[OE-core] [PATCH V1] libpam: add a new 'nullok_secure' option support to pam_unix
Ming Liu
ming.liu at windriver.com
Thu Jul 18 02:04:22 UTC 2013
Debian patch to add a new 'nullok_secure' option to pam_unix, which
accepts users with null passwords only when the applicant is connected
from a tty listed in /etc/securetty.
The original pam_unix.so was configured with nullok_secure in
meta/recipes-extended/pam/libpam/pam.d/common-auth, but no such code
exists actually.
The patch set comes from:
http://patch-tracker.debian.org/patch/series/view/pam/1.1.3-7.1/054_pam_security_abstract_securetty_handling
http://patch-tracker.debian.org/patch/series/view/pam/1.1.3-7.1/055_pam_unix_nullok_secure
Signed-off-by: Ming Liu <ming.liu at windriver.com>
---
.../pam-security-abstract-securetty-handling.patch | 200 ++++++++++++++++++
.../pam/libpam/pam-unix-nullok-secure.patch | 222 ++++++++++++++++++++
meta/recipes-extended/pam/libpam_1.1.6.bb | 4 +-
3 files changed, 425 insertions(+), 1 deletions(-)
create mode 100644 meta/recipes-extended/pam/libpam/pam-security-abstract-securetty-handling.patch
create mode 100644 meta/recipes-extended/pam/libpam/pam-unix-nullok-secure.patch
diff --git a/meta/recipes-extended/pam/libpam/pam-security-abstract-securetty-handling.patch b/meta/recipes-extended/pam/libpam/pam-security-abstract-securetty-handling.patch
new file mode 100644
index 0000000..f1834f6
--- /dev/null
+++ b/meta/recipes-extended/pam/libpam/pam-security-abstract-securetty-handling.patch
@@ -0,0 +1,200 @@
+Description: extract the securetty logic for use with the "nullok_secure" option
+ introduced in the "055_pam_unix_nullok_secure" patch.
+
+Upstream-Status: Pending
+
+Signed-off-by: Ming Liu <ming.liu at windriver.com>
+===================================================================
+diff -urpN a/modules/pam_securetty/Makefile.am b/modules/pam_securetty/Makefile.am
+--- a/modules/pam_securetty/Makefile.am 2013-07-05 11:08:23.224483237 +0800
++++ b/modules/pam_securetty/Makefile.am 2013-07-05 11:15:21.304486456 +0800
+@@ -24,6 +24,10 @@ endif
+ securelib_LTLIBRARIES = pam_securetty.la
+ pam_securetty_la_LIBADD = -L$(top_builddir)/libpam -lpam
+
++pam_securetty_la_SOURCES = \
++ pam_securetty.c \
++ tty_secure.c
++
+ if ENABLE_REGENERATE_MAN
+ noinst_DATA = README
+ README: pam_securetty.8.xml
+diff -urpN a/modules/pam_securetty/pam_securetty.c b/modules/pam_securetty/pam_securetty.c
+--- a/modules/pam_securetty/pam_securetty.c 2013-07-05 11:07:50.064483568 +0800
++++ b/modules/pam_securetty/pam_securetty.c 2013-07-05 11:12:23.994483344 +0800
+@@ -1,7 +1,5 @@
+ /* pam_securetty module */
+
+-#define SECURETTY_FILE "/etc/securetty"
+-#define TTY_PREFIX "/dev/"
+ #define CMDLINE_FILE "/proc/cmdline"
+ #define CONSOLEACTIVE_FILE "/sys/class/tty/console/active"
