public byte[] EncryptDecrypt(byte[] data, bool decrypt, ref byte[] ivIn, out byte[] ivOut)
{
ivOut = null;
if (Public.type != TpmAlgId.Symcipher)
{
Globs.Throw <ArgumentException>("Only symmetric encryption/decryption is "
+ "supported by this overloaded version");
return(null);
}
var symDef = GetSymDef();
using (var sym = SymCipher.Create(symDef,
(Sensitive.sensitive as Tpm2bSymKey).buffer))
{
if (sym == null)
{
Globs.Throw <ArgumentException>("Unsupported symmetric key configuration");
return(null);
}
if (Globs.IsEmpty(ivIn))
{
ivIn = (symDef.Mode == TpmAlgId.Ecb) ? new byte[0]
: Globs.GetRandomBytes(SymCipher.GetBlockSize(symDef));
}
ivOut = Globs.CopyData(ivIn);
return(decrypt ? sym.Decrypt(data, ivOut)
: sym.Encrypt(data, ivOut));
}
} // EncryptDecrypt
/// <summary>
/// Creates a Private area for this key so that it can be loaded into a TPM by
/// TPM2_Load() if the target TPM already has the storage key 'parent' loaded.
/// This function lets an application to create key hierarchies in software
/// that can be loaded into a TPM once the parent has been TPM2_Import'ed.
/// TPM2_Import() supports plaintext import. To get this sort of import blob,
/// set 'parent' to null.
/// </summary>
/// <param name="parent"></param>
/// <returns></returns>
public TpmPrivate GetPrivate(TssObject parent)
{
SymDefObject symDef = GetSymDef(parent.Public);
// Figure out how many bits we will need from the KDF
byte[] parentSymSeed = parent.Sensitive.seedValue;
Transform(parentSymSeed);
byte[] iv = (symDef.Mode == TpmAlgId.Ecb) ? new byte[0]
: Globs.GetRandomBytes(SymCipher.GetBlockSize(symDef));
// The encryption key is calculated with a KDF
byte[] symKey = KDF.KDFa(parent.Public.nameAlg,
parentSymSeed,
"STORAGE",
GetName(),
new byte[0],
symDef.KeyBits);
Transform(symKey);
byte[] newPrivate = KeyWrapper.CreatePrivateFromSensitive(
symDef,
symKey,
iv,
Sensitive,
Public.nameAlg,
Public.GetName(),
parent.Public.nameAlg,
parent.Sensitive.seedValue,
TransformerCallback);
Transform(newPrivate);
return(new TpmPrivate(newPrivate));
}
public static byte[] Decrypt(SymDefObject symDef, byte[] key, byte[] iv,
byte[] dataToDecrypt)
{
using (SymCipher cipher = Create(symDef, key, iv))
{
return(cipher.Decrypt(dataToDecrypt));
}
}
internal byte[] ParmEncrypt(byte[] parm, Direction inOrOut)
{
if (Symmetric == null)
{
Globs.Throw("parameter encryption cipher not defined");
return(parm);
}
if (Symmetric.Algorithm == TpmAlgId.Null)
{
return(parm);
}
byte[] nonceNewer, nonceOlder;
if (inOrOut == Direction.Command)
{
nonceNewer = NonceCaller;
nonceOlder = NonceTpm;
}
else
{
nonceNewer = NonceTpm;
nonceOlder = NonceCaller;
}
byte[] encKey = (AuthHandle != null && AuthHandle.Auth != null)
? SessionKey.Concat(Globs.TrimTrailingZeros(AuthHandle.Auth)).ToArray()
: SessionKey;
if (Symmetric.Algorithm == TpmAlgId.Xor)
{
return(CryptoLib.KdfThenXor(AuthHash, encKey, nonceNewer, nonceOlder, parm));
}
int keySize = (Symmetric.KeyBits + 7) / 8,
blockSize = SymCipher.GetBlockSize(Symmetric),
bytesRequired = keySize + blockSize;
byte[] keyInfo = KDF.KDFa(AuthHash, encKey, "CFB", nonceNewer, nonceOlder, bytesRequired * 8);
var key = new byte[keySize];
Array.Copy(keyInfo, 0, key, 0, keySize);
var iv = new byte[blockSize];
Array.Copy(keyInfo, keySize, iv, 0, blockSize);
// Make a new SymCipher from the key and IV and do the encryption.
using (SymCipher s = SymCipher.Create(Symmetric, key, iv))
{
return(inOrOut == Direction.Command ? s.Encrypt(parm) : s.Decrypt(parm));
}
}
/// <summary>
/// Create an enveloped (encrypted and integrity protected) private area from a provided sensitive.
