public SerializeToFile ( string policyIdentifier, PolicySerializationFormat fmt, string fileName ) : void | ||
policyIdentifier | string | |
fmt | PolicySerializationFormat | |
fileName | string | |
return | void |
/// <summary> /// This sample demonstrates a policy containing ALL policy commands. /// It also demonstrates serialization of the policy, and the use /// of callbacks to satisfy the conditions in a policy (e.g. knowledge /// of a private key, or the NV-index associated with a name. /// </summary> /// <param name="tpm">Reference to the TPM used.</param> static void SamplePolicySerializationAndCallbacks(Tpm2 tpm) { Console.WriteLine("Policy sample that serializes all policy commands."); // // Check if policy commands are implemented by TPM. This list // could include all the other used commands as well. // This check here makes sense for policy commands, because // usually a policy has to be executed in full. If a command // out of the chain of policy commands is not implemented in the // TPM, the policy cannot be satisfied. // var usedCommands = new[] { TpmCc.PolicyPhysicalPresence, TpmCc.PolicySigned, TpmCc.PolicySecret, TpmCc.PolicyPCR, TpmCc.PolicyLocality, TpmCc.PolicyNV, TpmCc.PolicyCounterTimer, TpmCc.PolicyCommandCode, TpmCc.PolicyPassword, TpmCc.PolicyAuthorize, TpmCc.PolicyPhysicalPresence, TpmCc.PolicyCpHash, TpmCc.PolicyTicket, TpmCc.PolicyNameHash, TpmCc.PolicyCpHash, TpmCc.PolicyDuplicationSelect, TpmCc.PolicyAuthValue, TpmCc.PolicyNvWritten }; foreach (var commandCode in usedCommands) { if (!tpm.Helpers.IsImplemented(commandCode)) { Console.WriteLine("Cancel Policy serialization and callback sample, because command {0} is not implemented by TPM.", commandCode); return; } } // // 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(); var pInit = new PolicyTree(TpmAlgId.Sha256); var p = new PolicyTree(TpmAlgId.Sha256); // // In the first part of this sample we establish keys, NV-slots, // etc. that will be used in the policy. // // // create a new RSA software signing key. We will use this for both // TpmPolicySigned AND TpmPolicyAuthorize. // var signKeyPublicTemplate = new TpmPublic(TpmAlgId.Sha256, ObjectAttr.Sign | ObjectAttr.Restricted | ObjectAttr.FixedTPM, new byte[0], new RsaParms(new SymDefObject(), new SchemeRsassa(TpmAlgId.Sha256), 2048, 0), new Tpm2bPublicKeyRsa()); _publicSigningKey = new AsymCryptoSystem(signKeyPublicTemplate); // // Get an authorization ticket for TpmPolicyAuthorize. We will authorize // a policy-digest consisting of policyPhysPresense. // var tempPolicy = new PolicyTree(TpmAlgId.Sha256); tempPolicy.Create( new PolicyAce[] { new TpmPolicyPhysicalPresence(), "leaf" }); TpmHash initPolicyHash = tempPolicy.GetPolicyDigest(); var policyAuthRef = new byte[0]; byte[] dataToSign = Globs.Concatenate(initPolicyHash.HashData, policyAuthRef); byte[] aHash = CryptoLib.HashData(TpmAlgId.Sha256, Globs.Concatenate(initPolicyHash.HashData, policyAuthRef)); // // Sign the simple policy just containing PolicyPhysPres so that // we can change it to a new value with PolicyAuthorize. // ISignatureUnion policyAuthSig = _publicSigningKey.Sign(dataToSign); // // Get a ticket verifying the signature. // TpmHandle verifierHandle = tpm.LoadExternal(null, _publicSigningKey.GetPublicParms(), TpmHandle.RhOwner); tpm.VerifySignature(verifierHandle, aHash, policyAuthSig); tpm.FlushContext(verifierHandle); // // Get the value of PCR[1] // var pcrs = new uint[] { 1 }; var sel = new PcrSelection(TpmAlgId.Sha, pcrs); PcrSelection[] selOut; Tpm2bDigest[] pcrValues; tpm.PcrRead(new[] { sel }, out selOut, out pcrValues); // // Save the current PCR values in a convenient data structure // var expectedPcrVals = new PcrValueCollection(selOut, pcrValues); // // Set up an NV slot // TpmHandle nvHandle = TpmHandle.NV(3001); // // Clean anything that might have been there before // tpm[ownerAuth]._AllowErrors().NvUndefineSpace(TpmHandle.RhOwner, nvHandle); AuthValue nvAuth = AuthValue.FromRandom(8); tpm[ownerAuth].NvDefineSpace(TpmHandle.RhOwner, nvAuth, new NvPublic(nvHandle, TpmAlgId.Sha1, NvAttr.TpmaNvAuthread | NvAttr.TpmaNvAuthwrite, new byte[0], 32)); // // write some data // var