App-DocKnot
view release on metacpan or search on metacpan
t/data/generate/pam-krb5/docknot.yaml view on Meta::CPAN
login account required /usr/local/lib/security/pam_krb5.so minimum_uid=100
login account required /usr/lib/security/pam_unix_account.so.1
login session required /usr/local/lib/security/pam_krb5.so retain_after_close minimum_uid=100
login session required /usr/lib/security/pam_unix_session.so.1
```
A similar configuration could be used for other services, such as ssh.
See the pam.conf(5) man page for more information. When using this
module with Solaris login (at least on Solaris 8 and 9), you will
probably also need to add `retain_after_close` to the PAM configuration
to avoid having the user's credentials deleted before they are logged
in.
The Solaris Kerberos library reportedly does not support prompting for a
password change of an expired account during authentication. Supporting
password change for expired accounts on Solaris with native Kerberos may
therefore require setting the `defer_pwchange` or `force_pwchange`
option for selected login applications. See the description and
warnings about that option in the pam_krb5(5) man page.
Some configuration options may be put in the `krb5.conf` file used by
t/data/generate/pam-krb5/docknot.yaml view on Meta::CPAN
logging from the module and should provide a trace of exactly what
failed and any available error information.
Many Kerberos authentication problems are due to configuration issues in
`krb5.conf`. If pam-krb5 doesn't work, first check that `kinit` works
on the same system. That will test your basic Kerberos configuration.
If the system has a keytab file installed that's readable by the process
doing authentication via PAM, make sure that the keytab is current and
contains a key for `host/<system>` where <system> is the fully-qualified
hostname. pam-krb5 prevents KDC spoofing by checking the user's
credentials when possible, but this means that if a keytab is present it
must be correct or authentication will fail. You can check the keytab
with `klist -k` and `kinit -k`.
Be sure that all libraries and modules, including PAM modules, loaded by
a program use the same Kerberos libraries. Sometimes programs that use
PAM, such as current versions of OpenSSH, also link against Kerberos
directly. If your sshd is linked against one set of Kerberos libraries
and pam-krb5 is linked against a different set of Kerberos libraries,
this will often cause problems (such as segmentation faults, bus errors,
assertions, or other strange behavior). Similar issues apply to the
t/data/generate/pam-krb5/docknot.yaml view on Meta::CPAN
followed by closing the open PAM session. The corresponding `pam_sm_*`
functions in this module are called when an application calls those
public interface functions. Not all applications call all of those
functions, or in particularly that order, although `pam_authenticate` is
always first and has to be.
When `pam_authenticate` is called, pam-krb5 creates a temporary ticket
cache in `/tmp` and sets the PAM environment variable `PAM_KRB5CCNAME`
to point to it. This ticket cache will be automatically destroyed when
the PAM session is closed and is there only to pass the initial
credentials to the call to `pam_setcred`. The module would use a memory
cache, but memory caches will only work if the application preserves the
PAM environment between the calls to `pam_authenticate` and
`pam_setcred`. Most do, but OpenSSH notoriously does not and calls
`pam_authenticate` in a subprocess, so this method is used to pass the
tickets to the `pam_setcred` call in a different process.
`pam_authenticate` does a complete authentication, including checking
the resulting TGT by obtaining a service ticket for the local host if
possible, but this requires read access to the system keytab. If the
keytab doesn't exist, can't be read, or doesn't include the appropriate
credentials, the default is to accept the authentication. This can be
controlled by setting `verify_ap_req_nofail` to true in `[libdefaults]`
in `/etc/krb5.conf`. `pam_authenticate` also does a basic authorization
check, by default calling `krb5_kuserok` (which uses `~/.k5login` if
available and falls back to checking that the principal corresponds to
the account name). This can be customized with several options
documented in the pam_krb5(5) man page.
pam-krb5 treats `pam_open_session` and `pam_setcred(PAM_ESTABLISH_CRED)`
as synonymous, as some applications call one and some call the other.
Both copy the initial credentials from the temporary cache into a
permanent cache for this session and set `KRB5CCNAME` in the
environment. It will remember when the credential cache has been
established and then avoid doing any duplicate work afterwards, since
some applications call `pam_setcred` or `pam_open_session` multiple
times (most notably X.Org 7 and earlier xdm, which also throws away the
module settings the last time it calls them).
