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1# Importing a Key in Ciphertext (C/C++)
2
3
4This topic walks you through on how to import an ECDH key pair. However, the example does not cover the operations such as [key generation](huks-key-generation-overview.md) and [key agreement](huks-key-agreement-overview.md) of the service side.
5
6
7For details about the scenarios and supported algorithm specifications, see [Supported Algorithms](huks-key-import-overview.md#supported-algorithms).
8
9## Add the dynamic library in the CMake script.
10```txt
11   target_link_libraries(entry PUBLIC libhuks_ndk.z.so)
12```
13
14## How to Develop
15
161. Convert the key to be imported from device A (device from which the key is imported) to [HUKS key material format](huks-concepts.md#key material format) **To_Import_Key**. (This step applies only to asymmetric key pairs. If the key to be imported is a symmetric key, skip over this step.)
17
182. Generate an asymmetric key pair **Wrapping_Key** (public key **Wrapping_Pk** and private key **Wrapping_Sk**) with the purpose of **HUKS_KEY_PURPOSE_UNWRAP** for device B (device to which the key is imported), and export the public key **Wrapping_Pk** of **Wrapping_Key** and save it. The asymmetric key pair **Wrapping_Key** is used for key agreement in the encrypted import process.
19
203. Use the same algorithm to generate an asymmetric key pair **Caller_Key** (public key **Caller_Pk** and private key **Caller_Sk**) with the purpose of **HUKS_KEY_PURPOSE_UNWRAP** for device A, and export the public key **Caller_Pk** of **Caller_Key** and save it. The asymmetric key pair **Caller_Key** is used for key agreement in the encrypted import process.
21
224. Generate a symmetric key **Caller_Kek** for device A. This key is used to encrypt **To_Import_Key**.
23
245. Perform key agreement with the private key **Caller_Sk** in **Caller_Key** of device A and the public key **Wrapping_Pk** in **Wrapping_Key** of device B to yield a **Shared_Key**.
25
266. Use **Caller_Kek** to encrypt **To_Import_Key** of device A and generate **To_Import_Key_Enc**.
27
287. Use **Shared_Key** to encrypt **Caller_Kek** of device A and generate **Caller_Kek_Enc**.
29
308. Encapsulate the key material **Caller_Pk**, **Caller_Kek_Enc**, and **To_Import_Key_Enc** of device A, and sends it to device B. For details about the format of the key material to be imported, see [Key Material Format for Encrypted Import](huks-key-import-overview.md#key-material-format-for-encrypted-import).
31
329. Import the encrypted key material to device B.
33
3410. Delete the intermediate keys (keys used for encrypting the key to import) from devices A and B.
35
36```c++
37#include "napi/native_api.h"
38#include "huks/native_huks_api.h"
39#include "huks/native_huks_param.h"
40#include <algorithm>
41OH_Huks_Result InitParamSet(struct OH_Huks_ParamSet **paramSet, const struct OH_Huks_Param *params,
42                            uint32_t paramCount) {
43    OH_Huks_Result ret = OH_Huks_InitParamSet(paramSet);
44    if (ret.errorCode != OH_HUKS_SUCCESS) {
45        return ret;
46    }
47    ret = OH_Huks_AddParams(*paramSet, params, paramCount);
48    if (ret.errorCode != OH_HUKS_SUCCESS) {
49        OH_Huks_FreeParamSet(paramSet);
50        return ret;
51    }
52    ret = OH_Huks_BuildParamSet(paramSet);
53    if (ret.errorCode != OH_HUKS_SUCCESS) {
54        OH_Huks_FreeParamSet(paramSet);
55        return ret;
56    }
57    return ret;
58}
59struct HksImportWrappedKeyTestParams {
60    // server key, for real
61    struct OH_Huks_Blob *wrappingKeyAlias;
62    struct OH_Huks_ParamSet *genWrappingKeyParamSet;
63    uint32_t publicKeySize;
64    struct OH_Huks_Blob *callerKeyAlias;
65    struct OH_Huks_ParamSet *genCallerKeyParamSet;
66    struct OH_Huks_Blob *callerKekAlias;
67    struct OH_Huks_Blob *callerKek;
68    struct OH_Huks_ParamSet *importCallerKekParamSet;
69    struct OH_Huks_Blob *callerAgreeKeyAlias;
70    struct OH_Huks_ParamSet *agreeParamSet;
71    struct OH_Huks_ParamSet *importWrappedKeyParamSet;
72    struct OH_Huks_Blob *importedKeyAlias;
73    struct OH_Huks_Blob *importedPlainKey;
74    uint32_t keyMaterialLen;
75};
76static const uint32_t IV_SIZE = 16;
77static uint8_t IV[IV_SIZE] = "babababababab"; // Test data only. The value must be different each time.
