| /* | 
 |  * QEMU VNC display driver: SASL auth protocol | 
 |  * | 
 |  * Copyright (C) 2009 Red Hat, Inc | 
 |  * | 
 |  * Permission is hereby granted, free of charge, to any person obtaining a copy | 
 |  * of this software and associated documentation files (the "Software"), to deal | 
 |  * in the Software without restriction, including without limitation the rights | 
 |  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | 
 |  * copies of the Software, and to permit persons to whom the Software is | 
 |  * furnished to do so, subject to the following conditions: | 
 |  * | 
 |  * The above copyright notice and this permission notice shall be included in | 
 |  * all copies or substantial portions of the Software. | 
 |  * | 
 |  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | 
 |  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | 
 |  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | 
 |  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | 
 |  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | 
 |  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN | 
 |  * THE SOFTWARE. | 
 |  */ | 
 |  | 
 | #include "qemu/osdep.h" | 
 | #include "qapi/error.h" | 
 | #include "authz/base.h" | 
 | #include "vnc.h" | 
 | #include "trace.h" | 
 |  | 
 | /* | 
 |  * Apple has deprecated sasl.h functions in OS X 10.11.  Therefore, | 
 |  * files that use SASL API need to disable -Wdeprecated-declarations. | 
 |  */ | 
 | #ifdef CONFIG_DARWIN | 
 | #pragma GCC diagnostic ignored "-Wdeprecated-declarations" | 
 | #endif | 
 |  | 
 | /* Max amount of data we send/recv for SASL steps to prevent DOS */ | 
 | #define SASL_DATA_MAX_LEN (1024 * 1024) | 
 |  | 
 |  | 
 | bool vnc_sasl_server_init(Error **errp) | 
 | { | 
 |     int saslErr = sasl_server_init(NULL, "qemu"); | 
 |  | 
 |     if (saslErr != SASL_OK) { | 
 |         error_setg(errp, "Failed to initialize SASL auth: %s", | 
 |                    sasl_errstring(saslErr, NULL, NULL)); | 
 |         return false; | 
 |     } | 
 |     return true; | 
 | } | 
 |  | 
 | void vnc_sasl_client_cleanup(VncState *vs) | 
 | { | 
 |     if (vs->sasl.conn) { | 
 |         vs->sasl.runSSF = false; | 
 |         vs->sasl.wantSSF = false; | 
 |         vs->sasl.waitWriteSSF = 0; | 
 |         vs->sasl.encodedLength = vs->sasl.encodedOffset = 0; | 
 |         vs->sasl.encoded = NULL; | 
 |         g_free(vs->sasl.username); | 
 |         g_free(vs->sasl.mechlist); | 
 |         vs->sasl.username = vs->sasl.mechlist = NULL; | 
 |         sasl_dispose(&vs->sasl.conn); | 
 |         vs->sasl.conn = NULL; | 
 |     } | 
 | } | 
 |  | 
 |  | 
 | size_t vnc_client_write_sasl(VncState *vs) | 
 | { | 
 |     size_t ret; | 
 |  | 
 |     VNC_DEBUG("Write SASL: Pending output %p size %zd offset %zd " | 
 |               "Encoded: %p size %d offset %d\n", | 
 |               vs->output.buffer, vs->output.capacity, vs->output.offset, | 
 |               vs->sasl.encoded, vs->sasl.encodedLength, vs->sasl.encodedOffset); | 
 |  | 
 |     if (!vs->sasl.encoded) { | 
 |         int err; | 
 |         err = sasl_encode(vs->sasl.conn, | 
 |                           (char *)vs->output.buffer, | 
 |                           vs->output.offset, | 
 |                           (const char **)&vs->sasl.encoded, | 
 |                           &vs->sasl.encodedLength); | 
 |         if (err != SASL_OK) | 
 |             return vnc_client_io_error(vs, -1, NULL); | 
 |  | 
 |         vs->sasl.encodedRawLength = vs->output.offset; | 
