X-Git-Url: https://gitweb.ps.run/matrix_esp_thesis/blobdiff_plain/5cb22046a33f24c1a696990f95e13d534efef497..9eaa420b7bf51cc81c50e7f4ca0f256498a07c86:/src/matrix.c

diff --git a/src/matrix.c b/src/matrix.c
index 790f0f5..ef094b8 100644
--- a/src/matrix.c
+++ b/src/matrix.c
@@ -1,82 +1,1667 @@
 #include "matrix.h"
 
+#include <time.h>
 #include <stdio.h>
 #include <mjson.h>
 
+#ifdef ESP_PLATFORM
+#include <esp_random.h>
+#endif
+
+#define STATIC
 
 #define LOGIN_REQUEST_SIZE 1024
 #define LOGIN_RESPONSE_SIZE 1024
 #define LOGIN_URL "/_matrix/client/v3/login"
 
+#define ENCRYPTED_REQUEST_SIZE (1024*5)
+#define ENCRYPTED_EVENT_SIZE (1024*10)
+#define ROOM_SEND_REQUEST_SIZE 256
+#define ROOM_SEND_RESPONSE_SIZE 1024
+#define ROOM_SEND_URL "/_matrix/client/v3/rooms/%s/send/%s/%d"
+
+#define ROOMKEY_REQUEST_SIZE (1024*4)
+
+#define TODEVICE_EVENT_SIZE (1024*5)
+#define TODEVICE_URL "/_matrix/client/v3/sendToDevice/%s/%d"
+
+#define KEYS_QUERY_URL "/_matrix/client/v3/keys/query"
+#define KEYS_QUERY_REQUEST_SIZE 256
+#define KEYS_QUERY_RESPONSE_SIZE (1024*10)
+
+#define KEYS_UPLOAD_URL "/_matrix/client/v3/keys/upload"
+#define KEYS_UPLOAD_REQUEST_SIZE 1024*4
+#define KEYS_UPLOAD_REQUEST_SIGNED_SIZE 2048*4
+#define KEYS_UPLOAD_RESPONSE_SIZE 2048
+
+#define KEYS_CLAIM_URL "/_matrix/client/v3/keys/claim"
+#define KEYS_CLAIM_REQUEST_SIZE 1024
+#define KEYS_CLAIM_RESPONSE_SIZE 1024
+
+#define SYNC_TIMEOUT 5000
+
+#define JSON_QUERY_SIZE 128
+#define JSON_MAX_INDICES 100
+#define JSON_MAX_ENTRY_SIZE 1024
+
+#define MAX(a,b) ((a) > (b) ? (a) : (b))
+#define MIN(a,b) ((a) < (b) ? (a) : (b))
+
+void
+Randomize(
+    uint8_t * random,
+    int randomLen)
+{
+    #ifdef ESP_PLATFORM
+
+    for (int i = 0; i < randomLen; i++)
+    {
+        random[i] = esp_random() % 256;
+    }
+
+    #else
+
+    STATIC bool first = true;
+    if (first) { srand(time(0)); first = false; }
+
+    for (int i = 0; i < randomLen; i++)
+    {
+        random[i] = rand() % 256;
+    }
+
+    #endif
+}
+
+bool
+JsonEscape(
+    const char * sIn, int sInLen,
+    char * sOut, int sOutCap)
+{
+    int sOutIndex = 0;
+
+    for (int i = 0; i < sInLen; i++)
+    {
+        if (i >= sOutCap)
+            return false;
+        
+        if (sIn[i] == '.' ||
+            sIn[i] == '[' ||
+            sIn[i] == ']'
+        ) {
+            sOut[sOutIndex++] = '\\';
+        }
+        sOut[sOutIndex++] = sIn[i];
+    }
+
+    if (sOutIndex < sOutCap)
+        sOut[sOutIndex] = '\0';
+
+    return true;
+}
+
+bool
+JsonCanonicalize(
+    const char * sIn, int sInLen,
+    char * sOut, int sOutCap)
+{
+    snprintf(sOut, sOutCap, "{}");
+
+    int koff, klen, voff, vlen, vtype, off;
+
+    struct Key {
+        const char * ptr;
+        int len;
+    };
+
+    struct Key keys[JSON_MAX_INDICES];
+    int numKeys = 0;
+
+    for (off = 0; (off = mjson_next(sIn, sInLen, off, &koff, &klen, &voff, &vlen, &vtype)) != 0; ) {
+        keys[numKeys].ptr = sIn + koff;
+        keys[numKeys].len = klen;
+        numKeys++;
+    }
+
+    for (int i = 0; i < numKeys; i++) {
+        for (int j = i; j < numKeys; j++) {
+            if (
+                strncmp(
+                    keys[i].ptr,
+                    keys[j].ptr,
+                    MIN(keys[i].len, keys[j].len)
+                ) > 0
+            ) {
+                struct Key k = keys[i];
+                keys[i] = keys[j];
+                keys[j] = k;
+            }
+        }
+    }
+
+    for (int i = 0; i < numKeys; i++) {
+        char jp[JSON_QUERY_SIZE];
+        snprintf(jp, JSON_QUERY_SIZE, "$.%.*s", keys[i].len-2, keys[i].ptr+1);
+
+        const char * valPtr;
+        int valLen;
+        mjson_find(sIn, sInLen, jp, &valPtr, &valLen);
+        
+        STATIC char newEntry[JSON_MAX_ENTRY_SIZE];
+        snprintf(newEntry, JSON_MAX_ENTRY_SIZE, "{%.*s:%.*s}", keys[i].len, keys[i].ptr, valLen, valPtr);
+
+        char * buffer = strdup(sOut);
+
+        struct mjson_fixedbuf fb = { sOut, sOutCap, 0 };
+        mjson_merge(buffer, strlen(buffer), newEntry, strlen(newEntry), mjson_print_fixed_buf, &fb);
+
+        free(buffer);
+    }
+
+    // TODO: recursively sort entries
+
+    return true;
+}
+
+bool JsonSign(
+    MatrixClient * client,
+    const char * sIn, int sInLen,
+    char * sOut, int sOutCap)
+{
+    STATIC char signature[OLM_SIGNATURE_SIZE];
+    size_t res =
+        olm_account_sign(client->olmAccount.account,
+            sIn, sInLen,
+            signature, OLM_SIGNATURE_SIZE);
+    
+    int signatureLen = res;
+    
+    STATIC char thisSigningKey[SIGNING_KEY_SIZE];
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, SIGNING_KEY_SIZE);
+
+    STATIC char signatureJson[JSON_SIGNATURE_SIZE];
+    int signatureJsonLen =
+        mjson_snprintf(signatureJson, JSON_SIGNATURE_SIZE,
+            "{"
+                "\"signatures\":{"
+                    "\"%s\":{"
+                        "\"ed25519:%s\":\"%.*s\""
+                    "}"
+                "}"
+            "}",
+            client->userId,
+            //"1",
+            client->deviceId,
+            signatureLen, signature);
+
+    struct mjson_fixedbuf result = { sOut, sOutCap, 0 };
+    mjson_merge(
+        sIn, sInLen,
+        signatureJson, signatureJsonLen,
+        mjson_print_fixed_buf,
+        &result);
+
+    return true;
+}
+
+
+bool
+MatrixOlmAccountInit(
+    MatrixOlmAccount * account)
+{
+    account->account = olm_account(account->memory);
+
+    STATIC uint8_t random[OLM_ACCOUNT_RANDOM_SIZE];
+    Randomize(random, OLM_ACCOUNT_RANDOM_SIZE);
+
+    size_t res = olm_create_account(
+        account->account,
+        random,
+        OLM_ACCOUNT_RANDOM_SIZE);
+
+    return res != olm_error();
+}
+
+bool
+MatrixOlmAccountUnpickle(
+    MatrixOlmAccount * account,
+    void * pickled, int pickledLen,
