Static PKCS_ECDSA_P521_SHA256
pub static PKCS_ECDSA_P521_SHA256: SignatureAlgorithmExpand description
ECDSA signing using the P-521 curves and SHA-256 hashing as per RFC 5758
Note that this algorithm is not widely supported, and is not supported in TLS 1.3.
Only supported with the aws_lc_rs backend.