`pam_acct_mgmt` finds the ticket cache, reads it in to obtain the
authenticated principal, and then does is another authorization check
against `.k5login` or the local account name as described above.
t/data/generate/pam-krb5/docknot.yaml view on Meta::CPAN
pam_authenticate
pam_setcred(PAM_REINITIALIZE_CRED)
pam_acct_mgmt
```
(`PAM_REFRESH_CRED` may be used instead.) Authentication proceeds as
above. At the `pam_setcred` stage, rather than creating a new ticket
cache, the module instead finds the current ticket cache (from the
`KRB5CCNAME` environment variable or the default ticket cache location
from the Kerberos library) and then reinitializes it with the
credentials from the temporary `pam_authenticate` ticket cache. When
refreshing a ticket cache, the application should not open a session.
Calling `pam_acct_mgmt` is optional; pam-krb5 doesn't do anything
different when it's called in this case.
If `pam_authenticate` apparently didn't succeed, or if an account was
configured to be ignored via `ignore_root` or `minimum_uid`,
`pam_setcred` (and therefore `pam_open_session`) and `pam_acct_mgmt`
return `PAM_IGNORE`, which tells the PAM library to proceed as if that
module wasn't listed in the PAM configuration at all.
`pam_authenticate`, however, returns failure in the ignored user case by
t/data/generate/pam-krb5/docknot.yaml view on Meta::CPAN
implement. In this case, the calling sequence is:
```
pam_authenticate
pam_acct_mgmt
pam_chauthtok
pam_setcred
pam_open_session
```
During the first `pam_authenticate`, we can't obtain credentials and
therefore a ticket cache since the password is expired. But
`pam_authenticate` isn't called again after `pam_chauthtok`, so
`pam_chauthtok` has to create a ticket cache. We however don't want it
to do this for the normal password change (`passwd`) case.
What we do is set a flag in our PAM data structure saying that we're
processing an expired password, and `pam_chauthtok`, if it sees that
flag, redoes the authentication with password prompting disabled after
it finishes changing the password.
t/data/generate/pam-krb5/docknot.yaml view on Meta::CPAN
> other 2 copied from), it was extremely helpful to look over their code
> which aided in my design.
The module was then patched for the FreeBSD ports collection with
additional modifications by unknown maintainers and then was modified by
Joel Kociolek <joko@logidee.com> to be usable with Debian GNU/Linux.
It was packaged by Sam Hartman as the Kerberos v5 PAM module for Debian
and improved and modified by him and later by Russ Allbery to fix bugs
and add additional features. It was then adopted by Andres Salomon, who
added support for refreshing credentials.
The current distribution is maintained by Russ Allbery, who also added
support for reading configuration from `krb5.conf`, added many features
for compatibility with the Sourceforge module, commented and
standardized the formatting of the code, and overhauled the
documentation.
Thanks to Douglas E. Engert for the initial implementation of PKINIT
support. I have since modified and reworked it extensively, so any bugs
or compilation problems are my fault.
t/data/generate/pam-krb5/output/readme view on Meta::CPAN
login auth required /usr/lib/security/pam_unix_auth.so.1 use_first_pass
login account required /usr/local/lib/security/pam_krb5.so minimum_uid=100
login account required /usr/lib/security/pam_unix_account.so.1
login session required /usr/local/lib/security/pam_krb5.so retain_after_close minimum_uid=100
login session required /usr/lib/security/pam_unix_session.so.1
A similar configuration could be used for other services, such as ssh.
See the pam.conf(5) man page for more information. When using this
module with Solaris login (at least on Solaris 8 and 9), you will
probably also need to add retain_after_close to the PAM configuration to
avoid having the user's credentials deleted before they are logged in.
The Solaris Kerberos library reportedly does not support prompting for a
password change of an expired account during authentication. Supporting
password change for expired accounts on Solaris with native Kerberos may
therefore require setting the defer_pwchange or force_pwchange option
for selected login applications. See the description and warnings about
that option in the pam_krb5(5) man page.
Some configuration options may be put in the krb5.conf file used by your
Kerberos libraries (usually /etc/krb5.conf or /usr/local/etc/krb5.conf)
t/data/generate/pam-krb5/output/readme view on Meta::CPAN
module and should provide a trace of exactly what failed and any
available error information.
Many Kerberos authentication problems are due to configuration issues in
krb5.conf. If pam-krb5 doesn't work, first check that kinit works on
the same system. That will test your basic Kerberos configuration. If
the system has a keytab file installed that's readable by the process
doing authentication via PAM, make sure that the keytab is current and
contains a key for host/<system> where <system> is the fully-qualified
hostname. pam-krb5 prevents KDC spoofing by checking the user's
credentials when possible, but this means that if a keytab is present it
must be correct or authentication will fail. You can check the keytab
with klist -k and kinit -k.
