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Diffstat (limited to 'regress/limit-keytype.sh')
| -rw-r--r-- | regress/limit-keytype.sh | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/regress/limit-keytype.sh b/regress/limit-keytype.sh new file mode 100644 index 0000000..7127de0 --- /dev/null +++ b/regress/limit-keytype.sh @@ -0,0 +1,133 @@ +# $OpenBSD: limit-keytype.sh,v 1.10 2021/02/25 03:27:34 djm Exp $ +# Placed in the Public Domain. + +tid="restrict pubkey type" + +# XXX sk-* keys aren't actually tested ATM. + +rm -f $OBJ/authorized_keys_$USER $OBJ/user_ca_key* $OBJ/user_key* +rm -f $OBJ/authorized_principals_$USER $OBJ/cert_user_key* + +mv $OBJ/sshd_proxy $OBJ/sshd_proxy.orig +mv $OBJ/ssh_proxy $OBJ/ssh_proxy.orig + +ktype1=ed25519; ktype2=ed25519; ktype3=ed25519; +ktype4=ed25519; ktype5=ed25519; ktype6=ed25519; +for t in $SSH_KEYTYPES ; do + case "$t" in + ssh-rsa) ktype2=rsa ;; + ecdsa*) ktype3=ecdsa ;; # unused + ssh-dss) ktype4=dsa ;; + sk-ssh-ed25519@openssh.com) ktype5=ed25519-sk ;; + sk-ecdsa-sha2-nistp256@openssh.com) ktype6=ecdsa-sk ;; + esac +done + +# Create a CA key +${SSHKEYGEN} -q -N '' -t $ktype1 -f $OBJ/user_ca_key ||\ + fatal "ssh-keygen failed" + +# Make some keys and a certificate. +${SSHKEYGEN} -q -N '' -t $ktype1 -f $OBJ/user_key1 || \ + fatal "ssh-keygen failed" +${SSHKEYGEN} -q -N '' -t $ktype2 -f $OBJ/user_key2 || \ + fatal "ssh-keygen failed" +${SSHKEYGEN} -q -N '' -t $ktype2 -f $OBJ/user_key3 || \ + fatal "ssh-keygen failed" +${SSHKEYGEN} -q -N '' -t $ktype4 -f $OBJ/user_key4 || \ + fatal "ssh-keygen failed" +${SSHKEYGEN} -q -N '' -t $ktype5 -f $OBJ/user_key5 || \ + fatal "ssh-keygen failed" +${SSHKEYGEN} -q -N '' -t $ktype6 -f $OBJ/user_key6 || \ + fatal "ssh-keygen failed" +${SSHKEYGEN} -q -s $OBJ/user_ca_key -I "regress user key for $USER" \ + -z $$ -n ${USER},mekmitasdigoat $OBJ/user_key3 || + fatal "couldn't sign user_key1" +# Copy the private key alongside the cert to allow better control of when +# it is offered. +mv $OBJ/user_key3-cert.pub $OBJ/cert_user_key3.pub + +grep -v IdentityFile $OBJ/ssh_proxy.orig > $OBJ/ssh_proxy + +opts="-oProtocol=2 -F $OBJ/ssh_proxy -oIdentitiesOnly=yes" +certopts="$opts -i $OBJ/user_key3 -oCertificateFile=$OBJ/cert_user_key3.pub" + +echo mekmitasdigoat > $OBJ/authorized_principals_$USER +cat $OBJ/user_key1.pub > $OBJ/authorized_keys_$USER +cat $OBJ/user_key2.pub >> $OBJ/authorized_keys_$USER + +prepare_config() { + ( + grep -v "Protocol" $OBJ/sshd_proxy.orig + echo "Protocol 2" + echo "AuthenticationMethods publickey" + echo "TrustedUserCAKeys $OBJ/user_ca_key.pub" + echo "AuthorizedPrincipalsFile $OBJ/authorized_principals_%u" + for x in "$@" ; do + echo "$x" + done + ) > $OBJ/sshd_proxy +} + +# Return the required parameter for PubkeyAcceptedAlgorithms corresponding to +# the supplied key type. +keytype() { + case "$1" in + ecdsa) printf "ecdsa-sha2-*" ;; + ed25519) printf "ssh-ed25519" ;; + dsa) printf "ssh-dss" ;; + rsa) printf "rsa-sha2-256,rsa-sha2-512,ssh-rsa" ;; + sk-ecdsa) printf "sk-ecdsa-*" ;; + sk-ssh-ed25519) printf "sk-ssh-ed25519-*" ;; + esac +} + +prepare_config + +# Check we can log in with all key types. +${SSH} $certopts proxy true || fatal "cert failed" +${SSH} $opts -i $OBJ/user_key1 proxy true || fatal "key1 failed" +${SSH} $opts -i $OBJ/user_key2 proxy true || fatal "key2 failed" + +# Allow plain Ed25519 and RSA. The certificate should fail. +verbose "allow $ktype2,$ktype1" +prepare_config \ + "PubkeyAcceptedAlgorithms `keytype $ktype2`,`keytype $ktype1`" +${SSH} $certopts proxy true && fatal "cert succeeded" +${SSH} $opts -i $OBJ/user_key1 proxy true || fatal "key1 failed" +${SSH} $opts -i $OBJ/user_key2 proxy true || fatal "key2 failed" + +# Allow Ed25519 only. +verbose "allow $ktype1" +prepare_config "PubkeyAcceptedAlgorithms `keytype $ktype1`" +${SSH} $certopts proxy true && fatal "cert succeeded" +${SSH} $opts -i $OBJ/user_key1 proxy true || fatal "key1 failed" +if [ "$ktype1" != "$ktype2" ]; then + ${SSH} $opts -i $OBJ/user_key2 proxy true && fatal "key2 succeeded" +fi + +# Allow all certs. Plain keys should fail. +verbose "allow cert only" +prepare_config "PubkeyAcceptedAlgorithms *-cert-v01@openssh.com" +${SSH} $certopts proxy true || fatal "cert failed" +${SSH} $opts -i $OBJ/user_key1 proxy true && fatal "key1 succeeded" +${SSH} $opts -i $OBJ/user_key2 proxy true && fatal "key2 succeeded" + +# Allow RSA in main config, Ed25519 for non-existent user. +verbose "match w/ no match" +prepare_config "PubkeyAcceptedAlgorithms `keytype $ktype2`" \ + "Match user x$USER" "PubkeyAcceptedAlgorithms +`keytype $ktype1`" +${SSH} $certopts proxy true && fatal "cert succeeded" +if [ "$ktype1" != "$ktype2" ]; then + ${SSH} $opts -i $OBJ/user_key1 proxy true && fatal "key1 succeeded" +fi +${SSH} $opts -i $OBJ/user_key2 proxy true || fatal "key2 failed" + +# Allow only DSA in main config, Ed25519 for user. +verbose "match w/ matching" +prepare_config "PubkeyAcceptedAlgorithms `keytype $ktype4`" \ + "Match user $USER" "PubkeyAcceptedAlgorithms +`keytype $ktype1`" +${SSH} $certopts proxy true || fatal "cert failed" +${SSH} $opts -i $OBJ/user_key1 proxy true || fatal "key1 failed" +${SSH} $opts -i $OBJ/user_key4 proxy true && fatal "key4 succeeded" + |