[qemu.git] / vnc-tls.c

/*
 * QEMU VNC display driver: TLS helpers
 *
 * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
 * Copyright (C) 2006 Fabrice Bellard
 * Copyright (C) 2009 Red Hat, Inc
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu-x509.h"
#include "vnc.h"
#include "qemu_socket.h"

#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2
/* Very verbose, so only enabled for _VNC_DEBUG >= 2 */
static void vnc_debug_gnutls_log(int level, const char* str) {
    VNC_DEBUG("%d %s", level, str);
}
#endif /* defined(_VNC_DEBUG) && _VNC_DEBUG >= 2 */


#define DH_BITS 1024
static gnutls_dh_params_t dh_params;

static int vnc_tls_initialize(void)
{
    static int tlsinitialized = 0;

    if (tlsinitialized)
        return 1;

    if (gnutls_global_init () < 0)
        return 0;

    /* XXX ought to re-generate diffie-hellmen params periodically */
    if (gnutls_dh_params_init (&dh_params) < 0)
        return 0;
    if (gnutls_dh_params_generate2 (dh_params, DH_BITS) < 0)
        return 0;

#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2
    gnutls_global_set_log_level(10);
    gnutls_global_set_log_function(vnc_debug_gnutls_log);
#endif

    tlsinitialized = 1;

    return 1;
}

static ssize_t vnc_tls_push(gnutls_transport_ptr_t transport,
                            const void *data,
                            size_t len) {
    struct VncState *vs = (struct VncState *)transport;
    int ret;

 retry:
    ret = send(vs->csock, data, len, 0);
    if (ret < 0) {
        if (errno == EINTR)
            goto retry;
        return -1;
    }
    return ret;
}


static ssize_t vnc_tls_pull(gnutls_transport_ptr_t transport,
                            void *data,
                            size_t len) {
    struct VncState *vs = (struct VncState *)transport;
    int ret;

 retry:
    ret = recv(vs->csock, data, len, 0);
    if (ret < 0) {
        if (errno == EINTR)
            goto retry;
        return -1;
    }
    return ret;
}


static gnutls_anon_server_credentials vnc_tls_initialize_anon_cred(void)
{
    gnutls_anon_server_credentials anon_cred;
    int ret;

    if ((ret = gnutls_anon_allocate_server_credentials(&anon_cred)) < 0) {
        VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
        return NULL;
    }

    gnutls_anon_set_server_dh_params(anon_cred, dh_params);

    return anon_cred;
}


static gnutls_certificate_credentials_t vnc_tls_initialize_x509_cred(VncDisplay *vd)
{
    gnutls_certificate_credentials_t x509_cred;
    int ret;

    if (!vd->tls.x509cacert) {
        VNC_DEBUG("No CA x509 certificate specified\n");
        return NULL;
    }
    if (!vd->tls.x509cert) {
        VNC_DEBUG("No server x509 certificate specified\n");
        return NULL;
    }
    if (!vd->tls.x509key) {
        VNC_DEBUG("No server private key specified\n");
        return NULL;
    }

    if ((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0) {
        VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
        return NULL;
    }
    if ((ret = gnutls_certificate_set_x509_trust_file(x509_cred,
                                                      vd->tls.x509cacert,
                                                      GNUTLS_X509_FMT_PEM)) < 0) {
        VNC_DEBUG("Cannot load CA certificate %s\n", gnutls_strerror(ret));
        gnutls_certificate_free_credentials(x509_cred);
        return NULL;
    }

    if ((ret = gnutls_certificate_set_x509_key_file (x509_cred,
                                                     vd->tls.x509cert,
                                                     vd->tls.x509key,
                                                     GNUTLS_X509_FMT_PEM)) < 0) {
        VNC_DEBUG("Cannot load certificate & key %s\n", gnutls_strerror(ret));
        gnutls_certificate_free_credentials(x509_cred);
        return NULL;
    }

    if (vd->tls.x509cacrl) {
        if ((ret = gnutls_certificate_set_x509_crl_file(x509_cred,
                                                        vd->tls.x509cacrl,
                                                        GNUTLS_X509_FMT_PEM)) < 0) {
            VNC_DEBUG("Cannot load CRL %s\n", gnutls_strerror(ret));
            gnutls_certificate_free_credentials(x509_cred);
            return NULL;
        }
    }

    gnutls_certificate_set_dh_params (x509_cred, dh_params);

    return x509_cred;
}


int vnc_tls_validate_certificate(struct VncState *vs)
{
    int ret;
    unsigned int status;
    const gnutls_datum_t *certs;
    unsigned int nCerts, i;
    time_t now;

