Function init [src]

Create an blind key pair from an existing key pair, a blinding seed and a context.

Prototype

 pub fn init(key_pair: Ed25519.KeyPair, blind_seed: [blind_seed_length]u8, ctx: []const u8) (NonCanonicalError || IdentityElementError)!BlindKeyPair

Parameters

key_pair: Ed25519.KeyPairblind_seed: [blind_seed_length]u8ctx: []const u8

Source

  pub fn init(key_pair: Ed25519.KeyPair, blind_seed: [blind_seed_length]u8, ctx: []const u8) (NonCanonicalError || IdentityElementError)!BlindKeyPair {
    var h: [Sha512.digest_length]u8 = undefined;
    Sha512.hash(&key_pair.secret_key.seed(), &h, .{});
    Curve.scalar.clamp(h[0..32]);
    const scalar = Curve.scalar.reduce(h[0..32].*);

    const blind_h = blindCtx(blind_seed, ctx);
    const blind_factor = Curve.scalar.reduce(blind_h[0..32].*);

    const blind_scalar = Curve.scalar.mul(scalar, blind_factor);
    const blind_public_key = BlindPublicKey{
        .key = try PublicKey.fromBytes((Curve.basePoint.mul(blind_scalar) catch return error.IdentityElement).toBytes()),
    };

    var prefix: [64]u8 = undefined;
    prefix[0..32].* = h[32..64].*;
    prefix[32..64].* = blind_h[32..64].*;

    const blind_secret_key = BlindSecretKey{
        .prefix = prefix,
        .blind_scalar = blind_scalar,
        .blind_public_key = blind_public_key,
    };
    return BlindKeyPair{
        .blind_public_key = blind_public_key,
        .blind_secret_key = blind_secret_key,
    };
}  