dropbear: svr-agentfwd.c annotate

annotate svr-agentfwd.c @ 1788:1fc0012b9c38

Fix handling of replies to global requests (#112) The current code assumes that all global requests want / need a reply. This isn't always true and the request itself indicates if it wants a reply or not. It causes a specific problem with [email protected] messages. These are sent by OpenSSH after authentication to inform the client of potential other host keys for the host. This can be used to add a new type of host key or to rotate host keys. The initial information message from the server is sent as a global request, but with want_reply set to false. This means that the server doesn't expect an answer to this message. Instead the client needs to send a prove request as a reply if it wants to receive proof of ownership for the host keys. The bug doesn't cause any current problems with due to how OpenSSH treats receiving the failure message. It instead treats it as a keepalive message and further ignores it. Arguably this is a protocol violation though of Dropbear and it is only accidental that it doesn't cause a problem with OpenSSH. The bug was found when adding host keys support to libssh, which is more strict protocol wise and treats the unexpected failure message an error, also see https://gitlab.com/libssh/libssh-mirror/-/merge_requests/145 for more information. The fix here is to honor the want_reply flag in the global request and to only send a reply if the other side expects a reply.

author	Dirkjan Bussink <d.bussink@gmail.com>
date	Thu, 10 Dec 2020 16:13:13 +0100
parents	592a18dac250
children	a7cc3332d8ab

rev	line source
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	1 /*
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	2 * Dropbear - a SSH2 server
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	3 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	4 * Copyright (c) 2002,2003 Matt Johnston
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	5 * All rights reserved.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	6 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	7 * Permission is hereby granted, free of charge, to any person obtaining a copy
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	8 * of this software and associated documentation files (the "Software"), to deal
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	9 * in the Software without restriction, including without limitation the rights
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	11 * copies of the Software, and to permit persons to whom the Software is
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	12 * furnished to do so, subject to the following conditions:
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	13 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	14 * The above copyright notice and this permission notice shall be included in
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	15 * all copies or substantial portions of the Software.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	16 *
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	23 * SOFTWARE. */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	24
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	25 /* This file (agentfwd.c) handles authentication agent forwarding, for OpenSSH
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	26 * style agents. */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	27
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	28 #include "includes.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	29
1295 750ec4ec4cbe Convert #ifdef to #if, other build changes Matt Johnston <matt@ucc.asn.au> parents: 1037 diff changeset	30 #if DROPBEAR_SVR_AGENTFWD
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	31
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	32 #include "agentfwd.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	33 #include "session.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	34 #include "ssh.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	35 #include "dbutil.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	36 #include "chansession.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	37 #include "channel.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	38 #include "packet.h"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	39 #include "buffer.h"
858 220f55d540ae rename random.h to dbrandom.h since some OSes have a system random.h Matt Johnston <matt@ucc.asn.au> parents: 617 diff changeset	40 #include "dbrandom.h"
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	41 #include "listener.h"
475 52a644e7b8e1 * Patch from Frédéric Moulins adding options to authorized_keys. Matt Johnston <matt@ucc.asn.au> parents: 464 diff changeset	42 #include "auth.h"
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	43
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	44 #define AGENTDIRPREFIX "/tmp/dropbear-"
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	45
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	46 static int send_msg_channel_open_agent(int fd);
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	47 static int bindagent(int fd, struct ChanSess * chansess);
1460 58a74cb829b8 Pointer parameter could be declared as pointing to const (callback) Francois Perrad <francois.perrad@gadz.org> parents: 1459 diff changeset	48 static void agentaccept(const struct Listener * listener, int sock);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	49
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	50 /* Handles client requests to start agent forwarding, sets up listening socket.
