signal-desktop: replace unlicensed Apple emoji (#337161)

"""Copy Noto Color Emoji PNGs into an extracted Signal ASAR archive.

Signal loads small Apple emoji PNGs directly from

`node_modules/emoji-datasource-apple/img/apple/64`, and downloads and

caches large Apple emoji WebP files in `.proto` bundles on the fly. The

latter are not a copyright concern for the Nixpkgs cache, but would

result in inconsistent presentation between small and large emoji.

We skip the complexity and buy some additional privacy by replacing the

`emoji://jumbo?emoji=` URL prefix with a `file://` path to the copied

PNGs inside the ASAR archive, and linking the `node_modules` PNG paths

directly to them.

"""

import json

import shutil

import sys

from pathlib import Path

def signal_name_to_emoji(signal_emoji_name: str) -> str:

    r"""Return the emoji corresponding to a Signal emoji name.

    Signal emoji names are concatenations of UTF‐16 code units,

    represented in lowercase big‐endian hex padded to four digits.

    >>> signal_name_to_emoji("d83dde36200dd83cdf2bfe0f")

    '😶‍🌫️'

    >>> b"\xd8\x3d\xde\x36\x20\x0d\xd8\x3c\xdf\x2b\xfe\x0f".decode("utf-16-be")

    '😶‍🌫️'

    """

    hex_bytes = zip(signal_emoji_name[::2], signal_emoji_name[1::2])

    emoji_utf_16_be = bytes(

        int("".join(hex_pair), 16) for hex_pair in hex_bytes

    )

    return emoji_utf_16_be.decode("utf-16-be")

def emoji_to_noto_name(emoji: str) -> str:

    r"""Return the Noto emoji name of an emoji.

    Noto emoji names are underscore‐separated Unicode scalar values,

    represented in lowercase big‐endian hex padded to at least four

    digits. Any U+FE0F variant selectors are omitted.

    >>> emoji_to_noto_name("😶‍🌫️")

    '1f636_200d_1f32b'

    >>> emoji_to_noto_name("\U0001f636\u200d\U0001f32b\ufe0f")

    '1f636_200d_1f32b'

    """

    return "_".join(

        f"{ord(scalar_value):04x}"

        for scalar_value in emoji

        if scalar_value != "\ufe0f"

    )

def emoji_to_emoji_data_name(emoji: str) -> str:

    r"""Return the npm emoji-data emoji name of an emoji.

    emoji-data emoji names are hyphen‐minus‐separated Unicode scalar

    values, represented in lowercase big‐endian hex padded to at least

    four digits.

    >>> emoji_to_emoji_data_name("😶‍🌫️")

    '1f636-200d-1f32b-fe0f'

    >>> emoji_to_emoji_data_name("\U0001f636\u200d\U0001f32b\ufe0f")

    '1f636-200d-1f32b-fe0f'

    """

    return "-".join(f"{ord(scalar_value):04x}" for scalar_value in emoji)

def _main() -> None:

    noto_png_path, asar_root = (Path(arg) for arg in sys.argv[1:])

    asar_root = asar_root.absolute()

    out_path = asar_root / "images" / "nixpkgs-emoji"

    out_path.mkdir(parents=True)

    emoji_data_out_path = (

        asar_root

        / "node_modules"

        / "emoji-datasource-apple"

        / "img"

        / "apple"

        / "64"

    )

    emoji_data_out_path.mkdir(parents=True)

    jumbomoji_json_path = asar_root / "build" / "jumbomoji.json"

    with jumbomoji_json_path.open() as jumbomoji_json_file:

        jumbomoji_packs = json.load(jumbomoji_json_file)

    for signal_emoji_names in jumbomoji_packs.values():

        for signal_emoji_name in signal_emoji_names:

            emoji = signal_name_to_emoji(signal_emoji_name)

            try:

                shutil.copy(

                    noto_png_path / f"emoji_u{emoji_to_noto_name(emoji)}.png",

                    out_path / emoji,

                )

            except FileNotFoundError:

                print(

                    f"Missing Noto emoji: {emoji} {signal_emoji_name}",

                    file=sys.stderr,

                )

                continue

            (

                emoji_data_out_path / f"{emoji_to_emoji_data_name(emoji)}.png"

            ).symlink_to(out_path / emoji)

    print(out_path.relative_to(asar_root))

if __name__ == "__main__":

    _main()

{ stdenv

, lib

, callPackage

, fetchurl

, autoPatchelfHook

, noto-fonts-color-emoji

, dpkg

, asar

, rsync

, python3

, wrapGAppsHook3

, makeWrapper

, nixosTests

let

  inherit (stdenv) targetPlatform;

  ARCH = if targetPlatform.isAarch64 then "arm64" else "x64";

  # Noto Color Emoji PNG files for emoji replacement; see below.

  noto-fonts-color-emoji-png = noto-fonts-color-emoji.overrideAttrs (prevAttrs: {

    pname = "noto-fonts-color-emoji-png";

    # The build produces 136×128 PNGs by default for arcane font

    # reasons, but we want square PNGs.

    buildFlags = prevAttrs.buildFlags or [ ] ++ [ "BODY_DIMENSIONS=128x128" ];

    makeTargets = [ "compressed" ];

    installPhase = ''

      runHook preInstall

      mkdir -p $out/share

      mv build/compressed_pngs $out/share/noto-fonts-color-emoji-png

      python3 add_aliases.py --srcdir=$out/share/noto-fonts-color-emoji-png

      runHook postInstall

    '';

