# 使用RSA密钥对分段签名验签（PKCS1模式）(ArkTS)


对应的算法规格请查看[签名验签算法规格：RSA](crypto-sign-sig-verify-overview.md#rsa)。


**签名**


1. 调用[cryptoFramework.createAsyKeyGenerator](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreateasykeygenerator)、[AsyKeyGenerator.generateKeyPair](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#generatekeypair-1)，生成密钥算法为RSA、密钥长度为1024位、素数个数为2的非对称密钥对象（KeyPair），包括公钥（PubKey）和私钥（PriKey）。
   
   如何生成RSA非对称密钥，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：RSA](crypto-asym-key-generation-conversion-spec.md#rsa)和[随机生成非对称密钥对](crypto-generate-asym-key-pair-randomly.md)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。

2. 调用[cryptoFramework.createSign](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreatesign)，指定字符串参数'RSA1024|PKCS1|SHA256'，创建非对称密钥类型为RSA1024、填充模式为PKCS1、摘要算法为SHA256的Sign实例，用于完成签名操作。

3. 调用[Sign.init](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#init-3)，使用私钥（PriKey）初始化Sign实例。

4. 将一次传入数据量设置为64字节，多次调用[Sign.update](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#update-3)，传入待签名的数据。
   当前单次update长度没有限制，开发者可以根据数据量判断如何调用update。

5. 调用[Sign.sign](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#sign-1)，生成数据签名。


**验签**


1. 调用[cryptoFramework.createVerify](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreateverify)，指定字符串参数'RSA1024|PKCS1|SHA256'，与签名的Sign实例保持一致。创建Verify实例，用于完成验签操作。

2. 调用[Verify.init](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#init-5)，使用公钥（PubKey）初始化Verify实例。

3. 调用[Verify.update](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#update-5)，传入待验证的数据。
   当前单次update长度没有限制，开发者可以根据数据量判断如何调用update。

4. 调用[Verify.verify](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#verify-1)，对数据进行验签。


- 异步方法示例：

  ```ts
  import { cryptoFramework } from '@kit.CryptoArchitectureKit';
  import { buffer } from '@kit.ArkTS';

  async function signMessageBySegment(priKey: cryptoFramework.PriKey, plainText: Uint8Array) {
    let signAlg = "RSA1024|PKCS1|SHA256";
    let signer = cryptoFramework.createSign(signAlg);
    await signer.init(priKey);
    let textSplitLen = 64; // 自定义的数据拆分长度，此处取64
    for (let i = 0; i < plainText.length; i += textSplitLen) {
      let updateMessage = plainText.subarray(i, i + textSplitLen);
      let updateMessageBlob: cryptoFramework.DataBlob = { data: updateMessage };
      // 分段update
      await signer.update(updateMessageBlob);
    }
    // 已通过分段传入所有明文，故此处sign传入null
    let signData = await signer.sign(null);
    return signData;
  }
  async function verifyMessagBySegment(pubKey: cryptoFramework.PubKey, plainText: Uint8Array, signMessageBlob: cryptoFramework.DataBlob) {
    let verifyAlg = "RSA1024|PKCS1|SHA256";
    let verifier = cryptoFramework.createVerify(verifyAlg);
    await verifier.init(pubKey);
    let textSplitLen = 64; // 自定义的数据拆分长度，此处取64
    for (let i = 0; i < plainText.length; i += textSplitLen) {
      let updateMessage = plainText.subarray(i, i + textSplitLen);
      let updateMessageBlob: cryptoFramework.DataBlob = { data: updateMessage };
      // 分段update
      await verifier.update(updateMessageBlob);
    }
    // 已通过分段传入所有明文，故此处verify第一个参数传入null
    let res = await verifier.verify(null, signMessageBlob);
    console.info("verify result is " + res);
    return res;
  }
  async function rsaSignatureBySegment() {
    let message = "This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!";
    let keyGenAlg = "RSA1024";
    let generator = cryptoFramework.createAsyKeyGenerator(keyGenAlg);
    let keyPair = await generator.generateKeyPair();
    let messageData = new Uint8Array(buffer.from(message, 'utf-8').buffer);
    let signData = await signMessageBySegment(keyPair.priKey, messageData);
    let verifyResult = await verifyMessagBySegment(keyPair.pubKey, messageData, signData);
    if (verifyResult == true) {
      console.info('verify success');
    } else {
      console.error('verify failed');
    }
  }
  ```

- 同步方法示例：

  ```ts
  import { cryptoFramework } from '@kit.CryptoArchitectureKit';
  import { buffer } from '@kit.ArkTS';

  function signMessageBySegment(priKey: cryptoFramework.PriKey, plainText: Uint8Array) {
    let signAlg = "RSA1024|PKCS1|SHA256";
    let signer = cryptoFramework.createSign(signAlg);
    signer.initSync(priKey);
    let textSplitLen = 64; // 自定义的数据拆分长度，此处取64
    for (let i = 0; i < plainText.length; i += textSplitLen) {
      let updateMessage = plainText.subarray(i, i + textSplitLen);
      let updateMessageBlob: cryptoFramework.DataBlob = { data: updateMessage };
      // 分段update
      signer.updateSync(updateMessageBlob);
    }
    // 已通过分段传入所有明文，故此处sign传入null
    let signData = signer.signSync(null);
    return signData;
  }
  function verifyMessagBySegment(pubKey: cryptoFramework.PubKey, plainText: Uint8Array, signMessageBlob: cryptoFramework.DataBlob) {
    let verifyAlg = "RSA1024|PKCS1|SHA256";
    let verifier = cryptoFramework.createVerify(verifyAlg);
    verifier.initSync(pubKey);
    let textSplitLen = 64; // 自定义的数据拆分长度，此处取64
    for (let i = 0; i < plainText.length; i += textSplitLen) {
      let updateMessage = plainText.subarray(i, i + textSplitLen);
      let updateMessageBlob: cryptoFramework.DataBlob = { data: updateMessage };
      // 分段update
      verifier.updateSync(updateMessageBlob);
    }
    // 已通过分段传入所有明文，故此处verify第一个参数传入null
    let res = verifier.verifySync(null, signMessageBlob);
    console.info("verify result is " + res);
    return res;
  }
  function rsaSignatureBySegment() {
    let message = "This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!" +
      "This is a long plainTest! This is a long plainTest! This is a long plainTest! This is a long plainTest!";
    let keyGenAlg = "RSA1024";
    let generator = cryptoFramework.createAsyKeyGenerator(keyGenAlg);
    let keyPair = generator.generateKeyPairSync();
    let messageData = new Uint8Array(buffer.from(message, 'utf-8').buffer);
    let signData = signMessageBySegment(keyPair.priKey, messageData);
    let verifyResult = verifyMessagBySegment(keyPair.pubKey, messageData, signData);
    if (verifyResult == true) {
      console.info('verify success');
    } else {
      console.error('verify failed');
    }
  }
  ```