# 使用RSA密钥对（PKCS1模式）签名验签(C/C++)

对应的算法规格请查看签名验签算法规格：RSA。

#### 在CMake脚本中链接相关动态库

```
target_link_libraries(entry PUBLIC libohcrypto.so)
```

#### 签名开发步骤

1.  调用OH\_CryptoSign\_Create，指定字符串参数'RSA1024|PKCS1|SHA256'，创建Sign实例，用于完成签名操作。
    
2.  调用OH\_CryptoSign\_Init，使用私钥（OH\_CryptoPrivKey）初始化Sign实例。
    
3.  调用OH\_CryptoSign\_Update，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。如果数据量较小，可以直接调用OH\_CryptoSign\_Final接口一次性传入。
    
4.  调用OH\_CryptoSign\_Final，获取签名后的数据。
    
5.  调用OH\_CryptoSign\_Destroy等释放内存。
    

```
#include "CryptoArchitectureKit/crypto_common.h"
#include "CryptoArchitectureKit/crypto_signature.h"
#include "CryptoArchitectureKit/crypto_asym_key.h"

static OH_Crypto_ErrCode doTestRsaSignature() {
   OH_CryptoAsymKeyGenerator *keyCtx = nullptr;
   OH_CryptoKeyPair *keyPair = nullptr;
   OH_CryptoSign *sign = nullptr;
   Crypto_DataBlob signData = {.data = nullptr, .len = 0};

   uint8_t plainText[] = {
      0x43, 0x31, 0x7d, 0xb5, 0x85, 0x2e, 0xd4, 0xef, 0x08, 0x7a, 0x17, 0x96, 0xbc, 0x7c, 0x8f, 0x80,
      0x8c, 0xa7, 0x63, 0x7f, 0x26, 0x89, 0x8f, 0xf0, 0xfa, 0xa7, 0x51, 0xbd, 0x9c, 0x69, 0x17, 0xf3,
      0xd1, 0xb5, 0xc7, 0x12, 0xbf, 0xcf, 0x91, 0x25, 0x82, 0x23, 0x6b, 0xd6, 0x64, 0x52, 0x77, 0x93,
      0x01, 0x9d, 0x70, 0xa3, 0xf4, 0x92, 0x16, 0xec, 0x3f, 0xa7, 0x3c, 0x83, 0x8d, 0x40, 0x41, 0xfc,
   }; // 待验证数据，仅供参考。
   Crypto_DataBlob msgBlob = {
      .data = reinterpret_cast<uint8_t *>(plainText),
      .len = sizeof(plainText)
   };

   OH_Crypto_ErrCode ret = OH_CryptoAsymKeyGenerator_Create((const char *)"RSA2048", &keyCtx);
   if (ret != CRYPTO_SUCCESS) {
      return ret;
   }
   ret = OH_CryptoAsymKeyGenerator_Generate(keyCtx, &keyPair);
   if (ret != CRYPTO_SUCCESS) {
      OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
      return ret;
   }

   OH_CryptoPrivKey *privKey = OH_CryptoKeyPair_GetPrivKey(keyPair);
   ret = OH_CryptoSign_Create((const char *)"RSA1024|PKCS1|SHA256", &sign);
   if (ret != CRYPTO_SUCCESS) {
      OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
      OH_CryptoKeyPair_Destroy(keyPair);
      return ret;
   }

   ret = OH_CryptoSign_Init(sign, privKey);
   if (ret != CRYPTO_SUCCESS) {
      OH_CryptoSign_Destroy(sign);
      OH_CryptoKeyPair_Destroy(keyPair);
      OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
      return ret;
   }
   ret = OH_CryptoSign_Update(sign, &msgBlob);
   if (ret != CRYPTO_SUCCESS) {
      OH_CryptoSign_Destroy(sign);
      OH_CryptoKeyPair_Destroy(keyPair);
      OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
      return ret;
   }
   ret = OH_CryptoSign_Final(sign, nullptr, &signData);
   if (ret != CRYPTO_SUCCESS) {
      OH_CryptoSign_Destroy(sign);
      OH_CryptoKeyPair_Destroy(keyPair);
      OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
      return ret;
   }

   OH_CryptoSign_Destroy(sign);
   OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
   OH_CryptoKeyPair_Destroy(keyPair);
   return CRYPTO_SUCCESS;
}
```

