// 'pbNonce' must point to a 96-bit buffer.
// 'pbTag' must point to a 128-bit buffer.
// 'pbEncryptedData' must point to a buffer the same length as 'pbPlaintextData'.
private void DoGcmEncrypt(byte *pbKey, uint cbKey, byte *pbNonce, byte *pbPlaintextData, uint cbPlaintextData, byte *pbEncryptedData, byte *pbTag)
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO authCipherInfo;
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Init(out authCipherInfo);
authCipherInfo.pbNonce = pbNonce;
authCipherInfo.cbNonce = NONCE_SIZE_IN_BYTES;
authCipherInfo.pbTag = pbTag;
authCipherInfo.cbTag = TAG_SIZE_IN_BYTES;
using (var keyHandle = _symmetricAlgorithmHandle.GenerateSymmetricKey(pbKey, cbKey))
{
uint cbResult;
var ntstatus = UnsafeNativeMethods.BCryptEncrypt(
hKey: keyHandle,
pbInput: pbPlaintextData,
cbInput: cbPlaintextData,
pPaddingInfo: &authCipherInfo,
pbIV: null,
cbIV: 0,
pbOutput: pbEncryptedData,
cbOutput: cbPlaintextData,
pcbResult: out cbResult,
dwFlags: 0);
UnsafeNativeMethods.ThrowExceptionForBCryptStatus(ntstatus);
CryptoUtil.Assert(cbResult == cbPlaintextData, "cbResult == cbPlaintextData");
}
}
public static unsafe void Decrypt(
SafeKeyHandle keyHandle,
ReadOnlySpan <byte> nonce,
ReadOnlySpan <byte> associatedData,
ReadOnlySpan <byte> ciphertext,
ReadOnlySpan <byte> tag,
Span <byte> plaintext,
bool clearPlaintextOnFailure)
{
// bcrypt sometimes misbehaves when given nullptr buffers; ensure non-nullptr
fixed(byte *plaintextBytes = &GetNonNullPinnableReference(plaintext))
fixed(byte *nonceBytes = &GetNonNullPinnableReference(nonce))
fixed(byte *ciphertextBytes = &GetNonNullPinnableReference(ciphertext))
fixed(byte *tagBytes = &GetNonNullPinnableReference(tag))
fixed(byte *associatedDataBytes = &GetNonNullPinnableReference(associatedData))
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
authInfo.pbNonce = nonceBytes;
authInfo.cbNonce = nonce.Length;
authInfo.pbTag = tagBytes;
authInfo.cbTag = tag.Length;
authInfo.pbAuthData = associatedDataBytes;
authInfo.cbAuthData = associatedData.Length;
NTSTATUS ntStatus = BCryptDecrypt(
keyHandle,
ciphertextBytes,
ciphertext.Length,
new IntPtr(&authInfo),
null,
0,
plaintextBytes,
plaintext.Length,
out int plaintextBytesWritten,
0);
Debug.Assert(ciphertext.Length == plaintextBytesWritten);
switch (ntStatus)
{
case NTSTATUS.STATUS_SUCCESS:
return;
case NTSTATUS.STATUS_AUTH_TAG_MISMATCH:
if (clearPlaintextOnFailure)
{
CryptographicOperations.ZeroMemory(plaintext);
}
throw new CryptographicException(SR.Cryptography_AuthTagMismatch);
default:
throw CreateCryptographicException(ntStatus);
}
}
}
public static extern uint BCryptEncrypt(IntPtr hKey,
byte[] pbInput,
int cbInput,
ref BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO pPaddingInfo,
byte[] pbIV, int cbIV,
byte[] pbOutput,
int cbOutput,
ref int pcbResult,
uint dwFlags);
public static unsafe void Decrypt(
SafeAlgorithmHandle algorithm,
SafeKeyHandleBCrypt keyHandle,
ReadOnlySpan <byte> nonce,
ReadOnlySpan <byte> associatedData,
ReadOnlySpan <byte> ciphertext,
ReadOnlySpan <byte> tag,
Span <byte> plaintext,
bool clearPlaintextOnFailure)
{
fixed(byte *plaintextBytes = plaintext)
fixed(byte *nonceBytes = nonce)
fixed(byte *ciphertextBytes = ciphertext)
fixed(byte *tagBytes = tag)
fixed(byte *associatedDataBytes = associatedData)
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
authInfo.pbNonce = nonceBytes;
authInfo.cbNonce = nonce.Length;
authInfo.pbTag = tagBytes;
