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merge of abac2150ee4f4031a98016241fbd136d24fed127

Browse Source 
and ffa047425729e478a5b49b1ab0f8ec71c08a1421

--HG--
extra : convert_revision : e9b7d4eda64d70aff736f48cc8dea680b153139b
This commit is contained in:
Matt Johnston 2004-06-23 07:14:16 +00:00
commit 09b50641ff
14 changed files with 231 additions and 232 deletions
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4
common-kex.c
View File

@ -450,8 +450,8 @@ void recv_msg_kexinit() {
/* the rest of ses.kexhashbuf will be done after DH exchange */
ses.kexstate.recvkexinit = 1;
// ses.expecting = SSH_MSG_KEXDH_INIT;
ses.expecting = 0;
ses.requirenext = SSH_MSG_KEXDH_INIT;
// ses.expecting = 0; // client matt
TRACE(("leave recv_msg_kexinit"));
}

15
common-packet.c
View File

@ -402,21 +402,6 @@ static buffer* buf_decompress(buffer* buf, unsigned int len) {
/* This must be called directly after receiving the unimplemented packet.
* Isn't the most clean implementation, it relies on packet processing
* occurring directly after decryption. This is reasonably valid, since
* there is only a single decryption buffer */
void recv_unimplemented() {
CHECKCLEARTOWRITE();
buf_putbyte(ses.writepayload, SSH_MSG_UNIMPLEMENTED);
/* the decryption routine increments the sequence number, we must
* decrement */
buf_putint(ses.writepayload, ses.recvseq - 1);
encrypt_packet();
}
/* encrypt the writepayload, putting into writebuf, ready for write_packet()
* to put on the wire */

6
common-session.c
View File

@ -76,7 +76,7 @@ void common_session_init(int sock, runopts *opts) {
ses.payload = NULL;
ses.recvseq = 0;
ses.expecting = SSH_MSG_KEXINIT;
ses.requirenext = SSH_MSG_KEXINIT;
ses.dataallowed = 0; /* don't send data yet, we'll wait until after kex */
ses.ignorenext = 0;
@ -106,8 +106,12 @@ void common_session_init(int sock, runopts *opts) {
ses.dh_K = NULL;
ses.remoteident = NULL;
ses.authdone = 0;
ses.chantypes = NULL;
ses.allowprivport = 0;
TRACE(("leave session_init"));
}

2
debug.h
View File

@ -36,7 +36,7 @@
/* Define this to print trace statements - very verbose */
/* Caution: Don't use this in an unfriendly environment (ie unfirewalled),
* since the printing does not sanitise strings etc */
/*#define DEBUG_TRACE*/
#define DEBUG_TRACE
/* All functions writing to the cleartext payload buffer call
* CHECKCLEARTOWRITE() before writing. This is only really useful if you're

8
packet.h
View File

@ -32,9 +32,13 @@ void write_packet();
void read_packet();
void decrypt_packet();
void encrypt_packet();
void recv_unimplemented();
void svr_process_packet();
void process_packet();
typedef struct PacketType {
unsigned char type; /* SSH_MSG_FOO */
void (*handler)();
} packettype;
#define PACKET_PADDING_OFF 4
#define PACKET_PAYLOAD_OFF 5

