]> andersk Git - openssh.git/commitdiff
- markus@cvs.openbsd.org 2001/03/16 19:06:30
authormouring <mouring>
Sat, 17 Mar 2001 00:47:54 +0000 (00:47 +0000)
committermouring <mouring>
Sat, 17 Mar 2001 00:47:54 +0000 (00:47 +0000)
     [auth-options.c channels.c channels.h serverloop.c session.c]
     implement "permitopen" key option, restricts -L style forwarding to
     to specified host:port pairs. based on work by harlan@genua.de

ChangeLog
auth-options.c
channels.c
channels.h
serverloop.c
session.c

index b3a487ddefc6073abef1a29319343a78a2acb673..377a6be8d734e1ba2818892b274243ed08b1bd49 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
    - markus@cvs.openbsd.org 2001/03/16 13:44:24
      [sftp-int.c]
      discourage strcat/strcpy
+   - markus@cvs.openbsd.org 2001/03/16 19:06:30
+     [auth-options.c channels.c channels.h serverloop.c session.c]
+     implement "permitopen" key option, restricts -L style forwarding to
+     to specified host:port pairs. based on work by harlan@genua.de
 
 20010315
  - OpenBSD CVS Sync
index bfb1af86b32bb957a1038c78fc8a3c67c7f8d607..7ce1e4b0c5cc3584ff905055f738fb0c4e71ae0c 100644 (file)
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: auth-options.c,v 1.14 2001/03/13 17:34:42 markus Exp $");
+RCSID("$OpenBSD: auth-options.c,v 1.15 2001/03/16 19:06:28 markus Exp $");
 
 #include "packet.h"
 #include "xmalloc.h"
 #include "match.h"
 #include "log.h"
 #include "canohost.h"
+#include "channels.h"
 #include "auth-options.h"
 #include "servconf.h"
 
@@ -51,6 +52,7 @@ auth_clear_options(void)
                xfree(forced_command);
                forced_command = NULL;
        }
+       channel_clear_permitted_opens();
 }
 
 /*
@@ -61,6 +63,7 @@ int
 auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
 {
        const char *cp;
+       int i;
 
        /* reset options */
        auth_clear_options();
@@ -99,7 +102,6 @@ auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
                }
                cp = "command=\"";
                if (strncasecmp(opts, cp, strlen(cp)) == 0) {
-                       int i;
                        opts += strlen(cp);
                        forced_command = xmalloc(strlen(opts) + 1);
                        i = 0;
@@ -129,9 +131,9 @@ auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
                }
                cp = "environment=\"";
                if (strncasecmp(opts, cp, strlen(cp)) == 0) {
-                       int i;
                        char *s;
                        struct envstring *new_envstring;
+
                        opts += strlen(cp);
                        s = xmalloc(strlen(opts) + 1);
                        i = 0;
@@ -170,7 +172,7 @@ auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
                        const char *remote_host = get_canonical_hostname(
                            options.reverse_mapping_check);
                        char *patterns = xmalloc(strlen(opts) + 1);
-                       int i;
+
                        opts += strlen(cp);
                        i = 0;
                        while (*opts) {
@@ -218,6 +220,58 @@ auth_parse_options(struct passwd *pw, char *opts, char *file, u_long linenum)
                        /* Host name matches. */
                        goto next_option;
                }
+               cp = "permitopen=\"";
+               if (strncasecmp(opts, cp, strlen(cp)) == 0) {
+                       u_short port;
+                       char *c, *ep;
+                       char *patterns = xmalloc(strlen(opts) + 1);
+
+                       opts += strlen(cp);
+                       i = 0;
+                       while (*opts) {
+                               if (*opts == '"')
+                                       break;
+                               if (*opts == '\\' && opts[1] == '"') {
+                                       opts += 2;
+                                       patterns[i++] = '"';
+                                       continue;
+                               }
+                               patterns[i++] = *opts++;
+                       }
+                       if (!*opts) {
+                               debug("%.100s, line %lu: missing end quote",
+                                   file, linenum);
+                               packet_send_debug("%.100s, line %lu: missing end quote",
+                                   file, linenum);
+                               xfree(patterns);
+                               goto bad_option;
+                       }
+                       patterns[i] = 0;
+                       opts++;
+                       c = strchr(patterns, ':');
+                       if (c == NULL) {
+                               debug("%.100s, line %lu: permitopen: missing colon <%.100s>",
+                                   file, linenum, patterns);
+                               packet_send_debug("%.100s, line %lu: missing colon",
+                                   file, linenum);
+                               xfree(patterns);
+                               goto bad_option;
+                       }
+                       *c = 0;
+                       c++;
+                       port = strtol(c, &ep, 0);
+                       if (c == ep) {
+                               debug("%.100s, line %lu: permitopen: missing port <%.100s>",
+                                   file, linenum, patterns);
+                               packet_send_debug("%.100s, line %lu: missing port",
+                                   file, linenum);
+                               xfree(patterns);
+                               goto bad_option;
+                       }
+                       channel_add_permitted_opens(patterns, port);
+                       xfree(patterns);
+                       goto next_option;
+               }
 next_option:
                /*
                 * Skip the comma, and move to the next option
index bb872dc94723ee48b23b3b27203693cf10d3a0b4..941556ace0c5253ff424b324f618f7126154bfdf 100644 (file)
@@ -40,7 +40,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.98 2001/03/04 17:42:28 millert Exp $");
+RCSID("$OpenBSD: channels.c,v 1.99 2001/03/16 19:06:29 markus Exp $");
 
