tests/qemu-iotests: validate NBD TLS with hostname mismatch

This validates that connections to an NBD server where the certificate
hostname does not match will fail. It further validates that using the
new 'tls-hostname' override option can solve the failure.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220304193610.3293146-11-berrange@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

tests/qemu-iotests/233

@@ -106,6 +106,24 @@ $QEMU_IMG info --image-opts --object $obj2 \
 $QEMU_NBD_PROG -L -b $nbd_tcp_addr -p $nbd_tcp_port --object $obj1 \
     --tls-creds=tls0 2>&1 | _filter_qemu_nbd_exports
 
+echo
+echo "== check TLS fail over TCP with mismatched hostname =="
+obj1=tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0
+$QEMU_IMG info --image-opts --object $obj1 \
+    driver=nbd,host=localhost,port=$nbd_tcp_port,tls-creds=tls0 \
+    2>&1 | _filter_nbd
+$QEMU_NBD_PROG -L -b localhost -p $nbd_tcp_port --object $obj1 \
+    --tls-creds=tls0 | _filter_qemu_nbd_exports
+
+echo
+echo "== check TLS works over TCP with mismatched hostname and override =="
+obj1=tls-creds-x509,dir=${tls_dir}/client1,endpoint=client,id=tls0
+$QEMU_IMG info --image-opts --object $obj1 \
+    driver=nbd,host=localhost,port=$nbd_tcp_port,tls-creds=tls0,tls-hostname=127.0.0.1 \
+    2>&1 | _filter_nbd
+$QEMU_NBD_PROG -L -b localhost -p $nbd_tcp_port --object $obj1 \
+    --tls-creds=tls0 --tls-hostname=127.0.0.1 | _filter_qemu_nbd_exports
+
 echo
 echo "== check TLS with different CA fails =="
 obj=tls-creds-x509,dir=${tls_dir}/client2,endpoint=client,id=tls0

tests/qemu-iotests/233.out

@@ -38,6 +38,20 @@ exports available: 1
   size:  67108864
   min block: 1
 
+== check TLS fail over TCP with mismatched hostname ==
+qemu-img: Could not open 'driver=nbd,host=localhost,port=PORT,tls-creds=tls0': Certificate does not match the hostname localhost
+qemu-nbd: Certificate does not match the hostname localhost
+
+== check TLS works over TCP with mismatched hostname and override ==
+image: nbd://localhost:PORT
+file format: nbd
+virtual size: 64 MiB (67108864 bytes)
+disk size: unavailable
+exports available: 1
+ export: ''
+  size:  67108864
+  min block: 1
+
 == check TLS with different CA fails ==
 qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': The certificate hasn't got a known issuer
 qemu-nbd: The certificate hasn't got a known issuer
@@ -55,6 +69,8 @@ qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': F
 qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': Failed to read option reply: Cannot read from TLS channel: Software caused connection abort
 
 == final server log ==
+qemu-nbd: option negotiation failed: Failed to read opts magic: Cannot read from TLS channel: Software caused connection abort
+qemu-nbd: option negotiation failed: Failed to read opts magic: Cannot read from TLS channel: Software caused connection abort
 qemu-nbd: option negotiation failed: Verify failed: No certificate was found.
 qemu-nbd: option negotiation failed: Verify failed: No certificate was found.
 qemu-nbd: option negotiation failed: TLS x509 authz check for DISTINGUISHED-NAME is denied

tests/qemu-iotests/common.tls

@@ -118,12 +118,13 @@ tls_x509_create_server()
     caname=$1
     name=$2
 
+    # We don't include 'localhost' in the cert, as
+    # we want to keep it unlisted to let tests
+    # validate hostname override
     mkdir -p "${tls_dir}/$name"
     cat > "${tls_dir}/cert.info" <<EOF
 organization = Cthulhu Dark Lord Enterprises $name
-cn = localhost
+cn = iotests.qemu.org
-dns_name = localhost
-dns_name = localhost.localdomain
 ip_address = 127.0.0.1
 ip_address = ::1
 tls_www_server