root / ui / vnc-auth-sasl.c @ 7fee199c
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/*
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* QEMU VNC display driver: SASL auth protocol
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*
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* Copyright (C) 2009 Red Hat, Inc
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "vnc.h" |
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/* Max amount of data we send/recv for SASL steps to prevent DOS */
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#define SASL_DATA_MAX_LEN (1024 * 1024) |
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void vnc_sasl_client_cleanup(VncState *vs)
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{
|
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if (vs->sasl.conn) {
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vs->sasl.runSSF = vs->sasl.waitWriteSSF = vs->sasl.wantSSF = 0;
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vs->sasl.encodedLength = vs->sasl.encodedOffset = 0;
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vs->sasl.encoded = NULL;
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free(vs->sasl.username); |
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free(vs->sasl.mechlist); |
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vs->sasl.username = vs->sasl.mechlist = NULL;
|
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sasl_dispose(&vs->sasl.conn); |
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vs->sasl.conn = NULL;
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} |
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} |
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|
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|
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long vnc_client_write_sasl(VncState *vs)
|
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{
|
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long ret;
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|
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VNC_DEBUG("Write SASL: Pending output %p size %zd offset %zd "
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"Encoded: %p size %d offset %d\n",
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vs->output.buffer, vs->output.capacity, vs->output.offset, |
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vs->sasl.encoded, vs->sasl.encodedLength, vs->sasl.encodedOffset); |
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|
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if (!vs->sasl.encoded) {
|
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int err;
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err = sasl_encode(vs->sasl.conn, |
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(char *)vs->output.buffer,
|
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vs->output.offset, |
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(const char **)&vs->sasl.encoded, |
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&vs->sasl.encodedLength); |
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if (err != SASL_OK)
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return vnc_client_io_error(vs, -1, EIO); |
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|
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vs->sasl.encodedOffset = 0;
|
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} |
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|
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ret = vnc_client_write_buf(vs, |
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vs->sasl.encoded + vs->sasl.encodedOffset, |
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vs->sasl.encodedLength - vs->sasl.encodedOffset); |
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if (!ret)
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return 0; |
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|
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vs->sasl.encodedOffset += ret; |
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if (vs->sasl.encodedOffset == vs->sasl.encodedLength) {
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vs->output.offset = 0;
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vs->sasl.encoded = NULL;
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vs->sasl.encodedOffset = vs->sasl.encodedLength = 0;
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} |
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|