    VNC_DEBUG("Validating client certificate\n");
    if ((ret = gnutls_certificate_verify_peers2 (vs->tls.session, &status)) < 0) {
        VNC_DEBUG("Verify failed %s\n", gnutls_strerror(ret));
        return -1;
    }

    if ((now = time(NULL)) == ((time_t)-1)) {
        return -1;
    }

    if (status != 0) {
        if (status & GNUTLS_CERT_INVALID)
            VNC_DEBUG("The certificate is not trusted.\n");

        if (status & GNUTLS_CERT_SIGNER_NOT_FOUND)
            VNC_DEBUG("The certificate hasn't got a known issuer.\n");

        if (status & GNUTLS_CERT_REVOKED)
            VNC_DEBUG("The certificate has been revoked.\n");

        if (status & GNUTLS_CERT_INSECURE_ALGORITHM)
            VNC_DEBUG("The certificate uses an insecure algorithm\n");

        return -1;
    } else {
        VNC_DEBUG("Certificate is valid!\n");
    }

    /* Only support x509 for now */
    if (gnutls_certificate_type_get(vs->tls.session) != GNUTLS_CRT_X509)
        return -1;

    if (!(certs = gnutls_certificate_get_peers(vs->tls.session, &nCerts)))
        return -1;

    for (i = 0 ; i < nCerts ; i++) {
        gnutls_x509_crt_t cert;
        VNC_DEBUG ("Checking certificate chain %d\n", i);
        if (gnutls_x509_crt_init (&cert) < 0)
            return -1;

        if (gnutls_x509_crt_import(cert, &certs[i], GNUTLS_X509_FMT_DER) < 0) {
            gnutls_x509_crt_deinit (cert);
            return -1;
        }

        if (gnutls_x509_crt_get_expiration_time (cert) < now) {
            VNC_DEBUG("The certificate has expired\n");
            gnutls_x509_crt_deinit (cert);
            return -1;
        }

        if (gnutls_x509_crt_get_activation_time (cert) > now) {
            VNC_DEBUG("The certificate is not yet activated\n");
            gnutls_x509_crt_deinit (cert);
            return -1;
        }

        if (gnutls_x509_crt_get_activation_time (cert) > now) {
            VNC_DEBUG("The certificate is not yet activated\n");
            gnutls_x509_crt_deinit (cert);
            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;
            }

            if (vs->vd->tls.x509verify) {
                int allow;
                if (!vs->vd->tls.acl) {
                    VNC_DEBUG("no ACL activated, allowing access");
                    gnutls_x509_crt_deinit (cert);
                    continue;
                }

                allow = qemu_acl_party_is_allowed(vs->vd->tls.acl,
                                                  vs->tls.dname);

                VNC_DEBUG("TLS x509 ACL check for %s is %s\n",
                          vs->tls.dname, allow ? "allowed" : "denied");
                if (!allow) {
                    gnutls_x509_crt_deinit (cert);
                    return -1;
                }
            }
        }

        gnutls_x509_crt_deinit (cert);
    }

    return 0;
}


int vnc_tls_client_setup(struct VncState *vs,
                         int needX509Creds) {
    static const int cert_type_priority[] = { GNUTLS_CRT_X509, 0 };
    static const int protocol_priority[]= { GNUTLS_TLS1_1, GNUTLS_TLS1_0, GNUTLS_SSL3, 0 };
    static const int kx_anon[] = {GNUTLS_KX_ANON_DH, 0};
    static const int kx_x509[] = {GNUTLS_KX_DHE_DSS, GNUTLS_KX_RSA, GNUTLS_KX_DHE_RSA, GNUTLS_KX_SRP, 0};

    VNC_DEBUG("Do TLS setup\n");
    if (vnc_tls_initialize() < 0) {
        VNC_DEBUG("Failed to init TLS\n");
        vnc_client_error(vs);
        return -1;
    }
    if (vs->tls.session == NULL) {
        if (gnutls_init(&vs->tls.session, GNUTLS_SERVER) < 0) {
            vnc_client_error(vs);
            return -1;
        }

        if (gnutls_set_default_priority(vs->tls.session) < 0) {
            gnutls_deinit(vs->tls.session);
            vs->tls.session = NULL;
            vnc_client_error(vs);
            return -1;
        }

        if (gnutls_kx_set_priority(vs->tls.session, needX509Creds ? kx_x509 : kx_anon) < 0) {
            gnutls_deinit(vs->tls.session);
            vs->tls.session = NULL;
            vnc_client_error(vs);
            return -1;
        }

        if (gnutls_certificate_type_set_priority(vs->tls.session, cert_type_priority) < 0) {
            gnutls_deinit(vs->tls.session);
            vs->tls.session = NULL;
            vnc_client_error(vs);
            return -1;
        }

        if (gnutls_protocol_set_priority(vs->tls.session, protocol_priority) < 0) {
            gnutls_deinit(vs->tls.session);
            vs->tls.session = NULL;
            vnc_client_error(vs);
            return -1;
        }

        if (needX509Creds) {
            gnutls_certificate_server_credentials x509_cred = vnc_tls_initialize_x509_cred(vs->vd);
            if (!x509_cred) {
                gnutls_deinit(vs->tls.session);
                vs->tls.session = NULL;
                vnc_client_error(vs);
                return -1;
            }
            if (gnutls_credentials_set(vs->tls.session, GNUTLS_CRD_CERTIFICATE, x509_cred) < 0) {
                gnutls_deinit(vs->tls.session);
                vs->tls.session = NULL;
                gnutls_certificate_free_credentials(x509_cred);
                vnc_client_error(vs);
                return -1;
            }
            if (vs->vd->tls.x509verify) {
                VNC_DEBUG("Requesting a client certificate\n");
                gnutls_certificate_server_set_request (vs->tls.session, GNUTLS_CERT_REQUEST);
            }

        } else {
            gnutls_anon_server_credentials anon_cred = vnc_tls_initialize_anon_cred();
            if (!anon_cred) {
                gnutls_deinit(vs->tls.session);
                vs->tls.session = NULL;
                vnc_client_error(vs);
                return -1;
            }
            if (gnutls_credentials_set(vs->tls.session, GNUTLS_CRD_ANON, anon_cred) < 0) {
                gnutls_deinit(vs->tls.session);
                vs->tls.session = NULL;
                gnutls_anon_free_server_credentials(anon_cred);
                vnc_client_error(vs);
                return -1;
            }
        }

        gnutls_transport_set_ptr(vs->tls.session, (gnutls_transport_ptr_t)vs);
        gnutls_transport_set_push_function(vs->tls.session, vnc_tls_push);
        gnutls_transport_set_pull_function(vs->tls.session, vnc_tls_pull);
    }
    return 0;
}


void vnc_tls_client_cleanup(struct VncState *vs)
{
    if (vs->tls.session) {
        gnutls_deinit(vs->tls.session);
        vs->tls.session = NULL;
    }
    vs->tls.wiremode = VNC_WIREMODE_CLEAR;
    free(vs->tls.dname);
}


static int vnc_set_x509_credential(VncDisplay *vd,
                                   const char *certdir,
                                   const char *filename,
                                   char **cred,
                                   int ignoreMissing)
{
    struct stat sb;

    if (*cred) {
        qemu_free(*cred);
        *cred = NULL;
    }

    *cred = qemu_malloc(strlen(certdir) + strlen(filename) + 2);

    strcpy(*cred, certdir);
    strcat(*cred, "/");
    strcat(*cred, filename);

