} // SimpleDuplicateImportRsaSample
TssObject ImportExternalRsaKey(Tpm2 tpm, TpmHandle hParent,
int keySizeInBits, IAsymSchemeUnion scheme,
byte[] publicPart, byte[] privatePart,
ObjectAttr keyAttrs,
byte[] authVal = null, byte[] policyDigest = null)
{
TpmAlgId sigHashAlg = TpmHelper.GetSchemeHash(scheme),
nameAlg = sigHashAlg;
// TPM signing key template with the actual public key bits
var inPub = new TpmPublic(nameAlg,
keyAttrs,
policyDigest,
new RsaParms(new SymDefObject(), scheme as IAsymSchemeUnion,
(ushort)keySizeInBits, 0),
new Tpm2bPublicKeyRsa(publicPart));
// Wrap the key in a TSS helper class
TssObject swKey = TssObject.Create(inPub, authVal, privatePart);
// Get a key duplication blob in TPM 2.0 compatibale format
TpmPrivate dupBlob = swKey.GetPlaintextDuplicationBlob();
// Importing a duplication blob creates a new TPM private key blob protected
// with its new parent key.
swKey.Private = tpm.Import(hParent, null, swKey.Public, dupBlob, null, new SymDefObject());
return(swKey);
} // ImportExternalRsaKey
void DuplicateImportRsaSample(Tpm2 tpm, TestContext testCtx)
{
TpmAlgId nameAlg = Substrate.Random(TpmCfg.HashAlgs);
var policy = new PolicyTree(nameAlg);
policy.SetPolicyRoot(new TpmPolicyCommand(TpmCc.Duplicate));
var inPub = new TpmPublic(nameAlg,
ObjectAttr.Sign | ObjectAttr.AdminWithPolicy | ObjectAttr.SensitiveDataOrigin,
policy.GetPolicyDigest(),
new RsaParms(new SymDefObject(),
new SchemeRsassa(Substrate.Random(TpmCfg.HashAlgs)),
Substrate.Random(TpmCfg.RsaKeySizes), 0),
new Tpm2bPublicKeyRsa());
TpmHandle hKey = Substrate.CreateAndLoad(tpm, inPub, out TpmPublic pub);
// Duplicate
TpmPrivate priv = TpmHelper.GetPlaintextPrivate(tpm, hKey, policy);
tpm.FlushContext(hKey);
// Import
TpmPrivate privImp = tpm.Import(Substrate.LoadRsaPrimary(tpm), null, pub, priv, null, new SymDefObject());
} // SimpleDuplicateImportRsaSample
internal static TpmHandle CreateEncryptionDecryptionKey(Tpm2 tpm, TpmHandle parent)
{
var sensCreate = new SensitiveCreate(null, null);
var sym = new SymDefObject(TpmAlgId.Aes, 128, TpmAlgId.Cfb);
var pub = new TpmPublic(TpmAlgId.Sha256,
ObjectAttr.Decrypt | ObjectAttr.UserWithAuth,
null,
sym,
new Tpm2bDigestSymcipher());
TssObject swKey = TssObject.Create(pub);
var innerWrapKey = sym == null ? null : SymCipher.Create(sym);
byte[] name, qname;
TpmPublic pubParent = tpm.ReadPublic(parent, out name, out qname);
byte[] encSecret;
TpmPrivate dupBlob = swKey.GetDuplicationBlob(pubParent, innerWrapKey, out encSecret);
TpmPrivate privImp = tpm.Import(parent, innerWrapKey, swKey.Public, dupBlob,
encSecret, sym ?? new SymDefObject());
TpmHandle hKey = tpm.Load(parent, privImp, swKey.Public)
.SetAuth(swKey.Sensitive.authValue);
return(hKey);
}
/// <summary>
/// Activates an identity key within the TPM device.
