Re: [PATCH v2 00/14] Add support for NIST P521 to ecdsa and ecdh

[Simo Sorce]

On Thu, 2024-02-15 at 18:13 -0500, Stefan Berger wrote:
> This series of patches adds support for the NIST P521 curve to ecdsa and
> ecdh. Test cases for NIST P521 are added to both modules.
> 
> An issue with the current code in ecdsa and ecdh is that it assumes that
> input arrays providing key coordinates for example, are arrays of digits
> (a 'digit' is a 'u64'). This works well for all currently supported
> curves, such as NIST P192/256/384, but does not work for NIST P521 where
> coordinates are 8 digits + 2 bytes long. So some of the changes deal with
> converting byte arrays to digits and digits to byte arrays.
> 
> 
> Regards,
>    Stefan
> 
> v2:
>  - Reformulated some patch descriptions
>  - Fixed issue detected by krobot
>  - Some other small changes to the code
> 
> Stefan Berger (14):
>   crypto: ecdsa - Convert byte arrays with key coordinates to digits
>   crypto: ecdsa - Adjust tests on length of key parameters
>   crypto: ecdsa - Extend res.x mod n calculation for NIST P521
>   crypto: ecc - Implement vli_mmod_fast_521 for NIST p521
>   crypto: ecc - For NIST P521 use vli_num_bits to get number of bits
>   crypto: ecc - Add NIST P521 curve parameters
>   crypto: ecdsa - Register NIST P521 and extend test suite
>   x509: Add OID for NIST P521 and extend parser for it
>   crypto: ecdh - Use properly formatted digits to check for valid key
>   crypto: ecc - Implement ecc_digits_to_bytes to convert digits to byte
>     array
>   crypto: Add nbits field to ecc_curve structure
>   crypto: ecc - Implement and use ecc_curve_get_nbytes to get curve's
>     nbytes
>   crypto: ecdh - Use functions to copy digits from and to byte array
>   crypto: ecdh - Add support for NIST P521 and add test case
> 
>  crypto/asymmetric_keys/x509_cert_parser.c |   3 +
>  crypto/ecc.c                              |  71 +++++--
>  crypto/ecc_curve_defs.h                   |  45 +++++
>  crypto/ecdh.c                             |  59 +++++-
>  crypto/ecdsa.c                            |  48 ++++-
>  crypto/testmgr.c                          |  14 ++
>  crypto/testmgr.h                          | 225 ++++++++++++++++++++++
>  include/crypto/ecc_curve.h                |   3 +
>  include/crypto/ecdh.h                     |   1 +
>  include/crypto/internal/ecc.h             |  61 +++++-
>  include/linux/oid_registry.h              |   1 +
>  11 files changed, 495 insertions(+), 36 deletions(-)

Hi Stefan,
what kind of side-channel testing was performed on this code?
And what is the use case you are adding it for?

Thanks,
Simo.

-- 
Simo Sorce
Distinguished Engineer
RHEL Crypto Team
Red Hat, Inc