    VNC_DEBUG("Check %s\n", *cred);
    if (stat(*cred, &sb) < 0) {
        qemu_free(*cred);
        *cred = NULL;
        if (ignoreMissing && errno == ENOENT)
            return 0;
        return -1;
    }

    return 0;
}


int vnc_tls_set_x509_creds_dir(VncDisplay *vd,
                               const char *certdir)
{
    if (vnc_set_x509_credential(vd, certdir, X509_CA_CERT_FILE, &vd->tls.x509cacert, 0) < 0)
        goto cleanup;
    if (vnc_set_x509_credential(vd, certdir, X509_CA_CRL_FILE, &vd->tls.x509cacrl, 1) < 0)
        goto cleanup;
    if (vnc_set_x509_credential(vd, certdir, X509_SERVER_CERT_FILE, &vd->tls.x509cert, 0) < 0)
        goto cleanup;
    if (vnc_set_x509_credential(vd, certdir, X509_SERVER_KEY_FILE, &vd->tls.x509key, 0) < 0)
        goto cleanup;

    return 0;

 cleanup:
    qemu_free(vd->tls.x509cacert);
    qemu_free(vd->tls.x509cacrl);
    qemu_free(vd->tls.x509cert);
    qemu_free(vd->tls.x509key);
    vd->tls.x509cacert = vd->tls.x509cacrl = vd->tls.x509cert = vd->tls.x509key = NULL;
    return -1;
}
Commit	Line	Data
274b6fcc AL	1	/*
	2	* QEMU VNC display driver: TLS helpers
	3	*
	4	* Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
	5	* Copyright (C) 2006 Fabrice Bellard
	6	* Copyright (C) 2009 Red Hat, Inc
	7	*
	8	* Permission is hereby granted, free of charge, to any person obtaining a copy
	9	* of this software and associated documentation files (the "Software"), to deal
	10	* in the Software without restriction, including without limitation the rights
	11	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	12	* copies of the Software, and to permit persons to whom the Software is
	13	* furnished to do so, subject to the following conditions:
	14	*
	15	* The above copyright notice and this permission notice shall be included in
	16	* all copies or substantial portions of the Software.
	17	*
	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	20	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	21	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	22	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	23	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	24	* THE SOFTWARE.
	25	*/
	26
de7890db	27	#include "qemu-x509.h"
274b6fcc AL	28	#include "vnc.h"
	29	#include "qemu_socket.h"
	30
	31	#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2
	32	/* Very verbose, so only enabled for _VNC_DEBUG >= 2 */
	33	static void vnc_debug_gnutls_log(int level, const char* str) {
	34	VNC_DEBUG("%d %s", level, str);
	35	}
	36	#endif /* defined(_VNC_DEBUG) && _VNC_DEBUG >= 2 */
	37
	38
	39	#define DH_BITS 1024
	40	static gnutls_dh_params_t dh_params;
	41
	42	static int vnc_tls_initialize(void)
	43	{
	44	static int tlsinitialized = 0;
	45
	46	if (tlsinitialized)
	47	return 1;
	48
	49	if (gnutls_global_init () < 0)
	50	return 0;
	51
	52	/* XXX ought to re-generate diffie-hellmen params periodically */
	53	if (gnutls_dh_params_init (&dh_params) < 0)
	54	return 0;
	55	if (gnutls_dh_params_generate2 (dh_params, DH_BITS) < 0)
	56	return 0;
	57
	58	#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2
	59	gnutls_global_set_log_level(10);
	60	gnutls_global_set_log_function(vnc_debug_gnutls_log);
	61	#endif
	62
	63	tlsinitialized = 1;
	64
	65	return 1;
	66	}
	67
	68	static ssize_t vnc_tls_push(gnutls_transport_ptr_t transport,
	69	const void *data,
	70	size_t len) {
	71	struct VncState vs = (struct VncState )transport;
