
+    client->userId[USER_ID_SIZE-1] = '\0';\r
+\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixClientGenerateOnetimeKeys(\r
+    MatrixClient * client,\r
+    int numberOfKeys)\r
+{\r
+    STATIC uint8_t random[OLM_ONETIME_KEYS_RANDOM_SIZE];\r
+    Randomize(random, OLM_ONETIME_KEYS_RANDOM_SIZE);\r
+\r
+    size_t res =\r
+        olm_account_generate_one_time_keys(client->olmAccount.account,\r
+            numberOfKeys, random, OLM_ONETIME_KEYS_RANDOM_SIZE);\r
+\r
+    return res != olm_error();\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysupload\r
+bool\r
+MatrixClientUploadOnetimeKeys(\r
+    MatrixClient * client)\r
+{\r
+    mjson_snprintf(g_KeysUploadRequestBuffer, KEYS_UPLOAD_REQUEST_SIZE,\r
+        "{");\r
+\r
+    STATIC char onetimeKeysBuffer[1024];\r
+    olm_account_one_time_keys(client->olmAccount.account,\r
+        onetimeKeysBuffer, 1024);\r
+\r
+    // olm_account_one_time_keys returns a json object\r
+    // find curve25519 member\r
+    const char *keys;\r
+    int keysLen;\r
+    mjson_find(onetimeKeysBuffer, strlen(onetimeKeysBuffer), "$.curve25519", &keys, &keysLen);\r

 \r
 \r

-    int requestLen =\r
-        mjson_snprintf(requestBuffer, LOGIN_REQUEST_SIZE,\r
+    // iterate over onetime keys, create key object\r
+    // sign it and append to request\r
+    int koff, klen, voff, vlen, vtype, off = 0;\r
+    while ((off = mjson_next(keys, keysLen, off, &koff, &klen, &voff, &vlen, &vtype)) != 0) {\r
+        STATIC char keyJson[JSON_ONETIME_KEY_SIZE];\r
+        \r
+        int keyJsonLen =\r
+            snprintf(keyJson, JSON_ONETIME_KEY_SIZE,\r
+                "{\"key\":\"%.*s\"}",\r
+                vlen-2, keys + voff+1);\r
+\r
+        STATIC char keyJsonSigned[JSON_ONETIME_KEY_SIGNED_SIZE];\r
+\r
+        JsonSign(client,\r
+            keyJson, keyJsonLen,\r
+            keyJsonSigned, JSON_ONETIME_KEY_SIGNED_SIZE);\r
+        \r
+        mjson_snprintf(g_KeysUploadRequestBuffer+strlen(g_KeysUploadRequestBuffer), KEYS_UPLOAD_REQUEST_SIZE-strlen(g_KeysUploadRequestBuffer),\r
+            "\"signed_curve25519:%.*s\":%s,",\r
+            klen-2, keys + koff+1,\r
+            keyJsonSigned);\r
+    }\r
+\r
+    // delete last ',' since the loop always appends it\r
+    if (g_KeysUploadRequestBuffer[strlen(g_KeysUploadRequestBuffer)-1] == ',')\r
+        g_KeysUploadRequestBuffer[strlen(g_KeysUploadRequestBuffer)-1] = '\0';\r
+\r
+    mjson_snprintf(g_KeysUploadRequestBuffer+strlen(g_KeysUploadRequestBuffer), KEYS_UPLOAD_REQUEST_SIZE-strlen(g_KeysUploadRequestBuffer),\r
+        "}");\r
+\r
+    snprintf(g_KeysUploadRequestSignedBuffer, KEYS_UPLOAD_REQUEST_SIGNED_SIZE,\r
+    "{\"one_time_keys\":%s}", g_KeysUploadRequestBuffer);\r
+\r
+    STATIC char responseBuffer[KEYS_UPLOAD_RESPONSE_SIZE];\r
+    MatrixHttpPost(client->hc,\r
+        KEYS_UPLOAD_URL,\r
+        g_KeysUploadRequestSignedBuffer,\r
+        responseBuffer, KEYS_UPLOAD_RESPONSE_SIZE,\r
+        true);\r
+\r
+    return true;\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysupload\r
+bool\r
+MatrixClientUploadDeviceKeys(\r
+    MatrixClient * client)\r
+{\r
+    char thisDeviceKey[DEVICE_KEY_SIZE];\r
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);\r
+    char thisSigningKey[DEVICE_KEY_SIZE];\r
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, DEVICE_KEY_SIZE);\r
+\r
+    int deviceKeysBufferLen =\r
+        mjson_snprintf(g_KeysUploadRequestBuffer, KEYS_UPLOAD_REQUEST_SIZE,\r

             "{"\r
             "{"\r

-                "\"type\": \"m.login.password\","\r
-                "\"identifier\": {"\r
-                    "\"type\": \"m.id.user\","\r
-                    "\"user\": \"%.*s\""\r
+                "\"algorithms\":[\"m.olm.v1.curve25519-aes-sha2\",\"m.megolm.v1.aes-sha2\"],"\r
+                "\"device_id\":\"%s\","\r
+                "\"keys\":{"\r
+                    "\"curve25519:%s\":\"%s\","\r
+                    "\"ed25519:%s\":\"%s\""\r

                 "},"\r
                 "},"\r

-                "\"password\": \"%.*s\","\r
-                "\"initial_device_display_name\": \"%.*s\""\r
+                "\"user_id\":\"%s\""\r