Be sure that all libraries and modules, including PAM modules, loaded by
a program use the same Kerberos libraries. Sometimes programs that use
PAM, such as current versions of OpenSSH, also link against Kerberos
directly. If your sshd is linked against one set of Kerberos libraries
and pam-krb5 is linked against a different set of Kerberos libraries,
this will often cause problems (such as segmentation faults, bus errors,
assertions, or other strange behavior). Similar issues apply to the
t/data/generate/pam-krb5/output/readme view on Meta::CPAN
followed by closing the open PAM session. The corresponding pam_sm_*
functions in this module are called when an application calls those
public interface functions. Not all applications call all of those
functions, or in particularly that order, although pam_authenticate is
always first and has to be.
When pam_authenticate is called, pam-krb5 creates a temporary ticket
cache in /tmp and sets the PAM environment variable PAM_KRB5CCNAME to
point to it. This ticket cache will be automatically destroyed when the
PAM session is closed and is there only to pass the initial credentials
to the call to pam_setcred. The module would use a memory cache, but
memory caches will only work if the application preserves the PAM
environment between the calls to pam_authenticate and pam_setcred. Most
do, but OpenSSH notoriously does not and calls pam_authenticate in a
subprocess, so this method is used to pass the tickets to the
pam_setcred call in a different process.
pam_authenticate does a complete authentication, including checking the
resulting TGT by obtaining a service ticket for the local host if
possible, but this requires read access to the system keytab. If the
keytab doesn't exist, can't be read, or doesn't include the appropriate
credentials, the default is to accept the authentication. This can be
controlled by setting verify_ap_req_nofail to true in [libdefaults] in
/etc/krb5.conf. pam_authenticate also does a basic authorization check,
by default calling krb5_kuserok (which uses ~/.k5login if available and
falls back to checking that the principal corresponds to the account
name). This can be customized with several options documented in the
pam_krb5(5) man page.
pam-krb5 treats pam_open_session and pam_setcred(PAM_ESTABLISH_CRED) as
synonymous, as some applications call one and some call the other. Both
copy the initial credentials from the temporary cache into a permanent
cache for this session and set KRB5CCNAME in the environment. It will
remember when the credential cache has been established and then avoid
doing any duplicate work afterwards, since some applications call
pam_setcred or pam_open_session multiple times (most notably X.Org 7 and
earlier xdm, which also throws away the module settings the last time it
calls them).
pam_acct_mgmt finds the ticket cache, reads it in to obtain the
authenticated principal, and then does is another authorization check
against .k5login or the local account name as described above.
t/data/generate/pam-krb5/output/readme view on Meta::CPAN
pam_authenticate
pam_setcred(PAM_REINITIALIZE_CRED)
pam_acct_mgmt
(PAM_REFRESH_CRED may be used instead.) Authentication proceeds as
above. At the pam_setcred stage, rather than creating a new ticket
cache, the module instead finds the current ticket cache (from the
KRB5CCNAME environment variable or the default ticket cache location
from the Kerberos library) and then reinitializes it with the
credentials from the temporary pam_authenticate ticket cache. When
refreshing a ticket cache, the application should not open a session.
Calling pam_acct_mgmt is optional; pam-krb5 doesn't do anything
different when it's called in this case.
If pam_authenticate apparently didn't succeed, or if an account was
configured to be ignored via ignore_root or minimum_uid, pam_setcred
(and therefore pam_open_session) and pam_acct_mgmt return PAM_IGNORE,
which tells the PAM library to proceed as if that module wasn't listed
in the PAM configuration at all. pam_authenticate, however, returns
failure in the ignored user case by default, since otherwise a
t/data/generate/pam-krb5/output/readme view on Meta::CPAN
The defer_pwchange option is unfortunately somewhat tricky to implement.
In this case, the calling sequence is:
pam_authenticate
pam_acct_mgmt
pam_chauthtok
pam_setcred
pam_open_session
During the first pam_authenticate, we can't obtain credentials and
therefore a ticket cache since the password is expired. But
pam_authenticate isn't called again after pam_chauthtok, so
pam_chauthtok has to create a ticket cache. We however don't want it to
do this for the normal password change (passwd) case.
What we do is set a flag in our PAM data structure saying that we're
processing an expired password, and pam_chauthtok, if it sees that flag,
redoes the authentication with password prompting disabled after it
finishes changing the password.
t/data/generate/pam-krb5/output/readme view on Meta::CPAN
other 2 copied from), it was extremely helpful to look over their code
which aided in my design.
