EP: Add LibSignature library (#21)

* `@0x/contracts-zero-ex`: Add `LibSignature` library

* `@0x/contracts-zero-ex`: Update package.json scripts

Co-authored-by: Lawrence Forman <me@merklejerk.com>

contracts/zero-ex/test/artifacts.ts

@@ -51,6 +51,7 @@ import * as LibOwnableStorage from '../test/generated-artifacts/LibOwnableStorag
 import * as LibProxyRichErrors from '../test/generated-artifacts/LibProxyRichErrors.json';
 import * as LibProxyStorage from '../test/generated-artifacts/LibProxyStorage.json';
 import * as LibReentrancyGuardStorage from '../test/generated-artifacts/LibReentrancyGuardStorage.json';
+import * as LibSignature from '../test/generated-artifacts/LibSignature.json';
 import * as LibSignatureRichErrors from '../test/generated-artifacts/LibSignatureRichErrors.json';
 import * as LibSignedCallData from '../test/generated-artifacts/LibSignedCallData.json';
 import * as LibSimpleFunctionRegistryRichErrors from '../test/generated-artifacts/LibSimpleFunctionRegistryRichErrors.json';
@@ -90,6 +91,7 @@ import * as TestFillQuoteTransformerExchange from '../test/generated-artifacts/T
 import * as TestFillQuoteTransformerHost from '../test/generated-artifacts/TestFillQuoteTransformerHost.json';
 import * as TestFullMigration from '../test/generated-artifacts/TestFullMigration.json';
 import * as TestInitialMigration from '../test/generated-artifacts/TestInitialMigration.json';
+import * as TestLibSignature from '../test/generated-artifacts/TestLibSignature.json';
 import * as TestLibTokenSpender from '../test/generated-artifacts/TestLibTokenSpender.json';
 import * as TestMetaTransactionsTransformERC20Feature from '../test/generated-artifacts/TestMetaTransactionsTransformERC20Feature.json';
 import * as TestMigrator from '../test/generated-artifacts/TestMigrator.json';
@@ -153,6 +155,7 @@ export const artifacts = {
     TokenSpenderFeature: TokenSpenderFeature as ContractArtifact,
     TransformERC20Feature: TransformERC20Feature as ContractArtifact,
     UniswapFeature: UniswapFeature as ContractArtifact,
+    LibSignature: LibSignature as ContractArtifact,
     LibSignedCallData: LibSignedCallData as ContractArtifact,
     LibTokenSpender: LibTokenSpender as ContractArtifact,
     FixinCommon: FixinCommon as ContractArtifact,
@@ -208,6 +211,7 @@ export const artifacts = {
     TestFillQuoteTransformerHost: TestFillQuoteTransformerHost as ContractArtifact,
     TestFullMigration: TestFullMigration as ContractArtifact,
     TestInitialMigration: TestInitialMigration as ContractArtifact,
+    TestLibSignature: TestLibSignature as ContractArtifact,
     TestLibTokenSpender: TestLibTokenSpender as ContractArtifact,
     TestMetaTransactionsTransformERC20Feature: TestMetaTransactionsTransformERC20Feature as ContractArtifact,
     TestMigrator: TestMigrator as ContractArtifact,

