X-Git-Url: https://gitweb.ps.run/matrix_esp_thesis/blobdiff_plain/464bfb1912d0806143386f61c33dd45fbafc38e8..HEAD:/src/matrix.c

diff --git a/src/matrix.c b/src/matrix.c
index 80802c3..8b186ca 100644
--- a/src/matrix.c
+++ b/src/matrix.c
@@ -3,50 +3,83 @@
 #include <time.h>
 #include <stdio.h>
 #include <mjson.h>
+#include <olm/sas.h>
 
+#ifdef ESP_PLATFORM
+#include <esp_random.h>
+#endif
 
+// can be used to disable static allocation
+#define STATIC static
+
+// DEFINES
 #define LOGIN_REQUEST_SIZE 1024
 #define LOGIN_RESPONSE_SIZE 1024
 #define LOGIN_URL "/_matrix/client/v3/login"
 
 #define ENCRYPTED_REQUEST_SIZE (1024*5)
+STATIC char g_EncryptedRequestBuffer[ENCRYPTED_REQUEST_SIZE];
 #define ENCRYPTED_EVENT_SIZE (1024*10)
-#define ROOMEVENT_REQUEST_SIZE 256
-#define ROOMEVENT_RESPONSE_SIZE 1024
-#define ROOMEVENT_URL "/_matrix/client/v3/rooms/%s/send/%s/%d"
+STATIC char g_EncryptedEventBuffer[ENCRYPTED_EVENT_SIZE];
+#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)
+STATIC char g_TodeviceEventBuffer[TODEVICE_EVENT_SIZE];
 #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_QUERY_RESPONSE_SIZE (1024*5)
 
 #define KEYS_UPLOAD_URL "/_matrix/client/v3/keys/upload"
-#define KEYS_UPLOAD_REQUEST_SIZE 1024
-#define KEYS_UPLOAD_REQUEST_SIGNED_SIZE 2048
+#define KEYS_UPLOAD_REQUEST_SIZE 1024*4
+STATIC char g_KeysUploadRequestBuffer[KEYS_UPLOAD_REQUEST_SIZE];
+#define KEYS_UPLOAD_REQUEST_SIGNED_SIZE 2048*4
+STATIC char g_KeysUploadRequestSignedBuffer[KEYS_UPLOAD_REQUEST_SIGNED_SIZE];
 #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))
 
+// Util
 
 void
 Randomize(
     uint8_t * random,
     int randomLen)
 {
-    static bool first = true;
+    #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
@@ -76,20 +109,86 @@ JsonEscape(
     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];
+    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];
+    STATIC char signatureJson[JSON_SIGNATURE_SIZE];
     int signatureJsonLen =
         mjson_snprintf(signatureJson, JSON_SIGNATURE_SIZE,
             "{"
@@ -100,6 +199,7 @@ bool JsonSign(
                 "}"
             "}",
             client->userId,
+            //"1",
             client->deviceId,
             signatureLen, signature);
 
@@ -113,14 +213,13 @@ bool JsonSign(
     return true;
 }
 
-
 bool
 MatrixOlmAccountInit(
     MatrixOlmAccount * account)
 {
     account->account = olm_account(account->memory);
 
-    static uint8_t random[OLM_ACCOUNT_RANDOM_SIZE];
+    STATIC uint8_t random[OLM_ACCOUNT_RANDOM_SIZE];
     Randomize(random, OLM_ACCOUNT_RANDOM_SIZE);
 
     size_t res = olm_create_account(
@@ -131,7 +230,82 @@ MatrixOlmAccountInit(
     return res != olm_error();
 }
 
-// TODO: in/outbound sessions
+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,
@@ -147,7 +321,7 @@ MatrixOlmSessionTo(
     session->session =
         olm_session(session->memory);
 
-    static uint8_t random[OLM_OUTBOUND_SESSION_RANDOM_SIZE];
+    STATIC uint8_t random[OLM_OUTBOUND_SESSION_RANDOM_SIZE];
     Randomize(random, OLM_OUTBOUND_SESSION_RANDOM_SIZE);
 
     size_t res =
@@ -158,10 +332,36 @@ MatrixOlmSessionTo(
             random, OLM_OUTBOUND_SESSION_RANDOM_SIZE);
     
     if (res == olm_error()) {
-        printf("error olm: %s\n", olm_account_last_error(olmAccount));
+        printf("error olm:%s\n", olm_session_last_error(session->session));
     }
 
-    return session->session != NULL;
+    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
@@ -170,9 +370,10 @@ MatrixOlmSessionEncrypt(
     const char * plaintext,
     char * outBuffer, int outBufferCap)
 {
-    static uint8_t random[OLM_ENCRYPT_RANDOM_SIZE];
+    STATIC uint8_t random[OLM_ENCRYPT_RANDOM_SIZE];
     Randomize(random, OLM_ENCRYPT_RANDOM_SIZE);
 
+    memset(outBuffer, 0, outBufferCap);
     size_t res = olm_encrypt(session->session,
         plaintext, strlen(plaintext),
         random, OLM_ENCRYPT_RANDOM_SIZE,
@@ -181,6 +382,80 @@ MatrixOlmSessionEncrypt(
     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() && (int)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);
+    
+    if (res == olm_error()) {
+        printf("error decrypting megolm message: %s\n", olm_inbound_group_session_last_error(session->session));
+    }
+    
+    return true;
+}
+
 // https://matrix.org/docs/guides/end-to-end-encryption-implementation-guide#starting-a-megolm-session
 bool
 MatrixMegolmOutSessionInit(
@@ -189,10 +464,10 @@ MatrixMegolmOutSessionInit(
 {
     memset(session, 0, sizeof(MatrixMegolmOutSession));
 
-    static uint8_t random[MEGOLM_INIT_RANDOM_SIZE];
+    STATIC uint8_t random[MEGOLM_INIT_RANDOM_SIZE];
     Randomize(random, MEGOLM_INIT_RANDOM_SIZE);
 
-    session->roomId = roomId;
+    strncpy(session->roomId, roomId, ROOM_ID_SIZE);
 
     session->session =
         olm_outbound_group_session(session->memory);
@@ -219,6 +494,7 @@ MatrixMegolmOutSessionEncrypt(
     const char * plaintext,
     char * outBuffer, int outBufferCap)
 {
+    memset(outBuffer, 0, outBufferCap);
     size_t res = olm_group_encrypt(session->session,
         (uint8_t *)plaintext, strlen(plaintext),
         (uint8_t *)outBuffer, outBufferCap);
@@ -227,86 +503,15 @@ MatrixMegolmOutSessionEncrypt(
 }
 
 
-
 bool
 MatrixClientInit(
-    MatrixClient * client,
-    const char * server)
+    MatrixClient * client)
 {
     memset(client, 0, sizeof(MatrixClient));
 
-    strcpy(client->server, server);
-
     // init olm account
     MatrixOlmAccountInit(&client->olmAccount);
 