The module was then patched for the FreeBSD ports collection with
additional modifications by unknown maintainers and then was modified by
Joel Kociolek <joko@logidee.com> to be usable with Debian GNU/Linux.
It was packaged by Sam Hartman as the Kerberos v5 PAM module for Debian
and improved and modified by him and later by Russ Allbery to fix bugs
and add additional features. It was then adopted by Andres Salomon, who
added support for refreshing credentials.
The current distribution is maintained by Russ Allbery, who also added
support for reading configuration from krb5.conf, added many features
for compatibility with the Sourceforge module, commented and
standardized the formatting of the code, and overhauled the
documentation.
Thanks to Douglas E. Engert for the initial implementation of PKINIT
support. I have since modified and reworked it extensively, so any bugs
or compilation problems are my fault.
t/data/generate/pam-krb5/output/readme-md view on Meta::CPAN
login account required /usr/local/lib/security/pam_krb5.so minimum_uid=100
login account required /usr/lib/security/pam_unix_account.so.1
login session required /usr/local/lib/security/pam_krb5.so retain_after_close minimum_uid=100
login session required /usr/lib/security/pam_unix_session.so.1
```
A similar configuration could be used for other services, such as ssh.
See the pam.conf(5) man page for more information. When using this module
with Solaris login (at least on Solaris 8 and 9), you will probably also
need to add `retain_after_close` to the PAM configuration to avoid having
the user's credentials deleted before they are logged in.
The Solaris Kerberos library reportedly does not support prompting for a
password change of an expired account during authentication. Supporting
password change for expired accounts on Solaris with native Kerberos may
therefore require setting the `defer_pwchange` or `force_pwchange` option
for selected login applications. See the description and warnings about
that option in the pam_krb5(5) man page.
Some configuration options may be put in the `krb5.conf` file used by your
Kerberos libraries (usually `/etc/krb5.conf` or
t/data/generate/pam-krb5/output/readme-md view on Meta::CPAN
module and should provide a trace of exactly what failed and any available
error information.
Many Kerberos authentication problems are due to configuration issues in
`krb5.conf`. If pam-krb5 doesn't work, first check that `kinit` works on
the same system. That will test your basic Kerberos configuration. If
the system has a keytab file installed that's readable by the process
doing authentication via PAM, make sure that the keytab is current and
contains a key for `host/<system>` where <system> is the fully-qualified
hostname. pam-krb5 prevents KDC spoofing by checking the user's
credentials when possible, but this means that if a keytab is present it
must be correct or authentication will fail. You can check the keytab
with `klist -k` and `kinit -k`.
Be sure that all libraries and modules, including PAM modules, loaded by a
program use the same Kerberos libraries. Sometimes programs that use PAM,
such as current versions of OpenSSH, also link against Kerberos directly.
If your sshd is linked against one set of Kerberos libraries and pam-krb5
is linked against a different set of Kerberos libraries, this will often
cause problems (such as segmentation faults, bus errors, assertions, or
other strange behavior). Similar issues apply to the com_err library or
t/data/generate/pam-krb5/output/readme-md view on Meta::CPAN
followed by closing the open PAM session. The corresponding `pam_sm_*`
functions in this module are called when an application calls those public
interface functions. Not all applications call all of those functions, or
in particularly that order, although `pam_authenticate` is always first
and has to be.
When `pam_authenticate` is called, pam-krb5 creates a temporary ticket
cache in `/tmp` and sets the PAM environment variable `PAM_KRB5CCNAME` to
point to it. This ticket cache will be automatically destroyed when the
PAM session is closed and is there only to pass the initial credentials to
the call to `pam_setcred`. The module would use a memory cache, but
memory caches will only work if the application preserves the PAM
environment between the calls to `pam_authenticate` and `pam_setcred`.
Most do, but OpenSSH notoriously does not and calls `pam_authenticate` in
a subprocess, so this method is used to pass the tickets to the
`pam_setcred` call in a different process.
`pam_authenticate` does a complete authentication, including checking the
resulting TGT by obtaining a service ticket for the local host if
possible, but this requires read access to the system keytab. If the
keytab doesn't exist, can't be read, or doesn't include the appropriate
credentials, the default is to accept the authentication. This can be
controlled by setting `verify_ap_req_nofail` to true in `[libdefaults]` in
`/etc/krb5.conf`. `pam_authenticate` also does a basic authorization
check, by default calling `krb5_kuserok` (which uses `~/.k5login` if
available and falls back to checking that the principal corresponds to the
account name). This can be customized with several options documented in
the pam_krb5(5) man page.
pam-krb5 treats `pam_open_session` and `pam_setcred(PAM_ESTABLISH_CRED)`
as synonymous, as some applications call one and some call the other.
