GUAC-716: Add password and password-regex parameters. Search for password prompt if password parameter specified.

src/protocols/telnet/client.c

@@ -30,8 +30,10 @@
 #include <langinfo.h>
 #include <locale.h>
 #include <pthread.h>
+#include <regex.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include <guacamole/client.h>
 #include <guacamole/protocol.h>
@@ -46,6 +48,8 @@ const char* GUAC_CLIENT_ARGS[] = {
     "hostname",
     "port",
     "username",
+    "password",
+    "password-regex",
     "font-name",
     "font-size",
     NULL
@@ -68,6 +72,17 @@ enum __TELNET_ARGS_IDX {
      */
     IDX_USERNAME,
 
+    /**
+     * The password to use when logging in. Optional.
+     */
+    IDX_PASSWORD,
+
+    /**
+     * The regular expression to use when searching for the password prompt.
+     * Optional.
+     */
+    IDX_PASSWORD_REGEX,
+
     /**
      * The name of the font to use within the terminal.
      */
@@ -107,6 +122,34 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
     /* Read parameters */
     strcpy(client_data->hostname,  argv[IDX_HOSTNAME]);
     strcpy(client_data->username,  argv[IDX_USERNAME]);
+    strcpy(client_data->password,  argv[IDX_PASSWORD]);
+
+    /* Set password regex, if needed */
+    if (client_data->password[0] != 0) {
+
+        int compile_result;
+
+        client_data->password_regex = malloc(sizeof(regex_t));
+
+        /* Compile regular expression */
+        if (argv[IDX_PASSWORD_REGEX][0] != 0)
+            compile_result = regcomp(client_data->password_regex, argv[IDX_PASSWORD_REGEX],
+                    REG_EXTENDED | REG_NOSUB | REG_NEWLINE);
+        else
+            compile_result = regcomp(client_data->password_regex, GUAC_TELNET_DEFAULT_REGEX,
+                    REG_EXTENDED | REG_NOSUB | REG_NEWLINE);
+
+        /* Notify of failure to parse/compile */
+        if (compile_result != 0) {
+            guac_client_log_info(client, "Password regular expression could not be compiled. "
+                                         "Password must be entered manually.");
+            free(client_data->password_regex);
+            client_data->password_regex = NULL;
+        }
+
+    }
+    else
+        client_data->password_regex = NULL;
 
     /* Read port */
     if (argv[IDX_PORT][0] != 0)

src/protocols/telnet/client.h

@@ -27,8 +27,13 @@
 #include "terminal.h"
 
 #include <pthread.h>
+#include <regex.h>
+#include <sys/types.h>
+
 #include <libtelnet.h>
 
+#define GUAC_TELNET_DEFAULT_REGEX "^Password:"
+
 /**
  * Telnet-specific client data.
  */
@@ -49,6 +54,18 @@ typedef struct guac_telnet_client_data {
      */
     char username[1024];
 
+    /**
+     * The password to give when authenticating.
+     */
+    char password[1024];
+
+    /**
+     * The regular expression to use when searching for the password
+     * prompt. This will be NULL unless the telnet client is currently
+     * searching for the password prompt.
+     */
+    regex_t* password_regex;
+
     /**
      * The name of the font to use for display rendering.
      */

src/protocols/telnet/guac_handlers.c

@@ -30,7 +30,9 @@
 #include <libtelnet.h>
 
 #include <pthread.h>
+#include <regex.h>
 #include <stdlib.h>
+#include <sys/types.h>
 #include <unistd.h>
 
 int guac_telnet_client_handle_messages(guac_client* client) {
@@ -45,8 +47,10 @@ int guac_telnet_client_mouse_handler(guac_client* client, int x, int y, int mask
     guac_telnet_client_data* client_data = (guac_telnet_client_data*) client->data;
     guac_terminal* term = client_data->term;
 
-    /* Send mouse event */
+    /* Send mouse if not searching for password */
+    if (client_data->password_regex == NULL)
         guac_terminal_send_mouse(term, x, y, mask);
+
     return 0;
 
 }
@@ -56,8 +60,10 @@ int guac_telnet_client_key_handler(guac_client* client, int keysym, int pressed)
     guac_telnet_client_data* client_data = (guac_telnet_client_data*) client->data;
     guac_terminal* term = client_data->term;
 
-    /* Send key */
+    /* Send key if not searching for password */
+    if (client_data->password_regex == NULL)
         guac_terminal_send_key(term, keysym, pressed);
+
     return 0;
 
 }
@@ -95,6 +101,12 @@ int guac_telnet_client_free_handler(guac_client* client) {
         telnet_free(guac_client_data->telnet);
     }
 
+    /* Free password regex */
+    if (guac_client_data->password_regex != NULL) {
+        regfree(guac_client_data->password_regex);
+        free(guac_client_data->password_regex);
+    }
+
     free(client->data);
     return 0;
 

src/protocols/telnet/telnet_client.c

@@ -33,6 +33,7 @@
 #include <netdb.h>
 #include <netinet/in.h>
 #include <pthread.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/select.h>
 #include <sys/socket.h>
@@ -83,6 +84,61 @@ static int __guac_telnet_write_all(int fd, const char* buffer, int size) {
 
 }
 
+/**
+ * Searches for a line matching the stored password regex, appending the given
+ * buffer to the internal pattern matching buffer. The internal pattern match
+ * buffer is cleared whenever a newline is read.
+ */
+static void __guac_telnet_password_search(guac_client* client, const char* buffer, int size) {
+
+    static char line_buffer[1024] = {0};
+    static int length = 0;
+
+    guac_telnet_client_data* client_data = (guac_telnet_client_data*) client->data;
+
+    int i;
+    const char* current;
+
+    /* Ensure line buffer contains only the most recent line */
+    current = buffer;
+    for (i = 0; i < size; i++) {
+
+        /* Reset line buffer and shift input buffer for each newline */
+        if (*(current++) == '\n') {
+            length = 0;
+            buffer += i;
+            size -= i;
+            i = 0;
+        }
+
+    }
+
+    /* Truncate if necessary */
+    if (size + length + 1 > sizeof(line_buffer))
+        size = sizeof(line_buffer) - length - 1;
+
+    /* Append to line */
+    memcpy(&(line_buffer[length]), buffer, size);
+    length += size;
+    line_buffer[length] = '\0';
+
+    /* Send password upon match */
+    if (regexec(client_data->password_regex, line_buffer, 0, NULL, 0) == 0) {
+
+        /* Send password */
+        guac_terminal_send_string(client_data->term, client_data->password);
+        guac_terminal_send_key(client_data->term, 0xFF0D, 1);
+        guac_terminal_send_key(client_data->term, 0xFF0D, 0);
+
+        /* Stop searching for password */
+        regfree(client_data->password_regex);
+        free(client_data->password_regex);
+        client_data->password_regex = NULL;
+
+    }
+
+}
+
 /**
  * Event handler, as defined by libtelnet. This function is passed to
  * telnet_init() and will be called for every event fired by libtelnet,
@@ -95,9 +151,14 @@ static void __guac_telnet_event_handler(telnet_t* telnet, telnet_event_t* event,
 
     switch (event->type) {
 
-        /* User input received */
+        /* Terminal output received */
         case TELNET_EV_DATA:
             guac_terminal_write_stdout(client_data->term, event->data.buffer, event->data.size);
+
+            /* Continue search for password prompt */
+            if (client_data->password_regex != NULL)
+                __guac_telnet_password_search(client, event->data.buffer, event->data.size);
+
             break;
 
         /* Data destined for remote end */