-    // set device key
-    static char deviceKeysJson[OLM_IDENTITY_KEYS_JSON_SIZE];
-    size_t res =
-        olm_account_identity_keys(
-            client->olmAccount.account,
-            deviceKeysJson,
-            OLM_IDENTITY_KEYS_JSON_SIZE);
-
-    mjson_get_string(deviceKeysJson, res,
-        "$.curve25519",
-        client->deviceKey, DEVICE_KEY_SIZE);
-    mjson_get_string(deviceKeysJson, res,
-        "$.ed25519",
-        client->signingKey, SIGNING_KEY_SIZE);
-
-    return true;
-}
-
-bool
-MatrixClientSave(
-    MatrixClient * client,
-    const char * filename)
-{
-    FILE * f = fopen(filename, "w");
-    
-    fwrite(client->deviceKey, 1, DEVICE_KEY_SIZE, f);
-    fwrite(client->signingKey, 1, DEVICE_KEY_SIZE, f);
-    fwrite(client->userId, 1, USER_ID_SIZE, f);
-    fwrite(client->server, 1, SERVER_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;
-}
-
-bool
-MatrixClientLoad(
-    MatrixClient * client,
-    const char * filename)
-{
-    FILE * f = fopen(filename, "r");
-    
-    fread(client->deviceKey, 1, DEVICE_KEY_SIZE, f);
-    fread(client->signingKey, 1, DEVICE_KEY_SIZE, f);
-    fread(client->userId, 1, USER_ID_SIZE, f);
-    fread(client->server, 1, SERVER_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;
 }
 
@@ -315,14 +520,9 @@ MatrixClientSetAccessToken(
     MatrixClient * client,
     const char * accessToken)
 {
-    int accessTokenLen = strlen(accessToken);
-
-    if (accessTokenLen > ACCESS_TOKEN_SIZE - 1)
-        return false;
-
-    for (int i = 0; i < accessTokenLen; i++)
+    for (int i = 0; i < ACCESS_TOKEN_SIZE-1; i++)
         client->accessToken[i] = accessToken[i];
-    client->accessToken[accessTokenLen] = '\0';
+    client->accessToken[ACCESS_TOKEN_SIZE-1] = '\0';
 
     return true;
 }
@@ -332,14 +532,9 @@ MatrixClientSetDeviceId(
     MatrixClient * client,
     const char * deviceId)
 {
-    int deviceIdLen = strlen(deviceId);
-
-    if (deviceIdLen > DEVICE_ID_SIZE - 1)
-        return false;
-
-    for (int i = 0; i < deviceIdLen; i++)
+    for (int i = 0; i < DEVICE_ID_SIZE-1; i++)
         client->deviceId[i] = deviceId[i];
-    client->deviceId[deviceIdLen] = '\0';
+    client->deviceId[DEVICE_ID_SIZE-1] = '\0';
 
     return true;
 }
@@ -349,14 +544,9 @@ MatrixClientSetUserId(
     MatrixClient * client,
     const char * userId)
 {
-    int userIdLen = strlen(userId);
-
-    if (userIdLen > USER_ID_SIZE - 1)
-        return false;
-
-    for (int i = 0; i < userIdLen; i++)
+    for (int i = 0; i < USER_ID_SIZE-1; i++)
         client->userId[i] = userId[i];
-    client->userId[userIdLen] = '\0';
+    client->userId[USER_ID_SIZE-1] = '\0';
 
     return true;
 }
@@ -366,7 +556,7 @@ MatrixClientGenerateOnetimeKeys(
     MatrixClient * client,
     int numberOfKeys)
 {
-    static uint8_t random[OLM_ONETIME_KEYS_RANDOM_SIZE];
+    STATIC uint8_t random[OLM_ONETIME_KEYS_RANDOM_SIZE];
     Randomize(random, OLM_ONETIME_KEYS_RANDOM_SIZE);
 
     size_t res =
@@ -376,96 +566,112 @@ MatrixClientGenerateOnetimeKeys(
     return res != olm_error();
 }
 
-// https://spec.matrix.org/v1.7/client-server-api/#post_matrixclientv3keysupload
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysupload
 bool
 MatrixClientUploadOnetimeKeys(
     MatrixClient * client)
 {
-    static char requestBuffer[KEYS_UPLOAD_REQUEST_SIZE];
-
-    mjson_snprintf(requestBuffer, KEYS_UPLOAD_REQUEST_SIZE,
-        "{\"one_time_keys\":{");
+    mjson_snprintf(g_KeysUploadRequestBuffer, KEYS_UPLOAD_REQUEST_SIZE,
+        "{");
 
-    static char onetimeKeysBuffer[1024];
+    STATIC char onetimeKeysBuffer[1024];
     olm_account_one_time_keys(client->olmAccount.account,
         onetimeKeysBuffer, 1024);
 
+    // olm_account_one_time_keys returns a json object
+    // find curve25519 member
     const char *keys;
     int keysLen;
     mjson_find(onetimeKeysBuffer, strlen(onetimeKeysBuffer), "$.curve25519", &keys, &keysLen);
 
+    // iterate over onetime keys, create key object
+    // sign it and append to request
     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];
+        STATIC char keyJson[JSON_ONETIME_KEY_SIZE];
         
-        snprintf(keyJson, JSON_ONETIME_KEY_SIZE,
-            "{\"key\":\"%.*s\"}",
-            vlen-2, keys + voff+1);
+        int keyJsonLen =
+            snprintf(keyJson, JSON_ONETIME_KEY_SIZE,
+                "{\"key\":\"%.*s\"}",
+                vlen-2, keys + voff+1);
 
-        static char keyJsonSigned[JSON_ONETIME_KEY_SIGNED_SIZE];
+        STATIC char keyJsonSigned[JSON_ONETIME_KEY_SIGNED_SIZE];
 
         JsonSign(client,
-            keyJson, JSON_ONETIME_KEY_SIZE,
+            keyJson, keyJsonLen,
             keyJsonSigned, JSON_ONETIME_KEY_SIGNED_SIZE);
         
-        mjson_snprintf(requestBuffer+strlen(requestBuffer), KEYS_UPLOAD_REQUEST_SIZE-strlen(requestBuffer),
+        mjson_snprintf(g_KeysUploadRequestBuffer+strlen(g_KeysUploadRequestBuffer), KEYS_UPLOAD_REQUEST_SIZE-strlen(g_KeysUploadRequestBuffer),
             "\"signed_curve25519:%.*s\":%s,",
             klen-2, keys + koff+1,
             keyJsonSigned);
     }
 
-    mjson_snprintf(requestBuffer+strlen(requestBuffer)-1, KEYS_UPLOAD_REQUEST_SIZE-strlen(requestBuffer),
-        "}}");
+    // delete last ',' since the loop always appends it
+    if (g_KeysUploadRequestBuffer[strlen(g_KeysUploadRequestBuffer)-1] == ',')
+        g_KeysUploadRequestBuffer[strlen(g_KeysUploadRequestBuffer)-1] = '\0';
 
-    static char responseBuffer[KEYS_UPLOAD_RESPONSE_SIZE];
-    MatrixHttpPost(client,
+    mjson_snprintf(g_KeysUploadRequestBuffer+strlen(g_KeysUploadRequestBuffer), KEYS_UPLOAD_REQUEST_SIZE-strlen(g_KeysUploadRequestBuffer),
+        "}");
+
+    snprintf(g_KeysUploadRequestSignedBuffer, KEYS_UPLOAD_REQUEST_SIGNED_SIZE,
+    "{\"one_time_keys\":%s}", g_KeysUploadRequestBuffer);
+
+    STATIC char responseBuffer[KEYS_UPLOAD_RESPONSE_SIZE];
+    MatrixHttpPost(client->hc,
         KEYS_UPLOAD_URL,
-        requestBuffer,
+        g_KeysUploadRequestSignedBuffer,
         responseBuffer, KEYS_UPLOAD_RESPONSE_SIZE,
         true);
 