	72	int ret;
	73
	74	retry:
	75	ret = send(vs->csock, data, len, 0);
	76	if (ret < 0) {
	77	if (errno == EINTR)
	78	goto retry;
	79	return -1;
	80	}
	81	return ret;
	82	}
	83
	84
	85	static ssize_t vnc_tls_pull(gnutls_transport_ptr_t transport,
	86	void *data,
	87	size_t len) {
	88	struct VncState vs = (struct VncState )transport;
	89	int ret;
	90
	91	retry:
92	ret = recv(vs->csock, data, len, 0);
93	if (ret < 0) {
94	if (errno == EINTR)
95	goto retry;
96	return -1;
97	}
98	return ret;
99	}
100
101
102	static gnutls_anon_server_credentials vnc_tls_initialize_anon_cred(void)
103	{
104	gnutls_anon_server_credentials anon_cred;
105	int ret;
106
107	if ((ret = gnutls_anon_allocate_server_credentials(&anon_cred)) < 0) {
108	VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
109	return NULL;
110	}
111
112	gnutls_anon_set_server_dh_params(anon_cred, dh_params);
113
114	return anon_cred;
115	}
116
117
118	static gnutls_certificate_credentials_t vnc_tls_initialize_x509_cred(VncDisplay *vd)
119	{
120	gnutls_certificate_credentials_t x509_cred;
121	int ret;
122
123	if (!vd->tls.x509cacert) {
124	VNC_DEBUG("No CA x509 certificate specified\n");
125	return NULL;
126	}
127	if (!vd->tls.x509cert) {
128	VNC_DEBUG("No server x509 certificate specified\n");
129	return NULL;
130	}
131	if (!vd->tls.x509key) {
132	VNC_DEBUG("No server private key specified\n");
133	return NULL;
134	}
135
136	if ((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0) {
137	VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
138	return NULL;
139	}
140	if ((ret = gnutls_certificate_set_x509_trust_file(x509_cred,
141	vd->tls.x509cacert,
142	GNUTLS_X509_FMT_PEM)) < 0) {
143	VNC_DEBUG("Cannot load CA certificate %s\n", gnutls_strerror(ret));
144	gnutls_certificate_free_credentials(x509_cred);
145	return NULL;
146	}
147
148	if ((ret = gnutls_certificate_set_x509_key_file (x509_cred,
149	vd->tls.x509cert,
150	vd->tls.x509key,
151	GNUTLS_X509_FMT_PEM)) < 0) {
152	VNC_DEBUG("Cannot load certificate & key %s\n", gnutls_strerror(ret));
153	gnutls_certificate_free_credentials(x509_cred);
154	return NULL;
155	}
156
157	if (vd->tls.x509cacrl) {
158	if ((ret = gnutls_certificate_set_x509_crl_file(x509_cred,
159	vd->tls.x509cacrl,
160	GNUTLS_X509_FMT_PEM)) < 0) {
161	VNC_DEBUG("Cannot load CRL %s\n", gnutls_strerror(ret));
162	gnutls_certificate_free_credentials(x509_cred);
163	return NULL;
164	}
165	}
166
167	gnutls_certificate_set_dh_params (x509_cred, dh_params);
168
169	return x509_cred;
170	}
171
172
173	int vnc_tls_validate_certificate(struct VncState *vs)
174	{
175	int ret;
176	unsigned int status;
177	const gnutls_datum_t *certs;
178	unsigned int nCerts, i;
179	time_t now;
180
181	VNC_DEBUG("Validating client certificate\n");
182	if ((ret = gnutls_certificate_verify_peers2 (vs->tls.session, &status)) < 0) {
183	VNC_DEBUG("Verify failed %s\n", gnutls_strerror(ret));
184	return -1;
185	}
186
187	if ((now = time(NULL)) == ((time_t)-1)) {
188	return -1;
189	}
190
191	if (status != 0) {
192	if (status & GNUTLS_CERT_INVALID)
193	VNC_DEBUG("The certificate is not trusted.\n");
194
195	if (status & GNUTLS_CERT_SIGNER_NOT_FOUND)
196	VNC_DEBUG("The certificate hasn't got a known issuer.\n");
197
198	if (status & GNUTLS_CERT_REVOKED)
199	VNC_DEBUG("The certificate has been revoked.\n");
200
201	if (status & GNUTLS_CERT_INSECURE_ALGORITHM)