  });

in

stdenv.mkDerivation rec {

  inherit pname version;

  src = fetchurl {

    inherit url hash;

    recursiveHash = true;

    downloadToTemp = true;

    nativeBuildInputs = [ dpkg asar ];

    # Signal ships the Apple emoji set without a licence via an npm

    # package and upstream does not seem terribly interested in fixing

    # this; see:

    #

    # * <https://github.com/signalapp/Signal-Android/issues/5862>

    # * <https://whispersystems.discoursehosting.net/t/signal-is-likely-violating-apple-license-terms-by-using-apple-emoji-in-the-sticker-creator-and-android-and-desktop-apps/52883>

    #

    # We work around this by replacing it with the Noto Color Emoji

    # set, which is available under a FOSS licence and more likely to

    # be used on a NixOS machine anyway. The Apple emoji are removed

    # during `fetchurl` to ensure that the build doesn’t cache the

    # unlicensed emoji files, but the rest of the work is done in the

    # main derivation.

    postFetch = ''

      dpkg-deb -x $downloadedFile $out

      asar extract "$out/opt/${dir}/resources/app.asar" $out/asar-contents

      rm -r \

        "$out/opt/${dir}/resources/app.asar"{,.unpacked} \

        $out/asar-contents/node_modules/emoji-datasource-apple

    '';

  };

  nativeBuildInputs = [

    rsync

    asar

    python3

    autoPatchelfHook

    dpkg

    (wrapGAppsHook3.override { inherit makeWrapper; })

  ];

    wayland

  ];

  unpackPhase = "dpkg-deb -x $src .";

  dontBuild = true;

  dontConfigure = true;

  unpackPhase = ''

    rsync -a --chmod=+w $src/ .

  '';

  installPhase = ''

    runHook preInstall

    # Create required symlinks:

    ln -s libGLESv2.so "$out/lib/${dir}/libGLESv2.so.2"

    # Copy the Noto Color Emoji PNGs into the ASAR contents. See `src`

    # for the motivation, and the script for the technical details.

    emojiPrefix=$(

      python3 ${./copy-noto-emoji.py} \

      ${noto-fonts-color-emoji-png}/share/noto-fonts-color-emoji-png \

      asar-contents

    )

    # Replace the URL used for fetching large versions of emoji with

    # the local path to our copied PNGs.

    substituteInPlace asar-contents/preload.bundle.js \

      --replace-fail \

        'emoji://jumbo?emoji=' \

        "file://$out/lib/${lib.escapeURL dir}/resources/app.asar/$emojiPrefix/"

    # `asar(1)` copies files from the corresponding `.unpacked`

    # directory when extracting, and will put them back in the modified

    # archive if you don’t specify them again when repacking. Signal

    # leaves their native `.node` libraries unpacked, so we match that.

    asar pack \

      --unpack '*.node' \

      asar-contents \

      "$out/lib/${dir}/resources/app.asar"

    runHook postInstall

  '';

    '';

    homepage = "https://signal.org/";

    changelog = "https://github.com/signalapp/Signal-Desktop/releases/tag/v${version}";

    license = lib.licenses.agpl3Only;

    maintainers = with lib.maintainers; [ eclairevoyant mic92 equirosa urandom bkchr teutat3s ];

    license = [

      lib.licenses.agpl3Only

      # Various npm packages

      lib.licenses.free

    ];

    maintainers = with lib.maintainers; [

      eclairevoyant

      mic92

      equirosa

      urandom

      bkchr

      teutat3s

      emily

    ];

    mainProgram = pname;

    platforms = [ "x86_64-linux" "aarch64-linux" ];

    sourceProvenance = with lib.sourceTypes; [ binaryNativeCode ];

[tool.mypy]

files = ["*.py"]

strict = true

[tool.ruff]

line-length = 80

[tool.ruff.lint]

select = ["ALL"]

ignore = ["COM812", "D203", "D213", "ISC001", "T201"]

allowed-confusables = ["‐"]

[tool.ruff.format]

docstring-code-format = true

docstring-code-line-length = "dynamic"

  dir = "Signal";

  version = "7.19.0";

  url = "https://github.com/0mniteck/Signal-Desktop-Mobian/raw/${version}/builds/release/signal-desktop_${version}_arm64.deb";

  hash = "sha256-L5Wj1ofMR+QJezd4V6pAhkINLF6y9EB5VNFAIOZE5PU=";

  hash = "sha256-wyXVZUuY1TDGAVq7Gx9r/cuBuoMmSk9KQttTJlIN+k8=";

}

  dir = "Signal Beta";

  version = "7.19.0-beta.1";

  url = "https://updates.signal.org/desktop/apt/pool/s/signal-desktop-beta/signal-desktop-beta_${version}_amd64.deb";

  hash = "sha256-kD08xke+HYhwAZG7jmU1ILo013556vNcvAFc/+9BTjg=";

  hash = "sha256-dIZvzJ45c5kL+2HEaKrtbck5Zz572pQAj3YTenzz6Zs=";

}