/// <summary>
/// Cosntructs a new SealBlockCipher with the specified arguments, the seal auth is requested from the user
/// on first use
/// </summary>
/// <param name="keyHandle"></param>
/// <param name="session"></param>
public SealBlockCipher(ClientKeyHandle keyHandle, TPMSession session, TPMPCRSelection pcrSelection)
{
_keyHandle = keyHandle;
_session = session;
_myId = session.GetFreeId();
_pcrSelection = pcrSelection;
_keyInfo = _keyHandle.KeyInfo;
}
/// <summary>
/// Cosntructs a new BindBlockCipher with the specified arguments, the seal auth is requested from the user
/// on first use
/// </summary>
/// <param name="keyHandle"></param>
/// <param name="session"></param>
public BindBlockCipher(ClientKeyHandle keyHandle, TPMSession session)
{
_keyHandle = keyHandle;
_session = session;
_keyInfo = _keyHandle.KeyInfo;
if (_keyInfo.KeyUsage != TPMKeyUsage.TPM_KEY_BIND)
{
throw new ArgumentException(string.Format("The key '{0}' is not a binding key!", keyHandle.FriendlyName));
}
}
/// <summary>
/// Verifies a signature generated on the tpm
/// </summary>
/// <param name="keyInfo">The key blob loaded into the tpm</param>
/// <param name="pubkey">the public key</param>
/// <param name="data">data to verify for integrity</param>
/// <param name="signature">signature to verify</param>
/// <returns></returns>
public static bool VerifySignature(TPMKey keyInfo, TPMPubkey pubkey, byte[] data, byte[] signature)
{
if (keyInfo.AlgorithmParams.SigScheme == TPMSigScheme.TPM_SS_RSASSAPKCS1v15_SHA1)
{
byte[] localDataDigest = new HashProvider().Hash(new HashByteDataProvider(data));
ISigner signatureVerificator = pubkey.CreateSignatureVerificator();
signatureVerificator.BlockUpdate(data, 0, data.Length);
return(signatureVerificator.VerifySignature(signature));
}
else
{
throw new NotSupportedException(string.Format("The signature scheme '{0}' is not supported", keyInfo.AlgorithmParams.SigScheme));
}
}
/// <summary>
/// Creates an ISigner for quoting using this key
/// </summary>
/// <param name="pcrSelection"></param>
/// <returns></returns>
public ISigner CreateQuoter(TPMPCRSelection pcrSelection)
{
TPMKey keyInfo = KeyInfo;
if (keyInfo.AlgorithmParams.AlgorithmId == TPMAlgorithmId.TPM_ALG_RSA &&
keyInfo.AlgorithmParams.SigScheme == TPMSigScheme.TPM_SS_RSASSAPKCS1v15_SHA1)
{
return(new QuoteSigner(_tpmSession, this, pcrSelection));
}
else
{
throw new NotSupportedException(string.Format("Quoter not supported for '{0}-{1}'", keyInfo.AlgorithmParams.AlgorithmId,
keyInfo.AlgorithmParams.SigScheme));
}
}
protected override TPMCommandResponse InternalProcess()
{
TPMBlob requestBlob = new TPMBlob();
requestBlob.WriteCmdHeader(TPMCmdTags.TPM_TAG_RQU_AUTH1_COMMAND, TPMOrdinals.TPM_ORD_Quote);
//key handle gets inserted later, it may be not available now
requestBlob.WriteUInt32(0);
requestBlob.Write(_nonce, 0, 20);
_pcrSelection.WriteToTpmBlob(requestBlob);
_keyManager.LoadKey(_params.GetValueOf <string>("key"));
AuthorizeMe(requestBlob);
using (_keyManager.AcquireLock())
{
requestBlob.SkipHeader();
requestBlob.WriteUInt32(_keyManager.IdentifierToHandle(_params.GetValueOf <string>("key")).Handle);
_responseBlob = TransmitMe(requestBlob);
}
CheckResponseAuthInfo();
_responseBlob.SkipHeader();
TPMPCRCompositeCore pcrComposite = TPMPCRCompositeCore.CreateFromTPMBlob(_responseBlob);
uint sigSize = _responseBlob.ReadUInt32();
byte[] signature = _responseBlob.ReadBytes((int)sigSize);
// Do signature verification
TPMQuoteInfoCore quoteInfo = TPMQuoteInfoCore.Create(new HashProvider().Hash(new HashTPMBlobWritableDataProvider(pcrComposite)), _nonce);
