internal static Microsoft.Win32.SafeHandles.SafeCspHandle AcquireCsp(string keyContainer,
string providerName,
ProviderType providerType,
CryptAcquireContextFlags flags,
bool throwPlatformException)
{
Contract.Ensures(Contract.Result <SafeCspHandle>() != null &&
!Contract.Result <SafeCspHandle>().IsInvalid&&
!Contract.Result <SafeCspHandle>().IsClosed);
Microsoft.Win32.SafeHandles.SafeCspHandle cspHandle = null;
if (!UnsafeNativeMethods.CryptAcquireContext(out cspHandle,
keyContainer,
providerName,
providerType,
flags))
{
// If the platform doesn't have the specified CSP, we'll either get a ProviderTypeNotDefined
// or a KeysetNotDefined error depending on the CAPI version.
int error = Marshal.GetLastWin32Error();
if (throwPlatformException && (error == (int)CapiNative.ErrorCode.ProviderTypeNotDefined ||
error == (int)CapiNative.ErrorCode.KeysetNotDefined))
{
throw new PlatformNotSupportedException(SR.GetString(SR.Cryptography_PlatformNotSupported));
}
else
{
throw new CryptographicException(error);
}
}
return(cspHandle);
}
public AesCryptoServiceProvider () {
Contract.Ensures(m_cspHandle != null && !m_cspHandle.IsInvalid && !m_cspHandle.IsClosed);
// On Windows XP the AES CSP has the prototype name, but on newer operating systems it has the
// standard name
string providerName = CapiNative.ProviderNames.MicrosoftEnhancedRsaAes;
if (Environment.OSVersion.Version.Major == 5 && Environment.OSVersion.Version.Minor == 1) {
providerName = CapiNative.ProviderNames.MicrosoftEnhancedRsaAesPrototype;
}
m_cspHandle = CapiNative.AcquireCsp(null,
providerName,
CapiNative.ProviderType.RsaAes,
CapiNative.CryptAcquireContextFlags.VerifyContext,
true);
// CAPI will not allow feedback sizes greater than 64 bits
FeedbackSizeValue = 8;
// Get the different AES key sizes supported by this platform, raising an error if there are no
// supported key sizes.
int defaultKeySize = 0;
KeySizes[] keySizes = FindSupportedKeySizes(m_cspHandle, out defaultKeySize);
if (keySizes.Length != 0) {
Debug.Assert(defaultKeySize > 0, "defaultKeySize > 0");
KeySizeValue = defaultKeySize;
}
else {
throw new PlatformNotSupportedException(SR.GetString(SR.Cryptography_PlatformNotSupported));
}
}
public SafeCspHandle Duplicate()
{
Contract.Requires(!IsInvalid && !IsClosed);
// In the window between the call to CryptContextAddRef and when the raw handle value is assigned
// into this safe handle, there's a second reference to the original safe handle that the CLR does
// not know about, so we need to bump the reference count around this entire operation to ensure
// that we don't have the original handle closed underneath us.
bool acquired = false;
RuntimeHelpers.PrepareConstrainedRegions();
try
{
DangerousAddRef(ref acquired);
IntPtr originalHandle = DangerousGetHandle();
int error = (int)CapiNative.ErrorCode.Success;
SafeCspHandle duplicate = new SafeCspHandle();
// A successful call to CryptContextAddRef and an assignment of the handle value to the duplicate
// SafeHandle need to happen atomically, so we contain them within a CER.
RuntimeHelpers.PrepareConstrainedRegions();
try { }
finally
{
if (!CryptContextAddRef(this, IntPtr.Zero, 0))
{
error = Marshal.GetLastWin32Error();
}
else
{
duplicate.SetHandle(originalHandle);
}
}
// If we could not call CryptContextAddRef succesfully, then throw the error here otherwise
// we should be in a valid state at this point.
if (error != (int)CapiNative.ErrorCode.Success)
{
duplicate.Dispose();
throw new CryptographicException(error);
}
else
{
Debug.Assert(!duplicate.IsInvalid, "Failed to duplicate handle successfully");
}
return(duplicate);
}
finally
{
if (acquired)
{
DangerousRelease();
}
}
}
internal static T GetProviderParameterStruct <T>(Microsoft.Win32.SafeHandles.SafeCspHandle provider,
ProviderParameter parameter,
ProviderParameterFlags flags) where T : struct
{
Contract.Requires(provider != null);
Contract.Requires(parameter == ProviderParameter.EnumerateAlgorithms);
// Figure out how big the parameter is
int bufferSize = 0;
IntPtr buffer = IntPtr.Zero;
if (!UnsafeNativeMethods.CryptGetProvParam(provider, parameter, buffer, ref bufferSize, flags))
{
int errorCode = Marshal.GetLastWin32Error();
// NoMoreItems means that we've finished the enumeration we're currently working on, this is
// not a real error, so return an empty structure to mark the end.