 |         vs->sasl.encodedOffset = 0; | 
 |     } | 
 |  | 
 |     ret = vnc_client_write_buf(vs, | 
 |                                vs->sasl.encoded + vs->sasl.encodedOffset, | 
 |                                vs->sasl.encodedLength - vs->sasl.encodedOffset); | 
 |     if (!ret) | 
 |         return 0; | 
 |  | 
 |     vs->sasl.encodedOffset += ret; | 
 |     if (vs->sasl.encodedOffset == vs->sasl.encodedLength) { | 
 |         bool throttled = vs->force_update_offset != 0; | 
 |         size_t offset; | 
 |         if (vs->sasl.encodedRawLength >= vs->force_update_offset) { | 
 |             vs->force_update_offset = 0; | 
 |         } else { | 
 |             vs->force_update_offset -= vs->sasl.encodedRawLength; | 
 |         } | 
 |         if (throttled && vs->force_update_offset == 0) { | 
 |             trace_vnc_client_unthrottle_forced(vs, vs->ioc); | 
 |         } | 
 |         offset = vs->output.offset; | 
 |         buffer_advance(&vs->output, vs->sasl.encodedRawLength); | 
 |         if (offset >= vs->throttle_output_offset && | 
 |             vs->output.offset < vs->throttle_output_offset) { | 
 |             trace_vnc_client_unthrottle_incremental(vs, vs->ioc, | 
 |                                                     vs->output.offset); | 
 |         } | 
 |         vs->sasl.encoded = NULL; | 
 |         vs->sasl.encodedOffset = vs->sasl.encodedLength = 0; | 
 |     } | 
 |  | 
 |     /* Can't merge this block with one above, because | 
 |      * someone might have written more unencrypted | 
 |      * data in vs->output while we were processing | 
 |      * SASL encoded output | 
 |      */ | 
 |     if (vs->output.offset == 0) { | 
 |         if (vs->ioc_tag) { | 
 |             g_source_remove(vs->ioc_tag); | 
 |         } | 
 |         vs->ioc_tag = qio_channel_add_watch( | 
 |             vs->ioc, G_IO_IN | G_IO_HUP | G_IO_ERR, | 
 |             vnc_client_io, vs, NULL); | 
 |     } | 
 |  | 
 |     return ret; | 
 | } | 
 |  | 
 |  | 
 | size_t vnc_client_read_sasl(VncState *vs) | 
 | { | 
 |     size_t ret; | 
 |     uint8_t encoded[4096]; | 
 |     const char *decoded; | 
 |     unsigned int decodedLen; | 
 |     int err; | 
 |  | 
 |     ret = vnc_client_read_buf(vs, encoded, sizeof(encoded)); | 
 |     if (!ret) | 
 |         return 0; | 
 |  | 
 |     err = sasl_decode(vs->sasl.conn, | 
 |                       (char *)encoded, ret, | 
 |                       &decoded, &decodedLen); | 
 |  | 
 |     if (err != SASL_OK) | 
 |         return vnc_client_io_error(vs, -1, NULL); | 
 |     VNC_DEBUG("Read SASL Encoded %p size %ld Decoded %p size %d\n", | 
 |               encoded, ret, decoded, decodedLen); | 
 |     buffer_reserve(&vs->input, decodedLen); | 
 |     buffer_append(&vs->input, decoded, decodedLen); | 
 |     return decodedLen; | 
 | } | 
 |  | 
 |  | 
 | static int vnc_auth_sasl_check_access(VncState *vs) | 
 | { | 
 |     const void *val; | 
 |     int rv; | 
 |     Error *err = NULL; | 
 |     bool allow; | 
 |  | 
 |     rv = sasl_getprop(vs->sasl.conn, SASL_USERNAME, &val); | 
 |     if (rv != SASL_OK) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "Cannot fetch SASL username", | 
 |                             sasl_errstring(rv, NULL, NULL)); | 
 |         return -1; | 
 |     } | 
 |     if (val == NULL) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "No SASL username set", ""); | 
 |         return -1; | 
 |     } | 
 |  | 
 |     vs->sasl.username = g_strdup((const char*)val); | 
 |     trace_vnc_auth_sasl_username(vs, vs->sasl.username); | 
 |  | 