/// </summary>
/// <param name="iv"></param>
/// <param name="sens"></param>
/// <param name="nameHash"></param>
/// <param name="publicName"></param>
/// <param name="symWrappingAlg"></param>
/// <param name="symKey"></param>
/// <param name="parentNameAlg"></param>
/// <param name="parentSeed"></param>
/// <param name="f"></param>
/// <returns></returns>
public static byte[] CreatePrivateFromSensitive(
SymDefObject symWrappingAlg,
byte[] symKey,
byte[] iv,
Sensitive sens,
TpmAlgId nameHash,
byte[] publicName,
TpmAlgId parentNameAlg,
byte[] parentSeed,
TssObject.Transformer f = null)
{
// ReSharper disable once InconsistentNaming
byte[] tpm2bIv = Marshaller.ToTpm2B(iv);
Transform(tpm2bIv, f);
byte[] sensitive = sens.GetTpmRepresentation();
Transform(sensitive, f);
// ReSharper disable once InconsistentNaming
byte[] tpm2bSensitive = Marshaller.ToTpm2B(sensitive);
Transform(tpm2bSensitive, f);
byte[] encSensitive = SymCipher.Encrypt(symWrappingAlg, symKey, iv, tpm2bSensitive);
Transform(encSensitive, f);
byte[] decSensitive = SymCipher.Decrypt(symWrappingAlg, symKey, iv, encSensitive);
Debug.Assert(f != null || Globs.ArraysAreEqual(decSensitive, tpm2bSensitive));
var hmacKeyBits = CryptoLib.DigestSize(parentNameAlg) * 8;
byte[] hmacKey = KDF.KDFa(parentNameAlg, parentSeed, "INTEGRITY", new byte[0], new byte[0], hmacKeyBits);
Transform(hmacKey, f);
byte[] dataToHmac = Marshaller.GetTpmRepresentation(tpm2bIv,
encSensitive,
publicName);
Transform(dataToHmac, f);
byte[] outerHmac = CryptoLib.Hmac(parentNameAlg, hmacKey, dataToHmac);
Transform(outerHmac, f);
byte[] priv = Marshaller.GetTpmRepresentation(Marshaller.ToTpm2B(outerHmac),
tpm2bIv,
encSensitive);
Transform(priv, f);
return(priv);
}
/// <summary>
/// De-envelope inner-wrapped duplication blob.
/// TODO: Move this to TpmPublic and make it fully general
/// </summary>
/// <param name="exportedPrivate"></param>
/// <param name="encAlg"></param>
/// <param name="encKey"></param>
/// <param name="nameAlg"></param>
/// <param name="name"></param>
/// <returns></returns>
public static Sensitive SensitiveFromDupBlob(TpmPrivate exportedPrivate,
SymDefObject encAlg, byte[] encKey,
TpmAlgId nameAlg, byte[] name)
{
byte[] dupBlob = exportedPrivate.buffer;
byte[] sensNoLen = null;
using (SymCipher c = Create(encAlg, encKey))
{
byte[] innerObject = null;
if (c == null)
{
if (encAlg.Algorithm != TpmAlgId.Null)
{
return(null);
}
else
{
return(Marshaller.FromTpmRepresentation <Sensitive>(Marshaller.Tpm2BToBuffer(dupBlob)));
}
}
innerObject = c.Decrypt(dupBlob);
byte[] innerIntegrity, sensitive;
KDF.Split(innerObject,
16 + CryptoLib.DigestSize(nameAlg) * 8,
out innerIntegrity,
8 * (innerObject.Length - CryptoLib.DigestSize(nameAlg) - 2),
out sensitive);
byte[] expectedInnerIntegrity = Marshaller.ToTpm2B(
CryptoLib.HashData(nameAlg, sensitive, name));
if (!Globs.ArraysAreEqual(expectedInnerIntegrity, innerIntegrity))
{
Globs.Throw("SensitiveFromDupBlob: Bad inner integrity");
}
sensNoLen = Marshaller.Tpm2BToBuffer(sensitive);
}
var sens = Marshaller.FromTpmRepresentation <Sensitive>(sensNoLen);
return(sens);
}
/// <summary>
/// Creates a duplication blob for the current key that can be Imported as a child
/// of newParent. Three forms are possible. GetPlaintextDuplicationBlob() allows
/// plaintext-import. This function enables duplication with and without an
/// inner wrapper (depending on whether innerWrapper is null)
/// </summary>
/// <param name="newParent"></param>
/// <param name="innerWrapper"></param>
/// <param name="encSecret"></param>
/// <returns></returns>
public TpmPrivate GetDuplicationBlob(
TpmPublic pubNewParent,
SymCipher innerWrapper,
out byte[] encSecret)
{
byte[] encSensitive;
if (innerWrapper == null)
{
// No inner wrapper
encSensitive = Marshaller.ToTpm2B(Sensitive.GetTpmRepresentation());
Transform(encSensitive);
}
else
{
byte[] sens = Marshaller.ToTpm2B(Sensitive.GetTpmRepresentation());
byte[] toHash = Globs.Concatenate(sens, GetName());
Transform(toHash);
byte[] innerIntegrity = Marshaller.ToTpm2B(CryptoLib.HashData(
Public.nameAlg, toHash));
byte[] innerData = Globs.Concatenate(innerIntegrity, sens);