if (errorCode == (int)ErrorCode.NoMoreItems)
{
return(new T());
}
else if (errorCode != (int)ErrorCode.MoreData)
{
throw new CryptographicException(errorCode);
}
}
Debug.Assert(Marshal.SizeOf(typeof(T)) <= bufferSize, "Buffer size does not match structure size");
//
// Pull the parameter back and marshal it into the return structure
//
RuntimeHelpers.PrepareConstrainedRegions();
try {
// Allocate in a CER because we could fail between the alloc and the assignment
RuntimeHelpers.PrepareConstrainedRegions();
try { }
finally {
buffer = Marshal.AllocCoTaskMem(bufferSize);
}
if (!UnsafeNativeMethods.CryptGetProvParam(provider, parameter, buffer, ref bufferSize, flags))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
return((T)Marshal.PtrToStructure(buffer, typeof(T)));
}
finally {
if (buffer != IntPtr.Zero)
{
Marshal.FreeCoTaskMem(buffer);
}
}
}
// SafeCritical - we're not exposing out anything that we want to prevent untrusted code from getting at
public CapiHashAlgorithm(string provider,
CapiNative.ProviderType providerType,
CapiNative.AlgorithmId algorithm) {
Contract.Requires(!String.IsNullOrEmpty(provider));
Contract.Requires((CapiNative.AlgorithmClass)((uint)algorithm & (uint)CapiNative.AlgorithmClass.Hash) == CapiNative.AlgorithmClass.Hash);
Contract.Ensures(m_cspHandle != null && !m_cspHandle.IsInvalid && !m_cspHandle.IsClosed);
Contract.Ensures(m_hashHandle != null && !m_hashHandle.IsInvalid && !m_hashHandle.IsClosed);
m_algorithmId = algorithm;
m_cspHandle = CapiNative.AcquireCsp(null,
provider,
providerType,
CapiNative.CryptAcquireContextFlags.VerifyContext,
true);
Initialize();
}
// SafeCritical - we're not exposing out anything that we want to prevent untrusted code from getting at
public CapiHashAlgorithm(string provider,
CapiNative.ProviderType providerType,
CapiNative.AlgorithmId algorithm)
{
Contract.Requires(!String.IsNullOrEmpty(provider));
Contract.Requires((CapiNative.AlgorithmClass)((uint)algorithm & (uint)CapiNative.AlgorithmClass.Hash) == CapiNative.AlgorithmClass.Hash);
Contract.Ensures(m_cspHandle != null && !m_cspHandle.IsInvalid && !m_cspHandle.IsClosed);
Contract.Ensures(m_hashHandle != null && !m_hashHandle.IsInvalid && !m_hashHandle.IsClosed);
m_algorithmId = algorithm;
m_cspHandle = CapiNative.AcquireCsp(null,
provider,
providerType,
CapiNative.CryptAcquireContextFlags.VerifyContext,
true);
Initialize();
}
internal void SetParentCsp(SafeCspHandle parentCsp)
{
bool addedRef = false;
RuntimeHelpers.PrepareConstrainedRegions();
try {
parentCsp.DangerousAddRef(ref addedRef);
IntPtr rawParentHandle = parentCsp.DangerousGetHandle();
ParentCsp = rawParentHandle;
}
finally {
if (addedRef)
{
parentCsp.DangerousRelease();
}
}
}
public SafeCspHandle Duplicate()
{
SafeCspHandle handle2;
bool success = false;
RuntimeHelpers.PrepareConstrainedRegions();
try
{
base.DangerousAddRef(ref success);
IntPtr ptr = base.DangerousGetHandle();
int hr = 0;
SafeCspHandle handle = new SafeCspHandle();
RuntimeHelpers.PrepareConstrainedRegions();
try
{
}
finally
{
if (!CryptContextAddRef(this, IntPtr.Zero, 0))
{
hr = Marshal.GetLastWin32Error();
}
else
{
handle.SetHandle(ptr);
}
}
if (hr != 0)
{
handle.Dispose();
throw new CryptographicException(hr);
}
handle2 = handle;
}
finally
{
if (success)
{
base.DangerousRelease();
}
}
return handle2;
}
public CapiSymmetricAlgorithm(int blockSize,
int feedbackSize,
Microsoft.Win32.SafeHandles.SafeCspHandle provider,
SafeCapiKeyHandle key,
byte[] iv,
CipherMode cipherMode,
PaddingMode paddingMode,
EncryptionMode encryptionMode) {
