GUACAMOLE-478: Add optional clipboard line ending normalization for RDP.

src/protocols/rdp/channels/cliprdr.c

@@ -352,10 +352,11 @@ static UINT guac_rdp_cliprdr_format_data_request(CliprdrClientContext* cliprdr,
 
     guac_client* client = clipboard->client;
     guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
+    guac_rdp_settings* settings = rdp_client->settings;
 
     guac_client_log(client, GUAC_LOG_TRACE, "CLIPRDR: Received format data request.");
 
-    guac_iconv_write* writer;
+    guac_iconv_write* remote_writer;
     const char* input = clipboard->clipboard->buffer;
     char* output = malloc(GUAC_RDP_CLIPBOARD_MAX_LENGTH);
 
@@ -363,11 +364,11 @@ static UINT guac_rdp_cliprdr_format_data_request(CliprdrClientContext* cliprdr,
     switch (format_data_request->requestedFormatId) {
 
         case CF_TEXT:
-            writer = GUAC_WRITE_CP1252;
+            remote_writer = settings->clipboard_crlf ? GUAC_WRITE_CP1252_CRLF : GUAC_WRITE_CP1252;
             break;
 
         case CF_UNICODETEXT:
-            writer = GUAC_WRITE_UTF16;
+            remote_writer = settings->clipboard_crlf ? GUAC_WRITE_UTF16_CRLF : GUAC_WRITE_UTF16;
             break;
 
         /* Warn if clipboard data cannot be sent as intended due to a violation
@@ -386,8 +387,9 @@ static UINT guac_rdp_cliprdr_format_data_request(CliprdrClientContext* cliprdr,
     /* Send received clipboard data to the RDP server in the format
      * requested */
     BYTE* start = (BYTE*) output;
-    guac_iconv(GUAC_READ_UTF8, &input, clipboard->clipboard->length,
+    guac_iconv_read* local_reader = settings->normalize_clipboard ? GUAC_READ_UTF8_NORMALIZED : GUAC_READ_UTF8;
-               writer, &output, GUAC_RDP_CLIPBOARD_MAX_LENGTH);
+    guac_iconv(local_reader, &input, clipboard->clipboard->length,
+            remote_writer, &output, GUAC_RDP_CLIPBOARD_MAX_LENGTH);
 
     CLIPRDR_FORMAT_DATA_RESPONSE data_response = {
         .requestedFormatData = (BYTE*) start,
@@ -449,7 +451,7 @@ static UINT guac_rdp_cliprdr_format_data_response(CliprdrClientContext* cliprdr,
 
     char received_data[GUAC_RDP_CLIPBOARD_MAX_LENGTH];
 
-    guac_iconv_read* reader;
+    guac_iconv_read* remote_reader;
     const char* input = (char*) format_data_response->requestedFormatData;
     char* output = received_data;
 
@@ -458,12 +460,12 @@ static UINT guac_rdp_cliprdr_format_data_response(CliprdrClientContext* cliprdr,
 
         /* Non-Unicode (Windows CP-1252) */
         case CF_TEXT:
-            reader = GUAC_READ_CP1252;
+            remote_reader = settings->normalize_clipboard ? GUAC_READ_CP1252_NORMALIZED : GUAC_READ_CP1252;
             break;
 
         /* Unicode (UTF-16) */
         case CF_UNICODETEXT:
-            reader = GUAC_READ_UTF16;
+            remote_reader = settings->normalize_clipboard ? GUAC_READ_UTF16_NORMALIZED : GUAC_READ_UTF16;
             break;
 
         /* If the format ID stored within the guac_rdp_clipboard structure is actually
@@ -481,7 +483,7 @@ static UINT guac_rdp_cliprdr_format_data_response(CliprdrClientContext* cliprdr,
 
