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| -rw-r--r-- | conf/postfix-tls-script | 1152 |
1 files changed, 1152 insertions, 0 deletions
diff --git a/conf/postfix-tls-script b/conf/postfix-tls-script new file mode 100644 index 0000000..997e9c5 --- /dev/null +++ b/conf/postfix-tls-script @@ -0,0 +1,1152 @@ +#!/bin/sh + +#++ +# NAME +# postfix-tls 1 +# SUMMARY +# Postfix TLS management +# SYNOPSIS +# \fBpostfix tls\fR \fIsubcommand\fR +# DESCRIPTION +# The "\fBpostfix tls \fIsubcommand\fR" feature enables +# opportunistic TLS in the Postfix SMTP client or server, and +# manages Postfix SMTP server private keys and certificates. +# +# The following subcommands are available: +# .IP "\fBenable-client\fR [\fB-r \fIrandsource\fR]" +# Enable opportunistic TLS in the Postfix SMTP client, if all +# SMTP client TLS settings are at their default values. +# Otherwise, suggest parameter settings without making any +# changes. +# .sp +# Specify \fIrandsource\fR to update the value of the +# \fBtls_random_source\fR configuration parameter (typically, +# /dev/urandom). Prepend \fBdev:\fR to device paths or +# \fBegd:\fR to EGD socket paths. +# .sp +# See also the \fBall-default-client\fR subcommand. +# .IP "\fBenable-server\fR [\fB-r \fIrandsource\fR] [\fB-a \fIalgorithm\fR] [\fB-b \fIbits\fR] [\fIhostname\fB...\fR]" +# Create a new private key and self-signed server certificate +# and enable opportunistic TLS in the Postfix SMTP server, +# if all SMTP server TLS settings are at their default values. +# Otherwise, suggest parameter settings without making any +# changes. +# .sp +# The \fIrandsource\fR parameter is as with \fBenable-client\fR +# above, and the remaining options are as with \fBnew-server-key\fR +# below. +# .sp +# See also the \fBall-default-server\fR subcommand. +# .IP "\fBnew-server-key\fR [\fB-a \fIalgorithm\fR] [\fB-b \fIbits\fR] [\fIhostname\fB...\fR]" +# Create a new private key and self-signed server certificate, +# but do not deploy them. Log and display commands to deploy +# the new key and corresponding certificate. Also log and +# display commands to output a corresponding CSR or TLSA +# records which may be needed to obtain a CA certificate or +# to update DNS before the new key can be deployed. +# .sp +# The \fIalgorithm\fR defaults to \fBrsa\fR, and \fIbits\fR +# defaults to 2048. If you choose the \fBecdsa\fR \fIalgorithm\fR +# then \fIbits\fR will be an EC curve name (by default +# \fBsecp256r1\fR, also known as prime256v1). Curves other +# than \fBsecp256r1\fR, \fBsecp384r1\fR or \fBsecp521r1\fR +# are unlikely to be widely interoperable. When generating +# EC keys, use one of these three. DSA keys are obsolete and +# are not supported. +# .sp +# Note: ECDSA support requires OpenSSL 1.0.0 or later and may +# not be available on your system. Not all client systems +# will support ECDSA, so you'll generally want to deploy both +# RSA and ECDSA certificates to make use of ECDSA with +# compatible clients and RSA with the rest. If you want to +# deploy certificate chains with intermediate CAs for both +# RSA and ECDSA, you'll want at least OpenSSL 1.0.2, as earlier +# versions may not handle multiple chain files correctly. +# .sp +# The first \fIhostname\fR argument will be the \fBCommonName\fR +# of both the subject and issuer of the self-signed certificate. +# It, and any additional \fIhostname\fR arguments, will also +# be listed as DNS alternative names in the certificate. If +# no \fIhostname\fR is provided the value of the \fBmyhostname\fR +# main.cf parameter will be used. +# .sp +# For RSA, the generated private key and certificate files +# are named \fBkey-\fIyyyymmdd-hhmmss\fB.pem\fR and +# \fBcert-\fIyyyymmdd-hhmmss\fB.pem\fR, where \fIyyyymmdd\fR +# is the calendar date and \fIhhmmss\fR is the time of day +# in UTC. For ECDSA, the file names start with \fBeckey-\fR +# and \fBeccert-\fR instead of \fBkey-\fR and \fBcert-\fR +# respectively. +# .sp +# Before deploying the new key and certificate with DANE, +# update the DNS with new DANE TLSA records, then wait for +# secondary nameservers to update and then for stale records +# in remote DNS caches to expire. +# .sp +# Before deploying a new CA certificate make sure to include +# all the required intermediate issuing CA certificates in +# the certificate chain file. The server certificate must +# be the first certificate in the chain file. Overwrite and +# deploy the file with the original self-signed certificate +# that was generated together with the key. +# .IP "\fBnew-server-cert\fR [\fB-a \fIalgorithm\fR] [\fB-b \fIbits\fR] [\fIhostname\fB...