There are few Java Cards that do not support ECDSA at all.
Starting with IsoApplet version 00.06, the applet returns whether the card
supports ECDSA or not. This commit uses this information to decider whether to
register ECDSA mechanisms or not.
Use the new features of sc_asn1_put_tag introduced in OpenSC/OpenSC#314.
Additionally, a RSA private key is sent from one large buffer using either extended APDUs or chaining (in compliance to IsoApplet API version 00.05).
It is required to strip excessive zeroes returned by some Java Cards when removeing the ASN1 structural information for PKCS#11 so that the x/y can be calculated by dividing the signature length by 2. However, the leading zero may only be stripped if it is excessive (outside the field length). Otherwise generated signatures are wrong in rare cases (1 out of 256).
See: 189e998486
The IsoApplet requires the host to do the hashes with RSA. OpenSC will
add all hashes that are available in software and will not expect the
card to do the hashing.
Rework the EC key generation mechanism to send the curve parameters to
the card. In earlier versions, the applet had a copy of the curve
parameters and there was a different algorithm reference for every
curve. This is unfeasible when trying to support a larger number of
curves because of size limitations of the applet.
This commit additionally includes some refactorings that should not
change the functionality.