nvData = new byte[] { 0, 1, 2, 3, 4, 5, 6, 7 }; tpm[nvAuth].NvWrite(nvHandle, nvHandle, nvData, 0); byte[] nvName; tpm.NvReadPublic(nvHandle, out nvName); // // Install evaluation callback // Note: generally the callback will check that the parameters are // actions that it is willing to authorize. Those checks are omitted here. // p.SetNvCallback((PolicyTree policyTree, TpmPolicyNV ace, out SessionBase authorizingSession, out TpmHandle authorizedEntityHandle, out TpmHandle nvHandleIs) => { authorizedEntityHandle = nvHandle; nvHandleIs = nvHandle; authorizingSession = nvAuth; }); // // counter-timer: The policy will check that the reset-count // is the current value. // int start, end; TimeInfo now = tpm.ReadClock(); Marshaller.GetFragmentInfo(now, "resetCount", out start, out end); byte[] operandB = Marshaller.GetTpmRepresentation(now.clockInfo.resetCount); // // Get a cpHash for the command we want to execute // var cpHash = new TpmHash(TpmAlgId.Sha256); tpm._GetCpHash(cpHash).HierarchyChangeAuth(TpmHandle.RhOwner, ownerAuth); p.SetSignerCallback(SignerCallback); // // PolicySecret tests knowledge of ownerAuth. Note that the callback // will generally check that it is prepared to authorize what it is // being asked to authorize. Those checks are omitted here (we just // provide a PWAP session containing ownerAuth. // p.SetPolicySecretCallback((PolicyTree policyTree, TpmPolicySecret ace, out SessionBase authorizingSession, out TpmHandle authorizedEntityHandle, out bool flushAuthEntity) => { authorizingSession = ownerAuth; authorizedEntityHandle = TpmHandle.RhOwner; flushAuthEntity = false; }); // // If the policy contains a TpmPolicyAction then print out the // action string on the console. // p.SetPolicyActionCallback((PolicyTree policy, TpmPolicyAction ace) => Console.WriteLine(ace.Action)); var policyRef = new byte[] { 1, 2, 3, 4 }; // // Ticket expiration times have to be negative. // Positive expiration times do not generate a ticket. // _expectedExpirationTime = -60; // // A normalized policy is an array of policy-chains written as // arrays. Here "most" of the policy-ACEs are in the first chain, but some // ACEs cannot co-exist, and some need a ticket from a prior evaluation. // pInit.CreateNormalizedPolicy( new[] { new PolicyAce[] { new TpmPolicySigned(_publicSigningKey.GetPublicParms().GetName(), // Newly created PubKey true, // Nonce in signed data _expectedExpirationTime, // expirationTime new byte[0], // cpHash policyRef) // policyRef {NodeId = "Signing Key 1"}, // Distinguishing name // // Include owner-auth // new TpmPolicySecret(TpmHandle.RhOwner.GetName(), true, new byte[0], new byte[] {1, 2, 3}, 0), // // Include PCR-values read earlier // new TpmPolicyPcr(expectedPcrVals), // // Command must be issued at locality two // new TpmPolicyLocality(LocalityAttr.TpmLocTwo), // // NV-data we set earlier must be present // new TpmPolicyNV(nvName, nvData, 0, Eo.Eq), // // This is a "dummy ACE" that is not executed on the TPM but // a callback will be invoked at when the policy is executed. // One use case for this is to increment a counter between two // PolicyNV counter-checks. // new TpmPolicyAction("Output of TpmPolicyAction when executed."), // // Boot-count must be what we read earlier // new TpmPolicyCounterTimer(operandB, (ushort) start, Eo.Eq), // // Only authorize HierarchyChangeAuth // new TpmPolicyCommand(TpmCc.HierarchyChangeAuth), // // Include password // new TpmPolicyPassword(), // // Authorize a change from PolicyPP (last ACE below) // new TpmPolicyAuthorize(initPolicyHash.HashData, policyAuthRef, _publicSigningKey.GetPublicParms(), TpmAlgId.Sha256, policyAuthSig), // // Demand that the command be executed with PP asserted // new TpmPolicyPhysicalPresence(), // // Name for this branch // "branch_1" }, new PolicyAce[] { // // Bind to command/parameters // new TpmPolicyCpHash(cpHash), // // Name for this branch // "branch_2" }, new PolicyAce[] { new TpmPolicyTicket(_publicSigningKey.GetPublicParms(), policyRef, TpmSt.AuthSigned) // // Distinguishing name for this node // {NodeId = "PolicyTicket"}, // // Name for this branch // "branch_3" }, // // TODO: These ACEs are not evaluated yet in this sample // new PolicyAce[] { new TpmPolicyNameHash(), new TpmPolicyCpHash(cpHash), new TpmPolicyDuplicationSelect(new byte[0], new byte[0], true), new TpmPolicyAuthValue(), // Include entity authValue in HMAC new TpmPolicyNvWritten(), "branch_4" } } ); TpmHash policyHash = pInit.GetPolicyDigest(); // // Check that we can serialize and deserialize the policy // const string fileName = @".