# $OpenBSD: cert-hostkey.sh,v 1.21 2019/12/11 18:47:14 djm Exp $ # Placed in the Public Domain. tid="certified host keys" rm -f $OBJ/known_hosts-cert* $OBJ/host_ca_key* $OBJ/host_revoked_* rm -f $OBJ/cert_host_key* $OBJ/host_krl_* # Allow all hostkey/pubkey types, prefer certs for the client rsa=0 types="" for i in `$SSH -Q key | filter_sk`; do if [ -z "$types" ]; then types="$i" continue fi case "$i" in # Special treatment for RSA keys. *rsa*cert*) types="rsa-sha2-256-cert-v01@openssh.com,$i,$types" types="rsa-sha2-512-cert-v01@openssh.com,$types";; *rsa*) rsa=1 types="$types,rsa-sha2-512,rsa-sha2-256,$i";; # Prefer certificate to plain keys. *cert*) types="$i,$types";; *) types="$types,$i";; esac done ( echo "HostKeyAlgorithms ${types}" echo "PubkeyAcceptedKeyTypes *" ) >> $OBJ/ssh_proxy cp $OBJ/sshd_proxy $OBJ/sshd_proxy_bak ( echo "HostKeyAlgorithms *" echo "PubkeyAcceptedKeyTypes *" ) >> $OBJ/sshd_proxy_bak HOSTS='localhost-with-alias,127.0.0.1,::1' kh_ca() { for k in "$@" ; do printf "@cert-authority $HOSTS " cat $OBJ/$k || fatal "couldn't cat $k" done } kh_revoke() { for k in "$@" ; do printf "@revoked * " cat $OBJ/$k || fatal "couldn't cat $k" done } # Create a CA key and add it to known hosts. Ed25519 chosen for speed. # RSA for testing RSA/SHA2 signatures if supported. ktype2=ed25519 [ "x$rsa" = "x1" ] && ktype2=rsa ${SSHKEYGEN} -q -N '' -t ed25519 -f $OBJ/host_ca_key ||\ fail "ssh-keygen of host_ca_key failed" ${SSHKEYGEN} -q -N '' -t $ktype2 -f $OBJ/host_ca_key2 ||\ fail "ssh-keygen of host_ca_key failed" kh_ca host_ca_key.pub host_ca_key2.pub > $OBJ/known_hosts-cert.orig cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert # Plain text revocation files touch $OBJ/host_revoked_empty touch $OBJ/host_revoked_plain touch $OBJ/host_revoked_cert cat $OBJ/host_ca_key.pub $OBJ/host_ca_key2.pub > $OBJ/host_revoked_ca PLAIN_TYPES=`$SSH -Q key-plain | filter_sk | sed 's/^ssh-dss/ssh-dsa/g;s/^ssh-//'` if echo "$PLAIN_TYPES" | grep '^rsa$' >/dev/null 2>&1 ; then PLAIN_TYPES="$PLAIN_TYPES rsa-sha2-256 rsa-sha2-512" fi # Prepare certificate, plain key and CA KRLs ${SSHKEYGEN} -kf $OBJ/host_krl_empty || fatal "KRL init failed" ${SSHKEYGEN} -kf $OBJ/host_krl_plain || fatal "KRL init failed" ${SSHKEYGEN} -kf $OBJ/host_krl_cert || fatal "KRL init failed" ${SSHKEYGEN} -kf $OBJ/host_krl_ca $OBJ/host_ca_key.pub $OBJ/host_ca_key2.pub \ || fatal "KRL init failed" # Generate and sign host keys serial=1 for ktype in $PLAIN_TYPES ; do verbose "$tid: sign host ${ktype} cert" # Generate and sign a host key ${SSHKEYGEN} -q -N '' -t ${ktype} \ -f $OBJ/cert_host_key_${ktype} || \ fatal "ssh-keygen of cert_host_key_${ktype} failed" ${SSHKEYGEN} -ukf $OBJ/host_krl_plain \ $OBJ/cert_host_key_${ktype}.pub || fatal "KRL update failed" cat $OBJ/cert_host_key_${ktype}.pub >> $OBJ/host_revoked_plain case $ktype in rsa-sha2-*) tflag="-t $ktype"; ca="$OBJ/host_ca_key2" ;; *) tflag=""; ca="$OBJ/host_ca_key" ;; esac ${SSHKEYGEN} -h -q -s $ca -z $serial $tflag \ -I "regress host key for $USER" \ -n $HOSTS $OBJ/cert_host_key_${ktype} || fatal "couldn't sign cert_host_key_${ktype}" ${SSHKEYGEN} -ukf $OBJ/host_krl_cert \ $OBJ/cert_host_key_${ktype}-cert.pub || \ fatal "KRL update failed" cat $OBJ/cert_host_key_${ktype}-cert.pub >> $OBJ/host_revoked_cert serial=`expr $serial + 1` done attempt_connect() { _ident="$1" _expect_success="$2" shift; shift verbose "$tid: $_ident expect