Contract.Requires(0 < blockSize && blockSize % 8 == 0);
Contract.Requires(0 <= feedbackSize);
Contract.Requires(provider != null && !provider.IsInvalid && !provider.IsClosed);
Contract.Requires(key != null && !key.IsInvalid && !key.IsClosed);
Contract.Ensures(m_provider != null && !m_provider.IsInvalid && !m_provider.IsClosed);
m_blockSize = blockSize;
m_encryptionMode = encryptionMode;
m_paddingMode = paddingMode;
m_provider = provider.Duplicate();
m_key = SetupKey(key, ProcessIV(iv, blockSize, cipherMode), cipherMode, feedbackSize);
}
public CapiSymmetricAlgorithm(int blockSize,
int feedbackSize,
Microsoft.Win32.SafeHandles.SafeCspHandle provider,
SafeCapiKeyHandle key,
byte[] iv,
CipherMode cipherMode,
PaddingMode paddingMode,
EncryptionMode encryptionMode)
{
Contract.Requires(0 < blockSize && blockSize % 8 == 0);
Contract.Requires(0 <= feedbackSize);
Contract.Requires(provider != null && !provider.IsInvalid && !provider.IsClosed);
Contract.Requires(key != null && !key.IsInvalid && !key.IsClosed);
Contract.Ensures(m_provider != null && !m_provider.IsInvalid && !m_provider.IsClosed);
m_blockSize = blockSize;
m_encryptionMode = encryptionMode;
m_paddingMode = paddingMode;
m_provider = provider.Duplicate();
m_key = SetupKey(key, ProcessIV(iv, blockSize, cipherMode), cipherMode, feedbackSize);
}
public AesCryptoServiceProvider()
{
Contract.Ensures(m_cspHandle != null && !m_cspHandle.IsInvalid && !m_cspHandle.IsClosed);
// On Windows XP the AES CSP has the prototype name, but on newer operating systems it has the
// standard name
string providerName = CapiNative.ProviderNames.MicrosoftEnhancedRsaAes;
if (Environment.OSVersion.Version.Major == 5 && Environment.OSVersion.Version.Minor == 1)
{
providerName = CapiNative.ProviderNames.MicrosoftEnhancedRsaAesPrototype;
}
m_cspHandle = CapiNative.AcquireCsp(null,
providerName,
CapiNative.ProviderType.RsaAes,
CapiNative.CryptAcquireContextFlags.VerifyContext,
true);
// CAPI will not allow feedback sizes greater than 64 bits
FeedbackSizeValue = 8;
// Get the different AES key sizes supported by this platform, raising an error if there are no
// supported key sizes.
int defaultKeySize = 0;
KeySizes[] keySizes = FindSupportedKeySizes(m_cspHandle, out defaultKeySize);
if (keySizes.Length != 0)
{
Debug.Assert(defaultKeySize > 0, "defaultKeySize > 0");
KeySizeValue = defaultKeySize;
}
else
{
throw new PlatformNotSupportedException(SR.GetString(SR.Cryptography_PlatformNotSupported));
}
}
public static extern bool CryptImportKey(Microsoft.Win32.SafeHandles.SafeCspHandle hProv,
[MarshalAs(UnmanagedType.LPArray)] byte[] pbData,
int dwDataLen,
SafeCapiKeyHandle hPubKey,
KeyFlags dwFlags,
[Out] out SafeCapiKeyHandle phKey);
public static extern bool CryptGetProvParam(Microsoft.Win32.SafeHandles.SafeCspHandle hProv,
ProviderParameter dwParam,
IntPtr pbData,
[In, Out] ref int pdwDataLen,
ProviderParameterFlags dwFlags);
public static extern bool CryptGenRandom(Microsoft.Win32.SafeHandles.SafeCspHandle hProv,
int dwLen,
[Out, MarshalAs(UnmanagedType.LPArray)] byte[] pbBuffer);
public static extern bool CryptGenKey(Microsoft.Win32.SafeHandles.SafeCspHandle hProv,
AlgorithmId Algid,
KeyFlags dwFlags,
[Out] out SafeCapiKeyHandle phKey);
public static extern bool CryptCreateHash(Microsoft.Win32.SafeHandles.SafeCspHandle hProv,
AlgorithmId Algid,
SafeCapiKeyHandle hKey,
int dwFlags,
[Out] out SafeCapiHashHandle phHash);
internal static SafeCapiKeyHandle ImportSymmetricKey(Microsoft.Win32.SafeHandles.SafeCspHandle provider, AlgorithmId algorithm, byte[] key)
{
