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upstream: Add a PermitListen directive to control which server-side

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addresses may be listened on when the client requests remote forwarding (ssh
-R).

This is the converse of the existing PermitOpen directive and this
includes some refactoring to share much of its implementation.

feedback and ok markus@

OpenBSD-Commit-ID: 15a931238c61a3f2ac74ea18a98c933e358e277f
This commit is contained in:
djm@openbsd.org 2018-06-06 18:22:41 +00:00 committed by Damien Miller
parent 7703ae5f5d
commit 115063a664
7 changed files with 453 additions and 271 deletions
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475
channels.c
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@ -1,4 +1,4 @@
/* $OpenBSD: channels.c,v 1.380 2018/04/10 00:10:49 djm Exp $ */ /* $OpenBSD: channels.c,v 1.381 2018/06/06 18:22:41 djm Exp $ */
/* /*
* Author: Tatu Ylonen <ylo@cs.hut.fi> * Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -82,6 +82,7 @@
#include "key.h" #include "key.h"
#include "authfd.h" #include "authfd.h"
#include "pathnames.h" #include "pathnames.h"
#include "match.h"
/* -- agent forwarding */ /* -- agent forwarding */
#define NUM_SOCKS 10 #define NUM_SOCKS 10
@ -97,6 +98,10 @@
/* Maximum number of fake X11 displays to try. */ /* Maximum number of fake X11 displays to try. */
#define MAX_DISPLAYS 1000 #define MAX_DISPLAYS 1000
/* Per-channel callback for pre/post select() actions */
typedef void chan_fn(struct ssh *, Channel *c,
fd_set *readset, fd_set *writeset);
/* /*
* Data structure for storing which hosts are permitted for forward requests. * Data structure for storing which hosts are permitted for forward requests.
* The local sides of any remote forwards are stored in this array to prevent * The local sides of any remote forwards are stored in this array to prevent
@ -106,17 +111,40 @@
/* XXX: streamlocal wants a path instead of host:port */ /* XXX: streamlocal wants a path instead of host:port */
/* Overload host_to_connect; we could just make this match Forward */ /* Overload host_to_connect; we could just make this match Forward */
/* XXX - can we use listen_host instead of listen_path? */ /* XXX - can we use listen_host instead of listen_path? */
typedef struct { struct permission {
char *host_to_connect; /* Connect to 'host'. */ char *host_to_connect; /* Connect to 'host'. */
int port_to_connect; /* Connect to 'port'. */ int port_to_connect; /* Connect to 'port'. */
char *listen_host; /* Remote side should listen address. */ char *listen_host; /* Remote side should listen address. */
char *listen_path; /* Remote side should listen path. */ char *listen_path; /* Remote side should listen path. */
int listen_port; /* Remote side should listen port. */ int listen_port; /* Remote side should listen port. */
Channel *downstream; /* Downstream mux*/ Channel *downstream; /* Downstream mux*/
} ForwardPermission; };
typedef void chan_fn(struct ssh *, Channel *c, /*
fd_set *readset, fd_set *writeset); * Stores the forwarding permission state for a single direction (local or
* remote).
*/
struct permission_set {
/*
* List of all local permitted host/port pairs to allow for the
* user.
*/
u_int num_permitted_user;
struct permission *permitted_user;
/*
* List of all permitted host/port pairs to allow for the admin.
*/
u_int num_permitted_admin;
struct permission *permitted_admin;
/*
* If this is true, all opens/listens are permitted. This is the
* case on the server on which we have to trust the client anyway,
* and the user could do anything after logging in.
*/
int all_permitted;
};
/* Master structure for channels state */ /* Master structure for channels state */
struct ssh_channels { struct ssh_channels {
@ -149,31 +177,8 @@ struct ssh_channels {
chan_fn **channel_post; chan_fn **channel_post;
/* -- tcp forwarding */ /* -- tcp forwarding */
struct permission_set local_perms;
/* List of all permitted host/port pairs to connect by the user. */ struct permission_set remote_perms;
ForwardPermission *permitted_opens;
/* List of all permitted host/port pairs to connect by the admin. */
ForwardPermission *permitted_adm_opens;
/*
* Number of permitted host/port pairs in the array permitted by
* the user.
*/
u_int num_permitted_opens;
/*
* Number of permitted host/port pair in the array permitted by
* the admin.
*/
u_int num_adm_permitted_opens;
/*
* If this is true, all opens are permitted. This is the case on
* the server on which we have to trust the client anyway, and the
* user could do anything after logging in anyway.