             "}",\r
             "}",\r

-            usernameLen, username,\r
-            passwordLen, password,\r
-            displayNameLen, displayName);\r
+            client->deviceId,\r
+            client->deviceId, thisDeviceKey,\r
+            client->deviceId, thisSigningKey,\r
+            client->userId);\r
+\r
+    JsonSign(client,\r
+        g_KeysUploadRequestBuffer, deviceKeysBufferLen,\r
+        g_KeysUploadRequestSignedBuffer, KEYS_UPLOAD_REQUEST_SIZE);\r
+    \r
+    STATIC char finalEvent[KEYS_UPLOAD_REQUEST_SIGNED_SIZE+30];\r
+    snprintf(finalEvent, KEYS_UPLOAD_REQUEST_SIGNED_SIZE+30,\r
+    "{\"device_keys\":%s}", g_KeysUploadRequestSignedBuffer);\r
+\r
+    STATIC char responseBuffer[KEYS_UPLOAD_RESPONSE_SIZE];\r
+    MatrixHttpPost(client->hc,\r
+        KEYS_UPLOAD_URL,\r
+        finalEvent,\r
+        responseBuffer, KEYS_UPLOAD_RESPONSE_SIZE,\r
+        true);\r
+\r
+    return true;\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysclaim\r
+bool\r
+MatrixClientClaimOnetimeKey(\r
+    MatrixClient * client,\r
+    const char * userId,\r
+    const char * deviceId,\r
+    char * outOnetimeKey, int outOnetimeKeyCap)\r
+{\r
+    STATIC char requestBuffer[KEYS_CLAIM_REQUEST_SIZE];\r
+    mjson_snprintf(requestBuffer, KEYS_CLAIM_REQUEST_SIZE,\r
+    "{"\r
+      "\"one_time_keys\":{"\r
+        "\"%s\":{"\r
+          "\"%s\":\"signed_curve25519\""\r
+        "}"\r
+      "},"\r
+      "\"timeout\":10000"\r
+    "}",\r
+    userId,\r
+    deviceId);\r
+\r
+    STATIC char responseBuffer[KEYS_CLAIM_RESPONSE_SIZE];\r
+    MatrixHttpPost(client->hc,\r
+        KEYS_CLAIM_URL,\r
+        requestBuffer,\r
+        responseBuffer, KEYS_CLAIM_RESPONSE_SIZE,\r
+        true);\r
+    \r
+    STATIC char userIdEscaped[USER_ID_SIZE];\r
+    JsonEscape(userId, strlen(userId),\r
+        userIdEscaped, USER_ID_SIZE);\r
+    \r
+    // create the json query according to\r
+    // https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysclaim\r
+    STATIC char query[JSON_QUERY_SIZE];\r
+    snprintf(query, JSON_QUERY_SIZE,\r
+        "$.one_time_keys.%s.%s",\r
+        userIdEscaped,\r
+        deviceId);\r
+    \r
+    // find the corresponding json object\r
+    const char * keyObject;\r
+    int keyObjectSize;\r
+    mjson_find(responseBuffer, strlen(responseBuffer),\r
+        query,\r
+        &keyObject, &keyObjectSize);\r
+    \r
+    // use mjson_next (which iterates over all key/value pairs) once\r
+    // because we only request one key\r
+    // (see https://github.com/cesanta/mjson#mjson_next for details)\r
+    int koff, klen, voff, vlen, vtype;\r
+    mjson_next(keyObject, keyObjectSize, 0,\r
+        &koff, &klen, &voff, &vlen, &vtype);\r
+    \r
+    mjson_get_string(keyObject + voff, vlen,\r
+        "$.key", outOnetimeKey, outOnetimeKeyCap);\r

     \r
     \r

-    static char responseBuffer[LOGIN_RESPONSE_SIZE];\r
-    int responseLen;\r
+    // TODO: verify signature\r
+    \r
+    return true;\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3login\r
+bool\r
+MatrixClientLoginPassword(\r
+    MatrixClient * client,\r
+    const char * username,\r
+    const char * password,\r
+    const char * displayName)\r
+{\r
+    STATIC char requestBuffer[LOGIN_REQUEST_SIZE];\r
+\r
+    mjson_snprintf(requestBuffer, LOGIN_REQUEST_SIZE,\r
+        "{"\r
+            "\"type\":\"m.login.password\","\r
+            "\"identifier\":{"\r
+                "\"type\":\"m.id.user\","\r
+                "\"user\":\"%s\""\r
+            "},"\r
+            "\"password\":\"%s\","\r
+            "\"initial_device_display_name\":\"%s\""\r
+        "}",\r
+        username,\r
+        password,\r
+        displayName);\r
+    \r
+    STATIC char responseBuffer[LOGIN_RESPONSE_SIZE];\r

     bool result =\r
     bool result =\r

-        MatrixHttpPost(client,\r
+        MatrixHttpPost(client->hc,\r

             LOGIN_URL,\r
             LOGIN_URL,\r

-            requestBuffer, requestLen,\r
-            responseBuffer, LOGIN_RESPONSE_SIZE, &responseLen);\r
+            requestBuffer,\r
+            responseBuffer, LOGIN_RESPONSE_SIZE,\r
+            false);\r

     \r
     if (!result)\r
         return false;\r
     \r
     if (!result)\r
         return false;\r

+    \r
+    int responseLen = strlen(responseBuffer);\r

 \r
 \r

-    client->accessTokenLen =\r
-        mjson_get_string(responseBuffer, responseLen,\r
-            "$.access_token",\r
-            client->accessTokenBuffer, ACCESS_TOKEN_SIZE);\r
-    client->deviceIdLen =\r
-        mjson_get_string(responseBuffer, responseLen,\r
-            "$.device_id",\r
-            client->deviceIdBuffer, DEVICE_ID_SIZE);\r
-    client->expireMsLen =\r
-        mjson_get_string(responseBuffer, responseLen,\r
-            "$.expires_in_ms",\r
-            client->expireMsBuffer, EXPIRE_MS_SIZE);\r
-    client->refreshTokenLen =\r
-        mjson_get_string(responseBuffer, responseLen,\r
-            "$.refresh_token",\r
-            client->refreshTokenBuffer, REFRESH_TOKEN_SIZE);\r
+    // store variables in MatrixClient\r
+    mjson_get_string(responseBuffer, responseLen,\r
+        "$.access_token",\r
+        client->accessToken, ACCESS_TOKEN_SIZE);\r
+    mjson_get_string(responseBuffer, responseLen,\r
+        "$.device_id",\r
+        client->deviceId, DEVICE_ID_SIZE);\r
+    mjson_get_string(responseBuffer, responseLen,\r
+        "$.expires_in_ms",\r
+        client->expireMs, EXPIRE_MS_SIZE);\r
+    mjson_get_string(responseBuffer, responseLen,\r
+        "$.refresh_token",\r
+        client->refreshToken, REFRESH_TOKEN_SIZE);\r
+        \r
+    MatrixHttpSetAccessToken(client->hc, client->accessToken);\r