78static const uint32_t WRAPPED_KEY_IV_SIZE = 16;
79static uint8_t WRAPPED_KEY_IV[IV_SIZE] = "bababababababab"; // Test data only. The value must be different each time.
80static const uint32_t AAD_SIZE = 16;
81static uint8_t AAD[AAD_SIZE] = "abababababababa"; // Test data only. The value must be different each time.
82static const uint32_t NONCE_SIZE = 12;
83static uint8_t NONCE[NONCE_SIZE] = "hahahahahah"; // Test data only. The value must be different each time.
84static const uint32_t AEAD_TAG_SIZE = 16;
85static const uint32_t X25519_256_SIZE = 256;
86static struct OH_Huks_Blob g_wrappingKeyAliasAes256 = {.size = (uint32_t)strlen("test_wrappingKey_x25519_aes256"),
87                                                       .data = (uint8_t *)"test_wrappingKey_x25519_aes256"};
88static struct OH_Huks_Blob g_callerKeyAliasAes256 = {.size = (uint32_t)strlen("test_caller_key_x25519_aes256"),
89                                                     .data = (uint8_t *)"test_caller_key_x25519_aes256"};
90static struct OH_Huks_Blob g_callerKekAliasAes256 = {.size = (uint32_t)strlen("test_caller_kek_x25519_aes256"),
91                                                     .data = (uint8_t *)"test_caller_kek_x25519_aes256"};
92static struct OH_Huks_Blob g_callerAes256Kek = {.size = (uint32_t)strlen("This is kek to encrypt plain key"),
93                                                .data = (uint8_t *)"This is kek to encrypt plain key"};
94static struct OH_Huks_Blob g_callerAgreeKeyAliasAes256 = {.size =
95                                                              (uint32_t)strlen("test_caller_agree_key_x25519_aes256"),
96                                                          .data = (uint8_t *)"test_caller_agree_key_x25519_aes256"};
97static struct OH_Huks_Blob g_importedKeyAliasAes256 = {.size = (uint32_t)strlen("test_import_key_x25519_aes256"),
98                                                       .data = (uint8_t *)"test_import_key_x25519_aes256"};
99static struct OH_Huks_Blob g_importedAes256PlainKey = {.size = (uint32_t)strlen("This is plain key to be imported"),
100                                                       .data = (uint8_t *)"This is plain key to be imported"};
101static struct OH_Huks_Param g_importWrappedAes256Params[] = {
102    {.tag = OH_HUKS_TAG_ALGORITHM, .uint32Param = OH_HUKS_ALG_AES},
103    {.tag = OH_HUKS_TAG_PURPOSE, .uint32Param = OH_HUKS_KEY_PURPOSE_ENCRYPT | OH_HUKS_KEY_PURPOSE_DECRYPT},
104    {.tag = OH_HUKS_TAG_KEY_SIZE, .uint32Param = OH_HUKS_AES_KEY_SIZE_256},
105    {.tag = OH_HUKS_TAG_PADDING, .uint32Param = OH_HUKS_PADDING_NONE},
106    {.tag = OH_HUKS_TAG_BLOCK_MODE, .uint32Param = OH_HUKS_MODE_GCM},
107    {.tag = OH_HUKS_TAG_DIGEST, .uint32Param = OH_HUKS_DIGEST_NONE},
108    {.tag = OH_HUKS_TAG_UNWRAP_ALGORITHM_SUITE, .uint32Param = OH_HUKS_UNWRAP_SUITE_X25519_AES_256_GCM_NOPADDING},
109    {.tag = OH_HUKS_TAG_ASSOCIATED_DATA,
110     .blob = {.size = AAD_SIZE, .data = (uint8_t *)AAD}}, // Test data only. The value varies with the caller information.
111    {.tag = OH_HUKS_TAG_NONCE,
112     .blob = {.size = NONCE_SIZE, .data = (uint8_t *)NONCE}}}; // Test data only. The value must be different each time.
