Add HTTP GET APIs for creating, removing users and giving control

common/network/GetAPI.h

@@ -19,6 +19,7 @@
 #ifndef __NETWORK_GET_API_H__
 #define __NETWORK_GET_API_H__
 
+#include <kasmpasswd.h>
 #include <pthread.h>
 #include <rfb/PixelBuffer.h>
 #include <rfb/PixelFormat.h>
@@ -29,7 +30,7 @@ namespace network {
 
   class GetAPIMessager {
   public:
-    GetAPIMessager();
+    GetAPIMessager(const char *passwdfile_);
 
     // from main thread
     void mainUpdateScreen(rfb::PixelBuffer *pb);
@@ -38,7 +39,27 @@ namespace network {
     uint8_t *netGetScreenshot(uint16_t w, uint16_t h,
                               const uint8_t q, const bool dedup,
                               uint32_t &len, uint8_t *staging);
+    uint8_t netAddUser(const char name[], const char pw[], const bool write);
+    uint8_t netRemoveUser(const char name[]);
+    uint8_t netGiveControlTo(const char name[]);
+
+    enum USER_ACTION {
+      //USER_ADD, - handled locally for interactivity
+      USER_REMOVE,
+      USER_GIVE_CONTROL,
+    };
+
+    struct action_data {
+      enum USER_ACTION action;
+      kasmpasswd_entry_t data;
+    };
+
+    pthread_mutex_t userMutex;
+    std::vector<action_data> actionQueue;
+
   private:
+    const char *passwdfile;
+
     pthread_mutex_t screenMutex;
     rfb::ManagedPixelBuffer screenPb;
     uint16_t screenW, screenH;

common/network/GetAPIMessager.cxx

@@ -53,10 +53,12 @@ static const struct TightJPEGConfiguration conf[10] = {
   { 100, subsampleNone }  // 9
 };
 
-GetAPIMessager::GetAPIMessager(): screenW(0), screenH(0), screenHash(0),
+GetAPIMessager::GetAPIMessager(const char *passwdfile_): passwdfile(passwdfile_),
+					screenW(0), screenH(0), screenHash(0),
 					cachedW(0), cachedH(0), cachedQ(0) {
 
 	pthread_mutex_init(&screenMutex, NULL);
+	pthread_mutex_init(&userMutex, NULL);
 }
 
 // from main thread
@@ -181,3 +183,102 @@ uint8_t *GetAPIMessager::netGetScreenshot(uint16_t w, uint16_t h,
 
