def obtain_or_renew_ticket(principal,
password=None,
renew_life=None,
keytab=False):
ctx = krb5.Context()
cc = krb5.CredentialsCache(ctx)
if have_ticket(principal):
try:
tgt = ctx.renew_tgt(principal, cc)
cc.add(tgt)
except krb5.KrbException:
pass
else:
return
if keytab:
keytab = krb5.Keytab(ctx, '/etc/krb5.keytab')
tgt = ctx.obtain_tgt_keytab(principal, keytab, renew_life=renew_life)
else:
tgt = ctx.obtain_tgt_password(principal,
password,
renew_life=renew_life)
if abs((tgt.starttime - datetime.now()).total_seconds()) > 300:
raise krb5.KrbException("Clock skew too great")
cc.add(tgt)
def have_ticket(principal):
ctx = krb5.Context()
cc = krb5.CredentialsCache(ctx)
for i in cc.entries:
if i.client == principal:
return True
return False