authInfo.cbTag = tag.Length;
authInfo.pbAuthData = associatedDataBytes;
authInfo.cbAuthData = associatedData.Length;
NTSTATUS ntStatus = Cng.Interop.BCryptDecrypt(
keyHandle,
ciphertextBytes,
ciphertext.Length,
new IntPtr(&authInfo),
null,
0,
plaintextBytes,
plaintext.Length,
out int plaintextBytesWritten,
0);
Debug.Assert(ciphertext.Length == plaintextBytesWritten);
switch (ntStatus)
{
case NTSTATUS.STATUS_SUCCESS:
return;
case NTSTATUS.STATUS_AUTH_TAG_MISMATCH:
if (clearPlaintextOnFailure)
{
CryptographicOperations.ZeroMemory(plaintext);
}
throw new CryptographicException(SR.Cryptography_AuthTagMismatch);
default:
throw CreateCryptographicException(ntStatus);
}
}
}
public void IntPtrStructPropertyAccessor()
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO s = default(BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO);
s.pbAuthData_IntPtr = IntPtr.Zero;
BCRYPT_OAEP_PADDING_INFO oaep = default(BCRYPT_OAEP_PADDING_INFO);
oaep.pbLabel_IntPtr = IntPtr.Zero;
}
// corresponds to the BCRYPT_INIT_AUTH_MODE_INFO macro in bcrypt.h
public static void Init(out BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO info)
{
const uint BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO_VERSION = 1;
info = new BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO
{
cbSize = (uint)sizeof(BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO),
dwInfoVersion = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO_VERSION
};
}
public static BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO Create()
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO ret = new BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO();
ret.cbSize = sizeof(BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO);
const uint BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO_VERSION = 1;
ret.dwInfoVersion = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO_VERSION;
return(ret);
}
internal static unsafe void Encrypt(
SafeKeyHandle keyHandle,
byte[] nonce,
byte[] associatedData,
byte[] plaintext,
byte[] ciphertext,
byte[] tag)
{
fixed(byte *plaintextBytes = plaintext)
fixed(byte *nonceBytes = nonce)
fixed(byte *ciphertextBytes = ciphertext)
fixed(byte *tagBytes = tag)
fixed(byte *associatedDataBytes = associatedData)
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
authInfo.pbNonce = nonceBytes;
authInfo.cbNonce = nonce.Length;
authInfo.pbTag = tagBytes;
authInfo.cbTag = tag.Length;
authInfo.pbAuthData = associatedDataBytes;
if (associatedData == null)
{
authInfo.cbAuthData = 0;
}
else
{
authInfo.cbAuthData = associatedData.Length;
}
NTSTATUS ntStatus = Interop.BCrypt.BCryptEncrypt(
keyHandle,
plaintextBytes,
plaintext.Length,
new IntPtr(&authInfo),
null,
0,
ciphertextBytes,
ciphertext.Length,
out int ciphertextBytesWritten,
0);
Debug.Assert(plaintext.Length == ciphertextBytesWritten);
if (ntStatus != NTSTATUS.STATUS_SUCCESS)
{
throw Interop.BCrypt.CreateCryptographicException(ntStatus);
}
}
}
public static unsafe void Encrypt(
SafeKeyHandle keyHandle,
ReadOnlySpan <byte> nonce,
ReadOnlySpan <byte> associatedData,
ReadOnlySpan <byte> plaintext,
Span <byte> ciphertext,
Span <byte> tag)
{
// bcrypt sometimes misbehaves when given nullptr buffers; ensure non-nullptr
fixed(byte *plaintextBytes = &GetNonNullPinnableReference(plaintext))
fixed(byte *nonceBytes = &GetNonNullPinnableReference(nonce))
fixed(byte *ciphertextBytes = &GetNonNullPinnableReference(ciphertext))
