abuild/abuild-keygen.in

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#!/bin/sh
# abuild-keygen - generate signing keys
# Copyright (c) 2009 Natanael Copa <ncopa@alpinelinux.org>
#
# Distributed under GPL-2.0-only
#
program_version=@VERSION@
sharedir=${ABUILD_SHAREDIR:-@sharedir@}
SUDO="${SUDO-$(command -v doas || command -v sudo || echo doas)}"
if ! [ -f "$sharedir/functions.sh" ]; then
echo "$sharedir/functions.sh: not found" >&2
exit 1
fi
. "$sharedir/functions.sh"
set -e
# ask for privkey unless non-interactive mode
# returns value in global $privkey
get_privkey_file() {
local emailaddr default_name
emailaddr=${PACKAGER##*<}
emailaddr=${emailaddr%%>*}
# if PACKAGER does not contain a valid email address, then ask git
if [ -z "$emailaddr" ] || [ "${emailaddr##*@}" = "$emailaddr" ]; then
emailaddr=$(${GIT:-git} config --get user.email 2>/dev/null || true)
fi
default_name="${emailaddr:-$USER}-$(printf "%x" $(date +%s))"
privkey="$ABUILD_USERDIR/$default_name.rsa"
if [ -z "$interactive" ]; then
return 0
fi
msg "Generating public/private rsa key pair for abuild"
echo -n "Enter file in which to save the key [$privkey]: "
read line
if [ -n "$line" ]; then
privkey="$line"
fi
}
do_keygen() {
mkdir -p "$ABUILD_USERDIR"
get_privkey_file
pubkey="$privkey.pub"
# generate the private key in a subshell with stricter umask
(
umask 0007
openssl genrsa -out "$privkey" "$numbits"
)
openssl rsa -in "$privkey" -pubout -out "$pubkey"
if [ -n "$install_pubkey" ]; then
msg "Installing $pubkey to /etc/apk/keys..."
$SUDO mkdir -p "${abuild_keygen_install_root}"/etc/apk/keys
$SUDO cp ${interactive:+-i} "$pubkey" "${abuild_keygen_install_root}"/etc/apk/keys/
else
msg ""
msg "You'll need to install $pubkey into "
msg "/etc/apk/keys to be able to install packages and repositories signed with"
msg "$privkey"
fi
if [ -n "$append_config" ]; then
if [ -f "$ABUILD_USERCONF" ]; then
# comment out the existing values
sed -i -e 's/^PACKAGER_PRIVKEY=/\#&/' "$ABUILD_USERCONF"
fi
echo "PACKAGER_PRIVKEY=\"$privkey\"" >> "$ABUILD_USERCONF"
else
msg ""
msg "You might want add following line to $ABUILD_USERCONF:"
msg ""
msg "PACKAGER_PRIVKEY=\"$privkey\""
msg ""
fi
msg ""
msg "Please remember to make a safe backup of your private key:"
msg "$privkey"
msg ""
}
do_kernel_key() {
mkdir -p "$ABUILD_USERDIR"
pem="$ABUILD_USERDIR"/kernel_signing_key.pem
(
umask 0007
# https://www.kernel.org/doc/html/v6.1/admin-guide/module-signing.html#generating-signing-keys
openssl req -verbose -new -nodes -utf8 -sha256 -days 36500 -batch -x509 \
-outform PEM -out "$pem" \
-keyout "$pem" -config - <<-EOF
[ req ]
default_bits = 4096
distinguished_name = req_distinguished_name
prompt = no
string_mask = utf8only
x509_extensions = myexts
[ req_distinguished_name ]
O = alpinelinux.org
CN = Alpine Linux kernel key
#emailAddress = unspecified.user@unspecified.company
[ myexts ]
basicConstraints=critical,CA:FALSE
keyUsage=digitalSignature
subjectKeyIdentifier=hash
authorityKeyIdentifier=keyid
EOF
)
msg "Kernel signing key was created: $pem"
if ! grep -q "^KERNEL_SIGNING_KEY=" "$ABUILD_USERCONF" 2>/dev/null; then
echo "KERNEL_SIGNING_KEY='$pem'" >> "$ABUILD_USERCONF"
fi
msg "KERNEL_SIGNING_KEY='$pem' was added to $ABUILD_USERCONF"
}
usage() {
cat <<-__EOF__
$program $program_version - generate signing keys
Usage: $program [-a|--append] [-i|--install] [-n]
Options:
-a, --append Set PACKAGER_PRIVKEY=<generated key> in
$ABUILD_USERCONF
-i, --install Install public key into /etc/apk/keys using doas
-n Non-interactive. Use defaults
--kernel Generate a key for kernel modules
-b, --numbits [BITS] The size of the private key to generate in bits.
-q, --quiet
-h, --help Show this help
The SUDO variable can be set to pick which tool can be used to
elevate privileges, if it is not set it defaults to doas or sudo if doas
is not found.
__EOF__
}
append_config=
install_pubkey=
interactive=1
numbits=4096
quiet=
kernel_key=
args=$(getopt -o ab:inqh --long append,numbits:,install,quiet,help,kernel -n "$program" -- "$@")
if [ $? -ne 0 ]; then
usage
exit 2
fi
eval set -- "$args"
while true; do
case $1 in
-a|--append) append_config=1;;
-i|--install) install_pubkey=1;;
--kernel) kernel_key=1;;
-n) unset interactive ;;
-b|--numbits) numbits="$2"; shift 1;;
-q|--quiet) quiet=1;; # suppresses msg
-h|--help) usage; exit;;
--) shift; break;;
*) usage >&2; exit 1;; # getopt error
esac
shift
done
if [ $# -ne 0 ]; then
usage >&2
exit 2
fi
if [ -n "$kernel_key" ]; then
do_kernel_key
exit
fi
do_keygen