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Pulsar .NET 9.0 Windows Release / build (push) Waiting to run
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initial commit
2026-08-27 10:57:58 -06:00

342 lines
14 KiB
C#

#if NETFRAMEWORK
using System;
using System.Runtime.InteropServices;
using System.Security.Cryptography;
using System.Text;
using Microsoft.Win32.SafeHandles;
namespace Pulsar.Common.Cryptography
{
internal static class AesGcmCng
{
private const uint ERROR_SUCCESS = 0x00000000;
private const uint STATUS_AUTH_TAG_MISMATCH = 0xC000A002;
private const string BCRYPT_AES_ALGORITHM = "AES";
private const string MS_PRIMITIVE_PROVIDER = "Microsoft Primitive Provider";
private const string BCRYPT_CHAINING_MODE = "ChainingMode";
private const string BCRYPT_CHAIN_MODE_GCM = "ChainingModeGCM";
private const string BCRYPT_OBJECT_LENGTH = "ObjectLength";
private const string BCRYPT_KEY_DATA_BLOB = "KeyDataBlob";
private static readonly byte[] KeyBlobMagic = BitConverter.GetBytes(0x4d42444b); // "KDBM"
internal static void Encrypt(byte[] key, byte[] nonce, byte[] plaintext, byte[] ciphertext, byte[] tag)
{
if (key == null) throw new ArgumentNullException(nameof(key));
if (nonce == null) throw new ArgumentNullException(nameof(nonce));
if (plaintext == null) throw new ArgumentNullException(nameof(plaintext));
if (ciphertext == null) throw new ArgumentNullException(nameof(ciphertext));
if (tag == null) throw new ArgumentNullException(nameof(tag));
if (ciphertext.Length != plaintext.Length)
{
throw new CryptographicException("Ciphertext buffer length must match plaintext length.");
}
using (SafeAlgorithmHandle algorithm = OpenAlgorithm())
using (SafeKeyHandle keyHandle = ImportKey(algorithm, key))
{
byte[] output = new byte[ciphertext.Length];
byte[] tagBuffer = new byte[tag.Length];
AuthInfo authInfo = new AuthInfo(nonce, null, tagBuffer);
try
{
byte[] ivBuffer = (byte[])nonce.Clone();
int result = 0;
uint status = BCryptEncrypt(keyHandle.DangerousGetHandle(), plaintext, plaintext.Length, ref authInfo.Info, ivBuffer, ivBuffer.Length, output, output.Length, ref result, 0);
if (status != ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("BCryptEncrypt failed with status code 0x{0:X8}.", status));
}
if (result != ciphertext.Length)
{
throw new CryptographicException("Ciphertext length mismatch during encryption.");
}
Buffer.BlockCopy(output, 0, ciphertext, 0, result);
authInfo.CopyTag(tag);
}
finally
{
authInfo.Dispose();
}
}
}
internal static void Decrypt(byte[] key, byte[] nonce, byte[] ciphertext, byte[] tag, byte[] plaintext)
{
if (key == null) throw new ArgumentNullException(nameof(key));
if (nonce == null) throw new ArgumentNullException(nameof(nonce));
if (ciphertext == null) throw new ArgumentNullException(nameof(ciphertext));
if (tag == null) throw new ArgumentNullException(nameof(tag));
if (plaintext == null) throw new ArgumentNullException(nameof(plaintext));
if (ciphertext.Length != plaintext.Length)
{
throw new CryptographicException("Plaintext buffer length must match ciphertext length.");
}
using (SafeAlgorithmHandle algorithm = OpenAlgorithm())
using (SafeKeyHandle keyHandle = ImportKey(algorithm, key))
{
byte[] output = new byte[plaintext.Length];
AuthInfo authInfo = new AuthInfo(nonce, null, tag);
try
{
byte[] ivBuffer = (byte[])nonce.Clone();
int result = 0;
uint status = BCryptDecrypt(keyHandle.DangerousGetHandle(), ciphertext, ciphertext.Length, ref authInfo.Info, ivBuffer, ivBuffer.Length, output, output.Length, ref result, 0);
if (status == STATUS_AUTH_TAG_MISMATCH)
{
throw new CryptographicException("Authentication tag mismatch during decryption.");
}
