create-server

#!/usr/bin/env bash
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

# Derek Moore <derek.moore@gmail.com>
# Christian Göttsche <cgzones@googlemail.com>

set -eu
set -o pipefail

umask 0077

BIN_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
source "${BIN_DIR}/functions"
source "${BIN_DIR}/defaults.conf"

usage() {
    echo "Usage: $0 -s SHORT_NAME -a ALT_NAME [-a ALT_NAME2]... [-i ALT_IP1]..."
    echo "Issues a server certificate for SHORT_NAME"
    echo
    echo "Options:"
    echo "    -s SHORT_NAME   Server hostname (commonName) for the new cert"
    echo "    -a ALT_NAME     One (or more) subjectAltNames for the new cert"
    echo "    -i ALT_IP       One (or more) IP addresses as SANs for the new cert"
    echo
}

if [ ! -f ca/ca.crt ]; then
    echo -e "$ERR Must be run inside a CA directory!"
    exit 2
fi

SERVER_NAME=
ALT_NAME=

while getopts s:a:i:h FLAG; do
    case $FLAG in
        h) echo -e -n "$SUCC " && usage && exit 0
           ;;
        s) SERVER_NAME="${OPTARG}"
           ;;
        a) if [ -z "${ALT_NAME}" ]; then
               ALT_NAME="DNS:${OPTARG}"
           else
               ALT_NAME="${ALT_NAME}, DNS:${OPTARG}"
           fi
           ;;
        i) if [ -z "${ALT_NAME}" ]; then
               ALT_NAME="IP:${OPTARG}"
           else
               ALT_NAME="${ALT_NAME}, IP:${OPTARG}"
           fi
           ;;
        *) echo -e -n "$ERR " && usage && exit 2
           ;;
    esac
done

if [ $OPTIND -le $# ]; then
    echo -e -n "$ERR " && usage && exit 2
elif [ "$SERVER_NAME" = "" ]; then
    echo -e -n "$ERR " && usage && exit 2
elif [ "$ALT_NAME" = "" ]; then
    echo -e -n "$ERR " && usage && exit 2
fi

# Sanitize the commonName to make it suitable for use in filenames
SAFE_NAME=$(echo "$SERVER_NAME" | sed 's/\*/star/g' | sed 's/[^A-Za-z0-9-]/-/g')

echo -e "$NOTE Creating new SSL server certificate for:" >&2
echo -e "$NOTE commonName       $SERVER_NAME" >&2
echo -e "$NOTE subjectAltName   $ALT_NAME" >&2

pushd "$BIN_DIR/.." > /dev/null

if [ -d "certs/server/$SAFE_NAME" ]; then
    echo -e "$ERR Configuration already exists for '$SERVER_NAME', exiting." >&2
    exit 1
fi


echo
if [ -n "$CA_ENABLE_ENGINE" ]; then
    echo -e "$NOTE Your CA key is on PKCS11 device, enter PIN." >&2
fi
PASS=`ask -s "$INPUT Enter passphrase for signing CA key: " CA_SIGN_PASS_DEFAULT "${SIGN_PASS:-""}"`
echo >&2
export CA_PASS="${PASS}"

openssl_engine_cmd='
    -engine pkcs11 
    -inform engine
    -in pkcs11:object=SIGN%20key'
openssl rsa \
            ${CA_ENABLE_ENGINE:+$openssl_engine_cmd} \
            $( [ -z $CA_ENABLE_ENGINE ] && echo "-check -in ca/private/ca.key") \
            -noout \
            -passin env:CA_PASS

trap 'rm -Rf "certs/server/$SAFE_NAME"' 0
mkdir -p "certs/server/$SAFE_NAME/ssh"

# Generate the server openssl config
export CA_HOSTNAME="${SERVER_NAME}"
export SAN="${ALT_NAME}"
ask_server_cert_questions
template "${BIN_DIR}/templates/server.tpl" "certs/server/$SAFE_NAME/$SAFE_NAME.conf"

echo -e "$NOTE Usually a server key will not be on a pkcs11 device." >&2
SURE=`ask "$INPUT Create csr on pkcs11 device? (key must be in \"PIV AUTH key\" or 9a) [y/N]: " CA_USE_PKCS11 "N"`
if [ "${SURE}" != "y" ] && [ "${SURE}" != "Y" ]; then
    ENABLE_ENGINE=
else
    ENABLE_ENGINE=1
    init_slot 9a "certs/server/$SAFE_NAME/$SAFE_NAME.pub" "pkcs11:object=PIV%20AUTH%20key"
fi