success $_expect_success" cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert ${SSH} -oUserKnownHostsFile=$OBJ/known_hosts-cert \ -oGlobalKnownHostsFile=$OBJ/known_hosts-cert \ "$@" -F $OBJ/ssh_proxy somehost true _r=$? if [ "x$_expect_success" = "xyes" ] ; then if [ $_r -ne 0 ]; then fail "ssh cert connect $_ident failed" fi else if [ $_r -eq 0 ]; then fail "ssh cert connect $_ident succeeded unexpectedly" fi fi } # Basic connect and revocation tests. for privsep in yes ; do for ktype in $PLAIN_TYPES ; do verbose "$tid: host ${ktype} cert connect privsep $privsep" ( cat $OBJ/sshd_proxy_bak echo HostKey $OBJ/cert_host_key_${ktype} echo HostCertificate $OBJ/cert_host_key_${ktype}-cert.pub echo UsePrivilegeSeparation $privsep ) > $OBJ/sshd_proxy # test name expect success attempt_connect "$ktype basic connect" "yes" attempt_connect "$ktype empty KRL" "yes" \ -oRevokedHostKeys=$OBJ/host_krl_empty attempt_connect "$ktype KRL w/ plain key revoked" "no" \ -oRevokedHostKeys=$OBJ/host_krl_plain attempt_connect "$ktype KRL w/ cert revoked" "no" \ -oRevokedHostKeys=$OBJ/host_krl_cert attempt_connect "$ktype KRL w/ CA revoked" "no" \ -oRevokedHostKeys=$OBJ/host_krl_ca attempt_connect "$ktype empty plaintext revocation" "yes" \ -oRevokedHostKeys=$OBJ/host_revoked_empty attempt_connect "$ktype plain key plaintext revocation" "no" \ -oRevokedHostKeys=$OBJ/host_revoked_plain attempt_connect "$ktype cert plaintext revocation" "no" \ -oRevokedHostKeys=$OBJ/host_revoked_cert attempt_connect "$ktype CA plaintext revocation" "no" \ -oRevokedHostKeys=$OBJ/host_revoked_ca done done # Revoked certificates with key present kh_ca host_ca_key.pub host_ca_key2.pub > $OBJ/known_hosts-cert.orig for ktype in $PLAIN_TYPES ; do test -f "$OBJ/cert_host_key_${ktype}.pub" || fatal "no pubkey" kh_revoke cert_host_key_${ktype}.pub >> $OBJ/known_hosts-cert.orig done cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert for privsep in yes ; do for ktype in $PLAIN_TYPES ; do verbose "$tid: host ${ktype} revoked cert privsep $privsep" ( cat $OBJ/sshd_proxy_bak echo HostKey $OBJ/cert_host_key_${ktype} echo HostCertificate $OBJ/cert_host_key_${ktype}-cert.pub echo UsePrivilegeSeparation $privsep ) > $OBJ/sshd_proxy cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert ${SSH} -oUserKnownHostsFile=$OBJ/known_hosts-cert \ -oGlobalKnownHostsFile=$OBJ/known_hosts-cert \ -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1 if [ $? -eq 0 ]; then fail "ssh cert connect succeeded unexpectedly" fi done done # Revoked CA kh_ca host_ca_key.pub host_ca_key2.pub > $OBJ/known_hosts-cert.orig kh_revoke host_ca_key.pub host_ca_key2.pub >> $OBJ/known_hosts-cert.orig cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert for ktype in $PLAIN_TYPES ; do verbose "$tid: host ${ktype} revoked cert" ( cat $OBJ/sshd_proxy_bak echo HostKey $OBJ/cert_host_key_${ktype} echo HostCertificate $OBJ/cert_host_key_${ktype}-cert.pub ) > $OBJ/sshd_proxy cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert ${SSH} -oUserKnownHostsFile=$OBJ/known_hosts-cert \ -oGlobalKnownHostsFile=$OBJ/known_hosts-cert \ -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1 if [ $? -eq 0 ]; then fail "ssh cert connect succeeded unexpectedly" fi done # Create a CA key and add it to known hosts kh_ca host_ca_key.pub host_ca_key2.pub > $OBJ/known_hosts-cert.orig cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert test_one() { ident=$1 result=$2 sign_opts=$3 for kt in $PLAIN_TYPES; do case $ktype in rsa-sha2-*) tflag="-t $ktype"; ca="$OBJ/host_ca_key2" ;; *) tflag=""; ca="$OBJ/host_ca_key" ;; esac ${SSHKEYGEN} -q -s $ca $tflag -I "regress host key for $USER" \ $sign_opts $OBJ/cert_host_key_${kt} || fatal "couldn't sign cert_host_key_${kt}" ( cat $OBJ/sshd_proxy_bak echo HostKey $OBJ/cert_host_key_${kt} echo HostCertificate $OBJ/cert_host_key_${kt}-cert.pub ) > $OBJ/sshd_proxy cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert ${SSH} -oUserKnownHostsFile=$OBJ/known_hosts-cert \ -oGlobalKnownHostsFile=$OBJ/known_hosts-cert \ -F $OBJ/ssh_proxy somehost true >/dev/null 2>&1 rc=$? if [ "x$result" = "xsuccess" ] ; then if [ $rc -ne 0 ]; then fail "ssh cert connect $ident failed unexpectedly" fi else if [ $rc -eq 0 ]; then fail "ssh cert connect $ident succeeded unexpectedly" fi fi done } test_one "user-certificate" failure "-n $HOSTS" test_one "empty principals" success "-h" test_one "wrong principals" failure "-h -n foo" test_one "cert not yet valid" failure "-h -V20200101:20300101" test_one "cert expired" failure "-h -V19800101:19900101" test_one "cert valid interval" success "-h -V-1w:+2w" test_one "cert has constraints" failure "-h -Oforce-command=false" # Check downgrade of cert to raw key when no CA found for ktype in $PLAIN_TYPES ; do rm -f $OBJ/known_hosts-cert $OBJ/cert_host_key* verbose "$tid: host ${ktype} ${v} cert downgrade to raw key" # Generate and sign a host key ${SSHKEYGEN} -q -N '' -t ${ktype} -f $OBJ/cert_host_key_${ktype} || \ fail "ssh-keygen of cert_host_key_${ktype} failed" case $ktype in rsa-sha2-*) tflag="-t $ktype"; ca="$OBJ/host_ca_key2" ;; *) tflag=""; ca="$OBJ/host_ca_key" ;; esac ${SSHKEYGEN} -h -q $tflag -s $ca $tflag \ -I "regress host key for $USER" \ -n $HOSTS $OBJ/cert_host_key_${ktype} || fatal "couldn't sign cert_host_key_${ktype}" ( printf "$HOSTS " cat $OBJ/cert_host_key_${ktype}.pub ) > $OBJ/known_hosts-cert ( cat $OBJ/sshd_proxy_bak echo HostKey $OBJ/cert_host_key_${ktype} echo HostCertificate $OBJ/cert_host_key_${ktype}-cert.pub ) > $OBJ/sshd_proxy ${SSH} -oUserKnownHostsFile=$OBJ/known_hosts-cert \ -oGlobalKnownHostsFile=$OBJ/known_hosts-cert \ -F $OBJ/ssh_proxy somehost true if [ $? -ne 0 ]; then fail "ssh cert connect failed" fi done # Wrong certificate kh_ca host_ca_key.pub host_ca_key2.pub > $OBJ/known_hosts-cert.orig cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert for kt in $PLAIN_TYPES ; do verbose "$tid: host ${kt} connect wrong cert" rm -f $OBJ/cert_host_key* # Self-sign key ${SSHKEYGEN} -q -N '' -t ${kt} -f $OBJ/cert_host_key_${kt} || \ fail "ssh-keygen of cert_host_key_${kt} failed" case $kt in rsa-sha2-*) tflag="-t $kt" ;; *) tflag="" ;; esac ${SSHKEYGEN} $tflag -h -q -s $OBJ/cert_host_key_${kt} \ -I "regress host key for $USER" \ -n $HOSTS $OBJ/cert_host_key_${kt} || fatal "couldn't sign cert_host_key_${kt}" ( cat $OBJ/sshd_proxy_bak echo HostKey $OBJ/cert_host_key_${kt} echo HostCertificate $OBJ/cert_host_key_${kt}-cert.pub ) > $OBJ/sshd_proxy cp $OBJ/known_hosts-cert.orig $OBJ/known_hosts-cert ${SSH} -oUserKnownHostsFile=$OBJ/known_hosts-cert \ -oGlobalKnownHostsFile=$OBJ/known_hosts-cert \ -F $OBJ/ssh_proxy -q somehost true >/dev/null 2>&1 if [ $? -eq 0 ]; then fail "ssh cert connect $ident succeeded unexpectedly" fi done rm -f $OBJ/known_hosts-cert* $OBJ/host_ca_key* $OBJ/cert_host_key*