+    const void * key, int keyLen)
+{
+    size_t res;
+    res = olm_unpickle_account(account->account,
+        key, keyLen,
+        pickled, pickledLen);
+    if (res == olm_error()) {
+        printf("error unpickling olm account:%s\n",
+            olm_account_last_error(account->account));
+    }
+    return res != olm_error();
+}
+
+bool
+MatrixOlmAccountGetDeviceKey(
+    MatrixOlmAccount * account,
+    char * key, int keyCap)
+{
+    STATIC char deviceKeysJson[OLM_IDENTITY_KEYS_JSON_SIZE];
+    size_t res =
+        olm_account_identity_keys(account->account,
+            deviceKeysJson, OLM_IDENTITY_KEYS_JSON_SIZE);
+    mjson_get_string(deviceKeysJson, res,
+        "$.curve25519",
+        key, keyCap);
+    return true;
+}
+
+bool
+MatrixOlmAccountGetSigningKey(
+    MatrixOlmAccount * account,
+    char * key, int keyCap)
+{
+    STATIC char deviceKeysJson[OLM_IDENTITY_KEYS_JSON_SIZE];
+    size_t res =
+        olm_account_identity_keys(account->account,
+            deviceKeysJson, OLM_IDENTITY_KEYS_JSON_SIZE);
+    mjson_get_string(deviceKeysJson, res,
+        "$.ed25519",
+        key, keyCap);
+    return true;
+}
+
+bool
+MatrixOlmSessionFrom(
+    MatrixOlmSession * session,
+    OlmAccount * olmAccount,
+    const char * deviceId,
+    const char * deviceKey,
+    const char * encrypted)
+{
+    memset(session, 0, sizeof(MatrixOlmSession));
+
+    session->deviceId = deviceId;
+
+    session->session =
+        olm_session(session->memory);
+    
+    char * encryptedCopy = strdup(encrypted);
+    
+    size_t res =
+        olm_create_inbound_session_from(session->session, olmAccount,
+            deviceKey, strlen(deviceKey),
+            encryptedCopy, strlen(encryptedCopy));
+    
+    if (res == olm_error()) {
+        printf("error olm:%s\n", olm_session_last_error(session->session));
+    }
+
+    return res != olm_error();
+}
+
+bool
+MatrixOlmSessionTo(
+    MatrixOlmSession * session,
+    OlmAccount * olmAccount,
+    const char * deviceId,
+    const char * deviceKey,
+    const char * deviceOnetimeKey)
+{
+    memset(session, 0, sizeof(MatrixOlmSession));
+
+    session->deviceId = deviceId;
+
+    session->session =
+        olm_session(session->memory);
+
+    STATIC uint8_t random[OLM_OUTBOUND_SESSION_RANDOM_SIZE];
+    Randomize(random, OLM_OUTBOUND_SESSION_RANDOM_SIZE);
+
+    size_t res =
+        olm_create_outbound_session(session->session,
+            olmAccount,
+            deviceKey, strlen(deviceKey),
+            deviceOnetimeKey, strlen(deviceOnetimeKey),
+            random, OLM_OUTBOUND_SESSION_RANDOM_SIZE);
+    
+    if (res == olm_error()) {
+        printf("error olm:%s\n", olm_session_last_error(session->session));
+    }
+
+    return res != olm_error();
+}
+
+bool
+MatrixOlmSessionUnpickle(
+    MatrixOlmSession * session,
+    const char * deviceId,
+    void * pickled, int pickledLen,
+    const void * key, int keyLen)
+{
+    memset(session, 0, sizeof(MatrixOlmSession));
+
+    session->deviceId = deviceId;
+
+    session->session =
+        olm_session(session->memory);
+    
+    size_t res;
+    res = olm_unpickle_session(session->session,
+        key, keyLen,
+        pickled, pickledLen);
+    
+    if (res == olm_error()) {
+        printf("error unpickling olm session:%s\n", olm_session_last_error(session->session));
+    }
+
+    return res != olm_error();
+}
+
+bool
+MatrixOlmSessionEncrypt(
+    MatrixOlmSession * session,
+    const char * plaintext,
+    char * outBuffer, int outBufferCap)
+{
+    STATIC uint8_t random[OLM_ENCRYPT_RANDOM_SIZE];
+    Randomize(random, OLM_ENCRYPT_RANDOM_SIZE);
+
+    size_t res = olm_encrypt(session->session,
+        plaintext, strlen(plaintext),
+        random, OLM_ENCRYPT_RANDOM_SIZE,
+        outBuffer, outBufferCap);
+
+    return res != olm_error();
+}
+
+bool
+MatrixOlmSessionDecrypt(
+    MatrixOlmSession * session,
+    size_t messageType,
+    char * encrypted,
+    char * outBuffer, int outBufferCap)
+{
+    STATIC uint8_t random[OLM_ENCRYPT_RANDOM_SIZE];
+    Randomize(random, OLM_ENCRYPT_RANDOM_SIZE);
+
+    size_t res =
+        olm_decrypt(session->session,
+            messageType,
+            encrypted, strlen(encrypted),
+            outBuffer, outBufferCap);
+    
+    if (res != olm_error() && res < outBufferCap)
+        outBuffer[res] = '\0';
+
+    return res != olm_error();
+}
+
+bool
+MatrixMegolmInSessionInit(
+    MatrixMegolmInSession * session,
+    const char * roomId,
+    const char * sessionId,
+    const char * sessionKey, int sessionKeyLen)
+{
+    memset(session, 0, sizeof(MatrixMegolmInSession));
+    
+    strncpy(session->roomId, roomId, sizeof(session->roomId));
+    strncpy(session->id, sessionId, sizeof(session->id));
+    strncpy(session->key, sessionKey, sizeof(session->key));
+
+    session->session =
+        olm_inbound_group_session(session->memory);
+
+    size_t res =
+        olm_init_inbound_group_session(
+        // olm_import_inbound_group_session(
+            session->session,
+            (const uint8_t *)sessionKey, sessionKeyLen);
+    if (res == olm_error()) {
+        printf("Error initializing Megolm session: %s\n", olm_inbound_group_session_last_error(session->session));
+    }
+
+    return res != olm_error();
+}
+
+bool
+MatrixMegolmInSessionDecrypt(
+    MatrixMegolmInSession * session,
+    const char * encrypted, int encryptedLen,
+    char * outDecrypted, int outDecryptedCap)
+{
+    // uint8_t buffer[1024];
+    // memcpy(buffer, encrypted, encryptedLen);
+
+    uint32_t megolmInMessageIndex;
+
+    size_t res =
+        olm_group_decrypt(session->session,
+            (uint8_t *)encrypted, encryptedLen,
+            (uint8_t *)outDecrypted, outDecryptedCap,
+            &megolmInMessageIndex);
+    
