# 使用RSA密钥对签名验签（PSS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.createAsyKeyGeneratorBySpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreateasykeygeneratorbyspec10)、[AsyKeyGeneratorBySpec.generateKeyPair](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#generatekeypair-3)，指定密钥参数，生成RSA非对称密钥对（KeyPair）。
   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[指定密钥参数生成非对称密钥对](crypto-generate-asym-key-pair-from-key-spec.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'RSA|PSS|SHA256|MGF1_SHA256'，创建非对称密钥类型为不带长度的RSA、填充模式为PSS、摘要算法为SHA256、掩码算法为MGF1_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. 调用[Sign.setSignSpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#setsignspec10)，设置签名参数。此处设置盐值的长度（SignSpecItem.PSS_SALT_LEN_NUM）为32字节。在验签时将校验此数据。

5. 调用[Sign.getSignSpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#getsignspec10)，获取其他签名参数。

6. 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。

7. 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'RSA2048|PSS|SHA256|MGF1_SHA256'，创建非对称密钥类型为RSA2048、填充模式为PSS、摘要算法为SHA256、掩码算法为MGF1_SHA256的Verify实例，用于完成验签操作。

2. 调用[Verify.setVerifySpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#setverifyspec10)，设置签名参数。需要与签名时设置的保持一致。

3. 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。

4. 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。

5. 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';
  // 根据密钥参数属性构造RSA非对称密钥对密钥参数
  function genRsaKeyPairSpec(nIn: bigint, eIn: bigint, dIn: bigint) {
    let rsaCommSpec: cryptoFramework.RSACommonParamsSpec = {
      n: nIn,
      algName: "RSA",
      specType: cryptoFramework.AsyKeySpecType.COMMON_PARAMS_SPEC
    };
    let rsaKeyPairSpec: cryptoFramework.RSAKeyPairSpec = {
      params: rsaCommSpec,
      sk: dIn,
      pk: eIn,
      algName: "RSA",
      specType: cryptoFramework.AsyKeySpecType.KEY_PAIR_SPEC
    };
    return rsaKeyPairSpec;
  }
  // 生成RSA2048密钥对参数
  function genRsa2048KeyPairSpec(): cryptoFramework.RSAKeyPairSpec {
    let nIn = BigInt("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");
    let eIn = BigInt("0x010001");
    let dIn = BigInt("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");
    return genRsaKeyPairSpec(nIn, eIn, dIn);
  }

  async function verifyMessagePSS() {
    // 完整的明文被拆分为input1和input2
    let plan1 = "This is Sign test plan1";
    let plan2 = "This is Sign test plan2";
    let input1: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan1, 'utf-8').buffer) };
    let input2: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan2, 'utf-8').buffer) };
    // 获得RSA密钥对密钥参数对象
    let rsaKeyPairSpec = genRsa2048KeyPairSpec();
    // 构造RSA密钥对生成器
    let rsaGeneratorSpec = cryptoFramework.createAsyKeyGeneratorBySpec(rsaKeyPairSpec);
    // sign和verfiy均支持RSA密钥带长度/不带长度的写法
    let signer = cryptoFramework.createSign("RSA|PSS|SHA256|MGF1_SHA256");
    let verifyer = cryptoFramework.createVerify("RSA2048|PSS|SHA256|MGF1_SHA256");
    let keyPair = await rsaGeneratorSpec.generateKeyPair();
    await signer.init(keyPair.priKey);
    // 在签名初始化后，对PSS参数进行set和get操作
    let setN = 32;
    signer.setSignSpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM, setN);
    let saltLen = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM);
    console.info("SaltLen == " + saltLen);
    let tf = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_TRAILER_FIELD_NUM);
    console.info("trailer field == " + tf);
    let md = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MD_NAME_STR);
    console.info("md == " + md);
    let mgf = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MGF_NAME_STR);
    console.info("mgf == " + mgf);
    let mgf1Md = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MGF1_MD_STR);
    console.info("mgf1Md == " + mgf1Md);
    await signer.update(input1);
    let signMessageBlob = await signer.sign(input2);
    // 在验签初始化前，对PSS参数进行set和get操作
    verifyer.setVerifySpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM, setN);
    saltLen = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM);
    console.info("SaltLen == " + saltLen);
    tf = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_TRAILER_FIELD_NUM);
    console.info("trailer field == " + tf);
    md = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MD_NAME_STR);
    console.info("md == " + md);
    mgf = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MGF_NAME_STR);
    console.info("mgf == " + mgf);
    mgf1Md = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MGF1_MD_STR);
    await verifyer.init(keyPair.pubKey);
    await verifyer.update(input1);
    let verifyResult = await verifyer.verify(input2, signMessageBlob);
    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';
  // 根据密钥参数属性构造RSA非对称密钥对密钥参数
  function genRsaKeyPairSpec(nIn: bigint, eIn: bigint, dIn: bigint) {
    let rsaCommSpec: cryptoFramework.RSACommonParamsSpec = {
      n: nIn,
      algName: "RSA",
      specType: cryptoFramework.AsyKeySpecType.COMMON_PARAMS_SPEC
    };
    let rsaKeyPairSpec: cryptoFramework.RSAKeyPairSpec = {
      params: rsaCommSpec,
      sk: dIn,
      pk: eIn,
      algName: "RSA",
      specType: cryptoFramework.AsyKeySpecType.KEY_PAIR_SPEC
    };
    return rsaKeyPairSpec;
  }
  // 生成RSA2048密钥对参数
  function genRsa2048KeyPairSpec(): cryptoFramework.RSAKeyPairSpec {
    let nIn = BigInt("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");
    let eIn = BigInt("0x010001");
    let dIn = BigInt("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");
    return genRsaKeyPairSpec(nIn, eIn, dIn);
  }

