HarmonyOS 鸿蒙Next基于加解密算法框架的常见规格问题

场景描述

对于加解密在HarmonyOS和安卓相互转换，以及HarmonyOS、安卓互调的各种场景下使用密文密钥的问题。

应用经常会遇到如下的业务诉求：

场景一：SM2加解密，安卓和HarmonyOS的sm2密文，密钥格式不符，不能直接使用，需要一定的转换。

场景二：AES加解密，缺少基础的加解密示例，在原有的文档示例基础上不知道如何修改。

方案描述

场景一：

对于使用sm2加解密，安卓生成的密钥拿到HarmonyOS使用如何导入，密文如何去转换、HarmonyOS生成的密文如何拿到安卓去解密。

方案

1、对于传入的密钥中公钥是带04的的十六进制的130位字符串，在传入的时候，密钥参数对应的格式为 04+x+y，x和y的长度是一致的，私钥的十六进制就直接放入对应的参数即可

传入不带04的十六进制的128位字符串，对应的格式就是x+y,代码中 keyStr.startsWith(“04”) ? keyStr.slice(2) : keyStr正是为了判断这个。

2、对于安卓加密的密文，HarmonyOS这边的格式是ASN.1包裹的格式，因此HarmonyOS这边解密的时候，需要先序列化：HexStrTouint8Array(new SM2_Ciphertext().i2d_SM2_Ciphertext(“安卓的密文”))；同理HarmonyOS生成的密文要先解码：new SM2_Ciphertext().d2i_SM2_Ciphertext(uint8ArrayToHexStr(HarmonyOS密文))，其中安卓的密文为十六进制字符串，HarmonyOS密文为Uint8Array数组

具体实现如下：

效果图

核心代码

根据密钥参数生成sm2私钥

export async function convertStrToPriKey(keyStr: string): Promise<cryptoFramework.PriKey> {
  let sk = BigInt(“0x” + keyStr)
  let priKeySpec: cryptoFramework.ECCPriKeySpec = {
    params: cryptoFramework.ECCKeyUtil.genECCCommonParamsSpec(‘NID_sm2’),
    sk: sk,
    algName: “SM2”,
    specType: cryptoFramework.AsyKeySpecType.PRIVATE_KEY_SPEC
  }
  let keypairGenerator = cryptoFramework.createAsyKeyGeneratorBySpec(priKeySpec)
  return await keypairGenerator.generatePriKey()
}

根据密钥参数生成sm2公钥

export async function convertStrToPubKey(keyStr: string): Promise<cryptoFramework.PubKey> {
  let pubKeyStr = keyStr.startsWith(“04”) ? keyStr.slice(2) : keyStr
  let pkPart1 = pubKeyStr.slice(0, pubKeyStr.length / 2)
  let pkPart2 = pubKeyStr.slice(pubKeyStr.length / 2)
  let pk: cryptoFramework.Point = {
    x: BigInt(“0x” + pkPart1),
    y: BigInt(“0x” + pkPart2),
  }
  let pubKeySpec: cryptoFramework.ECCPubKeySpec = {
    params: cryptoFramework.ECCKeyUtil.genECCCommonParamsSpec(‘NID_sm2’),
    pk: pk,
    algName: “SM2”,
    specType: cryptoFramework.AsyKeySpecType.PUBLIC_KEY_SPEC
  }
  let keypairGenerator = cryptoFramework.createAsyKeyGeneratorBySpec(pubKeySpec)
  return await keypairGenerator.generatePubKey()
}

加密消息

async function encryptMessagePromise(publicKey: cryptoFramework.PubKey, plainText: string) {
  let cipher = cryptoFramework.createCipher(‘SM2_256|SM3’)
  await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, publicKey, null)
  let encryptData = await cipher.doFinal({ data:stringToUint8Array(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
}

