1# Signature Recovery Using an RSA Key Pair (PKCS1 Mode) (C/C++) 2 3<!--Kit: Crypto Architecture Kit--> 4<!--Subsystem: Security--> 5<!--Owner: @zxz--3--> 6<!--Designer: @lanming--> 7<!--Tester: @PAFT--> 8<!--Adviser: @zengyawen--> 9 10For details about the algorithm specifications, see [RSA](crypto-sign-sig-verify-overview.md#rsa). 11 12## Adding the Dynamic Library in the CMake Script 13```txt 14target_link_libraries(entry PUBLIC libohcrypto.so) 15``` 16 17## How to Develop 18 191. Call [OH_CryptoVerify_Create](../../reference/apis-crypto-architecture-kit/capi-crypto-signature-h.md#oh_cryptoverify_create) with the string parameter **'RSA1024|PKCS1|SHA256|Recover'** to create a **Verify** instance. The key parameters must be the same as that used to create the **Sign** instance. 20 212. Call [OH_CryptoVerify_Init](../../reference/apis-crypto-architecture-kit/capi-crypto-signature-h.md#oh_cryptoverify_init) to initialize the **Verify** instance by using the public key (**OH_CryptoPubKey**). 22 233. Call [OH_CryptoVerify_Recover](../../reference/apis-crypto-architecture-kit/capi-crypto-signature-h.md#oh_cryptoverify_recover) to restore the data. 24 25```c++ 26#include "CryptoArchitectureKit/crypto_common.h" 27#include "CryptoArchitectureKit/crypto_signature.h" 28#include "CryptoArchitectureKit/crypto_asym_key.h" 29 30static OH_Crypto_ErrCode doTestRsaSignatureRecover() 31{ 32 OH_CryptoAsymKeyGenerator *keyCtx = nullptr; 33 OH_CryptoKeyPair *keyPair = nullptr; 34 OH_CryptoVerify *verify = nullptr; 35 36 uint8_t plainText[] = { 37 0xc4, 0xa5, 0xe5, 0x45, 0xee, 0x71, 0x5e, 0x3b, 0x24, 0x1d, 0x7e, 0x62, 0xd6, 0x6b, 0xab, 0x98, 38 0x88, 0x0f, 0xaf, 0x1e, 0x96, 0xa0, 0x6c, 0xa5, 0x0d, 0x29, 0xfd, 0xcc, 0xef, 0xf6, 0x2b, 0x92 39 }; 40 Crypto_DataBlob msgBlob = { 41 .data = reinterpret_cast<uint8_t *>(plainText), 42 .len = sizeof(plainText) 43 }; 44 45 uint8_t pubKeyText[] = { 46 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x42, 0x45, 0x47, 0x49, 0x4e, 0x20, 0x52, 0x53, 0x41, 0x20, 0x50, 47 0x55, 0x42, 0x4c, 0x49, 0x43, 0x20, 0x4b, 0x45, 0x59, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x0a, 0x4d, 48 0x49, 0x47, 0x4a, 0x41, 0x6f, 0x47, 0x42, 0x41, 0x4b, 0x72, 0x55, 0x74, 0x74, 0x64, 0x76, 0x73, 49 0x2b, 0x62, 0x6e, 0x4d, 0x2f, 0x6f, 0x4e, 0x75, 0x39, 0x45, 0x42, 0x78, 0x35, 0x64, 0x49, 0x6d, 50 0x61, 0x70, 0x52, 0x67, 0x4d, 0x6a, 0x4b, 0x41, 0x38, 0x51, 0x48, 0x4b, 0x61, 0x75, 0x2f, 0x6c, 51 0x58, 0x50, 0x50, 0x68, 0x76, 0x38, 0x30, 0x69, 0x59, 0x4c, 0x46, 0x2b, 0x79, 0x35, 0x35, 0x0a, 52 0x6d, 0x42, 0x2f, 0x38, 0x2b, 0x4b, 0x68, 0x34, 0x34, 0x43, 0x2b, 0x5a, 0x76, 0x6f, 0x78, 0x5a, 53 0x66, 0x38, 0x78, 0x34, 0x6e, 0x78, 0x6f, 0x71, 0x76, 0x4f, 0x6f, 0x73, 0x32, 0x44, 0x55, 0x69, 54 0x51, 0x44, 0x4f, 0x4a, 0x35, 0x63, 0x57, 0x68, 0x5a, 0x62, 0x4d, 0x71, 0x4d, 0x42, 0x71, 0x62, 55 0x39, 0x30, 0x4e, 0x39, 0x63, 0x2f, 0x44, 0x51, 0x67, 0x39, 0x34, 0x63, 0x52, 0x7a, 0x35, 0x66, 56 0x0a, 0x68, 0x55, 