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 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(struct VncState *vs) { 69 int ret; 70 71 if ((ret = gnutls_handshake(vs->tls.session)) < 0) { 72 if (!gnutls_error_is_fatal(ret)) { 73 VNC_DEBUG("Handshake interrupted (blocking)\n"); 74 if (!gnutls_record_get_direction(vs->tls.session)) 75 qemu_set_fd_handler(vs->csock, vnc_tls_handshake_io, NULL, vs); 76 else 77 qemu_set_fd_handler(vs->csock, NULL, vnc_tls_handshake_io, vs); 78 return 0; 79 } 80 VNC_DEBUG("Handshake failed %s\n", gnutls_strerror(ret)); 81 vnc_client_error(vs); 82 return -1; 83 } 84 85 if (vs->vd->tls.x509verify) { 86 if (vnc_tls_validate_certificate(vs) < 0) { 87 VNC_DEBUG("Client verification failed\n"); 88 vnc_client_error(vs); 89 return -1; 90 } else { 91 VNC_DEBUG("Client verification passed\n"); 92 } 93 } 94 95 VNC_DEBUG("Handshake done, switching to TLS data mode\n"); 96 vs->tls.wiremode = VNC_WIREMODE_TLS; 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 struct VncState *vs = (struct VncState *)opaque; 106 107 VNC_DEBUG("Handshake IO continue\n"); 108 vnc_start_vencrypt_handshake(vs); 109 } 110 111 112 113 #define NEED_X509_AUTH(vs) \ 114 ((vs)->subauth == VNC_AUTH_VENCRYPT_X509NONE || \ 115 (vs)->subauth == VNC_AUTH_VENCRYPT_X509VNC || \ 116 (vs)->subauth == VNC_AUTH_VENCRYPT_X509PLAIN || \ 117 (vs)->subauth == VNC_AUTH_VENCRYPT_X509SASL) 118 119 120 static int protocol_client_vencrypt_auth(VncState *vs, uint8_t *data, size_t len) 121 { 122 int auth = read_u32(data, 0); 123 124 if (auth != vs->subauth) { 125 VNC_DEBUG("Rejecting auth %d\n", auth); 126 vnc_write_u8(vs, 0); /* Reject auth */ 127 vnc_flush(vs); 128 vnc_client_error(vs); 129 } else { 130 VNC_DEBUG("Accepting auth %d, setting up TLS for handshake\n", auth); 131 vnc_write_u8(vs, 1); /* Accept auth */ 132 vnc_flush(vs); 133 134 if (vnc_tls_client_setup(vs, NEED_X509_AUTH(vs)) < 0) { 135 VNC_DEBUG("Failed to setup TLS\n"); 136 return 0; 137 } 138 139 VNC_DEBUG("Start TLS VeNCrypt handshake process\n"); 140 if (vnc_start_vencrypt_handshake(vs) < 0) { 141 VNC_DEBUG("Failed to start TLS handshake\n"); 142 return 0; 143 } 144 } 145 return 0; 146 } 147 148 static int protocol_client_vencrypt_init(VncState *vs, uint8_t *data, size_t len) 149 { 150 if (data[0] != 0 || 151 data[1] != 2) { 152 VNC_DEBUG("Unsupported VeNCrypt protocol %d.%d\n", (int)data[0], (int)data[1]); 153 vnc_write_u8(vs, 1); /* Reject version */ 154 vnc_flush(vs); 155 vnc_client_error(vs); 156 } else { 157 VNC_DEBUG("Sending allowed auth %d\n", vs->subauth); 158 vnc_write_u8(vs, 0); /* Accept version */ 159 vnc_write_u8(vs, 1); /* Number of sub-auths */ 160 vnc_write_u32(vs, vs->subauth); /* The supported auth */ 161 vnc_flush(vs); 162 vnc_read_when(vs, protocol_client_vencrypt_auth, 4); 163 } 164 return 0; 165 } 166 167 168 void start_auth_vencrypt(VncState *vs) 169 { 170 /* Send VeNCrypt version 0.2 */ 171 vnc_write_u8(vs, 0); 172 vnc_write_u8(vs, 2); 173 174 vnc_read_when(vs, protocol_client_vencrypt_init, 2); 175 } 176 177