WebCrypto RSA-OAEP 密钥包裹与文件加密协作实践

概述混合加密将对称密钥用非对称算法包裹。本文演示 RSA-OAEP + AES-GCM 的端到端协作。生成与导入密钥async function genRSA() {

return crypto.subtle.generateKey({ name:'RSA-OAEP', modulusLength: 2048, publicExponent: new Uint8Array([1,0,1]), hash: 'SHA-256' }, true, ['encrypt','decrypt']);

}

async function genAES() { return crypto.subtle.generateKey({ name:'AES-GCM', length:256 }, true, ['encrypt','decrypt']); }

包裹与解包async function wrapAES(aesKey, rsaPublic) {

const raw = await crypto.subtle.exportKey('raw', aesKey);

return crypto.subtle.encrypt({ name:'RSA-OAEP' }, rsaPublic, raw);

}

async function unwrapAES(wrapped, rsaPrivate) {

const raw = await crypto.subtle.decrypt({ name:'RSA-OAEP' }, rsaPrivate, wrapped);

return crypto.subtle.importKey('raw', raw, { name:'AES-GCM' }, true, ['encrypt','decrypt']);

}

文件加解密async function encryptFile(aesKey, file) {

const iv = crypto.getRandomValues(new Uint8Array(12));

const ab = await file.arrayBuffer();

const buf = await crypto.subtle.encrypt({ name:'AES-GCM', iv }, aesKey, ab);

return { iv, bytes: new Uint8Array(buf) };

}

async function decryptBytes(aesKey, iv, bytes) {

const buf = await crypto.subtle.decrypt({ name:'AES-GCM', iv }, aesKey, bytes);

return new Uint8Array(buf);

}