private static GostKeyExchangeParameters DecodePublicBlob(byte[] encodedPublicBlob, GostAlgorithmType algorithm)
{
if (encodedPublicBlob == null)
{
throw ExceptionUtility.ArgumentNull("encodedPublicBlob");
}
int size;
switch (algorithm)
{
case GostAlgorithmType.Gost2001:
size = 512;
break;
case GostAlgorithmType.Gost2012_256:
size = 512;
break;
case GostAlgorithmType.Gost2012_512:
size = 1024;
break;
default:
throw new CryptographicException(Resources.AlgorithmNotAvailable);
}
if (encodedPublicBlob.Length < 16 + size / 8)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
var gostKeyMask = BitConverter.ToUInt32(encodedPublicBlob, 8);
if (gostKeyMask != Constants.GR3410_1_MAGIC)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
var gostKeySize = BitConverter.ToUInt32(encodedPublicBlob, 12);
if (gostKeySize != size)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
var publicKeyParameters = new GostKeyExchangeParameters();
var encodeKeyParameters = new byte[(encodedPublicBlob.Length - 16) - size / 8];
Array.Copy(encodedPublicBlob, 16, encodeKeyParameters, 0, (encodedPublicBlob.Length - 16) - size / 8);
publicKeyParameters.DecodeParameters(encodeKeyParameters);
var publicKey = new byte[64];
Array.Copy(encodedPublicBlob, encodedPublicBlob.Length - size / 8, publicKey, 0, size / 8);
publicKeyParameters.PublicKey = publicKey;
return(publicKeyParameters);
}
public static AsymmetricAlgorithm GetPublicKeyAlgorithm(this X509Certificate2 certificate)
{
if (certificate == null)
{
throw ExceptionUtility.ArgumentNull("certificate");
}
var cspObject = new GostKeyExchangeParameters();
cspObject.DecodeParameters(certificate.PublicKey.EncodedParameters.RawData);
cspObject.DecodePublicKey(certificate.PublicKey.EncodedKeyValue.RawData);
var cspBlobData = CryptoApiHelper.EncodePublicBlob(cspObject);
var publicKey = new Gost3410AsymmetricAlgorithm();
publicKey.ImportCspBlob(cspBlobData);
return(publicKey);
}
private static GostKeyExchangeParameters DecodePublicBlob(byte[] encodedPublicBlob)
{
if (encodedPublicBlob == null)
{
throw ExceptionUtility.ArgumentNull("encodedPublicBlob");
}
if (encodedPublicBlob.Length < 80)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
var gostKeyMask = BitConverter.ToUInt32(encodedPublicBlob, 8);
if (gostKeyMask != Constants.GR3410_1_MAGIC)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
var gostKeySize = BitConverter.ToUInt32(encodedPublicBlob, 12);
if (gostKeySize != 512)
{
throw ExceptionUtility.CryptographicException(Constants.NTE_BAD_DATA);
}
var publicKeyParameters = new GostKeyExchangeParameters();
var encodeKeyParameters = new byte[(encodedPublicBlob.Length - 16) - 64];
Array.Copy(encodedPublicBlob, 16, encodeKeyParameters, 0, (encodedPublicBlob.Length - 16) - 64);
publicKeyParameters.DecodeParameters(encodeKeyParameters);
var publicKey = new byte[64];
Array.Copy(encodedPublicBlob, encodedPublicBlob.Length - 64, publicKey, 0, 64);
publicKeyParameters.PublicKey = publicKey;
return(publicKeyParameters);
}
/// <summary>
/// Разбор BLOB открытого ключа ГОСТ 34.10.
