summaryrefslogtreecommitdiff
blob: d16181f3bf0a7f607913d8b2404bcdb3585e5ecc (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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
# Copyright 2020 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2

# @ECLASS: verify-sig.eclass
# @MAINTAINER:
# Michał Górny <mgorny@gentoo.org>
# @SUPPORTED_EAPIS: 7
# @BLURB: Eclass to verify upstream signatures on distfiles
# @DESCRIPTION:
# verify-sig eclass provides a streamlined approach to verifying
# upstream signatures on distfiles.  Its primary purpose is to permit
# developers to easily verify signatures while bumping packages.
# The eclass removes the risk of developer forgetting to perform
# the verification, or performing it incorrectly, e.g. due to additional
# keys in the local keyring.  It also permits users to verify
# the developer's work.
#
# To use the eclass, start by packaging the upstream's key
# as app-crypt/openpgp-keys-*.  Then inherit the eclass, add detached
# signatures to SRC_URI and set VERIFY_SIG_OPENPGP_KEY_PATH.  The eclass
# provides verify-sig USE flag to toggle the verification.
#
# Example use:
# @CODE
# inherit verify-sig
#
# SRC_URI="https://example.org/${P}.tar.gz
#   verify-sig? ( https://example.org/${P}.tar.gz.sig )"
# BDEPEND="
#   verify-sig? ( app-crypt/openpgp-keys-example )"
#
# VERIFY_SIG_OPENPGP_KEY_PATH=/usr/share/openpgp-keys/example.asc
# @CODE

case "${EAPI:-0}" in
	0|1|2|3|4|5|6)
		die "Unsupported EAPI=${EAPI} (obsolete) for ${ECLASS}"
		;;
	7)
		;;
	*)
		die "Unsupported EAPI=${EAPI} (unknown) for ${ECLASS}"
		;;
esac

EXPORT_FUNCTIONS src_unpack

if [[ ! ${_VERIFY_SIG_ECLASS} ]]; then

IUSE="verify-sig"

BDEPEND="
	verify-sig? (
		app-crypt/gnupg
		>=app-portage/gemato-16
	)"

# @ECLASS-VARIABLE: VERIFY_SIG_OPENPGP_KEY_PATH
# @DEFAULT_UNSET
# @DESCRIPTION:
# Path to key bundle used to perform the verification.  This is required
# when using default src_unpack.  Alternatively, the key path can be
# passed directly to the verification functions.

# @ECLASS-VARIABLE: VERIFY_SIG_OPENPGP_KEYSERVER
# @DEFAULT_UNSET
# @DESCRIPTION:
# Keyserver used to refresh keys.  If not specified, the keyserver
# preference from the key will be respected.  If no preference
# is specified by the key, the GnuPG default will be used.

# @ECLASS-VARIABLE: VERIFY_SIG_OPENPGP_KEY_REFRESH
# @USER_VARIABLE
# @DESCRIPTION:
# Attempt to refresh keys via WKD/keyserver.  Set it to "yes"
# in make.conf to enable.  Note that this requires working Internet
# connection.
: ${VERIFY_SIG_OPENPGP_KEY_REFRESH:=no}

# @FUNCTION: verify-sig_verify_detached
# @USAGE: <file> <sig-file> [<key-file>]
# @DESCRIPTION:
# Read the detached signature from <sig-file> and verify <file> against
# it.  <key-file> can either be passed directly, or it defaults
# to VERIFY_SIG_OPENPGP_KEY_PATH.  The function dies if verification
# fails.
verify-sig_verify_detached() {
	local file=${1}
	local sig=${2}
	local key=${3:-${VERIFY_SIG_OPENPGP_KEY_PATH}}

	[[ -n ${key} ]] ||
		die "${FUNCNAME}: no key passed and VERIFY_SIG_OPENPGP_KEY_PATH unset"

	local extra_args=()
	[[ ${VERIFY_SIG_OPENPGP_KEY_REFRESH} == yes ]] || extra_args+=( -R )
	[[ -n ${VERIFY_SIG_OPENPGP_KEYSERVER+1} ]] && extra_args+=(
		--keyserver "${VERIFY_SIG_OPENPGP_KEYSERVER}"
	)

	# GPG upstream knows better than to follow the spec, so we can't
	# override this directory.  However, there is a clean fallback
	# to GNUPGHOME.
	addpredict /run/user

	local filename=${file##*/}
	[[ ${file} == - ]] && filename='(stdin)'
	einfo "Verifying ${filename} ..."
	gemato gpg-wrap -K "${key}" "${extra_args[@]}" -- \
		gpg --verify "${sig}" "${file}" ||
		die "PGP signature verification failed"
}

# @FUNCTION: verify-sig_src_unpack
# @DESCRIPTION:
# Default src_unpack override that verifies signatures for all
# distfiles if 'verify-sig' flag is enabled.  The function dies if any
# of the signatures fails to verify or if any distfiles are not signed.
# Please write src_unpack() yourself if you need to perform partial
# verification.
verify-sig_src_unpack() {
	if use verify-sig; then
		local f suffix found
		local distfiles=() signatures=() nosigfound=() straysigs=()

		# find all distfiles and signatures, and combine them
		for f in ${A}; do
			found=
			for suffix in .asc .sig; do
				if [[ ${f} == *${suffix} ]]; then
					signatures+=( "${f}" )
					found=sig
					break
				else
					if has "${f}${suffix}" ${A}; then
						distfiles+=( "${f}" )
						found=dist+sig
						break
					fi
				fi
			done
			if [[ ! ${found} ]]; then
				nosigfound+=( "${f}" )
			fi
		done

		# check if all distfiles are signed
		if [[ ${#nosigfound[@]} -gt 0 ]]; then
			eerror "The following distfiles lack detached signatures:"
			for f in "${nosigfound[@]}"; do
				eerror "  ${f}"
			done
			die "Unsigned distfiles found"
		fi

		# check if there are no stray signatures
		for f in "${signatures[@]}"; do
			if ! has "${f%.*}" "${distfiles[@]}"; then
				straysigs+=( "${f}" )
			fi
		done
		if [[ ${#straysigs[@]} -gt 0 ]]; then
			eerror "The following signatures do not match any distfiles:"
			for f in "${straysigs[@]}"; do
				eerror "  ${f}"
			done
			die "Unused signatures found"
		fi

		# now perform the verification
		for f in "${signatures[@]}"; do
			verify-sig_verify_detached \
				"${DISTDIR}/${f%.*}" "${DISTDIR}/${f}"
		done
	fi

	# finally, unpack the distfiles
	default_src_unpack
}

_VERIFY_SIG_ECLASS=1
fi