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 int ret; 71 72 if ((ret = gnutls_handshake(vs->tls.session)) < 0) { 73 if (!gnutls_error_is_fatal(ret)) { 74 VNC_DEBUG("Handshake interrupted (blocking)\n"); 75 if (!gnutls_record_get_direction(vs->tls.session)) 76 qemu_set_fd_handler(vs->csock, vnc_tls_handshake_io, NULL, vs); 77 else 78 qemu_set_fd_handler(vs->csock, NULL, vnc_tls_handshake_io, vs); 79 return 0; 80 } 81 VNC_DEBUG("Handshake failed %s\n", gnutls_strerror(ret)); 82 vnc_client_error(vs); 83 return -1; 84 } 85 86 if (vs->vd->tls.x509verify) { 87 if (vnc_tls_validate_certificate(vs) < 0) { 88 VNC_DEBUG("Client verification failed\n"); 89 vnc_client_error(vs); 90 return -1; 91 } else { 92 VNC_DEBUG("Client verification passed\n"); 93 } 94 } 95 96 VNC_DEBUG("Handshake done, switching to TLS data mode\n"); 97 qemu_set_fd_handler2(vs->csock, NULL, vnc_client_read, vnc_client_write, vs); 98 99 start_auth_vencrypt_subauth(vs); 100 101 return 0; 102 } 103 104 static void vnc_tls_handshake_io(void *opaque) 105 { 106 VncState *vs = (VncState *)opaque; 107 108 VNC_DEBUG("Handshake IO continue\n"); 109 vnc_start_vencrypt_handshake(vs); 110 } 111 112 113 114 #define NEED_X509_AUTH(vs) \ 115 ((vs)->subauth == VNC_AUTH_VENCRYPT_X509NONE || \ 116 (vs)->subauth == VNC_AUTH_VENCRYPT_X509VNC || \ 117 (vs)->subauth == VNC_AUTH_VENCRYPT_X509PLAIN || \ 118 (vs)->subauth == VNC_AUTH_VENCRYPT_X509SASL) 119 120 121 static int protocol_client_vencrypt_auth(VncState *vs, uint8_t *data, size_t len) 122 { 123 int auth = read_u32(data, 0); 124 125 if (auth != vs->subauth) { 126 VNC_DEBUG("Rejecting auth %d\n", auth); 127 vnc_write_u8(vs, 0); /* Reject auth */ 128 vnc_flush(vs); 129 vnc_client_error(vs); 130 } else { 131 VNC_DEBUG("Accepting auth %d, setting up TLS for handshake\n", auth); 132 vnc_write_u8(vs, 1); /* Accept auth */ 133 vnc_flush(vs); 134 135 if (vnc_tls_client_setup(vs, NEED_X509_AUTH(vs)) < 0) { 136 VNC_DEBUG("Failed to setup TLS\n"); 137 return 0; 138 } 139 140 VNC_DEBUG("Start TLS VeNCrypt handshake process\n"); 141 if (vnc_start_vencrypt_handshake(vs) < 0) { 142 VNC_DEBUG("Failed to start TLS handshake\n"); 143 return 0; 144 } 145 } 146 return 0; 147 } 148 149 static int protocol_client_vencrypt_init(VncState *vs, uint8_t *data, size_t len) 150 { 151 if (data[0] != 0 || 152 data[1] != 2) { 153 VNC_DEBUG("Unsupported VeNCrypt protocol %d.%d\n", (int)data[0], (int)data[1]); 154 vnc_write_u8(vs, 1); /* Reject version */ 155 vnc_flush(vs); 156 vnc_client_error(vs); 157 } else { 158 VNC_DEBUG("Sending allowed auth %d\n", vs->subauth); 159 vnc_write_u8(vs, 0); /* Accept version */ 160 vnc_write_u8(vs, 1); /* Number of sub-auths */ 161 vnc_write_u32(vs, vs->subauth); /* The supported auth */ 162 vnc_flush(vs); 163 vnc_read_when(vs, protocol_client_vencrypt_auth, 4); 164 } 165 return 0; 166 } 167 168 169 void start_auth_vencrypt(VncState *vs) 170 { 171 /* Send VeNCrypt version 0.2 */ 172 vnc_write_u8(vs, 0); 173 vnc_write_u8(vs, 2); 174 175 vnc_read_when(vs, protocol_client_vencrypt_init, 2); 176 } 177 178