1# Converting Binary Data into an Asymmetric Key Pair (C/C++) 2 3 4This topic uses RSA, ECC, and SM2 as an example to describe how to convert binary data into an asymmetric key pair (**OH_CryptoKeyPair**). That is, convert a piece of external or internal binary data into a **KeyPair** object for subsequent operations, such as encryption and decryption. 5 6> **NOTE** 7> 8> The asymmetric key conversion must comply with the following requirements: 9> 10> - The public key must use the ASN.1 syntax and DER encoding format and comply with X.509 specifications. 11> 12> - The private key must use the ASN.1 syntax and DER encoding format and comply with PKCS\#8 specifications. 13 14## Adding the Dynamic Library in the CMake Script 15```txt 16 target_link_libraries(entry PUBLIC libohcrypto.so) 17``` 18 19## Converting Binary Data into an RSA Key Pair 20 21For details about the algorithm specifications, see [RSA](crypto-asym-key-generation-conversion-spec.md#rsa). 22 231. Obtain the binary data of the RSA public key or private key and encapsulates the data into [Crypto_DataBlob](../../reference/apis-crypto-architecture-kit/_crypto_common_api.md#crypto_datablob). 24 25 Either the public key or private key can be passed in. In this example, the public key is passed in. 26 272. Use [OH_CryptoAsymKeyGenerator_Create](../../reference/apis-crypto-architecture-kit/_crypto_asym_key_api.md#oh_cryptoasymkeygenerator_create) with the string parameter **'RSA1024'** to create an asymmetric key generator (**OH_CryptoAsymKeyGenerator**) object for a 1024-bit RSA key with two primes. 28 29 The default number of primes for creating an RSA asymmetric key is **2**. The **PRIMES_2** parameter is omitted in the string parameter here. 30 313. Use [OH_CryptoAsymKeyGenerator_Convert](../../reference/apis-crypto-architecture-kit/_crypto_asym_key_api.md#oh_cryptoasymkeygenerator_convert) to convert the binary data into an asymmetric key pair (**OH_CryptoKeyPair**). 32 33- Example: Convert binary data into an RSA key pair. 34```c++ 35#include "CryptoArchitectureKit/crypto_common.h" 36#include "CryptoArchitectureKit/crypto_asym_key.h" 37 38static OH_Crypto_ErrCode doTestDataCovertAsymKey() 39{ 40 OH_CryptoAsymKeyGenerator *ctx = nullptr; 41 OH_Crypto_ErrCode ret; 42 43 ret = OH_CryptoAsymKeyGenerator_Create("RSA1024|PRIMES_2", &ctx); 44 if (ret != CRYPTO_SUCCESS) { 45 return ret; 46 } 47 48 uint8_t rsaDatablob[] = { 48,129,159,48,13,6,9,42,134,72,134,247,13,1,1,1,5,0,3,129,141,0, 49 48,129,137,2,129,129,0,235,184,151,247,130,216,140,187,64,124,219,137,140,184,53,137,216,105, 50 156,141,137,165,30,80,232,55,96,46,23,237,197,123,121,27,240,190,14,111,237,172,67,42,47,164, 51 226,248,211,157,213,194,131,109,181,41,173,217,127,252,121,126,26,130,55,4,134,104,73,5,132, 52 91,214,146,232,64,99,87,33,222,155,159,9,59,212,144,46,183,83,89,220,189,148,13,176,5,139,156, 53 230,143,16,152,79,36,8,112,40,174,35,83,82,57,137,87,123,215,99,199,66,131,150,31,143,56,252,2, 54 73,41,70,159,2,3,1,0,1 } 55 Crypto_DataBlob retBlob = { .data = rsaDatablob, .len = sizeof(rsaDatablob) }; 56 57 OH_CryptoKeyPair *dupKeyPair = nullptr; 58 ret = OH_CryptoAsymKeyGenerator_Convert(ctx, CRYPTO_DER, &retBlob, nullptr, &dupKeyPair); 59 if (ret != CRYPTO_SUCCESS) { 60 OH_CryptoAsymKeyGenerator_Destroy(ctx); 61 return ret; 62 } 63 64 65 OH_CryptoAsymKeyGenerator_Destroy(ctx); 66 OH_CryptoKeyPair_Destroy(dupKeyPair); 67 return ret; 68} 69``` 70 71## Converting Binary Data into an ECC Key Pair 72 73For details about the algorithm specifications, see [ECC](crypto-asym-key-generation-conversion-spec.md#ecc). 74 751. Obtain the binary data of the ECC public key or private key and encapsulates the data into [Crypto_DataBlob](../../reference/apis-crypto-architecture-kit/_crypto_common_api.md#crypto_datablob). 76 77 Either the public key or private key can be passed in. In the following example, the public key and private key are passed in separately. 78 792. Use [OH_CryptoAsymKeyGenerator_Create](../../reference/apis-crypto-architecture-kit/_crypto_asym_key_api.md#oh_cryptoasymkeygenerator_create) with the string parameter **'ECC256'** to create an asymmetric key generator (**OH_CryptoAsymKeyGenerator**) object for a 256-bit ECC key pair. 80 813. Use [OH_CryptoAsymKeyGenerator_Convert](../../reference/apis-crypto-architecture-kit/_crypto_asym_key_api.md#oh_cryptoasymkeygenerator_convert) to convert the binary data into an asymmetric key pair (**OH_CryptoKeyPair**). 