\fR]" +# This is just like \fBnew-server-key\fR except that, rather +# than generating a new private key, any currently deployed +# private key is copied to the new key file. Thus if you're +# publishing DANE TLSA "3 1 1" or "3 1 2" records, there is +# no need to update DNS records. The \fIalgorithm\fR and +# \fIbits\fR arguments are used only if no key of the same +# algorithm is already configured. +# .sp +# This command is rarely needed, because the self-signed +# certificates generated have a 100-year nominal expiration +# time. The underlying public key algorithms may well be +# obsoleted by quantum computers long before then. +# .sp +# The most plausible reason for using this command is when +# the system hostname changes, and you'd like the name in the +# certificate to match the new hostname (not required for +# DANE "3 1 1", but some needlessly picky non-DANE opportunistic +# TLS clients may log warnings or even refuse to communicate). +# .IP "\fBdeploy-server-cert \fIcertfile\fB \fIkeyfile\fR" +# This subcommand deploys the certificates in \fIcertfile\fR +# and private key in \fIkeyfile\fR (which are typically +# generated by the commands above, which will also log and +# display the full command needed to deploy the generated key +# and certificate). After the new certificate and key are +# deployed any obsolete keys and certificates may be removed +# by hand. The \fIkeyfile\fR and \fIcertfile\fR filenames +# may be relative to the Postfix configuration directory. +# .IP "\fBoutput-server-csr\fR [\fB-k \fIkeyfile\fR] [\fIhostname\fB...\fR]" +# Write to stdout a certificate signing request (CSR) for the +# specified \fIkeyfile\fR. +# .sp +# Instead of an absolute pathname or a pathname relative to +# $config_directory, \fIkeyfile\fR may specify one of the +# supported key algorithm names (see "\fBpostconf -T +# public-key-algorithms\fR"). In that case, the corresponding +# setting from main.cf is used to locate the \fIkeyfile\fR. +# The default \fIkeyfile\fR value is \fBrsa\fR. +# .sp +# Zero or more \fIhostname\fR values can be specified. The +# default \fIhostname\fR is the value of \fBmyhostname\fR +# main.cf parameter. +# .IP "\fBoutput-server-tlsa\fR [\fB-h \fIhostname\fR] [\fIkeyfile\fB...\fR]" +# Write to stdout a DANE TLSA RRset suitable for a port 25 +# SMTP server on host \fIhostname\fR with keys from any of +# the specified \fIkeyfile\fR values. The default \fIhostname\fR +# is the value of the \fBmyhostname\fR main.cf parameter. +# .sp +# Instead of absolute pathnames or pathnames relative to +# $config_directory, the \fIkeyfile\fR list may specify +# names of supported public key algorithms (see "\fBpostconf +# -T public-key-algorithms\fR"). In that case, the actual +# \fIkeyfile\fR list uses the values of the corresponding +# Postfix server TLS key file parameters. If a parameter +# value is empty or equal to \fBnone\fR, then no TLSA record +# is output for that algorithm. +# .sp +# The default \fIkeyfile\fR list consists of the two supported +# algorithms \fBrsa\fR and \fBecdsa\fR. +# AUXILIARY COMMANDS +# .IP "\fBall-default-client\fR" +# Exit with status 0 (success) if all SMTP client TLS settings are +# at their default values. Otherwise, exit with a non-zero status. +# This is typically used as follows: +# .sp +# \fBpostfix tls all-default-client && +# postfix tls enable-client\fR +# .IP "\fBall-default-server\fR" +# Exit with status 0 (success) if all SMTP server TLS settings are +# at their default values. Otherwise, exit with a non-zero status. +# This is typically used as follows: +# .sp +# \fBpostfix tls all-default-server && +# postfix tls enable-server\fR +# CONFIGURATION PARAMETERS +# .ad +# .fi +# The "\fBpostfix tls \fIsubcommand\fR" feature reads +# or updates the following configuration parameters. +# .IP "\fBcommand_directory (see 'postconf -d' output)\fR" +# The location of all postfix administrative commands. +# .IP "\fBconfig_directory (see 'postconf -d' output)\fR" +# The default location of the Postfix main.cf and master.cf +# configuration files. +# .IP "\fBopenssl_path (openssl)\fR" +# The location of the OpenSSL command line program \fBopenssl\fR(1). +# .IP "\fBsmtp_tls_loglevel (0)\fR" +# Enable additional Postfix SMTP client logging of TLS activity. +# .IP "\fBsmtp_tls_security_level (empty)\fR" +# The default SMTP TLS security level for the Postfix SMTP client. +# .IP "\fBsmtp_tls_session_cache_database (empty)\fR" +# Name of the file containing the optional Postfix SMTP client +# TLS session cache. +# .IP "\fBsmtpd_tls_cert_file (empty)\fR" +# File with the Postfix SMTP server RSA certificate in PEM format. +# .IP "\fBsmtpd_tls_eccert_file (empty)\fR" +# File with the Postfix SMTP server ECDSA certificate in PEM format. +# .IP "\fBsmtpd_tls_eckey_file ($smtpd_tls_eccert_file)\fR" +# File with the Postfix SMTP server ECDSA private key in PEM format. +# .IP "\fBsmtpd_tls_key_file ($smtpd_tls_cert_file)\fR" +# File with the Postfix SMTP server RSA private key in PEM format. +# .IP "\fBsmtpd_tls_loglevel (0)\fR" +# Enable additional Postfix SMTP server logging of TLS activity. +# .IP "\fBsmtpd_tls_received_header (no)\fR" +# Request that the Postfix SMTP server produces Received: message +# headers that include information about the protocol and cipher used, +# as well as the remote SMTP client CommonName and client certificate issuer +# CommonName. +# .IP "\fBsmtpd_tls_security_level (empty)\fR" +# The SMTP TLS security level for the Postfix SMTP server; when +# a non-empty value is specified, this overrides the obsolete parameters +# smtpd_use_tls and smtpd_enforce_tls. +# .IP "\fBtls_random_source (see 'postconf -d' output)\fR" +# The external entropy source for the in-memory \fBtlsmgr\fR(8) pseudo +# random number generator (PRNG) pool. +# SEE ALSO +# master(8) Postfix master program +# postfix(1) Postfix administrative interface +# README FILES +# .ad +# .fi +# Use "\fBpostconf readme_directory\fR" or +# "\fBpostconf html_directory\fR" to locate this information. +# .na +# .nf +# TLS_README, Postfix TLS configuration and operation +# LICENSE +# .ad +# .fi +# The Secure Mailer license must be distributed with this software. +# HISTORY +# The "\fBpostfix tls\fR" command was introduced with Postfix +# version 3.1. +# AUTHOR(S) +# Viktor Dukhovni +#-- + +RSA_BITS=2048 # default +EC_CURVE=secp256r1 # default + +case $daemon_directory in +"") echo This script must be run by the postfix command. 1>&2 + echo Do not run directly. 1>&2 + exit 1;; +esac + +umask 022 +SHELL=/bin/sh + +postconf=$command_directory/postconf +LOGGER="$command_directory/postlog -t $MAIL_LOGTAG/postfix-tls-script" +INFO="$LOGGER -p info" +WARN="$LOGGER -p warn" +ERROR="$LOGGER -p error" +FATAL="$LOGGER -p fatal" + +# Overwrite SMTP client and server settings only when these are at defaults. +client_settings=" + smtp_use_tls + smtp_enforce_tls + smtp_tls_enforce_peername + smtp_tls_security_level + smtp_tls_cert_file + smtp_tls_dcert_file + smtp_tls_eccert_file +" + +server_settings=" + smtpd_use_tls + smtpd_enforce_tls + smtpd_tls_security_level + smtpd_tls_cert_file + smtpd_tls_dcert_file + smtpd_tls_eccert_file +" + +# +# Can't do much without these in place. +# +cd $command_directory || { + # Let's hope there's a "postlog" somewhere else on the PATH + FATAL="postlog -p fatal -t $MAIL_LOGTAG/postfix-tls-script" + msg="no Postfix command directory '${command_directory}'" + $FATAL "$msg" || { echo "$msg" >&2; sleep 1; } + exit 1 +} + +check_getopt() { + OPTIND=1 + a= + b= + c= + set -- -a 1 -b 2 -c -- -pos + while getopts :a:b:c o + do + case $o in + a) a="${OPTARG}";; + b) b="${OPTARG}";; + c) c=3;; + *) return 1;; + esac + done + shift `expr ${OPTIND} - 1` + if [ "${a}" != "1" -o "${b}" != 2 -o "${c}" != 3 \ + -o "${OPTIND}" -ne 7 -o "$1" != "-pos" ]; then + return 1 + fi +} + +check_getopt || { + $FATAL "/bin/sh does not implement a compatible 'getopts' built-in" + exit 1 +} + +# ----- BEGIN OpenSSL-specific ----- + +# No need to set the location of the OpenSSL command in each Postfix instance, +# the value from the default instance is used for all instances. +# +default_config_directory=`$postconf -dh config_directory` +openssl=`$postconf -c $default_config_directory -xh openssl_path` +"$openssl" version >/dev/null 2>&1 || { + $FATAL "No working openssl(1) command found with 'openssl_path = $openssl'" + exit 1 +} + +# ----- END OpenSSL-specific ----- + +test -n "$config_directory" -a -d "$config_directory" || { + $FATAL no Postfix configuration directory $config_directory! + exit 1 +} + +# Do we support TLS and if so which algorithms? +# +$postconf -T compile-version | grep . >/dev/null || { + mail_version=`$postconf -dh mail_version` + $FATAL "Postfix $mail_version is not compiled with TLS support" + exit 1 +} +rsa= +ecdsa= +for _algo in `$postconf -T public-key-algorithms | grep -E '^(rsa|ecdsa)$'` +do + eval $_algo=$_algo +done + +# ----- BEGIN OpenSSL-specific ----- + +if [ -n "${ecdsa}" ]; then + $openssl ecparam -name secp256r1 >/dev/null 2>&1 || { + cat <<-EOM | $WARN + Postfix supports ECDSA, but the $openssl command does not. Consider + setting the openssl_path parameter to a more capable version of the + command-line utility than $openssl (with PATH=$PATH). + EOM + ecdsa= + } +fi +if [ -n "${rsa}" ]; then + DEFALG=rsa +elif [ -n "${ecdsa}" ]; then + DEFALG=ecdsa +else + mail_version=`$postconf -dh mail_version` + $FATAL "Postfix $mail_version does not support either RSA or ECDSA" + exit 1 +fi + +# Make sure stdin is open when testing +if [ -r /dev/stdin ] < /dev/null; then + stdin=/dev/stdin +elif [ -r /dev/fd/0 ] </dev/null; then + stdin=/dev/fd/0 +else + $FATAL No /dev/fd/0 or /dev/stdin found + exit 1 +fi + +hex_sha256() { + $openssl dgst -binary -sha256 | od -An -vtx1 | tr -d ' \012' +} + +# We require SHA2-256 support from openssl(1) +# +null256=e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 +tmp=`hex_sha256 </dev/null 2>/dev/null` +if [ "${tmp}" != "${null256}" ]; then + cat <<EOF >&2 +Your $openssl does not support the SHA2-256 digest algorithm. To enable +'postfix tls', install an OpenSSL that does. Install its openssl(1) command +at /usr/local/bin/openssl or other suitable location, and set the +'openssl_path' parameter in $default_config_directory/main.cf accordingly. +EOF + $FATAL "No 'postfix tls' support when openssl(1) is obsolete" + exit 1 +fi + +read_key() { + [ -n "$1" -a -f "$1" ] || return 1 + + # Old OpenSSL versions return success even for unsupported sub-commands! + # So we inspect the output instead. Don't prompt if the key is password + # protected. + # + while read cmd key_algo key_param cert_param; do + $openssl $cmd -passin "pass:umask 077" -in "$1" | + grep . && return 0 + done 2>/dev/null <<-EOF + rsa rsa smtpd_tls_key_file smtpd_tls_cert_file + ec ecdsa smtpd_tls_eckey_file smtpd_tls_eccert_file + EOF + return 1 +} + +pubkey_dgst() { + [ -n "$1" -a -f "$1" ] || return 1 + + # Old OpenSSL versions return success even for unsupported sub-commands! + # So we inspect the output instead. + # + for cmd in ec rsa; do + $openssl $cmd -passin "pass:umask 077" -in "$1" -pubout | + $openssl $cmd -pubin -outform DER | + hex_sha256 | grep -E -v "${null256}" && return 0 + done 2>/dev/null + return 1 +} + +cert_pubkey_dgst() { + [ -n "$1" -a -f "$1" ] || return 1 + + # Old OpenSSL versions return success even for unsupported sub-commands! + # So we inspect the output instead. + # + for cmd in ec rsa; do + $openssl x509 -pubkey -noout -in "$1" | + $openssl $cmd -pubin -outform DER | + hex_sha256 | grep -E -v "${null256}" && return 0 + done 2>/dev/null + return 1 +} + +copy_key() { + _algo=$1; shift + _bits=$1; shift + _fold=$1; shift + _fnew=$1; shift + _umask=`umask` + + umask 077 + read_key "${_fold}" > "${_fnew}" # sets key_algo of current key + _ret=$? + umask "${_umask}" + + if [ "${_ret}" -ne 0 ]; then + $FATAL "Error copying private key from '${_fold}' to '${_fnew}'" + return 1 + fi + if [ "${key_algo}" != "${_algo}" ]; then + $FATAL "Key algorithm '$key_algo' of '${_fold}' is not '${_algo}'" + return 1 + fi + # XXX: We'd need C-code in postconf to portably check for compatible "bits" +} + +create_key() { + _algo=$1 + _bits=$2 + _fnew=$3 + _umask=`umask` + + case $_algo in + "") $FATAL "Internal error: empty algorithm"; return 1;; + $rsa) set -- "${openssl}" genrsa -out "${_fnew}" "${_bits}";; + $ecdsa) set -- "${openssl}" ecparam -param_enc named_curve -genkey \ + -out "${_fnew}" -name "${_bits}";; + *) $FATAL "Internal error: bad algorithm '${_algo}'" + return 1;; + esac + + umask 077 + _err=`"$@" 2>&1` + _ret=$? + umask "${_umask}" + + if [ "${_ret}" -ne 0 ]; then + echo "${_err}" | $WARN + $FATAL "error generating new ${_algo} ${_bits} private key" + return 1 + fi +} + +create_cert() { + _k=$1; shift + _c=$1; shift + set_fqdn "$1" + if [ $# -gt 0 ]; then shift; fi + set -- "$fqdn" "$@" + + if [ -r "${_c}" ]; then + $FATAL "New certificate file already exists: ${_c}" + return 1 + fi + + # Generate a new self-signed (~100 year) certificate + # + ( + echo "default_md = sha256" + echo "x509_extensions = v3" + echo "prompt = yes" + echo "distinguished_name = dn" + echo "[dn]" + echo "[v3]" + echo "basicConstraints = CA:false" + echo "subjectKeyIdentifier = hash" + echo "extendedKeyUsage = serverAuth, clientAuth" + echo "subjectAltName = @alts" + echo "[alts]" + i=1; for dns in "$@"; do + # XXX map empty to $myhostname + echo "DNS.$i = $dns" + i=`expr $i + 1` + done + ) | $openssl req -x509 -config $stdin -new -key "${_k}" \ + -subj "/CN=$fqdn" -days 36525 -out "${_c}" || { + rm -f "${_c}" "${_k}" + $FATAL "error generating self-signed SSL certificate" + return 1 + } +} + +output_server_csr() { + set_keyfile "$1" || return 1 + shift + set_fqdn "$1" || return 1 + shift + set -- "$fqdn" "$@" + ( + echo "default_md = sha256" + echo "req_extensions = v3" + echo "prompt = yes" + echo "distinguished_name = dn" + echo "[dn]" + echo "[v3]" + echo "subjectKeyIdentifier = hash" + echo "extendedKeyUsage = serverAuth, clientAuth" + echo "subjectAltName = @alts" + echo "[alts]" + i=1; for dns in "$@"; do + echo "DNS.$i = $dns" + i=`expr $i + 1` + done + ) | $openssl req -config $stdin -new -key "$keyfile" -subj / +} + +# ----- END OpenSSL-specific ----- + +info_enable_client() { + cat <<-EOM + *** Non-default SMTP client TLS settings detected, no changes made. + For opportunistic TLS in the Postfix SMTP client, the below settings + are typical: + smtp_tls_security_level = may + smtp_tls_loglevel = 1 + EOM + if get_cache_db_type dbtype + then + echo " smtp_tls_session_cache_database = ${dbtype}:\${data_directory}/smtp_scache" + fi +} + +info_client_deployed() { + cat <<-EOM + Enabled opportunistic TLS in the Postfix SMTP client. + Run the command: + # postfix reload + if you want the new settings to take effect immediately. + EOM +} + +info_enable_server() { + cat <<-EOM + *** Non-default SMTP server TLS settings detected, no changes made. + For opportunistic TLS in the Postfix SMTP server, the below settings + are typical: + smtpd_tls_security_level = may + smtpd_tls_loglevel = 1 + You can use "postfix tls new-server-cert" to create a new certificate. + Or, "postfix tls new-server-key" to also force a new private key. + If you publish DANE TLSA records, see: + https://tools.ietf.org/html/rfc7671#section-8 + https://tools.ietf.org/html/rfc7671#section-5.1 + https://tools.ietf.org/html/rfc7671#section-5.2 + https://community.letsencrypt.org/t/please-avoid-3-0-1-and-3-0-2-dane-tlsa-records-with-le-certificates/7022 + EOM +} + +# args: certfile keyfile deploy +info_created() { + cat <<-EOM + New private key and self-signed certificate created. To deploy run: + # postfix tls deploy-server-cert $1 $2 + EOM +} + +# args: certfile keyfile deploy +info_server_deployed() { + if [ "$3" = "enable" ]; then + echo "Enabled opportunistic TLS in the Postfix SMTP server" + fi + cat <<-EOM + New TLS private key and certificate