// Creates a NoteEncryption private key
public static UInt256 generate_privkey(UInt252 a_sk)
{
UInt256 sk = PRFClass.PRF_addr_sk_enc(a_sk);
clamp_curve25519(sk.ToArray());
return(sk);
}
public static UInt256 PRF_addr(UInt252 a_sk, byte t)
{
UInt256 temp = new UInt256();
byte[] byTemp = temp.ToArray();
byTemp[0] = t;
UInt256 y = new UInt256(byTemp);
return(PRF(true, true, false, false, a_sk, y));
}
public static UInt256 PRF_pk(UInt252 a_sk, Fixed8 i0, UInt256 h_sig)
{
if ((i0.GetData() != 0) && (i0.GetData() != 1))
{
throw new FormatException("i0 is not correct");
}
if (i0.GetData() == 0)
{
return(PRF(false, false, false, false, a_sk, h_sig));
}
else
{
return(PRF(false, true, false, false, a_sk, h_sig));
}
}
public static UInt256 PRF(bool a, bool b, bool c, bool d, UInt252 x, UInt256 y)
{
UInt256 res;
byte[] blob = new byte[64];
x.ToArray().ToHexString().HexToBytesInverse().CopyTo(blob, 0);
y.ToArray().ToHexString().HexToBytesInverse().CopyTo(blob, 32);
blob[0] &= 0x0F;
blob[0] |= (byte)((a ? 1 << 7 : 0) | (b ? 1 << 6 : 0) | (c ? 1 << 5 : 0) | (d ? 1 << 4 : 0));
using (SHA256 hasher = SHA256.Create())
{
byte[] hashValue;
hashValue = hasher.ComputeHash(blob);
res = new UInt256(hashValue);
}
return(res);
}
public Note note(UInt252 phi, UInt256 r, Fixed8 i, UInt256 h_sig)
{
UInt256 rho = PRFClass.PRF_rho(phi, i, h_sig);
return(new Note(addr.a_pk, value, rho, r, AssetID));
}
public static UInt256 PRF_addr_sk_enc(UInt252 a_sk)
{
return(PRF_addr(a_sk, 1));
}
public static UInt256 PRF_addr_a_pk(UInt252 a_sk)
{
return(PRF_addr(a_sk, 0));
}
public static UInt256 PRF_nf(UInt252 a_sk, UInt256 rho)
{
return(PRF(true, true, true, false, a_sk, rho));
}
public virtual QrsProof prove(
List <JSInput> inputs,
List <JSOutput> outputs,
List <Note> out_notes,
List <byte[]> out_ciphertexts,
UInt256 out_ephemeralKey,
UInt256 pubKeyHash,
UInt256 out_randomSeed,
List <UInt256> out_macs,
List <UInt256> out_nullifiers,
List <UInt256> out_commitments,
Fixed8 vpub_old,
Fixed8 vpub_new,
UInt256 rt,
bool computeProof = true,
// For paymentdisclosure, we need to retrieve the esk.
// Reference as non-const parameter with default value leads to compile error.
// So use pointer for simplicity.
UInt256 out_esk = null
)
{
Fixed8 lhs_value = vpub_old;
Fixed8 rhs_value = vpub_new;
for (int i = 0; i < inputs.Count; i++)
{
lhs_value += inputs[i].note.value;
out_nullifiers.Add(inputs[i].Nullifier());
}
out_randomSeed = UInt256.Random();
UInt256 h_sig = QrsJoinSplit.h_sig(out_randomSeed, out_nullifiers, pubKeyHash);
UInt252 phi = new UInt252(UInt256.Random());
for (int i = 0; i < outputs.Count; i++)
{
rhs_value += outputs[i].value;
UInt256 r = UInt256.Random();
out_notes.Add(outputs[i].note(phi, r, new Fixed8(i), h_sig));
}
if (lhs_value != rhs_value)
{
throw new ArgumentException();
}
for (int i = 0; i < outputs.Count; i++)
{
out_commitments.Add(out_notes[i].CM());
}
{
NoteEncryption encryptor = new NoteEncryption(h_sig);
for (int i = 0; i < outputs.Count; i++)
{
NotePlaintext pt = new NotePlaintext(out_notes[i], outputs[i].memo);
out_ciphertexts.Add(pt.encrypt(encryptor, outputs[i].addr.pk_enc));
}
out_ephemeralKey = encryptor.get_epk();
out_esk = encryptor.get_esk();
}
for (int i = 0; i < inputs.Count; i++)
{
out_macs.Add(PRFClass.PRF_pk(inputs[i].key, new Fixed8(i), h_sig));
}
return(null);
}
