feat: IPv6 support

bin/shell/osh.pl

@@ -600,8 +600,7 @@ sub main_exit {
 if ($user && !OVH::Bastion::is_valid_remote_user(user => $user, allowWildcards => ($osh_command ? 1 : 0))) {
     main_exit OVH::Bastion::EXIT_INVALID_REMOTE_USER, 'invalid_remote_user', "Remote user name '$user' seems invalid";
 }
-if ($host && $host !~ m{^[a-zA-Z0-9._/:-]+$}) {
-
+if ($host && $host !~ m{^\[?[a-zA-Z0-9._/:-]+\]?$}) {
     # can be an IP (v4 or v6), hostname, or prefix (with a /)
     main_exit OVH::Bastion::EXIT_INVALID_REMOTE_HOST, 'invalid_remote_host', "Remote host name '$host' seems invalid";
 }
@@ -612,7 +611,6 @@ sub main_exit {
 
 # if: avoid loading Net::IP and BigInt if there's no host specified
 if ($host) {
-
     # probably this "host" is in fact an option, but we didn't parse it because it's an unknown one,
     # so we call the long_help() for the user, before exiting
     if ($host =~ m{^--}) {
@@ -624,14 +622,17 @@ sub main_exit {
     $fnret = OVH::Bastion::get_ip(host => $host);
 }
 if (!$fnret) {
-
-    # exit error when not osh ...
+    # exit error when not a plugin call
     if (!$osh_command) {
-        main_exit OVH::Bastion::EXIT_HOST_NOT_FOUND, 'host_not_found', "Unable to resolve host '$host' ($fnret)";
+        main_exit OVH::Bastion::EXIT_HOST_NOT_FOUND, 'host_not_found', $fnret->msg;
     }
     elsif ($host && $host !~ m{^[0-9.:]+/\d+$})    # in some osh plugins, ip/mask is accepted, don't yell.
     {
-        osh_warn("I was unable to resolve host '$host'. Something shitty might happen.");
+        osh_warn($fnret->msg);
+        osh_warn("Trying to proceed with $osh_command anyway, but things might go wrong.");
+        if (index($host, ':') >= 0 && !OVH::Bastion::config('IPv6Allowed')->value) {
+            osh_warn("Note that '$host' looks like an IPv6 but IPv6 support has not been enabled.");
+        }
     }
 }
 else {

doc/sphinx/administration/configuration/bastion_conf.rst

@@ -51,6 +51,8 @@ Those options can set a few global network policies to be applied bastion-wide.
 - `allowedNetworks`_
 - `forbiddenNetworks`_
 - `ingressToEgressRules`_
+- `IPv4Allowed`_
+- `IPv6Allowed`_
 
 Logging options
 ---------------
@@ -426,6 +428,28 @@ For example, take the following configuration:
 
 In any case, all the personal and group accesses still apply in addition to these global rules.
 
+.. _IPv4Allowed:
+
+IPv4Allowed
+***********
+
+:Type: ``boolean``
+
+:Default: ``true``
+
+If enabled, IPv4 egress connections will be allowed, and IPv4 will be enabled in the DNS queries. This is the default. Do NOT disable this unless you enable IPv6Allowed, if you need to have an IPv6-only bastion.
+
+.. _IPv6Allowed:
+
+IPv6Allowed
+***********
+
+:Type: ``boolean``
+
+:Default: ``false``
+
+If enabled, IPv6 egress connections will be allowed, and IPv6 will be enabled in the DNS queries. By default, only IPv4 is allowed.
+
 Logging
 -------
 

etc/bastion/bastion.conf.dist

@@ -173,6 +173,16 @@
 #  DEFAULT: []
 "ingressToEgressRules": [],
 #
+# IPv4Allowed (boolean)
+#    DESC: If enabled, IPv4 egress connections will be allowed, and IPv4 will be enabled in the DNS queries. This is the default. Do NOT disable this unless you enable IPv6Allowed, if you need to have an IPv6-only bastion.
+# DEFAULT: true
+"IPv4Allowed": true,
+#
+# IPv6Allowed (boolean)
+#    DESC: If enabled, IPv6 egress connections will be allowed, and IPv6 will be enabled in the DNS queries. By default, only IPv4 is allowed.
+# DEFAULT: false
+"IPv6Allowed": false,
+#
 ###########
 # > Logging
 # >> Options to customize how logs should be produced.

lib/perl/OVH/Bastion.pm

@@ -700,15 +700,26 @@ sub is_valid_ip {
         return R('KO_INVALID_IP', msg => "Invalid IP address ($ip)");
     }
 