Both copy the initial credentials from the temporary cache into a
permanent cache for this session and set `KRB5CCNAME` in the environment.
It will remember when the credential cache has been established and then
avoid doing any duplicate work afterwards, since some applications call
`pam_setcred` or `pam_open_session` multiple times (most notably X.Org 7
and earlier xdm, which also throws away the module settings the last time
it calls them).
`pam_acct_mgmt` finds the ticket cache, reads it in to obtain the
authenticated principal, and then does is another authorization check
against `.k5login` or the local account name as described above.
t/data/generate/pam-krb5/output/readme-md view on Meta::CPAN
```
pam_authenticate
pam_setcred(PAM_REINITIALIZE_CRED)
pam_acct_mgmt
```
(`PAM_REFRESH_CRED` may be used instead.) Authentication proceeds as
above. At the `pam_setcred` stage, rather than creating a new ticket
cache, the module instead finds the current ticket cache (from the
`KRB5CCNAME` environment variable or the default ticket cache location
from the Kerberos library) and then reinitializes it with the credentials
from the temporary `pam_authenticate` ticket cache. When refreshing a
ticket cache, the application should not open a session. Calling
`pam_acct_mgmt` is optional; pam-krb5 doesn't do anything different when
it's called in this case.
If `pam_authenticate` apparently didn't succeed, or if an account was
configured to be ignored via `ignore_root` or `minimum_uid`, `pam_setcred`
(and therefore `pam_open_session`) and `pam_acct_mgmt` return
`PAM_IGNORE`, which tells the PAM library to proceed as if that module
wasn't listed in the PAM configuration at all. `pam_authenticate`,
t/data/generate/pam-krb5/output/readme-md view on Meta::CPAN
In this case, the calling sequence is:
```
pam_authenticate
pam_acct_mgmt
pam_chauthtok
pam_setcred
pam_open_session
```
During the first `pam_authenticate`, we can't obtain credentials and
therefore a ticket cache since the password is expired. But
`pam_authenticate` isn't called again after `pam_chauthtok`, so
`pam_chauthtok` has to create a ticket cache. We however don't want it to
do this for the normal password change (`passwd`) case.
What we do is set a flag in our PAM data structure saying that we're
processing an expired password, and `pam_chauthtok`, if it sees that flag,
redoes the authentication with password prompting disabled after it
finishes changing the password.
t/data/generate/pam-krb5/output/readme-md view on Meta::CPAN
> authors originally wrote the first module the other 2 copied from), it
> was extremely helpful to look over their code which aided in my design.
The module was then patched for the FreeBSD ports collection with
additional modifications by unknown maintainers and then was modified by
Joel Kociolek <joko@logidee.com> to be usable with Debian GNU/Linux.
It was packaged by Sam Hartman as the Kerberos v5 PAM module for Debian
and improved and modified by him and later by Russ Allbery to fix bugs and
add additional features. It was then adopted by Andres Salomon, who added
support for refreshing credentials.
The current distribution is maintained by Russ Allbery, who also added
support for reading configuration from `krb5.conf`, added many features
for compatibility with the Sourceforge module, commented and standardized
the formatting of the code, and overhauled the documentation.
Thanks to Douglas E. Engert for the initial implementation of PKINIT
support. I have since modified and reworked it extensively, so any bugs
or compilation problems are my fault.
t/data/update/pam-krb5/docknot.yaml view on Meta::CPAN
login account required /usr/local/lib/security/pam_krb5.so minimum_uid=100
login account required /usr/lib/security/pam_unix_account.so.1
login session required /usr/local/lib/security/pam_krb5.so retain_after_close minimum_uid=100
login session required /usr/lib/security/pam_unix_session.so.1
```
A similar configuration could be used for other services, such as ssh.
See the pam.conf(5) man page for more information. When using this module
with Solaris login (at least on Solaris 8 and 9), you will probably also
need to add `retain_after_close` to the PAM configuration to avoid having
the user's credentials deleted before they are logged in.
The Solaris Kerberos library reportedly does not support prompting for a
password change of an expired account during authentication. Supporting
password change for expired accounts on Solaris with native Kerberos may
therefore require setting the `defer_pwchange` or `force_pwchange` option
for selected login applications. See the description and warnings about
that option in the pam_krb5(5) man page.
