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
|
import { AssetProxyId, ERC20AssetData, ERC721AssetData } from '@0xproject/types';
import { BigNumber, NULL_BYTES } from '@0xproject/utils';
import BN = require('bn.js');
import ethUtil = require('ethereumjs-util');
import * as _ from 'lodash';
const ERC20_ASSET_DATA_BYTE_LENGTH = 21;
const ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH = 53;
const ASSET_DATA_ADDRESS_OFFSET = 0;
const ERC721_ASSET_DATA_TOKEN_ID_OFFSET = 20;
const ERC721_ASSET_DATA_RECEIVER_DATA_LENGTH_OFFSET = 52;
const ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET = 84;
export const assetProxyUtils = {
encodeAssetProxyId(assetProxyId: AssetProxyId): Buffer {
return ethUtil.toBuffer(assetProxyId);
},
decodeAssetProxyId(encodedAssetProxyId: Buffer): AssetProxyId {
return ethUtil.bufferToInt(encodedAssetProxyId);
},
encodeAddress(address: string): Buffer {
if (!ethUtil.isValidAddress(address)) {
throw new Error(`Invalid Address: ${address}`);
}
const encodedAddress = ethUtil.toBuffer(address);
return encodedAddress;
},
decodeAddress(encodedAddress: Buffer): string {
const address = ethUtil.bufferToHex(encodedAddress);
if (!ethUtil.isValidAddress(address)) {
throw new Error(`Invalid Address: ${address}`);
}
return address;
},
encodeUint256(value: BigNumber): Buffer {
const base = 10;
const formattedValue = new BN(value.toString(base));
const encodedValue = ethUtil.toBuffer(formattedValue);
// tslint:disable-next-line:custom-no-magic-numbers
const paddedValue = ethUtil.setLengthLeft(encodedValue, 32);
return paddedValue;
},
decodeUint256(encodedValue: Buffer): BigNumber {
const formattedValue = ethUtil.bufferToHex(encodedValue);
const value = new BigNumber(formattedValue, 16);
return value;
},
encodeERC20AssetData(tokenAddress: string): string {
const encodedAssetProxyId = assetProxyUtils.encodeAssetProxyId(AssetProxyId.ERC20);
const encodedAddress = assetProxyUtils.encodeAddress(tokenAddress);
const encodedAssetData = Buffer.concat([encodedAddress, encodedAssetProxyId]);
const encodedAssetDataHex = ethUtil.bufferToHex(encodedAssetData);
return encodedAssetDataHex;
},
decodeERC20AssetData(proxyData: string): ERC20AssetData {
const encodedAssetData = ethUtil.toBuffer(proxyData);
if (encodedAssetData.byteLength !== ERC20_ASSET_DATA_BYTE_LENGTH) {
throw new Error(
`Could not decode ERC20 Proxy Data. Expected length of encoded data to be 21. Got ${
encodedAssetData.byteLength
}`,
);
}
const assetProxyIdOffset = encodedAssetData.byteLength - 1;
const encodedAssetProxyId = encodedAssetData.slice(assetProxyIdOffset);
const assetProxyId = assetProxyUtils.decodeAssetProxyId(encodedAssetProxyId);
if (assetProxyId !== AssetProxyId.ERC20) {
throw new Error(
`Could not decode ERC20 Proxy Data. Expected Asset Proxy Id to be ERC20 (${
AssetProxyId.ERC20
}), but got ${assetProxyId}`,
);
}
const encodedTokenAddress = encodedAssetData.slice(ASSET_DATA_ADDRESS_OFFSET, assetProxyIdOffset);
const tokenAddress = assetProxyUtils.decodeAddress(encodedTokenAddress);
const erc20AssetData = {
assetProxyId,
tokenAddress,
};
return erc20AssetData;
},
encodeERC721AssetData(tokenAddress: string, tokenId: BigNumber, receiverData?: string): string {
const encodedAssetProxyId = assetProxyUtils.encodeAssetProxyId(AssetProxyId.ERC721);
const encodedAddress = assetProxyUtils.encodeAddress(tokenAddress);
const encodedTokenId = assetProxyUtils.encodeUint256(tokenId);
let encodedAssetData = Buffer.concat([encodedAddress, encodedTokenId]);
if (!_.isUndefined(receiverData)) {
const encodedReceiverData = ethUtil.toBuffer(receiverData);
const receiverDataLength = new BigNumber(encodedReceiverData.byteLength);