113static const uint32_t g_x25519PubKeySize = 32;
114static struct OH_Huks_Param g_genWrappingKeyParams[] = {
115    {.tag = OH_HUKS_TAG_ALGORITHM, .uint32Param = OH_HUKS_ALG_X25519},
116    {.tag = OH_HUKS_TAG_PURPOSE, .uint32Param = OH_HUKS_KEY_PURPOSE_UNWRAP},
117    {.tag = OH_HUKS_TAG_KEY_SIZE, .uint32Param = OH_HUKS_CURVE25519_KEY_SIZE_256}};
118static struct OH_Huks_Param g_genCallerX25519Params[] = {
119    {.tag = OH_HUKS_TAG_ALGORITHM, .uint32Param = OH_HUKS_ALG_X25519},
120    {.tag = OH_HUKS_TAG_PURPOSE, .uint32Param = OH_HUKS_KEY_PURPOSE_AGREE},
121    {.tag = OH_HUKS_TAG_KEY_SIZE, .uint32Param = OH_HUKS_CURVE25519_KEY_SIZE_256}};
122static struct OH_Huks_Param g_importParamsCallerKek[] = {
123    {.tag = OH_HUKS_TAG_ALGORITHM, .uint32Param = OH_HUKS_ALG_AES},
124    {.tag = OH_HUKS_TAG_PURPOSE, .uint32Param = OH_HUKS_KEY_PURPOSE_ENCRYPT},
125    {.tag = OH_HUKS_TAG_KEY_SIZE, .uint32Param = OH_HUKS_AES_KEY_SIZE_256},
126    {.tag = OH_HUKS_TAG_PADDING, .uint32Param = OH_HUKS_PADDING_NONE},
127    {.tag = OH_HUKS_TAG_BLOCK_MODE, .uint32Param = OH_HUKS_MODE_GCM},
128    {.tag = OH_HUKS_TAG_DIGEST, .uint32Param = OH_HUKS_DIGEST_NONE},
129    {.tag = OH_HUKS_TAG_IV,
130     .blob = {.size = WRAPPED_KEY_IV_SIZE,
131              .data = (uint8_t *)WRAPPED_KEY_IV}}}; // Test data only. The value must be different each time.
132static struct OH_Huks_Param g_callerAgreeParams[] = {
133    {.tag = OH_HUKS_TAG_ALGORITHM, .uint32Param = OH_HUKS_ALG_X25519},
134    {.tag = OH_HUKS_TAG_PURPOSE, .uint32Param = OH_HUKS_KEY_PURPOSE_AGREE},
135    {.tag = OH_HUKS_TAG_KEY_SIZE, .uint32Param = OH_HUKS_CURVE25519_KEY_SIZE_256}};
136static struct OH_Huks_Param g_aesKekEncryptParams[] = {
137    {.tag = OH_HUKS_TAG_ALGORITHM, .uint32Param = OH_HUKS_ALG_AES},
138    {.tag = OH_HUKS_TAG_PURPOSE, .uint32Param = OH_HUKS_KEY_PURPOSE_ENCRYPT},
139    {.tag = OH_HUKS_TAG_KEY_SIZE, .uint32Param = OH_HUKS_AES_KEY_SIZE_256},
140    {.tag = OH_HUKS_TAG_PADDING, .uint32Param = OH_HUKS_PADDING_NONE},
141    {.tag = OH_HUKS_TAG_BLOCK_MODE, .uint32Param = OH_HUKS_MODE_GCM},
142    {.tag = OH_HUKS_TAG_DIGEST, .uint32Param = OH_HUKS_DIGEST_NONE},
143    {.tag = OH_HUKS_TAG_ASSOCIATED_DATA,
144     .blob = {.size = AAD_SIZE, .data = (uint8_t *)AAD}}, // Test data only. The value varies with the caller information.
145    {.tag = OH_HUKS_TAG_NONCE,
146     .blob = {.size = NONCE_SIZE, .data = (uint8_t *)NONCE}}}; // Test data only. The value must be different each time.
147static struct OH_Huks_Param g_importAgreeKeyParams[] = {
148    {.tag = OH_HUKS_TAG_ALGORITHM, .uint32Param = OH_HUKS_ALG_AES},
149    {.tag = OH_HUKS_TAG_PURPOSE, .uint32Param = OH_HUKS_KEY_PURPOSE_ENCRYPT},
150    {.tag = OH_HUKS_TAG_KEY_SIZE, .uint32Param = OH_HUKS_AES_KEY_SIZE_256},
151    {.tag = OH_HUKS_TAG_PADDING, .uint32Param = OH_HUKS_PADDING_NONE},
152    {.tag = OH_HUKS_TAG_BLOCK_MODE, .uint32Param = OH_HUKS_MODE_GCM},
153    {.tag = OH_HUKS_TAG_DIGEST, .uint32Param = OH_HUKS_DIGEST_NONE},
154    {.tag = OH_HUKS_TAG_IV,
155     .blob = {.size = IV_SIZE, .data = (uint8_t *)IV}}}; // Test data only. The value must be different each time.