*/
int all_opens_permitted;
/* -- X11 forwarding */ /* -- X11 forwarding */
@ -448,50 +453,95 @@ channel_close_fds(struct ssh *ssh, Channel *c)
} }
static void static void
fwd_perm_clear(ForwardPermission *fp) fwd_perm_clear(struct permission *perm)
{ {
free(fp->host_to_connect); free(perm->host_to_connect);
free(fp->listen_host); free(perm->listen_host);
free(fp->listen_path); free(perm->listen_path);
bzero(fp, sizeof(*fp)); bzero(perm, sizeof(*perm));
} }
enum { FWDPERM_USER, FWDPERM_ADMIN }; /* Returns an printable name for the specified forwarding permission list */
static const char *
fwd_ident(int who, int where)
{
if (who == FORWARD_ADM) {
if (where == FORWARD_LOCAL)
return "admin local";
else if (where == FORWARD_REMOTE)
return "admin remote";
} else if (who == FORWARD_USER) {
if (where == FORWARD_LOCAL)
return "user local";
else if (where == FORWARD_REMOTE)
return "user remote";
}
fatal("Unknown forward permission list %d/%d", who, where);
}
/* Returns the forwarding permission list for the specified direction */
static struct permission_set *
permission_set_get(struct ssh *ssh, int where)
{
struct ssh_channels *sc = ssh->chanctxt;
switch (where) {
case FORWARD_LOCAL:
return &sc->local_perms;
break;
case FORWARD_REMOTE:
return &sc->remote_perms;
break;
default:
fatal("%s: invalid forwarding direction %d", __func__, where);
}
}
/* Reutrns pointers to the specified forwarding list and its element count */
static void
permission_set_get_array(struct ssh *ssh, int who, int where,
struct permission ***permpp, u_int **npermpp)
{
struct permission_set *pset = permission_set_get(ssh, where);
switch (who) {
case FORWARD_USER:
*permpp = &pset->permitted_user;
*npermpp = &pset->num_permitted_user;
break;
case FORWARD_ADM:
*permpp = &pset->permitted_admin;
*npermpp = &pset->num_permitted_admin;
break;
default:
fatal("%s: invalid forwarding client %d", __func__, who);
}
}
/* Adds an entry to the spcified forwarding list */
static int static int
fwd_perm_list_add(struct ssh *ssh, int which, permission_set_add(struct ssh *ssh, int who, int where,
const char *host_to_connect, int port_to_connect, const char *host_to_connect, int port_to_connect,
const char *listen_host, const char *listen_path, int listen_port, const char *listen_host, const char *listen_path, int listen_port,
Channel *downstream) Channel *downstream)
{ {
ForwardPermission **fpl; struct permission **permp;
u_int n, *nfpl; u_int n, *npermp;
switch (which) { permission_set_get_array(ssh, who, where, &permp, &npermp);
case FWDPERM_USER:
fpl = &ssh->chanctxt->permitted_opens;
nfpl = &ssh->chanctxt->num_permitted_opens;
break;
case FWDPERM_ADMIN:
fpl = &ssh->chanctxt->permitted_adm_opens;
nfpl = &ssh->chanctxt->num_adm_permitted_opens;
break;
default:
fatal("%s: invalid list %d", __func__, which);
}
if (*nfpl >= INT_MAX) if (*npermp >= INT_MAX)
fatal("%s: overflow", __func__); fatal("%s: %s overflow", __func__, fwd_ident(who, where));
*fpl = xrecallocarray(*fpl, *nfpl, *nfpl + 1, sizeof(**fpl)); *permp = xrecallocarray(*permp, *npermp, *npermp + 1, sizeof(**permp));
n = (*nfpl)++; n = (*npermp)++;
#define MAYBE_DUP(s) ((s == NULL) ? NULL : xstrdup(s)) #define MAYBE_DUP(s) ((s == NULL) ? NULL : xstrdup(s))
(*fpl)[n].host_to_connect = MAYBE_DUP(host_to_connect); (*permp)[n].host_to_connect = MAYBE_DUP(host_to_connect);
(*fpl)[n].port_to_connect = port_to_connect; (*permp)[n].port_to_connect = port_to_connect;
(*fpl)[n].listen_host = MAYBE_DUP(listen_host); (*permp)[n].listen_host = MAYBE_DUP(listen_host);
(*fpl)[n].listen_path = MAYBE_DUP(listen_path); (*permp)[n].listen_path = MAYBE_DUP(listen_path);
(*fpl)[n].listen_port = listen_port; (*permp)[n].listen_port = listen_port;
(*fpl)[n].downstream = downstream; (*permp)[n].downstream = downstream;
#undef MAYBE_DUP #undef MAYBE_DUP
return (int)n; return (int)n;
} }
@ -500,30 +550,31 @@ static void
mux_remove_remote_forwardings(struct ssh *ssh, Channel *c) mux_remove_remote_forwardings(struct ssh *ssh, Channel *c)
{ {
struct ssh_channels *sc = ssh->chanctxt; struct ssh_channels *sc = ssh->chanctxt;
ForwardPermission *fp; struct permission_set *pset = &sc->local_perms;
struct permission *perm;
int r; int r;
u_int i; u_int i;
for (i = 0; i < sc->num_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_user; i++) {
fp = &sc->permitted_opens[i]; perm = &pset->permitted_user[i];
if (fp->downstream != c) if (perm->downstream != c)
continue; continue;
/* cancel on the server, since mux client is gone */ /* cancel on the server, since mux client is gone */
debug("channel %d: cleanup remote forward for %s:%u", debug("channel %d: cleanup remote forward for %s:%u",
c->self, fp->listen_host, fp->listen_port); c->self, perm->listen_host, perm->listen_port);
if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
(r = sshpkt_put_cstring(ssh, (r = sshpkt_put_cstring(ssh,
"cancel-tcpip-forward")) != 0 || "cancel-tcpip-forward")) != 0 ||
(r = sshpkt_put_u8(ssh, 0)) != 0 || (r = sshpkt_put_u8(ssh, 0)) != 0 ||
(r = sshpkt_put_cstring(ssh, (r = sshpkt_put_cstring(ssh,
channel_rfwd_bind_host(fp->listen_host))) != 0 || channel_rfwd_bind_host(perm->listen_host))) != 0 ||
(r = sshpkt_put_u32(ssh, fp->listen_port)) != 0 || (r = sshpkt_put_u32(ssh, perm->listen_port)) != 0 ||
(r = sshpkt_send(ssh)) != 0) { (r = sshpkt_send(ssh)) != 0) {
fatal("%s: channel %i: %s", __func__, fatal("%s: channel %i: %s", __func__,
c->self, ssh_err(r)); c->self, ssh_err(r));
} }
fwd_perm_clear(fp); /* unregister */ fwd_perm_clear(perm); /* unregister */
} }
} }
@ -2729,7 +2780,7 @@ channel_proxy_downstream(struct ssh *ssh, Channel *downstream)
goto out; goto out;
} }
/* Record that connection to this host/port is permitted. */ /* Record that connection to this host/port is permitted. */
fwd_perm_list_add(ssh, FWDPERM_USER, "<mux>", -1, permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL, "<mux>", -1,
listen_host, NULL, (int)listen_port, downstream); listen_host, NULL, (int)listen_port, downstream);
listen_host = NULL; listen_host = NULL;
break; break;
@ -3637,11 +3688,78 @@ channel_setup_local_fwd_listener(struct ssh *ssh,
} }
} }
/* Matches a remote forwarding permission against a requested forwarding */
static int
remote_open_match(struct permission *allowed_open, struct Forward *fwd)
{
int ret;
char *lhost;
/* XXX add ACLs for streamlocal */
if (fwd->listen_path != NULL)
return 1;
if (fwd->listen_host == NULL || allowed_open->listen_host == NULL)
return 0;
if (allowed_open->listen_port != FWD_PERMIT_ANY_PORT &&
allowed_open->listen_port != fwd->listen_port)
return 0;
/* Match hostnames case-insensitively */
lhost = xstrdup(fwd->listen_host);
lowercase(lhost);
ret = match_pattern(lhost, allowed_open->listen_host);
free(lhost);
return ret;
}
/* Checks whether a requested remote forwarding is permitted */
static int
check_rfwd_permission(struct ssh *ssh, struct Forward *fwd)
{
struct ssh_channels *sc = ssh->chanctxt;
struct permission_set *pset = &sc->remote_perms;
u_int i, permit, permit_adm = 1;
struct permission *perm;
/* XXX apply GatewayPorts override before checking? */
permit = pset->all_permitted;
if (!permit) {
for (i = 0; i < pset->num_permitted_user; i++) {
perm = &pset->permitted_user[i];
if (remote_open_match(perm, fwd)) {
permit = 1;
break;
}
}
}
if (pset->num_permitted_admin > 0) {
permit_adm = 0;
for (i = 0; i < pset->num_permitted_admin; i++) {
perm = &pset->permitted_admin[i];
if (remote_open_match(perm, fwd)) {
permit_adm = 1;
break;
}
}
}
return permit && permit_adm;
}
/* protocol v2 remote port fwd, used by sshd */ /* protocol v2 remote port fwd, used by sshd */
int int
channel_setup_remote_fwd_listener(struct ssh *ssh, struct Forward *fwd, channel_setup_remote_fwd_listener(struct ssh *ssh, struct Forward *fwd,
int *allocated_listen_port, struct ForwardOptions *fwd_opts) int *allocated_listen_port, struct ForwardOptions *fwd_opts)
{ {
if (!check_rfwd_permission(ssh, fwd)) {
packet_send_debug("port forwarding refused");
return 0;
}
if (fwd->listen_path != NULL) { if (fwd->listen_path != NULL) {
return channel_setup_fwd_listener_streamlocal(ssh, return channel_setup_fwd_listener_streamlocal(ssh,
SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts); SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
@ -3671,7 +3789,7 @@ channel_rfwd_bind_host(const char *listen_host)
* Initiate forwarding of connections to port "port" on remote host through * Initiate forwarding of connections to port "port" on remote host through
* the secure channel to host:port from local side. * the secure channel to host:port from local side.