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/* Can't merge this block with one above, because
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* someone might have written more unencrypted
|
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* data in vs->output while we were processing
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* SASL encoded output
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*/
|
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if (vs->output.offset == 0) { |
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qemu_set_fd_handler2(vs->csock, NULL, vnc_client_read, NULL, vs); |
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} |
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return ret;
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} |
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|
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long vnc_client_read_sasl(VncState *vs)
|
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{
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long ret;
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uint8_t encoded[4096];
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const char *decoded; |
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unsigned int decodedLen; |
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int err;
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ret = vnc_client_read_buf(vs, encoded, sizeof(encoded));
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if (!ret)
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return 0; |
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|
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err = sasl_decode(vs->sasl.conn, |
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(char *)encoded, ret,
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&decoded, &decodedLen); |
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|
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if (err != SASL_OK)
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return vnc_client_io_error(vs, -1, -EIO); |
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VNC_DEBUG("Read SASL Encoded %p size %ld Decoded %p size %d\n",
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encoded, ret, decoded, decodedLen); |
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buffer_reserve(&vs->input, decodedLen); |
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buffer_append(&vs->input, decoded, decodedLen); |
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return decodedLen;
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} |
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|
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static int vnc_auth_sasl_check_access(VncState *vs) |
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{
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const void *val; |
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int err;
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int allow;
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|
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err = sasl_getprop(vs->sasl.conn, SASL_USERNAME, &val); |
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if (err != SASL_OK) {
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VNC_DEBUG("cannot query SASL username on connection %d (%s), denying access\n",
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err, sasl_errstring(err, NULL, NULL)); |
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return -1; |
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} |
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if (val == NULL) { |
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VNC_DEBUG("no client username was found, denying access\n");
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return -1; |
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} |
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VNC_DEBUG("SASL client username %s\n", (const char *)val); |
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|
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vs->sasl.username = qemu_strdup((const char*)val); |
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|
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if (vs->vd->sasl.acl == NULL) { |
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VNC_DEBUG("no ACL activated, allowing access\n");
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return 0; |
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} |
