1# 加解密(C/C++)
2
3
4以AES 256密钥为例，完成加解密。具体的场景介绍及支持的算法规格，请参考[密钥生成支持的算法](huks-key-generation-overview.md#支持的算法)。
5
6## 在CMake脚本中链接相关动态库
7```txt
8   target_link_libraries(entry PUBLIC libhuks_ndk.z.so)
9```
10
11## 开发步骤
12
13**生成密钥**
14
151. 指定密钥别名。
16
172. 初始化密钥属性集。
18
193. 调用[OH_Huks_GenerateKeyItem](../../reference/apis-universal-keystore-kit/_huks_key_api.md#oh_huks_generatekeyitem)生成密钥，具体请参考[密钥生成](huks-key-generation-overview.md)。
20
21除此之外，开发者也可以参考[密钥导入](huks-key-import-overview.md)，导入已有的密钥。
22
23**加密**
24
251. 获取密钥别名。
26
272. 获取待加密的数据。
28
293. 调用[OH_Huks_InitParamSet](../../reference/apis-universal-keystore-kit/_huks_param_set_api.md#oh_huks_initparamset)指定算法参数配置。
30   在下方示例中，使用算法AES进行加密时，必须要选择其对应分组模式以及填充模式，用例中选取的分组模式为CBC、填充模式为PKCS7，此时必须要填参数IV。
31
324. 调用[OH_Huks_InitSession](../../reference/apis-universal-keystore-kit/_huks_key_api.md#oh_huks_initsession)初始化密钥会话，并获取会话的句柄handle。
33
345. 调用[OH_Huks_FinishSession](../../reference/apis-universal-keystore-kit/_huks_key_api.md#oh_huks_finishsession)结束密钥会话，获取加密后的密文。
35
36**解密**
37
381. 获取密钥别名。
39
402. 获取待解密的密文。
41
423. 调用[OH_Huks_InitParamSet](../../reference/apis-universal-keystore-kit/_huks_param_set_api.md#oh_huks_initparamset)指定算法参数配置。
43   在下方示例中，使用算法AES进行解密时，必须要选择其对应分组模式以及填充模式，用例中选取的分组模式为CBC、填充模式为PKCS7，此时必须要填参数IV。
44
454. 调用[OH_Huks_InitSession](../../reference/apis-universal-keystore-kit/_huks_key_api.md#oh_huks_initsession)初始化密钥会话，并获取会话的句柄handle。
46
475. 调用[OH_Huks_FinishSession](../../reference/apis-universal-keystore-kit/_huks_key_api.md#oh_huks_finishsession)结束密钥会话，获取解密后的数据。
48
49**删除密钥**
50
51当密钥废弃不用时，需要调用OH_Huks_DeleteKeyItem删除密钥，具体请参考[密钥删除](huks-delete-key-ndk.md)。
52
53```c++
54#include "huks/native_huks_api.h"
55#include "huks/native_huks_param.h"
56#include <string.h>
57OH_Huks_Result InitParamSet(
58    struct OH_Huks_ParamSet **paramSet,
59    const struct OH_Huks_Param *params,
60    uint32_t paramCount)
61{
62    OH_Huks_Result ret = OH_Huks_InitParamSet(paramSet);
63    if (ret.errorCode != OH_HUKS_SUCCESS) {
64        return ret;
65    }
66    ret = OH_Huks_AddParams(*paramSet, params, paramCount);
67    if (ret.errorCode != OH_HUKS_SUCCESS) {
68        OH_Huks_FreeParamSet(paramSet);
69        return ret;
70    }
71    ret = OH_Huks_BuildParamSet(paramSet);
72    if (ret.errorCode != OH_HUKS_SUCCESS) {
73        OH_Huks_FreeParamSet(paramSet);
74        return ret;
75    }
76    return ret;
77}
78static const uint32_t IV_SIZE = 16;
79static uint8_t IV[IV_SIZE] = { 0 }; // this is a test value, for real use the iv should be different every time
80static struct OH_Huks_Param g_genEncDecParams[] = {
81    {
82        .tag = OH_HUKS_TAG_ALGORITHM,
83        .uint32Param = OH_HUKS_ALG_AES
84    }, {
85        .tag = OH_HUKS_TAG_PURPOSE,
86        .uint32Param = OH_HUKS_KEY_PURPOSE_ENCRYPT | OH_HUKS_KEY_PURPOSE_DECRYPT
87    }, {
88        .tag = OH_HUKS_TAG_KEY_SIZE,
89        .uint32Param = OH_HUKS_AES_KEY_SIZE_256
90    }, {
91        .tag = OH_HUKS_TAG_PADDING,
92        .uint32Param = OH_HUKS_PADDING_NONE
93    }, {
94        .tag = OH_HUKS_TAG_BLOCK_MODE,
95        .uint32Param = OH_HUKS_MODE_CBC
96    }
97};
