On Mon, Jun 10, 2013 at 04:59:37PM -0400, Richard Guy Briggs wrote: Please find a new patch at the end... Ok, I've used your suggestion, but switching to AC_CHECK_MEMBERS() (and balancing the AC_MSG_WARN() parens). Removed due to feature/side effect of AC_CHECK_MEMBERS(). Removed. I've changed the wording to "Please upgrade your headers/kernel." Thanks for your feedback Dmitry. From: Richard Guy Briggs <rgb(a)redhat.com&gt; Date: Thu, 21 Mar 2013 00:56:51 -0400 Subject: [PATCH] pam_tty_audit: add an option to control logging of passwords: log_passwd Most commands are entered one line at a time and processed as complete lines in non-canonical mode. Commands that interactively require a password, enter canonical mode with echo set to off to do this. This feature (icanon and !echo) can be used to avoid logging passwords by audit while still logging the rest of the command. Adding a member to the struct audit_tty_status passed in by pam_tty_audit allows control of logging passwords per task. This can be used with older kernels since it checks for the needed structure members at compile time. Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- configure.in | 6 ++++++ modules/pam_tty_audit/pam_tty_audit.8.xml | 15 +++++++++++++++ modules/pam_tty_audit/pam_tty_audit.c | 23 ++++++++++++++++++++++- 3 files changed, 43 insertions(+), 1 deletions(-) diff --git a/configure.in b/configure.in index 515b301..b92d9ac 100644 --- a/configure.in +++ b/configure.in @@ -386,6 +386,10 @@ if test x"$WITH_LIBAUDIT" != xno ; then fi if test ! -z "$HAVE_AUDIT_TTY_STATUS" ; then AC_DEFINE([HAVE_AUDIT_TTY_STATUS], 1, [Define to 1 if struct audit_tty_status exists.]) + + AC_CHECK_MEMBERS([struct audit_tty_status.log_passwd], [], + AC_MSG_WARN([audit_tty_status.log_passwd is not available. The log_passwd option is disabled.]), + [[#include <libaudit.h>]]) fi else LIBAUDIT="" @@ -393,6 +397,8 @@ fi AC_SUBST(LIBAUDIT) AM_CONDITIONAL([HAVE_AUDIT_TTY_STATUS], [test "x$HAVE_AUDIT_TTY_STATUS" = xyes]) +AM_CONDITIONAL([HAVE_AUDIT_TTY_STATUS_LOG_PASSWD], + [test "x$ac_cv_member_audit_tty_status_log_passwd" = xyes]) AC_CHECK_HEADERS(xcrypt.h crypt.h) AS_IF([test "x$ac_cv_header_xcrypt_h" = "xyes"], diff --git a/modules/pam_tty_audit/pam_tty_audit.8.xml b/modules/pam_tty_audit/pam_tty_audit.8.xml index 447b845..552353c 100644 --- a/modules/pam_tty_audit/pam_tty_audit.8.xml +++ b/modules/pam_tty_audit/pam_tty_audit.8.xml @@ -77,6 +77,19 @@ </para> </listitem> </varlistentry> + <varlistentry> + <term> + <option>log_passwd</option> + </term> + <listitem> + <para> + Log keystrokes when ECHO mode is off but ICANON mode is active. + This is the mode in which the tty is placed during password entry. + By default, passwords are not logged. This option may not be + available on older kernels (3.9?). + </para> + </listitem> + </varlistentry> </variablelist> </refsect1> @@ -161,6 +174,8 @@ session required pam_tty_audit.so disable=* enable=root <para> pam_tty_audit was written by Miloslav Trma&ccaron; &amp;lt;mitr(a)redhat.com&amp;gt;. + The log_passwd option was added by Richard Guy Briggs + &amp;lt;rgb(a)redhat.com&amp;gt;. </para> </refsect1> diff --git a/modules/pam_tty_audit/pam_tty_audit.c b/modules/pam_tty_audit/pam_tty_audit.c index 080f495..a3b590d 100644 --- a/modules/pam_tty_audit/pam_tty_audit.c +++ b/modules/pam_tty_audit/pam_tty_audit.c @@ -201,6 +201,9 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char **argv) struct audit_tty_status *old_status, new_status; const char *user; int i, fd, open_only; +#ifdef HAVE_AUDIT_TTY_STATUS_LOG_PASSWD + int log_passwd; +#endif /* HAVE_AUDIT_TTY_STATUS_LOG_PASSWD */ (void)flags; @@ -212,6 +215,9 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char **argv) command = CMD_NONE; open_only = 0; +#ifdef HAVE_AUDIT_TTY_STATUS_LOG_PASSWD + log_passwd = 0; +#endif /* HAVE_AUDIT_TTY_STATUS_LOG_PASSWD */ for (i = 0; i < argc; i++) { if (strncmp (argv[i], "enable=", 7) == 0 @@ -237,6 +243,14 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char **argv) } else if (strcmp (argv[i], "open_only") == 0) open_only = 1; + else if (strcmp (argv[i], "log_passwd") == 0) +#ifdef HAVE_AUDIT_TTY_STATUS_LOG_PASSWD + log_passwd = 1; +#else /* HAVE_AUDIT_TTY_STATUS_LOG_PASSWD */ + pam_syslog (pamh, LOG_WARNING, + "The log_passwd option was not available at compile time."); +#warning "pam_tty_audit: The log_passwd option is not available. Please upgrade your headers/kernel." +#endif /* HAVE_AUDIT_TTY_STATUS_LOG_PASSWD */ else { pam_syslog (pamh, LOG_ERR, "unknown option `%s'", argv[i]); @@ -262,7 +276,14 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char **argv) } new_status.enabled = (command == CMD_ENABLE ? 1 : 0); - if (old_status->enabled == new_status.enabled) +#ifdef HAVE_AUDIT_TTY_STATUS_LOG_PASSWD + new_status.log_passwd = log_passwd; +#endif /* HAVE_AUDIT_TTY_STATUS_LOG_PASSWD */ + if (old_status->enabled == new_status.enabled +#ifdef HAVE_AUDIT_TTY_STATUS_LOG_PASSWD + && old_status->log_passwd == new_status.log_passwd +#endif /* HAVE_AUDIT_TTY_STATUS_LOG_PASSWD */ + ) { open_only = 1; /* to clean up old_status */ goto ok_fd; -- 1.7.1 - RGB -- Richard Guy Briggs <rbriggs(a)redhat.com&gt; Senior Software Engineer Kernel Security AMER ENG Base Operating Systems Remote, Ottawa, Canada Voice: 1.647.777.2635 Internal: (81) 32635