fixed(byte *tagBytes = &GetNonNullPinnableReference(tag))
fixed(byte *associatedDataBytes = &GetNonNullPinnableReference(associatedData))
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
authInfo.pbNonce = nonceBytes;
authInfo.cbNonce = nonce.Length;
authInfo.pbTag = tagBytes;
authInfo.cbTag = tag.Length;
authInfo.pbAuthData = associatedDataBytes;
authInfo.cbAuthData = associatedData.Length;
NTSTATUS ntStatus = BCryptEncrypt(
keyHandle,
plaintextBytes,
plaintext.Length,
new IntPtr(&authInfo),
null,
0,
ciphertextBytes,
ciphertext.Length,
out int ciphertextBytesWritten,
0);
Debug.Assert(plaintext.Length == ciphertextBytesWritten);
if (ntStatus != NTSTATUS.STATUS_SUCCESS)
{
throw CreateCryptographicException(ntStatus);
}
}
}
public static unsafe void Encrypt(
SafeAlgorithmHandle algorithm,
SafeKeyHandle keyHandle,
ReadOnlySpan <byte> nonce,
ReadOnlySpan <byte> associatedData,
ReadOnlySpan <byte> plaintext,
Span <byte> ciphertext,
Span <byte> tag)
{
fixed(byte *plaintextBytes = plaintext)
fixed(byte *nonceBytes = nonce)
fixed(byte *ciphertextBytes = ciphertext)
fixed(byte *tagBytes = tag)
fixed(byte *associatedDataBytes = associatedData)
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
authInfo.pbNonce = nonceBytes;
authInfo.cbNonce = nonce.Length;
authInfo.pbTag = tagBytes;
authInfo.cbTag = tag.Length;
authInfo.pbAuthData = associatedDataBytes;
authInfo.cbAuthData = associatedData.Length;
NTSTATUS ntStatus = BCryptEncrypt(
keyHandle,
plaintextBytes,
plaintext.Length,
new IntPtr(&authInfo),
null,
0,
ciphertextBytes,
ciphertext.Length,
out int ciphertextBytesWritten,
0);
Debug.Assert(plaintext.Length == ciphertextBytesWritten);
if (ntStatus != NTSTATUS.STATUS_SUCCESS)
{
throw CreateCryptographicException(ntStatus);
}
}
}
public unsafe void Encrypt(ref WritableBuffer buffer, ReadableBuffer plainText, RecordType recordType)
{
var cInfo = new BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO();
cInfo.dwInfoVersion = 1;
cInfo.cbSize = sizeof(BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO);
cInfo.cbNonce = _iVLength;
cInfo.pbNonce = _ivPointer;
var iv = stackalloc byte[_blockLength];
var macRecord = stackalloc byte[_maxTagLength];
var tag = stackalloc byte[_overhead];
cInfo.dwFlags = AuthenticatedCipherModeInfoFlags.ChainCalls;
cInfo.cbMacContext = _maxTagLength;
cInfo.pbMacContext = (IntPtr)macRecord;
cInfo.pbTag = (IntPtr)tag;
cInfo.cbTag = _overhead;
cInfo.pbAuthData = _ivPointer;
cInfo.cbAuthData = 0;
var totalDataLength = plainText.Length;
int outLength;
GCHandle inHandle, outHandle;
foreach (var b in plainText)
{
totalDataLength = totalDataLength - b.Length;
if (b.Length == 0 && totalDataLength > 0)
{
continue;
}
buffer.Ensure(b.Length);
var inPtr = b.GetPointer(out inHandle);
var outPtr = buffer.Memory.GetPointer(out outHandle);
try
{
outLength = buffer.Memory.Length;
int amountWritten;
Interop.Windows.ExceptionHelper.CheckReturnCode(BCryptEncrypt(_key, inPtr, b.Length, &cInfo, iv, _blockLength, outPtr, b.Length, out amountWritten, 0));
cInfo.dwFlags = AuthenticatedCipherModeInfoFlags.InProgress;
buffer.Advance(amountWritten);
}
finally
{
if (inHandle.IsAllocated)
{
inHandle.Free();
}
if (outHandle.IsAllocated)
{
outHandle.Free();
}
}
if (totalDataLength == 0)
{
break;
}
}
buffer.Ensure(Overhead + sizeof(RecordType));
var writePtr = buffer.Memory.GetPointer(out outHandle);
outLength = buffer.Memory.Length;
if (_paddingSize == 0)
{