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|
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allow = qemu_acl_party_is_allowed(vs->vd->sasl.acl, vs->sasl.username); |
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VNC_DEBUG("SASL client %s %s by ACL\n", vs->sasl.username,
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allow ? "allowed" : "denied"); |
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return allow ? 0 : -1; |
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} |
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|
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static int vnc_auth_sasl_check_ssf(VncState *vs) |
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{
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const void *val; |
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int err, ssf;
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|
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if (!vs->sasl.wantSSF)
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return 1; |
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err = sasl_getprop(vs->sasl.conn, SASL_SSF, &val); |
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if (err != SASL_OK)
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return 0; |
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ssf = *(const int *)val; |
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VNC_DEBUG("negotiated an SSF of %d\n", ssf);
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if (ssf < 56) |
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return 0; /* 56 is good for Kerberos */ |
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/* Only setup for read initially, because we're about to send an RPC
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* reply which must be in plain text. When the next incoming RPC
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* arrives, we'll switch on writes too
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*
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* cf qemudClientReadSASL in qemud.c
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*/
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vs->sasl.runSSF = 1;
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/* We have a SSF that's good enough */
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return 1; |
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} |
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/*
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* Step Msg
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*
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* Input from client:
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*
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* u32 clientin-length
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* u8-array clientin-string
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*
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* Output to client:
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*
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* u32 serverout-length
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* u8-array serverout-strin
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* u8 continue
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*/
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static int protocol_client_auth_sasl_step_len(VncState *vs, uint8_t *data, size_t len); |
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static int protocol_client_auth_sasl_step(VncState *vs, uint8_t *data, size_t len) |
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{
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uint32_t datalen = len; |
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const char *serverout; |
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unsigned int serveroutlen; |
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int err;
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char *clientdata = NULL; |
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/* NB, distinction of NULL vs "" is *critical* in SASL */
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if (datalen) {
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clientdata = (char*)data;
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clientdata[datalen-1] = '\0'; /* Wire includes '\0', but make sure */ |
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datalen--; /* Don't count NULL byte when passing to _start() */