Some configuration options may be put in the `krb5.conf` file used by your
Kerberos libraries (usually `/etc/krb5.conf` or
t/data/update/pam-krb5/docknot.yaml view on Meta::CPAN
module and should provide a trace of exactly what failed and any available
error information.
Many Kerberos authentication problems are due to configuration issues in
`krb5.conf`. If pam-krb5 doesn't work, first check that `kinit` works on
the same system. That will test your basic Kerberos configuration. If
the system has a keytab file installed that's readable by the process
doing authentication via PAM, make sure that the keytab is current and
contains a key for `host/<system>` where <system> is the fully-qualified
hostname. pam-krb5 prevents KDC spoofing by checking the user's
credentials when possible, but this means that if a keytab is present it
must be correct or authentication will fail. You can check the keytab
with `klist -k` and `kinit -k`.
Be sure that all libraries and modules, including PAM modules, loaded by a
program use the same Kerberos libraries. Sometimes programs that use PAM,
such as current versions of OpenSSH, also link against Kerberos directly.
If your sshd is linked against one set of Kerberos libraries and pam-krb5
is linked against a different set of Kerberos libraries, this will often
cause problems (such as segmentation faults, bus errors, assertions, or
other strange behavior). Similar issues apply to the com_err library or
t/data/update/pam-krb5/docknot.yaml view on Meta::CPAN
followed by closing the open PAM session. The corresponding `pam_sm_*`
functions in this module are called when an application calls those public
interface functions. Not all applications call all of those functions, or
in particularly that order, although `pam_authenticate` is always first
and has to be.
When `pam_authenticate` is called, pam-krb5 creates a temporary ticket
cache in `/tmp` and sets the PAM environment variable `PAM_KRB5CCNAME` to
point to it. This ticket cache will be automatically destroyed when the
PAM session is closed and is there only to pass the initial credentials to
the call to `pam_setcred`. The module would use a memory cache, but
memory caches will only work if the application preserves the PAM
environment between the calls to `pam_authenticate` and `pam_setcred`.
Most do, but OpenSSH notoriously does not and calls `pam_authenticate` in
a subprocess, so this method is used to pass the tickets to the
`pam_setcred` call in a different process.
`pam_authenticate` does a complete authentication, including checking the
resulting TGT by obtaining a service ticket for the local host if
possible, but this requires read access to the system keytab. If the
keytab doesn't exist, can't be read, or doesn't include the appropriate
credentials, the default is to accept the authentication. This can be
controlled by setting `verify_ap_req_nofail` to true in `[libdefaults]` in
`/etc/krb5.conf`. `pam_authenticate` also does a basic authorization
check, by default calling `krb5_kuserok` (which uses `~/.k5login` if
available and falls back to checking that the principal corresponds to the
account name). This can be customized with several options documented in
the pam_krb5(5) man page.
pam-krb5 treats `pam_open_session` and `pam_setcred(PAM_ESTABLISH_CRED)`
as synonymous, as some applications call one and some call the other.
Both copy the initial credentials from the temporary cache into a
permanent cache for this session and set `KRB5CCNAME` in the environment.
It will remember when the credential cache has been established and then
avoid doing any duplicate work afterwards, since some applications call
`pam_setcred` or `pam_open_session` multiple times (most notably X.Org 7
and earlier xdm, which also throws away the module settings the last time
it calls them).
`pam_acct_mgmt` finds the ticket cache, reads it in to obtain the
authenticated principal, and then does is another authorization check
against `.k5login` or the local account name as described above.
t/data/update/pam-krb5/docknot.yaml view on Meta::CPAN
```
pam_authenticate
pam_setcred(PAM_REINITIALIZE_CRED)
pam_acct_mgmt
```
(`PAM_REFRESH_CRED` may be used instead.) Authentication proceeds as
above. At the `pam_setcred` stage, rather than creating a new ticket
cache, the module instead finds the current ticket cache (from the
`KRB5CCNAME` environment variable or the default ticket cache location
from the Kerberos library) and then reinitializes it with the credentials
from the temporary `pam_authenticate` ticket cache. When refreshing a
ticket cache, the application should not open a session. Calling
`pam_acct_mgmt` is optional; pam-krb5 doesn't do anything different when
it's called in this case.