* Returns handle (index) for updating the dynamic listen port with * Returns handle (index) for updating the dynamic listen port with
* channel_update_permitted_opens(). * channel_update_permission().
*/ */
int int
channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd) channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd)
@ -3724,7 +3842,7 @@ channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd)
listen_host = xstrdup(fwd->listen_host); listen_host = xstrdup(fwd->listen_host);
listen_port = fwd->listen_port; listen_port = fwd->listen_port;
} }
idx = fwd_perm_list_add(ssh, FWDPERM_USER, idx = permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL,
host_to_connect, port_to_connect, host_to_connect, port_to_connect,
listen_host, listen_path, listen_port, NULL); listen_host, listen_path, listen_port, NULL);
} }
@ -3732,7 +3850,7 @@ channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd)
} }
static int static int
open_match(ForwardPermission *allowed_open, const char *requestedhost, open_match(struct permission *allowed_open, const char *requestedhost,
int requestedport) int requestedport)
{ {
if (allowed_open->host_to_connect == NULL) if (allowed_open->host_to_connect == NULL)
@ -3753,7 +3871,7 @@ open_match(ForwardPermission *allowed_open, const char *requestedhost,
* and what we've sent to the remote server (channel_rfwd_bind_host) * and what we've sent to the remote server (channel_rfwd_bind_host)
*/ */
static int static int
open_listen_match_tcpip(ForwardPermission *allowed_open, open_listen_match_tcpip(struct permission *allowed_open,
const char *requestedhost, u_short requestedport, int translate) const char *requestedhost, u_short requestedport, int translate)
{ {
const char *allowed_host; const char *allowed_host;
@ -3775,7 +3893,7 @@ open_listen_match_tcpip(ForwardPermission *allowed_open,
} }
static int static int
open_listen_match_streamlocal(ForwardPermission *allowed_open, open_listen_match_streamlocal(struct permission *allowed_open,
const char *requestedpath) const char *requestedpath)
{ {
if (allowed_open->host_to_connect == NULL) if (allowed_open->host_to_connect == NULL)
@ -3797,17 +3915,18 @@ channel_request_rforward_cancel_tcpip(struct ssh *ssh,
const char *host, u_short port) const char *host, u_short port)
{ {
struct ssh_channels *sc = ssh->chanctxt; struct ssh_channels *sc = ssh->chanctxt;
struct permission_set *pset = &sc->local_perms;
int r; int r;
u_int i; u_int i;
ForwardPermission *fp; struct permission *perm;
for (i = 0; i < sc->num_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_user; i++) {
fp = &sc->permitted_opens[i]; perm = &pset->permitted_user[i];
if (open_listen_match_tcpip(fp, host, port, 0)) if (open_listen_match_tcpip(perm, host, port, 0))
break; break;
fp = NULL; perm = NULL;
} }
if (fp == NULL) { if (perm == NULL) {
debug("%s: requested forward not found", __func__); debug("%s: requested forward not found", __func__);
return -1; return -1;
} }
@ -3819,7 +3938,7 @@ channel_request_rforward_cancel_tcpip(struct ssh *ssh,
(r = sshpkt_send(ssh)) != 0) (r = sshpkt_send(ssh)) != 0)
fatal("%s: send cancel: %s", __func__, ssh_err(r)); fatal("%s: send cancel: %s", __func__, ssh_err(r));
fwd_perm_clear(fp); /* unregister */ fwd_perm_clear(perm); /* unregister */
return 0; return 0;
} }
@ -3832,17 +3951,18 @@ static int
channel_request_rforward_cancel_streamlocal(struct ssh *ssh, const char *path) channel_request_rforward_cancel_streamlocal(struct ssh *ssh, const char *path)
{ {
struct ssh_channels *sc = ssh->chanctxt; struct ssh_channels *sc = ssh->chanctxt;
struct permission_set *pset = &sc->local_perms;
int r; int r;
u_int i; u_int i;
ForwardPermission *fp; struct permission *perm;
for (i = 0; i < sc->num_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_user; i++) {
fp = &sc->permitted_opens[i]; perm = &pset->permitted_user[i];
if (open_listen_match_streamlocal(fp, path)) if (open_listen_match_streamlocal(perm, path))
break; break;
fp = NULL; perm = NULL;
} }
if (fp == NULL) { if (perm == NULL) {
debug("%s: requested forward not found", __func__); debug("%s: requested forward not found", __func__);
return -1; return -1;
} }
@ -3854,7 +3974,7 @@ channel_request_rforward_cancel_streamlocal(struct ssh *ssh, const char *path)
(r = sshpkt_send(ssh)) != 0) (r = sshpkt_send(ssh)) != 0)
fatal("%s: send cancel: %s", __func__, ssh_err(r)); fatal("%s: send cancel: %s", __func__, ssh_err(r));
fwd_perm_clear(fp); /* unregister */ fwd_perm_clear(perm); /* unregister */
return 0; return 0;
} }
@ -3876,25 +3996,64 @@ channel_request_rforward_cancel(struct ssh *ssh, struct Forward *fwd)
} }
/* /*
* Permits opening to any host/port if permitted_opens[] is empty. This is * Permits opening to any host/port if permitted_user[] is empty. This is
* usually called by the server, because the user could connect to any port * usually called by the server, because the user could connect to any port
* anyway, and the server has no way to know but to trust the client anyway. * anyway, and the server has no way to know but to trust the client anyway.
