feat: pin mx host key in keygen

This commit is contained in:
Marek Miklewicz
2026-06-30 19:18:35 +02:00
parent bef92cee77
commit 7d3d458160
4 changed files with 139 additions and 3 deletions
+1 -1
View File
@@ -2,7 +2,7 @@ name=mail-login
id=mail-login
type=user
author=HITME.PL
version=1.0.8
version=1.0.9
active=no
installed=no
user_run_as=root
+92 -1
View File
@@ -5,8 +5,24 @@ KEY_DIR="${MAIL_LOGIN_KEY_DIR:-/usr/local/hitme_plugins/mail-login/secrets}"
KEY_NAME="${MAIL_LOGIN_KEY_NAME:-mx1_ed25519}"
KEY_PATH="$KEY_DIR/$KEY_NAME"
MX_MODE="${MX_LOGIN_MODE:-1}"
SETTINGS_FILE="${MAIL_LOGIN_SETTINGS_FILE:-/usr/local/directadmin/plugins/mail-login/plugin-settings.conf}"
HELPER_COMMAND="${MAIL_LOGIN_HELPER_COMMAND:-/usr/local/hitme_plugins/mail-login-helper/bin/create-login-url}"
config_value() {
key="$1"
if [ ! -f "$SETTINGS_FILE" ]; then
return 0
fi
awk -F= -v key="$key" '
$1 == key {
value = substr($0, index($0, "=") + 1)
gsub(/^[ \t]+|[ \t]+$/, "", value)
print value
exit
}
' "$SETTINGS_FILE"
}
derive_servername() {
if [ -n "${SERVERNAME:-}" ]; then
printf '%s' "$SERVERNAME"
@@ -45,12 +61,64 @@ detect_source_ip() {
return 1
}
pin_mx_host_key() {
if [ -z "$MX_HOST" ]; then
HOST_KEY_STATUS="skipped: MAIL_LOGIN_SSH_HOST is not configured"
return
fi
if ! command -v ssh-keyscan >/dev/null 2>&1; then
HOST_KEY_STATUS="skipped: ssh-keyscan is not available"
return
fi
known_dir="$(dirname "$KNOWN_HOSTS")"
mkdir -p "$known_dir"
chmod 700 "$known_dir"
touch "$KNOWN_HOSTS"
chmod 600 "$KNOWN_HOSTS"
lookup="$MX_HOST"
if [ "$MX_PORT" != "22" ]; then
lookup="[$MX_HOST]:$MX_PORT"
fi
if ssh-keygen -F "$lookup" -f "$KNOWN_HOSTS" >/dev/null 2>&1; then
HOST_KEY_STATUS="already present for $lookup"
return
fi
tmp="$KNOWN_HOSTS.$$"
if ssh-keyscan -T "$SCAN_TIMEOUT" -p "$MX_PORT" -t ed25519 "$MX_HOST" > "$tmp" 2>/dev/null && [ -s "$tmp" ]; then
cat "$tmp" >> "$KNOWN_HOSTS"
chmod 600 "$KNOWN_HOSTS"
HOST_KEY_FINGERPRINT="$(ssh-keygen -lf "$tmp" 2>/dev/null | head -n 1 || true)"
HOST_KEY_STATUS="pinned $lookup"
rm -f "$tmp"
return
fi
rm -f "$tmp"
HOST_KEY_STATUS="failed: cannot fetch ED25519 host key for $MX_HOST:$MX_PORT"
}
SERVER_LABEL="$(clean_label "$(derive_servername)")"
if [ -z "$SERVER_LABEL" ]; then
echo "Cannot determine SERVERNAME" >&2
exit 1
fi
CONFIG_SSH_HOST="$(config_value MAIL_LOGIN_SSH_HOST || true)"
CONFIG_SSH_PORT="$(config_value MAIL_LOGIN_SSH_PORT || true)"
CONFIG_KNOWN_HOSTS="$(config_value MAIL_LOGIN_SSH_KNOWN_HOSTS || true)"
CONFIG_SCAN_TIMEOUT="$(config_value MAIL_LOGIN_CONNECT_TIMEOUT_SECONDS || true)"
MX_HOST="${MAIL_LOGIN_SSH_HOST:-$CONFIG_SSH_HOST}"
MX_PORT="${MAIL_LOGIN_SSH_PORT:-$CONFIG_SSH_PORT}"
MX_PORT="${MX_PORT:-22}"
KNOWN_HOSTS="${MAIL_LOGIN_SSH_KNOWN_HOSTS:-$CONFIG_KNOWN_HOSTS}"
KNOWN_HOSTS="${KNOWN_HOSTS:-$KEY_DIR/known_hosts}"
SCAN_TIMEOUT="${MAIL_LOGIN_CONNECT_TIMEOUT_SECONDS:-$CONFIG_SCAN_TIMEOUT}"
SCAN_TIMEOUT="${SCAN_TIMEOUT:-5}"
case "$MX_MODE" in
1|2) ;;
*)
@@ -59,6 +127,20 @@ case "$MX_MODE" in
;;
esac
case "$MX_PORT" in
*[!0-9]*|'')
echo "MAIL_LOGIN_SSH_PORT must be numeric" >&2
exit 1
;;
esac
case "$SCAN_TIMEOUT" in
*[!0-9]*|'')
echo "MAIL_LOGIN_CONNECT_TIMEOUT_SECONDS must be numeric" >&2
exit 1
;;
esac
SOURCE_IP="$(detect_source_ip || true)"
case "$SOURCE_IP" in
*[!A-Za-z0-9:./_-]*|'')
@@ -82,6 +164,10 @@ fi
