predict.gno

 1package zkgm
 2
 3import (
 4	"crypto/keccak256"
 5	"encoding/hex"
 6
 7	abi "gno.land/p/onbloc/encoding/abi"
 8	types "gno.land/p/onbloc/ibc/union/types"
 9	u256 "gno.land/p/onbloc/math/uint256"
10)
11
12const (
13	ibcDenomPrefix = "ibc/"
14	tagCallProxy   = "ZKGM_CALL_PROXY"
15)
16
17// PredictWrappedToken derives the legacy wrapped IBC denom for a v1 token order.
18func PredictWrappedToken(path *u256.Uint, channelId uint32, baseToken []byte) string {
19	if path == nil {
20		path = u256.Zero()
21	}
22
23	bz, err := abi.Encode(PredictWrappedTokenSchema, []any{path, channelId, baseToken})
24	if err != nil {
25		panic(err)
26	}
27
28	h := keccak256.Sum256(bz)
29
30	return ibcDenomPrefix + hex.EncodeToString(h[:20])
31}
32
33// PredictWrappedTokenV2 derives the IBC voucher denom for a v2 token order.
34func PredictWrappedTokenV2(path *u256.Uint, channelId uint32, baseToken []byte, metadataImage [32]byte) string {
35	if path == nil {
36		path = u256.Zero()
37	}
38
39	image := u256.Zero().SetBytes(metadataImage[:])
40
41	bz, err := abi.Encode(PredictV2Schema, []any{path, channelId, baseToken, image})
42	if err != nil {
43		panic(err)
44	}
45
46	h := keccak256.Sum256(bz)
47
48	return ibcDenomPrefix + hex.EncodeToString(h[:20])
49}
50
51// MetadataImage returns keccak256(TokenMetadata), the on-chain identity of the
52// metadata used to mint a voucher.
53func MetadataImage(meta TokenMetadata) [32]byte {
54	bz, err := EncodeTokenMetadata(meta)
55	if err != nil {
56		panic(err)
57	}
58
59	return keccak256.Sum256(bz)
60}
61
62// Uint256FromBytes32 converts a big-endian bytes32 value into a uint256.
63func Uint256FromBytes32(bz [32]byte) *u256.Uint {
64	return u256.Zero().SetBytes(bz[:])
65}
66
67// PredictCallProxyAccount returns the synthetic Gno address that represents
68// the given (path, destinationChannel, sender) tuple as a callable account.
69//
70// key = zkgm1<first-20-bytes-of-keccak(ZKGM_CALL_PROXY || path || channelId || sender)>
71func PredictCallProxyAccount(path *u256.Uint, channelId types.ChannelId, sender []byte) string {
72	var pathBytes [32]byte
73	if path != nil {
74		pathBytes = Uint256ToBytes32(path)
75	}
76
77	channel := channelId.String()
78	buf := make([]byte, 0, len(tagCallProxy)+len(pathBytes)+len(channel)+len(sender))
79	buf = append(buf, tagCallProxy...)
80	buf = append(buf, pathBytes[:]...)
81	buf = append(buf, channel...)
82	buf = append(buf, sender...)
83
84	h := keccak256.Sum256(buf)
85
86	return "zkgm1" + hex.EncodeToString(h[:20])
87}