 |     if (vs->vd->sasl.authzid == NULL) { | 
 |         trace_vnc_auth_sasl_acl(vs, 1); | 
 |         return 0; | 
 |     } | 
 |  | 
 |     allow = qauthz_is_allowed_by_id(vs->vd->sasl.authzid, | 
 |                                     vs->sasl.username, &err); | 
 |     if (err) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "Error from authz", | 
 |                             error_get_pretty(err)); | 
 |         error_free(err); | 
 |         return -1; | 
 |     } | 
 |  | 
 |     trace_vnc_auth_sasl_acl(vs, allow); | 
 |     return allow ? 0 : -1; | 
 | } | 
 |  | 
 | static int vnc_auth_sasl_check_ssf(VncState *vs) | 
 | { | 
 |     const void *val; | 
 |     int err, ssf; | 
 |  | 
 |     if (!vs->sasl.wantSSF) | 
 |         return 1; | 
 |  | 
 |     err = sasl_getprop(vs->sasl.conn, SASL_SSF, &val); | 
 |     if (err != SASL_OK) | 
 |         return 0; | 
 |  | 
 |     ssf = *(const int *)val; | 
 |  | 
 |     trace_vnc_auth_sasl_ssf(vs, ssf); | 
 |  | 
 |     if (ssf < 56) | 
 |         return 0; /* 56 is good for Kerberos */ | 
 |  | 
 |     /* Only setup for read initially, because we're about to send an RPC | 
 |      * reply which must be in plain text. When the next incoming RPC | 
 |      * arrives, we'll switch on writes too | 
 |      * | 
 |      * cf qemudClientReadSASL  in qemud.c | 
 |      */ | 
 |     vs->sasl.runSSF = 1; | 
 |  | 
 |     /* We have a SSF that's good enough */ | 
 |     return 1; | 
 | } | 
 |  | 
 | /* | 
 |  * Step Msg | 
 |  * | 
 |  * Input from client: | 
 |  * | 
 |  * u32 clientin-length | 
 |  * u8-array clientin-string | 
 |  * | 
 |  * Output to client: | 
 |  * | 
 |  * u32 serverout-length | 
 |  * u8-array serverout-strin | 
 |  * u8 continue | 
 |  */ | 
 |  | 
 | static int protocol_client_auth_sasl_step_len(VncState *vs, uint8_t *data, size_t len); | 
 |  | 
 | static int protocol_client_auth_sasl_step(VncState *vs, uint8_t *data, size_t len) | 
 | { | 
 |     uint32_t datalen = len; | 
 |     const char *serverout; | 
 |     unsigned int serveroutlen; | 
 |     int err; | 
 |     char *clientdata = NULL; | 
 |  | 
 |     /* NB, distinction of NULL vs "" is *critical* in SASL */ | 
 |     if (datalen) { | 
 |         clientdata = (char*)data; | 
 |         clientdata[datalen-1] = '\0'; /* Wire includes '\0', but make sure */ | 
 |         datalen--; /* Don't count NULL byte when passing to _start() */ | 
 |     } | 
 |  | 
 |     err = sasl_server_step(vs->sasl.conn, | 
 |                            clientdata, | 
 |                            datalen, | 
 |                            &serverout, | 
 |                            &serveroutlen); | 
 |     trace_vnc_auth_sasl_step(vs, data, len, serverout, serveroutlen, err); | 
 |     if (err != SASL_OK && | 
 |         err != SASL_CONTINUE) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "Cannot step SASL auth", | 
 |                             sasl_errdetail(vs->sasl.conn)); | 
 |         sasl_dispose(&vs->sasl.conn); | 
 |         vs->sasl.conn = NULL; | 
 |         goto authabort; | 
 |     } | 
 |  | 
 |     if (serveroutlen > SASL_DATA_MAX_LEN) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "SASL data too long", ""); | 
 |         sasl_dispose(&vs->sasl.conn); | 
 |         vs->sasl.conn = NULL; | 
 |         goto authabort; | 
 |     } | 
 |  | 
 |     if (serveroutlen) { | 
 |         vnc_write_u32(vs, serveroutlen + 1); | 
 |         vnc_write(vs, serverout, serveroutlen + 1); | 
 |     } else { | 
 |         vnc_write_u32(vs, 0); | 
 |     } | 
 |  | 