#### 验签开发步骤

1.  调用OH\_CryptoVerify\_Create，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OH\_CryptoVerify\_Init，使用公钥（OH\_CryptoPubKey）初始化Verify实例。
    
3.  调用OH\_CryptoVerify\_Update，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，如果数据量较小，可以直接调用OH\_CryptoVerify\_Final接口一次性传入。
    
    *   当待签名的数据较短时，可以在init完成后直接调用OH\_CryptoVerify\_Final。
    *   当数据量较大时，可以多次调用update，即分段验签。
4.  调用OH\_CryptoVerify\_Final，对数据进行验签。
    

```
#include "signing_signature_verification.h"

bool DoTestRsaSignature()
{
    OH_CryptoAsymKeyGenerator *keyCtx = nullptr;
    OH_CryptoKeyPair *keyPair = nullptr;
    OH_CryptoVerify *verify = nullptr;

    uint8_t plainText[] = {
        0x43, 0x31, 0x7d, 0xb5, 0x85, 0x2e, 0xd4, 0xef, 0x08, 0x7a, 0x17, 0x96, 0xbc, 0x7c, 0x8f, 0x80,
        0x8c, 0xa7, 0x63, 0x7f, 0x26, 0x89, 0x8f, 0xf0, 0xfa, 0xa7, 0x51, 0xbd, 0x9c, 0x69, 0x17, 0xf3,
        0xd1, 0xb5, 0xc7, 0x12, 0xbf, 0xcf, 0x91, 0x25, 0x82, 0x23, 0x6b, 0xd6, 0x64, 0x52, 0x77, 0x93,
        0x01, 0x9d, 0x70, 0xa3, 0xf4, 0x92, 0x16, 0xec, 0x3f, 0xa7, 0x3c, 0x83, 0x8d, 0x40, 0x41, 0xfc,
    };
    Crypto_DataBlob msgBlob = {.data = reinterpret_cast<uint8_t *>(plainText), .len = sizeof(plainText)};

    uint8_t pubKeyText[] = {
        0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x42, 0x45, 0x47, 0x49, 0x4e, 0x20, 0x52, 0x53, 0x41, 0x20, 0x50, 0x55, 0x42,
        0x4c, 0x49, 0x43, 0x20, 0x4b, 0x45, 0x59, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x0a, 0x4d, 0x49, 0x47, 0x4a, 0x41,
        0x6f, 0x47, 0x42, 0x41, 0x4d, 0x78, 0x63, 0x44, 0x4d, 0x6f, 0x61, 0x59, 0x52, 0x58, 0x6f, 0x78, 0x65, 0x69,
        0x33, 0x49, 0x6d, 0x33, 0x33, 0x78, 0x4a, 0x76, 0x61, 0x73, 0x63, 0x43, 0x62, 0x77, 0x31, 0x6f, 0x73, 0x63,
        0x32, 0x56, 0x56, 0x69, 0x47, 0x6a, 0x56, 0x47, 0x47, 0x4a, 0x37, 0x6c, 0x75, 0x4e, 0x41, 0x58, 0x6b, 0x6a,
        0x73, 0x56, 0x46, 0x64, 0x35, 0x0a, 0x58, 0x37, 0x4c, 0x4d, 0x6c, 0x46, 0x34, 0x63, 0x35, 0x5a, 0x75, 0x59,
        0x2f, 0x61, 0x69, 0x57, 0x77, 0x70, 0x54, 0x69, 0x63, 0x62, 0x67, 0x49, 0x33, 0x43, 0x66, 0x50, 0x6f, 0x32,
        0x6a, 0x6c, 0x52, 0x74, 0x67, 0x41, 0x46, 0x6b, 0x44, 0x71, 0x7a, 0x4b, 0x53, 0x46, 0x62, 0x46, 0x47, 0x51,
        0x6b, 0x43, 0x6e, 0x64, 0x63, 0x2b, 0x54, 0x59, 0x6b, 0x5a, 0x42, 0x32, 0x70, 0x45, 0x6f, 0x72, 0x0a, 0x7a,
        0x73, 0x61, 0x56, 0x58, 0x77, 0x5a, 0x47, 0x45, 0x34, 0x41, 0x43, 0x70, 0x59, 0x35, 0x79, 0x65, 0x66, 0x49,
        0x44, 0x6c, 0x45, 0x57, 0x49, 0x51, 0x4f, 0x6a, 0x59, 0x4b, 0x2f, 0x6c, 0x58, 0x71, 0x7a, 0x48, 0x47, 0x69,
        0x4f, 0x69, 0x32, 0x75, 0x4a, 0x45, 0x75, 0x44, 0x43, 0x50, 0x6a, 0x51, 0x64, 0x6a, 0x54, 0x41, 0x67, 0x4d,
