kisa-seed

Typescript implementation of the KISA SEED encryption and decryption

KISA SEED Algorithm

This is a typescript conversion of the Java class mentioned in the above website.

Since it is almost a direct translation, it will not follow typescript standards and best practices.

Installation

npm install kisa-seed

Usage

You can use it in the following way.

import { KISA_SEED_CBC } from "kisa-seed";

const enc = KISA_SEED_CBC.encrypt(
  "gONPjwgQcPHp85Q3CtQFiQ==",
  "II1mpzCoGoFvutn6NhAlAQ==",
  "Hello World"
);

const dec = KISA_SEED_CBC.decrypt(
  "gONPjwgQcPHp85Q3CtQFiQ==",
  "II1mpzCoGoFvutn6NhAlAQ==",
  enc
);

console.log(dec);

[!NOTE] encrypt/decrypt are for UTF-8 text. decrypt throws a TypeError if the decrypted plaintext is not valid UTF-8 (e.g. certificates or other binary data), instead of silently corrupting it. For binary payloads use encryptBytes/decryptBytes.

Binary data

If your plaintext is binary (files, certificates, etc.), use encryptBytes and decryptBytes, which take the same base64 key/IV but work with Uint8Array payloads:

import { KISA_SEED_CBC } from "kisa-seed";

const data: Uint8Array = new Uint8Array([0x30, 0x82, 0xff, 0xfe]);

const enc = KISA_SEED_CBC.encryptBytes(
  "gONPjwgQcPHp85Q3CtQFiQ==",
  "II1mpzCoGoFvutn6NhAlAQ==",
  data
); // base64 ciphertext

const dec = KISA_SEED_CBC.decryptBytes(
  "gONPjwgQcPHp85Q3CtQFiQ==",
  "II1mpzCoGoFvutn6NhAlAQ==",
  enc
); // Uint8Array, byte-identical to data

You can also access an inner method if you want to directly encrypt/decrypt a Uint8Array

import { KISA_SEED_CBC } from "kisa-seed";

function stringToUint8Array(str: string): Uint8Array {
  const encoder = new TextEncoder(); // TextEncoder encodes into UTF-8 by default
  const uint8Array = encoder.encode(str);
  return uint8Array;
}

function uint8ArrayToString(uint8Array: Uint8Array): string {
  const decoder = new TextDecoder("utf-8");
  return decoder.decode(uint8Array);
}

function base64ToUint8Array(base64: string): Uint8Array {
  return new Uint8Array(Buffer.from(base64, "base64"));
}

const pbUserKey = base64ToUint8Array("gONPjwgQcPHp85Q3CtQFiQ==");
const bszIV = base64ToUint8Array("II1mpzCoGoFvutn6NhAlAQ==");
const encStr = stringToUint8Array("Hello World");

const enc = KISA_SEED_CBC.SEED_CBC_Encrypt(
  pbUserKey,
  bszIV,
  encStr,
  0,
  encStr.length
);

const dec = KISA_SEED_CBC.SEED_CBC_Decrypt(
  pbUserKey,
  bszIV,
  enc,
  0,
  enc.length
);

console.log(uint8ArrayToString(dec));