NAME [Toc] [Back]
pam_authenticate - perform authentication within the PAM framework
SYNOPSIS [Toc] [Back]
cc [ flag ... ] file ... -lpam [ library ... ]
int pam_authenticate(pam_handle_t *pamh, int flags);
DESCRIPTION [Toc] [Back]
pam_authenticate() is called to authenticate the current user. The
user is usually required to enter a password or similar authentication
token depending upon the authentication service configured within the
system. In the case of smart card authentication this token would be a
PIN (Personal Identification Number). The user in question should
have been specified by a prior call to pam_start() or pam_set_item().
The following flags may be set in the flags field:
PAM_SILENT [Toc] [Back]
Authentication service should not generate any messages
PAM_DISALLOW_NULL_AUTHTOK [Toc] [Back]
The authentication service should return PAM_AUTH_ERROR if
the user has a null authentication token
APPLICATION USAGE [Toc] [Back]
Refer to pam(3) for information on thread-safety of PAM interfaces.
NOTES [Toc] [Back]
In the case of authentication failures due to an incorrect username or
password, it is the responsibility of the application to retry
pam_authenticate() and to maintain the retry count. An authentication
service module may implement an internal retry count and return an
error PAM_MAXTRIES if the module does not want the application to
If the PAM framework can not load the authentication module, then it
will return PAM_ABORT. This indicates a serious failure and that the
application should not attempt to retry the authentication.
For security reasons, the location of authentication failures is
hidden from the user. Thus, if several authentication services are
stacked and a single service fails, pam_authenticate() requires that
the user re-authenticate to all the services.
A null authentication token in the authentication database will result
in successful authentication unless PAM_DISALLOW_NULL_AUTHTOK was
specified. In such cases, there will not be any prompting for the
user to enter an authentication token.
Hewlett-Packard Company - 1 - HP-UX 11i Version 2: August 2003
The authentication can be done through a smart card. In this case the
user plugs their smart card in the smart card reader and is required
to enter their smart card PIN.
RETURN VALUES [Toc] [Back]
Upon successful completion, PAM_SUCCESS is returned. In addition to
the error return values described in pam(3), the following values may
PAM_AUTH_ERR Authentication failure.
PAM_CRED_INSUFFICIENT Can not access authentication data due
to insufficient credentials.
PAM_AUTHINFO_UNAVAIL Underlying authentication service can
not retrieve authentication
PAM_USER_UNKNOWN User not known to the underlying
PAM_MAXTRIES An authentication service has
maintained a retry count which has
been reached. No further retries
should be attempted.
SEE ALSO [Toc] [Back]
pam(3), pam_start(3), pam_open_session(3), pam_setcred(3).
Hewlett-Packard Company - 2 - HP-UX 11i Version 2: August 2003 [ Back ]