+
+@@ -40,6 +38,9 @@
+ #include <security/pam_modutil.h>
+ #include <security/pam_ext.h>
+
++extern int _pammodutil_tty_secure(const pam_handle_t *pamh,
++ const char *uttyname);
++
+ #define PAM_DEBUG_ARG 0x0001
+ #define PAM_NOCONSOLE_ARG 0x0002
+
+@@ -73,11 +74,7 @@ securetty_perform_check (pam_handle_t *p
+ const char *username;
+ const char *uttyname;
+ const void *void_uttyname;
+- char ttyfileline[256];
+- char ptname[256];
+- struct stat ttyfileinfo;
+ struct passwd *user_pwd;
+- FILE *ttyfile;
+
+ /* log a trail for debugging */
+ if (ctrl & PAM_DEBUG_ARG) {
+@@ -105,50 +102,7 @@ securetty_perform_check (pam_handle_t *p
+ return PAM_SERVICE_ERR;
+ }
+
+- /* The PAM_TTY item may be prefixed with "/dev/" - skip that */
+- if (strncmp(TTY_PREFIX, uttyname, sizeof(TTY_PREFIX)-1) == 0) {
+- uttyname += sizeof(TTY_PREFIX)-1;
+- }
+-
+- if (stat(SECURETTY_FILE, &ttyfileinfo)) {
+- pam_syslog(pamh, LOG_NOTICE, "Couldn't open %s: %m", SECURETTY_FILE);
+- return PAM_SUCCESS; /* for compatibility with old securetty handling,
+- this needs to succeed. But we still log the
+- error. */
+- }
+-
+- if ((ttyfileinfo.st_mode & S_IWOTH) || !S_ISREG(ttyfileinfo.st_mode)) {
+- /* If the file is world writable or is not a
+- normal file, return error */
+- pam_syslog(pamh, LOG_ERR,
+- "%s is either world writable or not a normal file",
+- SECURETTY_FILE);
+- return PAM_AUTH_ERR;
+- }
+-
+- ttyfile = fopen(SECURETTY_FILE,"r");
+- if (ttyfile == NULL) { /* Check that we opened it successfully */
+- pam_syslog(pamh, LOG_ERR, "Error opening %s: %m", SECURETTY_FILE);
+- return PAM_SERVICE_ERR;
+- }
+-
+- if (isdigit(uttyname[0])) {
+- snprintf(ptname, sizeof(ptname), "pts/%s", uttyname);
+- } else {
+- ptname[0] = '\0';
+- }
+-
+- retval = 1;
+-
+- while ((fgets(ttyfileline, sizeof(ttyfileline)-1, ttyfile) != NULL)
+- && retval) {
+- if (ttyfileline[strlen(ttyfileline) - 1] == '\n')
+- ttyfileline[strlen(ttyfileline) - 1] = '\0';
+-
+- retval = ( strcmp(ttyfileline, uttyname)
+- && (!ptname[0] || strcmp(ptname, uttyname)) );
+- }
+- fclose(ttyfile);
++ retval = _pammodutil_tty_secure(pamh, uttyname);
+
+ if (retval && !(ctrl & PAM_NOCONSOLE_ARG)) {
+ FILE *cmdlinefile;
+diff -urpN a/modules/pam_securetty/tty_secure.c b/modules/pam_securetty/tty_secure.c
+--- a/modules/pam_securetty/tty_secure.c 1970-01-01 08:30:00.000000000 +0830
++++ b/modules/pam_securetty/tty_secure.c 2013-07-05 11:14:21.534482900 +0800
+@@ -0,0 +1,90 @@
++/*
++ * A function to determine if a particular line is in /etc/securetty
++ */
++
++
++#define SECURETTY_FILE "/etc/securetty"
++#define TTY_PREFIX "/dev/"
++
++/* This function taken out of pam_securetty by Sam Hartman
++ * <hartmans at debian.org>*/
++/*
++ * by Elliot Lee <sopwith at redhat.com>, Red Hat Software.
++ * July 25, 1996.