     /* Convert, store, and forward the clipboard data received from RDP
      * server */
-    if (guac_iconv(reader, &input, format_data_response->dataLen,
+    if (guac_iconv(remote_reader, &input, format_data_response->dataLen,
             GUAC_WRITE_UTF8, &output, sizeof(received_data))) {
         int length = strnlen(received_data, sizeof(received_data));
         guac_common_clipboard_reset(clipboard->clipboard, "text/plain");

src/protocols/rdp/settings.c

@@ -130,6 +130,7 @@ const char* GUAC_RDP_CLIENT_ARGS[] = {
     "wol-wait-time",
 
     "force-lossless",
+    "normalize-clipboard",
     NULL
 };
 
@@ -647,6 +648,16 @@ enum RDP_ARGS_IDX {
      */
     IDX_FORCE_LOSSLESS,
 
+    /**
+     * Controls whether the text content of the clipboard should be
+     * automatically normalized to use a particular line ending format. Valid
+     * values are "preserve", to preserve line endings verbatim, "windows" to
+     * transform all line endings to Windows-style CRLF sequences, or "unix" to
+     * transform all line endings to Unix-style newline characters ('\n'). By
+     * default, line endings within the clipboard are preserved.
+     */
+    IDX_NORMALIZE_CLIPBOARD,
+
     RDP_ARGS_COUNT
 };
 
@@ -1167,7 +1178,36 @@ guac_rdp_settings* guac_rdp_parse_args(guac_user* user,
     settings->disable_paste =
         guac_user_parse_args_boolean(user, GUAC_RDP_CLIENT_ARGS, argv,
                 IDX_DISABLE_PASTE, 0);
-    
+
+    /* Normalize clipboard line endings to Unix format */
+    if (strcmp(argv[IDX_NORMALIZE_CLIPBOARD], "unix") == 0) {
+        guac_user_log(user, GUAC_LOG_INFO, "Clipboard line ending normalization: Unix (LF)");
+        settings->normalize_clipboard = 1;
+        settings->clipboard_crlf = 0;
+    }
+
+    /* Normalize clipboard line endings to Windows format */
+    else if (strcmp(argv[IDX_NORMALIZE_CLIPBOARD], "windows") == 0) {
+        guac_user_log(user, GUAC_LOG_INFO, "Clipboard line ending normalization: Windows (CRLF)");
+        settings->normalize_clipboard = 1;
+        settings->clipboard_crlf = 1;
+    }
+
+    /* Preserve clipboard line ending format */
+    else if (strcmp(argv[IDX_NORMALIZE_CLIPBOARD], "preserve") == 0) {
+        guac_user_log(user, GUAC_LOG_INFO, "Clipboard line ending normalization: Preserve (none)");
+        settings->normalize_clipboard = 0;
+        settings->clipboard_crlf = 0;
+    }
+
+    /* If nothing given, default to preserving line endings */
+    else {
+        guac_user_log(user, GUAC_LOG_INFO, "No clipboard line-ending normalization specified. Defaulting to preserving the format of all line endings.");
+        settings->normalize_clipboard = 0;
+        settings->clipboard_crlf = 0;
+    }
+
+
     /* Parse Wake-on-LAN (WoL) settings */
     settings->wol_send_packet =
         guac_user_parse_args_boolean(user, GUAC_RDP_CLIENT_ARGS, argv,

src/protocols/rdp/settings.h

@@ -323,6 +323,19 @@ typedef struct guac_rdp_settings {
      */
     int disable_paste;
 
+    /**
+     * Whether line endings within the clipboard should be automatically
+     * normalized to Unix-style newline characters.
+     */
+    int normalize_clipboard;
+
+    /**
+     * Whether Unix-style newline characters within the clipboard should be
+     * automatically translated to CRLF sequences before transmission to the
+     * RDP server.
+     */
+    int clipboard_crlf;
+
     /**
      * Whether the desktop wallpaper should be visible. If unset, the desktop
      * wallpaper will be hidden, reducing the amount of bandwidth required.