 |     /* Whether auth is complete */ | 
 |     vnc_write_u8(vs, err == SASL_CONTINUE ? 0 : 1); | 
 |  | 
 |     if (err == SASL_CONTINUE) { | 
 |         /* Wait for step length */ | 
 |         vnc_read_when(vs, protocol_client_auth_sasl_step_len, 4); | 
 |     } else { | 
 |         if (!vnc_auth_sasl_check_ssf(vs)) { | 
 |             trace_vnc_auth_fail(vs, vs->auth, "SASL SSF too weak", ""); | 
 |             goto authreject; | 
 |         } | 
 |  | 
 |         /* Check the username access control list */ | 
 |         if (vnc_auth_sasl_check_access(vs) < 0) { | 
 |             goto authreject; | 
 |         } | 
 |  | 
 |         trace_vnc_auth_pass(vs, vs->auth); | 
 |         vnc_write_u32(vs, 0); /* Accept auth */ | 
 |         /* | 
 |          * Delay writing in SSF encoded mode until pending output | 
 |          * buffer is written | 
 |          */ | 
 |         if (vs->sasl.runSSF) | 
 |             vs->sasl.waitWriteSSF = vs->output.offset; | 
 |         start_client_init(vs); | 
 |     } | 
 |  | 
 |     return 0; | 
 |  | 
 |  authreject: | 
 |     vnc_write_u32(vs, 1); /* Reject auth */ | 
 |     vnc_write_u32(vs, sizeof("Authentication failed")); | 
 |     vnc_write(vs, "Authentication failed", sizeof("Authentication failed")); | 
 |     vnc_flush(vs); | 
 |     vnc_client_error(vs); | 
 |     return -1; | 
 |  | 
 |  authabort: | 
 |     vnc_client_error(vs); | 
 |     return -1; | 
 | } | 
 |  | 
 | static int protocol_client_auth_sasl_step_len(VncState *vs, uint8_t *data, size_t len) | 
 | { | 
 |     uint32_t steplen = read_u32(data, 0); | 
 |  | 
 |     if (steplen > SASL_DATA_MAX_LEN) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "SASL step len too large", ""); | 
 |         vnc_client_error(vs); | 
 |         return -1; | 
 |     } | 
 |  | 
 |     if (steplen == 0) | 
 |         return protocol_client_auth_sasl_step(vs, NULL, 0); | 
 |     else | 
 |         vnc_read_when(vs, protocol_client_auth_sasl_step, steplen); | 
 |     return 0; | 
 | } | 
 |  | 
 | /* | 
 |  * Start Msg | 
 |  * | 
 |  * Input from client: | 
 |  * | 
 |  * u32 clientin-length | 
 |  * u8-array clientin-string | 
 |  * | 
 |  * Output to client: | 
 |  * | 
 |  * u32 serverout-length | 
 |  * u8-array serverout-strin | 
 |  * u8 continue | 
 |  */ | 
 |  | 
 | #define SASL_DATA_MAX_LEN (1024 * 1024) | 
 |  | 
 | static int protocol_client_auth_sasl_start(VncState *vs, uint8_t *data, size_t len) | 
 | { | 
 |     uint32_t datalen = len; | 
 |     const char *serverout; | 
 |     unsigned int serveroutlen; | 
 |     int err; | 
 |     char *clientdata = NULL; | 
 |  | 
 |     /* NB, distinction of NULL vs "" is *critical* in SASL */ | 
 |     if (datalen) { | 
 |         clientdata = (char*)data; | 
 |         clientdata[datalen-1] = '\0'; /* Should be on wire, but make sure */ | 
 |         datalen--; /* Don't count NULL byte when passing to _start() */ | 
 |     } | 
 |  | 
 |     err = sasl_server_start(vs->sasl.conn, | 
 |                             vs->sasl.mechlist, | 
 |                             clientdata, | 
 |                             datalen, | 
 |                             &serverout, | 
 |                             &serveroutlen); | 
 |     trace_vnc_auth_sasl_start(vs, data, len, serverout, serveroutlen, err); | 
 |     if (err != SASL_OK && | 
 |         err != SASL_CONTINUE) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "Cannot start SASL auth", | 
 |                             sasl_errdetail(vs->sasl.conn)); | 
 |         sasl_dispose(&vs->sasl.conn); | 
