rewrite eip712 auth

derekpierre · May 27, 2024 · d091e6b · d091e6b
1 parent a5d6419
commit d091e6b
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Showing 3 changed files with 85 additions and 58 deletions.
diff --git a/packages/taco-auth/src/eip712.ts b/packages/taco-auth/src/eip712.ts
@@ -2,7 +2,9 @@ import type { TypedDataSigner } from '@ethersproject/abstract-signer';
 import { ethers } from 'ethers';
 import { utils as ethersUtils } from 'ethers/lib/ethers';
 
-export interface Eip712TypedData {
+import { LocalStorage } from './storage';
+
+interface Eip712 {
   types: {
     Wallet: { name: string; type: string }[];
   };
@@ -20,17 +22,17 @@ export interface Eip712TypedData {
   };
 }
 
-export interface FormattedTypedData extends Eip712TypedData {
+interface FormattedEip712 extends Eip712 {
   primaryType: 'Wallet';
   types: {
     EIP712Domain: { name: string; type: string }[];
     Wallet: { name: string; type: string }[];
   };
 }
 
-export interface TypedSignature {
+interface TypedSignature {
   signature: string;
-  typedData: Eip712TypedData;
+  typedData: Eip712;
   address: string;
 }
 
@@ -40,47 +42,48 @@ interface ChainData {
   blockNumber: number;
 }
 
-export class WalletAuthenticationProvider {
-  private walletSignature?: Record<string, string>;
+const EIP712Domain = [
+  {
+    name: 'name',
+    type: 'string',
+  },
+  {
+    name: 'version',
+    type: 'string',
+  },
+  {
+    name: 'chainId',
+    type: 'uint256',
+  },
+  {
+    name: 'salt',
+    type: 'bytes32',
+  },
+];
+
+export class EIP712SignatureProvider {
+  private readonly storage: LocalStorage;
 
   constructor(
     private readonly provider: ethers.providers.Provider,
     private readonly signer: ethers.Signer,
-  ) {}
+  ) {
+    this.storage = new LocalStorage();
+  }
 
   public async getOrCreateWalletSignature(): Promise<TypedSignature> {
     const address = await this.signer.getAddress();
-    const storageKey = `wallet-signature-${address}`;
+    const storageKey = `eip712-signature-${address}`;
 
     // If we have a signature in localStorage, return it
-    const isLocalStorage = typeof localStorage !== 'undefined';
-    if (isLocalStorage) {
-      const maybeSignature = localStorage.getItem(storageKey);
-      if (maybeSignature) {
-        return JSON.parse(maybeSignature);
-      }
-    }
-
-    // If not, try returning from memory
-    const maybeSignature = this.walletSignature?.[address];
+    const maybeSignature = this.storage.getItem(storageKey);
     if (maybeSignature) {
-      if (isLocalStorage) {
-        localStorage.setItem(storageKey, maybeSignature);
-      }
       return JSON.parse(maybeSignature);
     }
 
     // If at this point we didn't return, we need to create a new signature
     const typedSignature = await this.createWalletSignature();
-
-    // Persist where you can
-    if (isLocalStorage) {
-      localStorage.setItem(storageKey, JSON.stringify(typedSignature));
-    }
-    if (!this.walletSignature) {
-      this.walletSignature = {};
-    }
-    this.walletSignature[address] = JSON.stringify(typedSignature);
+    this.storage.setItem(storageKey, JSON.stringify(typedSignature));
     return typedSignature;
   }
 
@@ -91,7 +94,7 @@ export class WalletAuthenticationProvider {
     const signatureText = `I'm the owner of address ${address} as of block number ${blockNumber}`;
     const salt = ethersUtils.hexlify(ethersUtils.randomBytes(32));
 
-    const typedData: Eip712TypedData = {
+    const typedData: Eip712 = {
       types: {
         Wallet: [
           { name: 'address', type: 'address' },
@@ -118,29 +121,12 @@ export class WalletAuthenticationProvider {
       this.signer as unknown as TypedDataSigner
     )._signTypedData(typedData.domain, typedData.types, typedData.message);
 