 #include <openssl/rsa.h>
 #include <openssl/dsa.h>
@@ -141,18 +141,6 @@ channel_set_options(int hostname_in_open)
        have_hostname_in_open = hostname_in_open;
 }
 
-/*
- * Permits opening to any host/port in SSH_MSG_PORT_OPEN.  This is 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.
- */
-
-void
-channel_permit_all_opens()
-{
-       all_opens_permitted = 1;
-}
-
 /* lookup channel by id */
 
 Channel *
@@ -1791,9 +1779,47 @@ channel_input_port_forward_request(int is_root, int gateway_ports)
        xfree(hostname);
 }
 
-/* XXX move to aux.c */
+/*
+ * Permits opening to any host/port if permitted_opens[] is empty.  This is
+ * 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.
+ */
+void
+channel_permit_all_opens()
+{
+       if (num_permitted_opens == 0)
+               all_opens_permitted = 1;
+}
+
+void 
+channel_add_permitted_opens(char *host, int port)
+{
+       if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
+               fatal("channel_request_remote_forwarding: too many forwards");
+       debug("allow port forwarding to host %s port %d", host, port);
+
+       permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
+       permitted_opens[num_permitted_opens].port_to_connect = port;
+       num_permitted_opens++;
+
+       all_opens_permitted = 0;
+}
+
+void 
+channel_clear_permitted_opens(void)
+{
+       int i;
+
+       for (i = 0; i < num_permitted_opens; i++)
+               xfree(permitted_opens[i].host_to_connect);
+       num_permitted_opens = 0;
+
+}
+
+
+/* return socket to remote host, port */
 int
-channel_connect_to(const char *host, u_short host_port)
+connect_to(const char *host, u_short port)
 {
        struct addrinfo hints, *ai, *aitop;
        char ntop[NI_MAXHOST], strport[NI_MAXSERV];
@@ -1803,9 +1829,10 @@ channel_connect_to(const char *host, u_short host_port)
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = IPv4or6;
        hints.ai_socktype = SOCK_STREAM;
-       snprintf(strport, sizeof strport, "%d", host_port);
+       snprintf(strport, sizeof strport, "%d", port);
        if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
-               error("%.100s: unknown host (%s)", host, gai_strerror(gaierr));
+               error("connect_to %.100s: unknown host (%s)", host,
+                   gai_strerror(gaierr));
                return -1;
        }
        for (ai = aitop; ai; ai = ai->ai_next) {
@@ -1813,10 +1840,9 @@ channel_connect_to(const char *host, u_short host_port)
                        continue;
                if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
                    strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
-                       error("channel_connect_to: getnameinfo failed");
+                       error("connect_to: getnameinfo failed");
                        continue;
                }
-               /* Create the socket. */
                sock = socket(ai->ai_family, SOCK_STREAM, 0);
                if (sock < 0) {
                        error("socket: %.100s", strerror(errno));
@@ -1824,10 +1850,9 @@ channel_connect_to(const char *host, u_short host_port)
                }
                if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)
                        fatal("connect_to: F_SETFL: %s", strerror(errno));
-               /* Connect to the host/port. */
                if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
                    errno != EINPROGRESS) {
-                       error("connect %.100s port %s: %.100s", ntop, strport,
+                       error("connect_to %.100s port %s: %.100s", ntop, strport,
                            strerror(errno));
                        close(sock);
                        continue;       /* fail -- try next */
@@ -1837,19 +1862,21 @@ channel_connect_to(const char *host, u_short host_port)
        }
        freeaddrinfo(aitop);
        if (!ai) {
-               error("connect %.100s port %d: failed.", host, host_port);
+               error("connect_to %.100s port %d: failed.", host, port);
                return -1;
        }
        /* success */
        return sock;
 }
+
 int
 channel_connect_by_listen_adress(u_short listen_port)
 {
        int i;
+
        for (i = 0; i < num_permitted_opens; i++)
                if (permitted_opens[i].listen_port == listen_port)
-                       return channel_connect_to(
+                       return connect_to(
                            permitted_opens[i].host_to_connect,
                            permitted_opens[i].port_to_connect);
        error("WARNING: Server requests forwarding for unknown listen_port %d",
@@ -1857,6 +1884,28 @@ channel_connect_by_listen_adress(u_short listen_port)
        return -1;
 }
 
