Merge branch 'zrle' of https://github.com/pauldumais/noVNC

3 files changed, 312 insertions, 0 deletions

diff --git a/core/decoders/zrle.js b/core/decoders/zrle.js
new file mode 100644
index 0000000..97fbd58
--- /dev/null
+++ b/core/decoders/zrle.js
@@ -0,0 +1,185 @@
+/*
+ * noVNC: HTML5 VNC client
+ * Copyright (C) 2021 The noVNC Authors
+ * Licensed under MPL 2.0 (see LICENSE.txt)
+ *
+ * See README.md for usage and integration instructions.
+ *
+ */
+
+import Inflate from "../inflator.js";
+
+const ZRLE_TILE_WIDTH = 64;
+const ZRLE_TILE_HEIGHT = 64;
+
+export default class ZRLEDecoder {
+    constructor() {
+        this._length = 0;
+        this._inflator = new Inflate();
+
+        this._pixelBuffer = new Uint8Array(ZRLE_TILE_WIDTH * ZRLE_TILE_HEIGHT * 4);
+        this._tileBuffer = new Uint8Array(ZRLE_TILE_WIDTH * ZRLE_TILE_HEIGHT * 4);
+    }
+
+    decodeRect(x, y, width, height, sock, display, depth) {
+        if (this._length === 0) {
+            if (sock.rQwait("ZLib data length", 4)) {
+                return false;
+            }
+            this._length = sock.rQshift32();
+        }
+        if (sock.rQwait("Zlib data", this._length)) {
+            return false;
+        }
+
+        const data = sock.rQshiftBytes(this._length);
+
+        this._inflator.setInput(data);
+
+        for (let ty = y; ty < y + height; ty += ZRLE_TILE_HEIGHT) {
+            let th = Math.min(ZRLE_TILE_HEIGHT, y + height - ty);
+
+            for (let tx = x; tx < x + width; tx += ZRLE_TILE_WIDTH) {
+                let tw = Math.min(ZRLE_TILE_WIDTH, x + width - tx);
+
+                const tileSize = tw * th;
+                const subencoding = this._inflator.inflate(1)[0];
+                if (subencoding === 0) {
+                    // raw data
+                    const data = this._readPixels(tileSize);
+                    display.blitImage(tx, ty, tw, th, data, 0, false);
+                } else if (subencoding === 1) {
+                    // solid
+                    const background = this._readPixels(1);
+                    display.fillRect(tx, ty, tw, th, [background[0], background[1], background[2]]);
+                } else if (subencoding >= 2 && subencoding <= 16) {
+                    const data = this._decodePaletteTile(subencoding, tileSize, tw, th);
+                    display.blitImage(tx, ty, tw, th, data, 0, false);
+                } else if (subencoding === 128) {
+                    const data = this._decodeRLETile(tileSize);
+                    display.blitImage(tx, ty, tw, th, data, 0, false);
+                } else if (subencoding >= 130 && subencoding <= 255) {
+                    const data = this._decodeRLEPaletteTile(subencoding - 128, tileSize);
+                    display.blitImage(tx, ty, tw, th, data, 0, false);
+                } else {
+                    throw new Error('Unknown subencoding: ' + subencoding);
+                }
+            }
+        }
+        this._length = 0;
+        return true;
+    }
+
+    _getBitsPerPixelInPalette(paletteSize) {
+        if (paletteSize <= 2) {
+            return 1;
+        } else if (paletteSize <= 4) {
+            return 2;
+        } else if (paletteSize <= 16) {
+            return 4;
+        }
+    }
+
+    _readPixels(pixels) {
+        let data = this._pixelBuffer;
+        const buffer = this._inflator.inflate(3*pixels);
+        for (let i = 0, j = 0; i < pixels*4; i += 4, j += 3) {
+            data[i]     = buffer[j];
+            data[i + 1] = buffer[j + 1];
+            data[i + 2] = buffer[j + 2];
+            data[i + 3] = 255;  // Add the Alpha
+        }
+        return data;
+    }
+
+    _decodePaletteTile(paletteSize, tileSize, tilew, tileh) {
+        const data = this._tileBuffer;
+        const palette = this._readPixels(paletteSize);
+        const bitsPerPixel = this._getBitsPerPixelInPalette(paletteSize);
+        const mask = (1 << bitsPerPixel) - 1;
+
+        let offset = 0;
+        let encoded = this._inflator.inflate(1)[0];
+
+        for (let y=0; y<tileh; y++) {
+            let shift = 8-bitsPerPixel;
