EcdsaKey
Contains ECDSA (ecdsa-sha2-nistp{256,384,521}) private and public key
using Renci.SshNet.Common;
using Renci.SshNet.Security.Cryptography;
using System;
using System.IO;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
using System.Text;
namespace Renci.SshNet.Security
{
public class EcdsaKey : Key, IDisposable
{
internal enum KeyBlobMagicNumber
{
BCRYPT_ECDSA_PUBLIC_P256_MAGIC = 827540293,
BCRYPT_ECDSA_PRIVATE_P256_MAGIC = 844317509,
BCRYPT_ECDSA_PUBLIC_P384_MAGIC = 861094725,
BCRYPT_ECDSA_PRIVATE_P384_MAGIC = 877871941,
BCRYPT_ECDSA_PUBLIC_P521_MAGIC = 894649157,
BCRYPT_ECDSA_PRIVATE_P521_MAGIC = 911426373,
BCRYPT_ECDH_PUBLIC_P256_MAGIC = 827016005,
BCRYPT_ECDH_PRIVATE_P256_MAGIC = 843793221,
BCRYPT_ECDH_PUBLIC_P384_MAGIC = 860570437,
BCRYPT_ECDH_PRIVATE_P384_MAGIC = 877347653,
BCRYPT_ECDH_PUBLIC_P521_MAGIC = 894124869,
BCRYPT_ECDH_PRIVATE_P521_MAGIC = 910902085,
BCRYPT_ECDH_PUBLIC_GENERIC_MAGIC = 1347109701,
BCRYPT_ECDH_PRIVATE_GENERIC_MAGIC = 1447772997
}
internal struct BCRYPT_ECCKEY_BLOB
{
internal KeyBlobMagicNumber Magic;
internal int cbKey;
}
internal const string ECDSA_P256_OID_VALUE = "1.2.840.10045.3.1.7";
internal const string ECDSA_P384_OID_VALUE = "1.3.132.0.34";
internal const string ECDSA_P521_OID_VALUE = "1.3.132.0.35";
private CngKey key;
private EcdsaDigitalSignature _digitalSignature;
private bool _isDisposed;
public CngAlgorithm HashAlgorithm {
get {
switch (Ecdsa.KeySize) {
case 256:
return CngAlgorithm.Sha256;
case 384:
return CngAlgorithm.Sha384;
case 521:
return CngAlgorithm.Sha512;
default:
throw new SshException("Unknown KeySize: " + Ecdsa.KeySize.ToString());
}
}
}
public override int KeyLength => Ecdsa.KeySize;
protected override DigitalSignature DigitalSignature {
get {
if (_digitalSignature == null)
_digitalSignature = new EcdsaDigitalSignature(this);
return _digitalSignature;
}
}
public override BigInteger[] Public {
get {
KeyBlobMagicNumber keyBlobMagicNumber;
byte[] array = default(byte[]);
byte[] array2 = default(byte[]);
using (BinaryReader binaryReader = new BinaryReader(new MemoryStream(key.Export(CngKeyBlobFormat.EccPublicBlob)))) {
keyBlobMagicNumber = (KeyBlobMagicNumber)binaryReader.ReadInt32();
int count = binaryReader.ReadInt32();
array = binaryReader.ReadBytes(count);
array2 = binaryReader.ReadBytes(count);
}
byte[] bytes;
switch (keyBlobMagicNumber) {
case KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P256_MAGIC:
bytes = Encoding.ASCII.GetBytes("nistp256");
break;
case KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P384_MAGIC:
bytes = Encoding.ASCII.GetBytes("nistp384");
break;
case KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P521_MAGIC:
bytes = Encoding.ASCII.GetBytes("nistp521");
break;
default:
throw new SshException("Unexpected Curve Magic: " + keyBlobMagicNumber.ToString());
}
byte[] array3 = new byte[1 + array.Length + array2.Length];
Buffer.SetByte(array3, 0, 4);
Buffer.BlockCopy(array, 0, array3, 1, array.Length);
Buffer.BlockCopy(array2, 0, array3, array.Length + 1, array2.Length);
return new BigInteger[2] {
new BigInteger(bytes.Reverse()),
new BigInteger(array3.Reverse())
};
}
set {
string string = Encoding.ASCII.GetString(value[0].ToByteArray().Reverse());
string curveOid = GetCurveOid(string);
byte[] publickey = value[1].ToByteArray().Reverse();
Import(curveOid, publickey, null);
}
}
public ECDsa Ecdsa { get; set; }
public override string ToString()
{
return $"""{KeyLength}";
}
public EcdsaKey()
{
}
public EcdsaKey(string curve, byte[] publickey, byte[] privatekey)
{
Import(GetCurveOid(curve), publickey, privatekey);
}
