The Heimdal GSS-API implementation had a bug in releases before 0.6 that made it fail to inter-operate when using DES3 with other GSS-API implementations when using gss_get_mic / gss_verify_mic. Its possible to modify the behavior of the generator of the MIC with the krb5.conf configuration file so that old clients/servers will still work.
New clients/servers will try both the old and new MIC in Heimdal 0.6. In 0.7 it will check only if configured and the compatibility code will be removed in 0.8.
Heimdal 0.6 still generates by default the broken GSS-API DES3 mic, this will change in 0.7 to generate correct des3 mic.
To turn on compatibility with older clients and servers, change the [gssapi] broken_des3_mic in krb5.conf that contains a list of globbing expressions that will be matched against the server name. To turn off generation of the old (incompatible) mic of the MIC use [gssapi] correct_des3_mic.
If a match for a entry is in both [gssapi] correct_des3_mic and [gssapi] correct_des3_mic, the later will override.
This config option modifies behaviour for both clients and servers.
broken_des3_mic = cvs/*@SU.SE
broken_des3_mic = host/*@E.KTH.SE
correct_des3_mic = host/*@SU.SE
All of 0.5.x versions of heimdal had broken token delegations in the client side, the server side was correct.
krb5(3), krb5.conf(5), kerberos(8)