summaryrefslogtreecommitdiffstats
path: root/debian/patches/restore-tcp-wrappers.patch
diff options
context:
space:
mode:
Diffstat (limited to 'debian/patches/restore-tcp-wrappers.patch')
-rw-r--r--debian/patches/restore-tcp-wrappers.patch172
1 files changed, 172 insertions, 0 deletions
diff --git a/debian/patches/restore-tcp-wrappers.patch b/debian/patches/restore-tcp-wrappers.patch
new file mode 100644
index 0000000..404c696
--- /dev/null
+++ b/debian/patches/restore-tcp-wrappers.patch
@@ -0,0 +1,172 @@
+From 8cee1ce3e07ac7904468ab8076ad5595048fb4c9 Mon Sep 17 00:00:00 2001
+From: Colin Watson <cjwatson@debian.org>
+Date: Tue, 7 Oct 2014 13:22:41 +0100
+Subject: Restore TCP wrappers support
+
+Support for TCP wrappers was dropped in OpenSSH 6.7. See this message
+and thread:
+
+ https://lists.mindrot.org/pipermail/openssh-unix-dev/2014-April/032497.html
+
+It is true that this reduces preauth attack surface in sshd. On the
+other hand, this support seems to be quite widely used, and abruptly
+dropping it (from the perspective of users who don't read
+openssh-unix-dev) could easily cause more serious problems in practice.
+
+It's not entirely clear what the right long-term answer for Debian is,
+but it at least probably doesn't involve dropping this feature shortly
+before a freeze.
+
+Forwarded: not-needed
+Last-Update: 2022-02-23
+
+Patch-Name: restore-tcp-wrappers.patch
+---
+ configure.ac | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++
+ sshd.8 | 7 +++++++
+ sshd.c | 25 +++++++++++++++++++++++
+ 3 files changed, 89 insertions(+)
+
+diff --git a/configure.ac b/configure.ac
+index 75a9e5670..0c59c8b50 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -1667,6 +1667,62 @@ else
+ AC_MSG_RESULT([no])
+ fi
+
++# Check whether user wants TCP wrappers support
++TCPW_MSG="no"
++AC_ARG_WITH([tcp-wrappers],
++ [ --with-tcp-wrappers[[=PATH]] Enable tcpwrappers support (optionally in PATH)],
++ [
++ if test "x$withval" != "xno" ; then
++ saved_LIBS="$LIBS"
++ saved_LDFLAGS="$LDFLAGS"
++ saved_CPPFLAGS="$CPPFLAGS"
++ if test -n "${withval}" && \
++ test "x${withval}" != "xyes"; then
++ if test -d "${withval}/lib"; then
++ if test -n "${need_dash_r}"; then
++ LDFLAGS="-L${withval}/lib -R${withval}/lib ${LDFLAGS}"
++ else
++ LDFLAGS="-L${withval}/lib ${LDFLAGS}"
++ fi
++ else
++ if test -n "${need_dash_r}"; then
++ LDFLAGS="-L${withval} -R${withval} ${LDFLAGS}"
++ else
++ LDFLAGS="-L${withval} ${LDFLAGS}"
++ fi
++ fi
++ if test -d "${withval}/include"; then
++ CPPFLAGS="-I${withval}/include ${CPPFLAGS}"
++ else
++ CPPFLAGS="-I${withval} ${CPPFLAGS}"
++ fi
++ fi
++ LIBS="-lwrap $LIBS"
++ AC_MSG_CHECKING([for libwrap])
++ AC_LINK_IFELSE([AC_LANG_PROGRAM([[
++#include <sys/types.h>
++#include <sys/socket.h>
++#include <netinet/in.h>
++#include <tcpd.h>
++int deny_severity = 0, allow_severity = 0;
++ ]], [[
++ hosts_access(0);
++ ]])], [
++ AC_MSG_RESULT([yes])
++ AC_DEFINE([LIBWRAP], [1],
++ [Define if you want
++ TCP Wrappers support])
++ SSHDLIBS="$SSHDLIBS -lwrap"
++ TCPW_MSG="yes"
++ ], [
++ AC_MSG_ERROR([*** libwrap missing])
++
++ ])
++ LIBS="$saved_LIBS"
++ fi
++ ]
++)
++
+ # Check whether user wants to use ldns
+ LDNS_MSG="no"
+ AC_ARG_WITH(ldns,
+@@ -5653,6 +5709,7 @@ echo " PAM support: $PAM_MSG"
+ echo " OSF SIA support: $SIA_MSG"
+ echo " KerberosV support: $KRB5_MSG"
+ echo " SELinux support: $SELINUX_MSG"
++echo " TCP Wrappers support: $TCPW_MSG"
+ echo " libedit support: $LIBEDIT_MSG"
+ echo " libldns support: $LDNS_MSG"
+ echo " Solaris process contract support: $SPC_MSG"
+diff --git a/sshd.8 b/sshd.8
+index bace97839..71da859dc 100644
+--- a/sshd.8
++++ b/sshd.8
+@@ -910,6 +910,12 @@ the user's home directory becomes accessible.
+ This file should be writable only by the user, and need not be
+ readable by anyone else.
+ .Pp
++.It Pa /etc/hosts.allow
++.It Pa /etc/hosts.deny
++Access controls that should be enforced by tcp-wrappers are defined here.
++Further details are described in
++.Xr hosts_access 5 .
++.Pp
+ .It Pa /etc/hosts.equiv
+ This file is for host-based authentication (see
+ .Xr ssh 1 ) .
+@@ -1012,6 +1018,7 @@ The content of this file is not sensitive; it can be world-readable.
+ .Xr ssh-keygen 1 ,
+ .Xr ssh-keyscan 1 ,
+ .Xr chroot 2 ,
++.Xr hosts_access 5 ,
+ .Xr login.conf 5 ,
+ .Xr moduli 5 ,
+ .Xr sshd_config 5 ,
+diff --git a/sshd.c b/sshd.c
+index 6ad9a845a..7944cf633 100644
+--- a/sshd.c
++++ b/sshd.c
+@@ -129,6 +129,13 @@
+ #include "srclimit.h"
+ #include "dh.h"
+
++#ifdef LIBWRAP
++#include <tcpd.h>
++#include <syslog.h>
++int allow_severity;
++int deny_severity;
++#endif /* LIBWRAP */
++
+ /* Re-exec fds */
+ #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
+ #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
+@@ -2189,6 +2196,24 @@ main(int ac, char **av)
+ #ifdef SSH_AUDIT_EVENTS
+ audit_connection_from(remote_ip, remote_port);
+ #endif
++#ifdef LIBWRAP
++ allow_severity = options.log_facility|LOG_INFO;
++ deny_severity = options.log_facility|LOG_WARNING;
++ /* Check whether logins are denied from this host. */
++ if (ssh_packet_connection_is_on_socket(ssh)) {
++ struct request_info req;
++
++ request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
++ fromhost(&req);
++
++ if (!hosts_access(&req)) {
++ debug("Connection refused by tcp wrapper");
++ refuse(&req);
++ /* NOTREACHED */
++ fatal("libwrap refuse returns");
++ }
++ }
++#endif /* LIBWRAP */
+
+ rdomain = ssh_packet_rdomain_in(ssh);
+