 \r
     return true;\r
 }\r
 \r
 \r
     return true;\r
 }\r
 \r

+// https://spec.matrix.org/v1.8/client-server-api/#put_matrixclientv3roomsroomidsendeventtypetxnid\r
+bool\r
+MatrixClientSendEvent(\r
+    MatrixClient * client,\r
+    const char * roomId,\r
+    const char * msgType,\r
+    const char * msgBody)\r
+{    \r
+    STATIC char requestUrl[MAX_URL_LEN];\r
+    snprintf(requestUrl, MAX_URL_LEN,\r
+        ROOM_SEND_URL, roomId, msgType, (int)time(NULL));\r
+\r
+    STATIC char responseBuffer[ROOM_SEND_RESPONSE_SIZE];\r
+    bool result =\r
+        MatrixHttpPut(client->hc,\r
+            requestUrl,\r
+            msgBody,\r
+            responseBuffer, ROOM_SEND_RESPONSE_SIZE,\r
+            true);\r
+    \r
+    return result;\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#mroomencrypted\r
+// https://matrix.org/docs/guides/end-to-end-encryption-implementation-guide#sending-an-encrypted-message-event\r
+bool\r
+MatrixClientSendEventEncrypted(\r
+    MatrixClient * client,\r
+    const char * roomId,\r
+    const char * msgType,\r
+    const char * msgBody)\r
+{\r
+    // event json\r
+    STATIC char requestBuffer[ROOM_SEND_REQUEST_SIZE];\r
+    snprintf(requestBuffer, ROOM_SEND_REQUEST_SIZE,\r
+        "{"\r
+        "\"type\":\"%s\","\r
+        "\"content\":%s,"\r
+        "\"room_id\":\"%s\""\r
+        "}",\r
+        msgType,\r
+        msgBody,\r
+        roomId);\r
+\r
+    // get megolm session\r
+    MatrixMegolmOutSession * outSession;\r
+    if (! MatrixClientGetMegolmOutSession(client, roomId, &outSession))\r
+        MatrixClientNewMegolmOutSession(client, roomId, &outSession);\r
+        \r
+    // encrypt\r
+    MatrixMegolmOutSessionEncrypt(outSession,\r
+        requestBuffer,\r
+        g_EncryptedRequestBuffer, ENCRYPTED_REQUEST_SIZE);\r
+\r
+    char thisDeviceKey[DEVICE_KEY_SIZE];\r
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);\r
+    \r
+\r
+    // encrypted event json\r
+    const char * senderKey = thisDeviceKey;\r
+    const char * sessionId = outSession->id;\r
+    const char * deviceId = client->deviceId;\r
+\r
+    snprintf(g_EncryptedEventBuffer, ENCRYPTED_EVENT_SIZE,\r
+        "{"\r
+        "\"algorithm\":\"m.megolm.v1.aes-sha2\","\r
+        "\"ciphertext\":\"%s\","\r
+        "\"device_id\":\"%s\","\r
+        "\"sender_key\":\"%s\","\r
+        "\"session_id\":\"%s\""\r
+        "}",\r
+        g_EncryptedRequestBuffer,\r
+        deviceId,\r
+        senderKey,\r
+        sessionId);\r
+\r
+    // send\r
+    return MatrixClientSendEvent(client,\r
+        roomId,\r
+        "m.room.encrypted",\r
+        g_EncryptedEventBuffer);\r
+}\r
+\r
+// this handles to_device events received from a sync\r
+// mainly for verification (m.key.verification.* events)\r
+void\r
+MatrixClientHandleEvent(\r
+    MatrixClient * client,\r
+    const char * event, int eventLen\r
+) {\r
+    // get the event type\r
+    STATIC char eventType[128];\r
+    memset(eventType, 0, sizeof(eventType));\r
+    mjson_get_string(event, eventLen, "$.type", eventType, 128);\r
+\r
+    // static variables for verification\r
+    // since verification takes multiple requests\r
+    // data is cleared when verification is finished or started\r
+    static char transactionId[64];\r
+    static char verifyFromDeviceId[DEVICE_ID_SIZE];\r
+    static OlmSAS * olmSas = NULL;\r
+\r
+    // initial verification request, reply that we are ready to verify\r
+    if (strcmp(eventType, "m.key.verification.request") == 0) {\r
+        // reset static data\r
+        memset(transactionId, 0, 64);\r
+        memset(verifyFromDeviceId, 0, DEVICE_ID_SIZE);\r
+        if (olmSas != NULL)\r
+            free(olmSas);\r
+        \r
+        mjson_get_string(event, eventLen, "$.content.transaction_id", transactionId, 64);\r
+        mjson_get_string(event, eventLen, "$.content.from_device", verifyFromDeviceId, DEVICE_ID_SIZE);\r
+        \r
+        char verificationReadyBuffer[2048];\r
+        snprintf(verificationReadyBuffer, 2048,\r
+            "{"\r
+            "\"from_device\":\"%s\","\r
+            "\"methods\":[\"m.sas.v1\"],"\r
+            "\"transaction_id\":\"%s\""\r
+            "}",\r
+            client->deviceId,\r
+            transactionId);\r
+        \r
+        MatrixClientSendToDevice(client,\r
+            client->userId,\r
+            verifyFromDeviceId,\r
+            verificationReadyBuffer,\r
+            "m.key.verification.ready");\r
+    }\r
+    else if (strcmp(eventType, "m.key.verification.start") == 0) {\r
+        olmSas = olm_sas(malloc(olm_sas_size()));\r
+        void * sasRandomBytes = malloc(olm_create_sas_random_length(olmSas));\r
+        olm_create_sas(olmSas,\r
+            sasRandomBytes,\r
+            olm_create_sas_random_length(olmSas));\r
+        \r
+        OlmUtility * olmUtil = olm_utility(malloc(olm_utility_size()));\r
+        \r
+        // calculate commitment according to \r
+        // https://spec.matrix.org/v1.8/client-server-api/#mkeyverificationaccept\r
+        STATIC char publicKey[64];\r
+        STATIC char keyStartJsonCanonical[512];\r
+        STATIC char concat[512+64];\r
+        STATIC char commitment[1024];\r
+        olm_sas_get_pubkey(olmSas,\r
+            publicKey,\r
+            64);\r
+\r
+        const char * keyStartJson;\r
+        int keyStartJsonLen;\r
+        mjson_find(event, eventLen, "$.content", &keyStartJson, &keyStartJsonLen);\r
+        JsonCanonicalize(keyStartJson, keyStartJsonLen, keyStartJsonCanonical, 512);\r
+\r
+        int concatLen =\r
+            snprintf(concat, 512+64, "%.*s%s", (int)olm_sas_pubkey_length(olmSas), publicKey, keyStartJsonCanonical);\r
+\r
+        int commitmentLen =\r
+            olm_sha256(olmUtil, concat, concatLen, commitment, 1024);\r
+        olm_clear_utility(olmUtil);\r
+        free(olmUtil);\r
+        \r
+        STATIC char verificationAcceptBuffer[512];\r
+        snprintf(verificationAcceptBuffer, 512,\r
+            "{"\r
+            "\"commitment\":\"%.*s\","\r
+            "\"hash\":\"sha256\","\r
+            "\"key_agreement_protocol\":\"curve25519\","\r
+            "\"message_authentication_code\":\"hkdf-hmac-sha256.v2\","\r
+            "\"method\":\"m.sas.v1\","\r
+            "\"short_authentication_string\":[\"decimal\"],"\r
+            "\"transaction_id\":\"%s\""\r
+            "}",\r
+            commitmentLen, commitment,\r
+            transactionId);\r
+        \r
+        MatrixClientSendToDevice(client,\r