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} |
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VNC_DEBUG("Step using SASL Data %p (%d bytes)\n",
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clientdata, datalen); |
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err = sasl_server_step(vs->sasl.conn, |
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clientdata, |
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datalen, |
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&serverout, |
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&serveroutlen); |
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if (err != SASL_OK &&
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err != SASL_CONTINUE) {
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VNC_DEBUG("sasl step failed %d (%s)\n",
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err, sasl_errdetail(vs->sasl.conn)); |
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sasl_dispose(&vs->sasl.conn); |
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vs->sasl.conn = NULL;
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goto authabort;
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} |
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|
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if (serveroutlen > SASL_DATA_MAX_LEN) {
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VNC_DEBUG("sasl step reply data too long %d\n",
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serveroutlen); |
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sasl_dispose(&vs->sasl.conn); |
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vs->sasl.conn = NULL;
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goto authabort;
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} |
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|
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VNC_DEBUG("SASL return data %d bytes, nil; %d\n",
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serveroutlen, serverout ? 0 : 1); |
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|
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if (serveroutlen) {
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vnc_write_u32(vs, serveroutlen + 1);
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vnc_write(vs, serverout, serveroutlen + 1);
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} else {
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vnc_write_u32(vs, 0);
|
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} |
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|
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/* Whether auth is complete */
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vnc_write_u8(vs, err == SASL_CONTINUE ? 0 : 1); |
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|
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if (err == SASL_CONTINUE) {
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VNC_DEBUG("%s", "Authentication must continue\n"); |
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/* Wait for step length */
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vnc_read_when(vs, protocol_client_auth_sasl_step_len, 4);
|
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} else {
|
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if (!vnc_auth_sasl_check_ssf(vs)) {
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VNC_DEBUG("Authentication rejected for weak SSF %d\n", vs->csock);
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goto authreject;
|
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} |
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|
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/* Check username whitelist ACL */
|
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if (vnc_auth_sasl_check_access(vs) < 0) { |
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VNC_DEBUG("Authentication rejected for ACL %d\n", vs->csock);
|
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goto authreject;
|
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} |
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|
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VNC_DEBUG("Authentication successful %d\n", vs->csock);
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vnc_write_u32(vs, 0); /* Accept auth */ |
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/*
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* Delay writing in SSF encoded mode until pending output
