/// <summary>
/// 创建私钥
/// </summary>
/// <param name="outPrivateKey">用于存放私钥的缓冲区</param>
unsafe public static void CreatePrivateKey(Span <byte> outPrivateKey)
{
if (outPrivateKey.Length < 32)
{
throw new ArgumentException("缓冲区至少要32字节", nameof(outPrivateKey));
}
var privateKey = outPrivateKey.Slice(0, 32);
U256 k;
do
{
rng.GetBytes(privateKey);
k = new U256(privateKey, bigEndian: true);
} while (k.IsZero || k >= U256N.N);
}
/// <summary>
/// 根据私钥创建公钥
/// </summary>
/// <param name="privateKey"></param>
/// <returns></returns>
unsafe public static PublicKey CreatePublicKey(ReadOnlySpan <byte> privateKey)
{
if (privateKey.Length != 32)
{
throw new InvalidPrivateKeyException("私钥长度必须是32字节");
}
var k = new U256(privateKey, bigEndian: true);
if (k.IsZero || k >= U256N.N)
{
throw new InvalidPrivateKeyException();
}
var retPoint = (Point)EllipticCurve.MulG(k);
return(new PublicKey(retPoint.X, retPoint.Y));
}
/// <summary>
/// 使用自己的私钥与对方公钥进行密钥交换（私钥A×公钥B = 私钥B×公钥A）
/// </summary>
/// <param name="privateKey"></param>
/// <param name="publicKey"></param>
/// <returns></returns>
unsafe public static EncryptionKey CreateEncryptionKey(ReadOnlySpan <byte> privateKey, PublicKey publicKey)
{
if (privateKey.Length != 32)
{
throw new InvalidPrivateKeyException("私钥长度必须是32字节");
}
var k = new U256(privateKey);
if (k.IsZero || k >= U256N.N)
{
throw new InvalidPrivateKeyException();
}
var p = (Point)(new JacobianPoint(publicKey.X, publicKey.Y) * k);
return(new EncryptionKey(p.X, p.Y));
}
/// <summary>
/// 根据私钥创建公钥
/// </summary>
/// <param name="privateKey"></param>
/// <returns></returns>
unsafe public static PublicKey CreatePublicKey(ReadOnlySpan <byte> privateKey)
{
if (privateKey.Length != 32)
{
throw new InvalidPrivateKeyException("私钥长度必须是32字节");
}
var k = new U256(privateKey, bigEndian: true);
if (k.IsZero || k >= ModN.N)
{
throw new InvalidPrivateKeyException();
}
var retPoint = ModP.MulG(k);
Clear(&k);
return(new PublicKey(ModP.ToU256(retPoint.X), ModP.ToU256(retPoint.Y)));
}
/// <summary>
/// 使用自己的私钥与对方公钥进行密钥交换（私钥A×公钥B = 私钥B×公钥A）
/// </summary>
/// <param name="privateKey"></param>
/// <param name="publicKey"></param>
/// <returns></returns>
unsafe public static EncryptionKey CreateEncryptionKey(ReadOnlySpan <byte> privateKey, PublicKey publicKey)
{
if (privateKey.Length != 32)
{
throw new InvalidPrivateKeyException("私钥长度必须是32字节");
}
var k = new U256(privateKey, bigEndian: true);
if (k.IsZero || k >= ModN.N)
{
throw new InvalidPrivateKeyException();
}
var p = ModP.Mul(publicKey.ToPoint(), k);
Clear(&k);
return(new EncryptionKey(ModP.ToU256(p.X), ModP.ToU256(p.Y)));
}
/// <summary>
/// 使用私钥对消息进行签名
/// </summary>
/// <param name="privateKey"></param>
/// <param name="message"></param>
/// <returns></returns>
unsafe public static Signature Sign(ReadOnlySpan <byte> privateKey, ReadOnlySpan <byte> message)
{
if (privateKey.Length != 32)
{
throw new InvalidPrivateKeyException("私钥长度必须是32字节");
}
if (message.Length != 32)
{
throw new InvalidMessageException("消息长度必须是32字节");
}
var dA = ModN.U256(privateKey, bigEndian: true);
var msg = ModN.U256(message, bigEndian: true);
var tempPrivKey = CreatePrivateKey();
var tempPubKey = CreatePublicKey(tempPrivKey);
var k = new U256(tempPrivKey, bigEndian: true);
var S = ModN.Div(ModN.Add(msg, ModN.Mul(dA, tempPubKey.x)), k);
tempPrivKey.AsSpan().Clear();
Clear(&dA);
Clear(&k);
return(new Signature(tempPubKey.x, S));
}
