verify_ecdsa

fn verify_ecdsa(
    comptime Hash: type,
    message: []const u8,
    encoded_sig: []const u8,
    pub_key_algo: Parsed.PubKeyAlgo,
    sec1_pub_key: []const u8,
) !void {
    const sig_named_curve = switch (pub_key_algo) {
        .X9_62_id_ecPublicKey => |named_curve| named_curve,
        else => return error.CertificateSignatureAlgorithmMismatch,
    };

    switch (sig_named_curve) {
        .secp521r1 => {
            return error.CertificateSignatureNamedCurveUnsupported;
        },
        inline .X9_62_prime256v1,
        .secp384r1,
        => |curve| {
            const Ecdsa = crypto.sign.ecdsa.Ecdsa(curve.Curve(), Hash);
            const sig = Ecdsa.Signature.fromDer(encoded_sig) catch |err| switch (err) {
                error.InvalidEncoding => return error.CertificateSignatureInvalid,
            };
            const pub_key = Ecdsa.PublicKey.fromSec1(sec1_pub_key) catch |err| switch (err) {
                error.InvalidEncoding => return error.CertificateSignatureInvalid,
                error.NonCanonical => return error.CertificateSignatureInvalid,
                error.NotSquare => return error.CertificateSignatureInvalid,
            };
            sig.verify(message, pub_key) catch |err| switch (err) {
                error.IdentityElement => return error.CertificateSignatureInvalid,
                error.NonCanonical => return error.CertificateSignatureInvalid,
                error.SignatureVerificationFailed => return error.CertificateSignatureInvalid,
            };
        },
    }
}