Annotation of qemu/vnc-auth-vencrypt.c, revision 1.1.1.1

1.1       root        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->vd->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:       return start_auth_sasl(vs);
                     51: #endif /* CONFIG_VNC_SASL */
                     52: 
                     53:     default: /* Should not be possible, but just in case */
                     54:        VNC_DEBUG("Reject subauth %d server bug\n", vs->vd->auth);
                     55:        vnc_write_u8(vs, 1);
                     56:        if (vs->minor >= 8) {
                     57:            static const char err[] = "Unsupported authentication type";
                     58:            vnc_write_u32(vs, sizeof(err));
                     59:            vnc_write(vs, err, sizeof(err));
                     60:        }
                     61:        vnc_client_error(vs);
                     62:     }
                     63: }
                     64: 
                     65: static void vnc_tls_handshake_io(void *opaque);
                     66: 
                     67: static int vnc_start_vencrypt_handshake(struct VncState *vs) {
                     68:     int ret;
                     69: 
                     70:     if ((ret = gnutls_handshake(vs->tls.session)) < 0) {
                     71:        if (!gnutls_error_is_fatal(ret)) {
                     72:            VNC_DEBUG("Handshake interrupted (blocking)\n");
                     73:            if (!gnutls_record_get_direction(vs->tls.session))
                     74:                qemu_set_fd_handler(vs->csock, vnc_tls_handshake_io, NULL, vs);
                     75:            else
                     76:                qemu_set_fd_handler(vs->csock, NULL, vnc_tls_handshake_io, vs);
                     77:            return 0;
                     78:        }
                     79:        VNC_DEBUG("Handshake failed %s\n", gnutls_strerror(ret));
                     80:        vnc_client_error(vs);
                     81:        return -1;
                     82:     }
                     83: 
                     84:     if (vs->vd->tls.x509verify) {
                     85:         if (vnc_tls_validate_certificate(vs) < 0) {
                     86:             VNC_DEBUG("Client verification failed\n");
                     87:             vnc_client_error(vs);
                     88:             return -1;
                     89:         } else {
                     90:             VNC_DEBUG("Client verification passed\n");
                     91:         }
                     92:     }
                     93: 
                     94:     VNC_DEBUG("Handshake done, switching to TLS data mode\n");
                     95:     vs->tls.wiremode = VNC_WIREMODE_TLS;
                     96:     qemu_set_fd_handler2(vs->csock, NULL, vnc_client_read, vnc_client_write, vs);
                     97: 
                     98:     start_auth_vencrypt_subauth(vs);
                     99: 
                    100:     return 0;
                    101: }
                    102: 
                    103: static void vnc_tls_handshake_io(void *opaque) {
                    104:     struct VncState *vs = (struct VncState *)opaque;
                    105: 
                    106:     VNC_DEBUG("Handshake IO continue\n");
                    107:     vnc_start_vencrypt_handshake(vs);
                    108: }
                    109: 
                    110: 
                    111: 
                    112: #define NEED_X509_AUTH(vs)                              \
                    113:     ((vs)->vd->subauth == VNC_AUTH_VENCRYPT_X509NONE ||   \
                    114:      (vs)->vd->subauth == VNC_AUTH_VENCRYPT_X509VNC ||    \
                    115:      (vs)->vd->subauth == VNC_AUTH_VENCRYPT_X509PLAIN ||  \
                    116:      (vs)->vd->subauth == VNC_AUTH_VENCRYPT_X509SASL)
                    117: 
                    118: 
                    119: static int protocol_client_vencrypt_auth(VncState *vs, uint8_t *data, size_t len)
                    120: {
                    121:     int auth = read_u32(data, 0);
                    122: 
                    123:     if (auth != vs->vd->subauth) {
                    124:         VNC_DEBUG("Rejecting auth %d\n", auth);
                    125:         vnc_write_u8(vs, 0); /* Reject auth */
                    126:         vnc_flush(vs);
                    127:         vnc_client_error(vs);
                    128:     } else {
                    129:         VNC_DEBUG("Accepting auth %d, setting up TLS for handshake\n", auth);
                    130:         vnc_write_u8(vs, 1); /* Accept auth */
                    131:         vnc_flush(vs);
                    132: 
                    133:         if (vnc_tls_client_setup(vs, NEED_X509_AUTH(vs)) < 0) {
                    134:             VNC_DEBUG("Failed to setup TLS\n");
                    135:             return 0;
                    136:         }
                    137: 
                    138:         VNC_DEBUG("Start TLS VeNCrypt handshake process\n");
                    139:         if (vnc_start_vencrypt_handshake(vs) < 0) {
                    140:             VNC_DEBUG("Failed to start TLS handshake\n");
                    141:             return 0;
                    142:         }
                    143:     }
                    144:     return 0;
                    145: }
                    146: 
                    147: static int protocol_client_vencrypt_init(VncState *vs, uint8_t *data, size_t len)
                    148: {
                    149:     if (data[0] != 0 ||
                    150:         data[1] != 2) {
                    151:         VNC_DEBUG("Unsupported VeNCrypt protocol %d.%d\n", (int)data[0], (int)data[1]);
                    152:         vnc_write_u8(vs, 1); /* Reject version */
                    153:         vnc_flush(vs);
                    154:         vnc_client_error(vs);
                    155:     } else {
                    156:         VNC_DEBUG("Sending allowed auth %d\n", vs->vd->subauth);
                    157:         vnc_write_u8(vs, 0); /* Accept version */
                    158:         vnc_write_u8(vs, 1); /* Number of sub-auths */
                    159:         vnc_write_u32(vs, vs->vd->subauth); /* The supported auth */
                    160:         vnc_flush(vs);
                    161:         vnc_read_when(vs, protocol_client_vencrypt_auth, 4);
                    162:     }
                    163:     return 0;
                    164: }
                    165: 
                    166: 
                    167: void start_auth_vencrypt(VncState *vs)
                    168: {
                    169:     /* Send VeNCrypt version 0.2 */
                    170:     vnc_write_u8(vs, 0);
                    171:     vnc_write_u8(vs, 2);
                    172: 
                    173:     vnc_read_when(vs, protocol_client_vencrypt_init, 2);
                    174: }
                    175: 

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