deployed. + Run the command: + # postfix reload + if you want the new settings to take effect immediately. + EOM +} + +# args: certfile keyfile deploy +info_csr() { + cat <<-EOM + To generate a CSR run: + # postfix tls output-server-csr -k $2 [<hostname> ...] + EOM + if [ -z "$3" ]; then + echo "Save the signed certificate chain in $1, and deploy as above." + else + echo "Save the signed certificate chain in $1." + fi +} + +# args: certfile keyfile deploy +info_tlsa() { + # If already deployed, info for how to show all the deployed keys. + # Otherwise, just the new keys, so that TLSA records can be updated + # first. + if [ -n "$3" ]; then shift $#; fi + cat <<-EOM + To generate TLSA records run: + # postfix tls output-server-tlsa [-h <hostname>] $2 + EOM +} + +# args: certfile keyfile deploy +info_dane_dns() { + # If already deployed, too late to wait, otherwise advise updating TLSA + # RRs before deployment. + if [ -n "$3" ]; then + cat <<-EOM + (If you have DANE TLSA RRs, update them as soon as possible to match + the newly deployed keys). + EOM + else + cat <<-EOM + (deploy after updating the DNS and waiting for stale RRs to expire). + EOM + fi +} + +set_fqdn() { + if [ -n "$1" ]; then fqdn=$1; return 0; fi + fqdn=`$postconf -xh myhostname` || return 1 + case $fqdn in /*) fqdn=`cat "${fqdn}"` || return 1;; esac +} + +set_keyfile() { + keyfile=$1 + case $keyfile in + rsa) if [ -n "${rsa}" ]; then + keyfile=`$postconf -nxh smtpd_tls_key_file` + else + keyfile= + fi + ;; + ecdsa) if [ -n "${ecdsa}" ]; then + keyfile=`$postconf -nxh smtpd_tls_eckey_file` + else + keyfile= + fi + ;; + "") : empty ok;; + none) : see below;; + /*) ;; + *) # User-specified key pathnames are relative to the configuration + # directory + keyfile="${config_directory}/${keyfile}";; + esac + if [ "${keyfile}" = "none" ]; then keyfile= ; fi +} + +check_key() { + read_key "$1" >/dev/null && return 0 + $FATAL "no private key found in file: $1" + return 1 +} + +# Create new key or copy existing if specified. +# +ensure_key() { + _algo=$1; shift + _bits=$1; shift + stamp=`TZ=UTC date +%Y%m%d-%H%M%S` + + case $_algo in + "") $FATAL "Internal error: empty algorithm "; return 1;; + $rsa) keyfile="${config_directory}/key-${stamp}.pem" + certfile="${config_directory}/cert-${stamp}.pem";; + $ecdsa) keyfile="${config_directory}/eckey-${stamp}.pem" + certfile="${config_directory}/eccert-${stamp}.pem";; + *) $FATAL "Internal error: bad algorithm '${_algo}'" + return 1;; + esac + + if [ -r "${keyfile}" ]; then + $FATAL "New private key file already exists: ${keyfile}" + return 1 + fi + if [ -r "${certfile}" ]; then + $FATAL "New certificate file already exists: ${certfile}" + return 1 + fi + + if [ -n "$1" ]; then + copy_key "${_algo}" "${_bits}" "$1" "${keyfile}" && return 0 + else + create_key "${_algo}" "${_bits}" "${keyfile}" && return 0 + fi + rm -f "${keyfile}" + return 1 +} + +init_random_source() { + tls_random_source=$1 + + if [ -z "${tls_random_source}" ]; then + tls_random_source=`$postconf -xh tls_random_source` + fi + if [ -n "${tls_random_source}" ]; then + return 0 + fi + if [ -r /dev/urandom ] + then + tls_random_source=dev:/dev/urandom + else + $FATAL no default TLS random source defined and no /dev/urandom + return 1 + fi +} + +# Don't be too clever by half. +all_default() { + for var in "$@" + do + val=`$postconf -nh "${var}"` + if [ -n "$val" ]; then return 1; fi + done + return 0 +} + +# Select read-write database type for TLS session caches. +# +get_cache_db_type() { + var=$1; shift + prio=0 + ret=1 + for _dbtype in `$postconf -m` + do + _prio=0 + case $_dbtype in + lmdb) _prio=2;; + btree) _prio=1;; + esac + if [ "$_prio" -gt "$prio" ] + then + eval "$var=\$_dbtype" + prio=$_prio + ret=0 + fi + done + return $ret +} + +deploy_server_cert() { + certfile=$1; shift + keyfile=$1; shift + case $# in 0) deploy=;; *) deploy=$1; shift;; esac + + # Sets key_algo, key_param and cert_param + check_key "$keyfile" || return 1 + + cd=`cert_pubkey_dgst "${certfile}"` || { + $FATAL "error computing certificate public key digest" + return 1 + } + kd=`pubkey_dgst "$keyfile"` || { + $FATAL "error computing public key digest" + return 1 + } + + if [ "$cd" != "$kd" ]; then + $FATAL "Certificate in ${certfile} does not match key in ${keyfile}" + return 1 + fi + + set -- \ + "${key_param} = ${keyfile}" \ + "${cert_param} = ${certfile}" + + if [ "${deploy}" = "enable" ]; then + set -- "$@" \ + "smtpd_tls_security_level = may" \ + "smtpd_tls_received_header = yes" \ + "smtpd_tls_loglevel = 1" + fi + + if [ -n "${tls_random_source}" ]; then + set -- "$@" "tls_random_source = ${tls_random_source}" + fi + + # All in one shot, since postconf delays modifying "hot" main.cf files. + $postconf -e "$@" || return 1 +} + +# Prepare a new cert and perhaps re-use any existing private key. +# +new_server_cert() { + algo=$1; shift + bits=$1; shift + oldkey=$1; shift + deploy=$1; shift + + # resets keyfile (copy or else new) and new certfile + ensure_key "$algo" "$bits" "${oldkey}" || return 1 + create_cert "${keyfile}" "${certfile}" "$@" || return 1 + if [ -n "${deploy}" ]; then + deploy_server_cert "${certfile}" "${keyfile}" "${deploy}" || return 1 + fi + + ( + if [ -z "${deploy}" ]; then + info_created "${certfile}" "${keyfile}" "${deploy}" + else + info_server_deployed "${certfile}" "${keyfile}" "${deploy}" + fi + info_csr "${certfile}" "${keyfile}" "${deploy}" + info_tlsa "${certfile}" "${keyfile}" "${deploy}" + if [ -z "${oldkey}" ]; then + info_dane_dns "${certfile}" "${keyfile}" "${deploy}" + fi + ) | $INFO +} + +enable_client() { + if all_default ${client_settings} + then + set -- \ + "smtp_tls_security_level = may" \ + "smtp_tls_loglevel = 1" + + if get_cache_db_type dbtype + then + set -- "$@" \ + "smtp_tls_session_cache_database = ${dbtype}:${data_directory}/smtp_scache" + fi + + if [ -n "${tls_random_source}" ]; then + set -- "$@" "tls_random_source = ${tls_random_source}" + fi + + # All in one shot, since postconf delays modifying "hot" main.cf files. + $postconf -e "$@" || return 1 + info_client_deployed + else + info_enable_client + fi | $INFO +} + +enable_server() { + algo=$1; shift + bits=$1; shift + + if all_default ${server_settings} + then + # algo bits keyfile deploy [hostnames ...] + new_server_cert "${algo}" "${bits}" "" "enable" "$@" || return 1 + else + info_enable_server | $INFO + fi +} + +output_server_tlsa() { + hostname=$1 + check_key "$2" || return 1 + data=`pubkey_dgst "$2"` || return 1 + if [ -z "$data" ] + then + $FATAL error computing SHA2-256 SPKI digest of "$key" + return 1 + fi + echo "_25._tcp.$hostname. IN TLSA 3 1 1 $data" +} + +# +# Parse JCL +# +case $1 in +enable-client) + cmd=$1; shift; OPTIND=1 + rand= + while getopts :r: _opt + do + case $_opt in + r) rand="${OPTARG}";; + *) $FATAL "usage: postfix tls $cmd [-r devrandom]" + exit 1;; + esac + done + + # No positional arguments supported with enable-client + if [ $# -ge "${OPTIND}" ]; then + $FATAL "usage: postfix tls $cmd [-r devrandom]" + exit 1 + fi + # But, shift anyway + shift `expr $OPTIND - 1` + + init_random_source "${rand}" || exit 1 + enable_client || exit 1 + ;; + +enable-server) + cmd=$1; shift; OPTIND=1 + algo=$DEFALG + bits= + rand= + while getopts :a:b:r: _opt + do + case $_opt in + a) algo="${OPTARG}";; + b) bits="${OPTARG}";; + r) rand="${OPTARG}";; + *) $FATAL "usage: postfix tls $cmd [-a algorithm] [-b bits ] [-r devrandom] [hostname ...]" + exit 1;; + esac + done + + # Here positional arguments are hostnames for the new certificate, as + # many as the user wants + shift `expr $OPTIND - 1` + + case $algo in + "") $FATAL "Internal error: empty algorithm "; return 1;; + $rsa) : ${bits:=${RSA_BITS}};; + $ecdsa) : ${bits:=${EC_CURVE}};; + *) $FATAL "Unsupported private key algorithm: $algo" + exit 1;; + esac + + init_random_source "${rand}" || exit 1 + enable_server "${algo}" "${bits}" "$@" || exit 1 + ;; + +new-server-key) + cmd=$1; shift; OPTIND=1 + algo=$DEFALG + while getopts :a:b: _opt + do + case $_opt in + a) algo="${OPTARG}";; + b) bits="${OPTARG}";; + *) $FATAL "usage: postfix tls $cmd [-a algorithm] [-b bits ] [hostname ...]" + exit 1;; + esac + done + + # Here positional arguments are hostnames for the new certificate, as + # many as the user wants + shift `expr $OPTIND - 1` + + case $algo in + "") $FATAL "Internal error: empty algorithm "; return 1;; + $rsa) : ${bits:=${RSA_BITS}};; + $ecdsa) : ${bits:=${EC_CURVE}};; + *) $FATAL "Unsupported public key algorithm: $algo" + exit 1;; + esac + + # Force new key + new_server_cert "${algo}" "${bits}" "" "" "$@" || exit 1 + ;; + +new-server-cert) + cmd=$1; shift; OPTIND=1 + algo=$DEFALG + while getopts :a:b: _opt + do + case $_opt in + a) algo="${OPTARG}";; + b) bits="${OPTARG}";; + *) $FATAL "usage: postfix tls $cmd [-a algorithm] [-b bits ] [hostname ...]" + exit 1;; + esac + done + + # Here positional arguments are hostnames for the new certificate, as + # many as the user wants + shift `expr $OPTIND - 1` + + case $algo in + "") $FATAL "Invalid empty key algorithm"; exit 1;; + $rsa) : ${bits:=${RSA_BITS}};; + $ecdsa) : ${bits:=${EC_CURVE}};; + *) $FATAL "Unsupported private key algorithm: $algo" + exit 1;; + esac + + # Existing keyfile or empty + set_keyfile "${algo}" + + if [ -n "${keyfile}" -a ! -f "${keyfile}" ]; then + echo "Key file: ${keyfile} not found, creating new keys" | $WARN + keyfile= + fi + + # Try to re-use (copy) existing key. + new_server_cert "${algo}" "${bits}" "${keyfile}" "" "$@" || exit 1 + ;; + +deploy-server-cert) + if [ $# -ne 3 ]; then + $FATAL "usage: postfix tls $1 certfile keyfile" + exit 1 + fi + shift + + # User-specified key and cert pathnames are relative to the + # configuration directory + # + case "${1}" in + /*) certfile="${1}" ;; + *) certfile="${config_directory}/${1}" ;; + esac + case "${2}" in + /*) keyfile="${2}" ;; + *) keyfile="${config_directory}/${2}" ;; + esac + + deploy_server_cert "${certfile}" "${keyfile}" || exit 1 + info_server_deployed "${certfile}" "${keyfile}" "deploy" | $INFO + ;; + +output-server-csr) + cmd=$1; shift; OPTIND=1 + k= + while getopts :k: _opt + do + case $_opt in + k) k="${OPTARG}";; + *) $FATAL "usage: postfix tls $cmd [-k keyfile] [hostname ...]" + exit 1;; + esac + done + + # Here positional arguments are hostnames for the new certificate, as + # many as the user wants + shift `expr $OPTIND - 1` + + if [ -n "${k}" ]; then + set_keyfile "${k}" + else + for _algo in $rsa $ecdsa + do + set_keyfile "${_algo}" + if [ -n "${keyfile}" ]; then + break + fi + done + fi + + if [ -z "${keyfile}" -o ! -r "${keyfile}" ]; then + $FATAL "No usable keyfile specified or configured" + exit 1 + fi + + # Default <hostname> from $myhostname + if [ $# -eq 0 ]; then + set_fqdn + set -- "$fqdn" + fi + + # Output a CSR for the requested names + output_server_csr "$keyfile" "$@" || exit 1 + ;; + +output-server-tlsa) + cmd=$1; shift; OPTIND=1 + hostname= + while getopts :h: _opt + do + case $_opt in + h) hostname="${OPTARG}";; + *) $FATAL "usage: postfix tls $cmd [-h hostname] [keyfile ...]" + exit 1;; + esac + done + set_fqdn "${hostname}" + + # Here positional arguments are keyfiles for which we output "3 1 1" + # TLSA RRs, as many keyfiles as the user wants. By default the live + # RSA and/or ECDSA keys. + shift `expr $OPTIND - 1` + + if [ $# -eq 0 ]; then set -- $rsa $ecdsa; fi + + found= + for _k in "$@" + do + set_keyfile "${_k}" + if [ -z "${keyfile}" ]; then continue; fi + echo "; ${keyfile}" + output_server_tlsa "${fqdn}" "${keyfile}" || exit 1 + found=1 + done + if [ -z "${found}" ]; then + $FATAL "No usable keyfiles specified or configured" + exit 1 + fi + ;; + +all-default-client) + cmd=$1; shift; OPTIND=1 + + # No arguments for all-default-client + if [ $# -ge "${OPTIND}" ]; then + $FATAL "usage: postfix tls $cmd" + exit 1 + fi + + all_default ${client_settings} || exit 1 + ;; + +all-default-server) + cmd=$1; shift; OPTIND=1 + + # No arguments for all-default-server + if [ $# -ge "${OPTIND}" ]; then + $FATAL "usage: postfix tls $cmd" + exit 1 + fi + + all_default ${server_settings} || exit 1 + ;; + +*) + $ERROR "unknown tls command: '$1'" + $FATAL "usage: postfix tls enable-client (or enable-server, new-server-key, new-server-cert, deploy-server-cert, output-server-csr, output-server-tlsa, all-default-client, all-default-server)" + exit 1 + ;; + +esac |