161
process-packet.c Normal file
View File

@ -0,0 +1,161 @@
/*
* Dropbear - a SSH2 server
*
* Copyright (c) 2002-2004 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
#include "includes.h"
#include "packet.h"
#include "session.h"
#include "dbutil.h"
#include "ssh.h"
#include "algo.h"
#include "buffer.h"
#include "kex.h"
#include "random.h"
#include "service.h"
#include "auth.h"
#include "channel.h"
#define MAX_UNAUTH_PACKET_TYPE SSH_MSG_USERAUTH_PK_OK
static void recv_unimplemented();
/* process a decrypted packet, call the appropriate handler */
void process_packet() {
unsigned char type;
unsigned int i;
TRACE(("enter process_packet"));
type = buf_getbyte(ses.payload);
TRACE(("process_packet: packet type = %d", type));
/* These packets we can receive at any time */
switch(type) {
case SSH_MSG_IGNORE:
case SSH_MSG_DEBUG:
TRACE(("received SSH_MSG_IGNORE or SSH_MSG_DEBUG"));
goto out;
case SSH_MSG_UNIMPLEMENTED:
/* debugging XXX */
TRACE(("SSH_MSG_UNIMPLEMENTED"));
dropbear_exit("received SSH_MSG_UNIMPLEMENTED");
case SSH_MSG_DISCONNECT:
/* TODO cleanup? */
dropbear_close("Disconnect received");
}
/* This applies for KEX, where the spec says the next packet MUST be
* NEWKEYS */
if (ses.requirenext != 0) {
if (ses.requirenext != type) {
/* TODO send disconnect? */
dropbear_exit("unexpected packet type %d, expected %d", type,
ses.requirenext);
} else {
/* Got what we expected */
ses.requirenext = 0;
}
}
/* Check if we should ignore this packet. Used currently only for
* KEX code, with first_kex_packet_follows */
if (ses.ignorenext) {
TRACE(("Ignoring packet, type = %d", type));
ses.ignorenext = 0;
goto out;
}
/* XXX This code somewhere else perhaps? */
#ifdef DROPBEAR_CLIENT
if (IS_DROPBEAR_CLIENT) {
/* XXX - needs changing */
/* In client mode, we REUSE ses.expecting to proceed to the
* next phase when a packet was received.
* If the "expecting" flag is set to a non-null value, it will
* be reset when a packet of that type is received.
* This is different from the server-mode behaviour, when
* a packet type mismatch would have caused sudden death.
*/
/* check that we aren't expecting a particular packet */
if (cli_ses.expecting && cli_ses.expecting == type) {
cli_ses.expecting = 0;
}
}
#endif
/* Kindly the protocol authors gave all the preauth packets type values
* less-than-or-equal-to 60 ( == MAX_UNAUTH_PACKET_TYPE ).
* NOTE: if the protocol changes and new types are added, revisit this
* assumption */
if ( !ses.authdone && type > MAX_UNAUTH_PACKET_TYPE ) {
dropbear_exit("received message %d before userauth", type);
}
for (i = 0; ; i++) {
if (ses.packettypes[i].type == 0) {
/* end of list */
break;
}
if (ses.packettypes[i].type == type) {
ses.packettypes[i].handler();
goto out;
}
}
/* TODO do something more here? */
TRACE(("preauth unknown packet"));
recv_unimplemented();
out:
buf_free(ses.payload);
ses.payload = NULL;
TRACE(("leave process_packet"));
}
/* This must be called directly after receiving the unimplemented packet.
* Isn't the most clean implementation, it relies on packet processing
* occurring directly after decryption (direct use of ses.recvseq).
* This is reasonably valid, since there is only a single decryption buffer */
static void recv_unimplemented() {
CHECKCLEARTOWRITE();
buf_putbyte(ses.writepayload, SSH_MSG_UNIMPLEMENTED);
/* the decryption routine increments the sequence number, we must
* decrement */
buf_putint(ses.writepayload, ses.recvseq - 1);
encrypt_packet();
}

