Merge pull request #10 from 0xProject/addSchemas

Add schema validation

package.json

@@ -33,6 +33,7 @@
   "devDependencies": {
     "@types/bignumber.js": "^4.0.2",
     "@types/chai": "^3.5.2",
+    "@types/jsonschema": "^1.1.1",
     "@types/mocha": "^2.2.41",
     "@types/node": "^7.0.22",
     "awesome-typescript-loader": "^3.1.3",
@@ -54,6 +55,7 @@
   "dependencies": {
     "bignumber.js": "^4.0.2",
     "ethereumjs-util": "^5.1.1",
+    "jsonschema": "^1.1.1",
     "lodash": "^4.17.4",
     "web3": "^0.19.0"
   }

src/ts/0x.js.ts

@@ -1,6 +1,7 @@
 import * as BigNumber from 'bignumber.js';
 import * as ethUtil from 'ethereumjs-util';
 import {assert} from './utils/assert';
+import {ECSignatureSchema} from './schemas/ec_signature_schema';
 
 /**
  * Elliptic Curve signature
@@ -20,7 +21,7 @@ export class ZeroEx {
      */
     public static isValidSignature(data: string, signature: ECSignature, signer: ETHAddressHex): boolean {
         assert.isString('data', data);
-        assert.isObject('signature', signature);
+        assert.doesConformToSchema('signature', signature, ECSignatureSchema);
         assert.isETHAddressHex('signer', signer);
 
         const dataBuff = ethUtil.toBuffer(data);

src/ts/globals.d.ts

@@ -2,6 +2,10 @@ declare type ETHPublicKey = string;
 declare type ETHAddressHex = string;
 declare type ETHAddressBuff = Buffer;
 
+declare interface Schema {
+    id: string;
+}
+
 declare module 'ethereumjs-util' {
     const toBuffer: (data: string) => Buffer;
     const hashPersonalMessage: (msg: Buffer) => Buffer;

src/ts/schemas/ec_signature_schema.ts

@@ -0,0 +1,20 @@
+export const ECSignatureParameter = {
+    id: '/ECSignatureParameter',
+    type: 'string',
+    pattern: '^0[xX][0-9A-Fa-f]{64}$',
+};
+
+export const ECSignatureSchema = {
+    id: '/ECSignature',
+    properties: {
+        v: {
+            type: 'number',
+            minimum: 27,
+            maximum: 28,
+        },
+        r: {$ref: '/ECSignatureParameter'},
+        s: {$ref: '/ECSignatureParameter'},
+    },
+    required: ['v', 'r', 's'],
+    type: 'object',
+};

src/ts/utils/assert.ts

@@ -1,6 +1,7 @@
 import * as _ from 'lodash';
 import * as BigNumber from 'bignumber.js';
 import Web3 = require('web3');
+import {SchemaValidator} from './schema_validator';
 
 export const assert = {
     isBigNumber(variableName: string, value: BigNumber.BigNumber) {
@@ -14,12 +15,18 @@ export const assert = {
         const web3 = new Web3();
         this.assert(web3.isAddress(value), this.typeAssertionMessage(variableName, 'ETHAddressHex', value));
     },
-    isObject(variableName: string, value: object) {
-        this.assert(_.isObject(value), this.typeAssertionMessage(variableName, 'object', value));
-    },
     isNumber(variableName: string, value: number) {
         this.assert(_.isFinite(value), this.typeAssertionMessage(variableName, 'number', value));
     },
+    doesConformToSchema(variableName: string, value: object, schema: Schema) {
+        const schemaValidator = new SchemaValidator();
+        const validationResult = schemaValidator.validate(value, schema);
+        const hasValidationErrors = validationResult.errors.length > 0;
+        const msg = `Expected ${variableName} to conform to schema ${schema.id}
+Encountered: ${JSON.stringify(value, null, '\t')}
+Validation errors: ${validationResult.errors.join(', ')}`;
+        this.assert(!hasValidationErrors, msg);
+    },
     assert(condition: boolean, message: string) {
         if (!condition) {
             throw new Error(message);

src/ts/utils/schema_validator.ts

@@ -0,0 +1,14 @@
+import {Validator, ValidatorResult} from 'jsonschema';
+import {ECSignatureSchema, ECSignatureParameter} from '../schemas/ec_signature_schema';
+
+export class SchemaValidator {
+    private validator: Validator;
+    constructor() {
+        this.validator = new Validator();
+        this.validator.addSchema(ECSignatureParameter, ECSignatureParameter.id);
+        this.validator.addSchema(ECSignatureSchema, ECSignatureSchema.id);
+    }
+    public validate(instance: object, schema: Schema): ValidatorResult {
+        return this.validator.validate(instance, schema);
+    }
+}

test/0x.js.ts

@@ -14,15 +14,14 @@ describe('ZeroEx library', () => {
             s: '0x2d887fd3b17bfdce3481f10bea41f45ba9f709d39ce8325427b57afcfc994cee',
         };
         const address = '0x9b2055d370f73ec7d8a03e965129118dc8f5bf83';
-        describe('should return false for malformed signature', () => {
+        describe('should throw if passed a malformed signature', () => {
             it('malformed v', () => {
                 const malformedSignature = {
                     v: 34,
                     r: signature.r,
                     s: signature.s,
                 };
-                const isValid = ZeroEx.isValidSignature(data, malformedSignature, address);
-                expect(isValid).to.be.false;
+                expect(() => ZeroEx.isValidSignature(data, malformedSignature, address)).to.throw();
             });
             it('r lacks 0x prefix', () => {
                 const malformedR = signature.r.replace('0x', '');
@@ -31,18 +30,16 @@ describe('ZeroEx library', () => {
                     r: malformedR,
                     s: signature.s,
                 };
-                const isValid = ZeroEx.isValidSignature(data, malformedSignature, address);
-                expect(isValid).to.be.false;
+                expect(() => ZeroEx.isValidSignature(data, malformedSignature, address)).to.throw();
             });
             it('r is too short', () => {
                 const malformedR = signature.r.substr(10);
                 const malformedSignature = {
                     v: signature.v,
                     r: malformedR,
-                    s: signature.s,
+                    s: signature.s.replace('0', 'z'),
                 };
-                const isValid = ZeroEx.isValidSignature(data, malformedSignature, address);
-                expect(isValid).to.be.false;
+                expect(() => ZeroEx.isValidSignature(data, malformedSignature, address)).to.throw();
             });
             it('s is not hex', () => {
                 const malformedS = signature.s.replace('0', 'z');
@@ -51,8 +48,7 @@ describe('ZeroEx library', () => {
                     r: signature.r,
                     s: malformedS,
                 };
-                const isValid = ZeroEx.isValidSignature(data, malformedSignature, address);
-                expect(isValid).to.be.false;
+                expect(() => ZeroEx.isValidSignature(data, malformedSignature, address)).to.throw();
             });
         });
         it('should return false if the data doesn\'t pertain to the signature & address', () => {