     return true;
 }
 
-// https://spec.matrix.org/v1.7/client-server-api/#post_matrixclientv3keysupload
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysupload
 bool
 MatrixClientUploadDeviceKeys(
     MatrixClient * client)
 {
-    static char deviceKeysBuffer[KEYS_UPLOAD_REQUEST_SIZE];
-
-    mjson_snprintf(deviceKeysBuffer, KEYS_UPLOAD_REQUEST_SIZE,
-        "{\"device_keys\":{"
-            "\"algorithms\":[\"m.olm.v1.curve25519-aes-sha2\",\"m.megolm.v1.aes-sha2\"],"
-            "\"device_id\":\"%s\","
-            "\"keys\":{"
-                "\"curve25519:%s\":\"%s\","
-                "\"ed25519:%s\":\"%s\""
-            "},"
-            "\"user_id\":\"%s\""
-        "}}",
-        client->deviceId,
-        client->deviceId, client->deviceKey,
-        client->deviceId, client->signingKey,
-        client->userId);
+    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 deviceKeysSignedBuffer[KEYS_UPLOAD_REQUEST_SIGNED_SIZE];
-    JsonSign(client,
-        deviceKeysBuffer, KEYS_UPLOAD_REQUEST_SIZE,
-        deviceKeysSignedBuffer, KEYS_UPLOAD_REQUEST_SIZE);
+    int deviceKeysBufferLen =
+        mjson_snprintf(g_KeysUploadRequestBuffer, KEYS_UPLOAD_REQUEST_SIZE,
+            "{"
+                "\"algorithms\":[\"m.olm.v1.curve25519-aes-sha2\",\"m.megolm.v1.aes-sha2\"],"
+                "\"device_id\":\"%s\","
+                "\"keys\":{"
+                    "\"curve25519:%s\":\"%s\","
+                    "\"ed25519:%s\":\"%s\""
+                "},"
+                "\"user_id\":\"%s\""
+            "}",
+            client->deviceId,
+            client->deviceId, thisDeviceKey,
+            client->deviceId, thisSigningKey,
+            client->userId);
 
+    JsonSign(client,
+        g_KeysUploadRequestBuffer, deviceKeysBufferLen,
+        g_KeysUploadRequestSignedBuffer, KEYS_UPLOAD_REQUEST_SIZE);
+    
+    STATIC char finalEvent[KEYS_UPLOAD_REQUEST_SIGNED_SIZE+30];
+    snprintf(finalEvent, KEYS_UPLOAD_REQUEST_SIGNED_SIZE+30,
+    "{\"device_keys\":%s}", g_KeysUploadRequestSignedBuffer);
 
-    static char responseBuffer[KEYS_UPLOAD_RESPONSE_SIZE];
-    MatrixHttpPost(client,
+    STATIC char responseBuffer[KEYS_UPLOAD_RESPONSE_SIZE];
+    MatrixHttpPost(client->hc,
         KEYS_UPLOAD_URL,
-        deviceKeysSignedBuffer,
+        finalEvent,
         responseBuffer, KEYS_UPLOAD_RESPONSE_SIZE,
         true);
 
     return true;
 }
 
-// https://spec.matrix.org/v1.7/client-server-api/#post_matrixclientv3keysclaim
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysclaim
 bool
 MatrixClientClaimOnetimeKey(
     MatrixClient * client,
@@ -473,42 +679,48 @@ MatrixClientClaimOnetimeKey(
     const char * deviceId,
     char * outOnetimeKey, int outOnetimeKeyCap)
 {
-    static char requestBuffer[KEYS_CLAIM_REQUEST_SIZE];
+    STATIC char requestBuffer[KEYS_CLAIM_REQUEST_SIZE];
     mjson_snprintf(requestBuffer, KEYS_CLAIM_REQUEST_SIZE,
     "{"
-      "\"one_time_keys\": {"
-        "\"%s\": {"
-          "\"%s\": \"signed_curve25519\""
+      "\"one_time_keys\":{"
+        "\"%s\":{"
+          "\"%s\":\"signed_curve25519\""
         "}"
       "},"
-      "\"timeout\": 10000"
+      "\"timeout\":10000"
     "}",
     userId,
     deviceId);
 
-    static char responseBuffer[KEYS_CLAIM_RESPONSE_SIZE];
-    MatrixHttpPost(client,
+    STATIC char responseBuffer[KEYS_CLAIM_RESPONSE_SIZE];
+    MatrixHttpPost(client->hc,
         KEYS_CLAIM_URL,
         requestBuffer,
         responseBuffer, KEYS_CLAIM_RESPONSE_SIZE,
         true);
     
-    char userIdEscaped[USER_ID_SIZE];
+    STATIC char userIdEscaped[USER_ID_SIZE];
     JsonEscape(userId, strlen(userId),
         userIdEscaped, USER_ID_SIZE);
     
-    static char query[JSON_QUERY_SIZE];
+    // create the json query according to
+    // https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysclaim
+    STATIC char query[JSON_QUERY_SIZE];
     snprintf(query, JSON_QUERY_SIZE,
         "$.one_time_keys.%s.%s",
         userIdEscaped,
         deviceId);
     
+    // find the corresponding json object
     const char * keyObject;
     int keyObjectSize;
     mjson_find(responseBuffer, strlen(responseBuffer),
         query,
         &keyObject, &keyObjectSize);
     
+    // use mjson_next (which iterates over all key/value pairs) once
+    // because we only request one key
+    // (see https://github.com/cesanta/mjson#mjson_next for details)
     int koff, klen, voff, vlen, vtype;
     mjson_next(keyObject, keyObjectSize, 0,
         &koff, &klen, &voff, &vlen, &vtype);
@@ -521,7 +733,7 @@ MatrixClientClaimOnetimeKey(
     return true;
 }
 
-// https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3login
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3login
 bool
 MatrixClientLoginPassword(
     MatrixClient * client,
@@ -529,35 +741,36 @@ MatrixClientLoginPassword(
     const char * password,
     const char * displayName)
 {
-    static char requestBuffer[LOGIN_REQUEST_SIZE];
+    STATIC char requestBuffer[LOGIN_REQUEST_SIZE];
 
     mjson_snprintf(requestBuffer, LOGIN_REQUEST_SIZE,
         "{"
-            "\"type\": \"m.login.password\","
-            "\"identifier\": {"
-                "\"type\": \"m.id.user\","
-                "\"user\": \"%s\""
+            "\"type\":\"m.login.password\","
+            "\"identifier\":{"
+                "\"type\":\"m.id.user\","
+                "\"user\":\"%s\""
             "},"
-            "\"password\": \"%s\","
-            "\"initial_device_display_name\": \"%s\""
+            "\"password\":\"%s\","
+            "\"initial_device_display_name\":\"%s\""
         "}",
         username,
         password,
         displayName);
     
-    static char responseBuffer[LOGIN_RESPONSE_SIZE];
+    STATIC char responseBuffer[LOGIN_RESPONSE_SIZE];
     bool result =
-        MatrixHttpPost(client,
+        MatrixHttpPost(client->hc,
             LOGIN_URL,
             requestBuffer,
             responseBuffer, LOGIN_RESPONSE_SIZE,
             false);
     
-    int responseLen = strlen(responseBuffer);
-    
     if (!result)
         return false;
+    
+    int responseLen = strlen(responseBuffer);
 