156OH_Huks_Result HuksAgreeKey(const struct OH_Huks_ParamSet *paramSet, const struct OH_Huks_Blob *keyAlias,
157                            const struct OH_Huks_Blob *peerPublicKey, struct OH_Huks_Blob *agreedKey) {
158    uint8_t temp[10] = {0};
159    struct OH_Huks_Blob inData = {sizeof(temp), temp};
160    uint8_t handleU[sizeof(uint64_t)] = {0};
161    struct OH_Huks_Blob handle = {sizeof(uint64_t), handleU};
162    OH_Huks_Result ret = OH_Huks_InitSession(keyAlias, paramSet, &handle, nullptr);
163    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
164        return ret;
165    }
166    uint8_t outDataU[1024] = {0};
167    struct OH_Huks_Blob outDataUpdate = {1024, outDataU};
168    ret = OH_Huks_UpdateSession(&handle, paramSet, peerPublicKey, &outDataUpdate);
169    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
170        return ret;
171    }
172    ret = OH_Huks_FinishSession(&handle, paramSet, &inData, agreedKey);
173    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
174        return ret;
175    }
176    return ret;
177}
178OH_Huks_Result MallocAndCheckBlobData(struct OH_Huks_Blob *blob, const uint32_t blobSize) {
179    struct OH_Huks_Result ret;
180    ret.errorCode = OH_HUKS_SUCCESS;
181    blob->data = (uint8_t *)malloc(blobSize);
182    if (blob->data == NULL) {
183        ret.errorCode = OH_HUKS_ERR_CODE_INTERNAL_ERROR;
184    }
185    return ret;
186}
187static const uint32_t TIMES = 4;
188static const uint32_t MAX_UPDATE_SIZE = 64;
189static const uint32_t MAX_OUTDATA_SIZE = MAX_UPDATE_SIZE * TIMES;
190#define HUKS_FREE_BLOB(blob)                                                                                           \
191    do {                                                                                                               \
192        if ((blob).data != nullptr) {                                                                                  \
193            free((blob).data);                                                                                         \
194            (blob).data = nullptr;                                                                                     \
195        }                                                                                                              \
196        (blob).size = 0;                                                                                               \
197    } while (0)
198#define OH_HUKS_KEY_BYTES(keySize) (((keySize) + 7) / 8)
199static OH_Huks_Result HksEncryptLoopUpdate(const struct OH_Huks_Blob *handle, const struct OH_Huks_ParamSet *paramSet,
200                                           const struct OH_Huks_Blob *inData, struct OH_Huks_Blob *outData) {
201    struct OH_Huks_Result ret;
202    ret.errorCode = OH_HUKS_SUCCESS;
203    struct OH_Huks_Blob inDataSeg = *inData;
204    uint8_t *lastPtr = inData->data + inData->size - 1;
205    struct OH_Huks_Blob outDataSeg = {MAX_OUTDATA_SIZE, NULL};
206    uint8_t *cur = outData->data;
207    outData->size = 0;
208    inDataSeg.size = MAX_UPDATE_SIZE;
209    bool isFinished = false;
210    while (inDataSeg.data <= lastPtr) {
211        if (inDataSeg.data + MAX_UPDATE_SIZE <= lastPtr) {
212            outDataSeg.size = MAX_OUTDATA_SIZE;
213        } else {
214            isFinished = true;
215            inDataSeg.size = lastPtr - inDataSeg.data + 1;
216            break;
217        }
218        if (MallocAndCheckBlobData(&outDataSeg, outDataSeg.size).errorCode != (int32_t)OH_HUKS_SUCCESS) {
219            ret.errorCode = OH_HUKS_ERR_CODE_INTERNAL_ERROR;
220            return ret;
221        }
222        ret = OH_Huks_UpdateSession(handle, paramSet, &inDataSeg, &outDataSeg);
223        if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
224            free(outDataSeg.data);
225            return ret;
226        }
227        std::copy(outDataSeg.data, outDataSeg.data + outDataSeg.size, cur);
228        cur += outDataSeg.size;
229        outData->size += outDataSeg.size;
230        free(outDataSeg.data);
231        if ((isFinished == false) && (inDataSeg.data + MAX_UPDATE_SIZE > lastPtr)) {
232            ret.errorCode = OH_HUKS_ERR_CODE_INTERNAL_ERROR;
233            return ret;
234        }
235        inDataSeg.data += MAX_UPDATE_SIZE;
236    }
237    struct OH_Huks_Blob outDataFinish = {inDataSeg.size * TIMES, NULL};
238    if (MallocAndCheckBlobData(&outDataFinish, outDataFinish.size).errorCode != (int32_t)OH_HUKS_SUCCESS) {