If `pam_authenticate` apparently didn't succeed, or if an account was
configured to be ignored via `ignore_root` or `minimum_uid`, `pam_setcred`
(and therefore `pam_open_session`) and `pam_acct_mgmt` return
`PAM_IGNORE`, which tells the PAM library to proceed as if that module
wasn't listed in the PAM configuration at all. `pam_authenticate`,
t/data/update/pam-krb5/docknot.yaml view on Meta::CPAN
In this case, the calling sequence is:
```
pam_authenticate
pam_acct_mgmt
pam_chauthtok
pam_setcred
pam_open_session
```
During the first `pam_authenticate`, we can't obtain credentials and
therefore a ticket cache since the password is expired. But
`pam_authenticate` isn't called again after `pam_chauthtok`, so
`pam_chauthtok` has to create a ticket cache. We however don't want it to
do this for the normal password change (`passwd`) case.
What we do is set a flag in our PAM data structure saying that we're
processing an expired password, and `pam_chauthtok`, if it sees that flag,
redoes the authentication with password prompting disabled after it
finishes changing the password.
t/data/update/pam-krb5/docknot.yaml view on Meta::CPAN
> authors originally wrote the first module the other 2 copied from), it
> was extremely helpful to look over their code which aided in my design.
The module was then patched for the FreeBSD ports collection with
additional modifications by unknown maintainers and then was modified by
Joel Kociolek <joko@logidee.com> to be usable with Debian GNU/Linux.
It was packaged by Sam Hartman as the Kerberos v5 PAM module for Debian
and improved and modified by him and later by Russ Allbery to fix bugs and
add additional features. It was then adopted by Andres Salomon, who added
support for refreshing credentials.
The current distribution is maintained by Russ Allbery, who also added
support for reading configuration from `krb5.conf`, added many features
for compatibility with the Sourceforge module, commented and standardized
the formatting of the code, and overhauled the documentation.
Thanks to Douglas E. Engert for the initial implementation of PKINIT
support. I have since modified and reworked it extensively, so any bugs
or compilation problems are my fault.
t/data/update/pam-krb5/old/sections/configuring view on Meta::CPAN
login account required /usr/local/lib/security/pam_krb5.so minimum_uid=100
login account required /usr/lib/security/pam_unix_account.so.1
login session required /usr/local/lib/security/pam_krb5.so retain_after_close minimum_uid=100
login session required /usr/lib/security/pam_unix_session.so.1
```
A similar configuration could be used for other services, such as ssh.
See the pam.conf(5) man page for more information. When using this module
with Solaris login (at least on Solaris 8 and 9), you will probably also
need to add `retain_after_close` to the PAM configuration to avoid having
the user's credentials deleted before they are logged in.
The Solaris Kerberos library reportedly does not support prompting for a
password change of an expired account during authentication. Supporting
password change for expired accounts on Solaris with native Kerberos may
therefore require setting the `defer_pwchange` or `force_pwchange` option
for selected login applications. See the description and warnings about
that option in the pam_krb5(5) man page.
Some configuration options may be put in the `krb5.conf` file used by your
Kerberos libraries (usually `/etc/krb5.conf` or
t/data/update/pam-krb5/old/sections/debugging view on Meta::CPAN
module and should provide a trace of exactly what failed and any available
error information.
Many Kerberos authentication problems are due to configuration issues in
`krb5.conf`. If pam-krb5 doesn't work, first check that `kinit` works on
the same system. That will test your basic Kerberos configuration. If
the system has a keytab file installed that's readable by the process
doing authentication via PAM, make sure that the keytab is current and
contains a key for `host/<system>` where <system> is the fully-qualified
hostname. pam-krb5 prevents KDC spoofing by checking the user's
credentials when possible, but this means that if a keytab is present it
must be correct or authentication will fail. You can check the keytab
with `klist -k` and `kinit -k`.
Be sure that all libraries and modules, including PAM modules, loaded by a
program use the same Kerberos libraries. Sometimes programs that use PAM,
such as current versions of OpenSSH, also link against Kerberos directly.
If your sshd is linked against one set of Kerberos libraries and pam-krb5
is linked against a different set of Kerberos libraries, this will often
cause problems (such as segmentation faults, bus errors, assertions, or
other strange behavior). Similar issues apply to the com_err library or
t/data/update/pam-krb5/old/sections/history-and-acknowledgements view on Meta::CPAN
> authors originally wrote the first module the other 2 copied from), it
> was extremely helpful to look over their code which aided in my design.
The module was then patched for the FreeBSD ports collection with
additional modifications by unknown maintainers and then was modified by
Joel Kociolek <joko@logidee.com> to be usable with Debian GNU/Linux.
It was packaged by Sam Hartman as the Kerberos v5 PAM module for Debian
and improved and modified by him and later by Russ Allbery to fix bugs and
add additional features. It was then adopted by Andres Salomon, who added
support for refreshing credentials.
