dropbear: svr-agentfwd.c annotate

annotate svr-agentfwd.c @ 994:5c5ade336926

Prefer stronger algorithms in algorithm negotiation. Prefer diffie-hellman-group14-sha1 (2048 bit) over diffie-hellman-group1-sha1 (1024 bit). Due to meet-in-the-middle attacks the effective key length of three key 3DES is 112 bits. AES is stronger and faster then 3DES. Prefer to delay the start of compression until after authentication has completed. This avoids exposing compression code to attacks from unauthenticated users. (github pull request #9)

author	Fedor Brunner <fedor.brunner@azet.sk>
date	Fri, 23 Jan 2015 23:00:25 +0800
parents	220f55d540ae
children	7c899f24a85b

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
604 810dfc792ca9 Compile fix for when both client and server agent forwarding is disabled Matt Johnston <matt@ucc.asn.au> parents: 594 diff changeset	30 #ifdef ENABLE_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);
62 20563735e8b5 just checkpointing Matt Johnston <matt@ucc.asn.au> parents: 33 diff changeset	48 static void agentaccept(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 */
108 10f4d3319780 - added circular buffering for channels Matt Johnston <matt@ucc.asn.au> parents: 70 diff changeset	103 static void agentaccept(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
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	120 * just before command/shell execution, after dropping priveleges */
560 52d7301e46bd Agent forwarding works Matt Johnston <matt@ucc.asn.au> parents: 500 diff changeset	121 void svr_agentset(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
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	154 /* 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	155 * for themselves */
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	156 uid = getuid();
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	157 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	158 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	159 (seteuid(ses.authstate.pw_uid)) < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 560 diff changeset	160 dropbear_exit("Failed to set euid");
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	161 }
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	162
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	163 /* 2 for "/" and "\0" */
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	164 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	165
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	166 path = m_malloc(len);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	167 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	168 unlink(path);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	169 m_free(path);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	170
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	171 rmdir(chansess->agentdir);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	172
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	173 if ((seteuid(uid)) < 0 \|\|
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	174 (setegid(gid)) < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 560 diff changeset	175 dropbear_exit("Failed to revert euid");
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	176 }
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	177
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	178 m_free(chansess->agentfile);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	179 m_free(chansess->agentdir);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	180 }
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 }
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	183
225 ca7e76d981d9 - progress towards client agent forwarding Matt Johnston <matt@ucc.asn.au> parents: 165 diff changeset	184 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	185 0, /* sepfds */
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	186 "[email protected]",
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	187 NULL,
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	188 NULL,
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	189 NULL,
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	190 NULL
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	191 };
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	192
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	193
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	194 /* helper for accepting an agent request */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	195 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	196
225 ca7e76d981d9 - progress towards client agent forwarding Matt Johnston <matt@ucc.asn.au> parents: 165 diff changeset	197 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	198 encrypt_packet();
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	199 return DROPBEAR_SUCCESS;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	200 } else {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	201 return DROPBEAR_FAILURE;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	202 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	203 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	204
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	205 /* helper for creating the agent socket-file
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	206 returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	207 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	208
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	209 struct sockaddr_un addr;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	210 unsigned int prefix;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	211 char path[sizeof(addr.sun_path)], sockfile[sizeof(addr.sun_path)];
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	212 mode_t mode;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	213 int i;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	214 uid_t uid;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	215 gid_t gid;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	216 int ret = DROPBEAR_FAILURE;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	217
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	218 /* 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	219 uid = getuid();
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	220 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	221 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	222 (seteuid(ses.authstate.pw_uid)) < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 560 diff changeset	223 dropbear_exit("Failed to set euid");
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	224 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	225
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	226 memset((void*)&addr, 0x0, sizeof(addr));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	227 addr.sun_family = AF_UNIX;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	228
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	229 mode = S_IRWXU;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	230
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	231 for (i = 0; i < 20; i++) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	232 genrandom((unsigned char*)&prefix, sizeof(prefix));
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	233 /* 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	234 snprintf(path, sizeof(path), AGENTDIRPREFIX "%.8x", prefix);
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 if (mkdir(path, mode) == 0) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	237 goto bindsocket;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	238 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	239 if (errno != EEXIST) {
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	240 break;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	241 }
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 /* couldn't make a dir */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	244 goto out;
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 bindsocket:
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	247 /* Format is "/tmp/dropbear-0246dead/auth-d00f7654-23".
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	248 * 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	249 * 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	250 * 1/(2^64) */
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	251 genrandom((unsigned char*)&prefix, sizeof(prefix));
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	252 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	253
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	254 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	255
11 f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	256 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	257 chansess->agentdir = m_strdup(path);
f76c9389e9e0 Mostly done with the listener changeover Matt Johnston <matt@ucc.asn.au> parents: 5 diff changeset	258 chansess->agentfile = m_strdup(sockfile);
4 fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	259 ret = DROPBEAR_SUCCESS;
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	260 }
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	261
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	262
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	263 out:
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	264 if ((seteuid(uid)) < 0 \|\|
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	265 (setegid(gid)) < 0) {
594 a98a2138364a Improve capitalisation for all logged strings Matt Johnston <matt@ucc.asn.au> parents: 560 diff changeset	266 dropbear_exit("Failed to revert euid");
4 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 return ret;
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
fe6bca95afa7 Makefile.in contains updated files required Matt Johnston <matt@ucc.asn.au> parents: diff changeset	271 #endif

Mercurial > dropbear

annotate svr-agentfwd.c @ 994:5c5ade336926