Manual Pages  — KRB5_VERIFY_INIT_CREDS

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 SYNOPSIS DESCRIPTION SEE ALSO

Kerberos 5 Library (libkrb5, -lkrb5)

#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);

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 it's true, the error will be ignored. Note that this use is possible insecure.