+    // store variables in MatrixClient
     mjson_get_string(responseBuffer, responseLen,
         "$.access_token",
         client->accessToken, ACCESS_TOKEN_SIZE);
@@ -570,11 +783,13 @@ MatrixClientLoginPassword(
     mjson_get_string(responseBuffer, responseLen,
         "$.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
+// https://spec.matrix.org/v1.8/client-server-api/#put_matrixclientv3roomsroomidsendeventtypetxnid
 bool
 MatrixClientSendEvent(
     MatrixClient * client,
@@ -582,22 +797,22 @@ MatrixClientSendEvent(
     const char * msgType,
     const char * msgBody)
 {    
-    static char requestUrl[MAX_URL_LEN];
-    sprintf(requestUrl,
-        ROOMEVENT_URL, roomId, msgType, (int)time(NULL));
+    STATIC char requestUrl[MAX_URL_LEN];
+    snprintf(requestUrl, MAX_URL_LEN,
+        ROOM_SEND_URL, roomId, msgType, (int)time(NULL));
 
-    static char responseBuffer[ROOMEVENT_RESPONSE_SIZE];
+    STATIC char responseBuffer[ROOM_SEND_RESPONSE_SIZE];
     bool result =
-        MatrixHttpPut(client,
+        MatrixHttpPut(client->hc,
             requestUrl,
             msgBody,
-            responseBuffer, ROOMEVENT_RESPONSE_SIZE,
+            responseBuffer, ROOM_SEND_RESPONSE_SIZE,
             true);
     
     return result;
 }
 
-// https://spec.matrix.org/v1.6/client-server-api/#mroomencrypted
+// https://spec.matrix.org/v1.8/client-server-api/#mroomencrypted
 // https://matrix.org/docs/guides/end-to-end-encryption-implementation-guide#sending-an-encrypted-message-event
 bool
 MatrixClientSendEventEncrypted(
@@ -607,8 +822,8 @@ MatrixClientSendEventEncrypted(
     const char * msgBody)
 {
     // event json
-    static char requestBuffer[ROOMEVENT_REQUEST_SIZE];
-    sprintf(requestBuffer,
+    STATIC char requestBuffer[ROOM_SEND_REQUEST_SIZE];
+    snprintf(requestBuffer, ROOM_SEND_REQUEST_SIZE,
         "{"
         "\"type\":\"%s\","
         "\"content\":%s,"
@@ -620,21 +835,24 @@ MatrixClientSendEventEncrypted(
 
     // get megolm session
     MatrixMegolmOutSession * outSession;
-    MatrixClientGetMegolmOutSession(client, roomId, &outSession);
+    if (! MatrixClientGetMegolmOutSession(client, roomId, &outSession))
+        MatrixClientNewMegolmOutSession(client, roomId, &outSession);
         
     // encrypt
-    static char encryptedBuffer[ENCRYPTED_REQUEST_SIZE];
     MatrixMegolmOutSessionEncrypt(outSession,
         requestBuffer,
-        encryptedBuffer, ENCRYPTED_REQUEST_SIZE);
+        g_EncryptedRequestBuffer, ENCRYPTED_REQUEST_SIZE);
+
+    char thisDeviceKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);
+    
 
     // encrypted event json
-    const char * senderKey = client->deviceKey;
+    const char * senderKey = thisDeviceKey;
     const char * sessionId = outSession->id;
     const char * deviceId = client->deviceId;
 
