| From 9bdc197474795f2d000c2bc04f58f7cef8898f21 Mon Sep 17 00:00:00 2001 |
| From: Amarnath Valluri <amarnath.valluri@intel.com> |
| Date: Wed, 15 Jul 2015 13:07:20 +0300 |
| Subject: [PATCH] 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@debian.org>, |
| Steve Langasek <vorlon@debian.org> |
| |
| Upstream-Status: Pending |
| |
| Signed-off-by: Ming Liu <ming.liu@windriver.com> |
| |
| v2: |
| - Forward ported from v1.1.6 to v1.2.1 |
| |
| Signed-off-by: Amarnath Valluri <amarnath.valluri@intel.com> |
| --- |
| modules/pam_unix/Makefile.am | 3 ++- |
| modules/pam_unix/README | 11 ++++++++++- |
| modules/pam_unix/pam_unix.8 | 9 ++++++++- |
| modules/pam_unix/pam_unix.8.xml | 19 ++++++++++++++++++- |
| modules/pam_unix/support.c | 40 +++++++++++++++++++++++++++++++++++----- |
| modules/pam_unix/support.h | 8 ++++++-- |
| 6 files changed, 79 insertions(+), 11 deletions(-) |
| |
| diff --git a/modules/pam_unix/Makefile.am b/modules/pam_unix/Makefile.am |
| index 56ed591..9a372ac 100644 |
| --- a/modules/pam_unix/Makefile.am |
| +++ b/modules/pam_unix/Makefile.am |
| @@ -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 --git a/modules/pam_unix/README b/modules/pam_unix/README |
| index 3935dba..7880d91 100644 |
| --- a/modules/pam_unix/README |
| +++ b/modules/pam_unix/README |
| @@ -67,7 +67,16 @@ 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 --git a/modules/pam_unix/pam_unix.8 b/modules/pam_unix/pam_unix.8 |
| index 339178b..a4bd906 100644 |
| --- a/modules/pam_unix/pam_unix.8 |
| +++ b/modules/pam_unix/pam_unix.8 |
| @@ -92,7 +92,14 @@ Turns off informational messages namely messages about session open and close vi |
| .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 --git a/modules/pam_unix/pam_unix.8.xml b/modules/pam_unix/pam_unix.8.xml |
| index a8b64bb..1ced6f4 100644 |
| --- a/modules/pam_unix/pam_unix.8.xml |
| +++ b/modules/pam_unix/pam_unix.8.xml |
| @@ -159,7 +159,24 @@ |
| <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 --git a/modules/pam_unix/support.c b/modules/pam_unix/support.c |
| index abccd82..2361957 100644 |
| --- a/modules/pam_unix/support.c |
| +++ b/modules/pam_unix/support.c |
| @@ -189,13 +189,22 @@ int _set_ctrl(pam_handle_t *pamh, int flags, int *remember, int *rounds, |
| /* now parse the arguments to this module */ |
| |
| for (; argc-- > 0; ++argv) { |
| + int 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; |
| + } |
| } |
| } |
| |
| @@ -566,6 +575,7 @@ static int _unix_run_helper_binary(pam_handle_t *pamh, const char *passwd, |
| if (child == 0) { |
| static char *envp[] = { NULL }; |
| const char *args[] = { NULL, NULL, NULL, NULL }; |
| + int nullok = off(UNIX__NONULL, ctrl); |
| |
| /* XXX - should really tidy up PAM here too */ |
| |
| @@ -593,7 +603,16 @@ static int _unix_run_helper_binary(pam_handle_t *pamh, const char *passwd, |
| /* exec binary helper */ |
| args[0] = CHKPWD_HELPER; |
| args[1] = 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]="nullok"; |
| } else { |
| args[2]="nonull"; |
| @@ -678,6 +697,17 @@ _unix_blankpasswd (pam_handle_t *pamh, unsigned int ctrl, const char *name) |
| 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); |
| @@ -764,7 +794,7 @@ int _unix_verify_password(pam_handle_t * pamh, const char *name |
| } |
| } |
| } 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 --git a/modules/pam_unix/support.h b/modules/pam_unix/support.h |
| index 3729ce0..43cdbea 100644 |
| --- a/modules/pam_unix/support.h |
| +++ b/modules/pam_unix/support.h |
| @@ -99,8 +99,9 @@ typedef struct { |
| #define UNIX_MIN_PASS_LEN 27 /* min length for password */ |
| #define UNIX_QUIET 28 /* Don't print informational messages */ |
| #define UNIX_DES 29 /* DES, default */ |
| +#define UNIX_NULLOK_SECURE 30 /* NULL passwords allowed only on secure ttys */ |
| /* -------------- */ |
| -#define UNIX_CTRLS_ 30 /* number of ctrl arguments defined */ |
| +#define UNIX_CTRLS_ 31 /* 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)) |
| |
| @@ -118,7 +119,7 @@ static const UNIX_Ctrls unix_args[UNIX_CTRLS_] = |
| /* UNIX_NOT_SET_PASS */ {"not_set_pass", _ALL_ON_, 0100, 0}, |
| /* UNIX__PRELIM */ {NULL, _ALL_ON_^(0600), 0200, 0}, |
| /* UNIX__UPDATE */ {NULL, _ALL_ON_^(0600), 0400, 0}, |
| -/* UNIX__NONULL */ {NULL, _ALL_ON_, 01000, 0}, |
| +/* UNIX__NONULL */ {NULL, _ALL_ON_^(02000000000), 01000, 0}, |
| /* UNIX__QUIET */ {NULL, _ALL_ON_, 02000, 0}, |
| /* UNIX_USE_AUTHTOK */ {"use_authtok", _ALL_ON_, 04000, 0}, |
| /* UNIX_SHADOW */ {"shadow", _ALL_ON_, 010000, 0}, |
| @@ -139,6 +140,7 @@ static const UNIX_Ctrls unix_args[UNIX_CTRLS_] = |
| /* UNIX_MIN_PASS_LEN */ {"minlen=", _ALL_ON_, 0400000000, 0}, |
| /* UNIX_QUIET */ {"quiet", _ALL_ON_, 01000000000, 0}, |
| /* UNIX_DES */ {"des", _ALL_ON_^(0260420000), 0, 1}, |
| +/* UNIX_NULLOK_SECURE */ {"nullok_secure", _ALL_ON_^(01000), 02000000000, 0}, |
| }; |
| |
| #define UNIX_DEFAULTS (unix_args[UNIX__NONULL].flag) |
| @@ -171,6 +173,8 @@ extern int _unix_read_password(pam_handle_t * pamh |
| ,const char *prompt2 |
| ,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); |
| -- |
| 2.1.4 |
| |