/// </summary>
/// <param name="encryptedKey">The encrypted identity key.</param>
public override void ActivateIdentityKey(byte[] encryptedKey)
{
if (Logging.IsEnabled)
{
Logging.Enter(this, $"{encryptedKey}", nameof(ActivateIdentityKey));
}
Destroy();
// Take the pieces out of the container
var m = new Marshaller(encryptedKey, DataRepresentation.Tpm);
Tpm2bIdObject cred2b = m.Get <Tpm2bIdObject>();
byte[] encryptedSecret = new byte[m.Get <ushort>()];
encryptedSecret = m.GetArray <byte>(encryptedSecret.Length, "encryptedSecret");
TpmPrivate dupBlob = m.Get <TpmPrivate>();
byte[] encWrapKey = new byte[m.Get <ushort>()];
encWrapKey = m.GetArray <byte>(encWrapKey.Length, "encWrapKey");
UInt16 pubSize = m.Get <UInt16>();
_idKeyPub = m.Get <TpmPublic>();
byte[] cipherText = new byte[m.Get <ushort>()];
cipherText = m.GetArray <byte>(cipherText.Length, "uriInfo");
// Setup the authorization session for the EK
var policyNode = new TpmPolicySecret(TpmHandle.RhEndorsement, false, 0, Array.Empty <byte>(), Array.Empty <byte>());
var policy = new PolicyTree(_ekPub.nameAlg);
policy.SetPolicyRoot(policyNode);
AuthSession ekSession = _tpm2.StartAuthSessionEx(TpmSe.Policy, _ekPub.nameAlg);
ekSession.RunPolicy(_tpm2, policy);
// Perform the activation
ekSession.Attrs &= ~SessionAttr.ContinueSession;
_activationSecret = _tpm2[Array.Empty <byte>(), ekSession].ActivateCredential(
new TpmHandle(TPM_20_SRK_HANDLE),
new TpmHandle(TPM_20_EK_HANDLE),
cred2b.credential,
encryptedSecret);
TpmPrivate importedKeyBlob = _tpm2.Import(
new TpmHandle(TPM_20_SRK_HANDLE),
_activationSecret,
_idKeyPub,
dupBlob,
encWrapKey,
new SymDefObject(TpmAlgId.Aes, 128, TpmAlgId.Cfb));
_idKeyHandle = _tpm2.Load(new TpmHandle(TPM_20_SRK_HANDLE), importedKeyBlob, _idKeyPub);
// Persist the key in NV
TpmHandle hmacKeyHandle = new TpmHandle(AIOTH_PERSISTED_KEY_HANDLE);
_tpm2.EvictControl(new TpmHandle(TpmRh.Owner), _idKeyHandle, hmacKeyHandle);
// Unload the transient copy from the TPM
_tpm2.FlushContext(_idKeyHandle);
_idKeyHandle = hmacKeyHandle;
if (Logging.IsEnabled)
{
Logging.Exit(this, $"{encryptedKey}", nameof(ActivateIdentityKey));
}
}
/// <summary>
/// Activates a symmetric identity within the Hardware Security Module.
/// </summary>
/// <param name="activation">The authentication challenge key supplied by the service.</param>
public override void ActivateSymmetricIdentity(byte[] activation)
{
Destroy();
// Take the pieces out of the container
var m = new Marshaller(activation, DataRepresentation.Tpm);
byte[] credentialBlob = new byte[m.Get <ushort>()];
credentialBlob = m.GetArray <byte>(credentialBlob.Length, "credentialBlob");
byte[] encryptedSecret = new byte[m.Get <ushort>()];
encryptedSecret = m.GetArray <byte>(encryptedSecret.Length, "encryptedSecret");
TpmPrivate dupBlob = m.Get <TpmPrivate>();
byte[] encWrapKey = new byte[m.Get <ushort>()];
encWrapKey = m.GetArray <byte>(encryptedSecret.Length, "encWrapKey");
UInt16 pubSize = m.Get <UInt16>();
_idKeyPub = m.Get <TpmPublic>();
byte[] cipherText = new byte[m.Get <ushort>()];
cipherText = m.GetArray <byte>(cipherText.Length, "uriInfo");
// Setup the authorization session for the EK
var policyNode = new TpmPolicySecret(
TpmHandle.RhEndorsement, _ekAuth ?? Array.Empty <byte>(),
new AuthValue(),
false,
0,
Array.Empty <byte>(),
Array.Empty <byte>());
var policy = new PolicyTree(_ekPub.nameAlg);
policy.SetPolicyRoot(policyNode);
AuthSession ekSession = _tpm2.StartAuthSessionEx(TpmSe.Policy, _ekPub.nameAlg);
ekSession.RunPolicy(_tpm2, policy);
// Perform the activation
ekSession.Attrs &= ~SessionAttr.ContinueSession;
_activationSecret = _tpm2[Array.Empty <byte>(), ekSession].ActivateCredential(
new TpmHandle(TPM_20_SRK_HANDLE),
new TpmHandle(TPM_20_EK_HANDLE),
credentialBlob,
encryptedSecret);
TpmPrivate importedKeyBlob = _tpm2.Import(
new TpmHandle(TPM_20_SRK_HANDLE),
_activationSecret,
_idKeyPub,
dupBlob,
encWrapKey,
new SymDefObject(TpmAlgId.Aes, 128, TpmAlgId.Cfb));
_idKeyHandle = _tpm2.Load(new TpmHandle(TPM_20_SRK_HANDLE), importedKeyBlob, _idKeyPub);
// Persist the key in NV
TpmHandle hmacKeyHandle = new TpmHandle(AIOTH_PERSISTED_KEY_HANDLE);
_tpm2.EvictControl(new TpmHandle(TpmRh.Owner), _idKeyHandle, hmacKeyHandle);
// Unload the transient copy from the TPM
_tpm2.FlushContext(_idKeyHandle);
_idKeyHandle = hmacKeyHandle;
// Unwrap the URI
byte[] clearText = SymmCipher.Decrypt(
new SymDefObject(TpmAlgId.Aes, 128, TpmAlgId.Cfb),
_activationSecret,
new byte[16],
cipherText);
UnicodeEncoding unicode = new UnicodeEncoding();
string uriData = unicode.GetString(clearText);
int idx = uriData.IndexOf('/');
if (idx > 0)
{
string hostName = uriData.Substring(0, idx);
string deviceId = uriData.Substring(idx + 1);
// Persist the URI
ProvisionUri(hostName, deviceId);
}
}
/// <summary>
/// Performs the following operations:
/// - Generates in software (using TSS.net helpers) a key with the given template,
/// - Creates TPM-compatible dupliction blob for the given TPM based parent key,
/// - Import the duplication blob into TPM
/// - Loads the imported key into the TPM
/// - Makes sure that the imported key works.
