[OE-core] [PATCH] libpam: add a new 'nullok_secure' option support to pam_unix
Saul Wold
sgw at linux.intel.com
Wed Jul 17 16:03:22 UTC 2013
On 07/16/2013 08:15 PM, Ming Liu wrote:
> 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 | 196 +++++++++++++++++
> .../pam/libpam/pam-unix-nullok-secure.patch | 220 ++++++++++++++++++++
Both these patches need proper Upstream-Status: and Signed-off-by: tags
please
Thanks
Sau!
> meta/recipes-extended/pam/libpam_1.1.6.bb | 4 +-
> 3 files changed, 419 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..a537b33
> --- /dev/null
> +++ b/meta/recipes-extended/pam/libpam/pam-security-abstract-securetty-handling.patch
> @@ -0,0 +1,196 @@
> +Description: extract the securetty logic for use with the "nullok_secure" option
> + introduced in the "055_pam_unix_nullok_secure" patch.
> +
> +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..09cffe3
> --- /dev/null
> +++ b/meta/recipes-extended/pam/libpam/pam-unix-nullok-secure.patch
> @@ -0,0 +1,220 @@
> +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: not yet submitted
> +===================================================================
> +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}"
>
>
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