-    static char encryptedEventBuffer[ENCRYPTED_EVENT_SIZE];
-    sprintf(encryptedEventBuffer,
+    snprintf(g_EncryptedEventBuffer, ENCRYPTED_EVENT_SIZE,
         "{"
         "\"algorithm\":\"m.megolm.v1.aes-sha2\","
         "\"ciphertext\":\"%s\","
@@ -642,7 +860,7 @@ MatrixClientSendEventEncrypted(
         "\"sender_key\":\"%s\","
         "\"session_id\":\"%s\""
         "}",
-        encryptedBuffer,
+        g_EncryptedRequestBuffer,
         deviceId,
         senderKey,
         sessionId);
@@ -651,72 +869,535 @@ MatrixClientSendEventEncrypted(
     return MatrixClientSendEvent(client,
         roomId,
         "m.room.encrypted",
-        encryptedEventBuffer);
+        g_EncryptedEventBuffer);
+}
+
+// this handles to_device events received from a sync
+// mainly for verification (m.key.verification.* events)
+void
+MatrixClientHandleEvent(
+    MatrixClient * client,
+    const char * event, int eventLen
+) {
+    // get the event type
+    STATIC char eventType[128];
+    memset(eventType, 0, sizeof(eventType));
+    mjson_get_string(event, eventLen, "$.type", eventType, 128);
+
+    // static variables for verification
+    // since verification takes multiple requests
+    // data is cleared when verification is finished or started
+    static char transactionId[64];
+    static char verifyFromDeviceId[DEVICE_ID_SIZE];
+    static OlmSAS * olmSas = NULL;
+
+    // initial verification request, reply that we are ready to verify
+    if (strcmp(eventType, "m.key.verification.request") == 0) {
+        // reset static data
+        memset(transactionId, 0, 64);
+        memset(verifyFromDeviceId, 0, DEVICE_ID_SIZE);
+        if (olmSas != NULL)
+            free(olmSas);
+        
+        mjson_get_string(event, eventLen, "$.content.transaction_id", transactionId, 64);
+        mjson_get_string(event, eventLen, "$.content.from_device", verifyFromDeviceId, DEVICE_ID_SIZE);
+        
+        char verificationReadyBuffer[2048];
+        snprintf(verificationReadyBuffer, 2048,
+            "{"
+            "\"from_device\":\"%s\","
+            "\"methods\":[\"m.sas.v1\"],"
+            "\"transaction_id\":\"%s\""
+            "}",
+            client->deviceId,
+            transactionId);
+        
+        MatrixClientSendToDevice(client,
+            client->userId,
+            verifyFromDeviceId,
+            verificationReadyBuffer,
+            "m.key.verification.ready");
+    }
+    else if (strcmp(eventType, "m.key.verification.start") == 0) {
+        olmSas = olm_sas(malloc(olm_sas_size()));
+        void * sasRandomBytes = malloc(olm_create_sas_random_length(olmSas));
+        olm_create_sas(olmSas,
+            sasRandomBytes,
+            olm_create_sas_random_length(olmSas));
+        
+        OlmUtility * olmUtil = olm_utility(malloc(olm_utility_size()));
+        
+        // calculate commitment according to 
+        // https://spec.matrix.org/v1.8/client-server-api/#mkeyverificationaccept
+        STATIC char publicKey[64];
+        STATIC char keyStartJsonCanonical[512];
+        STATIC char concat[512+64];
+        STATIC char commitment[1024];
+        olm_sas_get_pubkey(olmSas,
+            publicKey,
+            64);
+
+        const char * keyStartJson;
+        int keyStartJsonLen;
+        mjson_find(event, eventLen, "$.content", &keyStartJson, &keyStartJsonLen);
+        JsonCanonicalize(keyStartJson, keyStartJsonLen, keyStartJsonCanonical, 512);
+
+        int concatLen =
+            snprintf(concat, 512+64, "%.*s%s", (int)olm_sas_pubkey_length(olmSas), publicKey, keyStartJsonCanonical);
+
+        int commitmentLen =
+            olm_sha256(olmUtil, concat, concatLen, commitment, 1024);
+        olm_clear_utility(olmUtil);
+        free(olmUtil);
+        
+        STATIC char verificationAcceptBuffer[512];
+        snprintf(verificationAcceptBuffer, 512,
+            "{"
+            "\"commitment\":\"%.*s\","
+            "\"hash\":\"sha256\","
+            "\"key_agreement_protocol\":\"curve25519\","
+            "\"message_authentication_code\":\"hkdf-hmac-sha256.v2\","
+            "\"method\":\"m.sas.v1\","
+            "\"short_authentication_string\":[\"decimal\"],"
+            "\"transaction_id\":\"%s\""
+            "}",
+            commitmentLen, commitment,
+            transactionId);
+        
+        MatrixClientSendToDevice(client,
+            client->userId,
+            verifyFromDeviceId,
+            verificationAcceptBuffer,
+            "m.key.verification.accept");
+    }
+    // send our sas key and calculate sas using their received key
+    else if (strcmp(eventType, "m.key.verification.key") == 0) {
+        STATIC char publicKey[128];
+        olm_sas_get_pubkey(olmSas,
+            publicKey,
+            128);
+
+        STATIC char theirPublicKey[128];
+        int theirPublicKeyLen =
+            mjson_get_string(event, eventLen, "$.content.key", theirPublicKey, 128);
+
+        olm_sas_set_their_key(olmSas, theirPublicKey, theirPublicKeyLen);
+        
+        STATIC char verificationKeyBuffer[256];
+        snprintf(verificationKeyBuffer, 256,
+            "{"
+            "\"key\":\"%.*s\","
+            "\"transaction_id\":\"%s\""
+            "}",
+            (int)olm_sas_pubkey_length(olmSas), publicKey,
+            transactionId);
+        
+        MatrixClientSendToDevice(client,
+            client->userId,
+            verifyFromDeviceId,
+            verificationKeyBuffer,
+            "m.key.verification.key");
+        
+        // sas
+        STATIC char hkdfInfo[1024];
+        int hkdfInfoLen =
+            snprintf(hkdfInfo, 1024,
+                "MATRIX_KEY_VERIFICATION_SAS%s%s%s%s%s",
+                client->userId,
+                verifyFromDeviceId,
+                client->userId,
+                client->deviceId,
+                transactionId);
+
+        unsigned char sasBytes[5];
+        olm_sas_generate_bytes(olmSas,
+            hkdfInfo, hkdfInfoLen,
+            sasBytes, 5);
+        int b0 = sasBytes[0];
+        int b1 = sasBytes[1];
+        int b2 = sasBytes[2];
+        int b3 = sasBytes[3];
+        int b4 = sasBytes[4];
+
+        // for now just printf SAS numbers
+        // https://spec.matrix.org/v1.8/client-server-api/#sas-method-decimal
+        printf("%d | %d | %d\n",
+            ((b0 << 5) | (b1 >> 3)) + 1000,
+            (((b1 & 0x7) << 10) | (b2 << 2) | (b3 >> 6)) + 1000,
+            (((b3 & 0x3F) << 7) | (b4 >> 1)) + 1000);
+    }
+    // calculate MACs for signing key, master key and the key list
+    else if (strcmp(eventType, "m.key.verification.mac") == 0) {        
+        // mac
+        STATIC char masterKey[123];
+        MatrixClientRequestMasterKey(client, masterKey, 123);
+
+        STATIC char keyList[256];
+        STATIC char keyListMac[256];
+        STATIC char key1Id[128];
+        STATIC char key1[128];
+        STATIC char key1Mac[128];
+        STATIC char key2Id[128];
+        STATIC char key2[128];
+        STATIC char key2Mac[128];
+
+        // keys have to be sorted so write keys/key IDs into key1/key2
+        // depending on lexicographical order
+        if (strcmp(masterKey, client->deviceId) < 0) {
+            snprintf(key1Id, 1024, "ed25519:%s", masterKey);
+            strcpy(key1, masterKey);
+            snprintf(key2Id, 1024, "ed25519:%s", client->deviceId);
+            MatrixOlmAccountGetSigningKey(&client->olmAccount, key2, 1024);
+        }
+        else {
+            snprintf(key1Id, 1024, "ed25519:%s", client->deviceId);
+            MatrixOlmAccountGetSigningKey(&client->olmAccount, key1, 1024);
+            snprintf(key2Id, 1024, "ed25519:%s", masterKey);
+            strcpy(key2, masterKey);
+        }
+
+        // create key list
+        snprintf(keyList, 1024,
+            "%s,%s", key1Id, key2Id);
+        
+        // generate MAC info for both keys and key list
+        // https://spec.matrix.org/v1.8/client-server-api/#mac-calculation
+        STATIC char macInfo[1024];
+        int macInfoLen;
+        {
+            macInfoLen =
+                snprintf(macInfo, 1024,
+                    "MATRIX_KEY_VERIFICATION_MAC%s%s%s%s%s%s",
+                    client->userId,
+                    client->deviceId,
+                    client->userId,
+                    verifyFromDeviceId,
+                    transactionId,
+                    "KEY_IDS");
+            olm_sas_calculate_mac_fixed_base64(olmSas, keyList, strlen(keyList), macInfo, macInfoLen, keyListMac, 1024);
+        }
+        {
+            macInfoLen =
+                snprintf(macInfo, 1024,
+                    "MATRIX_KEY_VERIFICATION_MAC%s%s%s%s%s%s",
+                    client->userId,
+                    client->deviceId,
+                    client->userId,
+                    verifyFromDeviceId,
+                    transactionId,
+                    key1Id);
+            olm_sas_calculate_mac_fixed_base64(olmSas, key1, strlen(key1), macInfo, macInfoLen, key1Mac, 1024);
+        }
+        {
+            macInfoLen =
+                snprintf(macInfo, 1024,
+                    "MATRIX_KEY_VERIFICATION_MAC%s%s%s%s%s%s",
+                    client->userId,
+                    client->deviceId,
+                    client->userId,
+                    verifyFromDeviceId,
+                    transactionId,
+                    key2Id);
+            olm_sas_calculate_mac_fixed_base64(olmSas, key2, strlen(key2), macInfo, macInfoLen, key2Mac, 1024);
+        }
+
+        // construct message and send
+        STATIC char verificationMacBuffer[1024];
+        snprintf(verificationMacBuffer, 1024,
+            "{"
+            "\"keys\":\"%s\","
+            "\"mac\":{"
+            "\"%s\":\"%s\","
+            "\"%s\":\"%s\""
+            "},"
+            "\"transaction_id\":\"%s\""
+            "}",
+            keyListMac,
+            key1Id,
+            key1Mac,
+            key2Id,
+            key2Mac,
+            transactionId);
+        
+        MatrixClientSendToDevice(client,
+            client->userId,
+            verifyFromDeviceId,
+            verificationMacBuffer,
+            "m.key.verification.mac");
+
+        // send 'done' message
+        STATIC char verificationDoneBuffer[128];
+        snprintf(verificationDoneBuffer, 128,
+            "{"
+            "\"transaction_id\":\"%s\""
+            "}",
+            transactionId);
+        
+        MatrixClientSendToDevice(client,
+            client->userId,
+            verifyFromDeviceId,
+            verificationDoneBuffer,
+            "m.key.verification.done");
+        
+        free(olmSas);
+
+        client->verified = true;
+    }
+    else if (strcmp(eventType, "m.room.encrypted") == 0) {
+        STATIC char algorithm[128];
+        mjson_get_string(event, eventLen, "$.content.algorithm", algorithm, 128);
+
+        // since this only handles to_device messages algorithm should always be olm
+        if (strcmp(algorithm, "m.olm.v1.curve25519-aes-sha2") == 0) {
+            STATIC char thisDeviceKey[DEVICE_KEY_SIZE];
+            MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);
+
+            STATIC char jp[128];
+            snprintf(jp, 128, "$.content.ciphertext.%s.type", thisDeviceKey);
+
+            double messageType;
+            mjson_get_number(event, eventLen, jp, &messageType);
+            int messageTypeInt = (int)messageType;
+
+            snprintf(jp, 128, "$.content.ciphertext.%s.body", thisDeviceKey);
+
+            mjson_get_string(event, eventLen, jp, g_EncryptedEventBuffer, 2048);
+
+            MatrixOlmSession * olmSession;
+            
+            // depending on message type create new incoming
+            // (type 0 indicates a new session so we dont check locally)
+            if (messageTypeInt == 0) {
+                MatrixClientNewOlmSessionIn(client,
+                    client->userId,
+                    verifyFromDeviceId,
+                    g_EncryptedEventBuffer,
+                    &olmSession);
+            }
+            // or new outgoing, checking for known sessions first
+            else {
+                if (! MatrixClientGetOlmSession(client, client->userId, verifyFromDeviceId, &olmSession))
+                {
+                    MatrixClientNewOlmSessionOut(client,
+                        client->userId,
+                        verifyFromDeviceId,
+                        &olmSession);
+                }
+            }
+            
+            STATIC char decrypted[2048];
+            MatrixOlmSessionDecrypt(olmSession,
+                messageTypeInt, g_EncryptedEventBuffer, decrypted, 2048);
+            
+            MatrixClientHandleEvent(client, decrypted, strlen(decrypted));
+        }
+    }
+    else if (strcmp(eventType, "m.room_key") == 0 ||
+             strcmp(eventType, "m.forwarded_room_key") == 0) {
+        // store session information
+        STATIC char roomId[128];
+        STATIC char sessionId[128];
+        STATIC char sessionKey[1024];
+        mjson_get_string(event, eventLen, "$.content.room_id", roomId, 128);
+        mjson_get_string(event, eventLen, "$.content.session_id", sessionId, 128);
+        mjson_get_string(event, eventLen, "$.content.session_key", sessionKey, 1024);
+
+        MatrixMegolmInSession * megolmInSession;
+        MatrixClientNewMegolmInSession(client, roomId, sessionId, sessionKey, &megolmInSession);
+    }
+}
+
+void
+MatrixClientHandleRoomEvent(
+    MatrixClient * client,
+    const char * room, int roomLen,
+    const char * event, int eventLen)
+{
+    STATIC char eventType[128];
+    memset(eventType, 0, sizeof(eventType));
+    mjson_get_string(event, eventLen, "$.type", eventType, 128);
+
+    if (strcmp(eventType, "m.room.encrypted") == 0) {
+        STATIC char algorithm[128];
+        mjson_get_string(event, eventLen, "$.content.algorithm", algorithm, 128);
+
+        // only room specific message type is encrypted
+        // since this is only room messages, algorithm should always be megolm
+        if (strcmp(algorithm, "m.megolm.v1.aes-sha2") == 0) {
+            STATIC char sessionId[128];
+            int sessionIdLen =
+                mjson_get_string(event, eventLen, "$.content.session_id", sessionId, 128);
+
+            bool res;
+
+            MatrixMegolmInSession * megolmInSession;
+            res = MatrixClientGetMegolmInSession(client,
+                room, roomLen,
+                sessionId, sessionIdLen,
+                &megolmInSession);
+
+            if (res) {
+                mjson_get_string(event, eventLen, "$.content.ciphertext", g_EncryptedEventBuffer, 2048);
+
+                STATIC char decrypted[2048];
+                MatrixMegolmInSessionDecrypt(megolmInSession, g_EncryptedEventBuffer, strlen(g_EncryptedEventBuffer), decrypted, 2048);
+
+                MatrixClientHandleEvent(client, decrypted, strlen(decrypted));
+            }
+            else {
+                printf("error: megolm session not known\n");
+            }
+        }
+    }
+    MatrixClientHandleEvent(client, event, eventLen);
+}
+
+// pass the response from sync to Handle(Room)Event
+void
+MatrixClientHandleSync(
+    MatrixClient * client,
+    char * syncBuffer, int syncBufferLen,
+    char * nextBatch, int nextBatchCap)
+{    
+    int res;
+
+    const char * s = syncBuffer;
+    int slen = syncBufferLen;
+
+    // read next_batch
+    mjson_get_string(s, slen, "$.next_batch", nextBatch, nextBatchCap);
+
+    // to_device
+    const char * events;
+    int eventsLen;
+    res =
+        mjson_find(s, slen, "$.to_device.events", &events, &eventsLen);
+    
+    // iterate event and pass to HandleEvent
+    if (res != MJSON_TOK_INVALID) {
+        {
+        int koff, klen, voff, vlen, vtype, off = 0;
+        for (off = 0; (off = mjson_next(events, eventsLen, off, &koff, &klen,
+                                        &voff, &vlen, &vtype)) != 0; ) {
+            const char * v = events + voff;
+
+            MatrixClientHandleEvent(client, v, vlen);
+        }
+        }
+    }
+
+    // rooms
+    const char * rooms;
+    int roomsLen;
+    res =
+        mjson_find(s, slen, "$.rooms.join", &rooms, &roomsLen);
+    
+    if (res != MJSON_TOK_INVALID) {
+        // iterate rooms
+        int koff, klen, voff, vlen, vtype, off = 0;
+        for (off = 0; (off = mjson_next(rooms, roomsLen, off, &koff, &klen,
+                                        &voff, &vlen, &vtype)) != 0; ) {
+            const char * k = rooms + koff;
+            const char * v = rooms + voff;
+
+            const char * events;
+            int eventsLen;
+            res =
+                mjson_find(v, vlen, "$.timeline.events", &events, &eventsLen);
+            
+            if (res != MJSON_TOK_INVALID) {
+                // iterate messages in that room
+                int koff2, klen2, voff2, vlen2, vtype2, off2 = 0;
+                for (off2 = 0; (off2 = mjson_next(events, eventsLen, off2, &koff2, &klen2,
+                                                &voff2, &vlen2, &vtype2)) != 0; ) {
+                    const char * v2 = events + voff2;
+
+                    MatrixClientHandleRoomEvent(client,
+                        k+1, klen-2,
+                        v2, vlen2);
+                }
+            }
+        }
+    }
 }
 
