From fd4a5fd4639bb1bfd04144fca85856d825e00ab4 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Fri, 8 Mar 2019 15:21:50 +0000 Subject: chardev: add support for authorization for TLS clients MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently any client which can complete the TLS handshake is able to use a chardev server. The server admin can turn on the 'verify-peer' option for the x509 creds to require the client to provide a x509 certificate. This means the client will have to acquire a certificate from the CA before they are permitted to use the chardev server. This is still a fairly low bar. This adds a 'tls-authz=OBJECT-ID' option to the socket chardev backend which takes the ID of a previously added 'QAuthZ' object instance. This will be used to validate the client's x509 distinguished name. Clients failing the check will not be permitted to use the chardev server. For example to setup authorization that only allows connection from a client whose x509 certificate distinguished name contains 'CN=fred', you would use: $QEMU -object tls-creds-x509,id=tls0,dir=/home/berrange/qemutls,\ endpoint=server,verify-peer=yes \ -object authz-simple,id=authz0,identity=CN=laptop.example.com,,\ O=Example Org,,L=London,,ST=London,,C=GB \ -chardev socket,host=127.0.0.1,port=9000,server,\ tls-creds=tls0,tls-authz=authz0 \ ...other qemu args... Signed-off-by: Daniel P. Berrange Reviewed-by: Marc-André Lureau --- chardev/char-socket.c | 12 +++++++++++- chardev/char.c | 3 +++ 2 files changed, 14 insertions(+), 1 deletion(-) (limited to 'chardev') diff --git a/chardev/char-socket.c b/chardev/char-socket.c index 6d287ba..3916505 100644 --- a/chardev/char-socket.c +++ b/chardev/char-socket.c @@ -59,6 +59,7 @@ typedef struct { QIONetListener *listener; GSource *hup_source; QCryptoTLSCreds *tls_creds; + char *tls_authz; TCPChardevState state; int max_size; int do_telnetopt; @@ -807,7 +808,7 @@ static void tcp_chr_tls_init(Chardev *chr) if (s->is_listen) { tioc = qio_channel_tls_new_server( s->ioc, s->tls_creds, - NULL, /* XXX Use an ACL */ + s->tls_authz, &err); } else { tioc = qio_channel_tls_new_client( @@ -1055,6 +1056,7 @@ static void char_socket_finalize(Object *obj) if (s->tls_creds) { object_unref(OBJECT(s->tls_creds)); } + g_free(s->tls_authz); qemu_chr_be_event(chr, CHR_EVENT_CLOSED); } @@ -1242,6 +1244,11 @@ static bool qmp_chardev_validate_socket(ChardevSocket *sock, break; } + if (sock->has_tls_authz && !sock->has_tls_creds) { + error_setg(errp, "'tls_authz' option requires 'tls_creds' option"); + return false; + } + /* Validate any options which have a dependancy on client vs server */ if (!sock->has_server || sock->server) { if (sock->has_reconnect) { @@ -1320,6 +1327,7 @@ static void qmp_chardev_open_socket(Chardev *chr, } } } + s->tls_authz = g_strdup(sock->tls_authz); s->addr = addr = socket_address_flatten(sock->addr); @@ -1399,6 +1407,8 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend, sock->reconnect = qemu_opt_get_number(opts, "reconnect", 0); sock->has_tls_creds = qemu_opt_get(opts, "tls-creds"); sock->tls_creds = g_strdup(qemu_opt_get(opts, "tls-creds")); + sock->has_tls_authz = qemu_opt_get(opts, "tls-authz"); + sock->tls_authz = g_strdup(qemu_opt_get(opts, "tls-authz")); addr = g_new0(SocketAddressLegacy, 1); if (path) { diff --git a/chardev/char.c b/chardev/char.c index f6d61fa..514cd6b 100644 --- a/chardev/char.c +++ b/chardev/char.c @@ -881,6 +881,9 @@ QemuOptsList qemu_chardev_opts = { .name = "tls-creds", .type = QEMU_OPT_STRING, },{ + .name = "tls-authz", + .type = QEMU_OPT_STRING, + },{ .name = "websocket", .type = QEMU_OPT_BOOL, },{ -- cgit v1.1