82 83- Example: Convert binary data into an ECC key pair. 84```c++ 85#include "CryptoArchitectureKit/crypto_common.h" 86#include "CryptoArchitectureKit/crypto_asym_key.h" 87 88static OH_Crypto_ErrCode doAsymEccCovert() 89{ 90 OH_CryptoAsymKeyGenerator *ctx = nullptr; 91 OH_Crypto_ErrCode ret; 92 93 ret = OH_CryptoAsymKeyGenerator_Create("ECC256", &ctx); 94 if (ret != CRYPTO_SUCCESS) { 95 return ret; 96 } 97 98 uint8_t ecc224PubKeyBlobData[] = { 99 48,89,48,19,6,7,42,134,72,206,61,2,1,6,8,42,134, 72,206,61,3,1,7,3,66,0,4,157,58,248, 100 205,95,171,229,33,116,44,192,12,115,119,84,156,128,56,180,246,84,43,33,244,224,221,181, 101 154,155,222,157,124,131,217,214,134,199,155,61,196,203,107,13,227,121,57,199,109,220, 102 103,55,78,148,185,226,212,162,31,66,201,50,129,1,156 103 }; 104 105 uint8_t ecc224PriKeyBlobData[] = { 106 48,49,2,1,1,4,32,255,121,33,196,188,159,112,149,146,107,243,78,152,214,12,119,87,199, 107 207,57,116,64,150,240,121,22,88,138,196,71,70,222,160,10,6,8,42,134,72,206,61,3,1,7 108 }; 109 Crypto_DataBlob pubBlob = { .data = ecc224PubKeyBlobData, .len = sizeof(ecc224PubKeyBlobData) }; 110 Crypto_DataBlob priBlob = { .data = ecc224PriKeyBlobData, .len = sizeof(ecc224PriKeyBlobData) }; 111 112 OH_CryptoKeyPair *dupKeyPair = nullptr; 113 ret = OH_CryptoAsymKeyGenerator_Convert(ctx, CRYPTO_DER, &pubBlob, &priBlob, &dupKeyPair); 114 if (ret != CRYPTO_SUCCESS) { 115 OH_CryptoAsymKeyGenerator_Destroy(ctx); 116 return ret; 117 } 118 119 OH_CryptoAsymKeyGenerator_Destroy(ctx); 120 OH_CryptoKeyPair_Destroy(dupKeyPair); 121 return ret; 122} 123``` 124 125## Converting Binary Data into an SM2 Key Pair 126 127For details about the algorithm specifications, see [SM2](crypto-asym-key-generation-conversion-spec.md#sm2). 128 1291. Obtain the binary data of the SM2 public key or private key and encapsulate the data into [Crypto_DataBlob](../../reference/apis-crypto-architecture-kit/_crypto_common_api.md#crypto_datablob). 130 131 Either the public key or private key can be passed in. In the following example, the public key and private key are passed in separately. 132 1332. Use [OH_CryptoAsymKeyGenerator_Create](../../reference/apis-crypto-architecture-kit/_crypto_asym_key_api.md#oh_cryptoasymkeygenerator_create) with the string parameter **'SM2_256'** to create an asymmetric key generator (**OH_CryptoAsymKeyGenerator**) object for a 256-bit SM2 key pair. 134 1353. Use [OH_CryptoAsymKeyGenerator_Convert](../../reference/apis-crypto-architecture-kit/_crypto_asym_key_api.md#oh_cryptoasymkeygenerator_convert) to convert the binary data into an asymmetric key pair (**OH_CryptoKeyPair**). 136 137Example: Convert binary data into an SM2 key pair. 138```c++ 139#include "CryptoArchitectureKit/crypto_common.h" 140#include "CryptoArchitectureKit/crypto_asym_key.h" 141 142static OH_Crypto_ErrCode doAsymSm2Covert() 143{ 144 OH_CryptoAsymKeyGenerator *ctx = nullptr; 145 OH_CryptoKeyPair *dupKeyPair = nullptr; 146 OH_Crypto_ErrCode ret; 147 148 ret = OH_CryptoAsymKeyGenerator_Create("SM2_256", &ctx); 149 if (ret != CRYPTO_SUCCESS) { 150 return ret; 151 } 152 153 uint8_t sm2PubKeyBlobData[] = { 48,89,48,19,6,7,42,134,72,206,61,2,1,6,8,42,134, 154 72,206,61,3,1,7,3,66,0,4,157,58,248,205,95,171,229,33,116,44,192,12,115,119,84,156,128, 155 56,180,246,84,43,33,244,224,221,181,154,155,222,157,124,131,217,214,134,199,155,61,196, 156 203,107,13,227,121,57,199,109,220,103,55,78,148,185,226,212,162,31,66,201,50,129,1,156 }; 157 158 uint8_t sm2PriKeyBlobData[] = { 48,49,2,1,1,4,32,255,121,33,196,188,159,112,149,146, 159 107,243,78,152,214,12,119,87,199,207,57,116,64,150,240,121,22,88,138,196,71,70,222,160, 160 10,6,8,42,134,72,206,61,3,1,7 }; 161 Crypto_DataBlob pubBlob = { .data = sm2PubKeyBlobData, .len = sizeof(sm2PubKeyBlobData) }; 162 Crypto_DataBlob priBlob = { .data = sm2PriKeyBlobData, .len = sizeof(sm2PriKeyBlobData) }; 163 ret = OH_CryptoAsymKeyGenerator_Convert(ctx, CRYPTO_DER, &pubBlob, &priBlob, &dupKeyPair); 164 if (ret != CRYPTO_SUCCESS) { 165 OH_CryptoAsymKeyGenerator_Destroy(ctx); 166 return ret; 167 } 168 169 OH_CryptoAsymKeyGenerator_Destroy(ctx); 170 OH_CryptoKeyPair_Destroy(dupKeyPair); 171 return ret; 172} 173``` 174