+            client->userId,\r
+            verifyFromDeviceId,\r
+            verificationAcceptBuffer,\r
+            "m.key.verification.accept");\r
+    }\r
+    // send our sas key and calculate sas using their received key\r
+    else if (strcmp(eventType, "m.key.verification.key") == 0) {\r
+        STATIC char publicKey[128];\r
+        olm_sas_get_pubkey(olmSas,\r
+            publicKey,\r
+            128);\r
+\r
+        STATIC char theirPublicKey[128];\r
+        int theirPublicKeyLen =\r
+            mjson_get_string(event, eventLen, "$.content.key", theirPublicKey, 128);\r
+\r
+        olm_sas_set_their_key(olmSas, theirPublicKey, theirPublicKeyLen);\r
+        \r
+        STATIC char verificationKeyBuffer[256];\r
+        snprintf(verificationKeyBuffer, 256,\r
+            "{"\r
+            "\"key\":\"%.*s\","\r
+            "\"transaction_id\":\"%s\""\r
+            "}",\r
+            (int)olm_sas_pubkey_length(olmSas), publicKey,\r
+            transactionId);\r
+        \r
+        MatrixClientSendToDevice(client,\r
+            client->userId,\r
+            verifyFromDeviceId,\r
+            verificationKeyBuffer,\r
+            "m.key.verification.key");\r
+        \r
+        // sas\r
+        STATIC char hkdfInfo[1024];\r
+        int hkdfInfoLen =\r
+            snprintf(hkdfInfo, 1024,\r
+                "MATRIX_KEY_VERIFICATION_SAS%s%s%s%s%s",\r
+                client->userId,\r
+                verifyFromDeviceId,\r
+                client->userId,\r
+                client->deviceId,\r
+                transactionId);\r
+\r
+        unsigned char sasBytes[5];\r
+        olm_sas_generate_bytes(olmSas,\r
+            hkdfInfo, hkdfInfoLen,\r
+            sasBytes, 5);\r
+        int b0 = sasBytes[0];\r
+        int b1 = sasBytes[1];\r
+        int b2 = sasBytes[2];\r
+        int b3 = sasBytes[3];\r
+        int b4 = sasBytes[4];\r
+\r
+        // for now just printf SAS numbers\r
+        // https://spec.matrix.org/v1.8/client-server-api/#sas-method-decimal\r
+        printf("%d | %d | %d\n",\r
+            ((b0 << 5) | (b1 >> 3)) + 1000,\r
+            (((b1 & 0x7) << 10) | (b2 << 2) | (b3 >> 6)) + 1000,\r
+            (((b3 & 0x3F) << 7) | (b4 >> 1)) + 1000);\r
+    }\r
+    // calculate MACs for signing key, master key and the key list\r
+    else if (strcmp(eventType, "m.key.verification.mac") == 0) {        \r
+        // mac\r
+        STATIC char masterKey[123];\r
+        MatrixClientRequestMasterKey(client, masterKey, 123);\r
+\r
+        STATIC char keyList[256];\r
+        STATIC char keyListMac[256];\r
+        STATIC char key1Id[128];\r
+        STATIC char key1[128];\r
+        STATIC char key1Mac[128];\r
+        STATIC char key2Id[128];\r
+        STATIC char key2[128];\r
+        STATIC char key2Mac[128];\r
+\r
+        // keys have to be sorted so write keys/key IDs into key1/key2\r
+        // depending on lexicographical order\r
+        if (strcmp(masterKey, client->deviceId) < 0) {\r
+            snprintf(key1Id, 1024, "ed25519:%s", masterKey);\r
+            strcpy(key1, masterKey);\r
+            snprintf(key2Id, 1024, "ed25519:%s", client->deviceId);\r
+            MatrixOlmAccountGetSigningKey(&client->olmAccount, key2, 1024);\r
+        }\r
+        else {\r
+            snprintf(key1Id, 1024, "ed25519:%s", client->deviceId);\r
+            MatrixOlmAccountGetSigningKey(&client->olmAccount, key1, 1024);\r
+            snprintf(key2Id, 1024, "ed25519:%s", masterKey);\r
+            strcpy(key2, masterKey);\r
+        }\r
+\r
+        // create key list\r
+        snprintf(keyList, 1024,\r
+            "%s,%s", key1Id, key2Id);\r
+        \r
+        // generate MAC info for both keys and key list\r
+        // https://spec.matrix.org/v1.8/client-server-api/#mac-calculation\r
+        STATIC char macInfo[1024];\r
+        int macInfoLen;\r
+        {\r
+            macInfoLen =\r
+                snprintf(macInfo, 1024,\r
+                    "MATRIX_KEY_VERIFICATION_MAC%s%s%s%s%s%s",\r
+                    client->userId,\r
+                    client->deviceId,\r
+                    client->userId,\r
+                    verifyFromDeviceId,\r
+                    transactionId,\r
+                    "KEY_IDS");\r
+            olm_sas_calculate_mac_fixed_base64(olmSas, keyList, strlen(keyList), macInfo, macInfoLen, keyListMac, 1024);\r
+        }\r
+        {\r
+            macInfoLen =\r
+                snprintf(macInfo, 1024,\r
+                    "MATRIX_KEY_VERIFICATION_MAC%s%s%s%s%s%s",\r
+                    client->userId,\r
+                    client->deviceId,\r
+                    client->userId,\r
+                    verifyFromDeviceId,\r
+                    transactionId,\r
+                    key1Id);\r
+            olm_sas_calculate_mac_fixed_base64(olmSas, key1, strlen(key1), macInfo, macInfoLen, key1Mac, 1024);\r
+        }\r
+        {\r
+            macInfoLen =\r
+                snprintf(macInfo, 1024,\r
+                    "MATRIX_KEY_VERIFICATION_MAC%s%s%s%s%s%s",\r
+                    client->userId,\r
+                    client->deviceId,\r
+                    client->userId,\r
+                    verifyFromDeviceId,\r
+                    transactionId,\r
+                    key2Id);\r
+            olm_sas_calculate_mac_fixed_base64(olmSas, key2, strlen(key2), macInfo, macInfoLen, key2Mac, 1024);\r
+        }\r
+\r
+        // construct message and send\r
+        STATIC char verificationMacBuffer[1024];\r
+        snprintf(verificationMacBuffer, 1024,\r
+            "{"\r
+            "\"keys\":\"%s\","\r
+            "\"mac\":{"\r
+            "\"%s\":\"%s\","\r
+            "\"%s\":\"%s\""\r
+            "},"\r
+            "\"transaction_id\":\"%s\""\r
+            "}",\r
+            keyListMac,\r
+            key1Id,\r
+            key1Mac,\r
+            key2Id,\r
+            key2Mac,\r
+            transactionId);\r
+        \r
+        MatrixClientSendToDevice(client,\r
+            client->userId,\r
+            verifyFromDeviceId,\r
+            verificationMacBuffer,\r
+            "m.key.verification.mac");\r
+\r
+        // send 'done' message\r
+        STATIC char verificationDoneBuffer[128];\r
+        snprintf(verificationDoneBuffer, 128,\r
+            "{"\r
+            "\"transaction_id\":\"%s\""\r
+            "}",\r
+            transactionId);\r
+        \r
+        MatrixClientSendToDevice(client,\r
+            client->userId,\r
+            verifyFromDeviceId,\r