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	51 * Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
560 52d7301e46bd Agent forwarding works Matt Johnston <matt@ucc.asn.au> parents: 500 diff changeset	52 int svr_agentreq(struct ChanSess * chansess) {
617 81def6b732c7 Clean up fd on failure. Found by Klocwork Matt Johnston <matt@ucc.asn.au> parents: 604 diff changeset	53 int fd = -1;
560 52d7301e46bd Agent forwarding works Matt Johnston <matt@ucc.asn.au> parents: 500 diff changeset	54
475 52a644e7b8e1 * Patch from Frédéric Moulins adding options to authorized_keys. Matt Johnston <matt@ucc.asn.au> parents: 464 diff changeset	55 if (!svr_pubkey_allows_agentfwd()) {
52a644e7b8e1 * Patch from Frédéric Moulins adding options to authorized_keys. Matt Johnston <matt@ucc.asn.au> parents: 464 diff changeset	56 return DROPBEAR_FAILURE;
52a644e7b8e1 * Patch from Frédéric Moulins adding options to authorized_keys. Matt Johnston <matt@ucc.asn.au> parents: 464 diff changeset	57 }
52a644e7b8e1 * Patch from Frédéric Moulins adding options to authorized_keys. Matt Johnston <matt@ucc.asn.au> parents: 464 diff changeset	58
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	59 if (chansess->agentlistener != NULL) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	60 return DROPBEAR_FAILURE;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	61 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	62
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	63 /* create listening socket */
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	64 fd = socket(PF_UNIX, SOCK_STREAM, 0);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	65 if (fd < 0) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	66 goto fail;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	67 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	68
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	69 /* create the unix socket dir and file */
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	70 if (bindagent(fd, chansess) == DROPBEAR_FAILURE) {
70 b0316ce64e4b Merging in the changes from 0.41-0.43 main Dropbear tree Matt Johnston <matt@ucc.asn.au> parents: 62 diff changeset	71 goto fail;
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	72 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	73
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	74 /* listen */
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	75 if (listen(fd, 20) < 0) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	76 goto fail;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	77 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	78
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	79 /* set non-blocking */
109 2e9d1f29c50f merge of 50be59810e462f9f44f55e421227d6aa0b31982b Matt Johnston <matt@ucc.asn.au> parents: 108 diff changeset	80 setnonblocking(fd);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	81
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	82 /* pass if off to listener */
62 20563735e8b5 just checkpointing Matt Johnston <matt@ucc.asn.au> parents: 33 diff changeset	83 chansess->agentlistener = new_listener( &fd, 1, 0, chansess,
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	84 agentaccept, NULL);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	85
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	86 if (chansess->agentlistener == NULL) {
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	87 goto fail;
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	88 }
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	89
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	90 return DROPBEAR_SUCCESS;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	91
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	92 fail:
617 81def6b732c7 Clean up fd on failure. Found by Klocwork Matt Johnston <matt@ucc.asn.au> parents: 604 diff changeset	93 m_close(fd);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	94 /* cleanup */
560 52d7301e46bd Agent forwarding works Matt Johnston <matt@ucc.asn.au> parents: 500 diff changeset	95 svr_agentcleanup(chansess);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	96
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	97 return DROPBEAR_FAILURE;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	98 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	99
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	100 /* accepts a connection on the forwarded socket and opens a new channel for it
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	101 * back to the client */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	102 /* returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
1460 58a74cb829b8 Pointer parameter could be declared as pointing to const (callback) Francois Perrad <francois.perrad@gadz.org> parents: 1459 diff changeset	103 static void agentaccept(const struct Listener *UNUSED(listener), int sock) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	104
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	105 int fd;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	106
62 20563735e8b5 just checkpointing Matt Johnston <matt@ucc.asn.au> parents: 33 diff changeset	107 fd = accept(sock, NULL, NULL);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	108 if (fd < 0) {
165 0cfba3034be5 Fixed DEBUG_TRACE macro so that we don't get semicolons left about the place Matt Johnston <matt@ucc.asn.au> parents: 109 diff changeset	109 TRACE(("accept failed"))
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	110 return;
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	111 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	112
13 db2c8e6fb284 Fixed stupid agentfwd error (using the listening FD, not the accepted on. gah) Matt Johnston <matt@ucc.asn.au> parents: 11 diff changeset	113 if (send_msg_channel_open_agent(fd) != DROPBEAR_SUCCESS) {
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	114 close(fd);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	115 }
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	116
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	117 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	118
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	119 /* set up the environment variable pointing to the socket. This is called
1037 7c899f24a85b Some minor typo fixes, found by codespell. Thorsten Horstmann <thorsten.horstmann@web.de> parents: 858 diff changeset	120 * just before command/shell execution, after dropping privileges */
1459 06d52bcb8094 Pointer parameter could be declared as pointing to const Francois Perrad <francois.perrad@gadz.org> parents: 1295 diff changeset	121 void svr_agentset(const struct ChanSess * chansess) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	122
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	123 char *path = NULL;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	124 int len;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	125