/// </summary>
/// <param name="tpm">TPM instance to use</param>
/// <param name="keyPub">Template for the software generated key.</param>
/// <param name="hParent">Intended TPM based parent key for the software generated key.</param>
/// <param name="innerSymDef">Specification of the optional inner wrapper for the duplication blob.</param>
static void GenerateAndImport(Tpm2 tpm, TpmPublic keyPub, TpmHandle hParent,
SymDefObject innerSymDef = null)
{
//
// Create a software key with the given template
//
// Generate a random auth value for the key to be created (though we could
// use an empty buffer, too).
var keyAuth = AuthValue.FromRandom(CryptoLib.DigestSize(keyPub.nameAlg));
// Generate the key
TssObject swKey = TssObject.Create(keyPub, keyAuth);
//
// Create duplication blob for the new key with the SRK as the new parent
//
// Create a symmetric software key if an inner wrapper is requested.
var innerWrapKey = innerSymDef == null ? null : SymCipher.Create(innerSymDef);
// Retrieve the public area of the intended parent key from the TPM
// We do not need the name (and qualified name) of the key here, but
// the TPM command returns them anyway.
// NOTE - Alternatively we could get the public area from the overloaded
// form of the CreateRsaPrimaryStorageKey() helper used to create the parent
// key, as all TPM key creation commands (TPM2_CreatePrimary(), TPM2_Create()
// and TPM2_CreateLoaded()) return it.
byte[] name, qname;
TpmPublic pubParent = tpm.ReadPublic(hParent, out name, out qname);
byte[] encSecret;
TpmPrivate dupBlob = swKey.GetDuplicationBlob(pubParent, innerWrapKey, out encSecret);
// Import the duplication blob into the TPM
TpmPrivate privImp = tpm.Import(hParent, innerWrapKey, swKey.Public, dupBlob,
encSecret, innerSymDef ?? new SymDefObject());
// Load the imported key ...
TpmHandle hKey = tpm.Load(hParent, privImp, swKey.Public)
.SetAuth(swKey.Sensitive.authValue);
// ... and validate that it works
byte[] message = Globs.GetRandomBytes(32);
if (keyPub.objectAttributes.HasFlag(ObjectAttr.Decrypt))
{
// Encrypt something
if (keyPub.type == TpmAlgId.Symcipher)
{
// Only need software symcypher here to query IV size.
// Normally, when you use a fixed algorithm, you can hardcode it.
var swSym = SymCipher.Create(keyPub.parameters as SymDefObject);
byte[] ivIn = Globs.GetRandomBytes(swSym.IVSize),
ivOut = null;
byte[] cipher = swKey.Encrypt(message, ref ivIn, out ivOut);
// Not all TPMs implement TPM2_EncryptDecrypt() command
tpm._ExpectResponses(TpmRc.Success, TpmRc.TbsCommandBlocked);
byte[] decrypted = tpm.EncryptDecrypt(hKey, 1, TpmAlgId.Null, ivIn,
cipher, out ivOut);
if (tpm._LastCommandSucceeded())
{
bool decOk = Globs.ArraysAreEqual(message, decrypted);
Console.WriteLine("Imported symmetric key validation {0}",
decOk ? "SUCCEEDED" : "FAILED");
}
}
}
else
{
// Sign something (works for both asymmetric and MAC keys)
string keyType = keyPub.type == TpmAlgId.Rsa ? "RSA"
: keyPub.type == TpmAlgId.Keyedhash ? "HMAC"
: "UNKNOWN"; // Should not happen in this sample
TpmAlgId sigHashAlg = GetSchemeHash(keyPub);
TpmHash toSign = TpmHash.FromData(sigHashAlg, message);
var proofx = new TkHashcheck(TpmRh.Null, null);
ISignatureUnion sig = tpm.Sign(hKey, toSign, null, proofx);
bool sigOk = swKey.VerifySignatureOverHash(toSign, sig);
Console.WriteLine("Imported {0} key validation {1}", keyType,
sigOk ? "SUCCEEDED" : "FAILED");
}
// Free TPM resources taken by the loaded imported key
tpm.FlushContext(hKey);
} // GenerateAndImport