17
session.h
View File

@ -34,6 +34,7 @@
#include "queue.h"
#include "runopts.h"
#include "listener.h"
#include "packet.h"
extern int sessinitdone; /* Is set to 0 somewhere */
extern int exitflag;
@ -106,10 +107,13 @@ struct sshsession {
unsigned int transseq, recvseq; /* Sequence IDs */
/* Packet-handling flags */
const packettype * packettypes; /* Packet handler mappings for this
session, see process-packet.c */
unsigned dataallowed : 1; /* whether we can send data packets or we are in
the middle of a KEX or something */
unsigned char expecting; /* byte indicating what packet we expect next,
unsigned char requirenext; /* byte indicating what packet we require next,
or 0x00 for any */
unsigned char ignorenext; /* whether to ignore the next packet,
@ -130,6 +134,12 @@ struct sshsession {
can add it to the hash when generating keys */
unsigned char authdone; /* Indicates when authentication has been
completed. This applies to both client and
server - in the server it gets set to 1 when
authentication is successful, in the client it
is set when the server has told us that auth
succeeded */
/* Channel related */
struct Channel ** channels; /* these pointers may be null */
@ -138,10 +148,13 @@ struct sshsession {
/* TCP forwarding - where manage listeners */
#ifndef DISABLE_REMOTETCPFWD
#ifdef USING_LISTENERS
struct Listener ** listeners;
unsigned int listensize;
/* Whether to allow binding to privileged ports (<1024). This doesn't
* really belong here, but nowhere else fits nicely */
#endif
int allowprivport;
};

3
ssh.h
View File

@ -44,6 +44,9 @@
#define SSH_MSG_USERAUTH_BANNER 53
#define SSH_MSG_USERAUTH_PK_OK 60
/* If adding numbers here, check MAX_UNAUTH_PACKET_TYPE in process-packet.c
* is still valid */
/* connect message numbers */
#define SSH_MSG_GLOBAL_REQUEST 80
#define SSH_MSG_REQUEST_SUCCESS 81

10
svr-auth.c
View File

@ -52,7 +52,7 @@ void authinitialise() {
* on initialisation */
static void authclear() {
svr_ses.authstate.authdone = 0;
ses.authdone = 0;
svr_ses.authstate.pw = NULL;
svr_ses.authstate.username = NULL;
svr_ses.authstate.printableuser = NULL;
@ -102,7 +102,7 @@ void recv_msg_userauth_request() {
TRACE(("enter recv_msg_userauth_request"));
/* ignore packets if auth is already done */
if (svr_ses.authstate.authdone == 1) {
if (ses.authdone == 1) {
return;
}
@ -339,7 +339,11 @@ void send_msg_userauth_success() {
buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_SUCCESS);
encrypt_packet();
svr_ses.authstate.authdone = 1;
ses.authdone = 1;
if (svr_ses.authstate.pw->pw_uid == 0) {
ses.allowprivport = 1;
}
/* Remove from the list of pre-auth sockets. Should be m_close(), since if
* we fail, we might end up leaking connection slots, and disallow new

2
svr-kex.c
View File

@ -57,7 +57,7 @@ void recv_msg_kexdh_init() {
mp_clear(&dh_e);
send_msg_newkeys();
ses.expecting = SSH_MSG_NEWKEYS;
ses.requirenext = SSH_MSG_NEWKEYS;
TRACE(("leave recv_msg_kexdh_init"));
}

