[Trustedjava-support] Binding through public part of binding key

[Shakir U. S. <sha...@nu...>]

I'm trying to bind some data using the public part of a binding key. I've
exported the public part through:

    byte blob[] = null;
    try {
        File f = new File(BINDKEY_FILENAME);
        blob = new byte[(int) f.length()];
        FileInputStream fi = new FileInputStream(f);
        fi.read(blob);
    } catch (Exception e) {
        e.printStackTrace();
    }

    TcBlobData srkSecret = TcBlobData
            .newByteArray(TcTssConstants.TSS_WELL_KNOWN_SECRET);
    long srkSecretMode = TcTssConstants.TSS_SECRET_MODE_SHA1;

    TcIRsaKey srk = context.loadKeyByUuidFromSystem(TcUuidFactory
            .getInstance().getUuidSRK());

    TcIPolicy srkPolicy = srk.getUsagePolicyObject();
    srkPolicy.setSecret(srkSecretMode, srkSecret);
    srkPolicy.assignToObject(srk);

    // create a TcBlobData using
    TcBlobData keyBlob = TcBlobData.newByteArray(blob);

    // load the key using this blob
    TcIRsaKey identityKey = context.loadKeyByBlob(srk, keyBlob);

    TcIRsaKey pubBindKey = identityKey;
    TcBlobData pubBindKeyBlob = pubBindKey.getAttribData(
            TcTssConstants.TSS_TSPATTRIB_KEY_BLOB,
            TcTssConstants.TSS_TSPATTRIB_KEYBLOB_PUBLIC_KEY);

    // write this pubBindKeyBlob to a file and send it to the challenger
    File f = new File(BINDKEY_PUB_FILENAME);
    byte[] pubKeyBytes = pubBindKeyBlob.asByteArray();
    System.out.println(pubKeyBytes);
    FileOutputStream fo = new FileOutputStream(f);

    fo.write(pubKeyBytes);
    fo.close();


The encryption algorithm is the following:


    public static byte[] encrypt(byte[] text, RSAPublicKey key)
            throws Exception {

        byte[] cipherText = null;
        Cipher cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, key);
        cipherText = cipher.doFinal(text);
        return cipherText;
    }

    public static void main(String[] argv) {
        final String pubBindKeyFilename = "bac_bind_pub.key";
        String fileforEncryption = "inputFileforEncryption";

        // first get the pubBindKeyBlob from file (received from the target
earlier)
        byte pubBindKey[] = null;
        byte bytefileEncryption[] = null;
        byte byteDataEncrypted[] = null;

        File f = new File(pubBindKeyFilename);
        pubBindKey = new byte[(int) f.length()];
        FileInputStream fi = new FileInputStream(f);
        fi.read(pubBindKey);
        TcBlobData pubBindKeyBlob = TcBlobData.newByteArray(pubBindKey);
        TcTpmPubkey pubBindKeyStruct = new TcTpmPubkey(pubBindKeyBlob);
        RSAPublicKey rsaPub = TcCrypto.pubTpmKeyToJava(pubBindKeyStruct);

        File ftemp = new File(fileforEncryption);
        bytefileEncryption = new byte[(int) ftemp.length()];
        FileInputStream fitemp = new FileInputStream(ftemp);
        fitemp.read(bytefileEncryption);

        byteDataEncrypted = encrypt(bytefileEncryption, rsaPub);
        String outFilename = "outputEncRsaFile";

        File f2 = new File(outFilename);
        FileOutputStream fo = new FileOutputStream(f2);
        fo.write(byteDataEncrypted);
        fo.close();


I'm using jTpmTools to decrypt the data using the binding key. Here's the
command for the decryption using jTpmTools:

    unbind -i /path/to/outputEncRsaFile -o /path/to/outputdecEncRsaFile -u
00000001-0002-0003-0405-9296a5ae537a

The UUID is of the same binding key that I've exported. I'm getting the
following exception though. I'm not sure what I'm doing wrong.

    00:55:30:935 [INFO] Unbind::execute (123):    Using default
TSS_WELL_KNOWN_SECRET as key secret
    00:55:31:078 [INFO] TcTcsEventMgrMem::<init> (44):    Using "in memory"
event log.
    iaik.tc.tss.api.exceptions.tcs.TcTpmException:

    TSS Error:
    error layer:                0x00 (TPM)
    error code (without layer): 0x21
    error code (full):          0x21
    error message: The decryption process did not complete.

    at
iaik.tc.tss.impl.java.tcs.pbg.TcTpmCmdCommon.handleRetCode(TcTpmCmdCommon.java:73)
    at
iaik.tc.tss.impl.java.tcs.pbg.TcTpmCmdStorage.TpmUnBind(TcTpmCmdStorage.java:244)
    at iaik.tc.tss.impl.java.tcs.tcsi.TcTcsi.TcsipUnBind(TcTcsi.java:1638)
    at
iaik.tc.tss.impl.java.tsp.tcsbinding.local.TcTcsBindingLocal.TcsipUnBind(TcTcsBindingLocal.java:442)
    at
iaik.tc.tss.impl.java.tsp.internal.TcTspInternal.TspUnBind_Internal(TcTspInternal.java:1766)
    at iaik.tc.tss.impl.java.tsp.TcEncData.unbind(TcEncData.java:255)
    at iaik.tc.apps.jtt.data.Unbind.execute(Unbind.java:171)
    at iaik.tc.utils.cmdline.SubCommand.run(SubCommand.java:69)
    at
iaik.tc.utils.cmdline.SubCommandParser.parse(SubCommandParser.java:41)
    at iaik.tc.apps.JTpmTools.main(JTpmTools.java:224)

    00:55:31:561 [ERROR] JTpmTools::main (235):    application exits with
error:

    TSS Error:
    error layer:                0x00 (TPM)
    error code (without layer): 0x21
    error code (full):          0x21
    error message: The decryption process did not complete.


Any help would be greatly appreciated.