  function verifyMessagePSS() {
    // 完整的明文被拆分为input1和input2
    let plan1 = "This is Sign test plan1";
    let plan2 = "This is Sign test plan2";
    let input1: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan1, 'utf-8').buffer) };
    let input2: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan2, 'utf-8').buffer) };
    // 获得RSA密钥对密钥参数对象
    let rsaKeyPairSpec = genRsa2048KeyPairSpec();
    // 构造RSA密钥对生成器
    let rsaGeneratorSpec = cryptoFramework.createAsyKeyGeneratorBySpec(rsaKeyPairSpec);
    // sign和verfiy均支持RSA密钥带长度/不带长度的写法
    let signer = cryptoFramework.createSign("RSA|PSS|SHA256|MGF1_SHA256");
    let verifyer = cryptoFramework.createVerify("RSA2048|PSS|SHA256|MGF1_SHA256");
    let keyPair = rsaGeneratorSpec.generateKeyPairSync();
    signer.initSync(keyPair.priKey);
    // 在签名初始化后，对PSS参数进行set和get操作
    let setN = 32;
    signer.setSignSpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM, setN);
    let saltLen = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM);
    console.info("SaltLen == " + saltLen);
    let tf = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_TRAILER_FIELD_NUM);
    console.info("trailer field == " + tf);
    let md = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MD_NAME_STR);
    console.info("md == " + md);
    let mgf = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MGF_NAME_STR);
    console.info("mgf == " + mgf);
    let mgf1Md = signer.getSignSpec(cryptoFramework.SignSpecItem.PSS_MGF1_MD_STR);
    console.info("mgf1Md == " + mgf1Md);
    signer.updateSync(input1);
    let signMessageBlob = signer.signSync(input2);
    // 在验签初始化前，对PSS参数进行set和get操作
    verifyer.setVerifySpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM, setN);
    saltLen = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_SALT_LEN_NUM);
    console.info("SaltLen == " + saltLen);
    tf = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_TRAILER_FIELD_NUM);
    console.info("trailer field == " + tf);
    md = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MD_NAME_STR);
    console.info("md == " + md);
    mgf = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MGF_NAME_STR);
    console.info("mgf == " + mgf);
    mgf1Md = verifyer.getVerifySpec(cryptoFramework.SignSpecItem.PSS_MGF1_MD_STR);
    verifyer.initSync(keyPair.pubKey);
    verifyer.updateSync(input1);
    let verifyResult = verifyer.verifySync(input2, signMessageBlob);
    if (verifyResult == true) {
      console.info('verify success');
    } else {
      console.error('verify failed');
    }
  }
  ```