Go to main content

man pages section 7: Standards, Environments, Macros, Character Sets, and Miscellany

Exit Print View

Updated: Wednesday, August 8, 2018
 
 

pam_unix_cred(7)

Name

pam_unix_cred - PAM user credential authentication module for UNIX

Synopsis

pam_unix_cred.so.1

Description

The pam_unix_cred module implements pam_sm_setcred(3PAM). It provides functions that establish user credential information. It is a module separate from the pam_unix_auth(7) module to allow replacement of the authentication functionality independently from the credential functionality.

The pam_unix_cred module must always be stacked along with whatever authentication module is used to ensure correct credential setting.

Authentication service modules must implement both pam_sm_authenticate() and pam_sm_setcred().

pam_sm_authenticate() in this module always returns PAM_IGNORE.

pam_sm_setcred() initializes the user's project, privilege sets, initializes or updates the user's audit context if it hasn't already been initialized, and sets the process clearance.

The new clearance is set to the lower bound of the current process clearance and the minimum label returned by getuserrange(3TSOL). If these two labels are disjoint, the clearance is set to the greatest lower bound.

The following flags may be set in the flags field:

PAM_ESTABLISH_CRED
PAM_REFRESH_CRED
PAM_REINITIALIZE_CRED

Initializes the user's project to the project specified in PAM_RESOURCE, or if PAM_RESOURCE is not specified, to the user's default project. Establishes the user's privilege sets.

If the audit context is not already initialized and auditing is configured, these flags cause the context to be initialized to that of the user specified in PAM_AUSER (if any) merged with the user specified in PAM_USER and host specified in PAM_RHOST. If PAM_RHOST is not specified, PAM_TTY specifies the local terminal name. Attributing audit to PAM_AUSER and merging PAM_USER is required for correctly attributing auditing when the system entry is performed by another user that can be identified as trustworthy.

If the audit context is already initialized, the PAM_REINITIALIZE_CRED flag merges the current audit context with that of the user specified in PAM_USER. PAM_REINITIALIZE_CRED is useful when a user is assuming a new identity, as with su(8).

PAM_ESTABLISH_CRED
PAM_REINITIALIZE_CRED

Prompt for an "audit record annotation string" for a PAM_USER, who is configured to request audit record annotation.

PAM_DELETE_CRED

This flag has no effect and always returns PAM_SUCCESS.

The following options are interpreted:

debug

Provides syslog(3C) debugging information at the LOG_DEBUG level.

nowarn

Disables any warning messages.

noannotation

Do not prompt for audit record annotation. It is an error to include this option and the annotation_prompt= option.

annotation_prompt=

Provides a prompt string to override the default audit record annotation prompt of Session Annotation:. The prompt string must immediately follow the =. If the string following the = contains white space, it must be surrounded by quotation marks, for example annotation_prompt=My Prompt String. It is an error to include this option and the noannotation option.

Errors

Upon successful completion of pam_sm_setcred(), PAM_SUCCESS is returned. The following error codes are returned upon error:

PAM_CRED_UNAVAIL

Underlying authentication service cannot retrieve user credentials

PAM_CRED_EXPIRED

User credentials have expired

PAM_USER_UNKNOWN

User is unknown to the authentication service

PAM_CRED_ERR

Failure in setting user credentials

PAM_BUF_ERR

Memory buffer error

PAM_SERVICE_ERR

An illegal option

PAM_SYSTEM_ERR

System error

The following values are returned from pam_sm_authenticate():

PAM_IGNORE

Ignores this module regardless of the control flag

Attributes

See attributes(7) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Committed
MT Level
MT-Safe with exceptions

See Also

ssh(1), settaskid(2), syslog(3C), libpam(3LIB), pam(3PAM), pam_set_item(3PAM), pam_sm_authenticate(3PAM), setproject(3PROJECT), getprojent(3PROJECT), nsswitch.conf(5), pam.conf(5), project(5), user_attr(5), attributes(7), labels(7), pam_authtok_check(7), pam_authtok_get(7), pam_authtok_store(7), pam_dhkeys(7), pam_passwd_auth(7), pam_unix_account(7), pam_unix_auth(7), pam_unix_session(7), privileges(7), su(8)

Notes

The interfaces in libpam(3LIB) are MT-Safe only if each thread within the multi-threaded application uses its own PAM handle.

If this module is replaced, the audit context and credential may not be correctly configured.