/// </summary>
///
/// <param name="obj">Gost3410CspObject</param>
/// <param name="data">BLOB</param>
/// <param name="alg">Тип алгоритма</param>
///
/// <argnull name="obj" />
/// <exception cref="CryptographicException">Если
/// <paramref name="obj"/> не объект типа
/// <see cref="Gost3410CspObject"/></exception>
///
/// <intdoc><para>Аналог в MS отсутствует, часть реализации
/// присутствует в ImportKey. </para></intdoc>
///
/// <unmanagedperm action="LinkDemand" />
internal static void DecodePublicBlob(Object obj, byte[] data, CspAlgorithmType alg)
{
int keySize;
switch (alg)
{
case CspAlgorithmType.PROV_GOST_2001_DH:
keySize = GostConstants.GOST_3410EL_SIZE;
break;
case CspAlgorithmType.PROV_GOST_2012_256:
keySize = GostConstants.GOST3410_2012_256KEY_SIZE;
break;
case CspAlgorithmType.PROV_GOST_2012_512:
keySize = GostConstants.GOST3410_2012_512KEY_SIZE;
break;
default:
throw new CryptographicException(SR.Cryptography_CSP_WrongKeySpec);
}
if (obj == null)
{
throw new ArgumentNullException("obj");
}
Gost3410CspObject cspObject = obj as Gost3410CspObject;
if (cspObject == null)
{
throw new CryptographicException(GostConstants.NTE_BAD_ALGID);
}
if (data.Length < 16 + keySize / 8)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
// CRYPT_PUBKEYPARAM -> 8 { Magic, BitLen )
uint magic = BitConverter.ToUInt32(data, 8);
uint bitlen = BitConverter.ToUInt32(data, 12);
if (magic != GostConstants.GR3410_1_MAGIC)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
if (bitlen != keySize)
{
throw new CryptographicException(GostConstants.NTE_BAD_DATA);
}
byte[] tmp = new byte[data.Length - 16 - keySize / 8];
Array.Copy(data, 16, tmp, 0, data.Length - 16 - keySize / 8);
var publicKeyParameters = new GostKeyExchangeParameters();
var encodeKeyParameters = new byte[(data.Length - 16) - keySize / 8];
Array.Copy(data, 16, encodeKeyParameters, 0, (data.Length - 16) - keySize / 8);
publicKeyParameters.DecodeParameters(encodeKeyParameters);
var publicKey = new byte[keySize / 8];
Array.Copy(data, data.Length - keySize / 8, publicKey, 0, keySize / 8);
publicKeyParameters.PublicKey = publicKey;
cspObject._publicKey = publicKeyParameters.PublicKey;
cspObject._publicKeyParamSet = publicKeyParameters.PublicKeyParamSet;
cspObject._digestParamSet = publicKeyParameters.DigestParamSet;
}
public AsymmetricAlgorithm DecodePublicKey(Oid oid, byte[] encodedKeyValue, byte[] encodedParameters, ICertificatePal certificatePal)
{
if (oid.Value == Oids.EcPublicKey && certificatePal != null)
{
return(DecodeECDsaPublicKey((CertificatePal)certificatePal));
}
int algId = Interop.Crypt32.FindOidInfo(CryptOidInfoKeyType.CRYPT_OID_INFO_OID_KEY, oid.Value, OidGroup.PublicKeyAlgorithm, fallBackToAllGroups: true).AlgId;
switch (algId)
{
case AlgId.CALG_RSA_KEYX:
case AlgId.CALG_RSA_SIGN:
{
byte[] keyBlob = DecodeKeyBlob(CryptDecodeObjectStructType.CNG_RSA_PUBLIC_KEY_BLOB, encodedKeyValue);
CngKey cngKey = CngKey.Import(keyBlob, CngKeyBlobFormat.GenericPublicBlob);
return(new RSACng(cngKey));
}
//begin: gost
case AlgId.CALG_GOST3410:
{
var cspObject = new GostKeyExchangeParameters();
cspObject.DecodeParameters(encodedParameters);
cspObject.DecodePublicKey(encodedKeyValue, algId);
var cspBlobData = GostKeyExchangeParameters.EncodePublicBlob(cspObject, algId);
Gost3410CryptoServiceProvider gost_sp = new Gost3410CryptoServiceProvider();
gost_sp.ImportCspBlob(cspBlobData);
return(gost_sp);
}
case AlgId.CALG_GOST3410_2012_256:
{
var cspObject = new GostKeyExchangeParameters();
cspObject.DecodeParameters(encodedParameters);
cspObject.DecodePublicKey(encodedKeyValue, algId);
var cspBlobData = GostKeyExchangeParameters.EncodePublicBlob(cspObject, algId);
Gost3410_2012_256CryptoServiceProvider gost_sp = new Gost3410_2012_256CryptoServiceProvider();
gost_sp.ImportCspBlob(cspBlobData);
return(gost_sp);
}
case AlgId.CALG_GOST3410_2012_512:
{
var cspObject = new GostKeyExchangeParameters();
cspObject.DecodeParameters(encodedParameters);
cspObject.DecodePublicKey(encodedKeyValue, algId);
var cspBlobData = GostKeyExchangeParameters.EncodePublicBlob(cspObject, algId);
Gost3410_2012_512CryptoServiceProvider gost_sp = new Gost3410_2012_512CryptoServiceProvider();
gost_sp.ImportCspBlob(cspBlobData);
return(gost_sp);
}
//end: gost
case AlgId.CALG_DSS_SIGN:
{
byte[] keyBlob = ConstructDSSPublicKeyCspBlob(encodedKeyValue, encodedParameters);
DSACryptoServiceProvider dsa = new DSACryptoServiceProvider();
dsa.ImportCspBlob(keyBlob);
return(dsa);
}
default:
throw new NotSupportedException(SR.NotSupported_KeyAlgorithm);
}
}