196
svr-packet.c
View File

@ -1,196 +0,0 @@
/*
* Dropbear - a SSH2 server
*
* Copyright (c) 2002,2003 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
#include "includes.h"
#include "packet.h"
#include "session.h"
#include "dbutil.h"
#include "ssh.h"
#include "algo.h"
#include "buffer.h"
#include "kex.h"
#include "random.h"
#include "service.h"
#include "auth.h"
#include "channel.h"
static void svr_process_postauth_packet(unsigned int type);
/* process a decrypted packet, call the appropriate handler */
void svr_process_packet() {
unsigned char type;
TRACE(("enter process_packet"));
type = buf_getbyte(ses.payload);
TRACE(("process_packet: packet type = %d", type));
/* these packets we can receive at any time, regardless of expecting
* other packets: */
switch(type) {
case SSH_MSG_IGNORE:
case SSH_MSG_DEBUG:
TRACE(("received SSH_MSG_IGNORE or SSH_MSG_DEBUG"));
goto out;
case SSH_MSG_UNIMPLEMENTED:
/* debugging XXX */
TRACE(("SSH_MSG_UNIMPLEMENTED"));
dropbear_exit("received SSH_MSG_UNIMPLEMENTED");
case SSH_MSG_DISCONNECT:
/* TODO cleanup? */
dropbear_close("Disconnect received");
}
/* Check if we should ignore this packet. Used currently only for
* KEX code, with first_kex_packet_follows */
if (ses.ignorenext) {
TRACE(("Ignoring packet, type = %d", type));
ses.ignorenext = 0;
goto out;
}
/* check that we aren't expecting a particular packet */
if (ses.expecting && ses.expecting != type) {
/* TODO send disconnect? */
dropbear_exit("unexpected packet type %d, expected %d", type,
ses.expecting);
}
/* handle the packet depending on type */
ses.expecting = 0;
switch (type) {
case SSH_MSG_SERVICE_REQUEST:
recv_msg_service_request();
break;
case SSH_MSG_USERAUTH_REQUEST:
recv_msg_userauth_request();
break;
case SSH_MSG_KEXINIT:
recv_msg_kexinit();
break;
case SSH_MSG_KEXDH_INIT:
recv_msg_kexdh_init();
break;
case SSH_MSG_NEWKEYS:
recv_msg_newkeys();
break;
/* this is ugly, need to make a cleaner way to do it */
case SSH_MSG_CHANNEL_DATA:
case SSH_MSG_CHANNEL_WINDOW_ADJUST:
case SSH_MSG_CHANNEL_REQUEST:
case SSH_MSG_CHANNEL_OPEN:
case SSH_MSG_CHANNEL_EOF:
case SSH_MSG_CHANNEL_CLOSE:
case SSH_MSG_CHANNEL_OPEN_CONFIRMATION:
case SSH_MSG_CHANNEL_OPEN_FAILURE:
case SSH_MSG_GLOBAL_REQUEST:
/* these should be checked for authdone below */
svr_process_postauth_packet(type);
break;
default:
/* TODO this possibly should be handled */
TRACE(("preauth unknown packet"));
recv_unimplemented();
break;
}
out:
buf_free(ses.payload);
ses.payload = NULL;
TRACE(("leave process_packet"));
}
/* process a packet, and also check that auth has been done */
static void svr_process_postauth_packet(unsigned int type) {
/* messages following here require userauth before use */
/* IF YOU ADD MORE PACKET TYPES, MAKE SURE THEY'RE ALSO ADDED TO THE LIST
* IN process_packet() XXX XXX XXX */
if (!svr_ses.authstate.authdone) {
dropbear_exit("received message %d before userauth", type);
}
switch (type) {
case SSH_MSG_CHANNEL_DATA:
recv_msg_channel_data();
break;
case SSH_MSG_CHANNEL_WINDOW_ADJUST:
recv_msg_channel_window_adjust();
break;
#ifndef DISABLE_REMOTETCPFWD
case SSH_MSG_GLOBAL_REQUEST:
/* currently only used for remote tcp, so we cheat a little */
recv_msg_global_request_remotetcp();
break;
#endif
case SSH_MSG_CHANNEL_REQUEST:
recv_msg_channel_request();
break;
case SSH_MSG_CHANNEL_OPEN:
recv_msg_channel_open();
break;
case SSH_MSG_CHANNEL_EOF:
recv_msg_channel_eof();
break;
case SSH_MSG_CHANNEL_CLOSE:
recv_msg_channel_close();
break;
#ifdef USING_LISTENERS /* for x11, tcp fwd etc */
case SSH_MSG_CHANNEL_OPEN_CONFIRMATION:
recv_msg_channel_open_confirmation();
break;
case SSH_MSG_CHANNEL_OPEN_FAILURE:
recv_msg_channel_open_failure();
break;
#endif
default:
TRACE(("unknown packet()"));
recv_unimplemented();
break;
}
}