cInfo.dwFlags = AuthenticatedCipherModeInfoFlags.None;
}
Interop.Windows.ExceptionHelper.CheckReturnCode(BCryptEncrypt(_key, &recordType, sizeof(RecordType), &cInfo, iv, _iVLength, writePtr, buffer.Memory.Length, out outLength, 0));
buffer.Advance(outLength);
if (_paddingSize > 0)
{
outLength = _paddingSize;
writePtr = buffer.Memory.GetPointer(out outHandle);
cInfo.dwFlags = AuthenticatedCipherModeInfoFlags.None;
Interop.Windows.ExceptionHelper.CheckReturnCode(BCryptEncrypt(_key, (void *)s_zeroBuffer, _paddingSize, &cInfo, iv, _iVLength, writePtr, buffer.Memory.Length, out outLength, 0));
buffer.Advance(outLength);
}
writePtr = buffer.Memory.GetPointer(out outHandle);
buffer.Write(new Span <byte>(tag, _overhead));
buffer.Advance(_overhead);
}
protected override byte[] DecryptImpl(byte *pbCiphertext, uint cbCiphertext, byte *pbAdditionalAuthenticatedData, uint cbAdditionalAuthenticatedData)
{
// Argument checking: input must at the absolute minimum contain a key modifier, nonce, and tag
if (cbCiphertext < KEY_MODIFIER_SIZE_IN_BYTES + NONCE_SIZE_IN_BYTES + TAG_SIZE_IN_BYTES)
{
throw Error.CryptCommon_PayloadInvalid();
}
// Assumption: pbCipherText := { keyModifier || nonce || encryptedData || authenticationTag }
var cbPlaintext = checked (cbCiphertext - (KEY_MODIFIER_SIZE_IN_BYTES + NONCE_SIZE_IN_BYTES + TAG_SIZE_IN_BYTES));
var retVal = new byte[cbPlaintext];
fixed(byte *pbRetVal = retVal)
{
// Calculate offsets
byte *pbKeyModifier = pbCiphertext;
byte *pbNonce = &pbKeyModifier[KEY_MODIFIER_SIZE_IN_BYTES];
byte *pbEncryptedData = &pbNonce[NONCE_SIZE_IN_BYTES];
byte *pbAuthTag = &pbEncryptedData[cbPlaintext];
// Use the KDF to recreate the symmetric block cipher key
// We'll need a temporary buffer to hold the symmetric encryption subkey
byte *pbSymmetricDecryptionSubkey = stackalloc byte[checked ((int)_symmetricAlgorithmSubkeyLengthInBytes)];
try
{
_sp800_108_ctr_hmac_provider.DeriveKeyWithContextHeader(
pbLabel: pbAdditionalAuthenticatedData,
cbLabel: cbAdditionalAuthenticatedData,
contextHeader: _contextHeader,
pbContext: pbKeyModifier,
cbContext: KEY_MODIFIER_SIZE_IN_BYTES,
pbDerivedKey: pbSymmetricDecryptionSubkey,
cbDerivedKey: _symmetricAlgorithmSubkeyLengthInBytes);
// Perform the decryption operation
using (var decryptionSubkeyHandle = _symmetricAlgorithmHandle.GenerateSymmetricKey(pbSymmetricDecryptionSubkey, _symmetricAlgorithmSubkeyLengthInBytes))
{
byte dummy;
byte *pbPlaintext = (pbRetVal != null) ? pbRetVal : &dummy; // CLR doesn't like pinning empty buffers
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO authInfo;
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Init(out authInfo);
authInfo.pbNonce = pbNonce;
authInfo.cbNonce = NONCE_SIZE_IN_BYTES;
authInfo.pbTag = pbAuthTag;
authInfo.cbTag = TAG_SIZE_IN_BYTES;
// The call to BCryptDecrypt will also validate the authentication tag
uint cbDecryptedBytesWritten;
var ntstatus = UnsafeNativeMethods.BCryptDecrypt(
hKey: decryptionSubkeyHandle,
pbInput: pbEncryptedData,
cbInput: cbPlaintext,
pPaddingInfo: &authInfo,
pbIV: null, // IV not used; nonce provided in pPaddingInfo
cbIV: 0,
pbOutput: pbPlaintext,
cbOutput: cbPlaintext,
pcbResult: out cbDecryptedBytesWritten,
dwFlags: 0);
UnsafeNativeMethods.ThrowExceptionForBCryptStatus(ntstatus);
CryptoUtil.Assert(cbDecryptedBytesWritten == cbPlaintext, "cbDecryptedBytesWritten == cbPlaintext");
// At this point, retVal := { decryptedPayload }
// And we're done!