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* buffer is written
|
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*/
|
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if (vs->sasl.runSSF)
|
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vs->sasl.waitWriteSSF = vs->output.offset; |
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start_client_init(vs); |
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} |
| 276 |
|
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return 0; |
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|
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authreject:
|
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vnc_write_u32(vs, 1); /* Reject auth */ |
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vnc_write_u32(vs, sizeof("Authentication failed")); |
| 282 |
vnc_write(vs, "Authentication failed", sizeof("Authentication failed")); |
| 283 |
vnc_flush(vs); |
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vnc_client_error(vs); |
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return -1; |
| 286 |
|
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authabort:
|
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vnc_client_error(vs); |
| 289 |
return -1; |
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} |
| 291 |
|
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static int protocol_client_auth_sasl_step_len(VncState *vs, uint8_t *data, size_t len) |
| 293 |
{
|
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uint32_t steplen = read_u32(data, 0);
|
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VNC_DEBUG("Got client step len %d\n", steplen);
|
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if (steplen > SASL_DATA_MAX_LEN) {
|
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VNC_DEBUG("Too much SASL data %d\n", steplen);
|
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vnc_client_error(vs); |
| 299 |
return -1; |
| 300 |
} |
| 301 |
|
| 302 |
if (steplen == 0) |
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return protocol_client_auth_sasl_step(vs, NULL, 0); |
| 304 |
else
|
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vnc_read_when(vs, protocol_client_auth_sasl_step, steplen); |
| 306 |
return 0; |
| 307 |
} |
| 308 |
|
| 309 |
/*
|
| 310 |
* Start Msg
|
| 311 |
*
|
| 312 |
* Input from client:
|
| 313 |
*
|
| 314 |
* u32 clientin-length
|
| 315 |
* u8-array clientin-string
|
| 316 |
*
|
| 317 |
* Output to client:
|
| 318 |
*
|
| 319 |
* u32 serverout-length
|
| 320 |
* u8-array serverout-strin
|
| 321 |
* u8 continue
|
| 322 |
*/
|
| 323 |
|
| 324 |
#define SASL_DATA_MAX_LEN (1024 * 1024) |
| 325 |
|
| 326 |
static int protocol_client_auth_sasl_start(VncState *vs, uint8_t *data, size_t len) |
| 327 |
{
|
| 328 |
uint32_t datalen = len; |
| 329 |
const char *serverout; |
| 330 |
unsigned int serveroutlen; |
| 331 |
int err;
|
| 332 |
char *clientdata = NULL; |
| 333 |
|
| 334 |
/* NB, distinction of NULL vs "" is *critical* in SASL */
|
| 335 |
if (datalen) {
|
| 336 |
clientdata = (char*)data;
|
| 337 |
clientdata[datalen-1] = '\0'; /* Should be on wire, but make sure */ |
| 338 |
datalen--; /* Don't count NULL byte when passing to _start() */
|
| 339 |
} |
| 340 |
|
| 341 |
VNC_DEBUG("Start SASL auth with mechanism %s. Data %p (%d bytes)\n",
|
| 342 |
vs->sasl.mechlist, clientdata, datalen); |
| 343 |
err = sasl_server_start(vs->sasl.conn, |
| 344 |
vs->sasl.mechlist, |
| 345 |
clientdata, |
| 346 |
datalen, |
| 347 |
&serverout, |
| 348 |
&serveroutlen); |
| 349 |
if (err != SASL_OK &&
|
| 350 |
err != SASL_CONTINUE) {
|
| 351 |
VNC_DEBUG("sasl start failed %d (%s)\n",
|
| 352 |
err, sasl_errdetail(vs->sasl.conn)); |
| 353 |
sasl_dispose(&vs->sasl.conn); |
| 354 |
vs->sasl.conn = NULL;
|
| 355 |
goto authabort;
|
| 356 |
} |
| 357 |
if (serveroutlen > SASL_DATA_MAX_LEN) {
|
| 358 |
VNC_DEBUG("sasl start reply data too long %d\n",
|
| 359 |
serveroutlen); |
| 360 |
sasl_dispose(&vs->sasl.conn); |
| 361 |
vs->sasl.conn = NULL;
|
| 362 |
goto authabort;
|
| 363 |
} |
| 364 |
|
| 365 |
VNC_DEBUG("SASL return data %d bytes, nil; %d\n",
|
| 366 |
serveroutlen, serverout ? 0 : 1); |
| 367 |
|
| 368 |
if (serveroutlen) {
|
| 369 |
vnc_write_u32(vs, serveroutlen + 1);
|
| 370 |
vnc_write(vs, serverout, serveroutlen + 1);
|
| 371 |
} else {
|
| 372 |
vnc_write_u32(vs, 0);
|
| 373 |
} |
| 374 |
|
| 375 |
/* Whether auth is complete */
|
| 376 |
vnc_write_u8(vs, err == SASL_CONTINUE ? 0 : 1); |
| 377 |
|
| 378 |
if (err == SASL_CONTINUE) {
|
| 379 |