202	VNC_DEBUG("The certificate uses an insecure algorithm\n");
203
204	return -1;
205	} else {
206	VNC_DEBUG("Certificate is valid!\n");
207	}
208
209	/* Only support x509 for now */
210	if (gnutls_certificate_type_get(vs->tls.session) != GNUTLS_CRT_X509)
211	return -1;
212
213	if (!(certs = gnutls_certificate_get_peers(vs->tls.session, &nCerts)))
214	return -1;
215
216	for (i = 0 ; i < nCerts ; i++) {
217	gnutls_x509_crt_t cert;
218	VNC_DEBUG ("Checking certificate chain %d\n", i);
219	if (gnutls_x509_crt_init (&cert) < 0)
220	return -1;
221
222	if (gnutls_x509_crt_import(cert, &certs[i], GNUTLS_X509_FMT_DER) < 0) {
223	gnutls_x509_crt_deinit (cert);
224	return -1;
225	}
226
227	if (gnutls_x509_crt_get_expiration_time (cert) < now) {
228	VNC_DEBUG("The certificate has expired\n");
229	gnutls_x509_crt_deinit (cert);
230	return -1;
231	}
232
233	if (gnutls_x509_crt_get_activation_time (cert) > now) {
234	VNC_DEBUG("The certificate is not yet activated\n");
235	gnutls_x509_crt_deinit (cert);
236	return -1;
237	}
238
239	if (gnutls_x509_crt_get_activation_time (cert) > now) {
240	VNC_DEBUG("The certificate is not yet activated\n");
241	gnutls_x509_crt_deinit (cert);
242	return -1;
243	}
244
245	if (i == 0) {
246	size_t dnameSize = 1024;
247	vs->tls.dname = qemu_malloc(dnameSize);
248	requery:
249	if ((ret = gnutls_x509_crt_get_dn (cert, vs->tls.dname, &dnameSize)) != 0) {
250	if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER) {
251	vs->tls.dname = qemu_realloc(vs->tls.dname, dnameSize);
252	goto requery;
253	}
254	gnutls_x509_crt_deinit (cert);
255	VNC_DEBUG("Cannot get client distinguished name: %s",
256	gnutls_strerror (ret));
257	return -1;
258	}
259
260	if (vs->vd->tls.x509verify) {
261	int allow;
262	if (!vs->vd->tls.acl) {
263	VNC_DEBUG("no ACL activated, allowing access");
264	gnutls_x509_crt_deinit (cert);
265	continue;
266	}
267
268	allow = qemu_acl_party_is_allowed(vs->vd->tls.acl,
269	vs->tls.dname);
270
271	VNC_DEBUG("TLS x509 ACL check for %s is %s\n",
272	vs->tls.dname, allow ? "allowed" : "denied");
273	if (!allow) {
274	gnutls_x509_crt_deinit (cert);
275	return -1;
276	}
277	}
278	}
279
280	gnutls_x509_crt_deinit (cert);
281	}
282
283	return 0;
284	}
285
286
287	int vnc_tls_client_setup(struct VncState *vs,
288	int needX509Creds) {
289	static const int cert_type_priority[] = { GNUTLS_CRT_X509, 0 };
290	static const int protocol_priority[]= { GNUTLS_TLS1_1, GNUTLS_TLS1_0, GNUTLS_SSL3, 0 };
291	static const int kx_anon[] = {GNUTLS_KX_ANON_DH, 0};
292	static const int kx_x509[] = {GNUTLS_KX_DHE_DSS, GNUTLS_KX_RSA, GNUTLS_KX_DHE_RSA, GNUTLS_KX_SRP, 0};
293
294	VNC_DEBUG("Do TLS setup\n");
295	if (vnc_tls_initialize() < 0) {
296	VNC_DEBUG("Failed to init TLS\n");
297	vnc_client_error(vs);
298	return -1;
299	}
300	if (vs->tls.session == NULL) {
301	if (gnutls_init(&vs->tls.session, GNUTLS_SERVER) < 0) {
302	vnc_client_error(vs);
303	return -1;
304	}
305
306	if (gnutls_set_default_priority(vs->tls.session) < 0) {
307	gnutls_deinit(vs->tls.session);
308	vs->tls.session = NULL;
309	vnc_client_error(vs);
310	return -1;
311	}
312
313	if (gnutls_kx_set_priority(vs->tls.session, needX509Creds ? kx_x509 : kx_anon) < 0) {
314	gnutls_deinit(vs->tls.session);
315	vs->tls.session = NULL;
316	vnc_client_error(vs);
317	return -1;
318	}
319
320	if (gnutls_certificate_type_set_priority(vs->tls.session, cert_type_priority) < 0) {
321	gnutls_deinit(vs->tls.session);