 	return ret;
 }
+
+#define USERNAME_LEN sizeof(((struct kasmpasswd_entry_t *)0)->user)
+#define PASSWORD_LEN sizeof(((struct kasmpasswd_entry_t *)0)->password)
+
+uint8_t GetAPIMessager::netAddUser(const char name[], const char pw[], const bool write) {
+	if (strlen(name) >= USERNAME_LEN) {
+		vlog.error("Username too long");
+		return 0;
+	}
+
+	if (strlen(pw) >= PASSWORD_LEN) {
+		vlog.error("Password too long");
+		return 0;
+	}
+
+	if (!passwdfile)
+		return 0;
+
+	action_data act;
+
+	memcpy(act.data.user, name, USERNAME_LEN);
+	act.data.user[USERNAME_LEN - 1] = '\0';
+	memcpy(act.data.password, pw, PASSWORD_LEN);
+	act.data.password[PASSWORD_LEN - 1] = '\0';
+	act.data.owner = 0;
+	act.data.write = write;
+
+	if (pthread_mutex_lock(&userMutex))
+		return 0;
+
+        // This needs to be handled locally for proper interactivity
+        // (consider adding users when nobody is connected).
+        // The mutex and atomic rename keep things in sync.
+
+        struct kasmpasswd_t *set = readkasmpasswd(passwdfile);
+        unsigned s;
+        for (s = 0; s < set->num; s++) {
+          if (!strcmp(set->entries[s].user, act.data.user)) {
+            vlog.error("Can't create user %s, already exists", act.data.user);
+            goto out;
+          }
+        }
+
+        s = set->num++;
+        set->entries = (struct kasmpasswd_entry_t *) realloc(set->entries,
+                                                                 set->num * sizeof(struct kasmpasswd_entry_t));
+        set->entries[s] = act.data;
+
+        writekasmpasswd(passwdfile, set);
+        vlog.info("User %s created", act.data.user);
+out:
+	pthread_mutex_unlock(&userMutex);
+
+	return 1;
+}
+
+uint8_t GetAPIMessager::netRemoveUser(const char name[]) {
+	if (strlen(name) >= USERNAME_LEN) {
+		vlog.error("Username too long");
+		return 0;
+	}
+
+	action_data act;
+	act.action = USER_REMOVE;
+
+	memcpy(act.data.user, name, USERNAME_LEN);
+	act.data.user[USERNAME_LEN - 1] = '\0';
+
+	if (pthread_mutex_lock(&userMutex))
+		return 0;
+
+	actionQueue.push_back(act);
+
+	pthread_mutex_unlock(&userMutex);
+
+	return 1;
+}
+
+uint8_t GetAPIMessager::netGiveControlTo(const char name[]) {
+	if (strlen(name) >= USERNAME_LEN) {
+		vlog.error("Username too long");
+		return 0;
+	}
+
+	action_data act;
+	act.action = USER_GIVE_CONTROL;
+
+	memcpy(act.data.user, name, USERNAME_LEN);
+	act.data.user[USERNAME_LEN - 1] = '\0';
+
+	if (pthread_mutex_lock(&userMutex))
+		return 0;
+
+	actionQueue.push_back(act);
+
+	pthread_mutex_unlock(&userMutex);
+
+	return 1;
+}

common/network/TcpSocket.cxx

@@ -440,6 +440,25 @@ static uint8_t *screenshotCb(void *messager, uint16_t w, uint16_t h, const uint8
   return msgr->netGetScreenshot(w, h, q, dedup, *len, staging);
 }
 
+static uint8_t adduserCb(void *messager, const char name[], const char pw[],
+                          const uint8_t write)
+{
+  GetAPIMessager *msgr = (GetAPIMessager *) messager;
+  return msgr->netAddUser(name, pw, write);
+}
+
+static uint8_t removeCb(void *messager, const char name[])
+{
+  GetAPIMessager *msgr = (GetAPIMessager *) messager;
+  return msgr->netRemoveUser(name);
+}
+
+static uint8_t givecontrolCb(void *messager, const char name[])
+{
+  GetAPIMessager *msgr = (GetAPIMessager *) messager;
+  return msgr->netGiveControlTo(name);
+}
+
 WebsocketListener::WebsocketListener(const struct sockaddr *listenaddr,
                          socklen_t listenaddrlen,
                          bool sslonly, const char *cert, const char *certkey,
@@ -524,8 +543,11 @@ WebsocketListener::WebsocketListener(const struct sockaddr *listenaddr,
 
   settings.listen_sock = sock;
 
-  settings.messager = messager = new GetAPIMessager;
+  settings.messager = messager = new GetAPIMessager(settings.passwdfile);
   settings.screenshotCb = screenshotCb;
+  settings.adduserCb = adduserCb;
+  settings.removeCb = removeCb;
+  settings.givecontrolCb = givecontrolCb;
 
   pthread_t tid;
   pthread_create(&tid, NULL, start_server, NULL);

common/network/websocket.c

@@ -111,6 +111,29 @@ static const char *parse_get(const char * const in, const char * const opt, unsi
 	return "";
 }
 