*/ */
void void
channel_permit_all_opens(struct ssh *ssh) channel_permit_all(struct ssh *ssh, int where)
{ {
if (ssh->chanctxt->num_permitted_opens == 0) struct permission_set *pset = permission_set_get(ssh, where);
ssh->chanctxt->all_opens_permitted = 1;
if (pset->num_permitted_user == 0)
pset->all_permitted = 1;
} }
/*
* Permit the specified host/port for forwarding.
*/
void void
channel_add_permitted_opens(struct ssh *ssh, char *host, int port) channel_add_permission(struct ssh *ssh, int who, int where,
char *host, int port)
{ {
struct ssh_channels *sc = ssh->chanctxt; int local = where == FORWARD_LOCAL;
struct permission_set *pset = permission_set_get(ssh, where);
debug("allow port forwarding to host %s port %d", host, port); debug("allow %s forwarding to host %s port %d",
fwd_perm_list_add(ssh, FWDPERM_USER, host, port, NULL, NULL, 0, NULL); fwd_ident(who, where), host, port);
sc->all_opens_permitted = 0; /*
* Remote forwards set listen_host/port, local forwards set
* host/port_to_connect.
*/
permission_set_add(ssh, who, where,
local ? host : 0, local ? port : 0,
local ? NULL : host, NULL, local ? 0 : port, NULL);
pset->all_permitted = 0;
}
/*
* Administratively disable forwarding.
*/
void
channel_disable_admin(struct ssh *ssh, int where)
{
channel_clear_permission(ssh, FORWARD_ADM, where);
permission_set_add(ssh, FORWARD_ADM, where,
NULL, 0, NULL, NULL, 0, NULL);
}
/*
* Clear a list of permitted opens.
*/
void
channel_clear_permission(struct ssh *ssh, int who, int where)
{
struct permission **permp;
u_int *npermp;
permission_set_get_array(ssh, who, where, &permp, &npermp);
*permp = xrecallocarray(*permp, *npermp, 0, sizeof(**permp));
*npermp = 0;
} }
/* /*
@ -3903,63 +4062,28 @@ channel_add_permitted_opens(struct ssh *ssh, char *host, int port)
* passed then they entry will be invalidated. * passed then they entry will be invalidated.
*/ */
void void
channel_update_permitted_opens(struct ssh *ssh, int idx, int newport) channel_update_permission(struct ssh *ssh, int idx, int newport)
{ {
struct ssh_channels *sc = ssh->chanctxt; struct permission_set *pset = &ssh->chanctxt->local_perms;
if (idx < 0 || (u_int)idx >= sc->num_permitted_opens) { if (idx < 0 || (u_int)idx >= pset->num_permitted_user) {
debug("%s: index out of range: %d num_permitted_opens %d", debug("%s: index out of range: %d num_permitted_user %d",
__func__, idx, sc->num_permitted_opens); __func__, idx, pset->num_permitted_user);
return; return;
} }
debug("%s allowed port %d for forwarding to host %s port %d", debug("%s allowed port %d for forwarding to host %s port %d",
newport > 0 ? "Updating" : "Removing", newport > 0 ? "Updating" : "Removing",
newport, newport,
sc->permitted_opens[idx].host_to_connect, pset->permitted_user[idx].host_to_connect,
sc->permitted_opens[idx].port_to_connect); pset->permitted_user[idx].port_to_connect);
if (newport <= 0) if (newport <= 0)
fwd_perm_clear(&sc->permitted_opens[idx]); fwd_perm_clear(&pset->permitted_user[idx]);
else { else {
sc->permitted_opens[idx].listen_port = pset->permitted_user[idx].listen_port =
(datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport; (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
} }
} }
int
channel_add_adm_permitted_opens(struct ssh *ssh, char *host, int port)
{
debug("config allows port forwarding to host %s port %d", host, port);
return fwd_perm_list_add(ssh, FWDPERM_ADMIN, host, port,
NULL, NULL, 0, NULL);
}
void
channel_disable_adm_local_opens(struct ssh *ssh)
{
channel_clear_adm_permitted_opens(ssh);
fwd_perm_list_add(ssh, FWDPERM_ADMIN, NULL, 0, NULL, NULL, 0, NULL);
}
void
channel_clear_permitted_opens(struct ssh *ssh)
{
struct ssh_channels *sc = ssh->chanctxt;
sc->permitted_opens = xrecallocarray(sc->permitted_opens,
sc->num_permitted_opens, 0, sizeof(*sc->permitted_opens));
sc->num_permitted_opens = 0;
}
void
channel_clear_adm_permitted_opens(struct ssh *ssh)
{
struct ssh_channels *sc = ssh->chanctxt;
sc->permitted_adm_opens = xrecallocarray(sc->permitted_adm_opens,
sc->num_adm_permitted_opens, 0, sizeof(*sc->permitted_adm_opens));
sc->num_adm_permitted_opens = 0;
}
/* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */ /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
int int
permitopen_port(const char *p) permitopen_port(const char *p)
@ -4148,19 +4272,21 @@ channel_connect_by_listen_address(struct ssh *ssh, const char *listen_host,
u_short listen_port, char *ctype, char *rname) u_short listen_port, char *ctype, char *rname)
{ {
struct ssh_channels *sc = ssh->chanctxt; struct ssh_channels *sc = ssh->chanctxt;
struct permission_set *pset = &sc->local_perms;
u_int i; u_int i;
ForwardPermission *fp; struct permission *perm;
for (i = 0; i < sc->num_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_user; i++) {
fp = &sc->permitted_opens[i]; perm = &pset->permitted_user[i];
if (open_listen_match_tcpip(fp, listen_host, listen_port, 1)) { if (open_listen_match_tcpip(perm,
if (fp->downstream) listen_host, listen_port, 1)) {
return fp->downstream; if (perm->downstream)
if (fp->port_to_connect == 0) return perm->downstream;
if (perm->port_to_connect == 0)
return rdynamic_connect_prepare(ssh, return rdynamic_connect_prepare(ssh,
ctype, rname); ctype, rname);
return connect_to(ssh, return connect_to(ssh,
fp->host_to_connect, fp->port_to_connect, perm->host_to_connect, perm->port_to_connect,
