public TkVerified VerifySignatureOfRecivedMessage(TpmPublic keyPublic, byte[] message, ISignatureUnion signature)
{
TpmHash dataToSign = TpmHash.FromData(TpmAlgId.Sha256, message);
TpmHandle pubHandle = tpm.LoadExternal(null, keyPublic, TpmHandle.RhOwner);
return(tpm.VerifySignature(pubHandle, dataToSign.HashData, signature));
}
void EcdhSample(Tpm2 tpm, TestContext testCtx)
{
//
// Peer A (e.g. local machine):
//
// Template for an ECC key with the ECDH scheme:
var inPub = new TpmPublic(TpmAlgId.Sha256,
ObjectAttr.Decrypt | ObjectAttr.UserWithAuth | ObjectAttr.SensitiveDataOrigin,
null,
new EccParms(new SymDefObject(), new SchemeEcdh(TpmAlgId.Sha256),
EccCurve.NistP256, new NullKdfScheme()),
new EccPoint());
// Boilerplate stuff
var pcrSel = new PcrSelection[0];
CreationData crData;
byte[] crHash;
TkCreation crTk;
// Create a key for ECDH
TpmPublic pubA;
TpmHandle hKeyA = tpm.CreatePrimary(TpmRh.Owner, new SensitiveCreate(), inPub, null, new PcrSelection[0],
out pubA, out crData, out crHash, out crTk);
//
// Peer B (e.g. remote machine):
//
// Receives 'pubA' from peer A
// Load public key
TpmHandle hPubKeyA = tpm.LoadExternal(null, pubA, TpmRh.Owner);
// Create shared secret 'zB', and a public ECC point for exchange
EccPoint ephPubPt;
EccPoint zB = tpm.EcdhKeyGen(hPubKeyA, out ephPubPt);
tpm.FlushContext(hPubKeyA);
//
// Peer A again:
//
// Receives 'ephPubPt' from peer B
// A full key is required here
EccPoint zA = tpm.EcdhZGen(hKeyA, ephPubPt);
testCtx.AssertEqual("SharedSecret", zA, zB);
tpm.FlushContext(hKeyA);
} // EcdhSample
void LoadExternalFullRsaKeySample(Tpm2 tpm, TestContext testCtx)
{
var hashAlg = TpmAlgId.Sha256;
var inPub = new TpmPublic(hashAlg,
ObjectAttr.Decrypt | ObjectAttr.UserWithAuth | ObjectAttr.SensitiveDataOrigin,
null,
new RsaParms(new SymDefObject(), new SchemeOaep(hashAlg), 2048, 0),
new Tpm2bPublicKeyRsa());
// Create a software RSA key
var swKey = new AsymCryptoSystem(inPub);
// The crucial point in loading a software key is preparing the TPM-formatted private part of the key
Sensitive sens = swKey.GetSensitive();
TpmHandle extKey = tpm.LoadExternal(sens, swKey.GetPublicParms(), TpmRh.Null);
//
// Make sure that the key was loaded correctly
//
// This particular label is used by the TPM while doing OAEP for its internal protocols
// (though in n general any label can be used).
byte[] label = RawRsa.GetLabel("OaepLabel");
byte[] origMsg = Substrate.RandomBytes(64);
// Encrypt using software key (the paublic part is used)
byte[] encMsg = swKey.EncryptOaep(origMsg, label);
testCtx.AssertNotEqual("SwEnc", origMsg, encMsg);
// Decrypt using the TPM (the private part is used)
byte[] decMsg = tpm.RsaDecrypt(extKey, encMsg, null, label);
testCtx.AssertEqual("CrossEncDec", origMsg, decMsg);
tpm.FlushContext(extKey);
}
/// <summary>
/// This sample demonstrates the creation of a signing "primary" key and use of this
/// key to sign data, and use of the TPM and TSS.Net to validate the signature.
/// </summary>
/// <param name="args">Arguments to this program.</param>
static void Main(string[] args)
{
//
// Parse the program arguments. If the wrong arguments are given or
// are malformed, then instructions for usage are displayed and
// the program terminates.
//
string tpmDeviceName;
if (!ParseArguments(args, out tpmDeviceName))
{
WriteUsage();
return;
}
try
{
//
// Create the device according to the selected connection.
