/// <summary>
/// Map a curve name to magic number. Maps the names of the curves that worked pre-Win10
/// to the pre-Win10 magic numbers to support import on pre-Win10 environments
/// that don't have the named curve functionality.
/// </summary>
private static KeyBlobMagicNumber CurveNameToMagicNumber(string name, bool includePrivateParameters)
{
CngAlgorithm alg = CngKey.EcdsaCurveNameToAlgorithm(name);
if (alg == CngAlgorithm.ECDsaP256)
{
return(includePrivateParameters ?
KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P256_MAGIC :
KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P256_MAGIC);
}
if (alg == CngAlgorithm.ECDsaP384)
{
return(includePrivateParameters ?
KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P384_MAGIC :
KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P384_MAGIC);
}
if (alg == CngAlgorithm.ECDsaP521)
{
return(includePrivateParameters ?
KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P521_MAGIC :
KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P521_MAGIC);
}
// all other curves are new in Win10 so use named curves
return(includePrivateParameters ?
KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_GENERIC_MAGIC :
KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_GENERIC_MAGIC);
}
/// <summary>
/// Map a curve name to magic number. Maps the names of the curves that worked pre-Win10
/// to the pre-Win10 magic numbers to support import on pre-Win10 environments
/// that don't have the named curve functionality.
/// </summary>
private static KeyBlobMagicNumber ECDsaCurveNameToMagicNumber(string name, bool includePrivateParameters)
{
switch (CngKey.EcdsaCurveNameToAlgorithm(name).Algorithm)
{
case AlgorithmName.ECDsaP256:
return(includePrivateParameters ?
KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P256_MAGIC :
KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P256_MAGIC);
case AlgorithmName.ECDsaP384:
return(includePrivateParameters ?
KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P384_MAGIC :
KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P384_MAGIC);
case AlgorithmName.ECDsaP521:
return(includePrivateParameters ?
KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_P521_MAGIC :
KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_P521_MAGIC);
default:
// all other curves are new in Win10 so use named curves
return(includePrivateParameters ?
KeyBlobMagicNumber.BCRYPT_ECDSA_PRIVATE_GENERIC_MAGIC :
KeyBlobMagicNumber.BCRYPT_ECDSA_PUBLIC_GENERIC_MAGIC);
}
}
public override void GenerateKey(ECCurve curve)
{
curve.Validate();
_core.DisposeKey();
if (curve.IsNamed)
{
if (string.IsNullOrEmpty(curve.Oid.FriendlyName))
{
throw new PlatformNotSupportedException(SR.Format(SR.Cryptography_InvalidCurveOid, curve.Oid.Value));
}
// Map curve name to algorithm to support pre-Win10 curves
CngAlgorithm alg = CngKey.EcdsaCurveNameToAlgorithm(curve.Oid.FriendlyName);
if (CngKey.IsECNamedCurve(alg.Algorithm))
{
CngKey key = _core.GetOrGenerateKey(curve);
ForceSetKeySize(key.KeySize);
}
else
{
int keySize;
// Get the proper KeySize from algorithm name
if (alg == CngAlgorithm.ECDsaP256)
{
keySize = 256;
}
else if (alg == CngAlgorithm.ECDsaP384)
{
keySize = 384;
}
else if (alg == CngAlgorithm.ECDsaP521)
{
keySize = 521;
}
else
{
Debug.Fail($"Unknown algorithm {alg}");
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
_core.GetOrGenerateKey(keySize, alg);
ForceSetKeySize(keySize);
}
}
else if (curve.IsExplicit)
{
CngKey key = _core.GetOrGenerateKey(curve);
ForceSetKeySize(key.KeySize);
}
else
{
throw new PlatformNotSupportedException(SR.Format(SR.Cryptography_CurveNotSupported, curve.CurveType.ToString()));
}
}
public override void GenerateKey(ECCurve curve)
{
curve.Validate();
if (m_key != null)
{
m_key.Dispose();
m_key = null;
}
CngKey newKey = CngKey.Create(curve, name => CngKey.EcdsaCurveNameToAlgorithm(name));
m_key = newKey;
KeySizeValue = newKey.KeySize;
}
private CngKey GetKey(
#if !NETNATIVE
ECCurve?curve = null
#endif
)
{
CngKey key = null;
CngAlgorithm algorithm = null;
int keySize = 0;
#if !NETNATIVE
if (curve != null)
{
if (curve.Value.IsNamed)
{
// Map curve name to algorithm to support pre-Win10 curves
CngAlgorithm alg = CngKey.EcdsaCurveNameToAlgorithm(curve.Value.Oid.FriendlyName);
if (CngKey.IsECNamedCurve(alg.Algorithm))
{
key = _core.GetOrGenerateKey(curve.Value);
}
else
{
// Get the proper KeySize from algorithm name
if (alg == CngAlgorithm.ECDsaP256)
{
keySize = 256;
}
else if (alg == CngAlgorithm.ECDsaP384)
{
keySize = 384;
}
else if (alg == CngAlgorithm.ECDsaP521)
{
keySize = 521;
}
else
{
Debug.Fail(string.Format("Unknown algorithm {0}", alg.ToString()));
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
key = _core.GetOrGenerateKey(keySize, alg);
}
ForceSetKeySize(key.KeySize);
}
else if (curve.Value.IsExplicit)
{
key = _core.GetOrGenerateKey(curve.Value);
ForceSetKeySize(key.KeySize);
}
else
{
throw new PlatformNotSupportedException(string.Format(SR.Cryptography_CurveNotSupported, curve.Value.CurveType.ToString()));
}
}
else if (_core.IsKeyGeneratedNamedCurve())
{
key = _core.GetOrGenerateKey(null);
}
else
#endif
{
// Map the current key size to a CNG algorithm name
keySize = KeySize;
switch (keySize)
{
case 256: algorithm = CngAlgorithm.ECDsaP256; break;
case 384: algorithm = CngAlgorithm.ECDsaP384; break;
case 521: algorithm = CngAlgorithm.ECDsaP521; break;
default:
Debug.Fail("Should not have invalid key size");
throw new ArgumentException(SR.Cryptography_InvalidKeySize);
}
key = _core.GetOrGenerateKey(keySize, algorithm);
}
return(key);
}