+            for (let x=0; x<tilew; x++) {
+                if (shift<0) {
+                    shift=8-bitsPerPixel;
+                    encoded = this._inflator.inflate(1)[0];
+                }
+                let indexInPalette = (encoded>>shift) & mask;
+
+                data[offset] = palette[indexInPalette * 4];
+                data[offset + 1] = palette[indexInPalette * 4 + 1];
+                data[offset + 2] = palette[indexInPalette * 4 + 2];
+                data[offset + 3] = palette[indexInPalette * 4 + 3];
+                offset += 4;
+                shift-=bitsPerPixel;
+            }
+            if (shift<8-bitsPerPixel && y<tileh-1) {
+                encoded =  this._inflator.inflate(1)[0];
+            }
+        }
+        return data;
+    }
+
+    _decodeRLETile(tileSize) {
+        const data = this._tileBuffer;
+        let i = 0;
+        while (i < tileSize) {
+            const pixel = this._readPixels(1);
+            const length = this._readRLELength();
+            for (let j = 0; j < length; j++) {
+                data[i * 4] = pixel[0];
+                data[i * 4 + 1] = pixel[1];
+                data[i * 4 + 2] = pixel[2];
+                data[i * 4 + 3] = pixel[3];
+                i++;
+            }
+        }
+        return data;
+    }
+
+    _decodeRLEPaletteTile(paletteSize, tileSize) {
+        const data = this._tileBuffer;
+
+        // palette
+        const palette = this._readPixels(paletteSize);
+
+        let offset = 0;
+        while (offset < tileSize) {
+            let indexInPalette = this._inflator.inflate(1)[0];
+            let length = 1;
+            if (indexInPalette >= 128) {
+                indexInPalette -= 128;
+                length = this._readRLELength();
+            }
+            if (indexInPalette > paletteSize) {
+                throw new Error('Too big index in palette: ' + indexInPalette + ', palette size: ' + paletteSize);
+            }
+            if (offset + length > tileSize) {
+                throw new Error('Too big rle length in palette mode: ' + length + ', allowed length is: ' + (tileSize - offset));
+            }
+
+            for (let j = 0; j < length; j++) {
+                data[offset * 4] = palette[indexInPalette * 4];
+                data[offset * 4 + 1] = palette[indexInPalette * 4 + 1];
+                data[offset * 4 + 2] = palette[indexInPalette * 4 + 2];
+                data[offset * 4 + 3] = palette[indexInPalette * 4 + 3];
+                offset++;
+            }
+        }
+        return data;
+    }
+
+    _readRLELength() {
+        let length = 0;
+        let current = 0;
+        do {
+            current = this._inflator.inflate(1)[0];
+            length += current;
+        } while (current === 255);
+        return length + 1;
+    }
+}
diff --git a/core/rfb.js b/core/rfb.js
index 084a457..bc52f4a 100644
--- a/core/rfb.js
+++ b/core/rfb.js
@@ -32,6 +32,7 @@ import RREDecoder from "./decoders/rre.js";
 import HextileDecoder from "./decoders/hextile.js";
 import TightDecoder from "./decoders/tight.js";
 import TightPNGDecoder from "./decoders/tightpng.js";
+import ZRLEDecoder from "./decoders/zrle.js";
 
 // How many seconds to wait for a disconnect to finish
 const DISCONNECT_TIMEOUT = 3;
@@ -218,6 +219,7 @@ export default class RFB extends EventTargetMixin {
         this._decoders[encodings.encodingHextile] = new HextileDecoder();
         this._decoders[encodings.encodingTight] = new TightDecoder();
         this._decoders[encodings.encodingTightPNG] = new TightPNGDecoder();
+        this._decoders[encodings.encodingZRLE] = new ZRLEDecoder();
 
         // NB: nothing that needs explicit teardown should be done
         // before this point, since this can throw an exception
@@ -1772,6 +1774,7 @@ export default class RFB extends EventTargetMixin {
         if (this._fbDepth == 24) {
             encs.push(encodings.encodingTight);
             encs.push(encodings.encodingTightPNG);
+            encs.push(encodings.encodingZRLE);
             encs.push(encodings.encodingHextile);
             encs.push(encodings.encodingRRE);
         }
