/// <summary>
/// Computes the signature of a hash that was produced by the hash algorithm specified by "hashAlgorithm."
/// </summary>
public override byte[] SignHash(byte[] hash)
{
if (hash == null)
{
throw new ArgumentNullException("hash");
}
int estimatedSize;
switch (KeySize)
{
case 256: estimatedSize = 64; break;
case 384: estimatedSize = 96; break;
case 521: estimatedSize = 132; break;
default:
// If we got here, the range of legal key sizes for ECDsaCng was expanded and someone didn't update this switch.
// Since it isn't a fatal error to miscalculate the estimatedSize, don't throw an exception. Just truck along.
estimatedSize = KeySize / 4;
break;
}
unsafe
{
byte[] signature = CngAsymmetricAlgorithmCore.SignHash(Key, hash, AsymmetricPaddingMode.None, null, estimatedSize);
return(signature);
}
}
/// <summary>
/// Creates a new ECDsaCng object that will use the specified key. The key's
/// <see cref="CngKey.AlgorithmGroup" /> must be ECDsa. This constructor
/// creates a copy of the key. Hence, the caller can safely dispose of the
/// passed in key and continue using the ECDsaCng object.
/// </summary>
/// <param name="key">Key to use for ECDsa operations</param>
/// <exception cref="ArgumentException">if <paramref name="key" /> is not an ECDsa key</exception>
/// <exception cref="ArgumentNullException">if <paramref name="key" /> is null.</exception>
public ECDsaCng(CngKey key)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (key.AlgorithmGroup != CngAlgorithmGroup.ECDsa)
{
throw new ArgumentException(SR.Cryptography_ArgECDsaRequiresECDsaKey, "key");
}
Key = CngAsymmetricAlgorithmCore.Duplicate(key);
}
/// <summary>
/// Creates a new RSACng object that will use the specified key. The key's
/// <see cref="CngKey.AlgorithmGroup" /> must be Rsa. This constructor
/// creates a copy of the key. Hence, the caller can safely dispose of the
/// passed in key and continue using the RSACng object.
/// </summary>
/// <param name="key">Key to use for RSA operations</param>
/// <exception cref="ArgumentException">if <paramref name="key" /> is not an RSA key</exception>
/// <exception cref="ArgumentNullException">if <paramref name="key" /> is null.</exception>
public RSACng(CngKey key)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
if (key.AlgorithmGroup != CngAlgorithmGroup.Rsa)
{
throw new ArgumentException(SR.Cryptography_ArgRSAaRequiresRSAKey, "key");
}
_legalKeySizesValue = s_legalKeySizes;
Key = CngAsymmetricAlgorithmCore.Duplicate(key);
}
/// <summary>
/// Verifies that alleged signature of a hash is, in fact, a valid signature of that hash.
/// </summary>
public override bool VerifyHash(byte[] hash, byte[] signature)
{
if (hash == null)
{
throw new ArgumentNullException("hash");
}
if (signature == null)
{
throw new ArgumentNullException("signature");
}
unsafe
{
bool verified = CngAsymmetricAlgorithmCore.VerifyHash(Key, hash, signature, AsymmetricPaddingMode.None, null);
return(verified);
}
}
/// <summary>
/// Computes the signature of a hash that was produced by the hash algorithm specified by "hashAlgorithm."
/// </summary>
public override byte[] SignHash(byte[] hash, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
{
if (hash == null)
{
throw new ArgumentNullException("hash");
}
unsafe
{
byte[] signature = null;
SignOrVerify(padding, hashAlgorithm, hash,
delegate(AsymmetricPaddingMode paddingMode, void *pPaddingInfo)
{
int estimatedSize = KeySize / 8;
signature = CngAsymmetricAlgorithmCore.SignHash(Key, hash, paddingMode, pPaddingInfo, estimatedSize);
}
);
return(signature);
}
}
/// <summary>
/// Verifies that alleged signature of a hash is, in fact, a valid signature of that hash.
/// </summary>
public override bool VerifyHash(byte[] hash, byte[] signature, HashAlgorithmName hashAlgorithm, RSASignaturePadding padding)
{
if (hash == null)
{
throw new ArgumentNullException("hash");
}
if (signature == null)
{
throw new ArgumentNullException("signature");
}
unsafe
{
bool verified = false;
SignOrVerify(padding, hashAlgorithm, hash,
delegate(AsymmetricPaddingMode paddingMode, void *pPaddingInfo)
{
verified = CngAsymmetricAlgorithmCore.VerifyHash(Key, hash, signature, paddingMode, pPaddingInfo);
}
);
return(verified);
}
}
protected override byte[] HashData(Stream data, HashAlgorithmName hashAlgorithm)
{
return(CngAsymmetricAlgorithmCore.HashData(data, hashAlgorithm));
}
protected override byte[] HashData(byte[] data, int offset, int count, HashAlgorithmName hashAlgorithm)
{
return(CngAsymmetricAlgorithmCore.HashData(data, offset, count, hashAlgorithm));
}
