Package: guix-patches;
Reported by: Marius Bakke <marius <at> gnu.org>
Date: Fri, 30 Oct 2020 18:30:01 UTC
Severity: normal
Tags: patch
Done: Marius Bakke <marius <at> gnu.org>
Bug is archived. No further changes may be made.
Message #20 received at 44335 <at> debbugs.gnu.org (full text, mbox):
From: Marius Bakke <marius <at> gnu.org> To: 44335 <at> debbugs.gnu.org Subject: [PATCH v2 2/3] Add (gnu build chromium-extension). Date: Mon, 2 Nov 2020 01:22:27 +0100
* gnu/build/chromium-extension.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Adjust accordingly.
---
gnu/build/chromium-extension.scm | 192 +++++++++++++++++++++++++++++++
gnu/local.mk | 1 +
2 files changed, 193 insertions(+)
create mode 100644 gnu/build/chromium-extension.scm
diff --git a/gnu/build/chromium-extension.scm b/gnu/build/chromium-extension.scm
new file mode 100644
index 0000000000..35f49d788c
--- /dev/null
+++ b/gnu/build/chromium-extension.scm
@@ -0,0 +1,192 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2020 Marius Bakke <marius <at> gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu build chromium-extension)
+ #:use-module (gcrypt base16)
+ #:use-module ((gcrypt hash) #:prefix hash:)
+ #:use-module (ice-9 iconv)
+ #:use-module (guix gexp)
+ #:use-module (guix packages)
+ #:use-module (gnu packages base)
+ #:use-module (gnu packages check)
+ #:use-module (gnu packages chromium)
+ #:use-module (gnu packages gnupg)
+ #:use-module (gnu packages tls)
+ #:use-module (gnu packages xorg)
+ #:use-module (guix build-system trivial)
+ #:export (make-chromium-extension))
+
+;;; Commentary:
+;;;
+;;; Tools to deal with Chromium extensions.
+;;;
+;;; Code:
+
+(define (make-signing-key seed)
+ "Return a derivation for a deterministic PKCS #8 private key using SEED."
+
+ (define sha256sum
+ (bytevector->base16-string (hash:sha256 (string->bytevector seed "UTF-8"))))
+
+ ;; certtool.c wants a 56 byte seed for a 2048 bit key.
+ (define size 2048)
+ (define normalized-seed (string-take sha256sum 56))
+
+ (computed-file (string-append seed "-signing-key.pem")
+ #~(system* #$(file-append gnutls "/bin/certtool")
+ "--generate-privkey"
+ "--key-type=rsa"
+ "--pkcs8"
+ ;; Use the provable FIPS-PUB186-4 algorithm for
+ ;; deterministic results.
+ "--provable"
+ "--password="
+ "--no-text"
+ (string-append "--bits=" #$(number->string size))
+ (string-append "--seed=" #$normalized-seed)
+ "--outfile" #$output)
+ #:local-build? #t))
+
+(define* (make-crx package+output signing-key)
+ "Create a signed \".crx\" file from the unpacked Chromium extension residing
+in PACKAGE+OUTPUT, a (list package output) pair. The extension will be signed
+with SIGNING-KEY."
+ (with-imported-modules '((guix build utils))
+ (computed-file
+ "chromium-extension.crx"
+ #~(begin
+ ;; This is not great. We pull Xorg and Chromium just to Zip and
+ ;; sign an extension. This should be implemented with something
+ ;; lighter. (TODO: where is the documentation..?)
+ (use-modules (guix build utils))
+ (let ((chromium #$(file-append ungoogled-chromium "/bin/chromium"))
+ (xvfb #$(file-append xorg-server "/bin/Xvfb"))
+ (packdir "/tmp/extension"))
+ (mkdir-p (dirname packdir))
+ (copy-recursively (ungexp (car package+output) (cadr package+output))
+ packdir)
+ (system (string-append xvfb " :1 &"))
+ (setenv "DISPLAY" ":1")
+ (sleep 2) ;give Xorg some time to initialize...
+ ;; Chromium stores the current time in the .crx Zip archive.
+ ;; Sidestep that by using "faketime" for determinism.
+ ;; FIXME (core-updates): faketime is missing an absolute reference
+ ;; to 'date', hence the need to set PATH.