+    printf("message index: %d\n", (int)megolmInMessageIndex);
+    
+    if (res == olm_error()) {
+        printf("error decrypting megolm message: %s\n", olm_inbound_group_session_last_error(session->session));
+    }
+    else {
+        printf("decrypted len: %d\n", res);
+    }
+    
+    return true;
+}
+
+// https://matrix.org/docs/guides/end-to-end-encryption-implementation-guide#starting-a-megolm-session
+bool
+MatrixMegolmOutSessionInit(
+    MatrixMegolmOutSession * session,
+    const char * roomId)
+{
+    memset(session, 0, sizeof(MatrixMegolmOutSession));
+
+    STATIC uint8_t random[MEGOLM_INIT_RANDOM_SIZE];
+    Randomize(random, MEGOLM_INIT_RANDOM_SIZE);
+
+    strncpy(session->roomId, roomId, ROOM_ID_SIZE);
+
+    session->session =
+        olm_outbound_group_session(session->memory);
+
+    olm_init_outbound_group_session(
+        session->session,
+        random,
+        MEGOLM_INIT_RANDOM_SIZE);
+
+    olm_outbound_group_session_id(session->session,
+        (uint8_t *)session->id,
+        MEGOLM_SESSION_ID_SIZE);
+        
+    olm_outbound_group_session_key(session->session,
+        (uint8_t *)session->key,
+        MEGOLM_SESSION_KEY_SIZE);
+    
+    return true;
+}
+
+bool
+MatrixMegolmOutSessionEncrypt(
+    MatrixMegolmOutSession * session,
+    const char * plaintext,
+    char * outBuffer, int outBufferCap)
+{
+    size_t res = olm_group_encrypt(session->session,
+        (uint8_t *)plaintext, strlen(plaintext),
+        (uint8_t *)outBuffer, outBufferCap);
+
+    return res != olm_error();
+}
+
+bool
+MatrixMegolmOutSessionSave(
+    MatrixMegolmOutSession * session,
+    const char * filename,
+    const char * key)
+{
+    FILE * f = fopen(filename, "w");
+
+    size_t roomIdLen = strlen(session->roomId);
+    fwrite(&roomIdLen, sizeof(size_t), 1, f);
+    fwrite(session->roomId, 1, roomIdLen, f);
+
+    size_t pickleBufferLen =
+        olm_pickle_outbound_group_session_length(
+            session->session);
+    void * pickleBuffer = malloc(pickleBufferLen);
+
+    olm_pickle_outbound_group_session(
+        session->session,
+        key, strlen(key),
+        pickleBuffer, pickleBufferLen);
+    
+    fwrite(&pickleBufferLen, sizeof(size_t), 1, f);
+    fwrite(pickleBuffer, 1, pickleBufferLen, f);
+    free(pickleBuffer);
+
+    fclose(f);
+
+    return true;
+}
+
+bool
+MatrixMegolmOutSessionLoad(
+    MatrixMegolmOutSession * session,
+    const char * filename,
+    const char * key)
+{
+    FILE * f = fopen(filename, "r");
+
+    size_t roomIdLen;
+    fread(&roomIdLen, sizeof(size_t), 1, f);
+    fread(session->roomId, 1, roomIdLen, f);
+    for (int i = roomIdLen; i < ROOM_ID_SIZE; i++)
+        session->roomId[i] = '\0';
+
+    size_t pickleBufferLen;
+    fread(&pickleBufferLen, sizeof(size_t), 1, f);
+
+    void * pickleBuffer = malloc(pickleBufferLen);
+    fread(pickleBuffer, 1, pickleBufferLen, f);
+
+    olm_unpickle_outbound_group_session(
+        session->session,
+        key, strlen(key),
+        pickleBuffer, pickleBufferLen);
+    
+    free(pickleBuffer);
+
+    olm_outbound_group_session_id(session->session, (uint8_t *)session->id, MEGOLM_SESSION_ID_SIZE);
+    olm_outbound_group_session_key(session->session, (uint8_t *)session->key, MEGOLM_SESSION_KEY_SIZE);
+
+    fclose(f);
+
+    return true;
+}
+
+
 
 bool
 MatrixClientInit(
+    MatrixClient * client)
+{
+    memset(client, 0, sizeof(MatrixClient));
+
+    // init olm account
+    MatrixOlmAccountInit(&client->olmAccount);
+
+    return true;
+}
+
+bool
+MatrixClientSave(
     MatrixClient * client,
-    char * server, int serverLen)
+    const char * filename)
 {
-    strcpy_s(
-        client->server,
-        SERVER_SIZE,
-        server
-    );
-    client->serverLen = serverLen;
+    FILE * f = fopen(filename, "w");
+    
+    
+    char thisDeviceKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);
+    char thisSigningKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, DEVICE_KEY_SIZE);
+
+
+    fwrite(thisDeviceKey, 1, DEVICE_KEY_SIZE, f);
+    fwrite(thisSigningKey, 1, DEVICE_KEY_SIZE, f);
+    fwrite(client->userId, 1, USER_ID_SIZE, f);
+    fwrite(client->accessToken, 1, ACCESS_TOKEN_SIZE, f);
+    fwrite(client->deviceId, 1, DEVICE_ID_SIZE, f);
+    fwrite(client->expireMs, 1, EXPIRE_MS_SIZE, f);
+    fwrite(client->refreshToken, 1, REFRESH_TOKEN_SIZE, f);
 
+    fwrite(&client->numDevices, sizeof(int), 1, f);
+    for (int i = 0; i < client->numDevices; i++) {
+        fwrite(client->devices[i].deviceId, 1, DEVICE_ID_SIZE, f);
+        fwrite(client->devices[i].deviceKey, 1, DEVICE_KEY_SIZE, f);
+    }
+
+    fclose(f);
     return true;
 }
 
-// https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3login
 bool
-MatrixClientLoginPassword(
+MatrixClientLoad(
     MatrixClient * client,
-    char * username, int usernameLen,
-    char * password, int passwordLen,
-    char * displayName, int displayNameLen)
+    const char * filename)
 {
-    static char requestBuffer[LOGIN_REQUEST_SIZE];
+    FILE * f = fopen(filename, "r");
+    
+    
+    char thisDeviceKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);
+    char thisSigningKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, DEVICE_KEY_SIZE);
+
+
+    fread(thisDeviceKey, 1, DEVICE_KEY_SIZE, f);
+    fread(thisSigningKey, 1, DEVICE_KEY_SIZE, f);
+    fread(client->userId, 1, USER_ID_SIZE, f);
+    fread(client->accessToken, 1, ACCESS_TOKEN_SIZE, f);
+    fread(client->deviceId, 1, DEVICE_ID_SIZE, f);
+    fread(client->expireMs, 1, EXPIRE_MS_SIZE, f);
+    fread(client->refreshToken, 1, REFRESH_TOKEN_SIZE, f);
+
+    fread(&client->numDevices, sizeof(int), 1, f);
+    for (int i = 0; i < client->numDevices; i++) {
+        fread(client->devices[i].deviceId, 1, DEVICE_ID_SIZE, f);