-    my $shortip = $IpObject->prefix;
-
-    # if /32 or /128, omit the /prefixlen on $shortip
-    my $type = 'prefix';
-    if (   ($IpObject->version == 4 and $IpObject->prefixlen == 32)
-        or ($IpObject->version == 6 and $IpObject->prefixlen == 128))
-    {
-        $shortip =~ s'/\d+$'';
-        $type = 'single';
+    my ($shortip, $type);
+    if ($IpObject->version == 4) {
+        if ($IpObject->prefixlen == 32) {
+            $shortip = $IpObject->ip;
+            $type    = 'single';
+        }
+        else {
+            $shortip = $IpObject->prefix;
+            $type    = 'prefix';
+        }
+    }
+    elsif ($IpObject->version == 6) {
+        if ($IpObject->prefixlen == 128) {
+            $shortip = $IpObject->short;
+            $type    = 'single';
+        }
+        else {
+            $shortip = $IpObject->short . '/' . $IpObject->prefixlen;
+            $type    = 'prefix';
+        }
     }
 
     if (not $allowPrefixes and $type eq 'prefix') {
@@ -1125,6 +1136,12 @@ sub build_ttyrec_cmdline_part1of2 {
         return R('ERR_MISSING_PARAMETER', msg => "Missing ip parameter");
     }
 
+    # if ip is an IPv6, replace :'s by .'s and surround by v6[]'s (which is allowed on all filesystems)
+    if ($params{'ip'} && index($params{'ip'}, ':') >= 0) {
+        $params{'ip'} =~ tr/:/./;
+        $params{'ip'} = 'v6[' . $params{'ip'} . ']';
+    }
+
     # build ttyrec filename format
     my $bastionName          = OVH::Bastion::config('bastionName')->value;
     my $ttyrecFilenameFormat = OVH::Bastion::config('ttyrecFilenameFormat')->value;

lib/perl/OVH/Bastion/allowdeny.inc

@@ -280,19 +280,19 @@ sub is_access_way_granted {
 sub get_ip {
     my %params = @_;
     my $host   = $params{'host'};
-    my $v4     = $params{'v4'};     # allow ipv4 ?
-    my $v6     = $params{'v6'};     # allow ipv6 ?
+    my $v4     = $params{'v4'} // OVH::Bastion::config('IPv4Allowed')->value;
+    my $v6     = $params{'v6'} // OVH::Bastion::config('IPv6Allowed')->value;
 
     if (!$host) {
         return R('ERR_MISSING_PARAMETER', msg => "Missing parameter 'host'");
     }
 
-    # by default, only v4 unless specified otherwise
-    $v4 = 1 if not defined $v4;
-    $v6 = 0 if not defined $v6;
+    # if v4 or v6 are disabled in config, force-disable them here too
+    $v4 = 0 if !OVH::Bastion::config('IPv4Allowed')->value;
+    $v6 = 0 if !OVH::Bastion::config('IPv6Allowed')->value;
 
     # try to see if it's already an IP
-    osh_debug("checking if '$host' is already an IP");
+    osh_debug("checking if '$host' is already an IP (v4=$v4 v6=$v6)");
     my $fnret = OVH::Bastion::is_valid_ip(ip => $host, allowPrefixes => 0);
     if ($fnret) {
         osh_debug("Host $host is already an IP");
@@ -301,34 +301,41 @@ sub get_ip {
         {
             return R('OK', value => {ip => $fnret->value->{'ip'}, iplist => [$fnret->value->{'ip'}]});
         }
-        return R('ERR_INVALID_IP', msg => "IP $host version is not allowed");
+        return R('ERR_INVALID_IP', msg => "IP $host version (IPv" . $fnret->value->{'version'} . ") is not allowed");
     }
 
     if (OVH::Bastion::config('dnsSupportLevel')->value < 1) {
         return R('ERR_DNS_DISABLED', msg => "DNS resolving is disabled on this bastion");
     }
 
     osh_debug("Trying to resolve '$host' because is_valid_ip() says it's not an IP");
-    my ($err, @res);
-    eval {
+    my ($err, @res) = eval {
         # dns resolving, v4/v6 compatible
         # can croak
-        ($err, @res) = getaddrinfo($host, undef, {socktype => SOCK_STREAM});
+        getaddrinfo($host, undef, {socktype => SOCK_STREAM});
     };
-    return R('ERR_HOST_NOT_FOUND', msg => $@)   if $@;
-    return R('ERR_HOST_NOT_FOUND', msg => $err) if $err;
+    return R('ERR_HOST_NOT_FOUND', msg => "Unable to resolve '$host' ($@)")   if $@;
+    return R('ERR_HOST_NOT_FOUND', msg => "Unable to resolve '$host' ($err)") if $err;
 
     my %iplist;
     my $lastip;
+    my $skippedcount = 0;
     foreach my $item (@res) {
         if ($item->{'family'} == AF_INET) {
-            next if not $v4;
+            if (!$v4) {
+                $skippedcount++;
+                next;
+            }
         }
         elsif ($item->{'family'} == AF_INET6) {
-            next if not $v6;
+            if (!$v6) {
+                $skippedcount++;
+                next;
+            }
         }
         else {
             # unknown weird family ?
+            $skippedcount++;
             next;
         }
         my $as_text;
@@ -347,6 +354,9 @@ sub get_ip {
     }
 