byte[] signingData;
using (TPMBlob blob = new TPMBlob())
{
quoteInfo.WriteToTpmBlob(blob);
signingData = blob.ToArray();
}
Parameters pubKeyParams = new Parameters();
pubKeyParams.AddPrimitiveType("key", _params.GetValueOf <string>("key"));
TPMCommandRequest pubKeyRequest = new TPMCommandRequest(TPMCommandNames.TPM_CMD_GetPubKey, pubKeyParams);
TPMCommandResponse pubKeyResponse = _tpmWrapper.Process(pubKeyRequest,
_commandAuthHelper, _keyManager);
if (pubKeyResponse.Status == false)
{
_log.FatalFormat("TPM_Quote: Could not retrieve pubkey of key");
return(new TPMCommandResponse(false, TPMCommandNames.TPM_CMD_Quote, new Parameters()));
}
TPMKey keyInfo = TPMKeyCore.CreateFromBytes(_keyManager.GetKeyBlob(_params.GetValueOf <string>("key")));
TPMPubkey pubkey = pubKeyResponse.Parameters.GetValueOf <TPMPubkey>("pubkey");
if (SignatureVerification.VerifySignature(keyInfo, pubkey, signingData, signature) == false)
{
throw new ArgumentException("The TPM_Quote signature could not be verified");
}
Parameters responseParams = new Parameters();
responseParams.AddValue("pcrData", pcrComposite);
responseParams.AddPrimitiveType("sig", signature);
return(new TPMCommandResponse(true, TPMCommandNames.TPM_CMD_Quote, responseParams));
}
protected override TPMCommandResponse InternalProcess()
{
string key = _params.GetValueOf <string>("key");
_keyManager.LoadKey(key);
TPMKey keyInfo = TPMKeyCore.CreateFromBytes(_keyManager.GetKeyBlob(key));
if (keyInfo == null)
{
throw new ArgumentException(string.Format("TPM_Sign could not retrieve keyinfo for key '{0}'", key));
}
byte[] areaToSign = null;
if (keyInfo.AlgorithmParams.SigScheme == TPMSigScheme.TPM_SS_RSASSAPKCS1v15_SHA1)
{
//Client has hopefully put data in the right format ready for the tpm to process
if (_params.IsDefined <byte[]>("areaToSign"))
{
areaToSign = _params.GetValueOf <byte[]>("areaToSign");
}
//Client just sends data, tpm lib cares about the right, signature dependent, processing
else if (_params.IsDefined <byte[]>("data"))
{
byte[] data = _params.GetValueOf <byte[]>("data");
areaToSign = new HashProvider().Hash(new HashByteDataProvider(data));
}
if (areaToSign.Length != 20)
{
throw new ArgumentException(string.Format("Sig scheme '{0}' expects an area to sign with length 20!", keyInfo.AlgorithmParams.SigScheme));
}
}
else
{
throw new ArgumentException(string.Format("TPM_Sign has not implemented signature scheme '{0}' for algorithm '{1}'", keyInfo.AlgorithmParams.SigScheme, keyInfo.AlgorithmParams.AlgorithmId));
}
TPMBlob requestBlob = new TPMBlob();
requestBlob.WriteCmdHeader(TPMCmdTags.TPM_TAG_RQU_AUTH1_COMMAND, TPMOrdinals.TPM_ORD_Sign);
//key handle gets inserted later, it may be not available now
requestBlob.WriteUInt32(0);
requestBlob.WriteUInt32((uint)areaToSign.Length);
requestBlob.Write(areaToSign, 0, areaToSign.Length);
AuthorizeMe(requestBlob);
using (_keyManager.AcquireLock())
{
requestBlob.SkipHeader();
requestBlob.WriteUInt32(_keyManager.IdentifierToHandle(key).Handle);
_responseBlob = TransmitMe(requestBlob);
}
CheckResponseAuthInfo();
_responseBlob.SkipHeader();
uint sigSize = _responseBlob.ReadUInt32();
byte[] signature = _responseBlob.ReadBytes((int)sigSize);
Parameters responseParams = new Parameters();
responseParams.AddPrimitiveType("sig", signature);
return(new TPMCommandResponse(true, TPMCommandNames.TPM_CMD_Sign, responseParams));
}
public override void Read(Stream src)
{
base.Read(src);
_tpmKey = StreamHelper.ReadTypedStreamSerializable <TPMKey>(src);
}