+            verificationDoneBuffer,\r
+            "m.key.verification.done");\r
+        \r
+        free(olmSas);\r
+\r
+        client->verified = true;\r
+    }\r
+    else if (strcmp(eventType, "m.room.encrypted") == 0) {\r
+        STATIC char algorithm[128];\r
+        mjson_get_string(event, eventLen, "$.content.algorithm", algorithm, 128);\r
+\r
+        // since this only handles to_device messages algorithm should always be olm\r
+        if (strcmp(algorithm, "m.olm.v1.curve25519-aes-sha2") == 0) {\r
+            STATIC char thisDeviceKey[DEVICE_KEY_SIZE];\r
+            MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);\r
+\r
+            STATIC char jp[128];\r
+            snprintf(jp, 128, "$.content.ciphertext.%s.type", thisDeviceKey);\r
+\r
+            double messageType;\r
+            mjson_get_number(event, eventLen, jp, &messageType);\r
+            int messageTypeInt = (int)messageType;\r
+\r
+            snprintf(jp, 128, "$.content.ciphertext.%s.body", thisDeviceKey);\r
+\r
+            mjson_get_string(event, eventLen, jp, g_EncryptedEventBuffer, 2048);\r
+\r
+            MatrixOlmSession * olmSession;\r
+            \r
+            // depending on message type create new incoming\r
+            // (type 0 indicates a new session so we dont check locally)\r
+            if (messageTypeInt == 0) {\r
+                MatrixClientNewOlmSessionIn(client,\r
+                    client->userId,\r
+                    verifyFromDeviceId,\r
+                    g_EncryptedEventBuffer,\r
+                    &olmSession);\r
+            }\r
+            // or new outgoing, checking for known sessions first\r
+            else {\r
+                if (! MatrixClientGetOlmSession(client, client->userId, verifyFromDeviceId, &olmSession))\r
+                {\r
+                    MatrixClientNewOlmSessionOut(client,\r
+                        client->userId,\r
+                        verifyFromDeviceId,\r
+                        &olmSession);\r
+                }\r
+            }\r
+            \r
+            STATIC char decrypted[2048];\r
+            MatrixOlmSessionDecrypt(olmSession,\r
+                messageTypeInt, g_EncryptedEventBuffer, decrypted, 2048);\r
+            \r
+            MatrixClientHandleEvent(client, decrypted, strlen(decrypted));\r
+        }\r
+    }\r
+    else if (strcmp(eventType, "m.room_key") == 0 ||\r
+             strcmp(eventType, "m.forwarded_room_key") == 0) {\r
+        // store session information\r
+        STATIC char roomId[128];\r
+        STATIC char sessionId[128];\r
+        STATIC char sessionKey[1024];\r
+        mjson_get_string(event, eventLen, "$.content.room_id", roomId, 128);\r
+        mjson_get_string(event, eventLen, "$.content.session_id", sessionId, 128);\r
+        mjson_get_string(event, eventLen, "$.content.session_key", sessionKey, 1024);\r
+\r
+        MatrixMegolmInSession * megolmInSession;\r
+        MatrixClientNewMegolmInSession(client, roomId, sessionId, sessionKey, &megolmInSession);\r
+    }\r
+}\r
+\r
+void\r
+MatrixClientHandleRoomEvent(\r
+    MatrixClient * client,\r
+    const char * room, int roomLen,\r
+    const char * event, int eventLen)\r
+{\r
+    STATIC char eventType[128];\r
+    memset(eventType, 0, sizeof(eventType));\r
+    mjson_get_string(event, eventLen, "$.type", eventType, 128);\r
+\r
+    if (strcmp(eventType, "m.room.encrypted") == 0) {\r
+        STATIC char algorithm[128];\r
+        mjson_get_string(event, eventLen, "$.content.algorithm", algorithm, 128);\r
+\r
+        // only room specific message type is encrypted\r
+        // since this is only room messages, algorithm should always be megolm\r
+        if (strcmp(algorithm, "m.megolm.v1.aes-sha2") == 0) {\r
+            STATIC char sessionId[128];\r
+            int sessionIdLen =\r
+                mjson_get_string(event, eventLen, "$.content.session_id", sessionId, 128);\r
+\r
+            bool res;\r
+\r
+            MatrixMegolmInSession * megolmInSession;\r
+            res = MatrixClientGetMegolmInSession(client,\r
+                room, roomLen,\r
+                sessionId, sessionIdLen,\r
+                &megolmInSession);\r
+\r
+            if (res) {\r
+                mjson_get_string(event, eventLen, "$.content.ciphertext", g_EncryptedEventBuffer, 2048);\r
+\r
+                STATIC char decrypted[2048];\r
+                MatrixMegolmInSessionDecrypt(megolmInSession, g_EncryptedEventBuffer, strlen(g_EncryptedEventBuffer), decrypted, 2048);\r
+\r
+                MatrixClientHandleEvent(client, decrypted, strlen(decrypted));\r
+            }\r
+            else {\r
+                printf("error: megolm session not known\n");\r
+            }\r
+        }\r
+    }\r
+    MatrixClientHandleEvent(client, event, eventLen);\r
+}\r
+\r
+// pass the response from sync to Handle(Room)Event\r
+void\r
+MatrixClientHandleSync(\r
+    MatrixClient * client,\r
+    char * syncBuffer, int syncBufferLen,\r
+    char * nextBatch, int nextBatchCap)\r
+{    \r
+    int res;\r
+\r
+    const char * s = syncBuffer;\r
+    int slen = syncBufferLen;\r
+\r
+    // read next_batch\r
+    mjson_get_string(s, slen, "$.next_batch", nextBatch, nextBatchCap);\r
+\r
+    // to_device\r
+    const char * events;\r
+    int eventsLen;\r
+    res =\r
+        mjson_find(s, slen, "$.to_device.events", &events, &eventsLen);\r
+    \r
+    // iterate event and pass to HandleEvent\r
+    if (res != MJSON_TOK_INVALID) {\r
+        {\r
+        int koff, klen, voff, vlen, vtype, off = 0;\r
+        for (off = 0; (off = mjson_next(events, eventsLen, off, &koff, &klen,\r
+                                        &voff, &vlen, &vtype)) != 0; ) {\r
+            const char * v = events + voff;\r
+\r
+            MatrixClientHandleEvent(client, v, vlen);\r
+        }\r
+        }\r
+    }\r
+\r
+    // rooms\r
+    const char * rooms;\r
+    int roomsLen;\r
+    res =\r
+        mjson_find(s, slen, "$.rooms.join", &rooms, &roomsLen);\r
+    \r
+    if (res != MJSON_TOK_INVALID) {\r
+        // iterate rooms\r
+        int koff, klen, voff, vlen, vtype, off = 0;\r
+        for (off = 0; (off = mjson_next(rooms, roomsLen, off, &koff, &klen,\r
+                                        &voff, &vlen, &vtype)) != 0; ) {\r
+            const char * k = rooms + koff;\r
+            const char * v = rooms + voff;\r
+\r
+            const char * events;\r
+            int eventsLen;\r
+            res =\r
+                mjson_find(v, vlen, "$.timeline.events", &events, &eventsLen);\r