++ * Slight modifications AGM. 1996/12/3
++ */
++
++#include <unistd.h>
++#include <sys/types.h>
++#include <sys/stat.h>
++#include <security/pam_modules.h>
++#include <stdarg.h>
++#include <syslog.h>
++#include <sys/syslog.h>
++#include <stdio.h>
++#include <string.h>
++#include <stdlib.h>
++#include <ctype.h>
++#include <security/pam_modutil.h>
++#include <security/pam_ext.h>
++
++extern int _pammodutil_tty_secure(const pam_handle_t *pamh,
++ const char *uttyname);
++
++int _pammodutil_tty_secure(const pam_handle_t *pamh, const char *uttyname)
++{
++ int retval = PAM_AUTH_ERR;
++ char ttyfileline[256];
++ char ptname[256];
++ struct stat ttyfileinfo;
++ FILE *ttyfile;
++ /* The PAM_TTY item may be prefixed with "/dev/" - skip that */
++ if (strncmp(TTY_PREFIX, uttyname, sizeof(TTY_PREFIX)-1) == 0)
++ uttyname += sizeof(TTY_PREFIX)-1;
++
++ if (stat(SECURETTY_FILE, &ttyfileinfo)) {
++ pam_syslog(pamh, LOG_NOTICE, "Couldn't open %s: %m",
++ SECURETTY_FILE);
++ return PAM_SUCCESS; /* for compatibility with old securetty handling,
++ this needs to succeed. But we still log the
++ error. */
++ }
++
++ if ((ttyfileinfo.st_mode & S_IWOTH) || !S_ISREG(ttyfileinfo.st_mode)) {
++ /* If the file is world writable or is not a
++ normal file, return error */
++ pam_syslog(pamh, LOG_ERR,
++ "%s is either world writable or not a normal file",
++ SECURETTY_FILE);
++ return PAM_AUTH_ERR;
++ }
++
++ ttyfile = fopen(SECURETTY_FILE,"r");
++ if(ttyfile == NULL) { /* Check that we opened it successfully */
++ pam_syslog(pamh, LOG_ERR, "Error opening %s: %m", SECURETTY_FILE);
++ return PAM_SERVICE_ERR;
++ }
++
++ if (isdigit(uttyname[0])) {
++ snprintf(ptname, sizeof(ptname), "pts/%s", uttyname);
++ } else {
++ ptname[0] = '\0';
++ }
++
++ retval = 1;
++
++ while ((fgets(ttyfileline,sizeof(ttyfileline)-1, ttyfile) != NULL)
++ && retval) {
++ if(ttyfileline[strlen(ttyfileline) - 1] == '\n')
++ ttyfileline[strlen(ttyfileline) - 1] = '\0';
++ retval = ( strcmp(ttyfileline,uttyname)
++ && (!ptname[0] || strcmp(ptname, uttyname)) );
++ }
++ fclose(ttyfile);
++
++ if(retval) {
++ retval = PAM_AUTH_ERR;
++ }
++
++ return retval;
++}
diff --git a/meta/recipes-extended/pam/libpam/pam-unix-nullok-secure.patch b/meta/recipes-extended/pam/libpam/pam-unix-nullok-secure.patch
new file mode 100644
index 0000000..b285e96
--- /dev/null
+++ b/meta/recipes-extended/pam/libpam/pam-unix-nullok-secure.patch
@@ -0,0 +1,222 @@
+Debian patch to add a new 'nullok_secure' option to pam_unix, which
+accepts users with null passwords only when the applicant is connected
+from a tty listed in /etc/securetty.