使用过程中安卓和HarmonyOS的格式转换介绍

export async function test(data: string) {
  //十六进制的公私钥
  let pubKeyStr = “0453402B95F3584F36B9A7129A6B5C6109F2DBC7C94BE7858DB66C48AF38CB5C3B76883EE4BF18E270607191E233EAC0A95ECFB8EF6FE80C5F782DE24F018DEB5F”
  let priKeyStr = “5B9270E0ADF86A101167610FCCD375A6549DC14E9225951EF3A4640F26D6CD9C”
  //安卓加密后的密文
  let a = “53ce193ad865c6d97742da78b18a21d0ca66200fe080284d774d5500915be2425cea2f310c9a423bc2d08ce5c1e78a75cfd66d88688a0e2076a45614307e4372aa10b514841cfe7bff08fc82d96bdf35754696571e5fbedd552d1ab7c54bff796a0e3fd72902”;
  //根据密钥参数生成对应的公私钥
  let pk = await convertStrToPubKey(pubKeyStr)
  let sk = await convertStrToPriKey(priKeyStr)
  //加密
  let encryptText = await encryptMessagePromise(pk, data)
  //将加密的密文数据解码转换为安卓可用数据（用于HarmonyOS和安卓的交接）
  let b = new SM2_Ciphertext().d2i_SM2_Ciphertext(uint8ArrayToHexStr(encryptText.data))
  console.log(“解码后数据=======>” + b)
  //解密得到结果
  let res = await decryptMessagePromise(sk, encryptText)
  console.log(“a=======>” + uint8ArrayToString(res.data))
  //针对安卓的密文处理，转成HarmonyOS可用uint8Array数组数据
  let c = HexStrTouint8Array(new SM2_Ciphertext().i2d_SM2_Ciphertext(a))
  //对安卓生成的的密文进行解密
  let resa = await decryptMessagePromise(sk, { data:c })
}

场景二：

缺少基础的加解密示例(AES|ECB|PKCS7 demo)

方案

对于不同的分组模式下表中给出了相应的参数适用说明，代码以AES128为例，这里的密钥传入的为base64格式，偏移量IV为字符串，对于格式的可以参考格式转换。对于GCM的参数设置，这里给了IV的，其余参数参考IV的写法即可。模板中使用的加解密算法以及密钥规格可以参考以下链接:

对称密钥加解密算法规格：https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/crypto-sym-encrypt-decrypt-spec-0000001774120458-V5?catalogVersion=V5

对称密钥生成和转换规格：https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/crypto-sym-key-generation-conversion-spec-0000001821000065-V5

分组模式	适用的加解密方式	所需参数	备注
ECB	AES、SM4、3DES	没有偏移量等参数
CBC、CTR、OFB、CFB	AES、SM4、3DES(不支持CTR)	指明加解密参数iv。 - AES的iv长度为16字节 - 3DES的iv长度为8字节 - SM4iv长度为16字节。
GCM	AES	指明加解密参数iv，长度为1~16字节，常用为12字节。指明加解密参数aad，长度为0~INT_MAX字节，常用为16字节。指明加解密参数authTag，长度为16字节。	在GCM模式下，需要从加密后的数据中取出末尾16字节，作为解密时初始化的认证信息