+static void percent_decode(const char *src, char *dst) {
+	while (1) {
+		if (!*src)
+			break;
+		if (*src != '%') {
+			*dst++ = *src++;
+		} else {
+			src++;
+			if (!src[0] || !src[1])
+				break;
+			char hex[3];
+			hex[0] = src[0];
+			hex[1] = src[1];
+			hex[2] = '\0';
+
+			src += 2;
+			*dst++ = strtol(hex, NULL, 16);
+		}
+	}
+
+	*dst = '\0';
+}
+
 /*
  * SSL Wrapper Code
  */
@@ -842,7 +865,7 @@ nope:
 }
 
 static uint8_t ownerapi(ws_ctx_t *ws_ctx, const char *in) {
-    char buf[4096], path[4096], fullpath[4096], args[4096] = "";
+    char buf[4096], path[4096], args[4096] = "";
     uint8_t ret = 0; // 0 = continue checking
 
     if (strncmp(in, "GET ", 4)) {
@@ -871,7 +894,11 @@ static uint8_t ownerapi(ws_ctx_t *ws_ctx, const char *in) {
     memcpy(path, in, len);
     path[len] = '\0';
 
+    if (strstr(args, "password=")) {
+        wserr("Requested owner api '%s' with args (skipped, includes password)\n", path);
+    } else {
         wserr("Requested owner api '%s' with args '%s'\n", path, args);
+    }
 
     #define entry(x) if (!strcmp(path, x))
 
@@ -935,6 +962,112 @@ static uint8_t ownerapi(ws_ctx_t *ws_ctx, const char *in) {
             wserr("Invalid params to screenshot\n");
             goto nope;
         }
+    } else entry("/api/create_user") {
+        char decname[1024] = "", decpw[1024] = "";
+        uint8_t write = 0;
+
+        param = parse_get(args, "name", &len);
+        if (len) {
+            memcpy(buf, param, len);
+            buf[len] = '\0';
+            percent_decode(buf, decname);
+        }
+
+        param = parse_get(args, "password", &len);
+        if (len) {
+            memcpy(buf, param, len);
+            buf[len] = '\0';
+            percent_decode(buf, decpw);
+
+            struct crypt_data cdata;
+            cdata.initialized = 0;
+
+            const char *encrypted = crypt_r(decpw, "$5$kasm$", &cdata);
+            strcpy(decpw, encrypted);
+        }
+
+        param = parse_get(args, "write", &len);
+        if (len && isalpha(param[0])) {
+            if (!strncmp(param, "true", len))
+                write = 1;
+        }
+
+        if (!decname[0] || !decpw[0])
+            goto nope;
+
+        if (!settings.adduserCb(settings.messager, decname, decpw, write)) {
+            wserr("Invalid params to create_user\n");
+            goto nope;
+        }
+
+        sprintf(buf, "HTTP/1.1 200 OK\r\n"
+                 "Server: KasmVNC/4.0\r\n"
+                 "Connection: close\r\n"
+                 "Content-type: text/plain\r\n"
+                 "Content-length: 6\r\n"
+                 "\r\n"
+                 "200 OK");
+        ws_send(ws_ctx, buf, strlen(buf));
+
+        ret = 1;
+    } else entry("/api/remove_user") {
+        char decname[1024] = "";
+
+        param = parse_get(args, "name", &len);
+        if (len) {
+            memcpy(buf, param, len);
+            buf[len] = '\0';
+            percent_decode(buf, decname);
+        }
+
+        if (!decname[0])
+            goto nope;
+
+        if (!settings.removeCb(settings.messager, decname)) {
+            wserr("Invalid params to remove_user\n");
+            goto nope;
+        }
+
+        sprintf(buf, "HTTP/1.1 200 OK\r\n"
+                 "Server: KasmVNC/4.0\r\n"
+                 "Connection: close\r\n"
+                 "Content-type: text/plain\r\n"
+                 "Content-length: 6\r\n"
+                 "\r\n"
+                 "200 OK");
+        ws_send(ws_ctx, buf, strlen(buf));
+
+        wserr("Passed remove_user request to main thread\n");
+        ret = 1;
+    } else entry("/api/give_control") {
+        char decname[1024] = "";
+
+        param = parse_get(args, "name", &len);
+        if (len) {
+            memcpy(buf, param, len);
+            buf[len] = '\0';
+            percent_decode(buf, decname);
+        }
+
+        if (!decname[0])
+            goto nope;
+
+        if (!settings.givecontrolCb(settings.messager, decname)) {
+            wserr("Invalid params to give_control\n");
+            goto nope;
+        }
+
+        sprintf(buf, "HTTP/1.1 200 OK\r\n"
+                 "Server: KasmVNC/4.0\r\n"
+                 "Connection: close\r\n"
+                 "Content-type: text/plain\r\n"
+                 "Content-length: 6\r\n"
+                 "\r\n"
+                 "200 OK");
+        ws_send(ws_ctx, buf, strlen(buf));
+
+        wserr("Passed give_control request to main thread\n");
+        ret = 1;
     }
 