+
+Authors: Sam Hartman <hartmans at debian.org>,
+ Steve Langasek <vorlon at debian.org>
+
+Upstream-Status: Pending
+
+Signed-off-by: Ming Liu <ming.liu at windriver.com>
+===================================================================
+diff -urpN a/modules/pam_unix/Makefile.am b/modules/pam_unix/Makefile.am
+--- a/modules/pam_unix/Makefile.am 2013-07-05 09:51:31.014483164 +0800
++++ b/modules/pam_unix/Makefile.am 2013-07-05 10:26:12.884484000 +0800
+@@ -30,7 +30,8 @@ if HAVE_VERSIONING
+ pam_unix_la_LDFLAGS += -Wl,--version-script=$(srcdir)/../modules.map
+ endif
+ pam_unix_la_LIBADD = $(top_builddir)/libpam/libpam.la \
+- @LIBCRYPT@ @LIBSELINUX@ $(NIS_LIBS)
++ @LIBCRYPT@ @LIBSELINUX@ $(NIS_LIBS) \
++ ../pam_securetty/tty_secure.lo
+
+ securelib_LTLIBRARIES = pam_unix.la
+
+diff -urpN a/modules/pam_unix/pam_unix.8 b/modules/pam_unix/pam_unix.8
+--- a/modules/pam_unix/pam_unix.8 2013-07-05 09:52:16.825108201 +0800
++++ b/modules/pam_unix/pam_unix.8 2013-07-05 10:28:34.724483774 +0800
+@@ -220,7 +220,14 @@ A little more extreme than debug\&.
+ .RS 4
+ The default action of this module is to not permit the user access to a service if their official password is blank\&. The
+ \fBnullok\fR
+-argument overrides this default\&.
++argument overrides this default and allows any user with a blank password to access the service\&.
++.RE
++.PP
++\fBnullok_secure\fR
++.RS 4
++The default action of this module is to not permit the user access to a service if their official password is blank\&. The
++\fBnullok_secure\fR
++argument overrides this default and allows any user with a blank password to access the service as long as the value of PAM_TTY is set to one of the values found in /etc/securetty\&.
+ .RE
+ .PP
+ \fBtry_first_pass\fR
+diff -urpN a/modules/pam_unix/pam_unix.8.xml b/modules/pam_unix/pam_unix.8.xml
+--- a/modules/pam_unix/pam_unix.8.xml 2013-07-05 09:52:38.775108523 +0800
++++ b/modules/pam_unix/pam_unix.8.xml 2013-07-05 10:30:23.084483630 +0800
+@@ -135,7 +135,24 @@
+ <para>
+ The default action of this module is to not permit the
+ user access to a service if their official password is blank.
+- The <option>nullok</option> argument overrides this default.
++ The <option>nullok</option> argument overrides this default
++ and allows any user with a blank password to access the
++ service.
++ </para>
++ </listitem>
++ </varlistentry>
++ <varlistentry>
++ <term>
++ <option>nullok_secure</option>
++ </term>
++ <listitem>
++ <para>
++ The default action of this module is to not permit the
++ user access to a service if their official password is blank.
++ The <option>nullok_secure</option> argument overrides this
++ default and allows any user with a blank password to access
++ the service as long as the value of PAM_TTY is set to one of
++ the values found in /etc/securetty.
+ </para>
+ </listitem>
+ </varlistentry>
+diff -urpN a/modules/pam_unix/README b/modules/pam_unix/README
+--- a/modules/pam_unix/README 2013-07-05 09:51:52.205107846 +0800
++++ b/modules/pam_unix/README 2013-07-05 10:27:10.774484537 +0800
+@@ -57,7 +57,16 @@ nullok
+
+ The default action of this module is to not permit the user access to a
+ service if their official password is blank. The nullok argument overrides
+- this default.
++ this default and allows any user with a blank password to access the
++ service.
++
++nullok_secure
++
++ The default action of this module is to not permit the user access to a
++ service if their official password is blank. The nullok_secure argument
++ overrides this default and allows any user with a blank password to access
++ the service as long as the value of PAM_TTY is set to one of the values
++ found in /etc/securetty.