VNC_DEBUG("%s", "Authentication must continue\n"); |
| 380 |
/* Wait for step length */
|
| 381 |
vnc_read_when(vs, protocol_client_auth_sasl_step_len, 4);
|
| 382 |
} else {
|
| 383 |
if (!vnc_auth_sasl_check_ssf(vs)) {
|
| 384 |
VNC_DEBUG("Authentication rejected for weak SSF %d\n", vs->csock);
|
| 385 |
goto authreject;
|
| 386 |
} |
| 387 |
|
| 388 |
/* Check username whitelist ACL */
|
| 389 |
if (vnc_auth_sasl_check_access(vs) < 0) { |
| 390 |
VNC_DEBUG("Authentication rejected for ACL %d\n", vs->csock);
|
| 391 |
goto authreject;
|
| 392 |
} |
| 393 |
|
| 394 |
VNC_DEBUG("Authentication successful %d\n", vs->csock);
|
| 395 |
vnc_write_u32(vs, 0); /* Accept auth */ |
| 396 |
start_client_init(vs); |
| 397 |
} |
| 398 |
|
| 399 |
return 0; |
| 400 |
|
| 401 |
authreject:
|
| 402 |
vnc_write_u32(vs, 1); /* Reject auth */ |
| 403 |
vnc_write_u32(vs, sizeof("Authentication failed")); |
| 404 |
vnc_write(vs, "Authentication failed", sizeof("Authentication failed")); |
| 405 |
vnc_flush(vs); |
| 406 |
vnc_client_error(vs); |
| 407 |
return -1; |
| 408 |
|
| 409 |
authabort:
|
| 410 |
vnc_client_error(vs); |
| 411 |
return -1; |
| 412 |
} |
| 413 |
|
| 414 |
static int protocol_client_auth_sasl_start_len(VncState *vs, uint8_t *data, size_t len) |
| 415 |
{
|
| 416 |
uint32_t startlen = read_u32(data, 0);
|
| 417 |
VNC_DEBUG("Got client start len %d\n", startlen);
|
| 418 |
if (startlen > SASL_DATA_MAX_LEN) {
|
| 419 |
VNC_DEBUG("Too much SASL data %d\n", startlen);
|
| 420 |
vnc_client_error(vs); |
| 421 |
return -1; |
| 422 |
} |
| 423 |
|
| 424 |
if (startlen == 0) |
| 425 |
return protocol_client_auth_sasl_start(vs, NULL, 0); |
| 426 |
|
| 427 |
vnc_read_when(vs, protocol_client_auth_sasl_start, startlen); |
| 428 |
return 0; |
| 429 |
} |
| 430 |
|
| 431 |
static int protocol_client_auth_sasl_mechname(VncState *vs, uint8_t *data, size_t len) |
| 432 |
{
|
| 433 |
char *mechname = malloc(len + 1); |
| 434 |
if (!mechname) {
|
| 435 |
VNC_DEBUG("Out of memory reading mechname\n");
|
| 436 |
vnc_client_error(vs); |
| 437 |
} |
| 438 |
strncpy(mechname, (char*)data, len);
|
| 439 |
mechname[len] = '\0';
|
| 440 |
VNC_DEBUG("Got client mechname '%s' check against '%s'\n",
|
| 441 |
mechname, vs->sasl.mechlist); |
| 442 |
|
| 443 |
if (strncmp(vs->sasl.mechlist, mechname, len) == 0) { |
| 444 |
if (vs->sasl.mechlist[len] != '\0' && |
| 445 |
vs->sasl.mechlist[len] != ',') {
|
| 446 |
VNC_DEBUG("One %d", vs->sasl.mechlist[len]);
|
| 447 |
goto fail;
|
| 448 |
} |
| 449 |
} else {
|
| 450 |
char *offset = strstr(vs->sasl.mechlist, mechname);
|
| 451 |
VNC_DEBUG("Two %p\n", offset);
|
| 452 |
if (!offset) {
|
| 453 |
goto fail;
|
| 454 |
} |
| 455 |
VNC_DEBUG("Two '%s'\n", offset);
|
| 456 |
if (offset[-1] != ',' || |
| 457 |
(offset[len] != '\0'&&
|
| 458 |
offset[len] != ',')) {
|
| 459 |
goto fail;
|
| 460 |
} |
| 461 |
} |
| 462 |
|
| 463 |
free(vs->sasl.mechlist); |
| 464 |
vs->sasl.mechlist = mechname; |
| 465 |
|
| 466 |
VNC_DEBUG("Validated mechname '%s'\n", mechname);
|
| 467 |
vnc_read_when(vs, protocol_client_auth_sasl_start_len, 4);
|
| 468 |
return 0; |
| 469 |
|
| 470 |
fail:
|
| 471 |
vnc_client_error(vs); |
| 472 |
free(mechname); |
| 473 |
return -1; |
| 474 |
} |
| 475 |
|
| 476 |
static int protocol_client_auth_sasl_mechname_len(VncState *vs, uint8_t *data, size_t len) |
| 477 |
{
|
| 478 |
uint32_t mechlen = read_u32(data, 0);
|
| 479 |
VNC_DEBUG("Got client mechname len %d\n", mechlen);
|
| 480 |
if (mechlen > 100) { |
| 481 |
VNC_DEBUG("Too long SASL mechname data %d\n", mechlen);
|
| 482 |
vnc_client_error(vs); |
| 483 |
return -1; |
| 484 |
} |
| 485 |
if (mechlen < 1) { |
| 486 |
VNC_DEBUG("Too short SASL mechname %d\n", mechlen);
|
| 487 |
vnc_client_error(vs); |
| 488 |
return -1; |
| 489 |
} |
| 490 |
vnc_read_when(vs, protocol_client_auth_sasl_mechname,mechlen); |
| 491 |
return 0; |
| 492 |
} |
| 493 |
|
| 494 |
#define USES_X509_AUTH(vs) \
|
| 495 |
((vs)->subauth == VNC_AUTH_VENCRYPT_X509NONE || \ |
| 496 |
(vs)->subauth == VNC_AUTH_VENCRYPT_X509VNC || \ |
| 497 |
(vs)->subauth == VNC_AUTH_VENCRYPT_X509PLAIN || \ |
| 498 |
(vs)->subauth == VNC_AUTH_VENCRYPT_X509SASL) |
| 499 |
|
| 500 |
|
| 501 |
void start_auth_sasl(VncState *vs)
|
| 502 |
{
|
| 503 |
const char *mechlist = NULL; |
| 504 |
sasl_security_properties_t secprops; |
| 505 |
int err;
|
| 506 |
char *localAddr, *remoteAddr;
|
| 507 |
int mechlistlen;
|
| 508 |
|
| 509 |
VNC_DEBUG("Initialize SASL auth %d\n", vs->csock);
|
| 510 |
|
| 511 |
/* Get local & remote client addresses in form IPADDR;PORT */
|
| 512 |
