ui/vnc-auth-vencrypt.c

   1 /*
   2  * QEMU VNC display driver: VeNCrypt authentication setup
   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
  27 #include "vnc.h"
  28 #include "qemu/main-loop.h"
  29
  30 static void start_auth_vencrypt_subauth(VncState *vs)
  31 {
  32     switch (vs->subauth) {
  33     case VNC_AUTH_VENCRYPT_TLSNONE:
  34     case VNC_AUTH_VENCRYPT_X509NONE:
  35        VNC_DEBUG("Accept TLS auth none\n");
  36        vnc_write_u32(vs, 0); /* Accept auth completion */
  37        start_client_init(vs);
  38        break;
  39
  40     case VNC_AUTH_VENCRYPT_TLSVNC:
  41     case VNC_AUTH_VENCRYPT_X509VNC:
  42        VNC_DEBUG("Start TLS auth VNC\n");
  43        start_auth_vnc(vs);
  44        break;
  45
  46 #ifdef CONFIG_VNC_SASL
  47     case VNC_AUTH_VENCRYPT_TLSSASL:
  48     case VNC_AUTH_VENCRYPT_X509SASL:
  49       VNC_DEBUG("Start TLS auth SASL\n");
  50       start_auth_sasl(vs);
  51       break;
  52 #endif /* CONFIG_VNC_SASL */
  53
  54     default: /* Should not be possible, but just in case */
  55        VNC_DEBUG("Reject subauth %d server bug\n", vs->auth);
  56        vnc_write_u8(vs, 1);
  57        if (vs->minor >= 8) {
  58            static const char err[] = "Unsupported authentication type";
  59            vnc_write_u32(vs, sizeof(err));
  60            vnc_write(vs, err, sizeof(err));
  61        }
  62        vnc_client_error(vs);
  63     }
  64 }
  65
  66 static void vnc_tls_handshake_io(void *opaque);
  67
  68 static int vnc_start_vencrypt_handshake(VncState *vs)
  69 {
  70     Error *err = NULL;
  71
  72     if (qcrypto_tls_session_handshake(vs->tls, &err) < 0) {
  73         goto error;
  74     }
  75
  76     switch (qcrypto_tls_session_get_handshake_status(vs->tls)) {
  77     case QCRYPTO_TLS_HANDSHAKE_COMPLETE:
  78         VNC_DEBUG("Handshake done, checking credentials\n");
  79         if (qcrypto_tls_session_check_credentials(vs->tls, &err) < 0) {
  80             goto error;
  81         }
  82         VNC_DEBUG("Client verification passed, starting TLS I/O\n");
  83         qemu_set_fd_handler(vs->csock, vnc_client_read, vnc_client_write, vs);
  84
  85         start_auth_vencrypt_subauth(vs);
  86         break;
  87
  88     case QCRYPTO_TLS_HANDSHAKE_RECVING:
  89         VNC_DEBUG("Handshake interrupted (blocking read)\n");
  90         qemu_set_fd_handler(vs->csock, vnc_tls_handshake_io, NULL, vs);
  91         break;
  92
  93     case QCRYPTO_TLS_HANDSHAKE_SENDING:
  94         VNC_DEBUG("Handshake interrupted (blocking write)\n");
  95         qemu_set_fd_handler(vs->csock, NULL, vnc_tls_handshake_io, vs);
  96         break;
  97     }
  98
  99     return 0;
 100
 101  error:
 102     VNC_DEBUG("Handshake failed %s\n", error_get_pretty(err));
 103     error_free(err);
 104     vnc_client_error(vs);
 105     return -1;
 106 }
 107
 108 static void vnc_tls_handshake_io(void *opaque)
 109 {
 110     VncState *vs = (VncState *)opaque;
 111
 112     VNC_DEBUG("Handshake IO continue\n");
 113     vnc_start_vencrypt_handshake(vs);
 114 }
 115
 116
 117 static int protocol_client_vencrypt_auth(VncState *vs, uint8_t *data, size_t len)
 118 {
 119     int auth = read_u32(data, 0);
 120
 121     if (auth != vs->subauth) {
 122         VNC_DEBUG("Rejecting auth %d\n", auth);
 123         vnc_write_u8(vs, 0); /* Reject auth */
 124         vnc_flush(vs);
 125         vnc_client_error(vs);
 126     } else {
 127         Error *err = NULL;
 128         VNC_DEBUG("Accepting auth %d, setting up TLS for handshake\n", auth);
 129         vnc_write_u8(vs, 1); /* Accept auth */
 130         vnc_flush(vs);
 131
 132         vs->tls = qcrypto_tls_session_new(vs->vd->tlscreds,
 133                                           NULL,
 134                                           vs->vd->tlsaclname,
 135                                           QCRYPTO_TLS_CREDS_ENDPOINT_SERVER,
 136                                           &err);
 137         if (!vs->tls) {
 138             VNC_DEBUG("Failed to setup TLS %s\n",
 139                       error_get_pretty(err));
 140             error_free(err);
 141             vnc_client_error(vs);
 142             return 0;
 143         }
 144
 145         qcrypto_tls_session_set_callbacks(vs->tls,
 146                                           vnc_tls_push,
 147                                           vnc_tls_pull,
 148                                           vs);
 149
 150         VNC_DEBUG("Start TLS VeNCrypt handshake process\n");
 151         if (vnc_start_vencrypt_handshake(vs) < 0) {
 152             VNC_DEBUG("Failed to start TLS handshake\n");
 153             return 0;
 154         }
 155     }
 156     return 0;
 157 }
 158
 159 static int protocol_client_vencrypt_init(VncState *vs, uint8_t *data, size_t len)
 160 {
 161     if (data[0] != 0 ||
 162         data[1] != 2) {
 163         VNC_DEBUG("Unsupported VeNCrypt protocol %d.%d\n", (int)data[0], (int)data[1]);
 164         vnc_write_u8(vs, 1); /* Reject version */
 165         vnc_flush(vs);
 166         vnc_client_error(vs);
 167     } else {
 168         VNC_DEBUG("Sending allowed auth %d\n", vs->subauth);
 169         vnc_write_u8(vs, 0); /* Accept version */
 170         vnc_write_u8(vs, 1); /* Number of sub-auths */
 171         vnc_write_u32(vs, vs->subauth); /* The supported auth */
 172         vnc_flush(vs);
 173         vnc_read_when(vs, protocol_client_vencrypt_auth, 4);
 174     }
 175     return 0;
 176 }
 177
 178
 179 void start_auth_vencrypt(VncState *vs)
 180 {
 181     /* Send VeNCrypt version 0.2 */
 182     vnc_write_u8(vs, 0);
 183     vnc_write_u8(vs, 2);
 184
 185     vnc_read_when(vs, protocol_client_vencrypt_init, 2);
 186 }
 187