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
|
--
-- This file is part of TALER
-- Copyright (C) 2014--2022 Taler Systems SA
--
-- 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.
--
-- 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
-- TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/>
--
CREATE OR REPLACE FUNCTION exchange_do_melt(
IN in_cs_rms BYTEA,
IN in_amount_with_fee_val INT8,
IN in_amount_with_fee_frac INT4,
IN in_rc BYTEA,
IN in_old_coin_pub BYTEA,
IN in_old_coin_sig BYTEA,
IN in_known_coin_id INT8, -- not used, but that's OK
IN in_noreveal_index INT4,
IN in_zombie_required BOOLEAN,
OUT out_balance_ok BOOLEAN,
OUT out_zombie_bad BOOLEAN,
OUT out_noreveal_index INT4)
LANGUAGE plpgsql
AS $$
DECLARE
denom_max INT8;
BEGIN
-- Shards: INSERT refresh_commitments (by rc)
-- (rare:) SELECT refresh_commitments (by old_coin_pub) -- crosses shards!
-- (rare:) SEELCT refresh_revealed_coins (by melt_serial_id)
-- (rare:) PERFORM recoup_refresh (by rrc_serial) -- crosses shards!
-- UPDATE known_coins (by coin_pub)
INSERT INTO exchange.refresh_commitments
(rc
,old_coin_pub
,old_coin_sig
,amount_with_fee_val
,amount_with_fee_frac
,noreveal_index
)
VALUES
(in_rc
,in_old_coin_pub
,in_old_coin_sig
,in_amount_with_fee_val
,in_amount_with_fee_frac
,in_noreveal_index)
ON CONFLICT DO NOTHING;
IF NOT FOUND
THEN
-- Idempotency check: see if an identical record exists.
out_noreveal_index=-1;
SELECT
noreveal_index
INTO
out_noreveal_index
FROM exchange.refresh_commitments
WHERE rc=in_rc;
out_balance_ok=FOUND;
out_zombie_bad=FALSE; -- zombie is OK
RETURN;
END IF;
IF in_zombie_required
THEN
-- Check if this coin was part of a refresh
-- operation that was subsequently involved
-- in a recoup operation. We begin by all
-- refresh operations our coin was involved
-- with, then find all associated reveal
-- operations, and then see if any of these
-- reveal operations was involved in a recoup.
PERFORM
FROM exchange.recoup_refresh
WHERE rrc_serial IN
(SELECT rrc_serial
FROM exchange.refresh_revealed_coins
WHERE melt_serial_id IN
(SELECT melt_serial_id
FROM exchange.refresh_commitments
WHERE old_coin_pub=in_old_coin_pub));
IF NOT FOUND
THEN
out_zombie_bad=TRUE;
out_balance_ok=FALSE;
RETURN;
END IF;
END IF;
out_zombie_bad=FALSE; -- zombie is OK
-- Check and update balance of the coin.
UPDATE known_coins
SET
remaining_frac=remaining_frac-in_amount_with_fee_frac
+ CASE
WHEN remaining_frac < in_amount_with_fee_frac
THEN 100000000
ELSE 0
END,
remaining_val=remaining_val-in_amount_with_fee_val
- CASE
WHEN remaining_frac < in_amount_with_fee_frac
THEN 1
ELSE 0
END
WHERE coin_pub=in_old_coin_pub
AND ( (remaining_val > in_amount_with_fee_val) OR
( (remaining_frac >= in_amount_with_fee_frac) AND
(remaining_val >= in_amount_with_fee_val) ) );
IF NOT FOUND
THEN
-- Insufficient balance.
out_noreveal_index=-1;
out_balance_ok=FALSE;
RETURN;
END IF;
-- Special actions needed for a CS melt?
IF NOT NULL in_cs_rms
THEN
-- Get maximum denominations serial value in
-- existence, this will determine how long the
-- nonce will be locked.
SELECT
denominations_serial
INTO
denom_max
FROM exchange.denominations
ORDER BY denominations_serial DESC
LIMIT 1;
-- Cache CS signature to prevent replays in the future
-- (and check if cached signature exists at the same time).
INSERT INTO exchange.cs_nonce_locks
(nonce
,max_denomination_serial
,op_hash)
VALUES
(cs_rms
,denom_serial
,in_rc)
ON CONFLICT DO NOTHING;
IF NOT FOUND
THEN
-- Record exists, make sure it is the same
SELECT 1
FROM exchange.cs_nonce_locks
WHERE nonce=cs_rms
AND op_hash=in_rc;
IF NOT FOUND
THEN
-- Nonce reuse detected
out_balance_ok=FALSE;
out_zombie_bad=FALSE;
out_noreveal_index=42; -- FIXME: return error message more nicely!
ASSERT false, 'nonce reuse attempted by client';
END IF;
END IF;
END IF;
-- Everything fine, return success!
out_balance_ok=TRUE;
out_noreveal_index=in_noreveal_index;
END $$;
|
