Feat/fill OTC Order with Permit (#186)

* constructFillOrderDirectly/allow for takerPermit

* constructApproveTokenForLimitOrder/approveTakerTokenForFillingP2POrderDirectly

* test helpers/extends buyErc20TokenForEth

* tests/fix comments

* tests/LO/fill OTC directly

* tests/LO/more helpers

* tests/LO/fill OTC directly with Permit

* helpers/splitSignature

* helper/encodeEIP_2612PermitFunctionInput

* fillOrderDirectly/handle EIP2612 takerPermit

* test/LO/OTC with Permit

* helpers/encodeDAIlikePermitFunctionInput

* lOrder/fillOrderDirectly/handle DAI Permit and pre-encoded permit params

* test/LOrder/fill OTC with DAI Permit

* cleanup

* test/LO/reenable tests

* update snapshots

src/methods/common/orders/encoding.ts

@@ -0,0 +1,216 @@
+import { splitSignature } from './signature';
+
+type EncodeEIP_2612PermitFunctionInput = {
+  permitSignature: string;
+  owner: string;
+  spender: string;
+  value: string | bigint;
+  deadline: string | number | bigint;
+};
+
+// encoding params for Token.permit() Permit1 function
+export function encodeEIP_2612PermitFunctionInput({
+  owner,
+  spender,
+  value,
+  deadline,
+  permitSignature,
+}: EncodeEIP_2612PermitFunctionInput): string {
+  const { v, r, s } = splitSignature(permitSignature);
+
+  const encodedOwner = encodeAddress(owner);
+  const encodedSpender = encodeAddress(spender);
+  const encodedValue = encodeUint256(value);
+  const encodedDeadline = encodeUint256(deadline.toString());
+  const encodedV = encodeUint8(v);
+  const encodedR = encodeBytes32(r);
+  const encodedS = encodeBytes32(s);
+
+  // Concatenate all encoded values, stripping the "0x" prefix from each (except the first one)
+  return (
+    '0x' +
+    [
+      encodedOwner,
+      encodedSpender,
+      encodedValue,
+      encodedDeadline,
+      encodedV,
+      encodedR,
+      encodedS,
+    ]
+      .map((val) => val.slice(2)) // Remove "0x" prefix from each encoded value
+      .join('') // Concatenate the values
+  );
+}
+
+type EncodeDAIlikePermitFunctionInput = {
+  permitSignature: string;
+  holder: string;
+  spender: string;
+  nonce: number | bigint | string;
+  expiry: number | bigint | string;
+};
+
+// encoding params for DAIlike.permit() function
+export function encodeDAIlikePermitFunctionInput({
+  permitSignature,
+  holder,
+  spender,
+  nonce,
+  expiry,
+}: EncodeDAIlikePermitFunctionInput): string {
+  const { v, r, s } = splitSignature(permitSignature);
+
+  const encodedHolder = encodeAddress(holder);
+  const encodedSpender = encodeAddress(spender);
+  const encodedNonce = encodeUint256(nonce.toString());
+  const encodedExpiry = encodeUint256(expiry.toString());
+  const encodedV = encodeUint8(v);
+  const encodedR = encodeBytes32(r);
+  const encodedS = encodeBytes32(s);
+
+  // Concatenate all encoded values, stripping the "0x" prefix from each (except the first one)
+  return (
+    '0x' +
+    [
+      encodedHolder,
+      encodedSpender,
+      encodedNonce,
+      encodedExpiry,
+      encodeBool(true), //allowed=true
+      encodedV,
+      encodedR,
+      encodedS,
+    ]
+      .map((val) => val.slice(2)) // Remove "0x" prefix from each encoded value
+      .join('') // Concatenate the values
+  );
+}
+
+// encode an address (20 bytes) into 32 bytes
+export function encodeAddress(address: string): string {
+  const strippedAddress = address.replace(/^0x/, ''); // Remove "0x" prefix
+  return '0x' + strippedAddress.toLowerCase().padStart(64, '0');
+}
+
+// encode a uint256 value
+export function encodeUint256(value: string | bigint): string {
+  const bn = BigInt(value);
+  return '0x' + bn.toString(16).padStart(64, '0');
+}
+
+// encode a uint8 value
+export function encodeUint8(value: number | bigint): string {
+  return '0x' + value.toString(16).padStart(64, '0');
+}
+
+// encode a bytes32 value
+export function encodeBytes32(value: string): string {
+  const strippedValue = value.replace(/^0x/, ''); // Remove "0x" prefix
+  return '0x' + strippedValue.padStart(64, '0').toLowerCase();
+}
+
+//encode a boolean
+export function encodeBool(value: boolean): string {
+  const encodedValue = value ? '1' : '0';
+  // padded to 32 bytes
+  return '0x' + encodedValue.padStart(64, '0');
+}
+
+/* 
+const EIP_2612_PERMIT_ABI = [
+  {
+    constant: false,
+    inputs: [
+      {
+        name: 'owner',
+        type: 'address',
+      },
+      {
+        name: 'spender',
+        type: 'address',
+      },
+      {
+        name: 'value',
+        type: 'uint256',
+      },
+      {
+        name: 'deadline',
+        type: 'uint256',
+      },
+      {
+        name: 'v',
+        type: 'uint8',
+      },
+      {
+        name: 'r',
+        type: 'bytes32',
+      },
+      {
+        name: 's',
+        type: 'bytes32',
+      },
+    ],
+    name: 'permit',
+    outputs: [],
+    payable: false,
+    stateMutability: 'nonpayable',
+    type: 'function',
+  },
+]; 
+*/
+
+/* 
+const DAI_EIP_2612_PERMIT_ABI = [
+  {
+    constant: false,
+    inputs: [
+      {
+        internalType: 'address',
+        name: 'holder',
+        type: 'address',
+      },
+      {
+        internalType: 'address',
+        name: 'spender',
+        type: 'address',
+      },
+      {
+        internalType: 'uint256',
+        name: 'nonce',
+        type: 'uint256',
+      },
+      {
+        internalType: 'uint256',
+        name: 'expiry',
+        type: 'uint256',
+      },
+      {
+        internalType: 'bool',
+        name: 'allowed',
+        type: 'bool',
+      },
+      {
+        internalType: 'uint8',
+        name: 'v',
+        type: 'uint8',
+      },
+      {
+        internalType: 'bytes32',
+        name: 'r',
+        type: 'bytes32',
+      },
+      {
+        internalType: 'bytes32',
+        name: 's',
+        type: 'bytes32',
+      },
+    ],
+    name: 'permit',
+    outputs: [],
+    payable: false,
+    stateMutability: 'nonpayable',
+    type: 'function',
+  },
+];
+ */

