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Merged
vcsjones merged 3 commits into from
May 9, 2026
Merged

Implement X25519DiffieHellmanCng #127924

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Implement X25519DiffieHellmanCng
vcsjones May 7, 2026
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vcsjones May 7, 2026
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vcsjones May 8, 2026
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3 changes: 3 additions & 0 deletions src/libraries/Common/src/Interop/Windows/NCrypt/Interop.Keys.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,9 @@ internal static partial class NCrypt
[LibraryImport(Interop.Libraries.NCrypt, StringMarshalling = StringMarshalling.Utf16)]
internal static partial ErrorCode NCryptExportKey(SafeNCryptKeyHandle hKey, IntPtr hExportKey, string pszBlobType, IntPtr pParameterList, ref byte pbOutput, int cbOutput, out int pcbResult, int dwFlags);

[LibraryImport(Interop.Libraries.NCrypt, StringMarshalling = StringMarshalling.Utf16)]
internal static partial ErrorCode NCryptExportKey(SafeNCryptKeyHandle hKey, IntPtr hExportKey, string pszBlobType, IntPtr pParameterList, Span<byte> pbOutput, int cbOutput, out int pcbResult, int dwFlags);

[LibraryImport(Interop.Libraries.NCrypt, StringMarshalling = StringMarshalling.Utf16)]
internal static partial ErrorCode NCryptExportKey(SafeNCryptKeyHandle hKey, IntPtr hExportKey, string pszBlobType, ref NCryptBufferDesc pParameterList, ref byte pbOutput, int cbOutput, out int pcbResult, int dwFlags);

Expand Down
40 changes: 40 additions & 0 deletions src/libraries/Common/src/Interop/Windows/NCrypt/Interop.NCryptDeriveKeyMaterial.cs
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Expand Up @@ -25,6 +25,16 @@ private static partial ErrorCode NCryptDeriveKey(
out int pcbResult,
SecretAgreementFlags dwFlags);

[LibraryImport(Interop.Libraries.NCrypt, StringMarshalling = StringMarshalling.Utf16)]
private static partial ErrorCode NCryptDeriveKey(
SafeNCryptSecretHandle hSharedSecret,
string pwszKDF,
IntPtr pParameterList,
Span<byte> pbDerivedKey,
int cbDerivedKey,
out int pcbResult,
SecretAgreementFlags dwFlags);

/// <summary>
/// Derive key material from a hash or HMAC KDF
/// </summary>
Expand Down Expand Up @@ -257,5 +267,35 @@ internal static byte[] DeriveKeyMaterialTruncate(
Array.Reverse(result);
return result;
}

internal static bool TryDeriveKeyMaterialTruncate(
SafeNCryptSecretHandle secretAgreement,
SecretAgreementFlags flags,
Span<byte> destination,
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out int bytesWritten)
{
ErrorCode error = NCryptDeriveKey(
secretAgreement,
BCryptNative.KeyDerivationFunction.Raw,
IntPtr.Zero,
destination,
destination.Length,
out int localWritten,
flags);

switch (error)
{
case ErrorCode.ERROR_SUCCESS:
destination.Slice(0, localWritten).Reverse();
bytesWritten = localWritten;
return true;
case ErrorCode c when c.IsBufferTooSmall():
destination.Clear();
bytesWritten = 0;
return false;
default:
throw error.ToCryptographicException();
}
}
}
}
5 changes: 3 additions & 2 deletions src/libraries/Common/src/System/Security/Cryptography/ECCng.ImportExport.NamedCurve.cs
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Expand Up @@ -145,7 +145,8 @@ internal static SafeNCryptKeyHandle ImportKeyBlob(
string blobType,
ReadOnlySpan<byte> keyBlob,
string curveName,
SafeNCryptProviderHandle provider)
SafeNCryptProviderHandle provider,
int flags = 0)
{
ErrorCode errorCode;
SafeNCryptKeyHandle keyHandle;
Expand Down Expand Up @@ -173,7 +174,7 @@ internal static SafeNCryptKeyHandle ImportKeyBlob(
out keyHandle,
ref MemoryMarshal.GetReference(keyBlob),
keyBlob.Length,
0);
flags);
}
}