+            \r
+            if (res != MJSON_TOK_INVALID) {\r
+                // iterate messages in that room\r
+                int koff2, klen2, voff2, vlen2, vtype2, off2 = 0;\r
+                for (off2 = 0; (off2 = mjson_next(events, eventsLen, off2, &koff2, &klen2,\r
+                                                &voff2, &vlen2, &vtype2)) != 0; ) {\r
+                    const char * v2 = events + voff2;\r
+\r
+                    MatrixClientHandleRoomEvent(client,\r
+                        k+1, klen-2,\r
+                        v2, vlen2);\r
+                }\r
+            }\r
+        }\r
+    }\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#get_matrixclientv3sync\r
+bool\r
+MatrixClientSync(\r
+    MatrixClient * client,\r
+    char * outSyncBuffer, int outSyncCap,\r
+    char * nextBatch, int nextBatchCap)\r
+{\r
+    // filter={\"event_fields\":[\"to_device\"]}\r
+    STATIC char url[MAX_URL_LEN];\r
+    snprintf(url, MAX_URL_LEN,\r
+        "/_matrix/client/v3/sync?timeout=%d" "%s" "%s",\r
+        SYNC_TIMEOUT,\r
+        "",\r
+        // "&filter={\"event_fields\":[\"to_device\"]}",\r
+        strlen(nextBatch) > 0 ? "&since=" : "");\r
+    \r
+    int index = strlen(url);\r
+\r
+    // URL encode next_batch parameter since it can include ~\r
+    for (size_t i = 0; i < strlen(nextBatch); i++) {\r
+        char c = nextBatch[i];\r
+\r
+        if (c == '~') {\r
+            url[index++] = '%';\r
+            url[index++] = '7';\r
+            url[index++] = 'E';\r
+        }\r
+        else {\r
+            url[index++] = c;\r
+        }\r
+    }\r
+    url[index] = '\0';\r
+\r
+    bool result =\r
+        MatrixHttpGet(client->hc,\r
+            url,\r
+            outSyncBuffer, outSyncCap,\r
+            true);\r
+    \r
+    MatrixClientHandleSync(client,\r
+        outSyncBuffer, strlen(outSyncBuffer),\r
+        nextBatch, nextBatchCap);\r
+    \r
+    return result;\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#get_matrixclientv3roomsroomideventeventid\r
+bool\r
+MatrixClientGetRoomEvent(\r
+    MatrixClient * client,\r
+    const char * roomId,\r
+    const char * eventId,\r
+    char * outEvent, int outEventCap)\r
+{\r
+    STATIC char url[MAX_URL_LEN];\r
+    snprintf(url, MAX_URL_LEN,\r
+        "/_matrix/client/v3/rooms/%s/event/%s",\r
+            roomId,\r
+            eventId);\r
+\r
+    return\r
+        MatrixHttpGet(client->hc,\r
+            url,\r
+            outEvent, outEventCap,\r
+            true);\r
+}\r
+\r
+bool\r
+MatrixClientShareMegolmOutSession(\r
+    MatrixClient * client,\r
+    const char * userId,\r
+    const char * deviceId,\r
+    MatrixMegolmOutSession * session)\r
+{\r
+    // generate room key event\r
+    STATIC char eventBuffer[KEY_SHARE_EVENT_LEN];\r
+    snprintf(eventBuffer, KEY_SHARE_EVENT_LEN,\r
+        "{"\r
+            "\"algorithm\":\"m.megolm.v1.aes-sha2\","\r
+            "\"room_id\":\"%s\","\r
+            "\"session_id\":\"%s\","\r
+            "\"session_key\":\"%s\""\r
+        "}",\r
+        session->roomId,\r
+        session->id,\r
+        session->key\r
+    );\r
+\r
+    // send\r
+    MatrixClientSendToDeviceEncrypted(client,\r
+        userId,\r
+        deviceId,\r
+        eventBuffer,\r
+        "m.room_key");\r
+\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixClientGetMegolmOutSession(\r
+    MatrixClient * client,\r
+    const char * roomId,\r
+    MatrixMegolmOutSession ** outSession)\r
+{\r
+    for (int i = 0; i < client->numMegolmOutSessions; i++)\r
+    {\r
+        if (strcmp(client->megolmOutSessions[i].roomId, roomId) == 0)\r
+        {\r
+            *outSession = &client->megolmOutSessions[i];\r
+            return true;\r
+        }\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientNewMegolmOutSession(\r
+    MatrixClient * client,\r
+    const char * roomId,\r
+    MatrixMegolmOutSession ** outSession)\r
+{\r
+    if (client->numMegolmOutSessions < NUM_MEGOLM_SESSIONS)\r
+    {\r
+        MatrixMegolmOutSession * result =\r
+            &client->megolmOutSessions[client->numMegolmOutSessions];\r
+        \r
+        MatrixMegolmOutSessionInit(result,\r
+            roomId);\r
+\r
+        *outSession = result;\r
+\r
+        client->numMegolmOutSessions++;\r
+\r
+        return true;\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientGetMegolmInSession(\r
+    MatrixClient * client,\r
+    const char * roomId, int roomIdLen,\r
+    const char * sessionId, int sessionIdLen,\r
+    MatrixMegolmInSession ** outSession)\r
+{\r
+    for (int i = 0; i < client->numMegolmInSessions; i++)\r
+    {\r
+        if (strncmp(client->megolmInSessions[i].roomId, roomId, roomIdLen) == 0 &&\r
+            strncmp(client->megolmInSessions[i].id, sessionId, sessionIdLen) == 0)\r
+        {\r
+            *outSession = &client->megolmInSessions[i];\r
+            return true;\r
+        }\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientNewMegolmInSession(\r
+    MatrixClient * client,\r
+    const char * roomId,\r
+    const char * sessionId,\r
+    const char * sessionKey,\r
+    MatrixMegolmInSession ** outSession)\r
+{\r
+    if (client->numMegolmInSessions < NUM_MEGOLM_SESSIONS)\r
+    {\r
+        MatrixMegolmInSession * result =\r
+            &client->megolmInSessions[client->numMegolmInSessions];\r
+        \r
+        MatrixMegolmInSessionInit(result,\r
+            roomId,\r
+            sessionId,\r
+            sessionKey, strlen(sessionKey));\r
+        \r
+        *outSession = result;\r
+\r
+        client->numMegolmInSessions++;\r
+\r
+        return true;\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientRequestMegolmInSession(\r
+    MatrixClient * client,\r
+    const char * roomId,\r
+    const char * sessionId,\r
+    const char * senderKey,\r
+    const char * userId,\r
+    const char * deviceId)\r
+{\r
+    // TODO: cancel requests\r
+    MatrixClientSendDummy(client, userId, deviceId);\r
+\r
+    STATIC char event[ROOMKEY_REQUEST_SIZE];\r
+    snprintf(event, ROOMKEY_REQUEST_SIZE,\r
+        "{"\r
+            "\"action\":\"request\","\r
+            "\"body\":{"\r
+                "\"algorithm\":\"m.megolm.v1.aes-sha2\","\r
+                "\"room_id\":\"%s\","\r
+                "\"sender_key\":\"%s\","\r
+                "\"session_id\":\"%s\""\r
+            "},"\r
+            "\"request_id\":\"%lld\","\r
+            "\"requesting_device_id\":\"%s\""\r
+        "}",\r
+        roomId,\r