chmod 600 "$KEY_PATH"
chmod 644 "$KEY_PATH.pub"
HOST_KEY_STATUS=""
HOST_KEY_FINGERPRINT=""
pin_mx_host_key
PUB_KEY="$(cat "$KEY_PATH.pub")"
BASE_OPTIONS="from=\"$SOURCE_IP\",restrict,no-agent-forwarding,no-port-forwarding,no-X11-forwarding,no-pty"
@@ -102,7 +188,12 @@ $KEY_PATH.pub
Set this in plugin-settings.conf:
MAIL_LOGIN_SSH_IDENTITY=$KEY_PATH
MAIL_LOGIN_SSH_KNOWN_HOSTS=/root/.ssh/known_hosts
MAIL_LOGIN_SSH_KNOWN_HOSTS=$KNOWN_HOSTS
MX known_hosts:
$KNOWN_HOSTS
Pinned MX host key: $HOST_KEY_STATUS
${HOST_KEY_FINGERPRINT}
Add this line to /root/.ssh/authorized_keys on mx1:
$AUTH_OPTIONS $PUB_KEY $COMMENT
+45
View File
@@ -47,6 +47,51 @@ test('keygen script detects source ip without parameters', function (): void {
assert_not_contains('SOURCE_SERVER_PUBLIC_IP', $output);
});
test('keygen script pins mx host key from plugin settings', function (): void {
$keyDir = TEST_TMP . '/keys-known-hosts';
$knownHosts = TEST_TMP . '/known-hosts/known_hosts';
$settings = TEST_TMP . '/plugin-settings.conf';
$binDir = TEST_TMP . '/fake-scan-bin';
$hostKey = TEST_TMP . '/mx-host-ed25519';
mkdir($binDir, 0700, true);
exec(sprintf('ssh-keygen -q -t ed25519 -N "" -f %s -C %s', escapeshellarg($hostKey), escapeshellarg('mx1.test')), $keygenOut, $keygenCode);
assert_same(0, $keygenCode, implode("\n", $keygenOut));
$pub = trim((string)file_get_contents($hostKey . '.pub'));
$parts = explode(' ', $pub);
$knownHostLine = '[mx1.test]:10022 ' . $parts[0] . ' ' . $parts[1];
test_write($settings, implode("\n", [
'MAIL_LOGIN_SSH_HOST=mx1.test',
'MAIL_LOGIN_SSH_PORT=10022',
'MAIL_LOGIN_SSH_KNOWN_HOSTS=' . $knownHosts,
'MAIL_LOGIN_CONNECT_TIMEOUT_SECONDS=5',
'',
]));
test_write($binDir . '/ssh-keyscan', "#!/bin/sh\nif [ \"$1 $2 $3 $4 $5 $6 $7\" = '-T 5 -p 10022 -t ed25519 mx1.test' ]; then cat <<'EOF'\n$knownHostLine\nEOF\nexit 0\nfi\nexit 1\n");
chmod($binDir . '/ssh-keyscan', 0755);
$script = PLUGIN_ROOT . '/scripts/keygen.sh';
$cmd = sprintf(
'PATH=%s:$PATH MAIL_LOGIN_SETTINGS_FILE=%s MAIL_LOGIN_KEY_DIR=%s SERVERNAME=%s SOURCE_IP=%s %s',
escapeshellarg($binDir),
escapeshellarg($settings),
escapeshellarg($keyDir),
escapeshellarg('h4'),
escapeshellarg('203.0.113.10'),
escapeshellarg($script)
);
exec($cmd, $out, $code);
assert_same(0, $code, implode("\n", $out));
assert_true(is_file($knownHosts));
assert_contains('[mx1.test]:10022', file_get_contents($knownHosts) ?: '');
$output = implode("\n", $out);
assert_contains('MAIL_LOGIN_SSH_KNOWN_HOSTS=' . $knownHosts, $output);
assert_contains('Pinned MX host key:', $output);
});
test('keygen script prints helper forced command line when mx login mode is helper', function (): void {
$keyDir = TEST_TMP . '/keys-helper';
$script = PLUGIN_ROOT . '/scripts/keygen.sh';
+1 -1
View File
@@ -8,7 +8,7 @@ test('plugin metadata and packaging docs match project rules', function (): void
assert_contains('name=mail-login', $conf);
assert_contains('id=mail-login', $conf);
assert_contains('type=user', $conf);
assert_contains('version=1.0.8', $conf);
assert_contains('version=1.0.9', $conf);
assert_contains('user_run_as=root', $conf);
assert_contains('/Users/marek/GPT/ChatGPT/da_plugins/mail-login/src', $packing);
assert_contains('/Users/marek/GPT/ChatGPT/da_plugins/mail-login/archives/X.Y.Z/mail-login.tar.gz', $packing);