+
+ try_first_pass
+
+diff -urpN a/modules/pam_unix/support.c b/modules/pam_unix/support.c
+--- a/modules/pam_unix/support.c 2013-07-05 09:50:49.134482523 +0800
++++ b/modules/pam_unix/support.c 2013-07-05 09:56:26.924484267 +0800
+@@ -84,14 +84,22 @@ int _set_ctrl(pam_handle_t *pamh, int fl
+ /* now parse the arguments to this module */
+
+ for (; argc-- > 0; ++argv) {
+- int j;
++ int j, sl;
+
+ D(("pam_unix arg: %s", *argv));
+
+ for (j = 0; j < UNIX_CTRLS_; ++j) {
+- if (unix_args[j].token
+- && !strncmp(*argv, unix_args[j].token, strlen(unix_args[j].token))) {
+- break;
++ if (unix_args[j].token) {
++ sl = strlen(unix_args[j].token);
++ if (unix_args[j].token[sl-1] == '=') {
++ /* exclude argument from comparison */
++ if (!strncmp(*argv, unix_args[j].token, sl))
++ break;
++ } else {
++ /* compare full strings */
++ if (!strcmp(*argv, unix_args[j].token))
++ break;
++ }
+ }
+ }
+
+@@ -461,6 +469,7 @@ static int _unix_run_helper_binary(pam_h
+ child = fork();
+ if (child == 0) {
+ int i=0;
++ int nullok = off(UNIX__NONULL, ctrl);
+ struct rlimit rlim;
+ static char *envp[] = { NULL };
+ char *args[] = { NULL, NULL, NULL, NULL };
+@@ -488,7 +497,18 @@ static int _unix_run_helper_binary(pam_h
+ /* exec binary helper */
+ args[0] = strdup(CHKPWD_HELPER);
+ args[1] = x_strdup(user);
+- if (off(UNIX__NONULL, ctrl)) { /* this means we've succeeded */
++
++ if (on(UNIX_NULLOK_SECURE, ctrl)) {
++ const void *uttyname;
++ retval = pam_get_item(pamh, PAM_TTY, &uttyname);
++ if (retval != PAM_SUCCESS || uttyname == NULL
++ || _pammodutil_tty_secure(pamh, (const char *)uttyname) != PAM_SUCCESS)
++ {
++ nullok = 0;
++ }
++ }
++
++ if (nullok) {
+ args[2]=strdup("nullok");
+ } else {
+ args[2]=strdup("nonull");
+@@ -567,6 +587,17 @@ _unix_blankpasswd (pam_handle_t *pamh, u
+ if (on(UNIX__NONULL, ctrl))
+ return 0; /* will fail but don't let on yet */
+
++ if (on(UNIX_NULLOK_SECURE, ctrl)) {
++ int retval2;
++ const void *uttyname;
++ retval2 = pam_get_item(pamh, PAM_TTY, &uttyname);
++ if (retval2 != PAM_SUCCESS || uttyname == NULL)
++ return 0;
++
++ if (_pammodutil_tty_secure(pamh, (const char *)uttyname) != PAM_SUCCESS)
++ return 0;
++ }
++
+ /* UNIX passwords area */
+
+ retval = get_pwd_hash(pamh, name, &pwd, &salt);
+@@ -653,7 +684,8 @@ int _unix_verify_password(pam_handle_t *
+ }
+ }
+ } else {
+- retval = verify_pwd_hash(p, salt, off(UNIX__NONULL, ctrl));
++ retval = verify_pwd_hash(p, salt,
++ _unix_blankpasswd(pamh, ctrl, name));
+ }
+
+ if (retval == PAM_SUCCESS) {
+diff -urpN a/modules/pam_unix/support.h b/modules/pam_unix/support.h
+--- a/modules/pam_unix/support.h 2013-07-05 09:51:10.385107934 +0800
++++ b/modules/pam_unix/support.h 2013-07-05 10:23:54.815107842 +0800
+@@ -90,8 +90,9 @@ typedef struct {
+ password hash algorithms */