效果图

核心代码

ECB加解密模板

//加密
async function aesEncrypt(text:string,puKey:string): Promise<string>{
  let globalResult = “”
  try {
    //这里已AES加解密为例支持AES、SM4、3DES
    let cipherAlgName = ‘AES128|ECB|PKCS7’;
    // 创建加解密对象
    let globalCipher = cryptoFramework.createCipher(cipherAlgName);
    //这里已AES加解密为例支持AES、SM4、3DES
    let symAlgName = ‘AES128’;
    //创建密钥对象
    let symKeyGenerator = cryptoFramework.createSymKeyGenerator(symAlgName);
    //将传入的base格式的密钥转为Uint8Array数组
    let dataUint8Array = base.decodeSync(puKey)
    let keyBlob: cryptoFramework.DataBlob = { data: dataUint8Array }
    //导入外部密钥
    let promiseSymKey = await symKeyGenerator.convertKey(keyBlob)
    //初始化
    await globalCipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, promiseSymKey, null);
    //加密
    let result = await globalCipher.doFinal({data:stringToUint8Array(text)})
    //将加密结果转换为base64格式，用于保存或者传递
    globalResult = base.encodeToStringSync(result.data);
  } catch (err) {
    console.log(err.message)
  }
  return globalResult;
}
// 解密
async function aesDecrypt(text: string, key: string) {
  let globalResult = “”
  try {
    //这里已AES加解密为例支持AES、SM4、3DES
    let cipherAlgName = ‘AES128|ECB|PKCS7’;
    // 创建加解密对象
    let globalCipher = cryptoFramework.createCipher(cipherAlgName);
    //这里已AES加解密为例支持AES、SM4、3DES
    let symAlgName = ‘AES128’;
    //创建密钥对象
    let symKeyGenerator = cryptoFramework.createSymKeyGenerator(symAlgName);
    //将传入的base格式的密钥转为Uint8Array数组
    let dataUint8Array = base.decodeSync(key)
    let keyBlob: cryptoFramework.DataBlob = { data: dataUint8Array }
    //导入外部密钥
    let promiseSymKey = await symKeyGenerator.convertKey(keyBlob)
    await globalCipher.init(cryptoFramework.CryptoMode.DECRYPT_MODE, promiseSymKey, null);
    let plainText: cryptoFramework.DataBlob = { data: base.decodeSync(text) }
    let result = await globalCipher.doFinal(plainText)
    //将解密后的结果result解码之后得到明文
    globalResult = uint8ArrayToString(result.data);
    console.log(“解密后的明文==》” + globalResult)
  } catch (err) {
    console.log(err.message)
  }
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CBC加解密模板

//加密
async function aesEncrypt(text: string, key: string, iv:string): Promise<string> {
  let globalResult = “”
  try {
    //这里已AES加解密为例支持AES、SM4、3DES
    let cipherAlgName = ‘AES128|CBC|PKCS7’;
    let globalCipher = cryptoFramework.createCipher(cipherAlgName);
    //这里已AES加解密为例支持AES、SM4、3DES
    let symAlgName = ‘AES128’;
    let symKeyGenerator = cryptoFramework.createSymKeyGenerator(symAlgName);
    let dataUint8Array = base.decodeSync(key)
    let keyBlob: cryptoFramework.DataBlob = { data: dataUint8Array }
    let promiseSymKey = await symKeyGenerator.convertKey(keyBlob)
    let ivData = stringToUint8Array(iv);
    let ivdata: cryptoFramework.DataBlob = { data: ivData }; //偏移
    let iv: cryptoFramework.IvParamsSpec = { iv: ivdata, algName: ‘IvParamsSpec’ } //cbc 模式的参数
    await globalCipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, promiseSymKey, iv);
    let plainText: cryptoFramework.DataBlob = { data: this.stringToUint8Array(text) }
    let result = await globalCipher.doFinal(plainText)
    globalResult = base.encodeToStringSync(result.data);
  } catch (err) {
    console.log(err.message)
  }
  return globalResult;
}
// 解密
async function aesDecrypt(text: string, key: string,iv:string) {
  let globalResult = “”
  try {
    let cipherAlgName = ‘AES128|CBC|PKCS7’;
    let globalCipher = cryptoFramework.createCipher(cipherAlgName);
    let symAlgName = ‘AES128’;
    let symKeyGenerator = cryptoFramework.createSymKeyGenerator(symAlgName);
    let dataUint8Array = base.decodeSync(key)
    let keyBlob: cryptoFramework.DataBlob = { data: dataUint8Array }
    let promiseSymKey = await symKeyGenerator.convertKey(keyBlob)
    // /*设置偏移量 */
    let ivData = stringToUint8Array(iv);
    let ivdata: cryptoFramework.DataBlob = { data: ivData }; //偏移
    let iv: cryptoFramework.IvParamsSpec = { iv: ivdata, algName: ‘IvParamsSpec’ } //cbc 模式的参数
    await globalCipher.init(cryptoFramework.CryptoMode.DECRYPT_MODE, promiseSymKey, globalCbcParams);
    let plainText: cryptoFramework.DataBlob = { data: base.decodeSync(text) }
    let result = await globalCipher.doFinal(plainText)
    globalResult = uint8ArrayToString(result.data);
    console.log(“解密后的明文==》” + globalResult)
  } catch (err) {
    console.log(err.message)
  }
  return globalResult;
}