-// https://spec.matrix.org/v1.6/client-server-api/#get_matrixclientv3sync
+// https://spec.matrix.org/v1.8/client-server-api/#get_matrixclientv3sync
 bool
 MatrixClientSync(
     MatrixClient * client,
-    char * outSyncBuffer, int outSyncCap)
+    char * outSyncBuffer, int outSyncCap,
+    char * nextBatch, int nextBatchCap)
 {
-    return
-        MatrixHttpGet(client,
-            "/_matrix/client/v3/sync",
+    // filter={\"event_fields\":[\"to_device\"]}
+    STATIC char url[MAX_URL_LEN];
+    snprintf(url, MAX_URL_LEN,
+        "/_matrix/client/v3/sync?timeout=%d" "%s" "%s",
+        SYNC_TIMEOUT,
+        "",
+        // "&filter={\"event_fields\":[\"to_device\"]}",
+        strlen(nextBatch) > 0 ? "&since=" : "");
+    
+    int index = strlen(url);
+
+    // URL encode next_batch parameter since it can include ~
+    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';
+
+    bool result =
+        MatrixHttpGet(client->hc,
+            url,
             outSyncBuffer, outSyncCap,
             true);
+    
+    MatrixClientHandleSync(client,
+        outSyncBuffer, strlen(outSyncBuffer),
+        nextBatch, nextBatchCap);
+    
+    return result;
 }
 