return(retVal);
}
}
finally
{
// The buffer contains key material, so delete it.
UnsafeBufferUtil.SecureZeroMemory(pbSymmetricDecryptionSubkey, _symmetricAlgorithmSubkeyLengthInBytes);
}
}
}
public unsafe void EncryptDecrypt_AesCcm()
{
var random = new Random();
using (var provider = BCryptOpenAlgorithmProvider(AlgorithmIdentifiers.BCRYPT_AES_ALGORITHM))
{
BCryptSetProperty(provider, PropertyNames.BCRYPT_CHAINING_MODE, ChainingModes.Ccm);
byte[] plainText;
byte[] cipherText;
var nonceBuffer = new byte[12];
random.NextBytes(nonceBuffer);
var tagLengths = BCryptGetProperty <BCRYPT_AUTH_TAG_LENGTHS_STRUCT>(provider, PropertyNames.BCRYPT_AUTH_TAG_LENGTH);
var tagBuffer = new byte[tagLengths.MaxLength];
int blockSize = BCryptGetProperty <int>(provider, PropertyNames.BCRYPT_BLOCK_LENGTH);
plainText = new byte[blockSize];
random.NextBytes(plainText);
byte[] keyMaterial = new byte[blockSize];
RandomNumberGenerator.Create().GetBytes(keyMaterial);
using (var key = BCryptGenerateSymmetricKey(provider, keyMaterial))
{
var authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
fixed(byte *pTagBuffer = &tagBuffer[0])
fixed(byte *pNonce = &nonceBuffer[0])
{
authInfo.pbNonce = pNonce;
authInfo.cbNonce = nonceBuffer.Length;
authInfo.pbTag = pTagBuffer;
authInfo.cbTag = tagBuffer.Length;
// Mix up calling the IntPtr and native pointer overloads so we test both.
int cipherTextLength;
BCryptEncrypt(key, plainText, plainText.Length, &authInfo, null, 0, null, 0, out cipherTextLength, BCryptEncryptFlags.None).ThrowOnError();
cipherText = new byte[cipherTextLength];
BCryptEncrypt(key, plainText, plainText.Length, &authInfo, null, 0, cipherText, cipherText.Length, out cipherTextLength, BCryptEncryptFlags.None).ThrowOnError();
}
Assert.NotEqual <byte>(plainText, cipherText);
}
// Renew the key to prove we can decrypt it with a fresh key.