GCM加解密模板

//GCM的参数设置
function genGcmParamsSpec() {
  let arr = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]; // 12 bytes
  let dataIv = new Uint8Array(arr);
  let ivBlob: cryptoFramework.DataBlob = { data: dataIv };
  arr = [0, 0, 0, 0, 0, 0, 0, 0]; // 8 bytes
  let dataAad = new Uint8Array(arr);
  let aadBlob: cryptoFramework.DataBlob = { data: dataAad };
  arr = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]; // 16 bytes
  let dataTag = new Uint8Array(arr);
  let tagBlob: cryptoFramework.DataBlob = {
    data: dataTag
  };
  // GCM的authTag在加密时从doFinal结果中获取，在解密时填入init函数的params参数中
  let gcmParamsSpec: cryptoFramework.GcmParamsSpec = {
    iv: ivBlob,
    aad: aadBlob,
    authTag: tagBlob,
    algName: “GcmParamsSpec”
  };
  return gcmParamsSpec;
}
//加密
export async function aesEncryptGCM(text: string, key: string,iv:string): Promise<string> {
  let globalResult = “”
  try {
    let cipherAlgName = ‘AES128|GCM|PKCS5’;
    let globalCipher = cryptoFramework.createCipher(cipherAlgName);
    let symAlgName = ‘AES128’;
    let symKeyGenerator = cryptoFramework.createSymKeyGenerator(symAlgName);
    let dataUint8Array = stringToUint8Array(key)
    let keyBlob: cryptoFramework.DataBlob = { data: dataUint8Array }
    let promiseSymKey = await symKeyGenerator.convertKey(keyBlob)
    let getParamsSpec: cryptoFramework.GcmParamsSpec = genGcmParamsSpec();
    getParamsSpec.iv = { data: stringToUint8Array(iv) }
    await globalCipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, promiseSymKey, getParamsSpec);
    let plainText: cryptoFramework.DataBlob = { data: stringToUint8Array(text) }
    let res = await globalCipher.doFinal(plainText)
    authTag = res.data.subarray(res.data.length - 16, res.data.length)//authTag
    let a = res.data.subarray(0, res.data.length - authTag.length);//密文
    globalResult = base.encodeToStringSync(a);
  } catch (err) {
    console.log(err.message)
  }
  return globalResult;
}
// 解密
export async function aesDecryptGCM(text: string, key: string) {
  let globalResult = “”
  try {
    let cipherAlgName = ‘AES128|GCM|PKCS5’;
    let globalCipher = cryptoFramework.createCipher(cipherAlgName);
    let symAlgName = ‘AES128’;
    let symKeyGenerator = cryptoFramework.createSymKeyGenerator(symAlgName);
    let dataUint8Array = stringToUint8Array(key)
    let keyBlob: cryptoFramework.DataBlob = { data: dataUint8Array }
    let promiseSymKey = await symKeyGenerator.convertKey(keyBlob)
    let getParamsSpec: cryptoFramework.GcmParamsSpec = genGcmParamsSpec();
    getParamsSpec.authTag = {data:authTag}
    getParamsSpec.iv = { data: stringToUint8Array(iv) }
    await globalCipher.init(cryptoFramework.CryptoMode.DECRYPT_MODE, promiseSymKey, getParamsSpec);
    let plainText: cryptoFramework.DataBlob = { data: base.decodeSync(text) }
    let result = await globalCipher.doFinal(plainText)
    globalResult = uint8ArrayToString(result.data);
    console.log(“解密后的明文==》” + globalResult)
  } catch (err) {
    console.log(err.message)
  }
  return globalResult;
}