2
svr-service.c
View File

@ -56,7 +56,7 @@ void recv_msg_service_request() {
/* ssh-connection */
if (len == SSH_SERVICE_CONNECTION_LEN &&
(strncmp(SSH_SERVICE_CONNECTION, name, len) == 0)) {
if (svr_ses.authstate.authdone != 1) {
if (ses.authdone != 1) {
dropbear_exit("request for connection before auth");
}

32
svr-session.c
View File

@ -36,18 +36,39 @@
#include "chansession.h"
#include "atomicio.h"
#include "tcpfwd-direct.h"
#include "service.h"
#include "auth.h"
#include "tcpfwd-remote.h"
static void svr_remoteclosed();
struct serversession svr_ses;
const struct ChanType *chantypes[] = {
static const packettype svr_packettypes[] = {
/* TYPE, AUTHREQUIRED, FUNCTION */
{SSH_MSG_SERVICE_REQUEST, recv_msg_service_request}, // server
{SSH_MSG_USERAUTH_REQUEST, recv_msg_userauth_request}, //server
{SSH_MSG_KEXINIT, recv_msg_kexinit},
{SSH_MSG_KEXDH_INIT, recv_msg_kexdh_init},
{SSH_MSG_NEWKEYS, recv_msg_newkeys},
{SSH_MSG_CHANNEL_DATA, recv_msg_channel_data},
{SSH_MSG_CHANNEL_WINDOW_ADJUST, recv_msg_channel_window_adjust},
{SSH_MSG_GLOBAL_REQUEST, recv_msg_global_request_remotetcp},
{SSH_MSG_CHANNEL_REQUEST, recv_msg_channel_request},
{SSH_MSG_CHANNEL_OPEN, recv_msg_channel_open},
{SSH_MSG_CHANNEL_EOF, recv_msg_channel_eof},
{SSH_MSG_CHANNEL_CLOSE, recv_msg_channel_close},
{SSH_MSG_CHANNEL_OPEN_CONFIRMATION, recv_msg_channel_open_confirmation},
{SSH_MSG_CHANNEL_OPEN_FAILURE, recv_msg_channel_open_failure},
{0, 0} /* End */
};
static const struct ChanType *svr_chantypes[] = {
&svrchansess,
&chan_tcpdirect,
NULL /* Null termination is mandatory. */
};
void svr_session(int sock, runopts *opts, int childpipe,
struct sockaddr* remoteaddr) {
@ -64,7 +85,7 @@ void svr_session(int sock, runopts *opts, int childpipe,
/* Initialise server specific parts of the session */
svr_ses.childpipe = childpipe;
authinitialise();
chaninitialise(chantypes);
chaninitialise(svr_chantypes);
svr_chansessinitialise();
if (gettimeofday(&timeout, 0) < 0) {
@ -76,6 +97,9 @@ void svr_session(int sock, runopts *opts, int childpipe,
/* set up messages etc */
session_remoteclosed = svr_remoteclosed;
/* packet handlers */
ses.packettypes = svr_packettypes;
/* We're ready to go now */
sessinitdone = 1;
@ -145,7 +169,7 @@ void svr_session(int sock, runopts *opts, int childpipe,
/* Process the decrypted packet. After this, the read buffer
* will be ready for a new packet */
if (ses.payload != NULL) {
svr_process_packet();
process_packet();
}
}

5
tcpfwd-remote.c
View File

@ -208,13 +208,10 @@ static int remotetcpreq() {
goto out;
}
/* XXX matt - server change
if (ses.authstate.pw->pw_uid != 0
&& port < IPPORT_RESERVED) {
if (!ses.allowprivport && port < IPPORT_RESERVED) {
TRACE(("can't assign port < 1024 for non-root"));
goto out;
}
*/
ret = listen_tcpfwd(bindaddr, port);