From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:56240) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gyzgo-0007ab-C9 for qemu-devel@nongnu.org; Wed, 27 Feb 2019 08:56:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gyzgm-0005S3-OO for qemu-devel@nongnu.org; Wed, 27 Feb 2019 08:56:02 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48670) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gyzgc-0005LD-BJ for qemu-devel@nongnu.org; Wed, 27 Feb 2019 08:55:53 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EA7E840220 for ; Wed, 27 Feb 2019 13:55:47 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Wed, 27 Feb 2019 13:55:23 +0000 Message-Id: <20190227135523.16952-2-berrange@redhat.com> In-Reply-To: <20190227135523.16952-1-berrange@redhat.com> References: <20190227135523.16952-1-berrange@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH 1/1] chardev: add support for authorization for TLS clients List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Markus Armbruster , Paolo Bonzini , Eric Blake , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , "Daniel P. Berrange" From: "Daniel P. Berrange" 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=3DOBJECT-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=3Dfred', yo= u would use: $QEMU -object tls-creds-x509,id=3Dtls0,dir=3D/home/berrange/qemutls,\ endpoint=3Dserver,verify-peer=3Dyes \ -object authz-simple,id=3Dauthz0,identity=3DCN=3Dlaptop.example.c= om,,\ O=3DExample Org,,L=3DLondon,,ST=3DLondon,,C=3DGB \ -chardev socket,host=3D127.0.0.1,port=3D9000,server,\ tls-creds=3Dtls0,tls-authz=3Dauthz0 \ ...other qemu args... Signed-off-by: Daniel P. Berrange --- chardev/char-socket.c | 12 +++++++++++- chardev/char.c | 3 +++ qapi/char.json | 6 ++++++ qemu-options.hx | 9 +++++++-- 4 files changed, 27 insertions(+), 3 deletions(-) diff --git a/chardev/char-socket.c b/chardev/char-socket.c index 4fcdd8aedd..12e78426aa 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 =3D qio_channel_tls_new_server( s->ioc, s->tls_creds, - NULL, /* XXX Use an ACL */ + s->tls_authz, &err); } else { tioc =3D 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); =20 qemu_chr_be_event(chr, CHR_EVENT_CLOSED); } @@ -1242,6 +1244,11 @@ static bool qmp_chardev_validate_socket(ChardevSoc= ket *sock, break; } =20 + 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 =3D g_strdup(sock->tls_authz); =20 s->addr =3D addr =3D socket_address_flatten(sock->addr); =20 @@ -1399,6 +1407,8 @@ static void qemu_chr_parse_socket(QemuOpts *opts, C= hardevBackend *backend, sock->reconnect =3D qemu_opt_get_number(opts, "reconnect", 0); sock->has_tls_creds =3D qemu_opt_get(opts, "tls-creds"); sock->tls_creds =3D g_strdup(qemu_opt_get(opts, "tls-creds")); + sock->has_tls_authz =3D qemu_opt_get(opts, "tls-authz"); + sock->tls_authz =3D g_strdup(qemu_opt_get(opts, "tls-authz")); =20 addr =3D g_new0(SocketAddressLegacy, 1); if (path) { diff --git a/chardev/char.c b/chardev/char.c index f6d61fa5f8..514cd6b0c3 100644 --- a/chardev/char.c +++ b/chardev/char.c @@ -880,6 +880,9 @@ QemuOptsList qemu_chardev_opts =3D { },{ .name =3D "tls-creds", .type =3D QEMU_OPT_STRING, + },{ + .name =3D "tls-authz", + .type =3D QEMU_OPT_STRING, },{ .name =3D "websocket", .type =3D QEMU_OPT_BOOL, diff --git a/qapi/char.json b/qapi/char.json index 77ed847972..7847c98d05 100644 --- a/qapi/char.json +++ b/qapi/char.json @@ -248,6 +248,11 @@ # @addr: socket address to listen on (server=3Dtrue) # or connect to (server=3Dfalse) # @tls-creds: the ID of the TLS credentials object (since 2.6) +# @tls-authz: the ID of the QAuthZ authorization object against which +# the client's x509 distinguished name will validated. This +# object is only resolved at time of use, so can be deleted +# and recreated on the fly while the chardev server is activ= e. +# If missing, it will default to denying access (since 4.0) # @server: create server socket (default: true) # @wait: wait for incoming connection on server # sockets (default: false). @@ -268,6 +273,7 @@ { 'struct': 'ChardevSocket', 'data': { 'addr': 'SocketAddressLegacy', '*tls-creds': 'str', + '*tls-authz' : 'str', '*server': 'bool', '*wait': 'bool', '*nodelay': 'bool', diff --git a/qemu-options.hx b/qemu-options.hx index 1cf9aac1fe..aecbb2ca9c 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2413,7 +2413,7 @@ DEF("chardev", HAS_ARG, QEMU_OPTION_chardev, "-chardev null,id=3Did[,mux=3Don|off][,logfile=3DPATH][,logappend=3D= on|off]\n" "-chardev socket,id=3Did[,host=3Dhost],port=3Dport[,to=3Dto][,ipv4][= ,ipv6][,nodelay][,reconnect=3Dseconds]\n" " [,server][,nowait][,telnet][,websocket][,reconnect=3Dsecon= ds][,mux=3Don|off]\n" - " [,logfile=3DPATH][,logappend=3Don|off][,tls-creds=3DID] (t= cp)\n" + " [,logfile=3DPATH][,logappend=3Don|off][,tls-creds=3DID][,t= ls-authz=3DID] (tcp)\n" "-chardev socket,id=3Did,path=3Dpath[,server][,nowait][,telnet][,web= socket][,reconnect=3Dseconds]\n" " [,mux=3Don|off][,logfile=3DPATH][,logappend=3Don|off] (uni= x)\n" "-chardev udp,id=3Did[,host=3Dhost],port=3Dport[,localaddr=3Dlocalad= dr]\n" @@ -2542,7 +2542,7 @@ The available backends are: A void device. This device will not emit any data, and will drop any dat= a it receives. The null backend does not take any options. =20 -@item -chardev socket,id=3D@var{id}[,@var{TCP options} or @var{unix opti= ons}][,server][,nowait][,telnet][,websocket][,reconnect=3D@var{seconds}][= ,tls-creds=3D@var{id}] +@item -chardev socket,id=3D@var{id}[,@var{TCP options} or @var{unix opti= ons}][,server][,nowait][,telnet][,websocket][,reconnect=3D@var{seconds}][= ,tls-creds=3D@var{id}][,tls-authz=3D@var{id}] =20 Create a two-way stream socket, which can be either a TCP or a unix sock= et. A unix socket will be created if @option{path} is specified. Behaviour is @@ -2568,6 +2568,11 @@ and specifies the id of the TLS credentials to use= for the handshake. The credentials must be previously created with the @option{-object tls-cred= s} argument. =20 +@option{tls-auth} provides the ID of the QAuthZ authorization object aga= inst +which the client's x509 distinguished name will validated. This object i= s only +resolved at time of use, so can be deleted and recreated on the fly whil= e the +chardev server is active. If missing, it will default to denying access. + TCP and unix socket options are given below: =20 @table @option --=20 2.20.1