pam_authenticate - account authentication

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 via 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.

pam_authenticate - account authentication

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_UNAVAIL 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.

pam_start(3), pam_setcred(3), pam_chauthtok(3), pam_strerror(3), pam(7) Linux-PAM 07/03/2025 PAM_AUTHENTICATE(3)