krb5_c_is_keyed_cksum() is a boolean function. It cannot safely return an error value. Change the error condition to return False (0) instead of 0xFFFFFFFF. To generate a diff of this commit: cvs diff -r5.173 -r5.174 krb5/src/lib/crypto/ChangeLog cvs diff -r5.6 -r5.7 krb5/src/lib/crypto/keyed_cksum.c