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71 changes: 71 additions & 0 deletions src/libraries/Common/src/System/Security/Cryptography/KeyFormatHelper.Encrypted.cs
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Expand Up @@ -32,6 +32,29 @@ internal static void ReadEncryptedPkcs8<TRet>(
out ret);
}

internal static void ReadEncryptedPkcs8<TRet, TState>(
string[] validOids,
ReadOnlySpan<byte> source,
ReadOnlySpan<char> password,
TState state,
KeyReader<TRet, TState> keyReader,
out int bytesRead,
out TRet ret)
#if NET
where TState : allows ref struct
#endif
{
ReadEncryptedPkcs8(
validOids,
source,
password,
ReadOnlySpan<byte>.Empty,
state,
keyReader,
out bytesRead,
out ret);
}

internal static void ReadEncryptedPkcs8<TRet>(
string[] validOids,
ReadOnlySpan<byte> source,
Expand All @@ -50,6 +73,29 @@ internal static void ReadEncryptedPkcs8<TRet>(
out ret);
}

internal static void ReadEncryptedPkcs8<TRet, TState>(
string[] validOids,
ReadOnlySpan<byte> source,
ReadOnlySpan<byte> passwordBytes,
TState state,
KeyReader<TRet, TState> keyReader,
out int bytesRead,
out TRet ret)
#if NET
where TState : allows ref struct
#endif
{
ReadEncryptedPkcs8(
validOids,
source,
ReadOnlySpan<char>.Empty,
passwordBytes,
state,
keyReader,
out bytesRead,
out ret);
}

private static void ReadEncryptedPkcs8<TRet>(
string[] validOids,
ReadOnlySpan<byte> source,
Expand All @@ -58,6 +104,30 @@ private static void ReadEncryptedPkcs8<TRet>(
KeyReader<TRet> keyReader,
out int bytesRead,
out TRet ret)
{
ReadEncryptedPkcs8<TRet, KeyReader<TRet>>(
validOids,
source,
password,
passwordBytes,
keyReader,
static (key, kr, in algId, out ret) => kr(key, algId, out ret),
out bytesRead,
out ret);
}

private static void ReadEncryptedPkcs8<TRet, TState>(
string[] validOids,
ReadOnlySpan<byte> source,
ReadOnlySpan<char> password,
ReadOnlySpan<byte> passwordBytes,
TState state,
KeyReader<TRet, TState> keyReader,
out int bytesRead,
out TRet ret)
#if NET
where TState : allows ref struct
#endif
{
int read;
ValueEncryptedPrivateKeyInfoAsn epki;
Expand Down Expand Up @@ -92,6 +162,7 @@ private static void ReadEncryptedPkcs8<TRet>(
ReadPkcs8(
validOids,
decryptedMemory.Span,
state,
keyReader,
out int innerRead,
out ret);
Expand Down
29 changes: 28 additions & 1 deletion src/libraries/Common/src/System/Security/Cryptography/KeyFormatHelper.cs
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Expand Up @@ -13,6 +13,13 @@ internal static partial class KeyFormatHelper
{
internal delegate void KeyReader<TRet>(ReadOnlySpan<byte> key, in ValueAlgorithmIdentifierAsn algId, out TRet ret);

internal delegate void KeyReader<TRet, TState>(ReadOnlySpan<byte> key, TState state, in ValueAlgorithmIdentifierAsn algId, out TRet ret)
#if NET
where TState : allows ref struct;
#else
;
#endif

internal static void ReadSubjectPublicKeyInfo<TRet>(
string[] validOids,
ReadOnlySpan<byte> source,
Expand Down Expand Up @@ -78,6 +85,26 @@ internal static void ReadPkcs8<TRet>(
KeyReader<TRet> keyReader,
out int bytesRead,
out TRet ret)
{
ReadPkcs8<TRet, KeyReader<TRet>>(
validOids,
source,
keyReader,
static (key, kr, in algId, out ret) => kr(key, algId, out ret),
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out bytesRead,
out ret);
}

internal static void ReadPkcs8<TRet, TState>(
string[] validOids,
ReadOnlySpan<byte> source,
TState state,
KeyReader<TRet, TState> keyReader,
out int bytesRead,
out TRet ret)
#if NET
where TState : allows ref struct
#endif
{
try
{
Expand All @@ -91,7 +118,7 @@ internal static void ReadPkcs8<TRet>(
}

// Fails if there are unconsumed bytes.
keyReader(privateKeyInfo.PrivateKey, privateKeyInfo.PrivateKeyAlgorithm, out ret);
keyReader(privateKeyInfo.PrivateKey, state, privateKeyInfo.PrivateKeyAlgorithm, out ret);
bytesRead = read;
}
catch (AsnContentException e)
Expand Down
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