Re: [Qemu-devel] PATCH: 5/7: Include auth credentials in 'info vnc'

["Daniel P. Berrange" <berrange@redhat.com>]

This patch extends the 'info vnc' monitor output to include information
about the VNC client authentication credentials.

For clients authenticated using SASL, this will output the username.

For clients authenticated using x509 certificates, this will output
the x509 distinguished name.

Auth can be stacked, so both username & x509 dname may be shown.


  (qemu) info vnc
  Server: active
       address: 0.0.0.0:5901
          auth: vencrypt+x509+sasl
  Client: active
       address: 127.0.0.1:42956
    x509 dname: C=GB,O=Red Hat,L=London,ST=London,CN=localhost
      username: test


   Signed-off-by: Daniel P. Berrange <berrange@redhat.com>


 vnc-tls.c |   17 +++++++++++++++++
 vnc-tls.h |    3 +++
 vnc.c     |   19 +++++++++++++++++--
 3 files changed, 37 insertions(+), 2 deletions(-)

Daniel

diff -r 122f8a90f465 vnc-tls.c
--- a/vnc-tls.c	Wed Feb 11 17:34:08 2009 +0000
+++ b/vnc-tls.c	Wed Feb 11 17:34:11 2009 +0000
@@ -241,6 +241,22 @@ int vnc_tls_validate_certificate(struct 
 	    return -1;
 	}
 
+	if (i == 0) {
+	    size_t dnameSize = 1024;
+	    vs->tls.dname = qemu_malloc(dnameSize);
+	requery:
+	    if ((ret = gnutls_x509_crt_get_dn (cert, vs->tls.dname, &dnameSize)) != 0) {
+		if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER) {
+		    vs->tls.dname = qemu_realloc(vs->tls.dname, dnameSize);
+		    goto requery;
+		}
+		gnutls_x509_crt_deinit (cert);
+		VNC_DEBUG("Cannot get client distinguished name: %s",
+			  gnutls_strerror (ret));
+		return -1;
+	    }
+	}
+
 	gnutls_x509_crt_deinit (cert);
     }
 
@@ -346,6 +362,7 @@ void vnc_tls_client_cleanup(struct VncSt
 	vs->tls.session = NULL;
     }
     vs->tls.wiremode = VNC_WIREMODE_CLEAR;
+    free(vs->tls.dname);
 }
 
 
diff -r 122f8a90f465 vnc-tls.h
--- a/vnc-tls.h	Wed Feb 11 17:34:08 2009 +0000
+++ b/vnc-tls.h	Wed Feb 11 17:34:11 2009 +0000
@@ -48,6 +48,9 @@ struct VncStateTLS {
     /* Whether data is being TLS encrypted yet */
     int wiremode;
     gnutls_session_t session;
+
+    /* Client's Distinguished Name from the x509 cert */
+    char *dname;
 };
 
 int vnc_tls_client_setup(VncState *vs, int x509Creds);
diff -r 122f8a90f465 vnc.c
--- a/vnc.c	Wed Feb 11 17:34:08 2009 +0000
+++ b/vnc.c	Wed Feb 11 17:34:11 2009 +0000
@@ -176,6 +176,21 @@ void do_info_vnc(void)
 	    term_puts("Client: active\n");
 	    term_puts(clientAddr);
 	    free(clientAddr);
+
+#ifdef CONFIG_VNC_TLS
+	    if (vnc_state->tls.session &&
+		vnc_state->tls.dname)
+		term_printf("  x509 dname: %s\n", vnc_state->tls.dname);
+	    else
+		term_puts("  x509 dname: none\n");
+#endif
+#ifdef CONFIG_VNC_SASL
+	    if (vnc_state->sasl.conn &&
+		vnc_state->sasl.username)
+		term_printf("    username: %s\n", vnc_state->sasl.username);
+	    else
+		term_puts("    username: none\n");
+#endif
 	}
     }
 }
@@ -1781,7 +1796,7 @@ static int protocol_client_auth(VncState
     /* We only advertise 1 auth scheme at a time, so client
      * must pick the one we sent. Verify this */
     if (data[0] != vs->auth) { /* Reject auth */
-       VNC_DEBUG("Reject auth %d\n", (int)data[0]);
+       VNC_DEBUG("Reject auth %d because it didn't match advertized\n", (int)data[0]);
        vnc_write_u32(vs, 1);
        if (vs->minor >= 8) {
            static const char err[] = "Authentication failed";
@@ -1821,7 +1836,7 @@ static int protocol_client_auth(VncState
 #endif /* CONFIG_VNC_SASL */
 
        default: /* Should not be possible, but just in case */
-           VNC_DEBUG("Reject auth %d\n", vs->auth);
+           VNC_DEBUG("Reject auth %d server code bug\n", vs->auth);
            vnc_write_u8(vs, 1);
            if (vs->minor >= 8) {
                static const char err[] = "Authentication failed";

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