feat: add ezwel seed encoder/decoder method

src/crypto-util/crypto-util.spec.ts

@@ -1,3 +1,4 @@
+import { TextEncoder } from 'node:util';
 import { CryptoUtil } from './crypto-util';
 
 describe('CryptoUtil', () => {
@@ -49,4 +50,19 @@ describe('CryptoUtil', () => {
       expect(result).toEqual(new TextEncoder().encode('hello world'));
     });
   });
+
+  describe('ezwelSeed', () => {
+    it('should return encrypted string', () => {
+      const data = '{"code": "hello world", "message": "안녕하세요"}';
+      const r1 = CryptoUtil.encodeSeedString(data, { seedKey: 'string_x_sixteen' });
+      expect(r1).toBe('LUPvDxmJToRCZcl56a7j+b1X1NV+6PMiBLm7SkLALDqyIfqCsHla0jkDuzoIn60G52VI68uIO51li9JAFsksAA==');
+    });
+
+    it('should return decrypted string', () => {
+      const data = 'LUPvDxmJToRCZcl56a7j+b1X1NV+6PMiBLm7SkLALDqyIfqCsHla0jkDuzoIn60G52VI68uIO51li9JAFsksAA==';
+      const r1 = CryptoUtil.decodeSeedString(data, { seedKey: 'string_x_sixteen' });
+      expect(r1.trim()).toBe('{"code": "hello world", "message": "안녕하세요"}');
+      expect(JSON.parse(r1)).toEqual({ code: 'hello world', message: '안녕하세요' });
+    });
+  });
 });

src/crypto-util/crypto-util.ts

@@ -1,3 +1,5 @@
+import { TextEncoder } from 'node:util';
+import { CryptoJS, buildHexString } from './ezwel-seed';
 import type { webcrypto } from 'crypto';
 
 const crypto = (globalThis as any).crypto as typeof webcrypto;
@@ -36,4 +38,24 @@ export namespace CryptoUtil {
   export const decodeBase64 = (data: string): Uint8Array => {
     return Uint8Array.from(atob(data), (c) => c.charCodeAt(0));
   };
+
+  export const encodeSeedString = (data: string, { seedKey }: { seedKey: string }): string => {
+    const encoded = CryptoJS.enc.Utf8.parse(data);
+    const key = CryptoJS.enc.Hex.parse(buildHexString(seedKey));
+    const encrypted = CryptoJS.SEED.encrypt(encoded, key, {
+      mode: CryptoJS.mode.ECB,
+      padding: CryptoJS.pad.ZeroPadding,
+    });
+    return encrypted.toString();
+  };
+
+  export const decodeSeedString = (hash: string, { seedKey }: { seedKey: string }): string => {
+    const key = CryptoJS.enc.Hex.parse(buildHexString(seedKey));
+    const decrypted = CryptoJS.SEED.decrypt(hash, key, {
+      mode: CryptoJS.mode.ECB,
+      padding: CryptoJS.pad.ZeroPadding,
+    });
+    const decoded = CryptoJS.enc.Utf8.stringify(decrypted);
+    return decoded.replaceAll(/\x00/g, '');
+  };
 }

src/crypto-util/ezwel-seed.d.ts

@@ -0,0 +1,2 @@
+export const CryptoJS: any;
+export function buildHexString(text: string): string;