javascript deriveKey和deriveBits()由主密钥派生出新的密钥进行加密
deriveKey 方法的完整示例，演示如何使用 HMAC 作为密钥派生函数（KDF）来从一个给定的秘密（如密码）派生出一个新的 AES 加密密钥。
//创建一个函数来生成随机盐function getRandomSalt(length){let array=new Uint8Array(length);window.crypto.getRandomValues(array);return array;}//生成随机数字function randomFloat(){const fooArray=new Uint32Array(1);const maxUint32=0xFFFFFFFF;return crypto.getRandomValues(fooArray)[0];}//生成随机密码，导入密钥当中function getKeyMaterial(){//const password=window.prompt("请输入你的密码");//就是为加密时用密码//这里不用输入密码，我们采用随机生成的数字，这样可以增加破解难度，提升安全性const password=randomFloat();const enc=new TextEncoder();return window.crypto.subtle.importKey("raw",enc.encode(password),"PBKDF2",false,["deriveBits","deriveKey"]);}
//创建一个函数来派生密钥async function deriveAeskey(salt,info,keyLength){//生成已有密钥//不能直接用new Textcoder().encoder(password)这样来生成密码，必须用这个函数的importKey导入密钥才行const passwordBuffer=await getKeyMaterial();const derivedKey=await crypto.subtle.deriveKey({name:'PBKDF2',salt:salt,iterations:10000,hash:'SHA-256'},passwordBuffer,{name:'AES-GCM',length:keyLength},true,["encrypt","decrypt"]);return derivedKey;}//使用派生的密钥进行加密async function encryptData(derivedKey,dataToEncrypt){const encoder=new TextEncoder();const dataBuffer=encoder.encode(dataToEncrypt);const iv=window.crypto.getRandomValues(new Uint8Array(12));const encryption=await crypto.subtle.encrypt({name:'AES-GCM',iv:iv},derivedKey,dataBuffer);return {ciphertext:encryption,iv:Array.from(iv)}}//使用派生的密钥进行解密async function decryptData(derivedKey,ciphertext,iv){const decrypted=await crypto.subtle.decrypt({name:'AES-GCM',iv:new Uint8Array(iv)},derivedKey,ciphertext);const decoder=new TextDecoder();return decoder.decode(decrypted);}//最后把他们综合到一起，进行加密和解密，以及做加密后内容的演式(async function(){const salt=getRandomSalt(16);const info=new Uint8Array();const keyLength=256;try{//派生的密钥const derivedKey=await deriveAeskey(salt,info,keyLength);//需要加密的数据const dataToEncrypt="this is data";const {ciphertext,iv}=await encryptData(derivedKey,dataToEncrypt);//这里是演式你加密后的数据样式console.log(String.fromCharCode(...new Uint8Array(ciphertext)));//解密数据const decryptedData=await decryptData(derivedKey,ciphertext,iv);console.log('解密数据：',decryptedData);}catch(error){console.log('加解密时发生错误',error);}})();