Re: [PATCH v4 2/2] certs: Add ECDSA signature verification self-test

[Herbert Xu <herbert@gondor.apana.org.au>]

On Sat, May 11, 2024 at 01:23:54AM -0500, Joachim Vandersmissen wrote:
> v4: FIPS_SIGNATURE_SELFTEST_ECDSA is no longer user-configurable and will
> be set when the dependencies are fulfilled.
> 
> ---8<---
> 
> Commit c27b2d2012e1 ("crypto: testmgr - allow ecdsa-nist-p256 and -p384
> in FIPS mode") enabled support for ECDSA in crypto/testmgr.c. The
> PKCS#7 signature verification API builds upon the KCAPI primitives to
> perform its high-level operations. Therefore, this change in testmgr.c
> also allows ECDSA to be used by the PKCS#7 signature verification API
> (in FIPS mode).
> 
> However, from a FIPS perspective, the PKCS#7 signature verification API
> is a distinct "service" from the KCAPI primitives. This is because the
> PKCS#7 API performs a "full" signature verification, which consists of
> both hashing the data to be verified, and the public key operation.
> On the other hand, the KCAPI primitive does not perform this hashing
> step - it accepts pre-hashed data from the caller and only performs the
> public key operation.
> 
> For this reason, the ECDSA self-tests in crypto/testmgr.c are not
> sufficient to cover ECDSA signature verification offered by the PKCS#7
> API. This is reflected by the self-test already present in this file
> for RSA PKCS#1 v1.5 signature verification.
> 
> The solution is simply to add a second self-test here for ECDSA. P-256
> with SHA-256 hashing was chosen as those parameters should remain
> FIPS-approved for the foreseeable future, while keeping the performance
> impact to a minimum. The ECDSA certificate and PKCS#7 signed data was
> generated using OpenSSL. The input data is identical to the input data
> for the existing RSA self-test.
> 
> Signed-off-by: Joachim Vandersmissen <git@jvdsn.com>
> ---
>  crypto/asymmetric_keys/Kconfig          |  7 ++
>  crypto/asymmetric_keys/Makefile         |  1 +
>  crypto/asymmetric_keys/selftest.c       |  1 +
>  crypto/asymmetric_keys/selftest.h       |  6 ++
>  crypto/asymmetric_keys/selftest_ecdsa.c | 89 +++++++++++++++++++++++++
>  5 files changed, 104 insertions(+)
>  create mode 100644 crypto/asymmetric_keys/selftest_ecdsa.c

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt