pam_authenticate 3 Linux-PAM Manual pam_authenticate account authentication #include <security/pam_appl.h> int pam_authenticate pam_handle_t *pamh int flags 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_start3 and pam_conv3 ). 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_item3 . 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_ABORT The application should exit immediately after calling pam_end3 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_start3 , pam_setcred3 , pam_chauthtok3 , pam_strerror3 , pam8