Contract.Requires(provider != null);
Contract.Requires(((int)algorithm & (int)AlgorithmClass.DataEncryption) == (int)AlgorithmClass.DataEncryption);
Contract.Requires(key != null);
Contract.Ensures(Contract.Result <SafeCapiKeyHandle>() != null &&
!Contract.Result <SafeCapiKeyHandle>().IsInvalid&&
!Contract.Result <SafeCapiKeyHandle>().IsClosed);
//
// Setup a PLAINTEXTKEYBLOB (v2) which has the following format:
// BLOBHEADER hdr
// DWORD cbKeySize
// BYTE rbgKeyData[]
//
int blobSize = Marshal.SizeOf(typeof(BLOBHEADER)) + Marshal.SizeOf(typeof(int)) + key.Length;
byte[] keyBlob = new byte[blobSize];
unsafe
{
fixed(byte *pBlob = keyBlob)
{
BLOBHEADER *pHeader = (BLOBHEADER *)pBlob;
pHeader->bType = KeyBlobType.PlainText;
pHeader->bVersion = 2;
pHeader->reserved = 0;
pHeader->aiKeyAlg = algorithm;
int *pSize = (int *)(pBlob + Marshal.SizeOf(*pHeader));
*pSize = key.Length;
}
}
Buffer.BlockCopy(key, 0, keyBlob, Marshal.SizeOf(typeof(BLOBHEADER)) + Marshal.SizeOf(typeof(int)), key.Length);
// Import the PLAINTEXTKEYBLOB into the CSP
SafeCapiKeyHandle importedKey = null;
RuntimeHelpers.PrepareConstrainedRegions();
try {
if (!UnsafeNativeMethods.CryptImportKey(provider,
keyBlob,
keyBlob.Length,
SafeCapiKeyHandle.InvalidHandle,
KeyFlags.Exportable,
out importedKey))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
}
finally {
if (importedKey != null && !importedKey.IsInvalid)
{
importedKey.SetParentCsp(provider);
}
}
return(importedKey);
}
private static extern bool CryptContextAddRef(SafeCspHandle hProv, IntPtr pdwReserved, int dwFlags);
public static extern bool CryptAcquireContext([Out] out Microsoft.Win32.SafeHandles.SafeCspHandle phProv,
string pszContainer,
string pszProvider,
ProviderType dwProvType,
CryptAcquireContextFlags dwFlags);
private static KeySizes[] FindSupportedKeySizes(Microsoft.Win32.SafeHandles.SafeCspHandle csp, out int defaultKeySize)
{
Contract.Requires(csp != null);
Contract.Ensures(Contract.Result <KeySizes[]>() != null);
// If this platform has any supported algorithm sizes, then the default key size should be set to a
// reasonable value.
Contract.Ensures(Contract.Result <KeySizes[]>().Length == 0 ||
(Contract.ValueAtReturn <int>(out defaultKeySize) > 0 && Contract.ValueAtReturn <int>(out defaultKeySize) % 8 == 0));
if (s_supportedKeySizes == null)
{
List <KeySizes> keySizes = new List <KeySizes>();
int maxKeySize = 0;
//
// Enumerate the CSP's supported algorithms to see what key sizes it supports for AES
//
CapiNative.PROV_ENUMALGS algorithm =
CapiNative.GetProviderParameterStruct <CapiNative.PROV_ENUMALGS>(csp,
CapiNative.ProviderParameter.EnumerateAlgorithms,
CapiNative.ProviderParameterFlags.RestartEnumeration);
// Translate between CAPI AES algorithm IDs and supported key sizes
while (algorithm.aiAlgId != CapiNative.AlgorithmId.None)
{
switch (algorithm.aiAlgId)
{
case CapiNative.AlgorithmId.Aes128:
keySizes.Add(new KeySizes(128, 128, 0));
if (128 > maxKeySize)
{
maxKeySize = 128;
}
break;
case CapiNative.AlgorithmId.Aes192:
keySizes.Add(new KeySizes(192, 192, 0));
if (192 > maxKeySize)
{
maxKeySize = 192;
}
break;
case CapiNative.AlgorithmId.Aes256:
keySizes.Add(new KeySizes(256, 256, 0));
if (256 > maxKeySize)
{
maxKeySize = 256;
}
break;
default:
break;
}
algorithm = CapiNative.GetProviderParameterStruct <CapiNative.PROV_ENUMALGS>(csp,
CapiNative.ProviderParameter.EnumerateAlgorithms,
CapiNative.ProviderParameterFlags.None);
}
s_supportedKeySizes = keySizes.ToArray();
s_defaultKeySize = maxKeySize;
}
defaultKeySize = s_defaultKeySize;
return(s_supportedKeySizes);
}