+/* Check if connecting to that port is permitted and connect. */
+int
+channel_connect_to(const char *host, u_short port)
+{
+       int i, permit;
+
+       permit = all_opens_permitted;
+       if (!permit) {
+               for (i = 0; i < num_permitted_opens; i++)
+                       if (permitted_opens[i].port_to_connect == port &&
+                           strcmp(permitted_opens[i].host_to_connect, host) == 0)
+                               permit = 1;
+
+       }
+       if (!permit) {
+               log("Received request to connect to host %.100s port %d, "
+                   "but the request was denied.", host, port);
+               return -1;
+       }
+       return connect_to(host, port);
+}
+
 /*
  * This is called after receiving PORT_OPEN message.  This attempts to
  * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION
@@ -1868,55 +1917,25 @@ channel_input_port_open(int type, int plen, void *ctxt)
 {
        u_short host_port;
        char *host, *originator_string;
-       int remote_channel, sock = -1, newch, i, denied;
-       u_int host_len, originator_len;
+       int remote_channel, sock = -1, newch;
 
-       /* Get remote channel number. */
        remote_channel = packet_get_int();
-
-       /* Get host name to connect to. */
-       host = packet_get_string(&host_len);
-
-       /* Get port to connect to. */
+       host = packet_get_string(NULL);
        host_port = packet_get_int();
 
-       /* Get remote originator name. */
        if (have_hostname_in_open) {
-               originator_string = packet_get_string(&originator_len);
-               originator_len += 4;    /* size of packet_int */
+               originator_string = packet_get_string(NULL);
        } else {
                originator_string = xstrdup("unknown (remote did not supply name)");
-               originator_len = 0;     /* no originator supplied */
-       }
-
-       packet_integrity_check(plen,
-           4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN);
-
-       /* Check if opening that port is permitted. */
-       denied = 0;
-       if (!all_opens_permitted) {
-               /* Go trough all permitted ports. */
-               for (i = 0; i < num_permitted_opens; i++)
-                       if (permitted_opens[i].port_to_connect == host_port &&
-                           strcmp(permitted_opens[i].host_to_connect, host) == 0)
-                               break;
-
-               /* Check if we found the requested port among those permitted. */
-               if (i >= num_permitted_opens) {
-                       /* The port is not permitted. */
-                       log("Received request to connect to %.100s:%d, but the request was denied.",
-                           host, host_port);
-                       denied = 1;
-               }
        }
-       sock = denied ? -1 : channel_connect_to(host, host_port);
-       if (sock > 0) {
-               /* Allocate a channel for this connection. */
+       packet_done();
+       sock = channel_connect_to(host, host_port);
+       if (sock != -1) {
                newch = channel_allocate(SSH_CHANNEL_CONNECTING,
                    sock, originator_string);
-/*XXX delay answer? */
                channels[newch].remote_id = remote_channel;
 
