On Wed, Dec 23, 2015 at 06:01:33PM +0000, Jeremy Harris wrote:
> Then it's all DNS configuration - and there are several options.
> If you want EE cert-usage (end-entity, meaning "the leaf
> cert should match this") then records like this:
>
>
> dane256ee A HOSTIPV4
> _25._tcp.dane256ee TLSA 3 1 1
> 2bb55f418bb03411a5007cecbfcd3ec1c94404312c0d53a44bb2166b32654db3
For things NOT to do, see:
https://dane.sys4.de/common_mistakes
https://community.letsencrypt.org/t/please-avoid-3-0-1-and-3-0-2-dane-tlsa-records-with-le-certificates/7022
I'm attaching two scripts that make it easier to generate TLSA records
for a leaf certificate, or a complete chain, respectively.
> Duplicate TLSAs for any other ports needed apart from 25.
> Other variants are possible; see rfc 6698 section 2 for
> details - but pretty much only EE & TA cert-usage are
> useful for SMTP.
Only DANE-EE and DANE-TA are useful for SMTP, the PKIX-EE and
PKIX-TA usages are undefined for SMTP and should be avoided.
https://tools.ietf.org/html/rfc7672#section-3.1
https://tools.ietf.org/html/rfc7671#section-5
--
Viktor.
#! /usr/bin/env bash
# Bash needed for PIPESTATUS array
extract() {
case "$4" in
0) openssl x509 -in "$1" -outform DER;;
1) openssl x509 -in "$1" -noout -pubkey | openssl pkey -pubin -outform DER;;
esac
}
digest() {
case "$5" in
0) cat;;
1) openssl dgst -sha256 -binary;;
2) openssl dgst -sha512 -binary;;
esac
}
encode() {
local cert=$1; shift
local hostport=$1; shift
local u=$1; shift
local s=$1; shift
local m=$1; shift
local host=$hostport
local port=25
OIFS="$IFS"; IFS=":"; set -- $hostport; IFS="$OIFS"
if [ $# -eq 2 ]; then host=$1; port=$2; fi
printf "_%d._tcp.%s. IN TLSA %d %d %d %s\n" \
"$port" "$host" "$u" "$s" "$m" \
"$(hexdump -ve '/1 "%02X"')"
}
error() { echo "$1" 1>&2; exit 1; }
usage() { error "Usage: $0 cert.pem host[:port] usage selector mtype"; }
if [ $# -ne 5 ]; then usage; fi
case "$(echo $3 | tr '[A-Z]' '[a-z]')" in
0|pkix-[ct]a) usage=0;;
1|pkix-ee) usage=1;;
2|dane-[ct]a) usage=2;;
3|dane-ee) usage=3;;
*) error "Invalid certificate usage: $3";;
esac
case "$(echo $4 | tr '[A-Z]' '[a-z]')" in
0|cert) selector=0;;
1|spki|pkey) selector=1;;
*) error "Invalid selector: $4";;
esac
case "$(echo $5 | tr '[A-Z]' '[a-z]')" in
0|full) mtype=0;;
1|sha2-256|sha256|sha-256) mtype=1;;
2|sha2-512|sha512|sha-512) mtype=2;;
*) error "Invalid matching type: $5";;
esac
set -- "$1" "$2" "$usage" "$selector" "$mtype"
rr=$(
extract "$@" | digest "$@" | encode "$@"
exit $(( ${PIPESTATUS[0]} | ${PIPESTATUS[1]} | ${PIPESTATUS[2]} ))
)
status=$?
if [ $status -ne 0 ]; then
exit $status
fi
echo "$rr"
#! /usr/bin/env bash
# Bash needed for PIPESTATUS array
extract() {
case "$4" in
0) openssl x509 -in "$1" -outform DER;;
1) openssl x509 -in "$1" -noout -pubkey | openssl pkey -pubin -outform DER;;
esac
}
digest() {
case "$5" in
0) cat;;
1) openssl dgst -sha256 -binary;;
2) openssl dgst -sha512 -binary;;
esac
}
encode() {
local cert=$1; shift
local hostport=$1; shift
local u=$1; shift
local s=$1; shift
local m=$1; shift
local host=$hostport
local port=25
OIFS="$IFS"; IFS=":"; set -- $hostport; IFS="$OIFS"
if [ $# -eq 2 ]; then host=$1; port=$2; fi
printf "_%d._tcp.%s. IN TLSA %d %d %d %s\n" \
"$port" "$host" "$u" "$s" "$m" \
"$(hexdump -ve '/1 "%02X"')"
}
genrr() {
rr=$(
extract "$@" | digest "$@" | encode "$@"
exit $(( ${PIPESTATUS[0]} | ${PIPESTATUS[1]} | ${PIPESTATUS[2]} ))
)
status=$?; if [ $status -ne 0 ]; then exit $status; fi
echo "$rr"
}
error() { echo "$1" 1>&2; exit 1; }
usage() { error "Usage: $0 chain.pem host[:port]"; }
if [ $# -ne 2 ]; then usage; fi
# Validate and normalize the chain
#
certfile=$1; shift
chain="$(
openssl crl2pkcs7 -nocrl -certfile "$certfile" |
openssl pkcs7 -print_certs
exit $(( ${PIPESTATUS[0]} | ${PIPESTATUS[1]} ))
)"
status=$?; if [ $status -ne 0 ]; then exit $status; fi
hostport=$1; shift
usage=3
cert=
printf "%s\n\n" "$chain" |
while read line
do
if [[ -z "$cert" && ! "$line" =~ ^-----BEGIN ]]; then
continue
fi
cert=$(printf "%s\n%s" "$cert" "$line")
if [ -z "$line" -a ! -z "$cert" ]; then
echo "$cert" |
openssl x509 -noout -subject -issuer -dates |
sed -e 's/^/;; /'
echo ";;"
genrr <(echo "$cert") "$hostport" $usage 0 1
genrr <(echo "$cert") "$hostport" $usage 1 1
genrr <(echo "$cert") "$hostport" $usage 0 2
genrr <(echo "$cert") "$hostport" $usage 1 2
echo
cert=""
usage=2
fi
done
--
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