public EcdsaKey(byte[] data)
{
DerData derData = new DerData(data, false);
derData.ReadBigInteger();
byte[] privatekey = derData.ReadOctetString().TrimLeadingZeros();
byte b = derData.ReadByte();
if ((b & 224) != 160)
throw new SshException($"""{b:""}");
int num = b & 31;
if (num != 0)
throw new SshException($"""{num}");
byte[] oid = new DerData(derData.ReadBytes(derData.ReadLength()), true).ReadObject();
b = derData.ReadByte();
if ((b & 224) != 160)
throw new SshException($"""{b:""}");
num = (b & 31);
if (num != 1)
throw new SshException($"""{num}");
byte[] publickey = new DerData(derData.ReadBytes(derData.ReadLength()), true).ReadBitString().TrimLeadingZeros();
Import(OidByteArrayToString(oid), publickey, privatekey);
}
private void Import(string curve_oid, byte[] publickey, byte[] privatekey)
{
KeyBlobMagicNumber keyBlobMagicNumber = KeyBlobMagicNumber.BCRYPT_ECDH_PRIVATE_GENERIC_MAGIC;
switch (GetCurveName(curve_oid)) {
case "nistp256":
keyBlobMagicNumber = ((privatekey == null) ? KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P256_MAGIC : KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P256_MAGIC);
break;
case "nistp384":
keyBlobMagicNumber = ((privatekey == null) ? KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P384_MAGIC : KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P384_MAGIC);
break;
case "nistp521":
keyBlobMagicNumber = ((privatekey == null) ? KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P521_MAGIC : KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P521_MAGIC);
break;
default:
throw new SshException("Unknown: " + curve_oid);
}
int num = (publickey.Length - 1) / 2;
byte[] array = new byte[num];
Buffer.BlockCopy(publickey, 1, array, 0, array.Length);
byte[] array2 = new byte[num];
Buffer.BlockCopy(publickey, num + 1, array2, 0, array2.Length);
if (privatekey != null)
privatekey = privatekey.Pad(num);
int num2 = Marshal.SizeOf(typeof(BCRYPT_ECCKEY_BLOB)) + array.Length + array2.Length;
if (privatekey != null)
num2 += privatekey.Length;
byte[] array3 = new byte[num2];
using (BinaryWriter binaryWriter = new BinaryWriter(new MemoryStream(array3))) {
binaryWriter.Write((int)keyBlobMagicNumber);
binaryWriter.Write(num);
binaryWriter.Write(array);
binaryWriter.Write(array2);
if (privatekey != null)
binaryWriter.Write(privatekey);
}
key = CngKey.Import(array3, (privatekey == null) ? CngKeyBlobFormat.EccPublicBlob : CngKeyBlobFormat.EccPrivateBlob);
Ecdsa = new ECDsaCng(key);
}
private string GetCurveOid(string curve_s)
{
switch (curve_s.ToLower()) {
case "nistp256":
return "1.2.840.10045.3.1.7";
case "nistp384":
return "1.3.132.0.34";
case "nistp521":
return "1.3.132.0.35";
default:
throw new SshException("Unexpected Curve Name: " + curve_s);
}
}
private string GetCurveName(string oid)
{
if (oid != null) {
if (oid == "1.2.840.10045.3.1.7")
return "nistp256";
if (oid == "1.3.132.0.34")
return "nistp384";
if (oid == "1.3.132.0.35")
return "nistp521";
}
throw new SshException("Unexpected OID: " + oid);
}
private string OidByteArrayToString(byte[] oid)
{
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i < oid.Length; i++) {
if (i == 0) {
int num = (int)oid[0] % 40;
int num2 = (oid[0] - num) / 40;
stringBuilder.AppendFormat("{0}.{1}", num2, num);
} else if (oid[i] < 128) {
stringBuilder.AppendFormat(".{0}", oid[i]);
} else {
stringBuilder.AppendFormat(".{0}", (oid[i] - 128) * 128 + oid[i + 1]);
i++;
}
}
return stringBuilder.ToString();
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (!_isDisposed && disposing)
_isDisposed = true;
}
~EcdsaKey()
{
Dispose(false);
}
}
}