 |         vs->sasl.conn = NULL; | 
 |         goto authabort; | 
 |     } | 
 |     if (serveroutlen > SASL_DATA_MAX_LEN) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "SASL data too long", ""); | 
 |         sasl_dispose(&vs->sasl.conn); | 
 |         vs->sasl.conn = NULL; | 
 |         goto authabort; | 
 |     } | 
 |  | 
 |     if (serveroutlen) { | 
 |         vnc_write_u32(vs, serveroutlen + 1); | 
 |         vnc_write(vs, serverout, serveroutlen + 1); | 
 |     } else { | 
 |         vnc_write_u32(vs, 0); | 
 |     } | 
 |  | 
 |     /* Whether auth is complete */ | 
 |     vnc_write_u8(vs, err == SASL_CONTINUE ? 0 : 1); | 
 |  | 
 |     if (err == SASL_CONTINUE) { | 
 |         /* Wait for step length */ | 
 |         vnc_read_when(vs, protocol_client_auth_sasl_step_len, 4); | 
 |     } else { | 
 |         if (!vnc_auth_sasl_check_ssf(vs)) { | 
 |             trace_vnc_auth_fail(vs, vs->auth, "SASL SSF too weak", ""); | 
 |             goto authreject; | 
 |         } | 
 |  | 
 |         /* Check the username access control list */ | 
 |         if (vnc_auth_sasl_check_access(vs) < 0) { | 
 |             goto authreject; | 
 |         } | 
 |  | 
 |         trace_vnc_auth_pass(vs, vs->auth); | 
 |         vnc_write_u32(vs, 0); /* Accept auth */ | 
 |         start_client_init(vs); | 
 |     } | 
 |  | 
 |     return 0; | 
 |  | 
 |  authreject: | 
 |     vnc_write_u32(vs, 1); /* Reject auth */ | 
 |     vnc_write_u32(vs, sizeof("Authentication failed")); | 
 |     vnc_write(vs, "Authentication failed", sizeof("Authentication failed")); | 
 |     vnc_flush(vs); | 
 |     vnc_client_error(vs); | 
 |     return -1; | 
 |  | 
 |  authabort: | 
 |     vnc_client_error(vs); | 
 |     return -1; | 
 | } | 
 |  | 
 | static int protocol_client_auth_sasl_start_len(VncState *vs, uint8_t *data, size_t len) | 
 | { | 
 |     uint32_t startlen = read_u32(data, 0); | 
 |  | 
 |     if (startlen > SASL_DATA_MAX_LEN) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "SASL start len too large", ""); | 
 |         vnc_client_error(vs); | 
 |         return -1; | 
 |     } | 
 |  | 
 |     if (startlen == 0) | 
 |         return protocol_client_auth_sasl_start(vs, NULL, 0); | 
 |  | 
 |     vnc_read_when(vs, protocol_client_auth_sasl_start, startlen); | 
 |     return 0; | 
 | } | 
 |  | 
 | static int protocol_client_auth_sasl_mechname(VncState *vs, uint8_t *data, size_t len) | 
 | { | 
 |     char *mechname = g_strndup((const char *) data, len); | 
 |     trace_vnc_auth_sasl_mech_choose(vs, mechname); | 
 |  | 
 |     if (strncmp(vs->sasl.mechlist, mechname, len) == 0) { | 
 |         if (vs->sasl.mechlist[len] != '\0' && | 
 |             vs->sasl.mechlist[len] != ',') { | 
 |             goto fail; | 
 |         } | 
 |     } else { | 
 |         char *offset = strstr(vs->sasl.mechlist, mechname); | 
 |         if (!offset) { | 
 |             goto fail; | 
 |         } | 
 |         if (offset[-1] != ',' || | 
 |             (offset[len] != '\0'&& | 
 |              offset[len] != ',')) { | 
 |             goto fail; | 
 |         } | 
 |     } | 
 |  | 
 |     g_free(vs->sasl.mechlist); | 
 |     vs->sasl.mechlist = mechname; | 
 |  | 
 |     vnc_read_when(vs, protocol_client_auth_sasl_start_len, 4); | 
 |     return 0; | 
 |  | 
 |  fail: | 
 |     trace_vnc_auth_fail(vs, vs->auth, "Unsupported mechname", mechname); | 
 |     vnc_client_error(vs); | 
 |     g_free(mechname); | 
 |     return -1; | 
 | } | 
 |  | 
 | static int protocol_client_auth_sasl_mechname_len(VncState *vs, uint8_t *data, size_t len) | 
