From b0ec5d1e472a0cd74972bfe9575dcf6a3d0cad1c Mon Sep 17 00:00:00 2001 From: "Dmitry V. Levin" Date: Fri, 24 Jan 2014 15:32:08 +0000 Subject: Introduce pam_modutil_sanitize_helper_fds This change introduces pam_modutil_sanitize_helper_fds - a new function that redirects standard descriptors and closes all other descriptors. pam_modutil_sanitize_helper_fds supports three types of input and output redirection: - PAM_MODUTIL_IGNORE_FD: do not redirect at all. - PAM_MODUTIL_PIPE_FD: redirect to a pipe. For stdin, it is implemented by creating a pipe, closing its write end, and redirecting stdin to its read end. Likewise, for stdout/stderr it is implemented by creating a pipe, closing its read end, and redirecting to its write end. Unlike stdin redirection, stdout/stderr redirection to a pipe has a side effect that a process writing to such descriptor should be prepared to handle SIGPIPE appropriately. - PAM_MODUTIL_NULL_FD: redirect to /dev/null. For stdin, it is implemented via PAM_MODUTIL_PIPE_FD because there is no functional difference. For stdout/stderr, it is classic redirection to /dev/null. PAM_MODUTIL_PIPE_FD is usually more suitable due to linux kernel security restrictions, but when the helper process might be writing to the corresponding descriptor and termination of the helper process by SIGPIPE is not desirable, one should choose PAM_MODUTIL_NULL_FD. * libpam/pam_modutil_sanitize.c: New file. * libpam/Makefile.am (libpam_la_SOURCES): Add it. * libpam/include/security/pam_modutil.h (pam_modutil_redirect_fd, pam_modutil_sanitize_helper_fds): New declarations. * libpam/libpam.map (LIBPAM_MODUTIL_1.1.9): New interface. * modules/pam_exec/pam_exec.c (call_exec): Use pam_modutil_sanitize_helper_fds. * modules/pam_mkhomedir/pam_mkhomedir.c (create_homedir): Likewise. * modules/pam_unix/pam_unix_acct.c (_unix_run_verify_binary): Likewise. * modules/pam_unix/pam_unix_passwd.c (_unix_run_update_binary): Likewise. * modules/pam_unix/support.c (_unix_run_helper_binary): Likewise. * modules/pam_xauth/pam_xauth.c (run_coprocess): Likewise. * modules/pam_unix/support.h (MAX_FD_NO): Remove. --- libpam/include/security/pam_modutil.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'libpam/include') diff --git a/libpam/include/security/pam_modutil.h b/libpam/include/security/pam_modutil.h index 8087ba15..4ce8c552 100644 --- a/libpam/include/security/pam_modutil.h +++ b/libpam/include/security/pam_modutil.h @@ -129,6 +129,19 @@ extern int PAM_NONNULL((1,2)) pam_modutil_regain_priv(pam_handle_t *pamh, struct pam_modutil_privs *p); +enum pam_modutil_redirect_fd { + PAM_MODUTIL_IGNORE_FD, /* do not redirect */ + PAM_MODUTIL_PIPE_FD, /* redirect to a pipe */ + PAM_MODUTIL_NULL_FD, /* redirect to /dev/null */ +}; + +/* redirect standard descriptors, close all other descriptors. */ +extern int PAM_NONNULL((1)) +pam_modutil_sanitize_helper_fds(pam_handle_t *pamh, + enum pam_modutil_redirect_fd redirect_stdin, + enum pam_modutil_redirect_fd redirect_stdout, + enum pam_modutil_redirect_fd redirect_stderr); + #ifdef __cplusplus } #endif -- cgit v1.2.3 From a684595c0bbd88df71285f43fb27630e3829121e Mon Sep 17 00:00:00 2001 From: Thorsten Kukuk Date: Tue, 29 Mar 2016 14:14:03 +0200 Subject: Remove "--enable-static-modules" option and support from Linux-PAM. It was never official supported and was broken since years. * configure.ac: Remove --enable-static-modules option. * doc/man/pam_sm_acct_mgmt.3.xml: Remove PAM_EXTERN. * doc/man/pam_sm_authenticate.3.xml: Likewise. * doc/man/pam_sm_chauthtok.3.xml: Likewise. * doc/man/pam_sm_close_session.3.xml: Likewise. * doc/man/pam_sm_open_session.3.xml: Likewise. * doc/man/pam_sm_setcred.3.xml: Likewise. * libpam/Makefile.am: Remove STATIC_MODULES cases. * libpam/include/security/pam_modules.h: Remove PAM_STATIC parts. * libpam/pam_dynamic.c: Likewise. * libpam/pam_handlers.c: Likewise. * libpam/pam_private.h: Likewise. * libpam/pam_static.c: Remove file. * libpam/pam_static_modules.h: Remove header file. * modules/pam_access/pam_access.c: Remove PAM_EXTERN and PAM_STATIC parts. * modules/pam_cracklib/pam_cracklib.c: Likewise. * modules/pam_debug/pam_debug.c: Likewise. * modules/pam_deny/pam_deny.c: Likewise. * modules/pam_echo/pam_echo.c: Likewise. * modules/pam_env/pam_env.c: Likewise. * modules/pam_exec/pam_exec.c: Likewise. * modules/pam_faildelay/pam_faildelay.c: Likewise. * modules/pam_filter/pam_filter.c: Likewise. * modules/pam_ftp/pam_ftp.c: Likewise. * modules/pam_group/pam_group.c: Likewise. * modules/pam_issue/pam_issue.c: Likewise. * modules/pam_keyinit/pam_keyinit.c: Likewise. * modules/pam_lastlog/pam_lastlog.c: Likewise. * modules/pam_limits/pam_limits.c: Likewise. * modules/pam_listfile/pam_listfile.c: Likewise. * modules/pam_localuser/pam_localuser.c: Likewise. * modules/pam_loginuid/pam_loginuid.c: Likewise. * modules/pam_mail/pam_mail.c: Likewise. * modules/pam_mkhomedir/pam_mkhomedir.c: Likewise. * modules/pam_motd/pam_motd.c: Likewise. * modules/pam_namespace/pam_namespace.c: Likewise. * modules/pam_nologin/pam_nologin.c: Likewise. * modules/pam_permit/pam_permit.c: Likewise. * modules/pam_pwhistory/pam_pwhistory.c: Likewise. * modules/pam_rhosts/pam_rhosts.c: Likewise. * modules/pam_rootok/pam_rootok.c: Likewise. * modules/pam_securetty/pam_securetty.c: Likewise. * modules/pam_selinux/pam_selinux.c: Likewise. * modules/pam_sepermit/pam_sepermit.c: Likewise. * modules/pam_shells/pam_shells.c: Likewise. * modules/pam_stress/pam_stress.c: Likewise. * modules/pam_succeed_if/pam_succeed_if.c: Likewise. * modules/pam_tally/pam_tally.c: Likewise. * modules/pam_tally2/pam_tally2.c: Likewise. * modules/pam_time/pam_time.c: Likewise. * modules/pam_timestamp/pam_timestamp.c: Likewise. * modules/pam_tty_audit/pam_tty_audit.c: Likewise. * modules/pam_umask/pam_umask.c: Likewise. * modules/pam_userdb/pam_userdb.c: Likewise. * modules/pam_warn/pam_warn.c: Likewise. * modules/pam_wheel/pam_wheel.c: Likewise. * modules/pam_xauth/pam_xauth.c: Likewise. * modules/pam_unix/Makefile.am: Remove STATIC_MODULES part. * modules/pam_unix/pam_unix_acct.c: Remove PAM_STATIC part. * modules/pam_unix/pam_unix_auth.c: Likewise. * modules/pam_unix/pam_unix_passwd.c: Likewise. * modules/pam_unix/pam_unix_sess.c: Likewise. * modules/pam_unix/pam_unix_static.c: Removed. * modules/pam_unix/pam_unix_static.h: Removed. * po/POTFILES.in: Remove removed files. * tests/tst-dlopen.c: Remove PAM_STATIC part. --- libpam/include/security/pam_modules.h | 78 ++++++----------------------------- 1 file changed, 12 insertions(+), 66 deletions(-) (limited to 'libpam/include') diff --git a/libpam/include/security/pam_modules.h b/libpam/include/security/pam_modules.h index 5c516c4e..37568e99 100644 --- a/libpam/include/security/pam_modules.h +++ b/libpam/include/security/pam_modules.h @@ -30,80 +30,26 @@ pam_get_data(const pam_handle_t *pamh, const char *module_data_name, extern int PAM_NONNULL((1,2)) pam_get_user(pam_handle_t *pamh, const char **user, const char *prompt); -#ifdef PAM_STATIC - -#define PAM_EXTERN static - -struct pam_module { - const char *name; /* Name of the module */ - - /* These are function pointers to the module's key functions. */ - - int (*pam_sm_authenticate)(pam_handle_t *pamh, int flags, - int argc, const char **argv); - int (*pam_sm_setcred)(pam_handle_t *pamh, int flags, - int argc, const char **argv); - int (*pam_sm_acct_mgmt)(pam_handle_t *pamh, int flags, - int argc, const char **argv); - int (*pam_sm_open_session)(pam_handle_t *pamh, int flags, - int argc, const char **argv); - int (*pam_sm_close_session)(pam_handle_t *pamh, int flags, - int argc, const char **argv); - int (*pam_sm_chauthtok)(pam_handle_t *pamh, int flags, - int argc, const char **argv); -}; - -#else /* !PAM_STATIC */ - -#define PAM_EXTERN extern - -#endif /* PAM_STATIC */ - -/* Lots of files include pam_modules.h that don't need these - * declared. However, when they are declared static, they - * need to be defined later. So we have to protect C files - * that include these without wanting these functions defined.. */ - -#if (defined(PAM_STATIC) && defined(PAM_SM_AUTH)) || !defined(PAM_STATIC) - /* Authentication API's */ -PAM_EXTERN int pam_sm_authenticate(pam_handle_t *pamh, int flags, - int argc, const char **argv); -PAM_EXTERN int pam_sm_setcred(pam_handle_t *pamh, int flags, - int argc, const char **argv); - -#endif /*(defined(PAM_STATIC) && defined(PAM_SM_AUTH)) - || !defined(PAM_STATIC)*/ - -#if (defined(PAM_STATIC) && defined(PAM_SM_ACCOUNT)) || !defined(PAM_STATIC) +int pam_sm_authenticate(pam_handle_t *pamh, int flags, + int argc, const char **argv); +int pam_sm_setcred(pam_handle_t *pamh, int flags, + int argc, const char **argv); /* Account Management API's */ -PAM_EXTERN int pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, - int argc, const char **argv); - -#endif /*(defined(PAM_STATIC) && defined(PAM_SM_ACCOUNT)) - || !defined(PAM_STATIC)*/ - -#if (defined(PAM_STATIC) && defined(PAM_SM_SESSION)) || !defined(PAM_STATIC) +int pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, + int argc, const char **argv); /* Session Management API's */ -PAM_EXTERN int pam_sm_open_session(pam_handle_t *pamh, int flags, - int argc, const char **argv); - -PAM_EXTERN int pam_sm_close_session(pam_handle_t *pamh, int flags, - int argc, const char **argv); +int pam_sm_open_session(pam_handle_t *pamh, int flags, + int argc, const char **argv); -#endif /*(defined(PAM_STATIC) && defined(PAM_SM_SESSION)) - || !defined(PAM_STATIC)*/ - -#if (defined(PAM_STATIC) && defined(PAM_SM_PASSWORD)) || !defined(PAM_STATIC) +int pam_sm_close_session(pam_handle_t *pamh, int flags, + int argc, const char **argv); /* Password Management API's */ -PAM_EXTERN int pam_sm_chauthtok(pam_handle_t *pamh, int flags, - int argc, const char **argv); - -#endif /*(defined(PAM_STATIC) && defined(PAM_SM_PASSWORD)) - || !defined(PAM_STATIC)*/ +int pam_sm_chauthtok(pam_handle_t *pamh, int flags, + int argc, const char **argv); /* The following two flags are for use across the Linux-PAM/module * interface only. The Application is not permitted to use these -- cgit v1.2.3 From 6b12a20c527cb6ced5b8911ea0f1dcdfc6e6f30c Mon Sep 17 00:00:00 2001 From: Thorsten Kukuk Date: Tue, 29 Mar 2016 14:17:34 +0200 Subject: PAM_EXTERN isn't needed anymore, but don't remove it to not break lot of external code using it. * libpam/include/security/pam_modules.h: Readd PAM_EXTERN for compatibility --- libpam/include/security/pam_modules.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'libpam/include') diff --git a/libpam/include/security/pam_modules.h b/libpam/include/security/pam_modules.h index 37568e99..ec65e3e9 100644 --- a/libpam/include/security/pam_modules.h +++ b/libpam/include/security/pam_modules.h @@ -75,6 +75,9 @@ int pam_sm_chauthtok(pam_handle_t *pamh, int flags, #define PAM_DATA_REPLACE 0x20000000 /* used when replacing a data item */ +/* PAM_EXTERN isn't needed anymore, but don't remove it to not break + lot of external code using it. */ +#define PAM_EXTERN extern /* take care of any compatibility issues */ #include -- cgit v1.2.3