+// https://spec.matrix.org/v1.8/client-server-api/#get_matrixclientv3roomsroomideventeventid
 bool
-MatrixClientShareMegolmOutSession(
+MatrixClientGetRoomEvent(
     MatrixClient * client,
-    const char * userId,
-    const char * deviceId,
-    MatrixMegolmOutSession * session)
+    const char * roomId,
+    const char * eventId,
+    char * outEvent, int outEventCap)
 {
-    // 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
-    );
-
-    // // get olm session
-    // MatrixOlmSession * olmSession;
-    // MatrixClientGetOlmSession(client, userId, deviceId, &olmSession);
-
-    // // encrypt
-    // char encryptedBuffer[KEY_SHARE_EVENT_LEN];
-    // MatrixOlmSessionEncrypt(olmSession,
-    //     eventBuffer,
-    //     encryptedBuffer, KEY_SHARE_EVENT_LEN);
-
-    // send
-    MatrixClientSendToDeviceEncrypted(client,
-        userId,
-        deviceId,
-        eventBuffer,
-        "m.room_key");
+    STATIC char url[MAX_URL_LEN];
+    snprintf(url, MAX_URL_LEN,
+        "/_matrix/client/v3/rooms/%s/event/%s",
+            roomId,
+            eventId);
 
-    return true;
+    return
+        MatrixHttpGet(client->hc,
+            url,
+            outEvent, outEventCap,
+            true);
 }
 
 bool
-MatrixClientShareMegolmOutSessionTest(
+MatrixClientShareMegolmOutSession(
     MatrixClient * client,
+    const char * userId,
     const char * deviceId,
     MatrixMegolmOutSession * session)
 {
     // generate room key event
-    char eventBuffer[KEY_SHARE_EVENT_LEN];
-    sprintf(eventBuffer,
+    STATIC char eventBuffer[KEY_SHARE_EVENT_LEN];
+    snprintf(eventBuffer, KEY_SHARE_EVENT_LEN,
         "{"
             "\"algorithm\":\"m.megolm.v1.aes-sha2\","
             "\"room_id\":\"%s\","
@@ -729,8 +1410,8 @@ MatrixClientShareMegolmOutSessionTest(
     );
 
     // send
-    MatrixClientSendToDevice(client,
-        client->userId,
+    MatrixClientSendToDeviceEncrypted(client,
+        userId,
         deviceId,
         eventBuffer,
         "m.room_key");
@@ -738,23 +1419,6 @@ MatrixClientShareMegolmOutSessionTest(
     return true;
 }
 
-// bool
-// MatrixClientSetMegolmOutSession(
-//     MatrixClient * client,
-//     const char * roomId,
-//     MatrixMegolmOutSession session)
-// {
-//     if (client->numMegolmOutSessions < 10)
-//     {
-//         session.roomId = roomId;
-//         client->megolmOutSessions[client->numMegolmOutSessions] = session;
-//         client->numMegolmOutSessions++;
-
-//         return true;
-//     }
-//     return false;
-// }
-
 bool
 MatrixClientGetMegolmOutSession(
     MatrixClient * client,
@@ -770,14 +1434,25 @@ MatrixClientGetMegolmOutSession(
         }
     }
 
+    return false;
+}
+
+bool
+MatrixClientNewMegolmOutSession(
+    MatrixClient * client,
+    const char * roomId,
+    MatrixMegolmOutSession ** outSession)
+{
     if (client->numMegolmOutSessions < NUM_MEGOLM_SESSIONS)
     {
-        MatrixMegolmOutSessionInit(
-            &client->megolmOutSessions[client->numMegolmOutSessions],
+        MatrixMegolmOutSession * result =
+            &client->megolmOutSessions[client->numMegolmOutSessions];
+        
+        MatrixMegolmOutSessionInit(result,
             roomId);
 
-        *outSession = &client->megolmOutSessions[client->numMegolmOutSessions];
-        
+        *outSession = result;
+
         client->numMegolmOutSessions++;
 
         return true;
@@ -786,6 +1461,95 @@ MatrixClientGetMegolmOutSession(
     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
 MatrixClientGetOlmSession(
     MatrixClient * client,
@@ -793,6 +1557,8 @@ MatrixClientGetOlmSession(
     const char * deviceId,
     MatrixOlmSession ** outSession)
 {
+    (void)userId; //unused for now
+
     for (int i = 0; i < client->numOlmSessions; i++)
     {
         if (strcmp(client->olmSessions[i].deviceId, deviceId) == 0)
@@ -802,10 +1568,54 @@ MatrixClientGetOlmSession(
         }
     }
 
+    return false;
+}
+
+bool
+MatrixClientNewOlmSessionIn(
+    MatrixClient * client,
+    const char * userId,
+    const char * deviceId,
+    const char * encrypted,
+    MatrixOlmSession ** outSession)
+{
+    (void)userId; //unused for now
+    
     if (client->numOlmSessions < NUM_OLM_SESSIONS)
     {
-        static char deviceKey[DEVICE_KEY_SIZE];
-        MatrixClientGetDeviceKey(client,
+        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
+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);
 
@@ -832,7 +1642,7 @@ MatrixClientGetOlmSession(
     return false;
 }
 
-// https://spec.matrix.org/v1.6/client-server-api/#put_matrixclientv3sendtodeviceeventtypetxnid
+// https://spec.matrix.org/v1.8/client-server-api/#put_matrixclientv3sendtodeviceeventtypetxnid
 bool
 MatrixClientSendToDevice(
     MatrixClient * client,
@@ -841,15 +1651,14 @@ MatrixClientSendToDevice(
     const char * message,
     const char * msgType)
 {
-    static char requestUrl[MAX_URL_LEN];
-    sprintf(requestUrl,
+    STATIC char requestUrl[MAX_URL_LEN];
+    snprintf(requestUrl, MAX_URL_LEN,
         TODEVICE_URL, msgType, (int)time(NULL));
 
-    static char eventBuffer[TODEVICE_EVENT_SIZE];
-    snprintf(eventBuffer, TODEVICE_EVENT_SIZE,
+    snprintf(g_TodeviceEventBuffer, TODEVICE_EVENT_SIZE,
         "{"
-            "\"messages\": {"
-                "\"%s\": {"
+            "\"messages\":{"
+                "\"%s\":{"
                     "\"%s\":%s"
                 "}"
             "}"
@@ -858,12 +1667,12 @@ MatrixClientSendToDevice(
         deviceId,
         message);
 
-    static char responseBuffer[ROOMEVENT_RESPONSE_SIZE];
+    STATIC char responseBuffer[ROOM_SEND_RESPONSE_SIZE];
     bool result =
-        MatrixHttpPut(client,
+        MatrixHttpPut(client->hc,
             requestUrl,
-            eventBuffer,
-            responseBuffer, ROOMEVENT_RESPONSE_SIZE,
+            g_TodeviceEventBuffer,
+            responseBuffer, ROOM_SEND_RESPONSE_SIZE,
             true);
     
     return result;
@@ -879,41 +1688,47 @@ MatrixClientSendToDeviceEncrypted(
 {
     // get olm session
     MatrixOlmSession * olmSession;
-    MatrixClientGetOlmSession(client, userId, deviceId, &olmSession);
+    if (! MatrixClientGetOlmSession(client, userId, deviceId, &olmSession))
+        MatrixClientNewOlmSessionOut(client, userId, deviceId, &olmSession);
 
     // create event json
-    char deviceKey[DEVICE_KEY_SIZE];
-    MatrixClientGetDeviceKey(client, deviceId, deviceKey, DEVICE_KEY_SIZE);
+    char targetDeviceKey[DEVICE_KEY_SIZE];
+    MatrixClientRequestDeviceKey(client, deviceId, targetDeviceKey, DEVICE_KEY_SIZE);
+    char targetSigningKey[SIGNING_KEY_SIZE];
+    MatrixClientRequestSigningKey(client, deviceId, targetSigningKey, SIGNING_KEY_SIZE);
     