src/methods/common/orders/signature.ts

@@ -0,0 +1,68 @@
+type SplitSignatureResult = {
+  v: number;
+  r: string;
+  s: string;
+  compact: string;
+};
+
+export function splitSignature(signature: string): SplitSignatureResult {
+  // Remove "0x" prefix if present
+  if (signature.startsWith('0x')) {
+    signature = signature.slice(2);
+  }
+
+  // Convert the hex string to a byte array
+  const bytes = new Uint8Array(signature.length / 2);
+  for (let i = 0; i < signature.length; i += 2) {
+    bytes[i / 2] = parseInt(signature.slice(i, i + 2), 16);
+  }
+
+  // Validate the signature length (64 or 65 bytes)
+  if (bytes.length !== 64 && bytes.length !== 65) {
+    throw new Error('Invalid signature length: must be 64 or 65 bytes');
+  }
+
+  // Extract r and s components
+  const r = `0x${Array.from(bytes.slice(0, 32), (b) =>
+    b.toString(16).padStart(2, '0')
+  ).join('')}`;
+  let s: string;
+  let v;
+
+  // Handle 64-byte (EIP-2098 compact) and 65-byte signatures
+  if (bytes.length === 64) {
+    // Extract v from the highest bit of s and clear the bit in s
+    v = 27 + (bytes[32]! >> 7);
+    bytes[32]! &= 0x7f; // Clear the highest bit
+    s = `0x${Array.from(bytes.slice(32, 64))
+      .map((b) => b.toString(16).padStart(2, '0'))
+      .join('')}`;
+  } else {
+    s = `0x${Array.from(bytes.slice(32, 64))
+      .map((b) => b.toString(16).padStart(2, '0'))
+      .join('')}`;
+
+    // Extract v directly for 65-byte signature
+    v = bytes[64]!;
+
+    // Normalize v to canonical form (27 or 28)
+    if (v < 27) {
+      v += 27;
+    }
+  }
+
+  // Compute yParityAndS (_vs) for the compact signature
+  const sBytes = Array.from(bytes.slice(32, 64));
+  if (v === 28) {
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    sBytes[0]! |= 0x80; // Set the highest bit if v is 28
+  }
+  const yParityAndS = `0x${sBytes
+    .map((b) => b.toString(16).padStart(2, '0'))
+    .join('')}`;
+
+  // Construct the compact signature by concatenating r and yParityAndS
+  const compactSignature = r + yParityAndS.slice(2);
+
+  return { v, r, s, compact: compactSignature };
+}

src/methods/limitOrders/approveForOrder.ts

@@ -6,6 +6,8 @@ import { constructGetSpender } from '../swap/spender';
 export type ApproveTokenForLimitOrderFunctions<T> = {
   /** @description approving AugustusRFQ as spender for makerAsset */
   approveMakerTokenForLimitOrder: ApproveToken<T>;
+  /** @description approving AugustusRFQ as spender for takerAsset to call SDK.fillOrderDirectly */
+  approveTakerTokenForFillingP2POrderDirectly: ApproveToken<T>;
   /** @description approving AugustusSwapper as spender for takerAsset for Limit Orders that will be executed through it */
   approveTakerTokenForLimitOrder: ApproveToken<T>;
 };
@@ -28,6 +30,7 @@ export const constructApproveTokenForLimitOrder = <T>(
 
   return {
     approveMakerTokenForLimitOrder,
+    approveTakerTokenForFillingP2POrderDirectly: approveMakerTokenForLimitOrder,
     approveTakerTokenForLimitOrder,
   };
 };