-
Notifications
You must be signed in to change notification settings - Fork 222
/
fin_plan.rs
230 lines (200 loc) · 8.55 KB
/
fin_plan.rs
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
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
//! The `fin_plan` module provides a domain-specific language for payment plans. Users create FinPlan objects that
//! are given to an interpreter. The interpreter listens for `Witness` transactions,
//! which it uses to reduce the payment plan. When the fin_plan is reduced to a
//! `Payment`, the payment is executed.
use chrono::prelude::*;
use trx_out::{Payment, Witness};
use xpz_program_interface::pubkey::Pubkey;
use std::mem;
/// A data type representing a `Witness` that the payment plan is waiting on.
#[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
pub enum Condition {
/// Wait for a `Timestamp` `Witness` at or after the given `DateTime`.
Timestamp(DateTime<Utc>, Pubkey),
/// Wait for a `Signature` `Witness` from `Pubkey`.
Signature(Pubkey),
}
impl Condition {
/// Return true if the given Witness satisfies this Condition.
pub fn is_satisfied(&self, witness: &Witness, from: &Pubkey) -> bool {
match (self, witness) {
(Condition::Signature(pubkey), Witness::Signature) => pubkey == from,
(Condition::Timestamp(dt, pubkey), Witness::Timestamp(last_time)) => {
pubkey == from && dt <= last_time
}
_ => false,
}
}
}
/// A data type representing a payment plan.
#[repr(C)]
#[derive(Serialize, Deserialize, Debug, PartialEq, Eq, Clone)]
pub enum FinPlan {
/// Make a payment.
Pay(Payment),
/// Make a payment after some condition.
After(Condition, Payment),
/// Either make a payment after one condition or a different payment after another
/// condition, which ever condition is satisfied first.
Or((Condition, Payment), (Condition, Payment)),
/// Make a payment after both of two conditions are satisfied
And(Condition, Condition, Payment),
}
impl FinPlan {
/// Create the simplest fin_plan - one that pays `tokens` to Pubkey.
pub fn new_payment(tokens: i64, to: Pubkey) -> Self {
FinPlan::Pay(Payment { tokens, to })
}
/// Create a fin_plan that pays `tokens` to `to` after being witnessed by `from`.
pub fn new_authorized_payment(from: Pubkey, tokens: i64, to: Pubkey) -> Self {
FinPlan::After(Condition::Signature(from), Payment { tokens, to })
}
/// Create a fin_plan that pays tokens` to `to` after being witnessed by 2x `from`s
pub fn new_2_2_multisig_payment(from0: Pubkey, from1: Pubkey, tokens: i64, to: Pubkey) -> Self {
FinPlan::And(
Condition::Signature(from0),
Condition::Signature(from1),
Payment { tokens, to },
)
}
/// Create a fin_plan that pays `tokens` to `to` after the given DateTime.
pub fn new_future_payment(dt: DateTime<Utc>, from: Pubkey, tokens: i64, to: Pubkey) -> Self {
FinPlan::After(Condition::Timestamp(dt, from), Payment { tokens, to })
}
/// Create a fin_plan that pays `tokens` to `to` after the given DateTime
/// unless cancelled by `from`.
pub fn new_cancelable_future_payment(
dt: DateTime<Utc>,
from: Pubkey,
tokens: i64,
to: Pubkey,
) -> Self {
FinPlan::Or(
(Condition::Timestamp(dt, from), Payment { tokens, to }),
(Condition::Signature(from), Payment { tokens, to: from }),
)
}
/// Return Payment if the fin_plan requires no additional Witnesses.
pub fn final_payment(&self) -> Option<Payment> {
match self {
FinPlan::Pay(payment) => Some(payment.clone()),
_ => None,
}
}
/// Return true if the fin_plan spends exactly `spendable_tokens`.
pub fn verify(&self, spendable_tokens: i64) -> bool {
match self {
FinPlan::Pay(payment) | FinPlan::After(_, payment) | FinPlan::And(_, _, payment) => {
payment.tokens == spendable_tokens
}
FinPlan::Or(a, b) => a.1.tokens == spendable_tokens && b.1.tokens == spendable_tokens,
}
}
/// Apply a witness to the fin_plan to see if the fin_plan can be reduced.