ctype, rname); ctype, rname);
} }
} }
@ -4174,14 +4300,15 @@ channel_connect_by_listen_path(struct ssh *ssh, const char *path,
char *ctype, char *rname) char *ctype, char *rname)
{ {
struct ssh_channels *sc = ssh->chanctxt; struct ssh_channels *sc = ssh->chanctxt;
struct permission_set *pset = &sc->local_perms;
u_int i; u_int i;
ForwardPermission *fp; struct permission *perm;
for (i = 0; i < sc->num_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_user; i++) {
fp = &sc->permitted_opens[i]; perm = &pset->permitted_user[i];
if (open_listen_match_streamlocal(fp, path)) { if (open_listen_match_streamlocal(perm, path)) {
return connect_to(ssh, return connect_to(ssh,
fp->host_to_connect, fp->port_to_connect, perm->host_to_connect, perm->port_to_connect,
ctype, rname); ctype, rname);
} }
} }
@ -4196,28 +4323,29 @@ channel_connect_to_port(struct ssh *ssh, const char *host, u_short port,
char *ctype, char *rname, int *reason, const char **errmsg) char *ctype, char *rname, int *reason, const char **errmsg)
{ {
struct ssh_channels *sc = ssh->chanctxt; struct ssh_channels *sc = ssh->chanctxt;
struct permission_set *pset = &sc->local_perms;
struct channel_connect cctx; struct channel_connect cctx;
Channel *c; Channel *c;
u_int i, permit, permit_adm = 1; u_int i, permit, permit_adm = 1;
int sock; int sock;
ForwardPermission *fp; struct permission *perm;
permit = sc->all_opens_permitted; permit = pset->all_permitted;
if (!permit) { if (!permit) {
for (i = 0; i < sc->num_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_user; i++) {
fp = &sc->permitted_opens[i]; perm = &pset->permitted_user[i];
if (open_match(fp, host, port)) { if (open_match(perm, host, port)) {
permit = 1; permit = 1;
break; break;
} }
} }
} }
if (sc->num_adm_permitted_opens > 0) { if (pset->num_permitted_admin > 0) {
permit_adm = 0; permit_adm = 0;
for (i = 0; i < sc->num_adm_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_admin; i++) {
fp = &sc->permitted_adm_opens[i]; perm = &pset->permitted_admin[i];
if (open_match(fp, host, port)) { if (open_match(perm, host, port)) {
permit_adm = 1; permit_adm = 1;
break; break;
} }
@ -4255,25 +4383,26 @@ channel_connect_to_path(struct ssh *ssh, const char *path,
char *ctype, char *rname) char *ctype, char *rname)
{ {
struct ssh_channels *sc = ssh->chanctxt; struct ssh_channels *sc = ssh->chanctxt;
struct permission_set *pset = &sc->local_perms;
u_int i, permit, permit_adm = 1; u_int i, permit, permit_adm = 1;
ForwardPermission *fp; struct permission *perm;
permit = sc->all_opens_permitted; permit = pset->all_permitted;
if (!permit) { if (!permit) {
for (i = 0; i < sc->num_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_user; i++) {
fp = &sc->permitted_opens[i]; perm = &pset->permitted_user[i];
if (open_match(fp, path, PORT_STREAMLOCAL)) { if (open_match(perm, path, PORT_STREAMLOCAL)) {
permit = 1; permit = 1;
break; break;
} }
} }
} }
if (sc->num_adm_permitted_opens > 0) { if (pset->num_permitted_admin > 0) {
permit_adm = 0; permit_adm = 0;
for (i = 0; i < sc->num_adm_permitted_opens; i++) { for (i = 0; i < pset->num_permitted_admin; i++) {
fp = &sc->permitted_adm_opens[i]; perm = &pset->permitted_admin[i];
if (open_match(fp, path, PORT_STREAMLOCAL)) { if (open_match(perm, path, PORT_STREAMLOCAL)) {
permit_adm = 1; permit_adm = 1;
break; break;
} }

26
channels.h
View File

@ -1,4 +1,4 @@
/* $OpenBSD: channels.h,v 1.130 2017/09/21 19:16:53 markus Exp $ */ /* $OpenBSD: channels.h,v 1.131 2018/06/06 18:22:41 djm Exp $ */
/* /*
* Author: Tatu Ylonen <ylo@cs.hut.fi> * Author: Tatu Ylonen <ylo@cs.hut.fi>
@ -63,6 +63,15 @@
#define CHANNEL_CANCEL_PORT_STATIC -1 #define CHANNEL_CANCEL_PORT_STATIC -1
/* TCP forwarding */
#define FORWARD_DENY 0
#define FORWARD_REMOTE (1)
#define FORWARD_LOCAL (1<<1)
#define FORWARD_ALLOW (FORWARD_REMOTE|FORWARD_LOCAL)
#define FORWARD_ADM 0x100
#define FORWARD_USER 0x101
struct ssh; struct ssh;
struct Channel; struct Channel;
typedef struct Channel Channel; typedef struct Channel Channel;
@ -283,16 +292,11 @@ int channel_find_open(struct ssh *);
struct Forward; struct Forward;
struct ForwardOptions; struct ForwardOptions;
void channel_set_af(struct ssh *, int af); void channel_set_af(struct ssh *, int af);
void channel_permit_all_opens(struct ssh *); void channel_permit_all(struct ssh *, int);
void channel_add_permitted_opens(struct ssh *, char *, int); void channel_add_permission(struct ssh *, int, int, char *, int);
int channel_add_adm_permitted_opens(struct ssh *, char *, int); void channel_clear_permission(struct ssh *, int, int);
void channel_copy_adm_permitted_opens(struct ssh *, void channel_disable_admin(struct ssh *, int);
const struct fwd_perm_list *); void channel_update_permission(struct ssh *, int, int);
void channel_disable_adm_local_opens(struct ssh *);
void channel_update_permitted_opens(struct ssh *, int, int);
void channel_clear_permitted_opens(struct ssh *);
void channel_clear_adm_permitted_opens(struct ssh *);
void channel_print_adm_permitted_opens(struct ssh *);
Channel *channel_connect_to_port(struct ssh *, const char *, u_short, Channel *channel_connect_to_port(struct ssh *, const char *, u_short,
char *, char *, int *, const char **); char *, char *, int *, const char **);
Channel *channel_connect_to_path(struct ssh *, const char *, char *, char *); Channel *channel_connect_to_path(struct ssh *, const char *, char *, char *);