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	126 if (chansess->agentlistener == NULL) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	127 return;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	128 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	129
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	130 /* 2 for "/" and "\0" */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	131 len = strlen(chansess->agentdir) + strlen(chansess->agentfile) + 2;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	132
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	133 path = m_malloc(len);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	134 snprintf(path, len, "%s/%s", chansess->agentdir, chansess->agentfile);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	135 addnewvar("SSH_AUTH_SOCK", path);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	136 m_free(path);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	137 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	138
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	139 /* close the socket, remove the socket-file */
560 52d7301e46bd Agent forwarding works Matt Johnston <matt@ucc.asn.au> parents: 500 diff changeset	140 void svr_agentcleanup(struct ChanSess * chansess) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	141
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	142 char *path = NULL;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	143 uid_t uid;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	144 gid_t gid;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	145 int len;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	146
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	147 if (chansess->agentlistener != NULL) {
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	148 remove_listener(chansess->agentlistener);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	149 chansess->agentlistener = NULL;
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	150 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	151
70 b0316ce64e4b Merging in the changes from 0.41-0.43 main Dropbear tree Matt Johnston <matt@ucc.asn.au> parents: 62 diff changeset	152 if (chansess->agentfile != NULL && chansess->agentdir != NULL) {
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	153
1633 592a18dac250 Support servers without multiple user support (#76) Patrick Stewart <patstew@gmail.com> parents: 1631 diff changeset	154 #if DROPBEAR_SVR_MULTIUSER
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	155 /* Remove the dir as the user. That way they can't cause problems except
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	156 * for themselves */
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	157 uid = getuid();
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	158 gid = getgid();
464 4317be8b7cf9 Make a copy of passwd fields since getpwnam()'s retval isn't safe to keep Matt Johnston <matt@ucc.asn.au> parents: 165 diff changeset	159 if ((setegid(ses.authstate.pw_gid)) < 0 \|\|
4317be8b7cf9 Make a copy of passwd fields since getpwnam()'s retval isn't safe to keep Matt Johnston <matt@ucc.asn.au> parents: 165 diff changeset	160 (seteuid(ses.authstate.pw_uid)) < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 560 diff changeset	161 dropbear_exit("Failed to set euid");
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	162 }
1633 592a18dac250 Support servers without multiple user support (#76) Patrick Stewart <patstew@gmail.com> parents: 1631 diff changeset	163 #endif
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	164
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	165 /* 2 for "/" and "\0" */
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	166 len = strlen(chansess->agentdir) + strlen(chansess->agentfile) + 2;
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	167
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	168 path = m_malloc(len);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	169 snprintf(path, len, "%s/%s", chansess->agentdir, chansess->agentfile);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	170 unlink(path);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	171 m_free(path);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	172
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	173 rmdir(chansess->agentdir);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	174
1633 592a18dac250 Support servers without multiple user support (#76) Patrick Stewart <patstew@gmail.com> parents: 1631 diff changeset	175 #if DROPBEAR_SVR_MULTIUSER
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	176 if ((seteuid(uid)) < 0 \|\|
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	177 (setegid(gid)) < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 560 diff changeset	178 dropbear_exit("Failed to revert euid");
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	179 }
1633 592a18dac250 Support servers without multiple user support (#76) Patrick Stewart <patstew@gmail.com> parents: 1631 diff changeset	180 #endif
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	181
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	182 m_free(chansess->agentfile);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	183 m_free(chansess->agentdir);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	184 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	185
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	186 }
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	187
225 ca7e76d981d9 - progress towards client agent forwarding Matt Johnston <matt@ucc.asn.au> parents: 165 diff changeset	188 static const struct ChanType chan_svr_agent = {
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	189 0, /* sepfds */
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	190 "[email protected]",
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	191 NULL,
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	192 NULL,
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	193 NULL,
1625 79eef94ccea9 Split ChanType closehandler() and cleanup() so that dbclient doesn't Matt Johnston <matt@ucc.asn.au> parents: 1460 diff changeset	194 NULL,
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	195 NULL
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	196 };
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	197
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	198
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	199 /* helper for accepting an agent request */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	200 static int send_msg_channel_open_agent(int fd) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	201
225 ca7e76d981d9 - progress towards client agent forwarding Matt Johnston <matt@ucc.asn.au> parents: 165 diff changeset	202 if (send_msg_channel_open_init(fd, &chan_svr_agent) == DROPBEAR_SUCCESS) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	203 encrypt_packet();