239        ret.errorCode = OH_HUKS_ERR_CODE_INTERNAL_ERROR;
240        return ret;
241    }
242    ret = OH_Huks_FinishSession(handle, paramSet, &inDataSeg, &outDataFinish);
243    if (ret.errorCode != OH_HUKS_SUCCESS) {
244        free(outDataFinish.data);
245        return ret;
246    }
247    std::copy(outDataFinish.data, outDataFinish.data + outDataFinish.size, cur);
248    outData->size += outDataFinish.size;
249    free(outDataFinish.data);
250    return ret;
251}
252OH_Huks_Result HuksEncrypt(const struct OH_Huks_Blob *key, const struct OH_Huks_ParamSet *paramSet,
253                           const struct OH_Huks_Blob *plainText, struct OH_Huks_Blob *cipherText) {
254    uint8_t handle[sizeof(uint64_t)] = {0};
255    struct OH_Huks_Blob handleBlob = {sizeof(uint64_t), handle};
256    OH_Huks_Result ret = OH_Huks_InitSession(key, paramSet, &handleBlob, nullptr);
257    if (ret.errorCode != OH_HUKS_SUCCESS) {
258        return ret;
259    }
260    ret = HksEncryptLoopUpdate(&handleBlob, paramSet, plainText, cipherText);
261    return ret;
262}
263static OH_Huks_Result BuildWrappedKeyData(struct OH_Huks_Blob **blobArray, uint32_t size,
264                                          struct OH_Huks_Blob *outData) {
265    uint32_t totalLength = size * sizeof(uint32_t);
266    struct OH_Huks_Result ret;
267    ret.errorCode = OH_HUKS_SUCCESS;
268    /* Data size. */
269    for (uint32_t i = 0; i < size; ++i) {
270        totalLength += blobArray[i]->size;
271    }
272    struct OH_Huks_Blob outBlob = {0, nullptr};
273    outBlob.size = totalLength;
274    ret = MallocAndCheckBlobData(&outBlob, outBlob.size);
275    if (ret.errorCode != OH_HUKS_SUCCESS) {
276        return ret;
277    }
278    uint32_t offset = 0;
279    /* Copy data. */
280    for (uint32_t i = 0; i < size; ++i) {
281        if (totalLength - offset >= sizeof(blobArray[i]->size)) {
282            std::copy(reinterpret_cast<uint8_t *>(&blobArray[i]->size),
283                      reinterpret_cast<uint8_t *>(&blobArray[i]->size) + sizeof(blobArray[i]->size),
284                      outBlob.data + offset);
285        } else {
286            ret.errorCode = OH_HUKS_ERR_CODE_INTERNAL_ERROR;
287            return ret;
288        }
289        offset += sizeof(blobArray[i]->size);
290        if (totalLength - offset >= blobArray[i]->size) {
291            std::copy(blobArray[i]->data, blobArray[i]->data + blobArray[i]->size, outBlob.data + offset);
292        } else {
293            ret.errorCode = OH_HUKS_ERR_CODE_INTERNAL_ERROR;
294            return ret;
295        }
296        offset += blobArray[i]->size;
297    }
298    outData->size = outBlob.size;
299    outData->data = outBlob.data;
300    return ret;
301}
302static OH_Huks_Result CheckParamsValid(const struct HksImportWrappedKeyTestParams *params) {
303    struct OH_Huks_Result ret;
304    ret.errorCode = OH_HUKS_SUCCESS;
305    if (params == nullptr) {
306        ret.errorCode = OH_HUKS_ERR_CODE_ILLEGAL_ARGUMENT;
307        return ret;
308    }
309    if (params->wrappingKeyAlias == nullptr || params->genWrappingKeyParamSet == nullptr ||
310        params->callerKeyAlias == nullptr || params->genCallerKeyParamSet == nullptr ||
311        params->callerKekAlias == nullptr || params->callerKek == nullptr ||
312        params->importCallerKekParamSet == nullptr || params->callerAgreeKeyAlias == nullptr ||
313        params->agreeParamSet == nullptr || params->importWrappedKeyParamSet == nullptr ||
314        params->importedKeyAlias == nullptr || params->importedPlainKey == nullptr) {
315        ret.errorCode = OH_HUKS_ERR_CODE_ILLEGAL_ARGUMENT;
316        return ret;
317    }
318    return ret;
319}
320static OH_Huks_Result GenerateAndExportHuksPublicKey(const struct HksImportWrappedKeyTestParams *params,
321                                                     struct OH_Huks_Blob *huksPublicKey) {
322    OH_Huks_Result ret = OH_Huks_GenerateKeyItem(params->wrappingKeyAlias, params->genWrappingKeyParamSet, nullptr);
323    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
324        return ret;
325    }
326    huksPublicKey->size = params->publicKeySize;
327    ret = MallocAndCheckBlobData(huksPublicKey, huksPublicKey->size);
328    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
329        return ret;
330    }
331    ret = OH_Huks_ExportPublicKeyItem(params->wrappingKeyAlias, nullptr, huksPublicKey);
332    return ret;
333}
