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1# 使用RSA非对称密钥（PKCS1_OAEP模式）加解密
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4对应的算法规格请查看[非对称密钥加解密算法规格：RSA](crypto-asym-encrypt-decrypt-spec.md#rsa)。
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7**加密**
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101. 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）。
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12   如何生成RSA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：RSA](crypto-asym-key-generation-conversion-spec.md#rsa)和[指定密钥参数生成密钥对](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。
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142. 调用[cryptoFramework.createCipher](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreatecipher)，指定字符串参数'RSA|PKCS1_OAEP|SHA256|MGF1_SHA1'，创建非对称密钥类型为RSA1024、填充模式为PKCS1_OAEP、摘要算法为SHA256、掩码摘要为MGF1_SHA1的RSA密钥的Cipher实例，用于完成加解密操作。
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163. 调用[Cipher.init](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#init-1)，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。
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18   非对称密钥无加密参数，直接传入null。
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204. 在调用Cipher.doFinal前，调用[Cipher.setCipherSpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#setcipherspec10)设置PKCS1_OAEP填充参数pSource。调用[Cipher.getCipherSpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#getcipherspec10)可获得OAEP相关参数。
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225. 调用[Cipher.doFinal](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#dofinal-1)，传入明文，获取加密后的数据。
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25**解密**
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281. 由于RSA算法的Cipher实例不支持重复init操作，需要调用[cryptoFramework.createCipher](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#cryptoframeworkcreatecipher)，重新生成Cipher实例。
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302. 调用[Cipher.init](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#init-1)，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。PKCS1模式无加密参数，直接传入null。
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323. 在调用Cipher.doFinal前，调用[Cipher.setCipherSpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#setcipherspec10)设置PKCS1_OAEP填充参数pSource，此处需要和加密时设置的保持一致。调用[Cipher.getCipherSpec](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#getcipherspec10)可获得OAEP相关参数。
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344. 调用[Cipher.doFinal](../../reference/apis-crypto-architecture-kit/js-apis-cryptoFramework.md#dofinal-1)，传入密文，获取解密后的数据。
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37```ts
38import cryptoFramework from '@ohos.security.cryptoFramework';
39import buffer from '@ohos.buffer';
40// 根据密钥参数属性构造RSA非对称密钥对密钥参数
41function genRsaKeyPairSpec(nIn: bigint, eIn: bigint, dIn: bigint) {
42  let rsaCommSpec: cryptoFramework.RSACommonParamsSpec = {
43    n: nIn,
44    algName: "RSA",
45    specType: cryptoFramework.AsyKeySpecType.COMMON_PARAMS_SPEC
46  };
47  let rsaKeyPairSpec: cryptoFramework.RSAKeyPairSpec = {
48    params: rsaCommSpec,
49    sk: dIn,
50    pk: eIn,
51    algName: "RSA",
52    specType: cryptoFramework.AsyKeySpecType.KEY_PAIR_SPEC
53  };
54  return rsaKeyPairSpec;
55}
56// 生成RSA2048密钥对参数
57function genRsa2048KeyPairSpec(): cryptoFramework.RSAKeyPairSpec {
58  let nIn = BigInt("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");
59  let eIn = BigInt("0x010001");
60  let dIn = BigInt("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");
61  return genRsaKeyPairSpec(nIn, eIn, dIn);
62}
63async function rsaUseSpecDecryptOAEPPromise() {
64  let plan = "This is a test";
65  // 获得RSA密钥对密钥参数对象
66  let rsaKeyPairSpec = genRsa2048KeyPairSpec();
67  // 根据RSA密钥对参数生成RSA密钥对
68  let rsaGeneratorSpec = cryptoFramework.createAsyKeyGeneratorBySpec(rsaKeyPairSpec);
69  let cipher = cryptoFramework.createCipher("RSA|PKCS1_OAEP|SHA256|MGF1_SHA1");
70  let decoder = cryptoFramework.createCipher("RSA|PKCS1_OAEP|SHA256|MGF1_SHA1");
71  // RSA加解密PKCS1-OAEP模式填充字节流P
72  let pSource = new Uint8Array([1, 2, 3, 4]);
73  let input: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan, 'utf-8').buffer) };
74  // 生成密钥对
75  let keyPair = await rsaGeneratorSpec.generateKeyPair();
76  // 进行加密操作初始化
77  await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, keyPair.pubKey, null);
78  // get和set操作可以放在Cipher对象init之后，此处对cipher进行set和get操作
79  cipher.setCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_PSRC_UINT8ARR, pSource);
80  let retP = cipher.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_PSRC_UINT8ARR);
81  // 比较get出来的P字节流与set进去的P字节流是否一致
82  if (retP.toString() != pSource.toString()) {
83    console.error("error init pSource" + retP);
84  } else {
85    console.info("pSource changed ==" + retP);
86  }
87  // 进行OAEP其他参数的get操作
88  let md = cipher.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MD_NAME_STR);
89  console.info("md == " + md);
90  let mgf = cipher.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF_NAME_STR);
91  console.info("mgf == " + mgf);
92  let mgf1Md = cipher.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_MD_STR);
93  console.info("mgf1Md == " + mgf1Md);
94  let cipherDataBlob = await cipher.doFinal(input);
95  // get和set操作可以放在Cipher对象init之前，且与init之后等价，此处对decoder进行set和get操作
96  decoder.setCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_PSRC_UINT8ARR, pSource);
97  retP = decoder.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_PSRC_UINT8ARR);
98  // 比较get出来的P字节流与set进去的P字节流是否一致
99  if (retP.toString() != pSource.toString()) {
100    console.error("error init pSource" + retP);
101  } else {
102    console.info("pSource changed ==" + retP);
103  }
104  // 进行OAEP其他参数的get操作
105  md = decoder.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MD_NAME_STR);
106  console.info("md == " + md);
107  mgf = decoder.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF_NAME_STR);
108  console.info("mgf == " + mgf);
109  mgf1Md = decoder.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_MD_STR);
110  console.info("mgf1Md == " + mgf1Md);
111  // 初始化解密操作
112  await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, keyPair.priKey, null);
113  let decodeData = await decoder.doFinal(cipherDataBlob);
114  // 解密成功
115  if (decodeData.data.toString() === input.data.toString()) {
116    console.info("oaep decrypt success");
117  } else {
118    console.error("oaep decrypt fail");
119  }
120}
121```
122