/// <summary>
/// Creates a Private area for this key so that it can be loaded into a TPM by
/// TPM2_Load() if the target TPM already has the storage key 'parent' loaded.
/// This function lets an application to create key hierarchies in software
/// that can be loaded into a TPM once the parent has been TPM2_Import'ed.
/// TPM2_Import() supports plaintext import. To get this sort of import blob,
/// set 'parent' to null.
/// </summary>
/// <param name="parent"></param>
/// <returns></returns>
public TpmPrivate GetPrivate(TssObject parent)
{
SymDefObject symDef = GetSymDef(parent.Public);
// Figure out how many bits we will need from the KDF
byte[] parentSymSeed = parent.Sensitive.seedValue;
Transform(parentSymSeed);
byte[] iv = (symDef.Mode == TpmAlgId.Ecb) ? new byte[0]
: Globs.GetRandomBytes(SymCipher.GetBlockSize(symDef));
// The encryption key is calculated with a KDF
byte[] symKey = KDF.KDFa(parent.Public.nameAlg,
parentSymSeed,
"STORAGE",
GetName(),
new byte[0],
symDef.KeyBits);
Transform(symKey);
byte[] newPrivate = KeyWrapper.CreatePrivateFromSensitive(
symDef,
symKey,
iv,
Sensitive,
Public.nameAlg,
Public.GetName(),
parent.Public.nameAlg,
parent.Sensitive.seedValue,
TransformerCallback);
Transform(newPrivate);
return(new TpmPrivate(newPrivate));
}
/// <summary>
/// Creates a Private area for this key that will be loadable on a TPM though TPM2_Load() if the target TPM already has the parent
/// storage key "parent" loaded. This function lets applications create key-hierarchies in software that can be loaded into
/// a TPM once the parent has been "TPM2_Import'ed."
/// TPM2_Import() supports plaintext import. To get this sort of import blob set intendedParent
/// to null
/// </summary>
/// <param name="intendedParent"></param>
/// <returns></returns>
public TpmPrivate GetPrivate(TssObject intendedParent)
{
SymDefObject symDef = GetSymDef(intendedParent.publicPart);
// Figure out how many bits we will need from the KDF
byte[] parentSymValue = intendedParent.sensitivePart.seedValue;
byte[] iv = Globs.GetRandomBytes(SymmCipher.GetBlockSize(symDef));
// The encryption key is calculated with a KDF
byte[] symKey = KDF.KDFa(intendedParent.publicPart.nameAlg,
parentSymValue,
"STORAGE",
GetName(),
new byte[0],
symDef.KeyBits);
byte[] newPrivate = KeyWrapper.CreatePrivateFromSensitive(symDef,
symKey,
iv,
sensitivePart,
publicPart.nameAlg,
publicPart.GetName(),
intendedParent.publicPart.nameAlg,
intendedParent.sensitivePart.seedValue);
return(new TpmPrivate(newPrivate));
}