     # %iplist empty, not resolved (?)
+    return R('ERR_HOST_NOT_FOUND',
+        msg => "Unable to resolve '$host' (some IPv4 and/or IPv6 were skipped due to policy)")
+      if $skippedcount;
     return R('ERR_HOST_NOT_FOUND', msg => "Unable to resolve '$host'");
 }
 

lib/perl/OVH/Bastion/allowkeeper.inc

@@ -592,11 +592,9 @@ sub access_modify {
 
         # if we're adding it, append other parameters as comments
         if ($action eq 'add') {
-
             $entry .= " $entryComment";
 
             if ($forceKey) {
-
                 # hash is case-sensitive only for new SHA256 format
                 $forceKey = lc($forceKey) if ($forceKey !~ /^sha256:/i);
                 $entry .= " # FORCEKEY=" . $forceKey;

lib/perl/OVH/Bastion/configuration.inc

@@ -265,7 +265,7 @@ sub load_configuration {
             options => [
                 qw{
                   enableSyslog enableGlobalAccessLog enableAccountAccessLog enableGlobalSqlLog enableAccountSqlLog displayLastLogin
-                  interactiveModeByDefault interactiveModeProactiveMFAenabled
+                  interactiveModeByDefault interactiveModeProactiveMFAenabled IPv4Allowed
                   }
             ],
         },
@@ -275,7 +275,7 @@ sub load_configuration {
                 qw{
                   interactiveModeAllowed readOnlySlaveMode sshClientHasOptionE ingressKeysFromAllowOverride
                   moshAllowed debug keyboardInteractiveAllowed passwordAllowed telnetAllowed remoteCommandEscapeByDefault
-                  accountExternalValidationDenyOnFailure ingressRequirePIV
+                  accountExternalValidationDenyOnFailure ingressRequirePIV IPv6Allowed
                   }
             ],
         }

tests/functional/docker/docker_build_and_run_tests.sh

@@ -123,7 +123,13 @@ docker rm -f "bastion_${target}_tester" 2>/dev/null || true
 if docker inspect "bastion-$target" >/dev/null 2>&1; then
     docker network rm "bastion-$target" >/dev/null
 fi
-docker network create "bastion-$target" >/dev/null
+
+# trying with IPv6
+if ! docker network create --ipv6 --subnet fd42:cafe:efac:"$(printf "%x" $RANDOM)"::/64 "bastion-$target" >/dev/null; then
+    # didn't work... retry without IPv6
+    echo "... IPv6 is not enabled in docker daemon, falling back to IPv4-only network"
+    docker network create "bastion-$target" >/dev/null
+fi
 
 # run target but force entrypoint to test one, and add some keys in env (will be shared with tester)
 echo "Starting target instance"

tests/functional/docker/target_role.sh

@@ -125,7 +125,7 @@ if [ "$OS_FAMILY" = Linux ] ; then
 
 elif [ "$OS_FAMILY" = OpenBSD ] || [  "$OS_FAMILY" = FreeBSD ] || [ "$OS_FAMILY" = NetBSD ] ; then
     # setup some 127.0.0.x IPs (needed for our tests)
-    # this automatically works under Linux on lo
+    # this is not required under Linux where all IPs of 127.0.0.0/8 implicitely work
     nic=$(ifconfig | perl -ne 'm{^([a-z._0-9]+): flags}i and $nic=$1; m{inet 127\.0\.0\.1} and print $nic and exit')
     : "${nic:=lo0}"
     i=2

tests/functional/tests.d/395-mfa-scp-sftp-rsync.sh

@@ -152,11 +152,11 @@ EOF
 
     run invalidhostname_scp_oldhelper scp $scp_options -F $mytmpdir/ssh_config -S /tmp/scphelper -i $account0key1file $shellaccount@_invalid._invalid:uptest /tmp/downloaded
     retvalshouldbe 1
-    contain REGEX "Sorry, couldn't resolve the host you specified|I was unable to resolve host"
+    contain REGEX "Sorry, couldn't resolve the host you specified|I was unable to resolve host|Unable to resolve host"
 
     run invalidhostname_scp_newwrapper /tmp/scpwrapper -i $account0key1file $shellaccount@_invalid._invalid:uptest /tmp/downloaded
     retvalshouldbe 1
-    contain REGEX "Sorry, couldn't resolve the host you specified|I was unable to resolve host"
+    contain REGEX "Sorry, couldn't resolve the host you specified|I was unable to resolve host|Unable to resolve host"
 
     success personal_scp_upload_oldhelper_ok scp $scp_options -F $mytmpdir/ssh_config -S /tmp/scphelper -i $account0key1file /etc/passwd [email protected]:uptest
     contain "through the bastion to"