KRB5_VERIFY_INIT_CREDS(3)

NAME
krb5_verify_init_creds_opt_init, krb5_verify_init_creds_opt_set_ap_req_nofail, krb5_verify_init_creds - verifies a credential cache is correct by using a local keytab.

LIBRARY
Kerberos 5 Library (libkrb5, -lkrb5)

SYNOPSIS
#include <krb5.h>

struct krb5_verify_init_creds_opt;
void
krb5_verify_init_creds_opt_init(krb5_verify_init_creds_opt *options);
void
krb5_verify_init_creds_opt_set_ap_req_nofail(krb5_verify_init_creds_opt *options, int ap_req_nofail);
krb5_error_code
krb5_verify_init_creds(krb5_context context, krb5_creds *creds, krb5_principal ap_req_server, krb5_ccache *ccache, krb5_verify_init_creds_opt *options);

DESCRIPTION
The krb5_verify_init_creds function verifies the initial tickets with the local keytab to make sure the response of the KDC was spoof-ed.

krb5_verify_init_creds will use principal ap_req_server from the local keytab, if NULL is passed in, the code will guess the local hostname and use that to form host/hostname/GUESSED-REALM-FOR-HOSTNAME. creds is the credential that krb5_verify_init_creds should verify. If ccache is given krb5_verify_init_creds() stores all credentials it fetched from the KDC there, otherwise it will use a memory credential cache that is destroyed when done.

krb5_verify_init_creds_opt_init() cleans the the structure, must be used before trying to pass it in to krb5_verify_init_creds().

krb5_verify_init_creds_opt_set_ap_req_nofail() controls controls the behavior if ap_req_server doesn't exists in the local keytab or in the KDC's database, if its true, the error will be ignored. Note that this use is possible insecure.

SEE ALSO
krb5(3,) krb5_init_creds(3), krb5_verify_user(3), krb5.conf(5)