/// <summary>
/// Create a new SymmCipher object with a random key based on the alg and mode supplied.
/// </summary>
/// <param name="algId"></param>
/// <param name="numBits"></param>
/// <param name="mode"></param>
/// <returns></returns>
public static SymmCipher Create(SymDefObject symDef = null, byte[] keyData = null, byte[] iv = null)
{
if (symDef == null)
{
symDef = new SymDefObject(TpmAlgId.Aes, 128, TpmAlgId.Cfb);
}
#if TSS_USE_BCRYPT
BCryptAlgorithm alg = null;
switch (symDef.Algorithm)
{
case TpmAlgId.Aes:
alg = new BCryptAlgorithm(Native.BCRYPT_AES_ALGORITHM);
break;
case TpmAlgId.Tdes:
alg = new BCryptAlgorithm(Native.BCRYPT_3DES_ALGORITHM);
break;
default:
Globs.Throw<ArgumentException>("Unsupported symmetric algorithm " + symDef.Algorithm);
break;
}
if (keyData == null)
{
keyData = Globs.GetRandomBytes(symDef.KeyBits / 8);
}
var key = alg.GenerateSymKey(symDef, keyData, GetBlockSize(symDef));
//key = BCryptInterface.ExportSymKey(keyHandle);
//keyHandle = alg.LoadSymKey(key, symDef, GetBlockSize(symDef));
alg.Close();
return key == null ? null : new SymmCipher(key, keyData, iv);
#else
SymmetricAlgorithm alg = null; // = new RijndaelManaged();
bool limitedSupport = false;
// DES and __3DES are not supported in TPM 2.0 rev. 0.96 to 1.30
switch (symDef.Algorithm) {
case TpmAlgId.Aes:
alg = new RijndaelManaged();
break;
case TpmAlgId.Tdes:
alg = new TripleDESCryptoServiceProvider();
limitedSupport = true;
break;
default:
Globs.Throw<ArgumentException>("Unsupported symmetric algorithm " + symDef.Algorithm);
break;
}
int blockSize = GetBlockSize(symDef);
alg.KeySize = symDef.KeyBits;
alg.BlockSize = blockSize * 8;
alg.Padding = PaddingMode.None;
alg.Mode = GetCipherMode(symDef.Mode);
// REVISIT: Get this right for other modes
if (symDef.Algorithm == TpmAlgId.Tdes && symDef.Mode == TpmAlgId.Cfb)
{
alg.FeedbackSize = 8;
}
else
{
alg.FeedbackSize = alg.BlockSize;
}
if (keyData == null)
{
// Generate random key
alg.IV = Globs.GetZeroBytes(blockSize);
try
{
alg.GenerateKey();
}
catch (Exception)
{
alg.Dispose();
throw;
}
}
else
{
// Use supplied key bits
alg.Key = keyData;
if (iv == null)
{
iv = Globs.GetZeroBytes(blockSize);
}
else if (iv.Length != blockSize)
{
Array.Resize(ref iv, blockSize);
}
alg.IV = iv;
}
var symCipher = new SymmCipher(alg);
symCipher.LimitedSupport = limitedSupport;
return symCipher;
#endif
}
/// <summary>
/// Create a new SymCipher object with a random key based on the alg and mode supplied.