+ (setenv "PATH" #$(file-append coreutils "/bin"))
+ (invoke #$(file-append libfaketime "/bin/faketime")
+ "2000-01-01 00:00:00"
+ chromium
+ "--user-data-dir=/tmp/signing-profile"
+ (string-append "--pack-extension=" packdir)
+ (string-append "--pack-extension-key=" #$signing-key))
+ (copy-file (string-append packdir ".crx") #$output)))
+ #:local-build? #t)))
+
+(define* (crx->chromium-json crx version)
+ "Return a derivation that creates a Chromium JSON settings file for the
+unpacked extension residing in output PACKAGE-OUTPUT of PACKAGE."
+ (computed-file "extension.json"
+ #~(call-with-output-file #$output
+ (lambda (port)
+ ;; Documentation for the JSON format can be found in
+ ;; extensions/common/extension.h and
+ ;; chrome/browser/extensions/external_provider_impl.cc.
+ (format port "
+{
+ \"external_crx\": \"~a\",
+ \"external_version\": \"~a\"
+}
+"
+ #$crx #$version)))
+ #:local-build? #t))
+
+
+(define (signing-key->public-der key)
+ "Return a derivation for a file containing the public key of KEY in DER
+format."
+ (computed-file "der"
+ #~(system* #$(file-append gnutls "/bin/certtool")
+ "--load-privkey" #$key
+ "--pubkey-info"
+ "--outfile" #$output
+ "--outder")
+ #:local-build? #t))
+
+(define (chromium-json->profile-object json signing-key)
+ "Return a derivation that installs JSON to the directory searched by
+Chromium, using a file name (aka extension ID) derived from SIGNING-KEY."
+ (define der (signing-key->public-der signing-key))
+
+ (with-extensions (list guile-gcrypt)
+ (with-imported-modules '((guix build utils))
+ (computed-file
+ "chromium-extension.json"
+ #~(begin
+ (use-modules (guix build utils)
+ (gcrypt base16)
+ (gcrypt hash))
+ (define (base16-string->chromium-base16 str)
+ ;; Translate STR, a hexadecimal string, to a Chromium-style
+ ;; representation using the letters a-p (where a=0, p=15).
+ (define s1 "0123456789abcdef")
+ (define s2 "abcdefghijklmnop")
+ (let loop ((chars (string->list str))
+ (converted '()))
+ (if (null? chars)
+ (list->string (reverse converted))
+ (loop (cdr chars) (cons (string-ref
+ s2 (string-index s1 (car chars)))
+ converted)))))
+
+ (let* ((checksum (bytevector->base16-string (file-sha256 #$der)))
+ (file-name (base16-string->chromium-base16
+ (string-take checksum 32)))
+ (extension-directory (string-append #$output
+ "/share/chromium/extensions")))
+ (mkdir-p extension-directory)
+ (symlink #$json (string-append extension-directory "/"
+ file-name ".json"))))
+ #:local-build? #t))))
+
+(define* (make-chromium-extension p #:optional (output "out"))
+ "Create a Chromium extension from package P and return a package that,
+when installed, will make the extension contained in P available as a
+Chromium browser extension. OUTPUT specifies which output of P to use."
+ (let* ((pname (package-name p))
+ (version (package-version p))
+ (signing-key (make-signing-key pname)))
+ (package
+ (inherit p)
+ (name (string-append pname "-chromium"))
+ (build-system trivial-build-system)
+ (native-inputs '())
+ (inputs
+ `(("extension" ,(chromium-json->profile-object
+ (crx->chromium-json (make-crx (list p output)
+ signing-key)
+ version)
+ signing-key))))
+ (propagated-inputs '())
+ (outputs '("out"))
+ (arguments
+ '(#:modules ((guix build utils))
+ #:builder
+ (begin
+ (use-modules (guix build utils))
+ (copy-recursively (assoc-ref %build-inputs "extension")
+ (assoc-ref %outputs "out"))))))))
diff --git a/gnu/local.mk b/gnu/local.mk
index 51550e80cb..e847f8c16a 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -657,6 +657,7 @@ GNU_SYSTEM_MODULES = \
%D%/build/accounts.scm \
%D%/build/activation.scm \
%D%/build/bootloader.scm \
+ %D%/build/chromium-extension.scm \
%D%/build/cross-toolchain.scm \
%D%/build/image.scm \
%D%/build/file-systems.scm \
--
2.28.0
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.