+        fread(client->devices[i].deviceKey, 1, DEVICE_KEY_SIZE, f);
+    }
+
+    fclose(f);
+    return true;
+}
+
+bool
+MatrixClientSetAccessToken(
+    MatrixClient * client,
+    const char * accessToken)
+{
+    for (int i = 0; i < ACCESS_TOKEN_SIZE-1; i++)
+        client->accessToken[i] = accessToken[i];
+    client->accessToken[ACCESS_TOKEN_SIZE-1] = '\0';
+
+    return true;
+}
+
+bool
+MatrixClientSetDeviceId(
+    MatrixClient * client,
+    const char * deviceId)
+{
+    for (int i = 0; i < DEVICE_ID_SIZE-1; i++)
+        client->deviceId[i] = deviceId[i];
+    client->deviceId[DEVICE_ID_SIZE-1] = '\0';
+
+    return true;
+}
+
+bool
+MatrixClientSetUserId(
+    MatrixClient * client,
+    const char * userId)
+{
+    for (int i = 0; i < USER_ID_SIZE-1; i++)
+        client->userId[i] = userId[i];
+    client->userId[USER_ID_SIZE-1] = '\0';
+
+    return true;
+}
+
+bool
+MatrixClientGenerateOnetimeKeys(
+    MatrixClient * client,
+    int numberOfKeys)
+{
+    STATIC uint8_t random[OLM_ONETIME_KEYS_RANDOM_SIZE];
+    Randomize(random, OLM_ONETIME_KEYS_RANDOM_SIZE);
+
+    size_t res =
+        olm_account_generate_one_time_keys(client->olmAccount.account,
+            numberOfKeys, random, OLM_ONETIME_KEYS_RANDOM_SIZE);
+
+    return res != olm_error();
+}
+
+// https://spec.matrix.org/v1.7/client-server-api/#post_matrixclientv3keysupload
+bool
+MatrixClientUploadOnetimeKeys(
+    MatrixClient * client)
+{
+    STATIC char requestBuffer[KEYS_UPLOAD_REQUEST_SIZE];
+
+    mjson_snprintf(requestBuffer, KEYS_UPLOAD_REQUEST_SIZE,
+        "{");
+
+    STATIC char onetimeKeysBuffer[1024];
+    olm_account_one_time_keys(client->olmAccount.account,
+        onetimeKeysBuffer, 1024);
+
+    const char *keys;
+    int keysLen;
+    mjson_find(onetimeKeysBuffer, strlen(onetimeKeysBuffer), "$.curve25519", &keys, &keysLen);
+
+    int koff, klen, voff, vlen, vtype, off = 0;
+    while ((off = mjson_next(keys, keysLen, off, &koff, &klen, &voff, &vlen, &vtype)) != 0) {
+        STATIC char keyJson[JSON_ONETIME_KEY_SIZE];
+        
+        int keyJsonLen =
+            snprintf(keyJson, JSON_ONETIME_KEY_SIZE,
+                "{\"key\":\"%.*s\"}",
+                vlen-2, keys + voff+1);
+
+        STATIC char keyJsonSigned[JSON_ONETIME_KEY_SIGNED_SIZE];
 
-    int requestLen =
-        mjson_snprintf(requestBuffer, LOGIN_REQUEST_SIZE,
+        JsonSign(client,
+            keyJson, keyJsonLen,
+            keyJsonSigned, JSON_ONETIME_KEY_SIGNED_SIZE);
+        
+        mjson_snprintf(requestBuffer+strlen(requestBuffer), KEYS_UPLOAD_REQUEST_SIZE-strlen(requestBuffer),
+            "\"signed_curve25519:%.*s\":%s,",
+            klen-2, keys + koff+1,
+            keyJsonSigned);
+    }
+
+    if (requestBuffer[strlen(requestBuffer)-1] == ',')
+        requestBuffer[strlen(requestBuffer)-1] = '\0';
+
+    mjson_snprintf(requestBuffer+strlen(requestBuffer), KEYS_UPLOAD_REQUEST_SIZE-strlen(requestBuffer),
+        "}");
+        
+    // STATIC char onetimeKeysSignedBuffer[KEYS_UPLOAD_REQUEST_SIGNED_SIZE];
+    // JsonSign(client,
+    //     requestBuffer, strlen(requestBuffer),
+    //     onetimeKeysSignedBuffer, KEYS_UPLOAD_REQUEST_SIZE);
+        
+    // STATIC char finalEvent[KEYS_UPLOAD_REQUEST_SIGNED_SIZE];
+    // snprintf(finalEvent, KEYS_UPLOAD_REQUEST_SIGNED_SIZE,
+    // "{\"one_time_keys\":%s}", onetimeKeysSignedBuffer);
+    STATIC char finalEvent[KEYS_UPLOAD_REQUEST_SIGNED_SIZE];
+    snprintf(finalEvent, KEYS_UPLOAD_REQUEST_SIGNED_SIZE,
+    "{\"one_time_keys\":%s}", requestBuffer);
+
+    STATIC char responseBuffer[KEYS_UPLOAD_RESPONSE_SIZE];
+    MatrixHttpPost(client->hc,
+        KEYS_UPLOAD_URL,
+        finalEvent,
+        responseBuffer, KEYS_UPLOAD_RESPONSE_SIZE,
+        true);
+
+    return true;
+}
+
+// https://spec.matrix.org/v1.7/client-server-api/#post_matrixclientv3keysupload
+bool
+MatrixClientUploadDeviceKey(
+    MatrixClient * client)
+{
+    char thisDeviceKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);
+    char thisSigningKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, DEVICE_KEY_SIZE);
+
+    STATIC char deviceKeysBuffer[KEYS_UPLOAD_REQUEST_SIZE];
+
+    int deviceKeysBufferLen =
+        mjson_snprintf(deviceKeysBuffer, KEYS_UPLOAD_REQUEST_SIZE,
             "{"
-                "\"type\": \"m.login.password\","
-                "\"identifier\": {"
-                    "\"type\": \"m.id.user\","
-                    "\"user\": \"%.*s\""
+                "\"algorithms\":[\"m.olm.v1.curve25519-aes-sha2\",\"m.megolm.v1.aes-sha2\"],"
+                "\"device_id\":\"%s\","
+                "\"keys\":{"
+                    "\"curve25519:%s\":\"%s\","
+                    "\"ed25519:%s\":\"%s\""
                 "},"
-                "\"password\": \"%.*s\","
-                "\"initial_device_display_name\": \"%.*s\""
+                "\"user_id\":\"%s\""
             "}",
-            usernameLen, username,
-            passwordLen, password,
-            displayNameLen, displayName);
+            client->deviceId,
+            client->deviceId, thisDeviceKey,
+            client->deviceId, thisSigningKey,
+            client->userId);
+
+    STATIC char deviceKeysSignedBuffer[KEYS_UPLOAD_REQUEST_SIGNED_SIZE];
+    JsonSign(client,
+        deviceKeysBuffer, deviceKeysBufferLen,
+        deviceKeysSignedBuffer, KEYS_UPLOAD_REQUEST_SIZE);
+    
+    STATIC char finalEvent[KEYS_UPLOAD_REQUEST_SIGNED_SIZE+30];
+    snprintf(finalEvent, KEYS_UPLOAD_REQUEST_SIGNED_SIZE+30,
+    "{\"device_keys\":%s}", deviceKeysSignedBuffer);
+
+    STATIC char responseBuffer[KEYS_UPLOAD_RESPONSE_SIZE];
+    MatrixHttpPost(client->hc,
+        KEYS_UPLOAD_URL,
+        finalEvent,
+        responseBuffer, KEYS_UPLOAD_RESPONSE_SIZE,
+        true);
+
+    return true;
+}
+