0x66, 0x6d, 0x66, 0x6d, 0x54, 0x41, 0x46, 0x6a, 0x5a, 0x53, 0x33, 0x78, 0x6c, 57 0x78, 0x77, 0x6e, 0x50, 0x77, 0x66, 0x66, 0x39, 0x71, 0x44, 0x79, 0x4c, 0x63, 0x5a, 0x55, 0x6b, 58 0x6e, 0x64, 0x43, 0x30, 0x50, 0x77, 0x72, 0x6c, 0x38, 0x72, 0x70, 0x4b, 0x7a, 0x50, 0x47, 0x63, 59 0x71, 0x4e, 0x67, 0x33, 0x5a, 0x41, 0x67, 0x4d, 0x42, 0x41, 0x41, 0x45, 0x3d, 0x0a, 0x2d, 0x2d, 60 0x2d, 0x2d, 0x2d, 0x45, 0x4e, 0x44, 0x20, 0x52, 0x53, 0x41, 0x20, 0x50, 0x55, 0x42, 0x4c, 0x49, 61 0x43, 0x20, 0x4b, 0x45, 0x59, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x0a, 62 }; 63 64 Crypto_DataBlob keyBlob = { 65 .data = reinterpret_cast<uint8_t *>(pubKeyText), 66 .len = sizeof(pubKeyText) 67 }; 68 69 uint8_t signText[] = { 70 0x1f, 0xe3, 0xcf, 0x8d, 0x94, 0xb4, 0xa0, 0x9e, 0xf1, 0x0c, 0x38, 0x59, 0xcb, 0x5b, 0x89, 0xc9, 71 0x66, 0x8b, 0xfd, 0x8d, 0x1e, 0x37, 0xfa, 0x5e, 0x1b, 0xb1, 0x51, 0x07, 0xf1, 0xb0, 0x7d, 0x18, 72 0x2d, 0x82, 0x2a, 0x04, 0xa4, 0x4e, 0x94, 0x7e, 0x76, 0xb8, 0xa4, 0x78, 0x90, 0x2f, 0x43, 0x1d, 73 0x95, 0x80, 0xd7, 0xb3, 0x46, 0x4d, 0x58, 0x4b, 0xcd, 0x1f, 0x1d, 0xb3, 0x1f, 0x6b, 0x15, 0xd8, 74 0x33, 0x51, 0x1d, 0x36, 0x12, 0x39, 0x92, 0xb4, 0x4d, 0xe2, 0x89, 0x26, 0x01, 0xe9, 0x1f, 0xc0, 75 0x9c, 0x7c, 0xd8, 0xeb, 0x47, 0xff, 0xfb, 0x5d, 0x98, 0x9a, 0x02, 0x6a, 0x16, 0x37, 0xb1, 0xf5, 76 0x08, 0x4d, 0xd7, 0xa0, 0xf2, 0x9e, 0xbe, 0x4b, 0x54, 0x77, 0x94, 0x95, 0x4b, 0x97, 0x10, 0x22, 77 0x49, 0xa5, 0x2e, 0x05, 0x86, 0xfd, 0x6f, 0x9a, 0x40, 0xe6, 0x43, 0xab, 0xc5, 0xbc, 0xac, 0x21, 78 }; 79 80 Crypto_DataBlob signBlob = { 81 .data = reinterpret_cast<uint8_t *>(signText), 82 .len = sizeof(signText) 83 }; 84 85 // Key pair 86 OH_Crypto_ErrCode ret = CRYPTO_SUCCESS; 87 ret = OH_CryptoAsymKeyGenerator_Create((const char *)"RSA2048", &keyCtx); 88 if (ret != CRYPTO_SUCCESS) { 89 return ret; 90 } 91 ret = OH_CryptoAsymKeyGenerator_Convert(keyCtx, CRYPTO_PEM, &keyBlob, nullptr, &keyPair); 92 if (ret != CRYPTO_SUCCESS) { 93 OH_CryptoAsymKeyGenerator_Destroy(keyCtx); 94 return ret; 95 } 96 OH_CryptoPubKey *pubKey = OH_CryptoKeyPair_GetPubKey(keyPair); 97 // verify 98 ret = OH_CryptoVerify_Create((const char *)"RSA1024|PKCS1|SHA256|Recover", &verify); 99 if (ret != CRYPTO_SUCCESS) { 100 OH_CryptoVerify_Destroy(verify); 101 OH_CryptoAsymKeyGenerator_Destroy(keyCtx); 102 return ret; 103 } 104 ret = OH_CryptoVerify_Init(verify, pubKey); 105 if (ret != CRYPTO_SUCCESS) { 106 OH_CryptoVerify_Destroy(verify); 107 OH_CryptoAsymKeyGenerator_Destroy(keyCtx); 108 return ret; 109 } 110 Crypto_DataBlob rawSignData = {.data = nullptr, .len = 0}; 111 ret = OH_CryptoVerify_Recover(verify, (Crypto_DataBlob *)&signBlob, &rawSignData); 112 if (ret != CRYPTO_SUCCESS) { 113 OH_CryptoVerify_Destroy(verify); 114 OH_CryptoAsymKeyGenerator_Destroy(keyCtx); 115 return ret; 116 } 117 118 OH_CryptoVerify_Destroy(verify); 119 OH_CryptoAsymKeyGenerator_Destroy(keyCtx); 120 OH_CryptoKeyPair_Destroy(keyPair); 121 return ret; 122} 123``` 124