Linux and UNIX Man Pages

Test Your Knowledge in Computers #481
Difficulty: Medium
Generally speaking, programs do not start out as source code.
True or False?
Linux & Unix Commands - Search Man Pages

pam_authenticate(3pam) [opensolaris man page]

pam_authenticate(3PAM)					       PAM Library Functions					    pam_authenticate(3PAM)

pam_authenticate - perform authentication within the PAM framework SYNOPSIS
cc [ flag ... ] file ... -lpam [ library ... ] #include <security/pam_appl.h> int pam_authenticate(pam_handle_t *pamh, int flags); DESCRIPTION
The pam_authenticate() function 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. The user in question should have been speci- fied by a prior call to pam_start() or pam_set_item(). The following flags may be set in the flags field: PAM_SILENT Authentication service should not generate any messages. PAM_DISALLOW_NULL_AUTHTOK The authentication service should return PAM_AUTH_ERR if the user has a null authentication token. RETURN VALUES
Upon successful completion, PAM_SUCCESS is returned. In addition to the error return values described in pam(3PAM), the following values may be returned: PAM_AUTH_ERR Authentication failure. PAM_CRED_INSUFFICIENT Cannot access authentication data due to insufficient credentials. PAM_AUTHINFO_UNAVAIL Underlying authentication service cannot retrieve authentication information. PAM_USER_UNKNOWN User not known to the underlying authentication module. PAM_MAXTRIES An authentication service has maintained a retry count which has been reached. No further retries should be attempted. ATTRIBUTES
See attributes(5) for description of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability | Stable | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe with exceptions | +-----------------------------+-----------------------------+ SEE ALSO
pam(3PAM), pam_open_session(3PAM), pam_set_item(3PAM), pam_setcred(3PAM), pam_start(3PAM), libpam(3LIB), attributes(5) NOTES
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 retry. If the PAM framework cannot load the authentication module, then it will return PAM_ABORT. This indicates a serious failure, and 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 each of 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 be no prompt to the user to enter an authentication token. The interfaces in libpam are MT-Safe only if each thread within the multithreaded application uses its own PAM handle. SunOS 5.11 27 Jan 2005 pam_authenticate(3PAM)

Check Out this Related Man Page

PAM_AUTHENTICATE(3)						 Linux-PAM Manual					       PAM_AUTHENTICATE(3)

pam_authenticate - account authentication SYNOPSIS
#include <security/pam_appl.h> int pam_authenticate(pam_handle_t *pamh, int flags); DESCRIPTION
The pam_authenticate function is used to authenticate the user. The user is required to provide an authentication token depending upon the authentication service, usually this is a password, but could also be a finger print. The PAM service module may request that the user enter their username vio the the conversation mechanism (see pam_start(3) and pam_conv(3)). The name of the authenticated user will be present in the PAM item PAM_USER. This item may be recovered with a call to pam_get_item(3). The pamh argument is an authentication handle obtained by a prior call to pam_start(). The flags argument is the binary or of zero or more of the following values: PAM_SILENT Do not emit any messages. PAM_DISALLOW_NULL_AUTHTOK The PAM module service should return PAM_AUTH_ERR if the user does not have a registered authentication token. RETURN VALUES
PAM_ABORT The application should exit immediately after calling pam_end(3) first. PAM_AUTH_ERR The user was not authenticated. PAM_CRED_INSUFFICIENT For some reason the application does not have sufficient credentials to authenticate the user. PAM_AUTHINFO_UNVAIL The modules were not able to access the authentication information. This might be due to a network or hardware failure etc. PAM_MAXTRIES One or more of the authentication modules has reached its limit of tries authenticating the user. Do not try again. PAM_SUCCESS The user was successfully authenticated. PAM_USER_UNKNOWN User unknown to authentication service. SEE ALSO
pam_start(3), pam_setcred(3), pam_chauthtok(3), pam_strerror(3), pam(7) Linux-PAM Manual 06/04/2011 PAM_AUTHENTICATE(3)

Featured Tech Videos