98static struct OH_Huks_Param g_encryptParams[] = {
99    {
100        .tag = OH_HUKS_TAG_ALGORITHM,
101        .uint32Param = OH_HUKS_ALG_AES
102    }, {
103        .tag = OH_HUKS_TAG_PURPOSE,
104        .uint32Param = OH_HUKS_KEY_PURPOSE_ENCRYPT
105    }, {
106        .tag = OH_HUKS_TAG_KEY_SIZE,
107        .uint32Param = OH_HUKS_AES_KEY_SIZE_256
108    }, {
109        .tag = OH_HUKS_TAG_PADDING,
110        .uint32Param = OH_HUKS_PADDING_NONE
111    }, {
112        .tag = OH_HUKS_TAG_BLOCK_MODE,
113        .uint32Param = OH_HUKS_MODE_CBC
114    }, {
115        .tag = OH_HUKS_TAG_IV,
116        .blob = {
117            .size = IV_SIZE,
118            .data = (uint8_t *)IV // this is a test value, for real use the iv should be different every time
119        }
120    }
121};
122static struct OH_Huks_Param g_decryptParams[] = {
123    {
124        .tag = OH_HUKS_TAG_ALGORITHM,
125        .uint32Param = OH_HUKS_ALG_AES
126    }, {
127        .tag = OH_HUKS_TAG_PURPOSE,
128        .uint32Param = OH_HUKS_KEY_PURPOSE_DECRYPT
129    }, {
130        .tag = OH_HUKS_TAG_KEY_SIZE,
131        .uint32Param = OH_HUKS_AES_KEY_SIZE_256
132    }, {
133        .tag = OH_HUKS_TAG_PADDING,
134        .uint32Param = OH_HUKS_PADDING_NONE
135    }, {
136        .tag = OH_HUKS_TAG_BLOCK_MODE,
137        .uint32Param = OH_HUKS_MODE_CBC
138    }, {
139        .tag = OH_HUKS_TAG_IV,
140        .blob = {
141            .size = IV_SIZE,
142            .data = (uint8_t *)IV // this is a test value, for real use the iv should be different every time
143        }
144    }
145};
146static const uint32_t AES_COMMON_SIZE = 1024;
147OH_Huks_Result HksAesCipherTestEncrypt(
148        const struct OH_Huks_Blob *keyAlias,
149        const struct OH_Huks_ParamSet *encryptParamSet, const struct OH_Huks_Blob *inData, struct OH_Huks_Blob *cipherText)
150{
151    uint8_t handleE[sizeof(uint64_t)] = {0};
152    struct OH_Huks_Blob handleEncrypt = {sizeof(uint64_t), handleE};
153    OH_Huks_Result ret = OH_Huks_InitSession(keyAlias, encryptParamSet, &handleEncrypt, nullptr);
154    if (ret.errorCode != OH_HUKS_SUCCESS) {
155        return ret;
156    }
157    ret = OH_Huks_FinishSession(&handleEncrypt, encryptParamSet, inData, cipherText);
158    return ret;
159}
160OH_Huks_Result HksAesCipherTestDecrypt(
161    const struct OH_Huks_Blob *keyAlias,
162    const struct OH_Huks_ParamSet *decryptParamSet, const struct OH_Huks_Blob *cipherText, struct OH_Huks_Blob *plainText,
163    const struct OH_Huks_Blob *inData)
164{
165    uint8_t handleD[sizeof(uint64_t)] = {0};
166    struct OH_Huks_Blob handleDecrypt = {sizeof(uint64_t), handleD};
167    OH_Huks_Result ret = OH_Huks_InitSession(keyAlias, decryptParamSet, &handleDecrypt, nullptr);
168    if (ret.errorCode != OH_HUKS_SUCCESS) {
169        return ret;
170    }
171    ret = OH_Huks_FinishSession(&handleDecrypt, decryptParamSet, cipherText, plainText);
172    return ret;
173}
174static napi_value EncDecKey(napi_env env, napi_callback_info info)
175{
176    char tmpKeyAlias[] = "test_enc_dec";
177    struct OH_Huks_Blob keyAlias = { (uint32_t)strlen(tmpKeyAlias), (uint8_t *)tmpKeyAlias };