if (status != ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("BCryptDecrypt failed with status code 0x{0:X8}.", status));
}
if (result != plaintext.Length)
{
throw new CryptographicException("Plaintext length mismatch during decryption.");
}
Buffer.BlockCopy(output, 0, plaintext, 0, result);
}
finally
{
authInfo.Dispose();
}
}
}
private static SafeAlgorithmHandle OpenAlgorithm()
{
IntPtr rawHandle;
uint status = BCryptOpenAlgorithmProvider(out rawHandle, BCRYPT_AES_ALGORITHM, MS_PRIMITIVE_PROVIDER, 0);
if (status != ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("BCryptOpenAlgorithmProvider failed with status code 0x{0:X8}.", status));
}
SafeAlgorithmHandle handle = new SafeAlgorithmHandle(rawHandle);
try
{
byte[] chainMode = Encoding.Unicode.GetBytes(BCRYPT_CHAIN_MODE_GCM);
status = BCryptSetAlgorithmProperty(handle.DangerousGetHandle(), BCRYPT_CHAINING_MODE, chainMode, chainMode.Length, 0);
if (status != ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("BCryptSetAlgorithmProperty failed with status code 0x{0:X8}.", status));
}
return handle;
}
catch
{
handle.Dispose();
throw;
}
}
private static SafeKeyHandle ImportKey(SafeAlgorithmHandle algorithm, byte[] key)
{
byte[] objectLength = GetAlgorithmProperty(algorithm.DangerousGetHandle(), BCRYPT_OBJECT_LENGTH);
int keyObjectSize = BitConverter.ToInt32(objectLength, 0);
IntPtr keyObject = Marshal.AllocHGlobal(keyObjectSize);
try
{
byte[] blob = BuildKeyBlob(key);
IntPtr rawKey;
uint status = BCryptImportKey(algorithm.DangerousGetHandle(), IntPtr.Zero, BCRYPT_KEY_DATA_BLOB, out rawKey, keyObject, keyObjectSize, blob, blob.Length, 0);
if (status != ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("BCryptImportKey failed with status code 0x{0:X8}.", status));
}
return new SafeKeyHandle(rawKey, keyObject);
}
catch
{
Marshal.FreeHGlobal(keyObject);
throw;
}
}
private static byte[] GetAlgorithmProperty(IntPtr handle, string property)
{
int size = 0;
uint status = BCryptGetProperty(handle, property, null, 0, ref size, 0);
if (status != ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("BCryptGetProperty (query size) failed with status code 0x{0:X8}.", status));
}
byte[] buffer = new byte[size];
status = BCryptGetProperty(handle, property, buffer, buffer.Length, ref size, 0);
if (status != ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("BCryptGetProperty failed with status code 0x{0:X8}.", status));
}
return buffer;
}
private static byte[] BuildKeyBlob(byte[] key)
{
byte[] blob = new byte[KeyBlobMagic.Length + sizeof(int) + sizeof(int) + key.Length];
Buffer.BlockCopy(KeyBlobMagic, 0, blob, 0, KeyBlobMagic.Length);
Buffer.BlockCopy(BitConverter.GetBytes(1), 0, blob, KeyBlobMagic.Length, sizeof(int));
Buffer.BlockCopy(BitConverter.GetBytes(key.Length), 0, blob, KeyBlobMagic.Length + sizeof(int), sizeof(int));
Buffer.BlockCopy(key, 0, blob, KeyBlobMagic.Length + (sizeof(int) * 2), key.Length);
return blob;
}
private sealed class AuthInfo : IDisposable
{
internal BCryptAuthenticatedCipherModeInfo Info;
private GCHandle _nonceHandle;
private GCHandle _aadHandle;
private GCHandle _tagHandle;
private GCHandle _macHandle;
private byte[] _tagBuffer;
internal AuthInfo(byte[] nonce, byte[] aad, byte[] tag)
{
Info = new BCryptAuthenticatedCipherModeInfo();
Info.cbSize = Marshal.SizeOf(typeof(BCryptAuthenticatedCipherModeInfo));
Info.dwInfoVersion = 1;
if (nonce != null && nonce.Length > 0)
{
byte[] nonceCopy = (byte[])nonce.Clone();
_nonceHandle = GCHandle.Alloc(nonceCopy, GCHandleType.Pinned);
Info.pbNonce = _nonceHandle.AddrOfPinnedObject();
Info.cbNonce = nonceCopy.Length;
}
if (aad != null && aad.Length > 0)
{
byte[] aadCopy = (byte[])aad.Clone();
_aadHandle = GCHandle.Alloc(aadCopy, GCHandleType.Pinned);