if (!(localAddr = vnc_socket_local_addr("%s;%s", vs->csock))) |
| 513 |
goto authabort;
|
| 514 |
|
| 515 |
if (!(remoteAddr = vnc_socket_remote_addr("%s;%s", vs->csock))) { |
| 516 |
free(localAddr); |
| 517 |
goto authabort;
|
| 518 |
} |
| 519 |
|
| 520 |
err = sasl_server_new("vnc",
|
| 521 |
NULL, /* FQDN - just delegates to gethostname */ |
| 522 |
NULL, /* User realm */ |
| 523 |
localAddr, |
| 524 |
remoteAddr, |
| 525 |
NULL, /* Callbacks, not needed */ |
| 526 |
SASL_SUCCESS_DATA, |
| 527 |
&vs->sasl.conn); |
| 528 |
free(localAddr); |
| 529 |
free(remoteAddr); |
| 530 |
localAddr = remoteAddr = NULL;
|
| 531 |
|
| 532 |
if (err != SASL_OK) {
|
| 533 |
VNC_DEBUG("sasl context setup failed %d (%s)",
|
| 534 |
err, sasl_errstring(err, NULL, NULL)); |
| 535 |
vs->sasl.conn = NULL;
|
| 536 |
goto authabort;
|
| 537 |
} |
| 538 |
|
| 539 |
#ifdef CONFIG_VNC_TLS
|
| 540 |
/* Inform SASL that we've got an external SSF layer from TLS/x509 */
|
| 541 |
if (vs->vd->auth == VNC_AUTH_VENCRYPT &&
|
| 542 |
vs->vd->subauth == VNC_AUTH_VENCRYPT_X509SASL) {
|
| 543 |
gnutls_cipher_algorithm_t cipher; |
| 544 |
sasl_ssf_t ssf; |
| 545 |
|
| 546 |
cipher = gnutls_cipher_get(vs->tls.session); |
| 547 |
if (!(ssf = (sasl_ssf_t)gnutls_cipher_get_key_size(cipher))) {
|
| 548 |
VNC_DEBUG("%s", "cannot TLS get cipher size\n"); |
| 549 |
sasl_dispose(&vs->sasl.conn); |
| 550 |
vs->sasl.conn = NULL;
|
| 551 |
goto authabort;
|
| 552 |
} |
| 553 |
ssf *= 8; /* tls key size is bytes, sasl wants bits */ |
| 554 |
|
| 555 |
err = sasl_setprop(vs->sasl.conn, SASL_SSF_EXTERNAL, &ssf); |
| 556 |
if (err != SASL_OK) {
|
| 557 |
VNC_DEBUG("cannot set SASL external SSF %d (%s)\n",
|
| 558 |
err, sasl_errstring(err, NULL, NULL)); |
| 559 |
sasl_dispose(&vs->sasl.conn); |
| 560 |
vs->sasl.conn = NULL;
|
| 561 |
goto authabort;
|
| 562 |
} |
| 563 |
} else
|
| 564 |
#endif /* CONFIG_VNC_TLS */ |
| 565 |
vs->sasl.wantSSF = 1;
|
| 566 |
|
| 567 |
memset (&secprops, 0, sizeof secprops); |
| 568 |
/* Inform SASL that we've got an external SSF layer from TLS */
|
| 569 |
if (strncmp(vs->vd->display, "unix:", 5) == 0 |
| 570 |
#ifdef CONFIG_VNC_TLS
|
| 571 |
/* Disable SSF, if using TLS+x509+SASL only. TLS without x509
|
| 572 |
is not sufficiently strong */
|
| 573 |
|| (vs->vd->auth == VNC_AUTH_VENCRYPT && |
| 574 |
vs->vd->subauth == VNC_AUTH_VENCRYPT_X509SASL) |
| 575 |
#endif /* CONFIG_VNC_TLS */ |
| 576 |
) {
|
| 577 |
/* If we've got TLS or UNIX domain sock, we don't care about SSF */
|
| 578 |
secprops.min_ssf = 0;
|
| 579 |
secprops.max_ssf = 0;
|
| 580 |
secprops.maxbufsize = 8192;
|
| 581 |
secprops.security_flags = 0;
|
| 582 |
} else {
|
| 583 |
/* Plain TCP, better get an SSF layer */
|
| 584 |
secprops.min_ssf = 56; /* Good enough to require kerberos */ |
| 585 |
secprops.max_ssf = 100000; /* Arbitrary big number */ |
| 586 |
secprops.maxbufsize = 8192;
|
| 587 |
/* Forbid any anonymous or trivially crackable auth */
|
| 588 |
secprops.security_flags = |
| 589 |
SASL_SEC_NOANONYMOUS | SASL_SEC_NOPLAINTEXT; |
| 590 |
} |
| 591 |
|
| 592 |
err = sasl_setprop(vs->sasl.conn, SASL_SEC_PROPS, &secprops); |
| 593 |
if (err != SASL_OK) {
|
| 594 |
VNC_DEBUG("cannot set SASL security props %d (%s)\n",
|
| 595 |
err, sasl_errstring(err, NULL, NULL)); |
| 596 |
sasl_dispose(&vs->sasl.conn); |
| 597 |
vs->sasl.conn = NULL;
|
| 598 |
goto authabort;
|
| 599 |
} |
| 600 |
|
| 601 |
err = sasl_listmech(vs->sasl.conn, |
| 602 |
NULL, /* Don't need to set user */ |
| 603 |
"", /* Prefix */ |
| 604 |
",", /* Separator */ |
| 605 |
"", /* Suffix */ |
| 606 |
&mechlist, |
| 607 |
NULL,
|
| 608 |
NULL);
|
| 609 |
if (err != SASL_OK) {
|
| 610 |
VNC_DEBUG("cannot list SASL mechanisms %d (%s)\n",
|
| 611 |
err, sasl_errdetail(vs->sasl.conn)); |
| 612 |
sasl_dispose(&vs->sasl.conn); |
| 613 |
vs->sasl.conn = NULL;
|
| 614 |
goto authabort;
|
| 615 |
} |
| 616 |
VNC_DEBUG("Available mechanisms for client: '%s'\n", mechlist);
|
| 617 |
|
| 618 |
if (!(vs->sasl.mechlist = strdup(mechlist))) {
|
| 619 |
VNC_DEBUG("Out of memory");
|
| 620 |
sasl_dispose(&vs->sasl.conn); |
| 621 |
vs->sasl.conn = NULL;
|
| 622 |
goto authabort;
|
| 623 |
} |
| 624 |
mechlistlen = strlen(mechlist); |
| 625 |
vnc_write_u32(vs, mechlistlen); |
| 626 |
vnc_write(vs, mechlist, mechlistlen); |
| 627 |
vnc_flush(vs); |
| 628 |
|
| 629 |
VNC_DEBUG("Wait for client mechname length\n");
|
| 630 |
vnc_read_when(vs, protocol_client_auth_sasl_mechname_len, 4);
|
| 631 |
|
| 632 |
return;
|
| 633 |
|
| 634 |
authabort:
|
| 635 |
vnc_client_error(vs); |
| 636 |
return;
|
| 637 |
} |
| 638 |
|
| 639 |
|