1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
/*
* This file is part of GNU Taler
* (C) 2020 Taler Systems S.A.
*
* GNU Taler is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation; either version 3, or (at your option) any later version.
*
* GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
* A PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with
* GNU Taler; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
*/
package net.taler.wallet.kotlin.crypto
import net.taler.wallet.kotlin.Base32Crockford
import net.taler.wallet.kotlin.CoinRecord
import net.taler.wallet.kotlin.CoinSourceType.REFRESH
import net.taler.wallet.kotlin.crypto.Signature.Companion.WALLET_COIN_RECOUP
internal class Recoup(private val crypto: Crypto) {
/**
* Request that we send to the exchange to get a payback.
*/
data class Request(
/**
* Hashed denomination public key of the coin we want to get
* paid back.
*/
val denomPubHash: String,
/**
* Signature over the coin public key by the denomination.
*/
val denomSig: String,
/**
* Coin public key of the coin we want to refund.
*/
val coinPub: String,
/**
* Blinding key that was used during withdraw,
* used to prove that we were actually withdrawing the coin.
*/
val coinBlindKeySecret: String,
/**
* Signature made by the coin, authorizing the payback.
*/
val coinSig: String,
/**
* Was the coin refreshed (and thus the recoup should go to the old coin)?
*/
val refreshed: Boolean
)
/**
* Create and sign a message to recoup a coin.
*/
fun createRequest(coin: CoinRecord): Request {
val p = Signature.PurposeBuilder(WALLET_COIN_RECOUP)
.put(Base32Crockford.decode(coin.coinPub))
.put(Base32Crockford.decode(coin.denomPubHash))
.put(Base32Crockford.decode(coin.blindingKey))
.build()
val coinSig = crypto.eddsaSign(p, Base32Crockford.decode(coin.coinPriv))
return Request(
coinBlindKeySecret = coin.blindingKey,
coinPub = coin.coinPub,
coinSig = Base32Crockford.encode(coinSig),
denomPubHash = coin.denomPubHash,
denomSig = coin.denomSig,
refreshed = coin.coinSource === REFRESH
)
}
}
|
