使用SM2非对称密钥加解密
对应的算法规格请查看非对称密钥加解密算法规格:SM2。
加密
-
调用cryptoFramework.createAsyKeyGenerator、AsyKeyGenerator.generateKeyPair,生成RSA密钥类型为SM2_256的非对称密钥对(KeyPair)。KeyPair对象中包括公钥PubKey、私钥PriKey。
如何生成SM2非对称密钥对,开发者可参考下文示例,并结合非对称密钥生成和转换规格:SM2和随机生成非对称密钥对理解,参考文档与当前示例可能存在入参差异,请在阅读时注意区分。
-
调用cryptoFramework.createCipher,指定字符串参数'SM2_256|SM3',创建非对称密钥类型为SM2_256、摘要算法为SM3的Cipher实例,用于完成加解密操作。
-
调用Cipher.init,设置模式为加密(CryptoMode.ENCRYPT_MODE),指定加密密钥(KeyPair.PubKey),初始化加密Cipher实例。
非对称密钥无加密参数,直接传入null。
-
调用Cipher.doFinal,传入明文,获取加密后的数据。
- doFinal输出结果可能为null,在访问具体数据前,需要先判断结果是否为null,避免产生异常。
- 当数据量较大时,可以多次调用doFinal,即分段加解密。
解密
-
由于SM2算法的Cipher实例不支持重复init操作,需要调用cryptoFramework.createCipher,重新生成Cipher实例。
-
调用Cipher.init,设置模式为解密(CryptoMode.DECRYPT_MODE),指定解密密钥(KeyPair.PriKey)初始化解密Cipher实例。SM2无加密参数,直接传入null。
-
调用Cipher.doFinal,传入密文,获取解密后的数据。
import cryptoFramework from '@ohos.security.cryptoFramework';
import buffer from '@ohos.buffer';
// 加密消息
async function encryptMessagePromise(publicKey: cryptoFramework.PubKey, plainText: cryptoFramework.DataBlob) {
let cipher = cryptoFramework.createCipher('SM2_256|SM3');
await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, publicKey, null);
let encryptData = await cipher.doFinal(plainText);
return encryptData;
}
// 解密消息
async function decryptMessagePromise(privateKey: cryptoFramework.PriKey, cipherText: cryptoFramework.DataBlob) {
let decoder = cryptoFramework.createCipher('SM2_256|SM3');
await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, privateKey, null);
let decryptData = await decoder.doFinal(cipherText);
return decryptData;
}
// 生成SM2密钥对
async function genKeyPairByData(pubKeyData: Uint8Array, priKeyData: Uint8Array) {
let pubKeyBlob: cryptoFramework.DataBlob = { data: pubKeyData };
let priKeyBlob: cryptoFramework.DataBlob = { data: priKeyData };
let sm2Generator = cryptoFramework.createAsyKeyGenerator('SM2_256');
let keyPair = await sm2Generator.convertKey(pubKeyBlob, priKeyBlob);
console.info('convertKey success');
return keyPair;
}
async function main() {
let pkData = new Uint8Array([48, 89, 48, 19, 6, 7, 42, 134, 72, 206, 61, 2, 1, 6, 8, 42, 129, 28, 207, 85, 1, 130, 45, 3, 66, 0, 4, 90, 3, 58, 157, 190, 248, 76, 7, 132, 200, 151, 208, 112, 230, 96, 140, 90, 238, 211, 155, 128, 109, 248, 40, 83, 214, 78, 42, 104, 106, 55, 148, 249, 35, 61, 32, 221, 135, 143, 100, 45, 97, 194, 176, 52, 73, 136, 174, 40, 70, 70, 34, 103, 103, 161, 99, 27, 187, 13, 187, 109, 244, 13, 7]);
let skData = new Uint8Array([48, 49, 2, 1, 1, 4, 32, 54, 41, 239, 240, 63, 188, 134, 113, 31, 102, 149, 203, 245, 89, 15, 15, 47, 202, 170, 60, 38, 154, 28, 169, 189, 100, 251, 76, 112, 223, 156, 159, 160, 10, 6, 8, 42, 129, 28, 207, 85, 1, 130, 45]);
let keyPair = await genKeyPairByData(pkData, skData);
let pubKey = keyPair.pubKey;
let priKey = keyPair.priKey;
let message = 'This is a test';
// 把字符串按utf-8解码为Uint8Array
let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(message, 'utf-8').buffer) };
let encryptText = await encryptMessagePromise(pubKey, plainText);
let decryptText = await decryptMessagePromise(priKey, encryptText);
if (plainText.data.toString() === decryptText.data.toString()) {
console.info('decrypt ok');
// 把Uint8Array按utf-8编码为字符串
let messageDecrypted = buffer.from(decryptText.data).toString('utf-8');
console.info('decrypted result string:' + messageDecrypted);
} else {
console.error('decrypt failed');
}
}