+// https://spec.matrix.org/v1.7/client-server-api/#post_matrixclientv3keysclaim
+bool
+MatrixClientClaimOnetimeKey(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    char * outOnetimeKey, int outOnetimeKeyCap)
+{
+    STATIC char requestBuffer[KEYS_CLAIM_REQUEST_SIZE];
+    mjson_snprintf(requestBuffer, KEYS_CLAIM_REQUEST_SIZE,
+    "{"
+      "\"one_time_keys\":{"
+        "\"%s\":{"
+          "\"%s\":\"signed_curve25519\""
+        "}"
+      "},"
+      "\"timeout\":10000"
+    "}",
+    userId,
+    deviceId);
+
+    STATIC char responseBuffer[KEYS_CLAIM_RESPONSE_SIZE];
+    MatrixHttpPost(client->hc,
+        KEYS_CLAIM_URL,
+        requestBuffer,
+        responseBuffer, KEYS_CLAIM_RESPONSE_SIZE,
+        true);
+    
+    STATIC char userIdEscaped[USER_ID_SIZE];
+    JsonEscape(userId, strlen(userId),
+        userIdEscaped, USER_ID_SIZE);
     
-    static char responseBuffer[LOGIN_RESPONSE_SIZE];
-    int responseLen;
+    STATIC char query[JSON_QUERY_SIZE];
+    snprintf(query, JSON_QUERY_SIZE,
+        "$.one_time_keys.%s.%s",
+        userIdEscaped,
+        deviceId);
+    
+    const char * keyObject;
+    int keyObjectSize;
+    mjson_find(responseBuffer, strlen(responseBuffer),
+        query,
+        &keyObject, &keyObjectSize);
+    
+    int koff, klen, voff, vlen, vtype;
+    mjson_next(keyObject, keyObjectSize, 0,
+        &koff, &klen, &voff, &vlen, &vtype);
+    
+    mjson_get_string(keyObject + voff, vlen,
+        "$.key", outOnetimeKey, outOnetimeKeyCap);
+    
+    // TODO:verify signature
+    
+    return true;
+}
+
+// https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3login
+bool
+MatrixClientLoginPassword(
+    MatrixClient * client,
+    const char * username,
+    const char * password,
+    const char * displayName)
+{
+    STATIC char requestBuffer[LOGIN_REQUEST_SIZE];
+
+    mjson_snprintf(requestBuffer, LOGIN_REQUEST_SIZE,
+        "{"
+            "\"type\":\"m.login.password\","
+            "\"identifier\":{"
+                "\"type\":\"m.id.user\","
+                "\"user\":\"%s\""
+            "},"
+            "\"password\":\"%s\","
+            "\"initial_device_display_name\":\"%s\""
+        "}",
+        username,
+        password,
+        displayName);
+    
+    STATIC char responseBuffer[LOGIN_RESPONSE_SIZE];
     bool result =
-        MatrixHttpPost(client,
+        MatrixHttpPost(client->hc,
             LOGIN_URL,
-            requestBuffer, requestLen,
-            responseBuffer, LOGIN_RESPONSE_SIZE, &responseLen);
+            requestBuffer,
+            responseBuffer, LOGIN_RESPONSE_SIZE,
+            false);
     
     if (!result)
         return false;
+    
+    int responseLen = strlen(responseBuffer);
+
+    mjson_get_string(responseBuffer, responseLen,
+        "$.access_token",
+        client->accessToken, ACCESS_TOKEN_SIZE);
+    mjson_get_string(responseBuffer, responseLen,
+        "$.device_id",
+        client->deviceId, DEVICE_ID_SIZE);
+    mjson_get_string(responseBuffer, responseLen,
+        "$.expires_in_ms",
+        client->expireMs, EXPIRE_MS_SIZE);
+    mjson_get_string(responseBuffer, responseLen,
+        "$.refresh_token",
+        client->refreshToken, REFRESH_TOKEN_SIZE);
+        
+    MatrixHttpSetAccessToken(client->hc, client->accessToken);
+
+    return true;
+}
+
+// https://spec.matrix.org/v1.6/client-server-api/#put_matrixclientv3roomsroomidsendeventtypetxnid
+bool
+MatrixClientSendEvent(
+    MatrixClient * client,
+    const char * roomId,
+    const char * msgType,
+    const char * msgBody)
+{    
+    STATIC char requestUrl[MAX_URL_LEN];
+    sprintf(requestUrl,
+        ROOM_SEND_URL, roomId, msgType, (int)time(NULL));
+
+    STATIC char responseBuffer[ROOM_SEND_RESPONSE_SIZE];
+    bool result =
+        MatrixHttpPut(client->hc,
+            requestUrl,
+            msgBody,
+            responseBuffer, ROOM_SEND_RESPONSE_SIZE,
+            true);
+    
+    return result;
+}
+
+// https://spec.matrix.org/v1.6/client-server-api/#mroomencrypted
+// https://matrix.org/docs/guides/end-to-end-encryption-implementation-guide#sending-an-encrypted-message-event
+bool
+MatrixClientSendEventEncrypted(
+    MatrixClient * client,
+    const char * roomId,
+    const char * msgType,
+    const char * msgBody)
+{
+    // event json
+    STATIC char requestBuffer[ROOM_SEND_REQUEST_SIZE];
+    sprintf(requestBuffer,
+        "{"
+        "\"type\":\"%s\","
+        "\"content\":%s,"
+        "\"room_id\":\"%s\""
+        "}",
+        msgType,
+        msgBody,
+        roomId);
+
+    // get megolm session
+    MatrixMegolmOutSession * outSession;
+    if (! MatrixClientGetMegolmOutSession(client, roomId, &outSession))
+        MatrixClientNewMegolmOutSession(client, roomId, &outSession);
+        
+    // encrypt
+    STATIC char encryptedBuffer[ENCRYPTED_REQUEST_SIZE/10];
+    MatrixMegolmOutSessionEncrypt(outSession,
+        requestBuffer,
+        encryptedBuffer, ENCRYPTED_REQUEST_SIZE);
+
+    char thisDeviceKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);
+    
+
+    // encrypted event json
+    const char * senderKey = thisDeviceKey;
+    const char * sessionId = outSession->id;
+    const char * deviceId = client->deviceId;
+
+    STATIC char encryptedEventBuffer[ENCRYPTED_EVENT_SIZE/10];
+    sprintf(encryptedEventBuffer,
+        "{"
+        "\"algorithm\":\"m.megolm.v1.aes-sha2\","
+        "\"ciphertext\":\"%s\","
+        "\"device_id\":\"%s\","
+        "\"sender_key\":\"%s\","
+        "\"session_id\":\"%s\""
+        "}",
+        encryptedBuffer,
+        deviceId,
+        senderKey,
+        sessionId);
+
+    // send
+    return MatrixClientSendEvent(client,
+        roomId,
+        "m.room.encrypted",
+        encryptedEventBuffer);
+}
+
+// https://spec.matrix.org/v1.6/client-server-api/#get_matrixclientv3sync