Info.pbAuthData = _aadHandle.AddrOfPinnedObject();
Info.cbAuthData = aadCopy.Length;
Info.cbAAD = aadCopy.Length;
}
if (tag != null && tag.Length > 0)
{
_tagBuffer = (byte[])tag.Clone();
_tagHandle = GCHandle.Alloc(_tagBuffer, GCHandleType.Pinned);
Info.pbTag = _tagHandle.AddrOfPinnedObject();
Info.cbTag = _tagBuffer.Length;
byte[] mac = new byte[_tagBuffer.Length];
_macHandle = GCHandle.Alloc(mac, GCHandleType.Pinned);
Info.pbMacContext = _macHandle.AddrOfPinnedObject();
Info.cbMacContext = mac.Length;
}
}
internal void CopyTag(byte[] destination)
{
if (_tagBuffer != null && destination != null)
{
Buffer.BlockCopy(_tagBuffer, 0, destination, 0, Math.Min(_tagBuffer.Length, destination.Length));
}
}
public void Dispose()
{
if (_macHandle.IsAllocated) _macHandle.Free();
if (_tagHandle.IsAllocated) _tagHandle.Free();
if (_aadHandle.IsAllocated) _aadHandle.Free();
if (_nonceHandle.IsAllocated) _nonceHandle.Free();
}
}
[StructLayout(LayoutKind.Sequential)]
private struct BCryptAuthenticatedCipherModeInfo
{
internal int cbSize;
internal int dwInfoVersion;
internal IntPtr pbNonce;
internal int cbNonce;
internal IntPtr pbAuthData;
internal int cbAuthData;
internal IntPtr pbTag;
internal int cbTag;
internal IntPtr pbMacContext;
internal int cbMacContext;
internal int cbAAD;
internal long cbData;
internal int dwFlags;
}
private sealed class SafeAlgorithmHandle : SafeHandleZeroOrMinusOneIsInvalid
{
internal SafeAlgorithmHandle(IntPtr handle) : base(true)
{
SetHandle(handle);
}
protected override bool ReleaseHandle()
{
return BCryptCloseAlgorithmProvider(handle, 0) == ERROR_SUCCESS;
}
}
private sealed class SafeKeyHandle : SafeHandleZeroOrMinusOneIsInvalid
{
private readonly IntPtr _keyObject;
internal SafeKeyHandle(IntPtr handle, IntPtr keyObject) : base(true)
{
SetHandle(handle);
_keyObject = keyObject;
}
protected override bool ReleaseHandle()
{
if (_keyObject != IntPtr.Zero)
{
Marshal.FreeHGlobal(_keyObject);
}
return BCryptDestroyKey(handle) == ERROR_SUCCESS;
}
}
[DllImport("bcrypt.dll")]
private static extern uint BCryptOpenAlgorithmProvider(out IntPtr phAlgorithm, [MarshalAs(UnmanagedType.LPWStr)] string pszAlgId, [MarshalAs(UnmanagedType.LPWStr)] string pszImplementation, uint dwFlags);
[DllImport("bcrypt.dll")]
private static extern uint BCryptCloseAlgorithmProvider(IntPtr hAlgorithm, uint flags);
[DllImport("bcrypt.dll", EntryPoint = "BCryptGetProperty")]
private static extern uint BCryptGetProperty(IntPtr hObject, [MarshalAs(UnmanagedType.LPWStr)] string pszProperty, byte[] pbOutput, int cbOutput, ref int pcbResult, uint flags);
[DllImport("bcrypt.dll", EntryPoint = "BCryptSetProperty")]
private static extern uint BCryptSetAlgorithmProperty(IntPtr hObject, [MarshalAs(UnmanagedType.LPWStr)] string pszProperty, byte[] pbInput, int cbInput, int dwFlags);
[DllImport("bcrypt.dll")]
private static extern uint BCryptImportKey(IntPtr hAlgorithm, IntPtr hImportKey, [MarshalAs(UnmanagedType.LPWStr)] string pszBlobType, out IntPtr phKey, IntPtr pbKeyObject, int cbKeyObject, byte[] pbInput, int cbInput, uint dwFlags);
[DllImport("bcrypt.dll")]
private static extern uint BCryptDestroyKey(IntPtr hKey);
[DllImport("bcrypt.dll")]
private static extern uint BCryptEncrypt(IntPtr hKey, byte[] pbInput, int cbInput, ref BCryptAuthenticatedCipherModeInfo pPaddingInfo, byte[] pbIV, int cbIV, byte[] pbOutput, int cbOutput, ref int pcbResult, uint dwFlags);
[DllImport("bcrypt.dll")]
private static extern uint BCryptDecrypt(IntPtr hKey, byte[] pbInput, int cbInput, ref BCryptAuthenticatedCipherModeInfo pPaddingInfo, byte[] pbIV, int cbIV, byte[] pbOutput, int cbOutput, ref int pcbResult, uint dwFlags);
}
}
#endif