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 } 187 188