+bool
+MatrixClientSync(
+    MatrixClient * client,
+    char * outSyncBuffer, int outSyncCap,
+    const char * nextBatch)
+{
+    // filter={\"event_fields\":[\"to_device\"]}
+    STATIC char url[MAX_URL_LEN];
+    snprintf(url, MAX_URL_LEN,
+        "/_matrix/client/v3/sync?timeout=%d%s",
+        SYNC_TIMEOUT,
+        strlen(nextBatch) > 0 ? "&since=" : "");
+    
+    int index = strlen(url);
+
+    for (size_t i = 0; i < strlen(nextBatch); i++) {
+        char c = nextBatch[i];
+
+        if (c == '~') {
+            url[index++] = '%';
+            url[index++] = '7';
+            url[index++] = 'E';
+        }
+        else {
+            url[index++] = c;
+        }
+    }
+    url[index] = '\0';
+
+    return
+        MatrixHttpGet(client->hc,
+            url,
+            outSyncBuffer, outSyncCap,
+            true);
+}
+
+// https://spec.matrix.org/v1.7/client-server-api/#get_matrixclientv3roomsroomideventeventid
+bool
+MatrixClientGetRoomEvent(
+    MatrixClient * client,
+    const char * roomId,
+    const char * eventId,
+    char * outEvent, int outEventCap)
+{
+    STATIC char url[MAX_URL_LEN];
+    snprintf(url, MAX_URL_LEN,
+        "/_matrix/client/v3/rooms/%s/event/%s",
+            roomId,
+            eventId);
+
+    return
+        MatrixHttpGet(client->hc,
+            url,
+            outEvent, outEventCap,
+            true);
+}
+
+bool
+MatrixClientShareMegolmOutSession(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    MatrixMegolmOutSession * session)
+{
+    // generate room key event
+    STATIC char eventBuffer[KEY_SHARE_EVENT_LEN];
+    sprintf(eventBuffer,
+        "{"
+            "\"algorithm\":\"m.megolm.v1.aes-sha2\","
+            "\"room_id\":\"%s\","
+            "\"session_id\":\"%s\","
+            "\"session_key\":\"%s\""
+        "}",
+        session->roomId,
+        session->id,
+        session->key
+    );
+
+    // send
+    MatrixClientSendToDeviceEncrypted(client,
+        userId,
+        deviceId,
+        eventBuffer,
+        "m.room_key");
+
+    return true;
+}
+
+bool
+MatrixClientShareMegolmOutSessionTest(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    MatrixMegolmOutSession * session)
+{
+    // generate room key event
+    char eventBuffer[KEY_SHARE_EVENT_LEN];
+    sprintf(eventBuffer,
+        "{"
+            "\"algorithm\":\"m.megolm.v1.aes-sha2\","
+            "\"room_id\":\"%s\","
+            "\"session_id\":\"%s\","
+            "\"session_key\":\"%s\""
+        "}",
+        session->roomId,
+        session->id,
+        session->key
+    );
+
+    // send
+    MatrixClientSendToDevice(client,
+        userId,
+        deviceId,
+        eventBuffer,
+        "m.room_key");
+
+    return true;
+}
+
+bool
+MatrixClientGetMegolmOutSession(
+    MatrixClient * client,
+    const char * roomId,
+    MatrixMegolmOutSession ** outSession)
+{
+    for (int i = 0; i < client->numMegolmOutSessions; i++)
+    {
+        if (strcmp(client->megolmOutSessions[i].roomId, roomId) == 0)
+        {
+            *outSession = &client->megolmOutSessions[i];
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool
+MatrixClientNewMegolmOutSession(
+    MatrixClient * client,
+    const char * roomId,
+    MatrixMegolmOutSession ** outSession)
+{
+    if (client->numMegolmOutSessions < NUM_MEGOLM_SESSIONS)
+    {
+        MatrixMegolmOutSession * result =
+            &client->megolmOutSessions[client->numMegolmOutSessions];
+        
+        MatrixMegolmOutSessionInit(result,
+            roomId);
+
+        *outSession = result;
+
+        client->numMegolmOutSessions++;
+
+        return true;
+    }
+
+    return false;
+}
+
+bool
+MatrixClientGetMegolmInSession(
+    MatrixClient * client,
+    const char * roomId, int roomIdLen,
+    const char * sessionId, int sessionIdLen,
+    MatrixMegolmInSession ** outSession)
+{
+    for (int i = 0; i < client->numMegolmInSessions; i++)
+    {
+        if (strncmp(client->megolmInSessions[i].roomId, roomId, roomIdLen) == 0 &&
+            strncmp(client->megolmInSessions[i].id, sessionId, sessionIdLen) == 0)
+        {
+            *outSession = &client->megolmInSessions[i];
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool
+MatrixClientNewMegolmInSession(
+    MatrixClient * client,
+    const char * roomId,
+    const char * sessionId,
+    const char * sessionKey,
+    MatrixMegolmInSession ** outSession)
+{
+    if (client->numMegolmInSessions < NUM_MEGOLM_SESSIONS)
+    {
+        MatrixMegolmInSession * result =
+            &client->megolmInSessions[client->numMegolmInSessions];
+        
+        MatrixMegolmInSessionInit(result,
+            roomId,
+            sessionId,
+            sessionKey, strlen(sessionKey));
+        
+        *outSession = result;
+
+        client->numMegolmInSessions++;
+
+        return true;
+    }
+
+    return false;
+}
+
+bool
+MatrixClientRequestMegolmInSession(
+    MatrixClient * client,
+    const char * roomId,
+    const char * sessionId,
+    const char * senderKey,
+    const char * userId,
+    const char * deviceId)
+{
+    // TODO: cancel requests
+    MatrixClientSendDummy(client, userId, deviceId);
+
+    STATIC char event[ROOMKEY_REQUEST_SIZE];
+    snprintf(event, ROOMKEY_REQUEST_SIZE,
+        "{"
+            "\"action\":\"request\","
+            "\"body\":{"
+                "\"algorithm\":\"m.megolm.v1.aes-sha2\","
+                "\"room_id\":\"%s\","
+                "\"sender_key\":\"%s\","
+                "\"session_id\":\"%s\""
+            "},"
+            "\"request_id\":\"%lld\","
+            "\"requesting_device_id\":\"%s\""
+        "}",
+        roomId,
+        senderKey,
+        sessionId,
+        time(NULL),
+        client->deviceId);
+
+    
+    MatrixClientSendToDevice(client,