contracts/zero-ex/test/lib_signature_test.ts

@@ -0,0 +1,98 @@
+import { blockchainTests, expect } from '@0x/contracts-test-utils';
+import { hexUtils } from '@0x/utils';
+import * as ethjs from 'ethereumjs-util';
+
+import { SignatureValidationError, SignatureValidationErrorCodes } from '../src/revert_errors';
+import { eip712SignHashWithKey, ethSignHashWithKey, SignatureType } from '../src/signature_utils';
+
+import { artifacts } from './artifacts';
+import { TestLibSignatureContract } from './wrappers';
+
+const EMPTY_REVERT = 'reverted with no data';
+
+blockchainTests.resets('LibSignature library', env => {
+    let testLib: TestLibSignatureContract;
+    let signerKey: string;
+    let signer: string;
+
+    before(async () => {
+        signerKey = hexUtils.random();
+        signer = ethjs.bufferToHex(ethjs.privateToAddress(ethjs.toBuffer(signerKey)));
+        testLib = await TestLibSignatureContract.deployFrom0xArtifactAsync(
+            artifacts.TestLibSignature,
+            env.provider,
+            env.txDefaults,
+            artifacts,
+        );
+    });
+
+    describe('getSignerOfHash()', () => {
+        it('can recover the signer of an EIP712 signature', async () => {
+            const hash = hexUtils.random();
+            const sig = eip712SignHashWithKey(hash, signerKey);
+            const recovered = await testLib.getSignerOfHash(hash, sig).callAsync();
+            expect(recovered).to.eq(signer);
+        });
+
+        it('can recover the signer of an EthSign signature', async () => {
+            const hash = hexUtils.random();
+            const sig = ethSignHashWithKey(hash, signerKey);
+            const recovered = await testLib.getSignerOfHash(hash, sig).callAsync();
+            expect(recovered).to.eq(signer);
+        });
+
+        it('throws if the signature type is out of range', async () => {
+            const hash = hexUtils.random();
+            const badType = (Object.values(SignatureType).slice(-1)[0] as number) + 1;
+            const sig = {
+                ...ethSignHashWithKey(hash, signerKey),
+                signatureType: badType,
+            };
+            return expect(testLib.getSignerOfHash(hash, sig).callAsync()).to.be.rejectedWith(EMPTY_REVERT);
+        });
+
+        it('throws if the signature data is malformed', async () => {
+            const hash = hexUtils.random();
+            const sig = {
+                ...ethSignHashWithKey(hash, signerKey),
+                v: 1,
+            };
+            return expect(testLib.getSignerOfHash(hash, sig).callAsync()).to.revertWith(
+                new SignatureValidationError(SignatureValidationErrorCodes.BadSignatureData, hash),
+            );
+        });
+
+        it('throws if an EC value is out of range', async () => {
+            const hash = hexUtils.random();
+            const sig = {
+                ...ethSignHashWithKey(hash, signerKey),
+                r: '0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141',
+            };
+            return expect(testLib.getSignerOfHash(hash, sig).callAsync()).to.revertWith(
+                new SignatureValidationError(SignatureValidationErrorCodes.BadSignatureData, hash),
+            );
+        });
+
+        it('throws if the type is Illegal', async () => {
+            const hash = hexUtils.random();
+            const sig = {
+                ...ethSignHashWithKey(hash, signerKey),
+                signatureType: SignatureType.Illegal,
+            };
+            return expect(testLib.getSignerOfHash(hash, sig).callAsync()).to.revertWith(
+                new SignatureValidationError(SignatureValidationErrorCodes.Illegal, hash),
+            );
+        });
+
+        it('throws if the type is Invalid', async () => {
+            const hash = hexUtils.random();
+            const sig = {
+                ...ethSignHashWithKey(hash, signerKey),
+                signatureType: SignatureType.Invalid,
+            };
+            return expect(testLib.getSignerOfHash(hash, sig).callAsync()).to.revertWith(
+                new SignatureValidationError(SignatureValidationErrorCodes.AlwaysInvalid, hash),
+            );
+        });
+    });
+});

contracts/zero-ex/test/wrappers.ts

@@ -49,6 +49,7 @@ export * from '../test/generated-wrappers/lib_ownable_storage';
 export * from '../test/generated-wrappers/lib_proxy_rich_errors';
 export * from '../test/generated-wrappers/lib_proxy_storage';
 export * from '../test/generated-wrappers/lib_reentrancy_guard_storage';
+export * from '../test/generated-wrappers/lib_signature';
 export * from '../test/generated-wrappers/lib_signature_rich_errors';
 export * from '../test/generated-wrappers/lib_signed_call_data';
 export * from '../test/generated-wrappers/lib_simple_function_registry_rich_errors';
@@ -88,6 +89,7 @@ export * from '../test/generated-wrappers/test_fill_quote_transformer_exchange';
 export * from '../test/generated-wrappers/test_fill_quote_transformer_host';
 export * from '../test/generated-wrappers/test_full_migration';
 export * from '../test/generated-wrappers/test_initial_migration';
+export * from '../test/generated-wrappers/test_lib_signature';
 export * from '../test/generated-wrappers/test_lib_token_spender';
 export * from '../test/generated-wrappers/test_meta_transactions_transform_erc20_feature';
 export * from '../test/generated-wrappers/test_migrator';