-    const formattedTypedData: FormattedTypedData = {
+    const formattedTypedData: FormattedEip712 = {
       ...typedData,
       primaryType: 'Wallet',
       types: {
         ...typedData.types,
-        EIP712Domain: [
-          {
-            name: 'name',
-            type: 'string',
-          },
-          {
-            name: 'version',
-            type: 'string',
-          },
-          {
-            name: 'chainId',
-            type: 'uint256',
-          },
-          {
-            name: 'salt',
-            type: 'bytes32',
-          },
-        ],
+        EIP712Domain,
       },
     };
     return { signature, typedData: formattedTypedData, address };

diff --git a/packages/taco-auth/src/storage.ts b/packages/taco-auth/src/storage.ts
@@ -0,0 +1,44 @@
+interface IStorage {
+  getItem(key: string): string | null;
+
+  setItem(key: string, value: string): void;
+}
+
+class BrowserStorage implements IStorage {
+  getItem(key: string): string | null {
+    return localStorage.getItem(key);
+  }
+
+  setItem(key: string, value: string): void {
+    localStorage.setItem(key, value);
+  }
+}
+
+
+class NodeStorage implements IStorage {
+  private storage: Record<string, string> = {};
+
+  getItem(key: string): string | null {
+    return this.storage[key] || null;
+  }
+
+  setItem(key: string, value: string): void {
+    this.storage[key] = value;
+  }
+}
+
+export class LocalStorage {
+  private storage: IStorage;
+
+  constructor() {
+    this.storage = typeof localStorage === 'undefined' ? new NodeStorage() : new BrowserStorage();
+  }
+
+  getItem(key: string): string | null {
+    return this.storage.getItem(key);
+  }
+
+  setItem(key: string, value: string): void {
+    this.storage.setItem(key, value);
+  }
+}
diff --git a/packages/taco/src/conditions/context/context.ts b/packages/taco/src/conditions/context/context.ts
@@ -1,9 +1,6 @@
 import { Context, Conditions as WASMConditions } from '@nucypher/nucypher-core';
 import { fromJSON, toJSON } from '@nucypher/shared';
-import {
-  TypedSignature,
-  WalletAuthenticationProvider,
-} from '@nucypher/taco-auth';
+import { EIP712SignatureProvider, TypedSignature } from '@nucypher/taco-auth';
 import { ethers } from 'ethers';
 
 import { CompoundConditionType } from '../compound-condition';
@@ -30,7 +27,7 @@ const ERR_UNKNOWN_CONTEXT_PARAMS = (params: string[]) =>
   `Unknown custom context parameter(s): ${params.join(', ')}`;
 
 export class ConditionContext {
-  private readonly walletAuthProvider?: WalletAuthenticationProvider;
+  private readonly eip712SignatureProvider?: EIP712SignatureProvider;
 
   constructor(
     private readonly provider: ethers.providers.Provider,
@@ -39,7 +36,7 @@ export class ConditionContext {
     private readonly signer?: ethers.Signer,
   ) {
     if (this.signer) {
-      this.walletAuthProvider = new WalletAuthenticationProvider(
+      this.eip712SignatureProvider = new EIP712SignatureProvider(
         this.provider,
         this.signer,
       );
@@ -99,11 +96,11 @@ export class ConditionContext {
 
     // Fill in predefined context parameters
     if (requestedParameters.has(USER_ADDRESS_PARAM)) {
-      if (!this.walletAuthProvider) {
+      if (!this.eip712SignatureProvider) {
         throw new Error(ERR_SIGNER_REQUIRED);
       }
       parameters[USER_ADDRESS_PARAM] =
-        await this.walletAuthProvider.getOrCreateWalletSignature();
+        await this.eip712SignatureProvider.getOrCreateWalletSignature();
       // Remove from requested parameters
       requestedParameters.delete(USER_ADDRESS_PARAM);
     }