/// <summary>
/// De-envelope inner-wrapped duplication blob.
/// TODO: Move this to TpmPublic and make it fully general
/// </summary>
/// <param name="exportedPrivate"></param>
/// <param name="encAlg"></param>
/// <param name="encKey"></param>
/// <param name="nameAlg"></param>
/// <param name="name"></param>
/// <returns></returns>
public static Sensitive SensitiveFromDuplicateBlob(TpmPrivate exportedPrivate, SymDefObject encAlg, byte[] encKey, TpmAlgId nameAlg, byte[] name)
{
byte[] dupBlob = exportedPrivate.buffer;
byte[] sensNoLen;
using (SymmCipher c = Create(encAlg, encKey))
{
byte[] innerObject = c.Decrypt(dupBlob);
byte[] innerIntegrity, sensitive;
KDF.Split(innerObject,
16 + CryptoLib.DigestSize(nameAlg) * 8,
out innerIntegrity,
8 * (innerObject.Length - CryptoLib.DigestSize(nameAlg) - 2),
out sensitive);
byte[] expectedInnerIntegrity = Marshaller.ToTpm2B(CryptoLib.HashData(nameAlg, sensitive, name));
if (!Globs.ArraysAreEqual(expectedInnerIntegrity, innerIntegrity))
{
Globs.Throw("SensitiveFromDuplicateBlob: Bad inner integrity");
}
sensNoLen = Marshaller.Tpm2BToBuffer(sensitive);
}
var sens = Marshaller.FromTpmRepresentation <Sensitive>(sensNoLen);
return(sens);
}
