From 55cf09a02b6f86c15b41395010a2b6b7a8eda7c7 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Wed, 27 Feb 2019 14:57:54 +0000 Subject: vnc: allow specifying a custom authorization object name The VNC server has historically had support for ACLs to check both the SASL username and the TLS x509 distinguished name. The VNC server was responsible for creating the initial ACL, and the client app was then responsible for populating it with rules using the HMP 'acl_add' command. This is not satisfactory for a variety of reasons. There is no way to populate the ACLs from the command line, users are forced to use the HMP. With multiple network services all supporting TLS and ACLs now, it is desirable to be able to define a single ACL that is referenced by all services. To address these limitations, two new options are added to the VNC server CLI. The 'tls-authz' option takes the ID of a QAuthZ object to use for checking TLS x509 distinguished names, and the 'sasl-authz' option takes the ID of another object to use for checking SASL usernames. In this example, we setup two authorization rules. The first allows any client with a certificate issued by the 'RedHat' organization in the 'London' locality. The second ACL allows clients with either the 'joe@REDHAT.COM' or 'fred@REDHAT.COM' kerberos usernames. Both checks must pass for the user to be allowed. $QEMU -object tls-creds-x509,id=tls0,dir=/home/berrange/qemutls,\ endpoint=server,verify-peer=yes \ -object authz-simple,id=authz0,policy=deny,\ rules.0.match=O=RedHat,,L=London,rules.0.policy=allow \ -object authz-simple,id=authz1,policy=deny,\ rules.0.match=fred@REDHAT.COM,rules.0.policy=allow \ rules.0.match=joe@REDHAT.COM,rules.0.policy=allow \ -vnc 0.0.0.0:1,tls-creds=tls0,tls-authz=authz0, sasl,sasl-authz=authz1 \ ...other QEMU args... Reviewed-by: Juan Quintela Signed-off-by: Daniel P. Berrange Message-id: 20190227145755.26556-2-berrange@redhat.com Signed-off-by: Gerd Hoffmann --- ui/vnc.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 49 insertions(+), 9 deletions(-) (limited to 'ui') diff --git a/ui/vnc.c b/ui/vnc.c index 2f2ab62..2d9e8f4 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -3364,6 +3364,12 @@ static QemuOptsList qemu_vnc_opts = { .name = "acl", .type = QEMU_OPT_BOOL, },{ + .name = "tls-authz", + .type = QEMU_OPT_STRING, + },{ + .name = "sasl-authz", + .type = QEMU_OPT_STRING, + },{ .name = "lossy", .type = QEMU_OPT_BOOL, },{ @@ -3802,6 +3808,8 @@ void vnc_display_open(const char *id, Error **errp) const char *credid; bool sasl = false; int acl = 0; + const char *tlsauthz; + const char *saslauthz; int lock_key_sync = 1; int key_delay_ms; @@ -3873,7 +3881,33 @@ void vnc_display_open(const char *id, Error **errp) goto fail; } } + if (qemu_opt_get(opts, "acl")) { + error_report("The 'acl' option to -vnc is deprecated. " + "Please use the 'tls-authz' and 'sasl-authz' " + "options instead"); + } acl = qemu_opt_get_bool(opts, "acl", false); + tlsauthz = qemu_opt_get(opts, "tls-authz"); + if (acl && tlsauthz) { + error_setg(errp, "'acl' option is mutually exclusive with the " + "'tls-authz' option"); + goto fail; + } + if (tlsauthz && !vd->tlscreds) { + error_setg(errp, "'tls-authz' provided but TLS is not enabled"); + goto fail; + } + + saslauthz = qemu_opt_get(opts, "sasl-authz"); + if (acl && saslauthz) { + error_setg(errp, "'acl' option is mutually exclusive with the " + "'sasl-authz' option"); + goto fail; + } + if (saslauthz && !sasl) { + error_setg(errp, "'sasl-authz' provided but SASL auth is not enabled"); + goto fail; + } share = qemu_opt_get(opts, "share"); if (share) { @@ -3903,7 +3937,9 @@ void vnc_display_open(const char *id, Error **errp) vd->non_adaptive = true; } - if (acl) { + if (tlsauthz) { + vd->tlsauthzid = g_strdup(tlsauthz); + } else if (acl) { if (strcmp(vd->id, "default") == 0) { vd->tlsauthzid = g_strdup("vnc.x509dname"); } else { @@ -3914,15 +3950,19 @@ void vnc_display_open(const char *id, Error **errp) &error_abort)); } #ifdef CONFIG_VNC_SASL - if (acl && sasl) { - if (strcmp(vd->id, "default") == 0) { - vd->sasl.authzid = g_strdup("vnc.username"); - } else { - vd->sasl.authzid = g_strdup_printf("vnc.%s.username", vd->id); + if (sasl) { + if (saslauthz) { + vd->sasl.authzid = g_strdup(saslauthz); + } else if (acl) { + if (strcmp(vd->id, "default") == 0) { + vd->sasl.authzid = g_strdup("vnc.username"); + } else { + vd->sasl.authzid = g_strdup_printf("vnc.%s.username", vd->id); + } + vd->sasl.authz = QAUTHZ(qauthz_list_new(vd->sasl.authzid, + QAUTHZ_LIST_POLICY_DENY, + &error_abort)); } - vd->sasl.authz = QAUTHZ(qauthz_list_new(vd->sasl.authzid, - QAUTHZ_LIST_POLICY_DENY, - &error_abort)); } #endif -- cgit v1.1