using (var key = BCryptGenerateSymmetricKey(provider, keyMaterial))
{
byte[] decryptedText;
var authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
fixed(byte *pTagBuffer = &tagBuffer[0])
fixed(byte *pNonce = &nonceBuffer[0])
{
authInfo.pbNonce = pNonce;
authInfo.cbNonce = nonceBuffer.Length;
authInfo.pbTag = pTagBuffer;
authInfo.cbTag = tagBuffer.Length;
int plainTextLength;
BCryptDecrypt(key, cipherText, cipherText.Length, &authInfo, null, 0, null, 0, out plainTextLength, BCryptEncryptFlags.None).ThrowOnError();
decryptedText = new byte[plainTextLength];
BCryptEncrypt(key, cipherText, cipherText.Length, &authInfo, null, 0, decryptedText, decryptedText.Length, out plainTextLength, BCryptEncryptFlags.None).ThrowOnError();
Array.Resize(ref decryptedText, plainTextLength);
}
Assert.Equal <byte>(plainText, decryptedText);
}
}
}
/// <summary>
/// Encrypts the data using AES-GCM
/// </summary>
/// <param name="pbData">data to encrypt</param>
/// <param name="pbKey">key to use for encryption</param>
/// <param name="pbNonce">GCM nonce</param>
/// <param name="pbTag">GCM authentication tag</param>
/// <param name="pbAuthData">associated autentication data</param>
/// <returns>the encrypted data</returns>
public unsafe static byte[] GcmEncrypt(byte[] pbData, byte[] pbKey, byte[] pbNonce, byte[] pbTag, byte[] pbAuthData = null)
{
pbAuthData = pbAuthData ?? new byte[0];
NTSTATUS status = 0;
using (var provider = BCryptOpenAlgorithmProvider(AlgorithmIdentifiers.BCRYPT_AES_ALGORITHM))
{
BCryptSetProperty(provider, PropertyNames.BCRYPT_CHAINING_MODE, ChainingModes.Gcm);
var tagLengths = BCryptGetProperty <BCRYPT_AUTH_TAG_LENGTHS_STRUCT>(provider, PropertyNames.BCRYPT_AUTH_TAG_LENGTH);
if (pbTag.Length < tagLengths.dwMinLength ||
pbTag.Length > tagLengths.dwMaxLength ||
(pbTag.Length - tagLengths.dwMinLength) % tagLengths.dwIncrement != 0)
{
throw new ArgumentException("Invalid tag length");
}
using (var key = BCryptGenerateSymmetricKey(provider, pbKey))
{
var authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
fixed(byte *pTagBuffer = pbTag)
fixed(byte *pNonce = pbNonce)
fixed(byte *pAuthData = pbAuthData)
{
authInfo.pbNonce = pNonce;
authInfo.cbNonce = pbNonce.Length;
authInfo.pbTag = pTagBuffer;
authInfo.cbTag = pbTag.Length;
authInfo.pbAuthData = pAuthData;
authInfo.cbAuthData = pbAuthData.Length;
// Initialize cipher text byte count
int pcbCipherText = pbData.Length;
// Allocate cipher text buffer
byte[] pbCipherText = new byte[pcbCipherText];
fixed(byte *plainText = pbData)
fixed(byte *cipherText = pbCipherText)
{
// Encrypt the data
status = BCryptEncrypt(
key,
plainText,
pbData.Length,
&authInfo,
null,
0,
cipherText,
pbCipherText.Length,
out pcbCipherText,
0);
}
if (status != NTSTATUS.Code.STATUS_SUCCESS)
{
throw new CryptographicException($"BCryptEncrypt failed result {status:X} ");
}
return(pbCipherText);
}
}
}
}
public unsafe void EncryptWithAuthData(ref WritableBuffer buffer, RecordType recordType, ushort tlsVersion, int plaintextLength)
{
var additionalData = stackalloc byte[13];
var additionalSpan = new Span <byte>(additionalData, 13);
additionalSpan.Write64BitNumber(_sequenceNumber);
additionalSpan = additionalSpan.Slice(8);
additionalSpan.Write(recordType);
additionalSpan = additionalSpan.Slice(1);
additionalSpan.Write(tlsVersion);
additionalSpan = additionalSpan.Slice(2);
additionalSpan.Write16BitNumber((ushort)plaintextLength);
