diff options
Diffstat (limited to 'packages/utils/src/sign_typed_data_utils.ts')
-rw-r--r-- | packages/utils/src/sign_typed_data_utils.ts | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/packages/utils/src/sign_typed_data_utils.ts b/packages/utils/src/sign_typed_data_utils.ts new file mode 100644 index 000000000..6963b9084 --- /dev/null +++ b/packages/utils/src/sign_typed_data_utils.ts @@ -0,0 +1,82 @@ +import * as ethUtil from 'ethereumjs-util'; +import * as ethers from 'ethers'; +import * as _ from 'lodash'; + +import { EIP712Object, EIP712ObjectValue, EIP712TypedData, EIP712Types } from '@0x/types'; + +export const signTypedDataUtils = { + /** + * Generates the EIP712 Typed Data hash for signing + * @param typedData An object that conforms to the EIP712TypedData interface + * @return A Buffer containing the hash of the typed data. + */ + generateTypedDataHash(typedData: EIP712TypedData): Buffer { + return ethUtil.sha3( + Buffer.concat([ + Buffer.from('1901', 'hex'), + signTypedDataUtils._structHash('EIP712Domain', typedData.domain, typedData.types), + signTypedDataUtils._structHash(typedData.primaryType, typedData.message, typedData.types), + ]), + ); + }, + _findDependencies(primaryType: string, types: EIP712Types, found: string[] = []): string[] { + if (found.includes(primaryType) || types[primaryType] === undefined) { + return found; + } + found.push(primaryType); + for (const field of types[primaryType]) { + for (const dep of signTypedDataUtils._findDependencies(field.type, types, found)) { + if (!found.includes(dep)) { + found.push(dep); + } + } + } + return found; + }, + _encodeType(primaryType: string, types: EIP712Types): string { + let deps = signTypedDataUtils._findDependencies(primaryType, types); + deps = deps.filter(d => d !== primaryType); + deps = [primaryType].concat(deps.sort()); + let result = ''; + for (const dep of deps) { + result += `${dep}(${types[dep].map(({ name, type }) => `${type} ${name}`).join(',')})`; + } + return result; + }, + _encodeData(primaryType: string, data: EIP712Object, types: EIP712Types): string { + const encodedTypes = ['bytes32']; + const encodedValues: Array<Buffer | EIP712ObjectValue> = [signTypedDataUtils._typeHash(primaryType, types)]; + for (const field of types[primaryType]) { + const value = data[field.name]; + if (field.type === 'string' || field.type === 'bytes') { + const hashValue = ethUtil.sha3(value as string); + encodedTypes.push('bytes32'); + encodedValues.push(hashValue); + } else if (types[field.type] !== undefined) { + encodedTypes.push('bytes32'); + const hashValue = ethUtil.sha3( + // tslint:disable-next-line:no-unnecessary-type-assertion + signTypedDataUtils._encodeData(field.type, value as EIP712Object, types), + ); + encodedValues.push(hashValue); + } else if (field.type.lastIndexOf(']') === field.type.length - 1) { + throw new Error('Arrays currently unimplemented in encodeData'); + } else { + encodedTypes.push(field.type); + const normalizedValue = signTypedDataUtils._normalizeValue(field.type, value); + encodedValues.push(normalizedValue); + } + } + return ethers.utils.defaultAbiCoder.encode(encodedTypes, encodedValues); + }, + _normalizeValue(type: string, value: any): EIP712ObjectValue { + const normalizedValue = type === 'uint256' && _.isObject(value) && value.isBigNumber ? value.toString() : value; + return normalizedValue; + }, + _typeHash(primaryType: string, types: EIP712Types): Buffer { + return ethUtil.sha3(signTypedDataUtils._encodeType(primaryType, types)); + }, + _structHash(primaryType: string, data: EIP712Object, types: EIP712Types): Buffer { + return ethUtil.sha3(signTypedDataUtils._encodeData(primaryType, data, types)); + }, +}; |