Transform(innerData);
encSensitive = innerWrapper.Encrypt(innerData);
Transform(encSensitive);
}
byte[] seed;
SymDefObject symDef = GetSymDef(pubNewParent).Copy();
// TPM duplication procedures always use CFB mode
symDef.Mode = TpmAlgId.Cfb;
using (var swNewParent = AsymCryptoSystem.CreateFrom(pubNewParent))
{
switch (pubNewParent.type)
{
case TpmAlgId.Rsa:
// The seed should be the same size as the scheme hash
LastSeed =
seed = Globs.GetRandomBytes(
CryptoLib.DigestSize(swNewParent.OaepHash));
encSecret = swNewParent.EncryptOaep(seed, DuplicateEncodingParms);
break;
case TpmAlgId.Ecc:
EccPoint pubEphem;
seed = swNewParent.EcdhGetKeyExchangeKey(DuplicateEncodingParms,
pubNewParent.nameAlg,
out pubEphem);
encSecret = Marshaller.GetTpmRepresentation(pubEphem);
break;
default:
Globs.Throw <NotImplementedException>(
"GetDuplicationBlob: Unsupported algorithm");
encSecret = new byte[0];
return(new TpmPrivate());
}
}
Transform(seed);
Transform(encSecret);
byte[] symKey = KDF.KDFa(pubNewParent.nameAlg, seed, "STORAGE",
Public.GetName(), new byte[0], symDef.KeyBits);
Transform(symKey);
byte[] dupSensitive;
using (SymCipher enc2 = SymCipher.Create(symDef, symKey))
{
if (enc2 == null)
{
return(null);
}
dupSensitive = enc2.Encrypt(encSensitive);
}
Transform(dupSensitive);
var npNameNumBits = CryptoLib.DigestSize(pubNewParent.nameAlg) * 8;
byte[] hmacKey = KDF.KDFa(pubNewParent.nameAlg, seed, "INTEGRITY",
new byte[0], new byte[0], npNameNumBits);
byte[] outerDataToHmac = Globs.Concatenate(dupSensitive, Public.GetName());
Transform(outerDataToHmac);
byte[] outerHmac = Marshaller.ToTpm2B(CryptoLib.Hmac(pubNewParent.nameAlg,
hmacKey, outerDataToHmac));
Transform(outerHmac);
byte[] dupBlob = Globs.Concatenate(outerHmac, dupSensitive);
Transform(dupBlob);
return(new TpmPrivate(dupBlob));
}
/// <summary>
/// Create activation blobs that can be passed to ActivateCredential. Two
/// blobs are returned:
/// 1) encryptedSecret - symmetric key cfb-symmetrically encrypted with the
/// enveloping key;
/// 2) credentialBlob - the enveloping key OEAP (RSA) encrypted by the public
/// part of this key. This is the return value of this
/// function
/// </summary>
/// <param name="secret"></param>
/// <param name="nameOfKeyToBeActivated"></param>
/// <param name="encryptedSecret"></param>
/// <returns>CredentialBlob (</returns>
public IdObject CreateActivationCredentials(byte[] secret,
byte[] nameOfKeyToBeActivated,
out byte[] encryptedSecret)
{
byte[] seed, encSecret;
switch (type)
{
case TpmAlgId.Rsa:
// The seed should be the same size as the name algorithmdigest
seed = Globs.GetRandomBytes(CryptoLib.DigestSize(nameAlg));
encSecret = EncryptOaep(seed, ActivateEncodingParms);
break;
case TpmAlgId.Ecc:
EccPoint ephemPubPt;
seed = EcdhGetKeyExchangeKey(ActivateEncodingParms, out ephemPubPt);
encSecret = Marshaller.GetTpmRepresentation(ephemPubPt);
break;
default:
Globs.Throw <NotImplementedException>(
"CreateActivationCredentials: Unsupported algorithm");
encryptedSecret = new byte[0];
return(null);
}
Transform(seed);
Transform(encSecret);
var cvx = new Tpm2bDigest(secret);
byte[] cvTpm2B = Marshaller.GetTpmRepresentation(cvx);
Transform(cvTpm2B);
SymDefObject symDef = TssObject.GetSymDef(this);
byte[] symKey = KDF.KDFa(nameAlg, seed, "STORAGE",
nameOfKeyToBeActivated, new byte[0], symDef.KeyBits);
Transform(symKey);
byte[] encIdentity;
// TPM only uses CFB mode in its command implementations
var sd = symDef.Copy();
sd.Mode = TpmAlgId.Cfb;
using (var sym = SymCipher.Create(sd, symKey))
{
// Not all keys specs are supported by SW crypto
if (sym == null)
{
encryptedSecret = null;
return(null);
}
encIdentity = sym.Encrypt(cvTpm2B);
}
Transform(encIdentity);
var hmacKeyBits = CryptoLib.DigestSize(nameAlg);
byte[] hmacKey = KDF.KDFa(nameAlg, seed, "INTEGRITY",
new byte[0], new byte[0], hmacKeyBits * 8);
Transform(hmacKey);
byte[] outerHmac = CryptoLib.Hmac(nameAlg, hmacKey,
Globs.Concatenate(encIdentity, nameOfKeyToBeActivated));
Transform(outerHmac);
encryptedSecret = encSecret;
return(new IdObject(outerHmac, encIdentity));
}
/// <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()