var cInfo = new BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO();
cInfo.dwInfoVersion = 1;
cInfo.cbSize = Marshal.SizeOf <BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO>();
cInfo.cbNonce = _iVLength;
cInfo.pbNonce = _ivPointer;
cInfo.dwFlags = AuthenticatedCipherModeInfoFlags.ChainCalls;
cInfo.pbAuthData = (IntPtr)additionalData;
cInfo.cbAuthData = 13;
var iv = stackalloc byte[16];
var macRecord = stackalloc byte[16];
var tag = stackalloc byte[16];
cInfo.cbMacContext = 16;
cInfo.pbMacContext = (IntPtr)macRecord;
cInfo.pbTag = (IntPtr)tag;
cInfo.cbTag = 16;
//var totalDataLength = plainText.Length;
//foreach (var b in plainText)
//{
// totalDataLength = totalDataLength - b.Length;
// if (b.Length == 0 && totalDataLength > 0)
// {
// continue;
// }
// if (totalDataLength == 0)
// {
// cInfo.dwFlags = AuthenticatedCipherModeInfoFlags.None;
// }
// buffer.Ensure(b.Length);
// void* outPointer;
// if (!buffer.Memory.TryGetPointer(out outPointer))
// {
// throw new NotImplementedException("Need to implement a pinned array if we can get a pointer");
// }
// void* inPointer;
// if (!b.TryGetPointer(out inPointer))
// {
// throw new NotImplementedException("Need to implement a pinned array if we can't get a pointer");
// }
// int amountWritten;
// Interop.Windows.ExceptionHelper.CheckReturnCode(
// BCryptEncrypt(_key, inPointer, b.Length, &cInfo, iv, 16, outPointer, buffer.Memory.Length, out amountWritten, 0));
// buffer.Advance(amountWritten);
// cInfo.dwFlags = AuthenticatedCipherModeInfoFlags.InProgress;
// if (totalDataLength == 0)
// {
// break;
// }
//}
//buffer.Ensure(16);
//buffer.Write(new Span<byte>(tag, 16));
//IncrementSequence();
//_sequenceNumber++;
}
internal static extern uint BCryptDecrypt(IntPtr hKey,
byte[] pbInput,
int cbInput,
ref BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO pPaddingInfo,
byte[] pbIV,
int cbIV,
byte[] pbOutput,
int cbOutput,
ref int pcbResult,
int dwFlags);
public static unsafe void Decrypt(
SafeKeyHandle keyHandle,
byte[] nonce,
byte[] associatedData,
byte[] ciphertext,
byte[] tag,
byte[] plaintext,
bool clearPlaintextOnFailure)
{
fixed(byte *plaintextBytes = plaintext)
fixed(byte *nonceBytes = nonce)
fixed(byte *ciphertextBytes = ciphertext)
fixed(byte *tagBytes = tag)
fixed(byte *associatedDataBytes = associatedData)
{
BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO authInfo = BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO.Create();
authInfo.pbNonce = nonceBytes;
authInfo.cbNonce = nonce.Length;
authInfo.pbTag = tagBytes;
authInfo.cbTag = tag.Length;
authInfo.pbAuthData = associatedDataBytes;
if (associatedData == null)
{
authInfo.cbAuthData = 0;
}
else
{
authInfo.cbAuthData = associatedData.Length;
}
NTSTATUS ntStatus = Interop.BCrypt.BCryptDecrypt(
keyHandle,
ciphertextBytes,
ciphertext.Length,
new IntPtr(&authInfo),
null,
0,
plaintextBytes,
plaintext.Length,
out int plaintextBytesWritten,
0);
Debug.Assert(ciphertext.Length == plaintextBytesWritten);
switch (ntStatus)
{
case NTSTATUS.STATUS_SUCCESS:
return;
case NTSTATUS.STATUS_AUTH_TAG_MISMATCH:
if (clearPlaintextOnFailure)
{
CryptographicOperations.ZeroMemory(plaintext);
}
throw LogHelper.LogExceptionMessage(new CryptographicException(LogHelper.FormatInvariant(LogMessages.IDX10714)));
default:
throw LogHelper.LogExceptionMessage(Interop.BCrypt.CreateCryptographicException(ntStatus));
}
}
}