178    struct OH_Huks_ParamSet *genParamSet = nullptr;
179    struct OH_Huks_ParamSet *encryptParamSet = nullptr;
180    struct OH_Huks_ParamSet *decryptParamSet = nullptr;
181    OH_Huks_Result ohResult;
182    do {
183        /* 1. Generate Key */
184        /*
185        * 模拟生成密钥场景
186        * 1.1. 确定密钥别名
187        */
188        /*
189        * 1.2. 获取生成密钥算法参数配置
190        */
191        ohResult = InitParamSet(&genParamSet, g_genEncDecParams, sizeof(g_genEncDecParams) / sizeof(OH_Huks_Param));
192        if (ohResult.errorCode != OH_HUKS_SUCCESS) {
193            break;
194        }
195        /*
196        * 1.3. 调用generateKeyItem
197        */
198        ohResult = OH_Huks_GenerateKeyItem(&keyAlias, genParamSet, nullptr);
199        if (ohResult.errorCode != OH_HUKS_SUCCESS) {
200            break;
201        }
202        /* 2. Encrypt */
203        /*
204        * 模拟加密场景
205        * 2.1. 获取密钥别名
206        */
207        /*
208        * 2.2. 获取待加密的数据
209        */
210        /*
211        * 2.3. 获取加密算法参数配置
212        */
213        ohResult = InitParamSet(&encryptParamSet, g_encryptParams, sizeof(g_encryptParams) / sizeof(OH_Huks_Param));
214        if (ohResult.errorCode != OH_HUKS_SUCCESS) {
215            break;
216        }
217        char tmpInData[] = "AES_ECB_INDATA_1";
218        struct OH_Huks_Blob inData = { (uint32_t)strlen(tmpInData), (uint8_t *)tmpInData };
219        uint8_t cipher[AES_COMMON_SIZE] = {0};
220        struct OH_Huks_Blob cipherText = {AES_COMMON_SIZE, cipher};
221        /*
222        * 2.4. 调用initSession获取handle
223        */
224        /*
225        * 2.5. 调用finishSession获取加密后的密文
226        */
227        ohResult = HksAesCipherTestEncrypt(&keyAlias, encryptParamSet, &inData, &cipherText);
228        if (ohResult.errorCode != OH_HUKS_SUCCESS) {
229            break;
230        }
231        /* 3. Decrypt */
232        /*
233        * 模拟解密场景
234        * 3.1. 获取密钥别名
235        */
236        /*
237        * 3.2. 获取待解密的密文
238        */
239        /*
240        * 3.3. 获取解密算法参数配置
241        */
242        ohResult = InitParamSet(&decryptParamSet, g_decryptParams, sizeof(g_decryptParams) / sizeof(OH_Huks_Param));
243        if (ohResult.errorCode != OH_HUKS_SUCCESS) {
244            break;
245        }
246        uint8_t plain[AES_COMMON_SIZE] = {0};
247        struct OH_Huks_Blob plainText = {AES_COMMON_SIZE, plain};
248        /*
249        * 3.4. 调用initSession获取handle
250        */
251        /*
252        * 3.5. 调用finishSession获取解密后的数据
253        */
254        ohResult = HksAesCipherTestDecrypt(&keyAlias, decryptParamSet, &cipherText, &plainText, &inData);
255    } while (0);
256    /* 4. Delete Key */
257    /*
258    * 模拟删除密钥场景
259    * 4.1. 获取密钥别名
260    */
261    /*
262    * 4.2. 调用deleteKeyItem删除密钥
263    */
264    (void)OH_Huks_DeleteKeyItem(&keyAlias, genParamSet);
265
266    OH_Huks_FreeParamSet(&genParamSet);
267    OH_Huks_FreeParamSet(&encryptParamSet);
268    OH_Huks_FreeParamSet(&decryptParamSet);
269
270    napi_value ret;
271    napi_create_int32(env, ohResult.errorCode, &ret);
272    return ret;
273}
274```
275