+        userId,
+        deviceId,
+        event,
+        "m.room_key_request");
+
+    return true;
+}
+
+bool
+MatrixClientGetOlmSessionIn(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    MatrixOlmSession ** outSession)
+{
+    for (int i = 0; i < client->numOlmSessions; i++)
+    {
+        if (strcmp(client->olmSessions[i].deviceId, deviceId) == 0)
+        {
+            *outSession = &client->olmSessions[i];
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool
+MatrixClientNewOlmSessionIn(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    const char * encrypted,
+    MatrixOlmSession ** outSession)
+{
+    if (client->numOlmSessions < NUM_OLM_SESSIONS)
+    {
+        STATIC char deviceKey[DEVICE_KEY_SIZE];
+        MatrixClientRequestDeviceKey(client,
+            deviceId,
+            deviceKey, DEVICE_KEY_SIZE);
+
+        MatrixOlmSessionFrom(
+            &client->olmSessions[client->numOlmSessions],
+            client->olmAccount.account,
+            deviceId,
+            deviceKey,
+            encrypted);
+
+        *outSession = &client->olmSessions[client->numOlmSessions];
+        
+        client->numOlmSessions++;
+
+        return true;
+    }
+
+    return false;
+}
+
+bool
+MatrixClientGetOlmSessionOut(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    MatrixOlmSession ** outSession)
+{
+    for (int i = 0; i < client->numOlmSessions; i++)
+    {
+        if (strcmp(client->olmSessions[i].deviceId, deviceId) == 0)
+        {
+            *outSession = &client->olmSessions[i];
+            return true;
+        }
+    }
+
+    return false;
+}
+
+bool
+MatrixClientNewOlmSessionOut(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    MatrixOlmSession ** outSession)
+{
+    if (client->numOlmSessions < NUM_OLM_SESSIONS)
+    {
+        STATIC char deviceKey[DEVICE_KEY_SIZE];
+        MatrixClientRequestDeviceKey(client,
+            deviceId,
+            deviceKey, DEVICE_KEY_SIZE);
+
+        char onetimeKey[ONETIME_KEY_SIZE];
+        MatrixClientClaimOnetimeKey(client,
+            userId,
+            deviceId,
+            onetimeKey, ONETIME_KEY_SIZE);
+
+        MatrixOlmSessionTo(
+            &client->olmSessions[client->numOlmSessions],
+            client->olmAccount.account,
+            deviceId,
+            deviceKey,
+            onetimeKey);
+
+        *outSession = &client->olmSessions[client->numOlmSessions];
+        
+        client->numOlmSessions++;
+
+        return true;
+    }
+
+    return false;
+}
+
+// https://spec.matrix.org/v1.6/client-server-api/#put_matrixclientv3sendtodeviceeventtypetxnid
+bool
+MatrixClientSendToDevice(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    const char * message,
+    const char * msgType)
+{
+    STATIC char requestUrl[MAX_URL_LEN];
+    sprintf(requestUrl,
+        TODEVICE_URL, msgType, (int)time(NULL));
+
+    STATIC char eventBuffer[TODEVICE_EVENT_SIZE];
+    snprintf(eventBuffer, TODEVICE_EVENT_SIZE,
+        "{"
+            "\"messages\":{"
+                "\"%s\":{"
+                    "\"%s\":%s"
+                "}"
+            "}"
+        "}",
+        userId,
+        deviceId,
+        message);
+
+    STATIC char responseBuffer[ROOM_SEND_RESPONSE_SIZE];
+    bool result =
+        MatrixHttpPut(client->hc,
+            requestUrl,
+            eventBuffer,
+            responseBuffer, ROOM_SEND_RESPONSE_SIZE,
+            true);
+    
+    printf("%s\n", responseBuffer);
+    
+    return result;
+}
+
+bool
+MatrixClientSendToDeviceEncrypted(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    const char * message,
+    const char * msgType)
+{
+    // get olm session
+    MatrixOlmSession * olmSession;
+    if (! MatrixClientGetOlmSessionOut(client, userId, deviceId, &olmSession))
+        MatrixClientNewOlmSessionOut(client, userId, deviceId, &olmSession);
+
+    // create event json
+    char targetDeviceKey[DEVICE_KEY_SIZE];
+    MatrixClientRequestDeviceKey(client, deviceId, targetDeviceKey, DEVICE_KEY_SIZE);
+    char targetSigningKey[SIGNING_KEY_SIZE];
+    MatrixClientRequestSigningKey(client, deviceId, targetSigningKey, SIGNING_KEY_SIZE);
+    
+    char thisSigningKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, DEVICE_KEY_SIZE);
+
+    STATIC char eventBuffer[TODEVICE_EVENT_SIZE];
+    sprintf(eventBuffer,
+        "{"
+        "\"type\":\"%s\","
+        "\"content\":%s,"
+        "\"sender\":\"%s\","
+        "\"recipient\":\"%s\","
+        "\"recipient_keys\":{"
+          "\"ed25519\":\"%s\""
+        "},"
+        "\"keys\":{"
+          "\"ed25519\":\"%s\""
+        "}"
+        "}",
+        msgType,
+        message,
+        client->userId,
+        userId, // recipient user id
+        targetSigningKey, // recipient device key
+        thisSigningKey);
+
+    // encrypt
+    STATIC char encryptedBuffer[ENCRYPTED_REQUEST_SIZE];
+    MatrixOlmSessionEncrypt(olmSession,
+        eventBuffer,
+        encryptedBuffer, ENCRYPTED_REQUEST_SIZE);
+
+    char thisDeviceKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);
+
+
+    STATIC char encryptedEventBuffer[ENCRYPTED_EVENT_SIZE];
+    sprintf(encryptedEventBuffer,
+        "{"
+        "\"algorithm\":\"m.olm.v1.curve25519-aes-sha2\","
+        "\"ciphertext\":{"
+          "\"%s\":{"
+            "\"body\":\"%s\","
+            "\"type\":%d"
+          "}"
+        "},"
+        "\"device_id\":\"%s\","
+        "\"sender_key\":\"%s\""
+        "}",
+        targetDeviceKey,
+        encryptedBuffer,
+        olm_session_has_received_message(olmSession->session),
+        client->deviceId,
+        thisDeviceKey);
+
+    // send
+    return MatrixClientSendToDevice(
+        client,
+        userId,
+        deviceId,
+        encryptedEventBuffer,
+        "m.room.encrypted");
