diff options
Diffstat (limited to 'debian/patches/restore-tcp-wrappers.patch')
| -rw-r--r-- | debian/patches/restore-tcp-wrappers.patch | 172 |
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..7388fad --- /dev/null +++ b/debian/patches/restore-tcp-wrappers.patch @@ -0,0 +1,172 @@ +From 6806b85f30244d186206004386a9faddc16b8738 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: 2019-06-05 + +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 c8a96deb4..bb435ec1f 100644 +--- a/configure.ac ++++ b/configure.ac +@@ -1571,6 +1571,62 @@ 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, +@@ -5536,6 +5592,7 @@ 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 " MD5 password support: $MD5_MSG" + echo " libedit support: $LIBEDIT_MSG" + echo " libldns support: $LDNS_MSG" +diff --git a/sshd.8 b/sshd.8 +index b2fad56d3..97d547ffa 100644 +--- a/sshd.8 ++++ b/sshd.8 +@@ -900,6 +900,12 @@ 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 ) . +@@ -1002,6 +1008,7 @@ 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 8c5d5822e..a50ec3584 100644 +--- a/sshd.c ++++ b/sshd.c +@@ -124,6 +124,13 @@ + #include "ssherr.h" + #include "sk-api.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) +@@ -2183,6 +2190,24 @@ 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); + |