echo -e "$NOTE Creating the server key and csr" >&2

# Create the sever key and csr
openssl_engine_cmd='
    -engine pkcs11 
    -keyform engine
    -key pkcs11:object=PIV%20AUTH%20key'
openssl req -new -batch \
            ${ENABLE_ENGINE:+$openssl_engine_cmd} \
            -config "certs/server/$SAFE_NAME/$SAFE_NAME.conf" \
            -out "certs/server/$SAFE_NAME/$SAFE_NAME.csr" \
            $( [ -z $ENABLE_ENGINE ] && echo "
            -nodes
            -keyout certs/server/$SAFE_NAME/$SAFE_NAME.key")

openssl_engine_cmd='
    -engine pkcs11 
    -inform engine
    -in pkcs11:object=PIV%20AUTH%20key'
openssl rsa \
            ${ENABLE_ENGINE:+$openssl_engine_cmd} \
            $( [ -z $ENABLE_ENGINE ] && echo "-check -in certs/server/$SAFE_NAME/$SAFE_NAME.key") \
            -noout

echo -e "$NOTE Example known_hosts: @cert-authority *.example.com ca.ssh-cert.pub" >&2
echo -e "$NOTE Example sshd_config: HostCertificate $SAFE_NAME.ssh-cert.pub" >&2
echo -e "$NOTE Example sshd_config: TrustedUserCAKeys ca.ssh.pub" >&2
echo -e "$NOTE Example sshd_config: RevokedKeys revoked-keys" >&2

if [ -z "$ENABLE_ENGINE" ]; then
    chmod 0400 "certs/server/$SAFE_NAME/$SAFE_NAME.key"
    ln -s ../"$SAFE_NAME".key "certs/server/$SAFE_NAME/ssh/$SAFE_NAME.ssh"
    openssl rsa -in "certs/server/$SAFE_NAME/$SAFE_NAME.key" \
        -pubout -out "certs/server/$SAFE_NAME/$SAFE_NAME.pub"
fi
ssh-keygen -f "certs/server/$SAFE_NAME/$SAFE_NAME.pub" -i -mPKCS8 \
        | awk "{printf \$0;print \" ${SAFE_NAME}\"}" > "certs/server/$SAFE_NAME/ssh/$SAFE_NAME.ssh.pub"

echo -e "$NOTE Creating the server certificate" >&2

# Create the server certificate
openssl_engine_cmd="\
    -engine pkcs11 \
    -keyform engine \
    -keyfile pkcs11:object=SIGN%20key"
openssl ca -batch -notext \
           ${CA_ENABLE_ENGINE:+$openssl_engine_cmd} \
           -config ca/ca.conf \
           -in "certs/server/$SAFE_NAME/$SAFE_NAME.csr" \
           -out "certs/server/$SAFE_NAME/$SAFE_NAME.crt" \
           -extensions server_ext \
           -passin env:CA_PASS

if [[ -n "$ENABLE_ENGINE" ]]; then
    replace_crt 9a certs/server/"$SAFE_NAME"/"$SAFE_NAME".crt
fi

echo -e "$NOTE Verifying certificate/key pair" >&2

openssl_engine_cmd="\
    -engine pkcs11 \
    -inform engine \
    -in pkcs11:object=PIV%20AUTH%20key"
key_mod=$(openssl rsa \
    ${ENABLE_ENGINE:+$openssl_engine_cmd} -noout -modulus \
    $( [ -z $ENABLE_ENGINE ] && echo "-in certs/server/$SAFE_NAME/$SAFE_NAME.key")
)

cert_mod=$(openssl x509 -noout -modulus -in "certs/server/$SAFE_NAME/$SAFE_NAME.crt")

if [ ! "$key_mod" = "$cert_mod" ];then
    echo -e "$ERR Certificate/Key pair invalid:"
    echo -e "$ERR     <>$cert_mod<>"
    echo -e "$ERR     <>$key_mod<>"
    echo
    exit 2
fi

echo -e "$NOTE Verifying trusted chain"

openssl verify -CAfile ca/chain.pem "certs/server/$SAFE_NAME/$SAFE_NAME.crt"

popd > /dev/null

unset CA_PASS

trap 0

echo -e "$SUCC Server certificate for '${SERVER_NAME}' created."