+}
+
+bool
+MatrixClientSendDummy(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId)
+{
+    return MatrixClientSendToDeviceEncrypted(
+        client,
+        userId,
+        deviceId,
+        "{}",
+        "m.dummy");
+}
+
+bool
+MatrixClientFindDevice(
+    MatrixClient * client,
+    const char * deviceId,
+    MatrixDevice ** outDevice)
+{
+    MatrixClientRequestDeviceKeys(client);
+
+    for (int i = 0; i < client->numDevices; i++)
+    {
+        if (strcmp(client->devices[i].deviceId, deviceId) == 0)
+        {
+            *outDevice = &client->devices[i];
+            return true;
+        }
+    }
+
+    *outDevice = NULL;
+    return false;
+}
+
+bool
+MatrixClientRequestDeviceKey(
+    MatrixClient * client,
+    const char * deviceId,
+    char * outDeviceKey, int outDeviceKeyCap)
+{
+    MatrixDevice * device;
+    
+    if (MatrixClientFindDevice(client, deviceId, &device))
+    {
+        strncpy(outDeviceKey, device->deviceKey, outDeviceKeyCap);
+        return true;
+    }
+
+    MatrixClientRequestDeviceKeys(client);
+    
+    if (MatrixClientFindDevice(client, deviceId, &device))
+    {
+        strncpy(outDeviceKey, device->deviceKey, outDeviceKeyCap);
+        return true;
+    }
+
+    return false;
+}
+
+bool
+MatrixClientRequestSigningKey(
+    MatrixClient * client,
+    const char * deviceId,
+    char * outSigningKey, int outSigningKeyCap)
+{
+    MatrixDevice * device;
+    
+    if (MatrixClientFindDevice(client, deviceId, &device))
+    {
+        strncpy(outSigningKey, device->signingKey, outSigningKeyCap);
+        return true;
+    }
+
+    MatrixClientRequestDeviceKeys(client);
+    
+    if (MatrixClientFindDevice(client, deviceId, &device))
+    {
+        strncpy(outSigningKey, device->signingKey, outSigningKeyCap);
+        return true;
+    }
+
+    return false;
+}
+
+// https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3keysquery
+bool
+MatrixClientRequestDeviceKeys(
+    MatrixClient * client)
+{
+    if (client->numDevices >= NUM_DEVICES) {
+        printf("Maximum number of devices reached\n");
+        return false;
+    }
+
+    STATIC char userIdEscaped[USER_ID_SIZE];
+    JsonEscape(client->userId, strlen(client->userId),
+        userIdEscaped, USER_ID_SIZE);
 
-    client->accessTokenLen =
-        mjson_get_string(responseBuffer, responseLen,
-            "$.access_token",
-            client->accessTokenBuffer, ACCESS_TOKEN_SIZE);
-    client->deviceIdLen =
-        mjson_get_string(responseBuffer, responseLen,
-            "$.device_id",
-            client->deviceIdBuffer, DEVICE_ID_SIZE);
-    client->expireMsLen =
-        mjson_get_string(responseBuffer, responseLen,
-            "$.expires_in_ms",
-            client->expireMsBuffer, EXPIRE_MS_SIZE);
-    client->refreshTokenLen =
-        mjson_get_string(responseBuffer, responseLen,
-            "$.refresh_token",
-            client->refreshTokenBuffer, REFRESH_TOKEN_SIZE);
+    STATIC char request[KEYS_QUERY_REQUEST_SIZE];
+    snprintf(request, KEYS_QUERY_REQUEST_SIZE,
+        "{\"device_keys\":{\"%s\":[]}}", client->userId);
+
+    STATIC char responseBuffer[KEYS_QUERY_RESPONSE_SIZE];
+    bool requestResult = MatrixHttpPost(client->hc,
+        KEYS_QUERY_URL,
+        request,
+        responseBuffer, KEYS_QUERY_RESPONSE_SIZE,
+        true);
+
+    if (! requestResult)
+        return false;
+
+    // query for retrieving device keys for user id
+    STATIC char query[JSON_QUERY_SIZE];
+    snprintf(query, JSON_QUERY_SIZE,
+        "$.device_keys.%s", userIdEscaped);
+    
+    const char * s;
+    int slen;
+    mjson_find(responseBuffer, strlen(responseBuffer),
+        query, &s, &slen);
+    
+    // loop over keys
+    
+    int koff, klen, voff, vlen, vtype, off = 0;
+    for (off = 0; (off = mjson_next(s, slen, off, &koff, &klen,
+                                    &voff, &vlen, &vtype)) != 0; ) {
+        const char * key = s + koff;
+        const char * val = s + voff;
+
+        // set device id, "key" is the JSON key
+        MatrixDevice d;
+        snprintf(d.deviceId, DEVICE_ID_SIZE,
+            "%.*s", klen-2, key+1);
+
+        // look for device key in value
+        STATIC char deviceKeyQuery[JSON_QUERY_SIZE];
+        snprintf(deviceKeyQuery, JSON_QUERY_SIZE,
+            "$.keys.curve25519:%s", d.deviceId);
+        mjson_get_string(val, vlen,
+            deviceKeyQuery, d.deviceKey, DEVICE_KEY_SIZE);
+
+        // look for signing key in value
+        STATIC char signingKeyQuery[JSON_QUERY_SIZE];
+        snprintf(signingKeyQuery, JSON_QUERY_SIZE,
+            "$.keys.ed25519:%s", d.deviceId);
+        mjson_get_string(val, vlen,
+            signingKeyQuery, d.signingKey, SIGNING_KEY_SIZE);
+
+        // add device
+        if (client->numDevices < NUM_DEVICES)
+        {
+            bool foundDevice = false;
+            for (int i = 0; i < client->numDevices; i++)
+                if (strcmp(client->devices[i].deviceId, d.deviceId) == 0)
+                    foundDevice = true;
+
+            if (! foundDevice) {
+                printf("new device: %s %s %s\n", d.deviceId, d.deviceKey, d.signingKey);
+                client->devices[client->numDevices] = d;
+                client->numDevices++;
+            }
+        }
+        else
+        {
+            return false;
+        }
+    }
 
     return true;
 }
 
+bool
+MatrixClientDeleteDevice(
+    MatrixClient * client)
+{
+    STATIC char deleteRequest[1024];
+    snprintf(deleteRequest, 1024,
+        "{\"devices\":[\"%s\"]}",
+        client->deviceId);
+    STATIC char deleteResponse[1024];
+    bool res = MatrixHttpPost(client->hc, "/_matrix/client/v3/delete_devices",
+        deleteRequest, deleteResponse, 1024, true);
+    return res;
+}
\ No newline at end of file