+               /*XXX delay answer? */
                packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
                packet_put_int(remote_channel);
                packet_put_int(newch);
index f57029a14e545c83f09785600d16c92e4e2dde80..493b04aa2903e2d5da5b681510cda245c517309b 100644 (file)
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-/* RCSID("$OpenBSD: channels.h,v 1.27 2001/02/15 23:19:59 markus Exp $"); */
+/* RCSID("$OpenBSD: channels.h,v 1.28 2001/03/16 19:06:29 markus Exp $"); */
 
 #ifndef CHANNELS_H
 #define CHANNELS_H
 
+#include "buffer.h"
+
 /* Definitions for channel types. */
 #define SSH_CHANNEL_FREE               0       /* This channel is free (unused). */
 #define SSH_CHANNEL_X11_LISTENER       1       /* Listening for inet X11 conn. */
@@ -226,12 +228,18 @@ channel_request_remote_forwarding(u_short port, const char *host,
     u_short remote_port);
 
 /*
- * Permits opening to any host/port in SSH_MSG_PORT_OPEN.  This is 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.
+ * Permits opening to any host/port if permitted_opens[] is empty.  This is
+ * 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.
  */
 void    channel_permit_all_opens(void);
 
+/* Add host/port to list of allowed targets for port forwarding */
+void   channel_add_permitted_opens(char *host, int port);
+
+/* Flush list */
+void   channel_clear_permitted_opens(void);
+
 /*
  * This is called after receiving CHANNEL_FORWARDING_REQUEST.  This initates
  * listening for the port, and sends back a success reply (or disconnect
index 8b1ee99190cb82a12fa8164454f18facc62ed181..66bc52573d7534de97884dfb6e9748cc0f26cad7 100644 (file)
@@ -35,7 +35,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: serverloop.c,v 1.54 2001/03/04 01:46:30 djm Exp $");
+RCSID("$OpenBSD: serverloop.c,v 1.55 2001/03/16 19:06:29 markus Exp $");
 
 #include "xmalloc.h"
 #include "packet.h"
@@ -756,11 +756,6 @@ server_request_direct_tcpip(char *ctype)
           originator, originator_port, target, target_port);
 
        /* XXX check permission */
-       if (no_port_forwarding_flag || !options.allow_tcp_forwarding) {
-               xfree(target);
-               xfree(originator);
-               return NULL;
-       }
        sock = channel_connect_to(target, target_port);
        xfree(target);
        xfree(originator);
@@ -858,6 +853,7 @@ server_input_global_request(int type, int plen, void *ctxt)
        want_reply = packet_get_char();
        debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
 
+       /* -R style forwarding */
        if (strcmp(rtype, "tcpip-forward") == 0) {
                struct passwd *pw;
                char *listen_address;
index 5e6926b56dab0140f77fe21b86053698c68752f6..9c4828ac7ca5092945e72414d118ffe19a598c10 100644 (file)
--- a/session.c
+++ b/session.c
@@ -33,7 +33,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.60 2001/03/15 22:07:08 markus Exp $");
+RCSID("$OpenBSD: session.c,v 1.61 2001/03/16 19:06:30 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -228,13 +228,6 @@ do_authenticated(struct passwd * pw)
                startup_pipe = -1;
        }
 
-       /*
-        * Inform the channel mechanism that we are the server side and that
-        * the client may request to connect to any port at all. (The user
-        * could do it anyway, and we wouldn\'t know what is permitted except
-        * by the client telling us, so we can equally well trust the client
-        * not to request anything bogus.)
-        */
        if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
                channel_permit_all_opens();
 
@@ -2037,6 +2030,8 @@ do_authenticated2(Authctxt *authctxt)
                close(startup_pipe);
                startup_pipe = -1;
        }
+       if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
+               channel_permit_all_opens();
 #if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD)
        if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) {
                error("unable to get login class");
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