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	204 return DROPBEAR_SUCCESS;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	205 } else {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	206 return DROPBEAR_FAILURE;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	207 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	208 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	209
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	210 /* helper for creating the agent socket-file
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	211 returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	212 static int bindagent(int fd, struct ChanSess * chansess) {
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	213
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	214 struct sockaddr_un addr;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	215 unsigned int prefix;
1631 292f79307600 fix some gcc warnings (#73) François Perrad <francois.perrad@gadz.org> parents: 1625 diff changeset	216 char path[(sizeof(addr.sun_path)-1)/2], sockfile[(sizeof(addr.sun_path)-1)/2];
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	217 mode_t mode;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	218 int i;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	219 uid_t uid;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	220 gid_t gid;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	221 int ret = DROPBEAR_FAILURE;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	222
1633 592a18dac250 Support servers without multiple user support (#76) Patrick Stewart <patstew@gmail.com> parents: 1631 diff changeset	223 #if DROPBEAR_SVR_MULTIUSER
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	224 /* drop to user privs to make the dir/file */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	225 uid = getuid();
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	226 gid = getgid();
464 4317be8b7cf9 Make a copy of passwd fields since getpwnam()'s retval isn't safe to keep Matt Johnston <matt@ucc.asn.au> parents: 165 diff changeset	227 if ((setegid(ses.authstate.pw_gid)) < 0 \|\|
4317be8b7cf9 Make a copy of passwd fields since getpwnam()'s retval isn't safe to keep Matt Johnston <matt@ucc.asn.au> parents: 165 diff changeset	228 (seteuid(ses.authstate.pw_uid)) < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 560 diff changeset	229 dropbear_exit("Failed to set euid");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	230 }
1633 592a18dac250 Support servers without multiple user support (#76) Patrick Stewart <patstew@gmail.com> parents: 1631 diff changeset	231 #endif
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	232
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	233 memset((void*)&addr, 0x0, sizeof(addr));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	234 addr.sun_family = AF_UNIX;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	235
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	236 mode = S_IRWXU;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	237
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	238 for (i = 0; i < 20; i++) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	239 genrandom((unsigned char*)&prefix, sizeof(prefix));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	240 /* we want 32 bits (8 hex digits) - "/tmp/dropbear-f19c62c0" */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	241 snprintf(path, sizeof(path), AGENTDIRPREFIX "%.8x", prefix);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	242
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	243 if (mkdir(path, mode) == 0) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	244 goto bindsocket;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	245 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	246 if (errno != EEXIST) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	247 break;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	248 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	249 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	250 /* couldn't make a dir */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	251 goto out;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	252
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	253 bindsocket:
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	254 /* Format is "/tmp/dropbear-0246dead/auth-d00f7654-23".
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	255 * The "23" is the file desc, the random data is to avoid collisions
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	256 * between subsequent user processes reusing socket fds (odds are now
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	257 * 1/(2^64) */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	258 genrandom((unsigned char*)&prefix, sizeof(prefix));
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	259 snprintf(sockfile, sizeof(sockfile), "auth-%.8x-%d", prefix, fd);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	260
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	261 snprintf(addr.sun_path, sizeof(addr.sun_path), "%s/%s", path, sockfile);
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	262
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	263 if (bind(fd, (struct sockaddr*)&addr, sizeof(addr)) == 0) {
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	264 chansess->agentdir = m_strdup(path);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	265 chansess->agentfile = m_strdup(sockfile);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	266 ret = DROPBEAR_SUCCESS;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	267 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	268
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	269
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	270 out:
1633 592a18dac250 Support servers without multiple user support (#76) Patrick Stewart <patstew@gmail.com> parents: 1631 diff changeset	271 #if DROPBEAR_SVR_MULTIUSER
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	272 if ((seteuid(uid)) < 0 \|\|
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	273 (setegid(gid)) < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 560 diff changeset	274 dropbear_exit("Failed to revert euid");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	275 }
1633 592a18dac250 Support servers without multiple user support (#76) Patrick Stewart <patstew@gmail.com> parents: 1631 diff changeset	276 #endif
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	277 return ret;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	278 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	279
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	280 #endif

Mercurial > dropbear

annotate svr-agentfwd.c @ 1788:1fc0012b9c38