public override unsafe bool TrySignHash(ReadOnlySpan <byte> source, Span <byte> destination, out int bytesWritten)
{
ReadOnlySpan <byte> hash = source;
#endif
using (SafeNCryptKeyHandle keyHandle = GetDuplicatedKeyHandle())
{
if (!keyHandle.TrySignHash(hash, destination, AsymmetricPaddingMode.None, null, out bytesWritten))
{
bytesWritten = 0;
return(false);
}
}
#if INTERNAL_ASYMMETRIC_IMPLEMENTATIONS
if (signatureFormat == DSASignatureFormat.IeeeP1363FixedFieldConcatenation)
{
return(true);
}
if (signatureFormat != DSASignatureFormat.Rfc3279DerSequence)
{
Debug.Fail($"Missing internal implementation handler for signature format {signatureFormat}");
throw new CryptographicException(
SR.Cryptography_UnknownSignatureFormat,
signatureFormat.ToString());
}
return(AsymmetricAlgorithmHelpers.TryConvertIeee1363ToDer(
destination.Slice(0, bytesWritten),
destination,
out bytesWritten));
#else
return(true);
#endif
}
public override bool VerifyHash(ReadOnlySpan <byte> hash, ReadOnlySpan <byte> signature)
#endif
{
ThrowIfDisposed();
Span <byte> derSignature = stackalloc byte[SignatureStackBufSize];
ReadOnlySpan <byte> toVerify = derSignature;
#if INTERNAL_ASYMMETRIC_IMPLEMENTATIONS
if (signatureFormat == DSASignatureFormat.IeeeP1363FixedFieldConcatenation)
{
#endif
// The signature format for .NET is r.Concat(s). Each of r and s are of length BitsToBytes(KeySize), even
// when they would have leading zeroes. If it's the correct size, then we need to encode it from
// r.Concat(s) to SEQUENCE(INTEGER(r), INTEGER(s)), because that's the format that OpenSSL expects.
int expectedBytes = 2 * AsymmetricAlgorithmHelpers.BitsToBytes(KeySize);
if (signature.Length != expectedBytes)
{
// The input isn't of the right length, so we can't sensibly re-encode it.
return(false);
}
if (AsymmetricAlgorithmHelpers.TryConvertIeee1363ToDer(signature, derSignature, out int derSize))
{
toVerify = derSignature.Slice(0, derSize);
}
else
{
toVerify = AsymmetricAlgorithmHelpers.ConvertIeee1363ToDer(signature);
}
#if INTERNAL_ASYMMETRIC_IMPLEMENTATIONS
}
else if (signatureFormat == DSASignatureFormat.Rfc3279DerSequence)
{
toVerify = signature;
}
else
{
Debug.Fail($"Missing internal implementation handler for signature format {signatureFormat}");
throw new CryptographicException(
SR.Cryptography_UnknownSignatureFormat,
signatureFormat.ToString());
}
#endif
SafeEcKeyHandle key = _key.Value;
int verifyResult = Interop.Crypto.EcDsaVerify(hash, toVerify, key);
return(verifyResult == 1);
}
protected override unsafe bool TryCreateSignatureCore(
ReadOnlySpan <byte> hash,
Span <byte> destination,
DSASignatureFormat signatureFormat,
out int bytesWritten)
{
Span <byte> stackBuf = stackalloc byte[WindowsMaxQSize];
ReadOnlySpan <byte> source = AdjustHashSizeIfNecessary(hash, stackBuf);
using (SafeNCryptKeyHandle keyHandle = GetDuplicatedKeyHandle())
{
if (!CngCommon.TrySignHash(keyHandle, source, destination, AsymmetricPaddingMode.None, null, out bytesWritten))
{
bytesWritten = 0;
return(false);
}
}
if (signatureFormat == DSASignatureFormat.IeeeP1363FixedFieldConcatenation)
{
return(true);
}
if (signatureFormat != DSASignatureFormat.Rfc3279DerSequence)
{
Debug.Fail($"Missing internal implementation handler for signature format {signatureFormat}");
throw new CryptographicException(
SR.Cryptography_UnknownSignatureFormat,
signatureFormat.ToString());
}
return(AsymmetricAlgorithmHelpers.TryConvertIeee1363ToDer(
destination.Slice(0, bytesWritten),
destination,
out bytesWritten));
}