334static OH_Huks_Result GenerateAndExportCallerPublicKey(const struct HksImportWrappedKeyTestParams *params,
335                                                       struct OH_Huks_Blob *callerSelfPublicKey) {
336    OH_Huks_Result ret = OH_Huks_GenerateKeyItem(params->callerKeyAlias, params->genCallerKeyParamSet, nullptr);
337    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
338        return ret;
339    }
340    callerSelfPublicKey->size = params->publicKeySize;
341    ret = MallocAndCheckBlobData(callerSelfPublicKey, callerSelfPublicKey->size);
342    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
343        return ret;
344    }
345    ret = OH_Huks_ExportPublicKeyItem(params->callerKeyAlias, params->genWrappingKeyParamSet, callerSelfPublicKey);
346    return ret;
347}
348static OH_Huks_Result ImportKekAndAgreeSharedSecret(const struct HksImportWrappedKeyTestParams *params,
349                                                    const struct OH_Huks_Blob *huksPublicKey,
350                                                    struct OH_Huks_Blob *outSharedKey) {
351    OH_Huks_Result ret =
352        OH_Huks_ImportKeyItem(params->callerKekAlias, params->importCallerKekParamSet, params->callerKek);
353    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
354        return ret;
355    }
356    ret = MallocAndCheckBlobData(outSharedKey, outSharedKey->size);
357    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
358        return ret;
359    }
360    ret = HuksAgreeKey(params->agreeParamSet, params->callerKeyAlias, huksPublicKey, outSharedKey);
361    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
362        return ret;
363    }
364    struct OH_Huks_ParamSet *importAgreeKeyParams = nullptr;
365    ret = InitParamSet(&importAgreeKeyParams, g_importAgreeKeyParams,
366                       sizeof(g_importAgreeKeyParams) / sizeof(OH_Huks_Param));
367    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
368        return ret;
369    }
370    ret = OH_Huks_ImportKeyItem(params->callerAgreeKeyAlias, importAgreeKeyParams, outSharedKey);
371    OH_Huks_FreeParamSet(&importAgreeKeyParams);
372    return ret;
373}
374static OH_Huks_Result EncryptImportedPlainKeyAndKek(const struct HksImportWrappedKeyTestParams *params,
375                                                    struct OH_Huks_Blob *plainCipherText,
376                                                    struct OH_Huks_Blob *kekCipherText) {
377    struct OH_Huks_ParamSet *encryptParamSet = nullptr;
378    OH_Huks_Result ret =
379        InitParamSet(&encryptParamSet, g_aesKekEncryptParams, sizeof(g_aesKekEncryptParams) / sizeof(OH_Huks_Param));
380    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
381        return ret;
382    }
383    ret = HuksEncrypt(params->callerKekAlias, encryptParamSet, params->importedPlainKey, plainCipherText);
384    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
385        return ret;
386    }
387    ret = HuksEncrypt(params->callerAgreeKeyAlias, encryptParamSet, params->callerKek, kekCipherText);
388    OH_Huks_FreeParamSet(&encryptParamSet);
389    return ret;
390}
391static OH_Huks_Result ImportWrappedKey(const struct HksImportWrappedKeyTestParams *params,
392                                       struct OH_Huks_Blob *plainCipher, struct OH_Huks_Blob *kekCipherText,
393                                       struct OH_Huks_Blob *peerPublicKey, struct OH_Huks_Blob *wrappedKeyData) {
394    struct OH_Huks_Blob commonAad = {.size = AAD_SIZE, .data = reinterpret_cast<uint8_t *>(AAD)};
395    struct OH_Huks_Blob commonNonce = {.size = NONCE_SIZE, .data = reinterpret_cast<uint8_t *>(NONCE)};
396    struct OH_Huks_Blob keyMaterialLen = {.size = sizeof(uint32_t), .data = (uint8_t *)&params->keyMaterialLen};
397    /* Copy the AEAD tag from the ciphertext and reduce its size. */
398    const uint32_t tagSize = AEAD_TAG_SIZE;
399    uint8_t kekTagBuf[tagSize] = {0};
400    struct OH_Huks_Blob kekTag = {.size = tagSize, .data = kekTagBuf};
401    std::copy(plainCipher->data + (plainCipher->size - tagSize),
402              plainCipher->data + (plainCipher->size - tagSize) + tagSize, kekTag.data);
403    plainCipher->size -= tagSize;
404    /* Copy the AEAD tag from kekCipherText and reduce the tag size. */
405    uint8_t agreeKeyTagBuf[tagSize] = {0};
406    struct OH_Huks_Blob agreeKeyTag = {.size = tagSize, .data = agreeKeyTagBuf};
407    std::copy(kekCipherText->data + (kekCipherText->size - tagSize),