diff --git a/tests/test.zrle.js b/tests/test.zrle.js
new file mode 100644
index 0000000..e09d208
--- /dev/null
+++ b/tests/test.zrle.js
@@ -0,0 +1,124 @@
+const expect = chai.expect;
+
+import Websock from '../core/websock.js';
+import Display from '../core/display.js';
+
+import ZRLEDecoder from '../core/decoders/zrle.js';
+
+import FakeWebSocket from './fake.websocket.js';
+
+function testDecodeRect(decoder, x, y, width, height, data, display, depth) {
+    let sock;
+
+    sock = new Websock;
+    sock.open("ws://example.com");
+
+    sock.on('message', () => {
+        decoder.decodeRect(x, y, width, height, sock, display, depth);
+    });
+
+    // Empty messages are filtered at multiple layers, so we need to
+    // do a direct call
+    if (data.length === 0) {
+        decoder.decodeRect(x, y, width, height, sock, display, depth);
+    } else {
+        sock._websocket._receiveData(new Uint8Array(data));
+    }
+
+    display.flip();
+}
+
+describe('ZRLE Decoder', function () {
+    let decoder;
+    let display;
+
+    before(FakeWebSocket.replace);
+    after(FakeWebSocket.restore);
+
+    beforeEach(function () {
+        decoder = new ZRLEDecoder();
+        display = new Display(document.createElement('canvas'));
+        display.resize(4, 4);
+    });
+
+    it('should handle the Raw subencoding', function () {
+        testDecodeRect(decoder, 0, 0, 4, 4,
+                       [0x00, 0x00, 0x00, 0x0e, 0x78, 0x5e, 0x62, 0x60, 0x60, 0xf8, 0x4f, 0x12, 0x02, 0x00, 0x00, 0x00, 0xff, 0xff],
+                       display, 24);
+
+        let targetData = new Uint8Array([
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff
+        ]);
+
+        expect(display).to.have.displayed(targetData);
+    });
+
+    it('should handle the Solid subencoding', function () {
+        testDecodeRect(decoder, 0, 0, 4, 4,
+                       [0x00, 0x00, 0x00, 0x0c, 0x78, 0x5e, 0x62, 0x64, 0x60, 0xf8, 0x0f, 0x00, 0x00, 0x00, 0xff, 0xff],
+                       display, 24);
+
+        let targetData = new Uint8Array([
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff
+        ]);
+
+        expect(display).to.have.displayed(targetData);
+    });
+
+
+    it('should handle the Palette Tile subencoding', function () {
+        testDecodeRect(decoder, 0, 0, 4, 4,
+                       [0x00, 0x00, 0x00, 0x12,  0x78, 0x5E, 0x62, 0x62, 0x60, 248, 0xff, 0x9F, 0x01, 0x08, 0x3E, 0x7C, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff],
+                       display, 24);
+
+        let targetData = new Uint8Array([
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff,
+            0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff
+        ]);
+
+        expect(display).to.have.displayed(targetData);
+    });
+
+    it('should handle the RLE Tile subencoding', function () {
+        testDecodeRect(decoder, 0, 0, 4, 4,
+                       [0x00, 0x00, 0x00, 0x0d, 0x78, 0x5e, 0x6a, 0x60, 0x60, 0xf8, 0x2f, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff],
+                       display, 24);
+
+        let targetData = new Uint8Array([
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff
+        ]);
+
+        expect(display).to.have.displayed(targetData);
+    });
+
+    it('should handle the RLE Palette Tile subencoding', function () {
+        testDecodeRect(decoder, 0, 0, 4, 4,
+                       [0x00, 0x00, 0x00, 0x11, 0x78, 0x5e, 0x6a, 0x62, 0x60, 0xf8, 0xff, 0x9f, 0x81, 0xa1, 0x81, 0x1f, 0x00, 0x00, 0x00, 0xff, 0xff],
+                       display, 24);
+
+        let targetData = new Uint8Array([
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff,
+            0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0x00, 0x00, 0xff, 0xff
+        ]);
+
+        expect(display).to.have.displayed(targetData);
+    });
+
+    it('should fail on an invalid subencoding', function () {
+        let data = [0x00, 0x00, 0x00, 0x0c, 0x78, 0x5e, 0x6a, 0x64, 0x60, 0xf8, 0x0f, 0x00, 0x00, 0x00, 0xff, 0xff];
+        expect(() => testDecodeRect(decoder, 0, 0, 4, 4, data, display, 24)).to.throw();
+    });
+});