//
Tpm2Device tpmDevice;
switch (tpmDeviceName)
{
case DeviceSimulator:
tpmDevice = new TcpTpmDevice(DefaultSimulatorName, DefaultSimulatorPort);
break;
case DeviceWinTbs:
tpmDevice = new TbsDevice();
break;
default:
throw new Exception("Unknown device selected.");
}
//
// Connect to the TPM device. This function actually establishes the
// connection.
//
tpmDevice.Connect();
//
// Pass the device object used for communication to the TPM 2.0 object
// which provides the command interface.
//
var tpm = new Tpm2(tpmDevice);
if (tpmDevice is TcpTpmDevice)
{
//
// If we are using the simulator, we have to do a few things the
// firmware would usually do. These actions have to occur after
// the connection has been established.
//
tpmDevice.PowerCycle();
tpm.Startup(Su.Clear);
}
//
// AuthValue encapsulates an authorization value: essentially a byte-array.
// OwnerAuth is the owner authorization value of the TPM-under-test. We
// assume that it (and other) auths are set to the default (null) value.
// If running on a real TPM, which has been provisioned by Windows, this
// value will be different. An administrator can retrieve the owner
// authorization value from the registry.
//
var ownerAuth = new AuthValue();
//
// The TPM needs a template that describes the parameters of the key
// or other object to be created. The template below instructs the TPM
// to create a new 2048-bit non-migratable signing key.
//
var keyTemplate = new TpmPublic(TpmAlgId.Sha1, // Name algorithm
ObjectAttr.UserWithAuth | ObjectAttr.Sign | // Signing key
ObjectAttr.FixedParent | ObjectAttr.FixedTPM | // Non-migratable
ObjectAttr.SensitiveDataOrigin,
null, // No policy
new RsaParms(new SymDefObject(),
new SchemeRsassa(TpmAlgId.Sha1), 2048, 0),
new Tpm2bPublicKeyRsa());
//
// Authorization for the key we are about to create.
//
var keyAuth = new byte[] { 1, 2, 3 };
TpmPublic keyPublic;
CreationData creationData;
TkCreation creationTicket;
byte[] creationHash;
//
// Ask the TPM to create a new primary RSA signing key.
//
TpmHandle keyHandle = tpm[ownerAuth].CreatePrimary(
TpmRh.Owner, // In the owner-hierarchy
new SensitiveCreate(keyAuth, null), // With this auth-value
keyTemplate, // Describes key
null, // Extra data for creation ticket
new PcrSelection[0], // Non-PCR-bound
out keyPublic, // PubKey and attributes
out creationData, out creationHash, out creationTicket); // Not used here
//
// Print out text-versions of the public key just created
//
Console.WriteLine("New public key\n" + keyPublic.ToString());
//
// Use the key to sign some data
//
byte[] message = Encoding.Unicode.GetBytes("ABC");
TpmHash digestToSign = TpmHash.FromData(TpmAlgId.Sha1, message);
//
// A different structure is returned for each signing scheme,
// so cast the interface to our signature type (see third argument).
//
// As an alternative, 'signature' can be of type ISignatureUnion and
// cast to SignatureRssa whenever a signature specific type is needed.
//
var signature = tpm[keyAuth].Sign(keyHandle, // Handle of signing key
digestToSign, // Data to sign
null, // Use key's scheme
TpmHashCheck.Null()) as SignatureRsassa;
//
// Print the signature.
//
Console.WriteLine("Signature: " + BitConverter.ToString(signature.sig));
//
// Use the TPM library to validate the signature
//
bool sigOk = keyPublic.VerifySignatureOverData(message, signature);
if (!sigOk)
{
throw new Exception("Signature did not validate.");
}
Console.WriteLine("Verified signature with TPM2lib (software implementation).");
//
// Load the public key into another slot in the TPM and then
// use the TPM to validate the signature
//
TpmHandle pubHandle = tpm.LoadExternal(null, keyPublic, TpmRh.Owner);
tpm.VerifySignature(pubHandle, digestToSign, signature);
Console.WriteLine("Verified signature with TPM.");
//
// The default behavior of Tpm2Lib is to create an exception if the
// signature does not validate. If an error is expected the library can
// be notified of this, or the exception can be turned into a value that
// can be later queried. The following are examples of this.