408              kekCipherText->data + (kekCipherText->size - tagSize) + tagSize, agreeKeyTagBuf);
409    kekCipherText->size -= tagSize;
410    struct OH_Huks_Blob *blobArray[] = {peerPublicKey, &commonAad,   &commonNonce, &agreeKeyTag,    kekCipherText,
411                                        &commonAad,    &commonNonce, &kekTag,      &keyMaterialLen, plainCipher};
412    OH_Huks_Result ret = BuildWrappedKeyData(blobArray, OH_HUKS_IMPORT_WRAPPED_KEY_TOTAL_BLOBS, wrappedKeyData);
413    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
414        return ret;
415    }
416    struct OH_Huks_Param *purpose = nullptr;
417    ret = OH_Huks_GetParam(params->importWrappedKeyParamSet, OH_HUKS_TAG_PURPOSE, &purpose);
418    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
419        return ret;
420    }
421    ret = OH_Huks_ImportWrappedKeyItem(params->importedKeyAlias, params->wrappingKeyAlias,
422                                       params->importWrappedKeyParamSet, wrappedKeyData);
423    return ret;
424}
425OH_Huks_Result HksImportWrappedKeyTestCommonCase(const struct HksImportWrappedKeyTestParams *params) {
426    OH_Huks_Result ret = CheckParamsValid(params);
427    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
428        return ret;
429    }
430    struct OH_Huks_Blob huksPublicKey = {0, nullptr};
431    struct OH_Huks_Blob callerSelfPublicKey = {0, nullptr};
432    struct OH_Huks_Blob outSharedKey = {.size = OH_HUKS_KEY_BYTES(OH_HUKS_AES_KEY_SIZE_256), .data = nullptr};
433    struct OH_Huks_Blob wrappedKeyData = {0, nullptr};
434    uint8_t plainKeyCipherBuffer[OH_HUKS_MAX_KEY_SIZE] = {0};
435    struct OH_Huks_Blob plainCipherText = {OH_HUKS_MAX_KEY_SIZE, plainKeyCipherBuffer};
436    uint8_t kekCipherTextBuffer[OH_HUKS_MAX_KEY_SIZE] = {0};
437    struct OH_Huks_Blob kekCipherText = {OH_HUKS_MAX_KEY_SIZE, kekCipherTextBuffer};
438    /* Simulate the encrypted key import scenario. Import a key from device A (remote device) to device B (local device). */
439    do {
440        /**
441         * 1. If the key to be imported from device A is an asymmetric key pair, convert it into the HUKS key material format **To_Import_Key**. Skip over this step if the key is a symmetric key.
442         * This example uses a 256-bit AES key (symmetric key) as an example.
443         */
444        /* 2. Generate an asymmetric key pair Wrapping_Key (public key Wrapping_Pk and private key Wrapping_Sk) with the purpose of HUKS_KEY_PURPOSE_UNWRAP for device B, export the public key Wrapping_Pk of Wrapping_Key, and save it to huksPubKey.
445         */
446        ret = GenerateAndExportHuksPublicKey(params, &huksPublicKey);
447        if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
448            break;
449        }
450        /* 3. Use the same algorithm to generate an asymmetric key pair Caller_Key (public key Caller_Pk and private key Caller_Sk) with the purpose of HUKS_KEY_PURPOSE_UNWRAP for device A, export the public key Caller_Pk of Caller_Key, save it to callerSelfPublicKey.
451         */
452        ret = GenerateAndExportCallerPublicKey(params, &callerSelfPublicKey);
453        if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
454            break;
455        }
456        /**
457         4. Generate a symmetric key Caller_Kek for device A. This key is used to encrypt To_Import_Key.
458         * 5. Perform key agreement with the private key **Caller_Sk** in **Caller_Key** of device A and the public key **Wrapping_Pk** in **Wrapping_Key** of device B to yield a **Shared_Key**.
459         */
460        ret = ImportKekAndAgreeSharedSecret(params, &huksPublicKey, &outSharedKey);
461        if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
462            break;
463        }
464        /**
465         * 6. Use Caller_Kek to encrypt To_Import_Key of device A and generate To_Import_Key_Enc.
466         * 7. Use Shared_Key to encrypt Caller_Kek of device A and generate Caller_Kek_Enc.
467         */
468        ret = EncryptImportedPlainKeyAndKek(params, &plainCipherText, &kekCipherText);
469        if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
470            break;
471        }
472        /* 8. Encapsulate the key material Caller_Pk, To_Import_Key_Enc, and Caller_Kek_Enc of device A, and sends it to device B.
473         * In this example, Caller_Pk is placed in callerSelfPublicKey, To_Import_Key_Enc in PlainKeyEncData, and Caller_Kek_Enc in KekEncData.
474         * 9. Import the encapsulated key material to device B.