+ #define UNIX_BLOWFISH_PASS 26 /* new password hashes will use blowfish */
+ #define UNIX_MIN_PASS_LEN 27 /* min length for password */
++#define UNIX_NULLOK_SECURE 28 /* NULL passwords allowed only on secure ttys */
+ /* -------------- */
+-#define UNIX_CTRLS_ 28 /* number of ctrl arguments defined */
++#define UNIX_CTRLS_ 29 /* number of ctrl arguments defined */
+
+ #define UNIX_DES_CRYPT(ctrl) (off(UNIX_MD5_PASS,ctrl)&&off(UNIX_BIGCRYPT,ctrl)&&off(UNIX_SHA256_PASS,ctrl)&&off(UNIX_SHA512_PASS,ctrl)&&off(UNIX_BLOWFISH_PASS,ctrl))
+
+@@ -109,7 +110,7 @@ static const UNIX_Ctrls unix_args[UNIX_C
+ /* UNIX_NOT_SET_PASS */ {"not_set_pass", _ALL_ON_, 0100},
+ /* UNIX__PRELIM */ {NULL, _ALL_ON_^(0600), 0200},
+ /* UNIX__UPDATE */ {NULL, _ALL_ON_^(0600), 0400},
+-/* UNIX__NONULL */ {NULL, _ALL_ON_, 01000},
++/* UNIX__NONULL */ {NULL, _ALL_ON_^(0x10000000), 0x200},
+ /* UNIX__QUIET */ {NULL, _ALL_ON_, 02000},
+ /* UNIX_USE_AUTHTOK */ {"use_authtok", _ALL_ON_, 04000},
+ /* UNIX_SHADOW */ {"shadow", _ALL_ON_, 010000},
+@@ -127,7 +128,8 @@ static const UNIX_Ctrls unix_args[UNIX_C
+ /* UNIX_SHA512_PASS */ {"sha512", _ALL_ON_^(0260420000), 040000000},
+ /* UNIX_ALGO_ROUNDS */ {"rounds=", _ALL_ON_, 0100000000},
+ /* UNIX_BLOWFISH_PASS */ {"blowfish", _ALL_ON_^(0260420000), 0200000000},
+-/* UNIX_MIN_PASS_LEN */ {"minlen=", _ALL_ON_, 0400000000},
++/* UNIX_MIN_PASS_LEN */ {"minlen=", _ALL_ON_, 0400000000},
++/* UNIX_NULLOK_SECURE */ {"nullok_secure", _ALL_ON_^(0x200), 0x10000000},
+ };
+
+ #define UNIX_DEFAULTS (unix_args[UNIX__NONULL].flag)
+@@ -163,6 +165,9 @@ extern int _unix_read_password(pam_handl
+ ,const char *data_name
+ ,const void **pass);
+
++extern int _pammodutil_tty_secure(const pam_handle_t *pamh,
++ const char *uttyname);
++
+ extern int _unix_run_verify_binary(pam_handle_t *pamh,
+ unsigned int ctrl, const char *user, int *daysleft);
+ #endif /* _PAM_UNIX_SUPPORT_H */
diff --git a/meta/recipes-extended/pam/libpam_1.1.6.bb b/meta/recipes-extended/pam/libpam_1.1.6.bb
index 62ad7b1..3d8999d 100644
--- a/meta/recipes-extended/pam/libpam_1.1.6.bb
+++ b/meta/recipes-extended/pam/libpam_1.1.6.bb
@@ -23,6 +23,8 @@ SRC_URI = "http://linux-pam.org/library/Linux-PAM-${PV}.tar.bz2 \
file://reflect-the-enforce_for_root-semantics-change-in-pam.patch \
file://add-checks-for-crypt-returning-NULL.patch \
file://libpam-fix-for-CVE-2010-4708.patch \
+ file://pam-security-abstract-securetty-handling.patch \
+ file://pam-unix-nullok-secure.patch \
"
SRC_URI[md5sum] = "7b73e58b7ce79ffa321d408de06db2c4"
SRC_URI[sha256sum] = "bab887d6280f47fc3963df3b95735a27a16f0f663636163ddf3acab5f1149fc2"
@@ -39,7 +41,7 @@ EXTRA_OECONF = "--with-db-uniquename=_pam \
CFLAGS_append = " -fPIC "
-PR = "r2"
+PR = "r3"
S = "${WORKDIR}/Linux-PAM-${PV}"
--
1.7.1
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