keygeneration: add ability to generate GSC RW signing key pairs

GSC RW signing requires an 3070 bit RSA key. The codesigner tool when
invoked expects the public key in .pem format, the same format is used
by the RO codebase when incorporating the public key in the RO image.

This patch introduces a new key option, RSA3070_NOSIG_ALGOID. The keys
of this kind are not going to be processed by futility, hence no need
to specify the signing algorithm.

TEST=ran ./ and observed two gsc keys generated:
    $ ls *gsc*

    in the FPGA setup confirmed that Ti50 RW can be signed and
    verified using the generated key pair.

Signed-off-by: Vadim Bendebury <>
Change-Id: Ie676ba8043c34900388372270329a4903656d499
Reviewed-by: Mike Frysinger <>
Commit-Queue: Mike Frysinger <>
2 files changed