322	vs->tls.session = NULL;
323	vnc_client_error(vs);
324	return -1;
325	}
326
327	if (gnutls_protocol_set_priority(vs->tls.session, protocol_priority) < 0) {
328	gnutls_deinit(vs->tls.session);
329	vs->tls.session = NULL;
330	vnc_client_error(vs);
331	return -1;
332	}
333
334	if (needX509Creds) {
335	gnutls_certificate_server_credentials x509_cred = vnc_tls_initialize_x509_cred(vs->vd);
336	if (!x509_cred) {
337	gnutls_deinit(vs->tls.session);
338	vs->tls.session = NULL;
339	vnc_client_error(vs);
340	return -1;
341	}
342	if (gnutls_credentials_set(vs->tls.session, GNUTLS_CRD_CERTIFICATE, x509_cred) < 0) {
343	gnutls_deinit(vs->tls.session);
344	vs->tls.session = NULL;
345	gnutls_certificate_free_credentials(x509_cred);
346	vnc_client_error(vs);
347	return -1;
348	}
349	if (vs->vd->tls.x509verify) {
350	VNC_DEBUG("Requesting a client certificate\n");
351	gnutls_certificate_server_set_request (vs->tls.session, GNUTLS_CERT_REQUEST);
352	}
353
354	} else {
355	gnutls_anon_server_credentials anon_cred = vnc_tls_initialize_anon_cred();
356	if (!anon_cred) {
357	gnutls_deinit(vs->tls.session);
358	vs->tls.session = NULL;
359	vnc_client_error(vs);
360	return -1;
361	}
362	if (gnutls_credentials_set(vs->tls.session, GNUTLS_CRD_ANON, anon_cred) < 0) {
363	gnutls_deinit(vs->tls.session);
364	vs->tls.session = NULL;
365	gnutls_anon_free_server_credentials(anon_cred);
366	vnc_client_error(vs);
367	return -1;
368	}
369	}
370
371	gnutls_transport_set_ptr(vs->tls.session, (gnutls_transport_ptr_t)vs);
372	gnutls_transport_set_push_function(vs->tls.session, vnc_tls_push);
373	gnutls_transport_set_pull_function(vs->tls.session, vnc_tls_pull);
374	}
375	return 0;
376	}
377
378
379	void vnc_tls_client_cleanup(struct VncState *vs)
380	{
381	if (vs->tls.session) {
382	gnutls_deinit(vs->tls.session);
383	vs->tls.session = NULL;
384	}
385	vs->tls.wiremode = VNC_WIREMODE_CLEAR;
386	free(vs->tls.dname);
387	}
388
389
390
391	static int vnc_set_x509_credential(VncDisplay *vd,
392	const char *certdir,
393	const char *filename,
394	char **cred,
395	int ignoreMissing)
396	{
397	struct stat sb;
398
399	if (*cred) {
400	qemu_free(*cred);
401	*cred = NULL;
402	}
403
404	*cred = qemu_malloc(strlen(certdir) + strlen(filename) + 2);
405
406	strcpy(*cred, certdir);
407	strcat(*cred, "/");
408	strcat(*cred, filename);
409
410	VNC_DEBUG("Check %s\n", *cred);
411	if (stat(*cred, &sb) < 0) {
412	qemu_free(*cred);
413	*cred = NULL;
414	if (ignoreMissing && errno == ENOENT)
415	return 0;
416	return -1;
417	}
418
419	return 0;
420	}
421
422
274b6fcc AL	423	int vnc_tls_set_x509_creds_dir(VncDisplay *vd,
	424	const char *certdir)
	425	{
	426	if (vnc_set_x509_credential(vd, certdir, X509_CA_CERT_FILE, &vd->tls.x509cacert, 0) < 0)
	427	goto cleanup;
	428	if (vnc_set_x509_credential(vd, certdir, X509_CA_CRL_FILE, &vd->tls.x509cacrl, 1) < 0)
	429	goto cleanup;
	430	if (vnc_set_x509_credential(vd, certdir, X509_SERVER_CERT_FILE, &vd->tls.x509cert, 0) < 0)
	431	goto cleanup;
	432	if (vnc_set_x509_credential(vd, certdir, X509_SERVER_KEY_FILE, &vd->tls.x509key, 0) < 0)
	433	goto cleanup;
	434
	435	return 0;
	436
	437	cleanup:
	438	qemu_free(vd->tls.x509cacert);
	439	qemu_free(vd->tls.x509cacrl);
	440	qemu_free(vd->tls.x509cert);
	441	qemu_free(vd->tls.x509key);
	442	vd->tls.x509cacert = vd->tls.x509cacrl = vd->tls.x509cert = vd->tls.x509key = NULL;
	443	return -1;
	444	}
	445