6
mux.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: mux.c,v 1.69 2017/09/20 05:19:00 dtucker Exp $ */ /* $OpenBSD: mux.c,v 1.70 2018/06/06 18:22:41 djm Exp $ */
/* /*
* Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org> * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org>
* *
@ -634,7 +634,7 @@ mux_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
buffer_put_int(&out, MUX_S_REMOTE_PORT); buffer_put_int(&out, MUX_S_REMOTE_PORT);
buffer_put_int(&out, fctx->rid); buffer_put_int(&out, fctx->rid);
buffer_put_int(&out, rfwd->allocated_port); buffer_put_int(&out, rfwd->allocated_port);
channel_update_permitted_opens(ssh, rfwd->handle, channel_update_permission(ssh, rfwd->handle,
rfwd->allocated_port); rfwd->allocated_port);
} else { } else {
buffer_put_int(&out, MUX_S_OK); buffer_put_int(&out, MUX_S_OK);
@ -643,7 +643,7 @@ mux_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
goto out; goto out;
} else { } else {
if (rfwd->listen_port == 0) if (rfwd->listen_port == 0)
channel_update_permitted_opens(ssh, rfwd->handle, -1); channel_update_permission(ssh, rfwd->handle, -1);
if (rfwd->listen_path != NULL) if (rfwd->listen_path != NULL)
xasprintf(&failmsg, "remote port forwarding failed for " xasprintf(&failmsg, "remote port forwarding failed for "
"listen path %s", rfwd->listen_path); "listen path %s", rfwd->listen_path);

168
servconf.c
View File

@ -1,5 +1,5 @@
/* $OpenBSD: servconf.c,v 1.328 2018/04/10 00:10:49 djm Exp $ */ /* $OpenBSD: servconf.c,v 1.329 2018/06/06 18:22:41 djm Exp $ */
/* /*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved * All rights reserved
@ -160,6 +160,7 @@ initialize_server_options(ServerOptions *options)
options->num_accept_env = 0; options->num_accept_env = 0;
options->permit_tun = -1; options->permit_tun = -1;
options->permitted_opens = NULL; options->permitted_opens = NULL;
options->permitted_remote_opens = NULL;
options->adm_forced_command = NULL; options->adm_forced_command = NULL;
options->chroot_directory = NULL; options->chroot_directory = NULL;
options->authorized_keys_command = NULL; options->authorized_keys_command = NULL;
@ -462,7 +463,7 @@ typedef enum {
sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile, sClientAliveInterval, sClientAliveCountMax, sAuthorizedKeysFile,
sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor, sGssAuthentication, sGssCleanupCreds, sGssStrictAcceptor,
sAcceptEnv, sPermitTunnel, sAcceptEnv, sPermitTunnel,
sMatch, sPermitOpen, sForceCommand, sChrootDirectory, sMatch, sPermitOpen, sPermitRemoteOpen, sForceCommand, sChrootDirectory,
sUsePrivilegeSeparation, sAllowAgentForwarding, sUsePrivilegeSeparation, sAllowAgentForwarding,
sHostCertificate, sHostCertificate,
sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile, sRevokedKeys, sTrustedUserCAKeys, sAuthorizedPrincipalsFile,
@ -597,6 +598,7 @@ static struct {
{ "permituserrc", sPermitUserRC, SSHCFG_ALL }, { "permituserrc", sPermitUserRC, SSHCFG_ALL },
{ "match", sMatch, SSHCFG_ALL }, { "match", sMatch, SSHCFG_ALL },
{ "permitopen", sPermitOpen, SSHCFG_ALL }, { "permitopen", sPermitOpen, SSHCFG_ALL },
{ "permitremoteopen", sPermitRemoteOpen, SSHCFG_ALL },
{ "forcecommand", sForceCommand, SSHCFG_ALL }, { "forcecommand", sForceCommand, SSHCFG_ALL },
{ "chrootdirectory", sChrootDirectory, SSHCFG_ALL }, { "chrootdirectory", sChrootDirectory, SSHCFG_ALL },
{ "hostcertificate", sHostCertificate, SSHCFG_GLOBAL }, { "hostcertificate", sHostCertificate, SSHCFG_GLOBAL },
@ -632,6 +634,20 @@ static struct {
{ -1, NULL } { -1, NULL }
}; };
/* Returns an opcode name from its number */
static const char *
lookup_opcode_name(ServerOpCodes code)
{
u_int i;
for (i = 0; keywords[i].name != NULL; i++)
if (keywords[i].opcode == code)
return(keywords[i].name);
return "UNKNOWN";
}
/* /*
* Returns the number of the token pointed to by cp or sBadOption. * Returns the number of the token pointed to by cp or sBadOption.
*/ */
@ -813,42 +829,58 @@ process_queued_listen_addrs(ServerOptions *options)
options->num_queued_listens = 0; options->num_queued_listens = 0;
} }
/*
* Inform channels layer of permitopen options for a single forwarding
* direction (local/remote).
*/
static void
process_permitopen_list(struct ssh *ssh, ServerOpCodes opcode,
char **opens, u_int num_opens)
{
u_int i;
int port;
char *host, *arg, *oarg;
int where = opcode == sPermitOpen ? FORWARD_LOCAL : FORWARD_REMOTE;
const char *what = lookup_opcode_name(opcode);
channel_clear_permission(ssh, FORWARD_ADM, where);
if (num_opens == 0)
return; /* permit any */
/* handle keywords: "any" / "none" */
if (num_opens == 1 && strcmp(opens[0], "any") == 0)
return;
if (num_opens == 1 && strcmp(opens[0], "none") == 0) {
channel_disable_admin(ssh, where);
return;
}
/* Otherwise treat it as a list of permitted host:port */
for (i = 0; i < num_opens; i++) {
oarg = arg = xstrdup(opens[i]);
host = hpdelim(&arg);
if (host == NULL)
fatal("%s: missing host in %s", __func__, what);
host = cleanhostname(host);
if (arg == NULL || ((port = permitopen_port(arg)) < 0))
fatal("%s: bad port number in %s", __func__, what);
/* Send it to channels layer */
channel_add_permission(ssh, FORWARD_ADM,
where, host, port);
free(oarg);
}
}
/* /*
* Inform channels layer of permitopen options from configuration. * Inform channels layer of permitopen options from configuration.
