1# 使用RSA密钥对分段验签(PKCS1模式)(C/C++)
2
3
4对应的算法规格请查看[验签算法规格:RSA](crypto-sign-sig-verify-overview.md#rsa)。
5
6
7## 在CMake脚本中链接相关动态库
8```txt
9   target_link_libraries(entry PUBLIC libohcrypto.so)
10```
11
12## 开发步骤
13
14
151. 调用[OH_CryptoVerify_Create](../../reference/apis-crypto-architecture-kit/_crypto_signature_api.md#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。
16
172. 调用[OH_CryptoVerify_Init](../../reference/apis-crypto-architecture-kit/_crypto_signature_api.md#oh_cryptoverify_init),使用公钥(OH_CryptoPubKey)初始化Verify实例。
18
193. 调用[OH_CryptoVerify_Update](../../reference/apis-crypto-architecture-kit/_crypto_signature_api.md#oh_cryptoverify_update),传入待验证的数据。
20   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。
21
224. 调用[OH_CryptoVerify_Final](../../reference/apis-crypto-architecture-kit/_crypto_signature_api.md#oh_cryptoverify_final),对数据进行验签。
23
24
25- 示例:
26
27```c++
28#include "CryptoArchitectureKit/crypto_common.h"
29#include "CryptoArchitectureKit/crypto_asym_key.h"
30
31static bool doTestRsaSignatureSeg()
32{
33   OH_CryptoAsymKeyGenerator *keyCtx = nullptr;
34   OH_CryptoKeyPair *keyPair = nullptr;
35   OH_CryptoVerify *verify = nullptr;
36
37   uint8_t plainText[] = {
38      0x43, 0x31, 0x7d, 0xb5, 0x85, 0x2e, 0xd4, 0xef, 0x08, 0x7a, 0x17, 0x96, 0xbc, 0x7c, 0x8f, 0x80,
39      0x8c, 0xa7, 0x63, 0x7f, 0x26, 0x89, 0x8f, 0xf0, 0xfa, 0xa7, 0x51, 0xbd, 0x9c, 0x69, 0x17, 0xf3,
40      0xd1, 0xb5, 0xc7, 0x12, 0xbf, 0xcf, 0x91, 0x25, 0x82, 0x23, 0x6b, 0xd6, 0x64, 0x52, 0x77, 0x93,
41      0x01, 0x9d, 0x70, 0xa3, 0xf4, 0x92, 0x16, 0xec, 0x3f, 0xa7, 0x3c, 0x83, 0x8d, 0x40, 0x41, 0xfc,
42   };
43   Crypto_DataBlob msgBlob = {
44      .data = reinterpret_cast<uint8_t *>(plainText),
45      .len = sizeof(plainText)
46   };
47
48   uint8_t pubKeyText[] = {
49      0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x42, 0x45, 0x47, 0x49, 0x4e, 0x20, 0x52, 0x53, 0x41, 0x20, 0x50,
50      0x55, 0x42, 0x4c, 0x49, 0x43, 0x20, 0x4b, 0x45, 0x59, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x0a, 0x4d,
51      0x49, 0x47, 0x4a, 0x41, 0x6f, 0x47, 0x42, 0x41, 0x4d, 0x78, 0x63, 0x44, 0x4d, 0x6f, 0x61, 0x59,
52      0x52, 0x58, 0x6f, 0x78, 0x65, 0x69, 0x33, 0x49, 0x6d, 0x33, 0x33, 0x78, 0x4a, 0x76, 0x61, 0x73,
53      0x63, 0x43, 0x62, 0x77, 0x31, 0x6f, 0x73, 0x63, 0x32, 0x56, 0x56, 0x69, 0x47, 0x6a, 0x56, 0x47,
54      0x47, 0x4a, 0x37, 0x6c, 0x75, 0x4e, 0x41, 0x58, 0x6b, 0x6a, 0x73, 0x56, 0x46, 0x64, 0x35, 0x0a,
55      0x58, 0x37, 0x4c, 0x4d, 0x6c, 0x46, 0x34, 0x63, 0x35, 0x5a, 0x75, 0x59, 0x2f, 0x61, 0x69, 0x57,
56      0x77, 0x70, 0x54, 0x69, 0x63, 0x62, 0x67, 0x49, 0x33, 0x43, 0x66, 0x50, 0x6f, 0x32, 0x6a, 0x6c,
57      0x52, 0x74, 0x67, 0x41, 0x46, 0x6b, 0x44, 0x71, 0x7a, 0x4b, 0x53, 0x46, 0x62, 0x46, 0x47, 0x51,
58      0x6b, 0x43, 0x6e, 0x64, 0x63, 0x2b, 0x54, 0x59, 0x6b, 0x5a, 0x42, 0x32, 0x70, 0x45, 0x6f, 0x72,
59      0x0a, 0x7a, 0x73, 0x61, 0x56, 0x58, 0x77, 0x5a, 0x47, 0x45, 0x34, 0x41, 0x43, 0x70, 0x59, 0x35,
60      0x79, 0x65, 0x66, 0x49, 0x44, 0x6c, 0x45, 0x57, 0x49, 0x51, 0x4f, 0x6a, 0x59, 0x4b, 0x2f, 0x6c,
61      0x58, 0x71, 0x7a, 0x48, 0x47, 0x69, 0x4f, 0x69, 0x32, 0x75, 0x4a, 0x45, 0x75, 0x44, 0x43, 0x50,
62      0x6a, 0x51, 0x64, 0x6a, 0x54, 0x41, 0x67, 0x4d, 0x42, 0x41, 0x41, 0x45, 0x3d, 0x0a, 0x2d, 0x2d,
63      0x2d, 0x2d, 0x2d, 0x45, 0x4e, 0x44, 0x20, 0x52, 0x53, 0x41, 0x20, 0x50, 0x55, 0x42, 0x4c, 0x49,