/// If so, modify the fin_plan in-place.
pub fn apply_witness(&mut self, witness: &Witness, from: &Pubkey) {
let new_fin_plan = match self {
FinPlan::After(cond, payment) if cond.is_satisfied(witness, from) => {
Some(FinPlan::Pay(payment.clone()))
}
FinPlan::Or((cond, payment), _) if cond.is_satisfied(witness, from) => {
Some(FinPlan::Pay(payment.clone()))
}
FinPlan::Or(_, (cond, payment)) if cond.is_satisfied(witness, from) => {
Some(FinPlan::Pay(payment.clone()))
}
FinPlan::And(cond0, cond1, payment) => {
if cond0.is_satisfied(witness, from) {
Some(FinPlan::After(cond1.clone(), payment.clone()))
} else if cond1.is_satisfied(witness, from) {
Some(FinPlan::After(cond0.clone(), payment.clone()))
} else {
None
}
}
_ => None,
};
if let Some(fin_plan) = new_fin_plan {
mem::replace(self, fin_plan);
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use signature::{Keypair, KeypairUtil};
#[test]
fn test_signature_satisfied() {
let from = Pubkey::default();
assert!(Condition::Signature(from).is_satisfied(&Witness::Signature, &from));
}
#[test]
fn test_timestamp_satisfied() {
let dt1 = Utc.ymd(2014, 11, 14).and_hms(8, 9, 10);
let dt2 = Utc.ymd(2014, 11, 14).and_hms(10, 9, 8);
let from = Pubkey::default();
assert!(Condition::Timestamp(dt1, from).is_satisfied(&Witness::Timestamp(dt1), &from));
assert!(Condition::Timestamp(dt1, from).is_satisfied(&Witness::Timestamp(dt2), &from));
assert!(!Condition::Timestamp(dt2, from).is_satisfied(&Witness::Timestamp(dt1), &from));
}
#[test]
fn test_verify() {
let dt = Utc.ymd(2014, 11, 14).and_hms(8, 9, 10);
let from = Pubkey::default();
let to = Pubkey::default();
assert!(FinPlan::new_payment(42, to).verify(42));
assert!(FinPlan::new_authorized_payment(from, 42, to).verify(42));
assert!(FinPlan::new_future_payment(dt, from, 42, to).verify(42));
assert!(FinPlan::new_cancelable_future_payment(dt, from, 42, to).verify(42));
}
#[test]
fn test_authorized_payment() {
let from = Pubkey::default();
let to = Pubkey::default();
let mut fin_plan = FinPlan::new_authorized_payment(from, 42, to);
fin_plan.apply_witness(&Witness::Signature, &from);
assert_eq!(fin_plan, FinPlan::new_payment(42, to));
}
#[test]
fn test_future_payment() {
let dt = Utc.ymd(2014, 11, 14).and_hms(8, 9, 10);
let from = Keypair::new().pubkey();
let to = Keypair::new().pubkey();
let mut fin_plan = FinPlan::new_future_payment(dt, from, 42, to);
fin_plan.apply_witness(&Witness::Timestamp(dt), &from);
assert_eq!(fin_plan, FinPlan::new_payment(42, to));
}
#[test]
fn test_unauthorized_future_payment() {
// Ensure timestamp will only be acknowledged if it came from the
// whitelisted public key.
let dt = Utc.ymd(2014, 11, 14).and_hms(8, 9, 10);
let from = Keypair::new().pubkey();
let to = Keypair::new().pubkey();
let mut fin_plan = FinPlan::new_future_payment(dt, from, 42, to);
let orig_fin_plan = fin_plan.clone();
fin_plan.apply_witness(&Witness::Timestamp(dt), &to); // <-- Attack!
assert_eq!(fin_plan, orig_fin_plan);
}
#[test]
fn test_cancelable_future_payment() {
let dt = Utc.ymd(2014, 11, 14).and_hms(8, 9, 10);
let from = Pubkey::default();
let to = Pubkey::default();
let mut fin_plan = FinPlan::new_cancelable_future_payment(dt, from, 42, to);
fin_plan.apply_witness(&Witness::Timestamp(dt), &from);
assert_eq!(fin_plan, FinPlan::new_payment(42, to));
let mut fin_plan = FinPlan::new_cancelable_future_payment(dt, from, 42, to);
fin_plan.apply_witness(&Witness::Signature, &from);
assert_eq!(fin_plan, FinPlan::new_payment(42, from));
}
#[test]
fn test_2_2_multisig_payment() {
let from0 = Keypair::new().pubkey();
let from1 = Keypair::new().pubkey();
let to = Pubkey::default();
let mut fin_plan = FinPlan::new_2_2_multisig_payment(from0, from1, 42, to);
fin_plan.apply_witness(&Witness::Signature, &from0);
assert_eq!(fin_plan, FinPlan::new_authorized_payment(from1, 42, to));
}
}