*/ */
void void
process_permitopen(struct ssh *ssh, ServerOptions *options) process_permitopen(struct ssh *ssh, ServerOptions *options)
{ {
u_int i; process_permitopen_list(ssh, sPermitOpen,
int port; options->permitted_opens, options->num_permitted_opens);
char *host, *arg, *oarg; process_permitopen_list(ssh, sPermitRemoteOpen,
options->permitted_remote_opens,
channel_clear_adm_permitted_opens(ssh); options->num_permitted_remote_opens);
if (options->num_permitted_opens == 0)
return; /* permit any */
/* handle keywords: "any" / "none" */
if (options->num_permitted_opens == 1 &&
strcmp(options->permitted_opens[0], "any") == 0)
return;
if (options->num_permitted_opens == 1 &&
strcmp(options->permitted_opens[0], "none") == 0) {
channel_disable_adm_local_opens(ssh);
return;
}
/* Otherwise treat it as a list of permitted host:port */
for (i = 0; i < options->num_permitted_opens; i++) {
oarg = arg = xstrdup(options->permitted_opens[i]);
host = hpdelim(&arg);
if (host == NULL)
fatal("%s: missing host in PermitOpen", __func__);
host = cleanhostname(host);
if (arg == NULL || ((port = permitopen_port(arg)) < 0))
fatal("%s: bad port number in PermitOpen", __func__);
/* Send it to channels layer */
channel_add_adm_permitted_opens(ssh, host, port);
free(oarg);
}
} }
struct connection_info * struct connection_info *
@ -1144,12 +1176,12 @@ process_server_config_line(ServerOptions *options, char *line,
const char *filename, int linenum, int *activep, const char *filename, int linenum, int *activep,
struct connection_info *connectinfo) struct connection_info *connectinfo)
{ {
char *cp, **charptr, *arg, *arg2, *p; char *cp, ***chararrayptr, **charptr, *arg, *arg2, *p;
int cmdline = 0, *intptr, value, value2, n, port; int cmdline = 0, *intptr, value, value2, n, port;
SyslogFacility *log_facility_ptr; SyslogFacility *log_facility_ptr;
LogLevel *log_level_ptr; LogLevel *log_level_ptr;
ServerOpCodes opcode; ServerOpCodes opcode;
u_int i, flags = 0; u_int i, *uintptr, uvalue, flags = 0;
size_t len; size_t len;
long long val64; long long val64;
const struct multistate *multistate_ptr; const struct multistate *multistate_ptr;
@ -1799,36 +1831,49 @@ process_server_config_line(ServerOptions *options, char *line,
*activep = value; *activep = value;
break; break;
case sPermitRemoteOpen:
case sPermitOpen: case sPermitOpen:
if (opcode == sPermitRemoteOpen) {
uintptr = &options->num_permitted_remote_opens;
chararrayptr = &options->permitted_remote_opens;
} else {
uintptr = &options->num_permitted_opens;
chararrayptr = &options->permitted_opens;
}
arg = strdelim(&cp); arg = strdelim(&cp);
if (!arg || *arg == '\0') if (!arg || *arg == '\0')
fatal("%s line %d: missing PermitOpen specification", fatal("%s line %d: missing %s specification",
filename, linenum); filename, linenum, lookup_opcode_name(opcode));
value = options->num_permitted_opens; /* modified later */ uvalue = *uintptr; /* modified later */
if (strcmp(arg, "any") == 0 || strcmp(arg, "none") == 0) { if (strcmp(arg, "any") == 0 || strcmp(arg, "none") == 0) {
if (*activep && value == 0) { if (*activep && uvalue == 0) {
options->num_permitted_opens = 1; *uintptr = 1;
options->permitted_opens = xcalloc(1, *chararrayptr = xcalloc(1,
sizeof(*options->permitted_opens)); sizeof(**chararrayptr));
options->permitted_opens[0] = xstrdup(arg); (*chararrayptr)[0] = xstrdup(arg);
} }
break; break;
} }
for (; arg != NULL && *arg != '\0'; arg = strdelim(&cp)) { for (; arg != NULL && *arg != '\0'; arg = strdelim(&cp)) {
arg2 = xstrdup(arg); arg2 = xstrdup(arg);
p = hpdelim(&arg); p = hpdelim(&arg);
if (p == NULL) /* XXX support bare port number for PermitRemoteOpen */
fatal("%s line %d: missing host in PermitOpen", if (p == NULL) {
filename, linenum); fatal("%s line %d: missing host in %s",
filename, linenum,
lookup_opcode_name(opcode));
}
p = cleanhostname(p); p = cleanhostname(p);
if (arg == NULL || ((port = permitopen_port(arg)) < 0)) if (arg == NULL ||
fatal("%s line %d: bad port number in " ((port = permitopen_port(arg)) < 0)) {
"PermitOpen", filename, linenum); fatal("%s line %d: bad port number in %s",
if (*activep && value == 0) { filename, linenum,
lookup_opcode_name(opcode));
}
if (*activep && uvalue == 0) {
array_append(filename, linenum, array_append(filename, linenum,
"PermitOpen", lookup_opcode_name(opcode),
&options->permitted_opens, chararrayptr, uintptr, arg2);
&options->num_permitted_opens, arg2);
} }
free(arg2); free(arg2);
} }
@ -2307,17 +2352,6 @@ fmt_intarg(ServerOpCodes code, int val)
} }
} }
static const char *
lookup_opcode_name(ServerOpCodes code)
{
u_int i;
for (i = 0; keywords[i].name != NULL; i++)
if (keywords[i].opcode == code)
return(keywords[i].name);
return "UNKNOWN";
}
static void static void
dump_cfg_int(ServerOpCodes code, int val) dump_cfg_int(ServerOpCodes code, int val)
{ {
@ -2562,4 +2596,12 @@ dump_config(ServerOptions *o)
printf(" %s", o->permitted_opens[i]); printf(" %s", o->permitted_opens[i]);
} }
printf("\n"); printf("\n");
printf("permitremoteopen");
if (o->num_permitted_remote_opens == 0)
printf(" any");
else {
for (i = 0; i < o->num_permitted_remote_opens; i++)