 | { | 
 |     uint32_t mechlen = read_u32(data, 0); | 
 |  | 
 |     if (mechlen > 100) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "SASL mechname too long", ""); | 
 |         vnc_client_error(vs); | 
 |         return -1; | 
 |     } | 
 |     if (mechlen < 1) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "SASL mechname too short", ""); | 
 |         vnc_client_error(vs); | 
 |         return -1; | 
 |     } | 
 |     vnc_read_when(vs, protocol_client_auth_sasl_mechname,mechlen); | 
 |     return 0; | 
 | } | 
 |  | 
 | static char * | 
 | vnc_socket_ip_addr_string(QIOChannelSocket *ioc, | 
 |                           bool local, | 
 |                           Error **errp) | 
 | { | 
 |     SocketAddress *addr; | 
 |     char *ret; | 
 |  | 
 |     if (local) { | 
 |         addr = qio_channel_socket_get_local_address(ioc, errp); | 
 |     } else { | 
 |         addr = qio_channel_socket_get_remote_address(ioc, errp); | 
 |     } | 
 |     if (!addr) { | 
 |         return NULL; | 
 |     } | 
 |  | 
 |     if (addr->type != SOCKET_ADDRESS_TYPE_INET) { | 
 |         error_setg(errp, "Not an inet socket type"); | 
 |         qapi_free_SocketAddress(addr); | 
 |         return NULL; | 
 |     } | 
 |     ret = g_strdup_printf("%s;%s", addr->u.inet.host, addr->u.inet.port); | 
 |     qapi_free_SocketAddress(addr); | 
 |     return ret; | 
 | } | 
 |  | 
 | void start_auth_sasl(VncState *vs) | 
 | { | 
 |     const char *mechlist = NULL; | 
 |     sasl_security_properties_t secprops; | 
 |     int err; | 
 |     Error *local_err = NULL; | 
 |     char *localAddr, *remoteAddr; | 
 |     int mechlistlen; | 
 |  | 
 |     /* Get local & remote client addresses in form  IPADDR;PORT */ | 
 |     localAddr = vnc_socket_ip_addr_string(vs->sioc, true, &local_err); | 
 |     if (!localAddr) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "Cannot format local IP", | 
 |                             error_get_pretty(local_err)); | 
 |         goto authabort; | 
 |     } | 
 |  | 
 |     remoteAddr = vnc_socket_ip_addr_string(vs->sioc, false, &local_err); | 
 |     if (!remoteAddr) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "Cannot format remote IP", | 
 |                             error_get_pretty(local_err)); | 
 |         g_free(localAddr); | 
 |         goto authabort; | 
 |     } | 
 |  | 
 |     err = sasl_server_new("vnc", | 
 |                           NULL, /* FQDN - just delegates to gethostname */ | 
 |                           NULL, /* User realm */ | 
 |                           localAddr, | 
 |                           remoteAddr, | 
 |                           NULL, /* Callbacks, not needed */ | 
 |                           SASL_SUCCESS_DATA, | 
 |                           &vs->sasl.conn); | 
 |     g_free(localAddr); | 
 |     g_free(remoteAddr); | 
 |     localAddr = remoteAddr = NULL; | 
 |  | 
 |     if (err != SASL_OK) { | 
 |         trace_vnc_auth_fail(vs, vs->auth,  "SASL context setup failed", | 
 |                             sasl_errstring(err, NULL, NULL)); | 
 |         vs->sasl.conn = NULL; | 
 |         goto authabort; | 
 |     } | 
 |  | 
 |     /* Inform SASL that we've got an external SSF layer from TLS/x509 */ | 
 |     if (vs->auth == VNC_AUTH_VENCRYPT && | 
 |         vs->subauth == VNC_AUTH_VENCRYPT_X509SASL) { | 
 |         int keysize; | 
 |         sasl_ssf_t ssf; | 
 |  | 
 |         keysize = qcrypto_tls_session_get_key_size(vs->tls, | 
 |                                                    &local_err); | 