The current distribution is maintained by Russ Allbery, who also added
support for reading configuration from `krb5.conf`, added many features
for compatibility with the Sourceforge module, commented and standardized
the formatting of the code, and overhauled the documentation.
Thanks to Douglas E. Engert for the initial implementation of PKINIT
support. I have since modified and reworked it extensively, so any bugs
or compilation problems are my fault.
t/data/update/pam-krb5/old/sections/implementation-notes view on Meta::CPAN
followed by closing the open PAM session. The corresponding `pam_sm_*`
functions in this module are called when an application calls those public
interface functions. Not all applications call all of those functions, or
in particularly that order, although `pam_authenticate` is always first
and has to be.
When `pam_authenticate` is called, pam-krb5 creates a temporary ticket
cache in `/tmp` and sets the PAM environment variable `PAM_KRB5CCNAME` to
point to it. This ticket cache will be automatically destroyed when the
PAM session is closed and is there only to pass the initial credentials to
the call to `pam_setcred`. The module would use a memory cache, but
memory caches will only work if the application preserves the PAM
environment between the calls to `pam_authenticate` and `pam_setcred`.
Most do, but OpenSSH notoriously does not and calls `pam_authenticate` in
a subprocess, so this method is used to pass the tickets to the
`pam_setcred` call in a different process.
`pam_authenticate` does a complete authentication, including checking the
resulting TGT by obtaining a service ticket for the local host if
possible, but this requires read access to the system keytab. If the
keytab doesn't exist, can't be read, or doesn't include the appropriate
credentials, the default is to accept the authentication. This can be
controlled by setting `verify_ap_req_nofail` to true in `[libdefaults]` in
`/etc/krb5.conf`. `pam_authenticate` also does a basic authorization
check, by default calling `krb5_kuserok` (which uses `~/.k5login` if
available and falls back to checking that the principal corresponds to the
account name). This can be customized with several options documented in
the pam_krb5(5) man page.
pam-krb5 treats `pam_open_session` and `pam_setcred(PAM_ESTABLISH_CRED)`
as synonymous, as some applications call one and some call the other.
Both copy the initial credentials from the temporary cache into a
permanent cache for this session and set `KRB5CCNAME` in the environment.
It will remember when the credential cache has been established and then
avoid doing any duplicate work afterwards, since some applications call
`pam_setcred` or `pam_open_session` multiple times (most notably X.Org 7
and earlier xdm, which also throws away the module settings the last time
it calls them).
`pam_acct_mgmt` finds the ticket cache, reads it in to obtain the
authenticated principal, and then does is another authorization check
against `.k5login` or the local account name as described above.
t/data/update/pam-krb5/old/sections/implementation-notes view on Meta::CPAN
```
pam_authenticate
pam_setcred(PAM_REINITIALIZE_CRED)
pam_acct_mgmt
```
(`PAM_REFRESH_CRED` may be used instead.) Authentication proceeds as
above. At the `pam_setcred` stage, rather than creating a new ticket
cache, the module instead finds the current ticket cache (from the
`KRB5CCNAME` environment variable or the default ticket cache location
from the Kerberos library) and then reinitializes it with the credentials
from the temporary `pam_authenticate` ticket cache. When refreshing a
ticket cache, the application should not open a session. Calling
`pam_acct_mgmt` is optional; pam-krb5 doesn't do anything different when
it's called in this case.
If `pam_authenticate` apparently didn't succeed, or if an account was
configured to be ignored via `ignore_root` or `minimum_uid`, `pam_setcred`
(and therefore `pam_open_session`) and `pam_acct_mgmt` return
`PAM_IGNORE`, which tells the PAM library to proceed as if that module
wasn't listed in the PAM configuration at all. `pam_authenticate`,
t/data/update/pam-krb5/old/sections/implementation-notes view on Meta::CPAN
In this case, the calling sequence is:
```
pam_authenticate
pam_acct_mgmt
pam_chauthtok
pam_setcred
pam_open_session
```
During the first `pam_authenticate`, we can't obtain credentials and
therefore a ticket cache since the password is expired. But
`pam_authenticate` isn't called again after `pam_chauthtok`, so
`pam_chauthtok` has to create a ticket cache. We however don't want it to
do this for the normal password change (`passwd`) case.
What we do is set a flag in our PAM data structure saying that we're
processing an expired password, and `pam_chauthtok`, if it sees that flag,
redoes the authentication with password prompting disabled after it
finishes changing the password.
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