        0x42, 0x41, 0x41, 0x45, 0x3d, 0x0a, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x45, 0x4e, 0x44, 0x20, 0x52, 0x53, 0x41,
        0x20, 0x50, 0x55, 0x42, 0x4c, 0x49, 0x43, 0x20, 0x4b, 0x45, 0x59, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x0a,
    };

    Crypto_DataBlob keyBlob = {.data = reinterpret_cast<uint8_t *>(pubKeyText), .len = sizeof(pubKeyText)};

    uint8_t signText[] = {
        0x68, 0x2f, 0x3b, 0xe6, 0xa6, 0x5c, 0xb8, 0x60, 0xd4, 0xe1, 0x64, 0xa7, 0xd8, 0x0c, 0x9c, 0x89,
        0x39, 0xb4, 0xf0, 0xb7, 0xad, 0xb5, 0x8a, 0x71, 0x04, 0xf1, 0xa5, 0x63, 0xdd, 0x32, 0x6a, 0x44,
        0xeb, 0xff, 0xb7, 0xe6, 0x85, 0xe5, 0xa5, 0x55, 0x5d, 0x5b, 0x28, 0x53, 0x63, 0xe4, 0xb3, 0xb9,
        0xa8, 0x70, 0xc8, 0x8f, 0xcd, 0x21, 0x8d, 0xe6, 0x1f, 0xe5, 0x78, 0x34, 0xd3, 0x45, 0x0c, 0x9c,
        0x7a, 0x22, 0x1b, 0x63, 0x55, 0xca, 0x14, 0xa5, 0x0c, 0x7a, 0x40, 0x8e, 0xa1, 0x14, 0x78, 0xa1,
        0xf1, 0x36, 0x78, 0xbd, 0xba, 0x37, 0x3b, 0x5b, 0xb0, 0x8e, 0xb3, 0x4a, 0x9b, 0x1b, 0x0c, 0xfa,
        0xfa, 0xc7, 0x9f, 0xb1, 0x35, 0x48, 0x82, 0x73, 0xf8, 0x6b, 0xd4, 0x76, 0x33, 0x5c, 0xed, 0x9c,
        0xd8, 0x4b, 0xc9, 0x92, 0xa0, 0x3f, 0x6e, 0xba, 0x78, 0x2e, 0x80, 0x78, 0x1e, 0x74, 0xa0, 0x47,
    };

    Crypto_DataBlob signBlob = {.data = reinterpret_cast<uint8_t *>(signText), .len = sizeof(signText)};

    // keypair
    OH_Crypto_ErrCode ret = CRYPTO_SUCCESS;
    ret = OH_CryptoAsymKeyGenerator_Create((const char *)"RSA2048", &keyCtx);
    if (ret != CRYPTO_SUCCESS) {
        return false;
    }
    ret = OH_CryptoAsymKeyGenerator_Convert(keyCtx, CRYPTO_PEM, &keyBlob, nullptr, &keyPair);
    if (ret != CRYPTO_SUCCESS) {
        OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
        return false;
    }
    OH_CryptoPubKey *pubKey = OH_CryptoKeyPair_GetPubKey(keyPair);
    // verify
    ret = OH_CryptoVerify_Create((const char *)"RSA1024|PKCS1|SHA256", &verify);
    if (ret != CRYPTO_SUCCESS) {
        OH_CryptoVerify_Destroy(verify);
        OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
        return false;
    }
    ret = OH_CryptoVerify_Init(verify, pubKey);
    if (ret != CRYPTO_SUCCESS) {
        OH_CryptoVerify_Destroy(verify);
        OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
        return false;
    }
    bool res = OH_CryptoVerify_Final(verify, &msgBlob, &signBlob);
    if (res != true) {
        OH_CryptoVerify_Destroy(verify);
        OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
        return false;
    }

    OH_CryptoVerify_Destroy(verify);
    OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
    OH_CryptoKeyPair_Destroy(keyPair);
    return res;
}
```