/// </summary>
/// <param name="symDef"></param>
/// <param name="keyData"></param>
/// <param name="iv"></param>
/// <returns></returns>
public static SymCipher Create(SymDefObject symDef = null,
byte[] keyData = null, byte[] iv = null)
{
if (symDef == null)
{
symDef = new SymDefObject(TpmAlgId.Aes, 128, TpmAlgId.Cfb);
}
#if TSS_USE_BCRYPT
BCryptAlgorithm alg = null;
switch (symDef.Algorithm)
{
case TpmAlgId.Aes:
alg = new BCryptAlgorithm(Native.BCRYPT_AES_ALGORITHM);
break;
case TpmAlgId.Tdes:
alg = new BCryptAlgorithm(Native.BCRYPT_3DES_ALGORITHM);
break;
default:
Globs.Throw <ArgumentException>("Unsupported symmetric algorithm "
+ symDef.Algorithm);
return(null);
}
if (keyData == null)
{
keyData = Globs.GetRandomBytes(symDef.KeyBits / 8);
}
var key = alg.GenerateSymKey(symDef, keyData, GetBlockSize(symDef));
//key = BCryptInterface.ExportSymKey(keyHandle);
//keyHandle = alg.LoadSymKey(key, symDef, GetBlockSize(symDef));
alg.Close();
return(key == null ? null : new SymCipher(key, keyData, iv, GetBlockSize(symDef)));
#else // !TSS_USE_BCRYPT
if (symDef.Mode == TpmAlgId.Ofb)
{
return(null);
}
var mode = GetCipherMode(symDef.Mode);
if (mode == CipherMode_None)
{
return(null);
}
SymmetricAlgorithm alg = null; // = new RijndaelManaged();
bool limitedSupport = false;
int feedbackSize = 0;
switch (symDef.Algorithm)
{
case TpmAlgId.Aes:
alg = new RijndaelManaged();
alg.Mode = mode == CipherMode.CFB ? CipherMode.ECB : mode;
break;
case TpmAlgId.Tdes:
// DES and __3DES are not supported in TPM 2.0 rev. < 1.32
alg = new TripleDESCryptoServiceProvider();
alg.Mode = mode;
if (mode == CipherMode.CFB)
{
feedbackSize = 8;
}
limitedSupport = true;
break;
default:
//Globs.Throw<ArgumentException>("Unsupported symmetric algorithm " + symDef.Algorithm);
return(null);
}
int blockSize = GetBlockSize(symDef);
alg.KeySize = symDef.KeyBits;
alg.BlockSize = blockSize * 8;
alg.Padding = PaddingMode.None;
alg.FeedbackSize = feedbackSize == 0 ? alg.BlockSize : feedbackSize;
if (keyData == null)
{
// Generate random key
alg.IV = Globs.GetZeroBytes(blockSize);
try
{
alg.GenerateKey();
}
catch (Exception)
{
alg.Dispose();
throw;
}
}
else
{
// Use supplied key bits
alg.Key = keyData;
if (iv == null)
{
iv = Globs.GetZeroBytes(blockSize);
}
else if (iv.Length != blockSize)
{
Array.Resize(ref iv, blockSize);
}
alg.IV = iv;
}
var symCipher = new SymCipher(alg, mode);
symCipher.LimitedSupport = limitedSupport;
return(symCipher);
#endif // !TSS_USE_BCRYPT
} // Create()
/// <summary>
/// Create a new SymmCipher object with a random key based on the alg and mode supplied.
/// </summary>
/// <param name="algId"></param>
/// <param name="numBits"></param>
/// <param name="mode"></param>
/// <returns></returns>
public static SymmCipher Create(SymDefObject symDef = null, byte[] keyData = null, byte[] iv = null)
{
if (symDef == null)
{
symDef = new SymDefObject(TpmAlgId.Aes, 128, TpmAlgId.Cfb);
}
else if (symDef.Algorithm != TpmAlgId.Aes)
{
Globs.Throw <ArgumentException>("Unsupported symmetric algorithm " + symDef.Algorithm);
return(null);
}
#if TSS_USE_BCRYPT
var alg = new BCryptAlgorithm(Native.BCRYPT_AES_ALGORITHM);
if (keyData == null)
{
keyData = Globs.GetRandomBytes(symDef.KeyBits / 8);
}
var key = alg.GenerateSymKey(symDef, keyData, GetBlockSize(symDef));
//key = BCryptInterface.ExportSymKey(keyHandle);
//keyHandle = alg.LoadSymKey(key, symDef, GetBlockSize(symDef));
alg.Close();
return(new SymmCipher(key, keyData, iv));
#else
SymmetricAlgorithm alg = new RijndaelManaged();
// DES and __3DES are not supported in TPM 2.0 v 0.96 and above
//switch (algId) {
// case TpmAlgId.Aes: alg = new RijndaelManaged(); break;
// case TpmAlgId.__3DES: alg = new TripleDESCryptoServiceProvider(); break;
// case TpmAlgId.Des: alg = new DESCryptoServiceProvider(); break;
//}
int blockSize = GetBlockSize(symDef);
alg.KeySize = symDef.KeyBits;
alg.BlockSize = blockSize * 8;
alg.Padding = PaddingMode.None;
alg.Mode = GetCipherMode(symDef.Mode);
// REVISIT: Get this right for other modes
alg.FeedbackSize = alg.BlockSize;
if (keyData == null)
{
// Generate random key
alg.IV = Globs.GetZeroBytes(blockSize);
try
{
alg.GenerateKey();
}
catch (Exception)
{
alg.Dispose();
throw;
}
}
else
{
// Use supplied key bits
alg.Key = keyData;
if (iv == null)
{
iv = Globs.GetZeroBytes(blockSize);
}
else if (iv.Length != blockSize)
{
Array.Resize(ref iv, blockSize);
}
alg.IV = iv;
}
return(new SymmCipher(alg));
#endif
}