const encodedReceiverDataLength = assetProxyUtils.encodeUint256(receiverDataLength);
encodedAssetData = Buffer.concat([encodedAssetData, encodedReceiverDataLength, encodedReceiverData]);
}
encodedAssetData = Buffer.concat([encodedAssetData, encodedAssetProxyId]);
const encodedAssetDataHex = ethUtil.bufferToHex(encodedAssetData);
return encodedAssetDataHex;
},
decodeERC721AssetData(assetData: string): ERC721AssetData {
const encodedAssetData = ethUtil.toBuffer(assetData);
if (encodedAssetData.byteLength < ERC721_ASSET_DATA_MINIMUM_BYTE_LENGTH) {
throw new Error(
`Could not decode ERC20 Proxy Data. Expected length of encoded data to be at least 53. Got ${
encodedAssetData.byteLength
}`,
);
}
const encodedTokenAddress = encodedAssetData.slice(
ASSET_DATA_ADDRESS_OFFSET,
ERC721_ASSET_DATA_TOKEN_ID_OFFSET,
);
const proxyIdOffset = encodedAssetData.byteLength - 1;
const encodedAssetProxyId = encodedAssetData.slice(proxyIdOffset);
const assetProxyId = assetProxyUtils.decodeAssetProxyId(encodedAssetProxyId);
if (assetProxyId !== AssetProxyId.ERC721) {
throw new Error(
`Could not decode ERC721 Proxy Data. Expected Asset Proxy Id to be ERC721 (${
AssetProxyId.ERC721
}), but got ${assetProxyId}`,
);
}
const tokenAddress = assetProxyUtils.decodeAddress(encodedTokenAddress);
const encodedTokenId = encodedAssetData.slice(
ERC721_ASSET_DATA_TOKEN_ID_OFFSET,
ERC721_ASSET_DATA_RECEIVER_DATA_LENGTH_OFFSET,
);
const tokenId = assetProxyUtils.decodeUint256(encodedTokenId);
let receiverData = NULL_BYTES;
const lengthUpToReceiverDataLength = ERC721_ASSET_DATA_RECEIVER_DATA_LENGTH_OFFSET + 1;
if (encodedAssetData.byteLength > lengthUpToReceiverDataLength) {
const encodedReceiverDataLength = encodedAssetData.slice(
ERC721_ASSET_DATA_RECEIVER_DATA_LENGTH_OFFSET,
ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET,
);
const receiverDataLength = assetProxyUtils.decodeUint256(encodedReceiverDataLength);
const lengthUpToReceiverData = ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET + 1;
const expectedReceiverDataLength = new BigNumber(encodedAssetData.byteLength - lengthUpToReceiverData);
if (!receiverDataLength.equals(expectedReceiverDataLength)) {
throw new Error(
`Data length (${receiverDataLength}) does not match actual length of data (${expectedReceiverDataLength})`,
);
}
const encodedReceiverData = encodedAssetData.slice(
ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET,
receiverDataLength.add(ERC721_ASSET_DATA_RECEIVER_DATA_OFFSET).toNumber(),
);
receiverData = ethUtil.bufferToHex(encodedReceiverData);
}
const erc721AssetData: ERC721AssetData = {
assetProxyId,
tokenAddress,
tokenId,
receiverData,
};
return erc721AssetData;
},
decodeAssetDataId(assetData: string): AssetProxyId {
const encodedAssetData = ethUtil.toBuffer(assetData);
if (encodedAssetData.byteLength < 1) {
throw new Error(
`Could not decode Proxy Data. Expected length of encoded data to be at least 1. Got ${
encodedAssetData.byteLength
}`,
);
}
const encodedAssetProxyId = encodedAssetData.slice(-1);
const assetProxyId = assetProxyUtils.decodeAssetProxyId(encodedAssetProxyId);
return assetProxyId;
},
decodeAssetData(assetData: string): ERC20AssetData | ERC721AssetData {
const assetProxyId = assetProxyUtils.decodeAssetDataId(assetData);
switch (assetProxyId) {
case AssetProxyId.ERC20:
const erc20AssetData = assetProxyUtils.decodeERC20AssetData(assetData);
return erc20AssetData;
case AssetProxyId.ERC721:
const erc721AssetData = assetProxyUtils.decodeERC721AssetData(assetData);
return erc721AssetData;
default:
throw new Error(`Unrecognized asset proxy id: ${assetProxyId}`);
}
},
};
|