printf(" %s", o->permitted_remote_opens[i]);
}
printf("\n");
} }

16
servconf.h
View File

@ -1,4 +1,4 @@
/* $OpenBSD: servconf.h,v 1.131 2018/04/13 03:57:26 dtucker Exp $ */ /* $OpenBSD: servconf.h,v 1.132 2018/06/06 18:22:41 djm Exp $ */
/* /*
* Author: Tatu Ylonen <ylo@cs.hut.fi> * Author: Tatu Ylonen <ylo@cs.hut.fi>
@ -32,12 +32,6 @@
#define PRIVSEP_ON 1 #define PRIVSEP_ON 1
#define PRIVSEP_NOSANDBOX 2 #define PRIVSEP_NOSANDBOX 2
/* AllowTCPForwarding */
#define FORWARD_DENY 0
#define FORWARD_REMOTE (1)
#define FORWARD_LOCAL (1<<1)
#define FORWARD_ALLOW (FORWARD_REMOTE|FORWARD_LOCAL)
/* PermitOpen */ /* PermitOpen */
#define PERMITOPEN_ANY 0 #define PERMITOPEN_ANY 0
#define PERMITOPEN_NONE -2 #define PERMITOPEN_NONE -2
@ -187,8 +181,10 @@ typedef struct {
int permit_tun; int permit_tun;
char **permitted_opens; char **permitted_opens; /* May also be one of PERMITOPEN_* */
u_int num_permitted_opens; /* May also be one of PERMITOPEN_* */ u_int num_permitted_opens;
char **permitted_remote_opens; /* May also be one of PERMITOPEN_* */
u_int num_permitted_remote_opens;
char *chroot_directory; char *chroot_directory;
char *revoked_keys_file; char *revoked_keys_file;
@ -252,6 +248,8 @@ struct connection_info {
M_CP_STRARRAYOPT(accept_env, num_accept_env); \ M_CP_STRARRAYOPT(accept_env, num_accept_env); \
M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \ M_CP_STRARRAYOPT(auth_methods, num_auth_methods); \
M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \ M_CP_STRARRAYOPT(permitted_opens, num_permitted_opens); \
M_CP_STRARRAYOPT(permitted_remote_opens, \
num_permitted_remote_opens); \
} while (0) } while (0)
struct connection_info *get_connection_info(int, int); struct connection_info *get_connection_info(int, int);

27
session.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: session.c,v 1.295 2018/06/01 03:33:53 djm Exp $ */ /* $OpenBSD: session.c,v 1.296 2018/06/06 18:22:41 djm Exp $ */
/* /*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved * All rights reserved
@ -298,7 +298,7 @@ set_permitopen_from_authopts(struct ssh *ssh, const struct sshauthopt *opts)
if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0) if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
return; return;
channel_clear_permitted_opens(ssh); channel_clear_permission(ssh, FORWARD_USER, FORWARD_LOCAL);
for (i = 0; i < auth_opts->npermitopen; i++) { for (i = 0; i < auth_opts->npermitopen; i++) {
tmp = cp = xstrdup(auth_opts->permitopen[i]); tmp = cp = xstrdup(auth_opts->permitopen[i]);
/* This shouldn't fail as it has already been checked */ /* This shouldn't fail as it has already been checked */
@ -308,7 +308,8 @@ set_permitopen_from_authopts(struct ssh *ssh, const struct sshauthopt *opts)
if (cp == NULL || (port = permitopen_port(cp)) < 0) if (cp == NULL || (port = permitopen_port(cp)) < 0)
fatal("%s: internal error: permitopen port", fatal("%s: internal error: permitopen port",
__func__); __func__);
channel_add_permitted_opens(ssh, host, port); channel_add_permission(ssh, FORWARD_USER, FORWARD_LOCAL,
host, port);
free(tmp); free(tmp);
} }
} }
@ -323,13 +324,21 @@ do_authenticated(struct ssh *ssh, Authctxt *authctxt)
/* setup the channel layer */ /* setup the channel layer */
/* XXX - streamlocal? */ /* XXX - streamlocal? */
set_permitopen_from_authopts(ssh, auth_opts); set_permitopen_from_authopts(ssh, auth_opts);
if (!auth_opts->permit_port_forwarding_flag ||
options.disable_forwarding ||
(options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
channel_disable_adm_local_opens(ssh);
else
channel_permit_all_opens(ssh);
if (!auth_opts->permit_port_forwarding_flag ||
options.disable_forwarding) {
channel_disable_admin(ssh, FORWARD_LOCAL);
channel_disable_admin(ssh, FORWARD_REMOTE);
} else {
if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
channel_disable_admin(ssh, FORWARD_LOCAL);
else
channel_permit_all(ssh, FORWARD_LOCAL);
if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0)
channel_disable_admin(ssh, FORWARD_REMOTE);
else
channel_permit_all(ssh, FORWARD_REMOTE);
}
auth_debug_send(); auth_debug_send();
prepare_auth_info_file(authctxt->pw, authctxt->session_info); prepare_auth_info_file(authctxt->pw, authctxt->session_info);

6
ssh.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: ssh.c,v 1.479 2018/06/01 03:33:53 djm Exp $ */ /* $OpenBSD: ssh.c,v 1.480 2018/06/06 18:22:41 djm Exp $ */
/* /*
* Author: Tatu Ylonen <ylo@cs.hut.fi> * Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -1654,10 +1654,10 @@ ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
logit("Allocated port %u for remote forward to %s:%d", logit("Allocated port %u for remote forward to %s:%d",
rfwd->allocated_port, rfwd->allocated_port,
rfwd->connect_host, rfwd->connect_port); rfwd->connect_host, rfwd->connect_port);
channel_update_permitted_opens(ssh, channel_update_permission(ssh,
rfwd->handle, rfwd->allocated_port); rfwd->handle, rfwd->allocated_port);
} else { } else {
channel_update_permitted_opens(ssh, rfwd->handle, -1); channel_update_permission(ssh, rfwd->handle, -1);
} }
} }