blob: 8ca5251957fd187e3d303ff1c3674e7d03fc53b8 (
about) (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2020, 2021 Marius Bakke <marius@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 (guix gexp)
#:use-module (guix packages)
#: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."
(computed-file
(string-append seed "-signing-key.pem")
(with-extensions (list guile-gcrypt)
#~(begin
(use-modules (gcrypt base16) (gcrypt hash) (ice-9 iconv))
(let* ((sha256sum (bytevector->base16-string
(sha256 (string->bytevector #$seed "UTF-8"))))
;; certtool.c wants a 56 byte seed for a 2048 bit key.
(key-size 2048)
(normalized-seed (string-take sha256sum 56)))
(system* #$(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 key-size))
(string-append "--seed=" normalized-seed)
"--outfile" #$output))))
#:local-build? #t))
(define* (make-crx signing-key package #:optional (package-output "out"))
"Create a signed \".crx\" file from the unpacked Chromium extension residing
in PACKAGE-OUTPUT of PACKAGE. The extension will be signed with SIGNING-KEY."
(define name (package-name package))
(define version (package-version package))
(computed-file
(string-append name "-" version ".crx")
(with-imported-modules '((guix build utils))
#~(begin
;; This is not great. We pull Xorg and Chromium just to Zip and
;; sign an extension. This should be implemented with something
;; lighter. (TODO: where is the CRXv3 documentation..?)
(use-modules (guix build utils))
(let ((chromium #$(file-append ungoogled-chromium "/bin/chromium"))
(xvfb #$(file-append xorg-server "/bin/Xvfb"))
(packdir (string-append (getcwd) "/extension")))
(mkdir packdir)
(copy-recursively (ungexp package package-output) packdir
;; Ensure consistent file modification times.
#:keep-mtime? #t)
(system (string-append xvfb " :1 &"))
(setenv "DISPLAY" ":1")
(sleep 2) ;give Xorg some time to initialize...
(invoke chromium
"--user-data-dir=chromium-profile"
(string-append "--pack-extension=" packdir)
(string-append "--pack-extension-key=" #$signing-key))
(copy-file (string-append packdir ".crx") #$output))))
#:local-build? #t))
(define (crx->chromium-json crx version)
"Return a derivation that creates a Chromium JSON settings file for the
extension given as CRX. VERSION is used to signify the CRX version, and
must match the version listed in the extension manifest.json."
;; See chrome/browser/extensions/external_provider_impl.cc and
;; extensions/common/extension.h for documentation on the JSON format.
(computed-file "extension.json"
#~(call-with-output-file #$output
(lambda (port)
(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" #$output
"--outder")
#:local-build? #t))
(define (file-sha256sum file)
(with-extensions (list guile-gcrypt)
#~(begin
(use-modules (gcrypt base16) (gcrypt hash))
(bytevector->base16-string (file-sha256 #$file)))))
(define* (make-chromium-extension pkg #:optional (pkg-output "out"))
"Create a Chromium extension from package PKG and return a package that,
when installed, will make the extension contained in PKG available as a
Chromium browser extension. PKG-OUTPUT specifies which output of PKG to use."
(let* ((name (package-name pkg))
(version (package-version pkg))
(private-key (make-signing-key name))
(public-key (signing-key->public-der private-key))
(checksum (file-sha256sum public-key))
(crx (make-crx private-key pkg pkg-output))
(json (crx->chromium-json crx version)))
(package
(inherit pkg)
(name (string-append name "-chromium"))
(source #f)
(native-inputs '())
(inputs '())
(propagated-inputs '())
(outputs '("out"))
(build-system trivial-build-system)
(arguments
(list #:modules '((guix build utils))
#:builder
#~(begin
(use-modules (guix build utils))
(define (base16-char->chromium-base16 char)
;; Translate CHAR, a hexadecimal character, to a Chromium-style
;; representation using the letters a-p (where a=0, p=15).
(string-ref "abcdefghijklmnop"
(string-index "0123456789abcdef" char)))
(let ((file-name (string-map base16-char->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")))))))))
|