\test1.xml"; pInit.SerializeToFile("Sample Policy",PolicySerializationFormat.Xml, fileName); p.DeserializeFromFile(PolicySerializationFormat.Xml, fileName); // // And check that the policy hash is the same // TpmHash deserializedHash = p.GetPolicyDigest(); if (policyHash != deserializedHash) { throw new Exception("Serialization error"); } // // Execute the policy on the TPM. Start with "branch_1". // AuthSession s0 = tpm.StartAuthSessionEx(TpmSe.Policy, TpmAlgId.Sha256); s0.RunPolicy(tpm, p, "branch_1"); // // Check that the executed policy has the correct digest // byte[] actualPolicyDigest = tpm.PolicyGetDigest(s0.Handle); if (policyHash != actualPolicyDigest) { throw new Exception("Policy Evaluation error"); } // // Set a command to use the policy // tpm[ownerAuth].SetPrimaryPolicy(TpmHandle.RhOwner, policyHash.HashData, TpmAlgId.Sha256); // // And then execute the command // tpm._AssertPhysicalPresence(true); tpm._SetLocality(LocalityAttr.TpmLocTwo); tpm[s0].HierarchyChangeAuth(TpmHandle.RhOwner, ownerAuth); tpm._SetLocality(LocalityAttr.TpmLocZero); tpm._AssertPhysicalPresence(false); tpm.FlushContext(s0.Handle); // // Next, "branch_2". // s0 = tpm.StartAuthSessionEx(TpmSe.Policy, TpmAlgId.Sha256); s0.RunPolicy(tpm, p, "branch_2"); tpm[s0].HierarchyChangeAuth(TpmHandle.RhOwner, ownerAuth); tpm.FlushContext(s0.Handle); // // Now "branch_3" - ticket. Copy parms out of the ticket/ACE returned // from TpmPolicySinged above. // var sigAce = p.GetAce<TpmPolicySigned>("Signing Key 1"); TkAuth signedTicket = p.GetTicket("Signing Key 1"); var tickAce = p.GetAce<TpmPolicyTicket>("PolicyTicket"); tickAce.CpHash = sigAce.CpHash; tickAce.PolicyRef = sigAce.PolicyRef; tickAce.ExpirationTime = sigAce.GetTimeout(); tickAce.SetTicket(signedTicket); s0 = tpm.StartAuthSessionEx(TpmSe.Policy, TpmAlgId.Sha256); s0.RunPolicy(tpm, p, "branch_3"); tpm[s0].HierarchyChangeAuth(TpmHandle.RhOwner, ownerAuth); tpm.FlushContext(s0.Handle); Console.WriteLine("Finished SamplePolicySerializationAndCallbacks."); }
/// <summary> /// This sample demonstrates how policies can be created in a standard /// form and then shared between hosts. /// </summary> static void PolicySerialization() { Console.WriteLine("Policy serialization and de-serialization sample:"); // // Create a policy session with two branches // var policy0 = new PolicyTree(TpmAlgId.Sha256); policy0.CreateNormalizedPolicy(new[] { new PolicyAce[] { new TpmPolicyPassword(), new TpmPolicyLocality(LocalityAttr.TpmLocZero), new TpmPolicyChainId("branch_1") }, new PolicyAce[] { new TpmPolicyPassword(), new TpmPolicyCommand(TpmCc.ChangeEPS), "branch_2" } }); // // And save it to disk as XML // const string fileName = "PolicySerialization.xml"; policy0.SerializeToFile("Test Policy", PolicySerializationFormat.Xml, fileName); // // Now recover it into a new session // var policy1 = new PolicyTree(TpmAlgId.Sha256); policy1.DeserializeFromFile(PolicySerializationFormat.Xml, fileName); // // And check that the two policies are the same // if (policy0.GetPolicyDigest() != policy1.GetPolicyDigest()) { throw new Exception("Policy library error"); } Console.WriteLine("Serialized policy to {0}.", fileName); // // And now do the same, but serialized to JSON // const string fileNameJ = "PolicySerialization.json"; policy0.SerializeToFile("Test Policy", PolicySerializationFormat.Json, fileNameJ); // // Now recover it into a new session // var policy1J = new PolicyTree(TpmAlgId.Sha256); policy1J.DeserializeFromFile(PolicySerializationFormat.Json, fileNameJ); // // And check that the two policies are the same // if (policy0.GetPolicyDigest() != policy1J.GetPolicyDigest()) { throw new Exception("Policy library error"); } Console.WriteLine("Serialized policy to {0}.", fileNameJ); }