[rfc][icedtea7] Handle alternative Kerberos credential cache locations

[Elliott Baron]

Hi Max,

On 08/13/2013 08:54 PM, Weijun Wang wrote:
> Hi Elliott
>
> This is a very good feature. Can you contribute it to OpenJDK directly?

Absolutely! I assume security-dev would be the correct list?

>
> One thing I don't understand is the _GNU_SOURCE macro defined.

This is needed in order to use asprintf. If this is problematic, I could 
replace the asprintf usage with a helper function that manually 
allocates and concatenates the strings. At the very least, I will add a 
comment stating that the #define is for asprintf.

>
> Thanks
> Max
>
>
> On 8/14/13 6:07 AM, Elliott Baron wrote:
>> Hi,
>>
>> Kerberos 1.11 introduced a new configuration variable to override the
>> default location of the credential cache at build time. Fedora 18 and up
>> have used this new configuration variable to define an alternate default
>> cache location (/run/user/$UID/krb5cc/tkt). This bug was initially
>> reported against Fedora [1].
>>
>> On Linux and Solaris systems, FileCredentialsCache.getDefaultCacheName()
>> defaults to the previously hard-coded location (/tmp/krb5cc_$UID). This
>> location will be incorrect if Kerberos was built with an alternative
>> credential cache location set. Since this credential cache location can
>> be arbitrary, we need to query the Kerberos API for the correct
>> location. This patch implements this query using a new JNI call, which
>> adds a dependency on libkrb5 for Linux and Solaris systems.
>>
>> This patch was prepared against icedtea7-forest/jdk, changeset
>> afaedb56b499.
>>
>> 2013-08-12  Elliott Baron <ebaron at redhat.com>
>>      * make/sun/security/Makefile: Build krb5/internal/ccache on Linux
>> and Solaris.
>>      *
>> src/share/classes/sun/security/krb5/internal/ccache/FileCredentialsCache.java: 
>>
>> Replace
>>      hard-coded cache location with native call to Kerberos API.
>>      * make/sun/security/krb5/internal/ccache/Makefile: New file; builds
>> JNI wrapper for
>>      needed Kerberos API.
>>      *
>> src/solaris/native/sun/security/krb5/internal/ccache/krb5ccache.c: New
>> file; JNI function
>>      to query default cache location from Kerberos API.
>>
>> Thanks,
>> Elliott
>>
>> [1] https://bugzilla.redhat.com/show_bug.cgi?id=991170
>>

Thanks,
Elliott