+        senderKey,\r
+        sessionId,\r
+        time(NULL),\r
+        client->deviceId);\r
+\r
+    \r
+    MatrixClientSendToDevice(client,\r
+        userId,\r
+        deviceId,\r
+        event,\r
+        "m.room_key_request");\r
+\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixClientGetOlmSession(\r
+    MatrixClient * client,\r
+    const char * userId,\r
+    const char * deviceId,\r
+    MatrixOlmSession ** outSession)\r
+{\r
+    (void)userId; //unused for now\r
+\r
+    for (int i = 0; i < client->numOlmSessions; i++)\r
+    {\r
+        if (strcmp(client->olmSessions[i].deviceId, deviceId) == 0)\r
+        {\r
+            *outSession = &client->olmSessions[i];\r
+            return true;\r
+        }\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientNewOlmSessionIn(\r
+    MatrixClient * client,\r
+    const char * userId,\r
+    const char * deviceId,\r
+    const char * encrypted,\r
+    MatrixOlmSession ** outSession)\r
+{\r
+    (void)userId; //unused for now\r
+    \r
+    if (client->numOlmSessions < NUM_OLM_SESSIONS)\r
+    {\r
+        STATIC char deviceKey[DEVICE_KEY_SIZE];\r
+        MatrixClientRequestDeviceKey(client,\r
+            deviceId,\r
+            deviceKey, DEVICE_KEY_SIZE);\r
+\r
+        MatrixOlmSessionFrom(\r
+            &client->olmSessions[client->numOlmSessions],\r
+            client->olmAccount.account,\r
+            deviceId,\r
+            deviceKey,\r
+            encrypted);\r
+\r
+        *outSession = &client->olmSessions[client->numOlmSessions];\r
+        \r
+        client->numOlmSessions++;\r
+\r
+        return true;\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientNewOlmSessionOut(\r
+    MatrixClient * client,\r
+    const char * userId,\r
+    const char * deviceId,\r
+    MatrixOlmSession ** outSession)\r
+{\r
+    if (client->numOlmSessions < NUM_OLM_SESSIONS)\r
+    {\r
+        STATIC char deviceKey[DEVICE_KEY_SIZE];\r
+        MatrixClientRequestDeviceKey(client,\r
+            deviceId,\r
+            deviceKey, DEVICE_KEY_SIZE);\r
+\r
+        char onetimeKey[ONETIME_KEY_SIZE];\r
+        MatrixClientClaimOnetimeKey(client,\r
+            userId,\r
+            deviceId,\r
+            onetimeKey, ONETIME_KEY_SIZE);\r
+\r
+        MatrixOlmSessionTo(\r
+            &client->olmSessions[client->numOlmSessions],\r
+            client->olmAccount.account,\r
+            deviceId,\r
+            deviceKey,\r
+            onetimeKey);\r
+\r
+        *outSession = &client->olmSessions[client->numOlmSessions];\r
+        \r
+        client->numOlmSessions++;\r
+\r
+        return true;\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#put_matrixclientv3sendtodeviceeventtypetxnid\r
+bool\r
+MatrixClientSendToDevice(\r
+    MatrixClient * client,\r
+    const char * userId,\r
+    const char * deviceId,\r
+    const char * message,\r
+    const char * msgType)\r
+{\r
+    STATIC char requestUrl[MAX_URL_LEN];\r
+    snprintf(requestUrl, MAX_URL_LEN,\r
+        TODEVICE_URL, msgType, (int)time(NULL));\r
+\r
+    snprintf(g_TodeviceEventBuffer, TODEVICE_EVENT_SIZE,\r
+        "{"\r
+            "\"messages\":{"\r
+                "\"%s\":{"\r
+                    "\"%s\":%s"\r
+                "}"\r
+            "}"\r
+        "}",\r
+        userId,\r
+        deviceId,\r
+        message);\r
+\r
+    STATIC char responseBuffer[ROOM_SEND_RESPONSE_SIZE];\r
+    bool result =\r
+        MatrixHttpPut(client->hc,\r
+            requestUrl,\r
+            g_TodeviceEventBuffer,\r
+            responseBuffer, ROOM_SEND_RESPONSE_SIZE,\r
+            true);\r
+    \r
+    return result;\r
+}\r
+\r
+bool\r
+MatrixClientSendToDeviceEncrypted(\r
+    MatrixClient * client,\r
+    const char * userId,\r
+    const char * deviceId,\r
+    const char * message,\r
+    const char * msgType)\r
+{\r
+    // get olm session\r
+    MatrixOlmSession * olmSession;\r
+    if (! MatrixClientGetOlmSession(client, userId, deviceId, &olmSession))\r
+        MatrixClientNewOlmSessionOut(client, userId, deviceId, &olmSession);\r
+\r
+    // create event json\r
+    char targetDeviceKey[DEVICE_KEY_SIZE];\r
+    MatrixClientRequestDeviceKey(client, deviceId, targetDeviceKey, DEVICE_KEY_SIZE);\r
+    char targetSigningKey[SIGNING_KEY_SIZE];\r
+    MatrixClientRequestSigningKey(client, deviceId, targetSigningKey, SIGNING_KEY_SIZE);\r
+    \r
+    char thisSigningKey[DEVICE_KEY_SIZE];\r
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, DEVICE_KEY_SIZE);\r
+\r
+    snprintf(g_TodeviceEventBuffer, TODEVICE_EVENT_SIZE,\r
+        "{"\r
+        "\"type\":\"%s\","\r
+        "\"content\":%s,"\r
+        "\"sender\":\"%s\","\r
+        "\"recipient\":\"%s\","\r
+        "\"recipient_keys\":{"\r
+        "\"ed25519\":\"%s\""\r
+        "},"\r
+        "\"keys\":{"\r
+        "\"ed25519\":\"%s\""\r
+        "}"\r
+        "}",\r
+        msgType,\r
+        message,\r
+        client->userId,\r
+        userId, // recipient user id\r
+        targetSigningKey, // recipient device key\r
+        thisSigningKey);\r
+\r
+    // encrypt\r
+    MatrixOlmSessionEncrypt(olmSession,\r
+        g_TodeviceEventBuffer,\r
+        g_EncryptedRequestBuffer, ENCRYPTED_REQUEST_SIZE);\r
+\r
+    char thisDeviceKey[DEVICE_KEY_SIZE];\r
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);\r
+\r
+    snprintf(g_EncryptedEventBuffer, ENCRYPTED_EVENT_SIZE,\r
+        "{"\r
+        "\"algorithm\":\"m.olm.v1.curve25519-aes-sha2\","\r
+        "\"ciphertext\":{"\r
+          "\"%s\":{"\r
+            "\"body\":\"%s\","\r
+            "\"type\":%d"\r
+          "}"\r
+        "},"\r
+        "\"device_id\":\"%s\","\r
+        "\"sender_key\":\"%s\""\r
+        "}",\r
+        targetDeviceKey,\r
+        // olm_encrypt_message_length(olmSession->session, strlen(g_TodeviceEventBuffer)), g_EncryptedRequestBuffer,\r
+        g_EncryptedRequestBuffer,\r
+        olm_session_has_received_message(olmSession->session),\r
+        client->deviceId,\r
+        thisDeviceKey);\r
+\r
+    // send\r
+    return MatrixClientSendToDevice(\r
+        client,\r
+        userId,\r
+        deviceId,\r
+        g_EncryptedEventBuffer,\r
+        "m.room.encrypted");\r
+}\r
+\r
+bool\r
+MatrixClientSendDummy(\r
+    MatrixClient * client,\r
+    const char * userId,\r
+    const char * deviceId)\r
+{\r
+    return MatrixClientSendToDeviceEncrypted(\r
+        client,\r
+        userId,\r
+        deviceId,\r
+        "{}",\r
+        "m.dummy");\r
+}\r
+\r
+bool\r
