On 1/11/24 15:41, Ken Hornstein wrote:
But here is some snippets of the PKCS#11 code in MIT Kerberos:

When specifying the search parameters to find the private key:

     keytype = CKK_RSA;
     attrs[nattrs].type = CKA_KEY_TYPE;
     attrs[nattrs].pValue = &keytype;
     attrs[nattrs].ulValueLen = sizeof keytype;
     nattrs++;

When setting the key signing mechanism:

     /*
      * We'd like to use CKM_SHA256_RSA_PKCS for signing if it's available, but
      * historically many cards seem to be confused about whether they are
      * capable of mechanisms or not. The safe thing seems to be to ignore the
      * mechanism list, always use CKM_RSA_PKCS and calculate the sha256 digest
      * ourselves.
      */
     id_cryptoctx->mech = CKM_RSA_PKCS;

Those are all hardcoded use of RSA keys and signing mechanisms and it
doesn't handle ECC at all.  So unless the Yubico library ignored the
key type and mechanism (which I think would be extremely unlikely but
not impossible) I suspect you were using RSA back during your original
testing and didn't realize it.

--Ken

Its good to know the reason why MIT Kerberos cannot handle EC certificates right now.

I know that NIST is happy with RSA 2048, but in Europe RSA >= 3072 is already mandatory, and this key size makes small devices like the Yubikeys very slow when generating the keys. In fact, Yubikeys only support RSA <=2048.

So is there a way to submit a feature request for ECDSA support in MIT Kerberos ?

-- Goetz


________________________________________________
Kerberos mailing list           Kerberos@mit.edu
https://mailman.mit.edu/mailman/listinfo/kerberos

Reply via email to