Merge pull request #915 from 0xProject/feature/encode-decode-checks

Add strictArgumentEncodingCheck to BaseContract and use it in contract templates

3 files changed, 144 insertions, 0 deletions

diff --git a/packages/base-contract/CHANGELOG.json b/packages/base-contract/CHANGELOG.json
index 9dddde18a..b041e13da 100644
--- a/packages/base-contract/CHANGELOG.json
+++ b/packages/base-contract/CHANGELOG.json
@@ -1,5 +1,14 @@
 [
     {
+        "version": "2.0.0-rc.1",
+        "changes": [
+            {
+                "pr": 915,
+                "note": "Added strict encoding/decoding checks for sendTransaction and call"
+            }
+        ]
+    },
+    {
         "timestamp": 1532619515,
         "version": "1.0.4",
         "changes": [
diff --git a/packages/base-contract/src/index.ts b/packages/base-contract/src/index.ts
index a240fb8b6..12f974445 100644
--- a/packages/base-contract/src/index.ts
+++ b/packages/base-contract/src/index.ts
@@ -82,6 +82,27 @@ export class BaseContract {
         }
         return txDataWithDefaults;
     }
+    // Throws if the given arguments cannot be safely/correctly encoded based on
+    // the given inputAbi. An argument may not be considered safely encodeable
+    // if it overflows the corresponding Solidity type, there is a bug in the
+    // encoder, or the encoder performs unsafe type coercion.
+    public static strictArgumentEncodingCheck(inputAbi: DataItem[], args: any[]): void {
+        const coder = ethers.utils.AbiCoder.defaultCoder;
+        const params = abiUtils.parseEthersParams(inputAbi);
+        const rawEncoded = coder.encode(params.names, params.types, args);
+        const rawDecoded = coder.decode(params.names, params.types, rawEncoded);
+        for (let i = 0; i < rawDecoded.length; i++) {
+            const original = args[i];
+            const decoded = rawDecoded[i];
+            if (!abiUtils.isAbiDataEqual(params.names[i], params.types[i], original, decoded)) {
+                throw new Error(
+                    `Cannot safely encode argument: ${params.names[i]} (${original}) of type ${
+                        params.types[i]
+                    }. (Possible type overflow or other encoding error)`,
+                );
+            }
+        }
+    }
     protected _lookupEthersInterface(functionSignature: string): ethers.Interface {
         const ethersInterface = this._ethersInterfacesByFunctionSignature[functionSignature];
         if (_.isUndefined(ethersInterface)) {
diff --git a/packages/base-contract/test/base_contract_test.ts b/packages/base-contract/test/base_contract_test.ts
new file mode 100644
index 000000000..2c31d1f11
--- /dev/null
+++ b/packages/base-contract/test/base_contract_test.ts
@@ -0,0 +1,114 @@
+import * as chai from 'chai';
+import 'mocha';
+
+import { BaseContract } from '../src';
+
+const { expect } = chai;
+
+describe('BaseContract', () => {
+    describe('strictArgumentEncodingCheck', () => {
+        it('works for simple types', () => {
+            BaseContract.strictArgumentEncodingCheck(
+                [{ name: 'to', type: 'address' }],
+                ['0xe834ec434daba538cd1b9fe1582052b880bd7e63'],
+            );
+        });
+        it('works for array types', () => {
+            const inputAbi = [
+                {
+                    name: 'takerAssetFillAmounts',
+                    type: 'uint256[]',
+                },
+            ];
+            const args = [
+                ['9000000000000000000', '79000000000000000000', '979000000000000000000', '7979000000000000000000'],
+            ];
+            BaseContract.strictArgumentEncodingCheck(inputAbi, args);
+        });
+        it('works for tuple/struct types', () => {
+            const inputAbi = [
+                {
+                    components: [
+                        {
+                            name: 'makerAddress',
+                            type: 'address',
+                        },
+                        {
+                            name: 'takerAddress',
+                            type: 'address',
+                        },
+                        {
+                            name: 'feeRecipientAddress',
+                            type: 'address',
+                        },
+                        {
+                            name: 'senderAddress',
+                            type: 'address',
+                        },
+                        {
+                            name: 'makerAssetAmount',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'takerAssetAmount',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'makerFee',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'takerFee',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'expirationTimeSeconds',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'salt',
+                            type: 'uint256',
+                        },
+                        {
+                            name: 'makerAssetData',
+                            type: 'bytes',
+                        },
+                        {
+                            name: 'takerAssetData',
+                            type: 'bytes',
+                        },
+                    ],
+                    name: 'order',
+                    type: 'tuple',
+                },
+            ];
+            const args = [
+                {
+                    makerAddress: '0x6ecbe1db9ef729cbe972c83fb886247691fb6beb',
+                    takerAddress: '0x0000000000000000000000000000000000000000',
+                    feeRecipientAddress: '0xe834ec434daba538cd1b9fe1582052b880bd7e63',
+                    senderAddress: '0x0000000000000000000000000000000000000000',
+                    makerAssetAmount: '0',
+                    takerAssetAmount: '200000000000000000000',
+                    makerFee: '1000000000000000000',
+                    takerFee: '1000000000000000000',
+                    expirationTimeSeconds: '1532563026',
+                    salt: '59342956082154660870994022243365949771115859664887449740907298019908621891376',
+                    makerAssetData: '0xf47261b00000000000000000000000001dc4c1cefef38a777b15aa20260a54e584b16c48',
+                    takerAssetData: '0xf47261b00000000000000000000000001d7022f5b17d2f8b695918fb48fa1089c9f85401',
+                },
+            ];
+            BaseContract.strictArgumentEncodingCheck(inputAbi, args);
+        });
+        it('throws for integer overflows', () => {
+            expect(() =>
+                BaseContract.strictArgumentEncodingCheck([{ name: 'amount', type: 'uint8' }], ['256']),
+            ).to.throw();
+        });
+        it('throws for fixed byte array overflows', () => {
+            expect(() =>
+                BaseContract.strictArgumentEncodingCheck([{ name: 'hash', type: 'bytes8' }], ['0x001122334455667788']),
+            ).to.throw();
+        });
+    });
+});