 |         if (keysize < 0) { | 
 |             trace_vnc_auth_fail(vs, vs->auth, "cannot TLS get cipher size", | 
 |                                 error_get_pretty(local_err)); | 
 |             sasl_dispose(&vs->sasl.conn); | 
 |             vs->sasl.conn = NULL; | 
 |             goto authabort; | 
 |         } | 
 |         ssf = keysize * CHAR_BIT; /* tls key size is bytes, sasl wants bits */ | 
 |  | 
 |         err = sasl_setprop(vs->sasl.conn, SASL_SSF_EXTERNAL, &ssf); | 
 |         if (err != SASL_OK) { | 
 |             trace_vnc_auth_fail(vs, vs->auth, "cannot set SASL external SSF", | 
 |                                 sasl_errstring(err, NULL, NULL)); | 
 |             sasl_dispose(&vs->sasl.conn); | 
 |             vs->sasl.conn = NULL; | 
 |             goto authabort; | 
 |         } | 
 |     } else { | 
 |         vs->sasl.wantSSF = 1; | 
 |     } | 
 |  | 
 |     memset (&secprops, 0, sizeof secprops); | 
 |     /* Inform SASL that we've got an external SSF layer from TLS. | 
 |      * | 
 |      * Disable SSF, if using TLS+x509+SASL only. TLS without x509 | 
 |      * is not sufficiently strong | 
 |      */ | 
 |     if (vs->vd->is_unix || | 
 |         (vs->auth == VNC_AUTH_VENCRYPT && | 
 |          vs->subauth == VNC_AUTH_VENCRYPT_X509SASL)) { | 
 |         /* If we've got TLS or UNIX domain sock, we don't care about SSF */ | 
 |         secprops.min_ssf = 0; | 
 |         secprops.max_ssf = 0; | 
 |         secprops.maxbufsize = 8192; | 
 |         secprops.security_flags = 0; | 
 |     } else { | 
 |         /* Plain TCP, better get an SSF layer */ | 
 |         secprops.min_ssf = 56; /* Good enough to require kerberos */ | 
 |         secprops.max_ssf = 100000; /* Arbitrary big number */ | 
 |         secprops.maxbufsize = 8192; | 
 |         /* Forbid any anonymous or trivially crackable auth */ | 
 |         secprops.security_flags = | 
 |             SASL_SEC_NOANONYMOUS | SASL_SEC_NOPLAINTEXT; | 
 |     } | 
 |  | 
 |     err = sasl_setprop(vs->sasl.conn, SASL_SEC_PROPS, &secprops); | 
 |     if (err != SASL_OK) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "cannot set SASL security props", | 
 |                             sasl_errstring(err, NULL, NULL)); | 
 |         sasl_dispose(&vs->sasl.conn); | 
 |         vs->sasl.conn = NULL; | 
 |         goto authabort; | 
 |     } | 
 |  | 
 |     err = sasl_listmech(vs->sasl.conn, | 
 |                         NULL, /* Don't need to set user */ | 
 |                         "", /* Prefix */ | 
 |                         ",", /* Separator */ | 
 |                         "", /* Suffix */ | 
 |                         &mechlist, | 
 |                         NULL, | 
 |                         NULL); | 
 |     if (err != SASL_OK) { | 
 |         trace_vnc_auth_fail(vs, vs->auth, "cannot list SASL mechanisms", | 
 |                             sasl_errdetail(vs->sasl.conn)); | 
 |         sasl_dispose(&vs->sasl.conn); | 
 |         vs->sasl.conn = NULL; | 
 |         goto authabort; | 
 |     } | 
 |     trace_vnc_auth_sasl_mech_list(vs, mechlist); | 
 |  | 
 |     vs->sasl.mechlist = g_strdup(mechlist); | 
 |     mechlistlen = strlen(mechlist); | 
 |     vnc_write_u32(vs, mechlistlen); | 
 |     vnc_write(vs, mechlist, mechlistlen); | 
 |     vnc_flush(vs); | 
 |  | 
 |     vnc_read_when(vs, protocol_client_auth_sasl_mechname_len, 4); | 
 |  | 
 |     return; | 
 |  | 
 |  authabort: | 
 |     error_free(local_err); | 
 |     vnc_client_error(vs); | 
 | } | 
 |  | 
 |  |