-    static char eventBuffer[TODEVICE_EVENT_SIZE];
-    sprintf(eventBuffer,
+    char thisSigningKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetSigningKey(&client->olmAccount, thisSigningKey, DEVICE_KEY_SIZE);
+
+    snprintf(g_TodeviceEventBuffer, TODEVICE_EVENT_SIZE,
         "{"
-        "\"type\": \"%s\","
-        "\"content\": \"%s\","
-        "\"sender\": \"%s\","
-        "\"recipient\": \"%s\","
-        "\"recipient_keys\": {"
-          "\"ed25519\": \"%s\""
+        "\"type\":\"%s\","
+        "\"content\":%s,"
+        "\"sender\":\"%s\","
+        "\"recipient\":\"%s\","
+        "\"recipient_keys\":{"
+        "\"ed25519\":\"%s\""
         "},"
-        "\"keys\": {"
-          "\"ed25519\": \"%s\""
+        "\"keys\":{"
+        "\"ed25519\":\"%s\""
         "}"
         "}",
         msgType,
         message,
         client->userId,
         userId, // recipient user id
-        deviceKey, // recipient device key
-        client->deviceKey);
+        targetSigningKey, // recipient device key
+        thisSigningKey);
 
     // encrypt
-    static char encryptedBuffer[ENCRYPTED_REQUEST_SIZE];
     MatrixOlmSessionEncrypt(olmSession,
-        eventBuffer,
-        encryptedBuffer, ENCRYPTED_REQUEST_SIZE);
+        g_TodeviceEventBuffer,
+        g_EncryptedRequestBuffer, ENCRYPTED_REQUEST_SIZE);
+
+    char thisDeviceKey[DEVICE_KEY_SIZE];
+    MatrixOlmAccountGetDeviceKey(&client->olmAccount, thisDeviceKey, DEVICE_KEY_SIZE);
 
-    static char encryptedEventBuffer[ENCRYPTED_EVENT_SIZE];
-    sprintf(encryptedEventBuffer,
+    snprintf(g_EncryptedEventBuffer, ENCRYPTED_EVENT_SIZE,
         "{"
         "\"algorithm\":\"m.olm.v1.curve25519-aes-sha2\","
         "\"ciphertext\":{"
@@ -925,27 +1740,51 @@ MatrixClientSendToDeviceEncrypted(
         "\"device_id\":\"%s\","
         "\"sender_key\":\"%s\""
         "}",
-        deviceKey,
-        encryptedBuffer,
-        0, //olmSession->type,
+        targetDeviceKey,
+        // olm_encrypt_message_length(olmSession->session, strlen(g_TodeviceEventBuffer)), g_EncryptedRequestBuffer,
+        g_EncryptedRequestBuffer,
+        olm_session_has_received_message(olmSession->session),
         client->deviceId,
-        client->deviceKey);
+        thisDeviceKey);
 
     // send
     return MatrixClientSendToDevice(
         client,
         userId,
         deviceId,
-        encryptedEventBuffer,
+        g_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)
 {
+    for (int i = 0; i < client->numDevices; i++)
+    {
+        if (strcmp(client->devices[i].deviceId, deviceId) == 0)
+        {
+            *outDevice = &client->devices[i];
+            return true;
+        }
+    }
+
     MatrixClientRequestDeviceKeys(client);
 
     for (int i = 0; i < client->numDevices; i++)
@@ -962,7 +1801,7 @@ MatrixClientFindDevice(
 }
 
 bool
-MatrixClientGetDeviceKey(
+MatrixClientRequestDeviceKey(
     MatrixClient * client,
     const char * deviceId,
     char * outDeviceKey, int outDeviceKeyCap)
@@ -986,21 +1825,73 @@ MatrixClientGetDeviceKey(
     return false;
 }
 
-// https://spec.matrix.org/v1.6/client-server-api/#post_matrixclientv3keysquery
+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;
+}
+
+bool
+MatrixClientRequestMasterKey(
+    MatrixClient * client,
+    char * outMasterKey, int outMasterKeyCap)
+{
+    if (strlen(client->masterKey) > 0) {
+        strncpy(outMasterKey, client->masterKey, outMasterKeyCap);
+        return true;
+    }
+
+    MatrixClientRequestDeviceKeys(client);
+    
+    if (strlen(client->masterKey) > 0) {
+        strncpy(outMasterKey, client->masterKey, outMasterKeyCap);
+        return true;
+    }
+
+    return false;
+}
+
+// https://spec.matrix.org/v1.8/client-server-api/#post_matrixclientv3keysquery
 bool
 MatrixClientRequestDeviceKeys(
     MatrixClient * client)
 {
-    static char userIdEscaped[USER_ID_SIZE];
+    if (client->numDevices >= NUM_DEVICES) {
+        printf("error: Maximum number of devices reached\n");
+        return false;
+    }
+
+    // escape userId so we can use it in json queries
+    STATIC char userIdEscaped[USER_ID_SIZE];
     JsonEscape(client->userId, strlen(client->userId),
         userIdEscaped, USER_ID_SIZE);
 
-    static char request[KEYS_QUERY_REQUEST_SIZE];
+    // construct and send request
+    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,
+    STATIC char responseBuffer[KEYS_QUERY_RESPONSE_SIZE];
+    bool requestResult = MatrixHttpPost(client->hc,
         KEYS_QUERY_URL,
         request,
         responseBuffer, KEYS_QUERY_RESPONSE_SIZE,
@@ -1010,18 +1901,32 @@ MatrixClientRequestDeviceKeys(
         return false;
 
     // query for retrieving device keys for user id
-    static char query[JSON_QUERY_SIZE];
-    snprintf(query, JSON_QUERY_SIZE,
-        "$.device_keys.%s", userIdEscaped);
-    
+    STATIC char query[JSON_QUERY_SIZE];
     const char * s;
     int slen;
+
+    // look for master key
+    snprintf(query, JSON_QUERY_SIZE,
+        "$.master_keys.%s.keys", userIdEscaped);
     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; ) {
+        snprintf(client->masterKey, MASTER_KEY_SIZE,
+            "%.*s", vlen-2, s+voff+1);
+    }
+
+    // iterate over returned devices for that userId
+    snprintf(query, JSON_QUERY_SIZE,
+        "$.device_keys.%s", userIdEscaped);
+    
+    mjson_find(responseBuffer, strlen(responseBuffer),
+        query, &s, &slen);
+    
+    // loop over keys
+    // creating a new device if possible
     for (off = 0; (off = mjson_next(s, slen, off, &koff, &klen,
                                     &voff, &vlen, &vtype)) != 0; ) {
         const char * key = s + koff;
@@ -1033,17 +1938,31 @@ MatrixClientRequestDeviceKeys(
             "%.*s", klen-2, key+1);
 
         // look for device key in value
-        static char deviceKeyQuery[JSON_QUERY_SIZE];
+        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)
         {
-            client->devices[client->numDevices] = d;
-            client->numDevices++;
+            bool foundDevice = false;
+            for (int i = 0; i < client->numDevices; i++)
+                if (strcmp(client->devices[i].deviceId, d.deviceId) == 0)
+                    foundDevice = true;
+
+            if (! foundDevice) {
+                client->devices[client->numDevices] = d;
+                client->numDevices++;
+            }
         }
         else
         {
@@ -1053,3 +1972,17 @@ MatrixClientRequestDeviceKeys(
 
     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;
+}