使用RSA非对称密钥（PKCS1_OAEP模式）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：RSA。
加密
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调用cryptoFramework.createAsyKeyGeneratorBySpec、AsyKeyGeneratorBySpec.generateKeyPair，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和指定密钥参数生成密钥对理解，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。
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调用cryptoFramework.createCipher，指定字符串参数'RSA2048|PKCS1_OAEP|SHA256|MGF1_SHA1'，创建非对称密钥类型为RSA2048、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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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。
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在调用Cipher.doFinal前，调用Cipher.setCipherSpec设置PKCS1_OAEP填充参数pSource。调用Cipher.getCipherSpec可获得OAEP相关参数。
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调用Cipher.doFinal，传入明文，获取加密后的数据。
解密
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由于RSA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。
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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。PKCS1模式无加密参数，直接传入null。
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在调用Cipher.doFinal前，调用Cipher.setCipherSpec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可获得OAEP相关参数。
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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';
// 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 rsaUseSpecDecryptOAEPPromise() {
let plan = "This is a test";
// 获得RSA密钥对密钥参数对象
let rsaKeyPairSpec = genRsa2048KeyPairSpec();
// 根据RSA密钥对参数生成RSA密钥对
let rsaGeneratorSpec = cryptoFramework.createAsyKeyGeneratorBySpec(rsaKeyPairSpec);
let cipher = cryptoFramework.createCipher("RSA2048|PKCS1_OAEP|SHA256|MGF1_SHA1");
let decoder = cryptoFramework.createCipher("RSA2048|PKCS1_OAEP|SHA256|MGF1_SHA1");
// RSA加解密PKCS1-OAEP模式填充字节流P
let pSource = new Uint8Array([1, 2, 3, 4]);
let input: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(plan, 'utf-8').buffer) };
// 生成密钥对
let keyPair = await rsaGeneratorSpec.generateKeyPair();
// 进行加密操作初始化
await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, keyPair.pubKey, null);
// 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
cipher.setCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_PSRC_UINT8ARR, pSource);
let retP = cipher.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_PSRC_UINT8ARR);
// 比较get出来的P字节流与set进去的P字节流是否一致
if (retP.toString() != pSource.toString()) {
console.error("error init pSource" + retP);
} else {
console.info("pSource changed ==" + retP);
}
// 进行OAEP其他参数的get操作
let md = cipher.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MD_NAME_STR);
console.info("md == " + md);
let mgf = cipher.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF_NAME_STR);
console.info("mgf == " + mgf);
let mgf1Md = cipher.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_MD_STR);
console.info("mgf1Md == " + mgf1Md);
let cipherDataBlob = await cipher.doFinal(input);
// 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
decoder.setCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_PSRC_UINT8ARR, pSource);
retP = decoder.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_PSRC_UINT8ARR);
// 比较get出来的P字节流与set进去的P字节流是否一致
if (retP.toString() != pSource.toString()) {
console.error("error init pSource" + retP);
} else {
console.info("pSource changed ==" + retP);
}
// 进行OAEP其他参数的get操作
md = decoder.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MD_NAME_STR);
console.info("md == " + md);
mgf = decoder.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF_NAME_STR);
console.info("mgf == " + mgf);
mgf1Md = decoder.getCipherSpec(cryptoFramework.CipherSpecItem.OAEP_MGF1_MD_STR);
console.info("mgf1Md == " + mgf1Md);
// 初始化解密操作
await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, keyPair.priKey, null);
let decodeData = await decoder.doFinal(cipherDataBlob);
// 解密成功
if (decodeData.data.toString() === input.data.toString()) {
console.info("oaep decrypt success");
} else {
console.error("oaep decrypt fail");
}
}