64      0x43, 0x20, 0x4b, 0x45, 0x59, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x0a,
65   };
66
67   Crypto_DataBlob keyBlob = {
68      .data = reinterpret_cast<uint8_t *>(pubKeyText),
69      .len = sizeof(pubKeyText)
70   };
71
72   uint8_t signText[] = {
73      0x68, 0x2f, 0x3b, 0xe6, 0xa6, 0x5c, 0xb8, 0x60, 0xd4, 0xe1, 0x64, 0xa7, 0xd8, 0x0c, 0x9c, 0x89,
74      0x39, 0xb4, 0xf0, 0xb7, 0xad, 0xb5, 0x8a, 0x71, 0x04, 0xf1, 0xa5, 0x63, 0xdd, 0x32, 0x6a, 0x44,
75      0xeb, 0xff, 0xb7, 0xe6, 0x85, 0xe5, 0xa5, 0x55, 0x5d, 0x5b, 0x28, 0x53, 0x63, 0xe4, 0xb3, 0xb9,
76      0xa8, 0x70, 0xc8, 0x8f, 0xcd, 0x21, 0x8d, 0xe6, 0x1f, 0xe5, 0x78, 0x34, 0xd3, 0x45, 0x0c, 0x9c,
77      0x7a, 0x22, 0x1b, 0x63, 0x55, 0xca, 0x14, 0xa5, 0x0c, 0x7a, 0x40, 0x8e, 0xa1, 0x14, 0x78, 0xa1,
78      0xf1, 0x36, 0x78, 0xbd, 0xba, 0x37, 0x3b, 0x5b, 0xb0, 0x8e, 0xb3, 0x4a, 0x9b, 0x1b, 0x0c, 0xfa,
79      0xfa, 0xc7, 0x9f, 0xb1, 0x35, 0x48, 0x82, 0x73, 0xf8, 0x6b, 0xd4, 0x76, 0x33, 0x5c, 0xed, 0x9c,
80      0xd8, 0x4b, 0xc9, 0x92, 0xa0, 0x3f, 0x6e, 0xba, 0x78, 0x2e, 0x80, 0x78, 0x1e, 0x74, 0xa0, 0x47,
81   };
82
83   Crypto_DataBlob signBlob = {
84      .data = reinterpret_cast<uint8_t *>(signText),
85      .len = sizeof(signText)
86   };
87
88   // keypair
89   OH_Crypto_ErrCode ret = CRYPTO_SUCCESS;
90   ret = OH_CryptoAsymKeyGenerator_Create((const char *)"RSA2048", &keyCtx);
91   if (ret != CRYPTO_SUCCESS) {
92      return false;
93   }
94   ret = OH_CryptoAsymKeyGenerator_Convert(keyCtx, CRYPTO_PEM, &keyBlob, nullptr, &keyPair);
95   if (ret != CRYPTO_SUCCESS) {
96      OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
97      return false;
98   }
99   OH_CryptoPubKey *pubKey = OH_CryptoKeyPair_GetPubKey(keyPair);
100   // verify
101   ret = OH_CryptoVerify_Create((const char *)"RSA1024|PKCS1|SHA256", &verify);
102   if (ret != CRYPTO_SUCCESS) {
103      OH_CryptoVerify_Destroy(verify);
104      OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
105      return false;
106   }
107   int blockSize = 20;
108   int cnt_s = 64 / blockSize;
109   int rem_s = 64 % blockSize;
110   ret = OH_CryptoVerify_Init(verify, pubKey);
111   if (ret != CRYPTO_SUCCESS) {
112      OH_CryptoVerify_Destroy(verify);
113      OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
114      return false;
115   }
116   for (int i = 0; i < cnt_s; i++) {
117      msgBlob.len = blockSize;
118      ret = OH_CryptoVerify_Update(verify, (Crypto_DataBlob *)&msgBlob);
119      if (ret != CRYPTO_SUCCESS) {
120         OH_CryptoVerify_Destroy(verify);
121         OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
122         return false;
123      }
124      msgBlob.data += blockSize;
125   }
126   bool res = false;
127   if (rem_s > 0) {
128      msgBlob.len = rem_s;
129      res = OH_CryptoVerify_Final(verify, (Crypto_DataBlob *)&msgBlob, (Crypto_DataBlob *)&signBlob);
130      if (res != true) {
131         OH_CryptoVerify_Destroy(verify);
132         OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
133         return false;
134      }
135   }
136
137   msgBlob.data -=  64 - rem_s;
138   msgBlob.len = 64;
139
140   OH_CryptoVerify_Destroy(verify);
141   OH_CryptoAsymKeyGenerator_Destroy(keyCtx);
142   OH_CryptoKeyPair_Destroy(keyPair);
143   return res;
144}
145```
146