     #undef entry

common/network/websocket.h

@@ -80,6 +80,10 @@ typedef struct {
     uint8_t *(*screenshotCb)(void *messager, uint16_t w, uint16_t h, const uint8_t q,
                              const uint8_t dedup,
                              uint32_t *len, uint8_t *staging);
+    uint8_t (*adduserCb)(void *messager, const char name[], const char pw[],
+                          const uint8_t write);
+    uint8_t (*removeCb)(void *messager, const char name[]);
+    uint8_t (*givecontrolCb)(void *messager, const char name[]);
 } settings_t;
 
 #ifdef __cplusplus

common/rfb/VNCServerST.cxx

@@ -641,6 +641,71 @@ int VNCServerST::msToNextUpdate()
     return frameTimer.getRemainingMs();
 }
 
+static void checkAPIMessages(network::GetAPIMessager *apimessager)
+{
+  if (pthread_mutex_lock(&apimessager->userMutex))
+    return;
+
+  const unsigned num = apimessager->actionQueue.size();
+  unsigned i;
+  for (i = 0; i < num; i++) {
+    slog.info("Main thread processing user API request %u/%u", i + 1, num);
+
+    const network::GetAPIMessager::action_data &act = apimessager->actionQueue[i];
+    struct kasmpasswd_t *set = NULL;
+    unsigned s;
+    bool found;
+
+    switch (act.action) {
+      case network::GetAPIMessager::USER_REMOVE:
+        set = readkasmpasswd(kasmpasswdpath);
+        found = false;
+        for (s = 0; s < set->num; s++) {
+          if (!strcmp(set->entries[s].user, act.data.user)) {
+            set->entries[s].user[0] = '\0';
+            found = true;
+            break;
+          }
+        }
+
+        if (found) {
+          writekasmpasswd(kasmpasswdpath, set);
+          slog.info("User %s removed", act.data.user);
+        } else {
+          slog.error("Tried to remove nonexistent user %s", act.data.user);
+        }
+      break;
+      case network::GetAPIMessager::USER_GIVE_CONTROL:
+        set = readkasmpasswd(kasmpasswdpath);
+        found = false;
+        for (s = 0; s < set->num; s++) {
+          if (!strcmp(set->entries[s].user, act.data.user)) {
+            set->entries[s].write = 1;
+            found = true;
+          } else {
+            set->entries[s].write = 0;
+          }
+        }
+
+        if (found) {
+          writekasmpasswd(kasmpasswdpath, set);
+          slog.info("User %s given control", act.data.user);
+        } else {
+          slog.error("Tried to give control to nonexistent user %s", act.data.user);
+        }
+      break;
+    }
+
+    if (set) {
+      free(set->entries);
+      free(set);
+    }
+  }
+
+  apimessager->actionQueue.clear();
+  pthread_mutex_unlock(&apimessager->userMutex);
+}
+
 // writeUpdate() is called on a regular interval in order to see what
 // updates are pending and propagates them to the update tracker for
 // each client. It uses the ComparingUpdateTracker's compare() method
@@ -711,9 +776,12 @@ void VNCServerST::writeUpdate()
     }
   }
 
-  if (apimessager)
+  if (apimessager) {
     apimessager->mainUpdateScreen(pb);
 
+    checkAPIMessages(apimessager);
+  }
+
   for (ci = clients.begin(); ci != clients.end(); ci = ci_next) {
     ci_next = ci; ci_next++;