//
signature.sig[0] ^= 1;
tpm._ExpectError(TpmRc.Signature)
.VerifySignature(pubHandle, digestToSign, signature);
if (tpm._GetLastResponseCode() != TpmRc.Signature)
{
throw new Exception("TPM returned unexpected return code.");
}
Console.WriteLine("Verified that invalid signature causes TPM_RC_SIGNATURE return code.");
//
// Clean up of used handles.
//
tpm.FlushContext(keyHandle);
tpm.FlushContext(pubHandle);
//
// (Note that serialization is not supported on WinRT)
//
// Demonstrate the use of XML persistence by saving keyPublic to
// a file and making a copy by reading it back into a new object
//
// NOTE: 12-JAN-2016: May be removing support for policy
// serialization. We'd like to get feedback on whether
// this is a desirable feature and should be retained.
//
// {
// const string fileName = "sample.xml";
// string xmlVersionOfObject = keyPublic.GetXml();
// keyPublic.XmlSerializeToFile(fileName);
// var copyOfPublic = TpmStructureBase.XmlDeserializeFromFile<TpmPublic>(fileName);
//
// //
// // Demonstrate Tpm2Lib support of TPM-structure equality operators
// //
// if (copyOfPublic != keyPublic)
// {
// Console.WriteLine("Library bug persisting data.");
// }
// }
//
//
// Clean up.
//
tpm.Dispose();
}
catch (Exception e)
{
Console.WriteLine("Exception occurred: {0}", e.Message);
}
Console.WriteLine("Press Any Key to continue.");
Console.ReadLine();
}
static void Sign()
{
using (Tpm2Device tpmDevice = Examples.GetSimulator())
{
tpmDevice.Connect();
using (var tpm = new Tpm2(tpmDevice))
{
if (tpmDevice is TcpTpmDevice)
{
tpmDevice.PowerCycle();
}
CreateRsaPrimaryKey(tpm, tpmDevice is TcpTpmDevice);
var keyTemplate = new TpmPublic(TpmAlgId.Sha1, // Name algorithm
ObjectAttr.UserWithAuth | ObjectAttr.Sign | // Signing key
ObjectAttr.FixedParent | ObjectAttr.FixedTPM | // Non-migratable
ObjectAttr.SensitiveDataOrigin,
null, // No policy
new RsaParms(new SymDefObject(),
new SchemeRsassa(TpmAlgId.Sha1), 2048, 0),
new Tpm2bPublicKeyRsa());
var ownerAuth = new AuthValue();
var keyAuth = new byte[] { 1, 2, 3 };
TpmPublic keyPublic;
CreationData creationData;
TkCreation creationTicket;
byte[] creationHash;
TpmHandle keyHandle = tpm[ownerAuth].CreatePrimary(
TpmRh.Owner, // In the owner-hierarchy
new SensitiveCreate(keyAuth, null), // With this auth-value
keyTemplate, // Describes key
null, // Extra data for creation ticket
new PcrSelection[0], // Non-PCR-bound
out keyPublic, // PubKey and attributes
out creationData, out creationHash, out creationTicket); // Not used here
//
// Print out text-versions of the public key just created
//
Console.WriteLine("New public key\n" + keyPublic.ToString());
byte[] message = Encoding.Unicode.GetBytes("ABC");
TpmHash digestToSign = TpmHash.FromData(TpmAlgId.Sha1, message);
var signature = tpm[keyAuth].Sign(keyHandle, // Handle of signing key
digestToSign, // Data to sign
null, // Use key's scheme
TpmHashCheck.Null()) as SignatureRsassa;
//
// Print the signature.
//
Console.WriteLine("Signature: " + BitConverter.ToString(signature.sig));
bool sigOk = keyPublic.VerifySignatureOverData(message, signature);
if (!sigOk)
{
throw new Exception("Signature did not validate.");
}
Console.WriteLine("Verified signature with TPM2lib (software implementation).");
TpmHandle pubHandle = tpm.LoadExternal(null, keyPublic, TpmRh.Owner);
tpm.VerifySignature(pubHandle, digestToSign, signature);
Console.WriteLine("Verified signature with TPM.");
}
}
}