+MatrixClientFindDevice(\r
+    MatrixClient * client,\r
+    const char * deviceId,\r
+    MatrixDevice ** outDevice)\r
+{\r
+    for (int i = 0; i < client->numDevices; i++)\r
+    {\r
+        if (strcmp(client->devices[i].deviceId, deviceId) == 0)\r
+        {\r
+            *outDevice = &client->devices[i];\r
+            return true;\r
+        }\r
+    }\r
+\r
+    MatrixClientRequestDeviceKeys(client);\r
+\r
+    for (int i = 0; i < client->numDevices; i++)\r
+    {\r
+        if (strcmp(client->devices[i].deviceId, deviceId) == 0)\r
+        {\r
+            *outDevice = &client->devices[i];\r
+            return true;\r
+        }\r
+    }\r
+\r
+    *outDevice = NULL;\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientRequestDeviceKey(\r
+    MatrixClient * client,\r
+    const char * deviceId,\r
+    char * outDeviceKey, int outDeviceKeyCap)\r
+{\r
+    MatrixDevice * device;\r
+    \r
+    if (MatrixClientFindDevice(client, deviceId, &device))\r
+    {\r
+        strncpy(outDeviceKey, device->deviceKey, outDeviceKeyCap);\r
+        return true;\r
+    }\r
+\r
+    MatrixClientRequestDeviceKeys(client);\r
+    \r
+    if (MatrixClientFindDevice(client, deviceId, &device))\r
+    {\r
+        strncpy(outDeviceKey, device->deviceKey, outDeviceKeyCap);\r
+        return true;\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientRequestSigningKey(\r
+    MatrixClient * client,\r
+    const char * deviceId,\r
+    char * outSigningKey, int outSigningKeyCap)\r
+{\r
+    MatrixDevice * device;\r
+    \r
+    if (MatrixClientFindDevice(client, deviceId, &device))\r
+    {\r
+        strncpy(outSigningKey, device->signingKey, outSigningKeyCap);\r
+        return true;\r
+    }\r
+\r
+    MatrixClientRequestDeviceKeys(client);\r
+    \r
+    if (MatrixClientFindDevice(client, deviceId, &device))\r
+    {\r
+        strncpy(outSigningKey, device->signingKey, outSigningKeyCap);\r
+        return true;\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+bool\r
+MatrixClientRequestMasterKey(\r
+    MatrixClient * client,\r
+    char * outMasterKey, int outMasterKeyCap)\r
+{\r
+    if (strlen(client->masterKey) > 0) {\r
+        strncpy(outMasterKey, client->masterKey, outMasterKeyCap);\r
+        return true;\r
+    }\r
+\r
+    MatrixClientRequestDeviceKeys(client);\r
+    \r
+    if (strlen(client->masterKey) > 0) {\r
+        strncpy(outMasterKey, client->masterKey, outMasterKeyCap);\r
+        return true;\r
+    }\r
+\r
+    return false;\r
+}\r
+\r
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysquery\r
+bool\r
+MatrixClientRequestDeviceKeys(\r
+    MatrixClient * client)\r
+{\r
+    if (client->numDevices >= NUM_DEVICES) {\r
+        printf("error: Maximum number of devices reached\n");\r
+        return false;\r
+    }\r
+\r
+    // escape userId so we can use it in json queries\r
+    STATIC char userIdEscaped[USER_ID_SIZE];\r
+    JsonEscape(client->userId, strlen(client->userId),\r
+        userIdEscaped, USER_ID_SIZE);\r
+\r
+    // construct and send request\r
+    STATIC char request[KEYS_QUERY_REQUEST_SIZE];\r
+    snprintf(request, KEYS_QUERY_REQUEST_SIZE,\r
+        "{\"device_keys\":{\"%s\":[]}}", client->userId);\r
+\r
+    STATIC char responseBuffer[KEYS_QUERY_RESPONSE_SIZE];\r
+    bool requestResult = MatrixHttpPost(client->hc,\r
+        KEYS_QUERY_URL,\r
+        request,\r
+        responseBuffer, KEYS_QUERY_RESPONSE_SIZE,\r
+        true);\r
+\r
+    if (! requestResult)\r
+        return false;\r
+\r
+    // query for retrieving device keys for user id\r
+    STATIC char query[JSON_QUERY_SIZE];\r
+    const char * s;\r
+    int slen;\r
+\r
+    // look for master key\r
+    snprintf(query, JSON_QUERY_SIZE,\r
+        "$.master_keys.%s.keys", userIdEscaped);\r
+    mjson_find(responseBuffer, strlen(responseBuffer),\r
+        query, &s, &slen);\r
+    \r
+    int koff, klen, voff, vlen, vtype, off = 0;\r
+    for (off = 0; (off = mjson_next(s, slen, off, &koff, &klen,\r
+                                    &voff, &vlen, &vtype)) != 0; ) {\r
+        snprintf(client->masterKey, MASTER_KEY_SIZE,\r
+            "%.*s", vlen-2, s+voff+1);\r
+    }\r
+\r
+    // iterate over returned devices for that userId\r
+    snprintf(query, JSON_QUERY_SIZE,\r
+        "$.device_keys.%s", userIdEscaped);\r
+    \r
+    mjson_find(responseBuffer, strlen(responseBuffer),\r
+        query, &s, &slen);\r
+    \r
+    // loop over keys\r
+    // creating a new device if possible\r
+    for (off = 0; (off = mjson_next(s, slen, off, &koff, &klen,\r
+                                    &voff, &vlen, &vtype)) != 0; ) {\r
+        const char * key = s + koff;\r
+        const char * val = s + voff;\r
+\r
+        // set device id, "key" is the JSON key\r
+        MatrixDevice d;\r
+        snprintf(d.deviceId, DEVICE_ID_SIZE,\r
+            "%.*s", klen-2, key+1);\r
+\r
+        // look for device key in value\r
+        STATIC char deviceKeyQuery[JSON_QUERY_SIZE];\r
+        snprintf(deviceKeyQuery, JSON_QUERY_SIZE,\r
+            "$.keys.curve25519:%s", d.deviceId);\r
+        mjson_get_string(val, vlen,\r
+            deviceKeyQuery, d.deviceKey, DEVICE_KEY_SIZE);\r
+\r
+        // look for signing key in value\r
+        STATIC char signingKeyQuery[JSON_QUERY_SIZE];\r
+        snprintf(signingKeyQuery, JSON_QUERY_SIZE,\r
+            "$.keys.ed25519:%s", d.deviceId);\r
+        mjson_get_string(val, vlen,\r
+            signingKeyQuery, d.signingKey, SIGNING_KEY_SIZE);\r
+\r
+        // add device\r
+        if (client->numDevices < NUM_DEVICES)\r
+        {\r
+            bool foundDevice = false;\r
+            for (int i = 0; i < client->numDevices; i++)\r
+                if (strcmp(client->devices[i].deviceId, d.deviceId) == 0)\r
+                    foundDevice = true;\r
+\r
+            if (! foundDevice) {\r
+                client->devices[client->numDevices] = d;\r
+                client->numDevices++;\r
+            }\r
+        }\r
+        else\r
+        {\r
+            return false;\r
+        }\r
+    }\r
+\r
+    return true;\r
+}\r
+\r
+bool\r
+MatrixClientDeleteDevice(\r
+    MatrixClient * client)\r
+{\r
+    STATIC char deleteRequest[1024];\r
+    snprintf(deleteRequest, 1024,\r
+        "{\"devices\":[\"%s\"]}",\r
+        client->deviceId);\r
+    STATIC char deleteResponse[1024];\r
+    bool res = MatrixHttpPost(client->hc, "/_matrix/client/v3/delete_devices",\r
+        deleteRequest, deleteResponse, 1024, true);\r
+    return res;\r
+}\r