475         */
476        ret = ImportWrappedKey(params, &plainCipherText, &kekCipherText, &callerSelfPublicKey, &wrappedKeyData);
477    } while (0);
478    /* 10. Delete the intermediate keys (keys used for encrypting the key to import) from devices A and B. */
479    HUKS_FREE_BLOB(huksPublicKey);
480    HUKS_FREE_BLOB(callerSelfPublicKey);
481    HUKS_FREE_BLOB(outSharedKey);
482    HUKS_FREE_BLOB(wrappedKeyData);
483    return ret;
484}
485void HksClearKeysForWrappedKeyTest(const struct HksImportWrappedKeyTestParams *params) {
486    OH_Huks_Result ret = CheckParamsValid(params);
487    if (ret.errorCode != (int32_t)OH_HUKS_SUCCESS) {
488        return;
489    }
490    (void)OH_Huks_DeleteKeyItem(params->wrappingKeyAlias, nullptr);
491    (void)OH_Huks_DeleteKeyItem(params->callerKeyAlias, nullptr);
492    (void)OH_Huks_DeleteKeyItem(params->callerKekAlias, nullptr);
493    (void)OH_Huks_DeleteKeyItem(params->callerAgreeKeyAlias, nullptr);
494    (void)OH_Huks_DeleteKeyItem(params->importedKeyAlias, nullptr);
495}
496static OH_Huks_Result InitCommonTestParamsAndDoImport(struct HksImportWrappedKeyTestParams *importWrappedKeyTestParams,
497                                                      const struct OH_Huks_Param *importedKeyParamSetArray,
498                                                      uint32_t arraySize) {
499    struct OH_Huks_ParamSet *genX25519KeyParamSet = nullptr;
500    struct OH_Huks_ParamSet *genCallerKeyParamSet = nullptr;
501    struct OH_Huks_ParamSet *callerImportParamsKek = nullptr;
502    struct OH_Huks_ParamSet *agreeParamSet = nullptr;
503    struct OH_Huks_ParamSet *importPlainKeyParams = nullptr;
504    OH_Huks_Result ret;
505    do {
506        ret = InitParamSet(&genX25519KeyParamSet, g_genWrappingKeyParams,
507                           sizeof(g_genWrappingKeyParams) / sizeof(OH_Huks_Param));
508        if (ret.errorCode != OH_HUKS_SUCCESS) {
509            break;
510        }
511        importWrappedKeyTestParams->genWrappingKeyParamSet = genX25519KeyParamSet;
512        importWrappedKeyTestParams->publicKeySize = g_x25519PubKeySize;
513        ret = InitParamSet(&genCallerKeyParamSet, g_genCallerX25519Params,
514                           sizeof(g_genCallerX25519Params) / sizeof(OH_Huks_Param));
515        if (ret.errorCode != OH_HUKS_SUCCESS) {
516            break;
517        }
518        importWrappedKeyTestParams->genCallerKeyParamSet = genCallerKeyParamSet;
519        ret = InitParamSet(&callerImportParamsKek, g_importParamsCallerKek,
520                           sizeof(g_importParamsCallerKek) / sizeof(OH_Huks_Param));
521        if (ret.errorCode != OH_HUKS_SUCCESS) {
522            break;
523        }
524        importWrappedKeyTestParams->importCallerKekParamSet = callerImportParamsKek;
525        ret = InitParamSet(&agreeParamSet, g_callerAgreeParams, sizeof(g_callerAgreeParams) / sizeof(OH_Huks_Param));
526        if (ret.errorCode != OH_HUKS_SUCCESS) {
527            break;
528        }
529        importWrappedKeyTestParams->agreeParamSet = agreeParamSet;
530        ret = InitParamSet(&importPlainKeyParams, importedKeyParamSetArray, arraySize);
531        if (ret.errorCode != OH_HUKS_SUCCESS) {
532            break;
533        }
534        importWrappedKeyTestParams->importWrappedKeyParamSet = importPlainKeyParams;
535        ret = HksImportWrappedKeyTestCommonCase(importWrappedKeyTestParams);
536    } while (0);
537    OH_Huks_FreeParamSet(&genX25519KeyParamSet);
538    OH_Huks_FreeParamSet(&genCallerKeyParamSet);
539    OH_Huks_FreeParamSet(&callerImportParamsKek);
540    OH_Huks_FreeParamSet(&agreeParamSet);
541    OH_Huks_FreeParamSet(&importPlainKeyParams);
542    return ret;
543}
544static napi_value ImportWrappedKey(napi_env env, napi_callback_info info) {
545    struct HksImportWrappedKeyTestParams importWrappedKeyTestParams001 = {0};
546    importWrappedKeyTestParams001.wrappingKeyAlias = &g_wrappingKeyAliasAes256;
547    importWrappedKeyTestParams001.keyMaterialLen = g_importedAes256PlainKey.size;
548    importWrappedKeyTestParams001.callerKeyAlias = &g_callerKeyAliasAes256;
549    importWrappedKeyTestParams001.callerKekAlias = &g_callerKekAliasAes256;
550    importWrappedKeyTestParams001.callerKek = &g_callerAes256Kek;
551    importWrappedKeyTestParams001.callerAgreeKeyAlias = &g_callerAgreeKeyAliasAes256;
552    importWrappedKeyTestParams001.importedKeyAlias = &g_importedKeyAliasAes256;
553    importWrappedKeyTestParams001.importedPlainKey = &g_importedAes256PlainKey;
554    OH_Huks_Result ohResult =
555        InitCommonTestParamsAndDoImport(&importWrappedKeyTestParams001, g_importWrappedAes256Params,
556                                        sizeof(g_importWrappedAes256Params) / sizeof(struct OH_Huks_Param));
557    HksClearKeysForWrappedKeyTest(&importWrappedKeyTestParams001);
558    napi_value ret;
559    napi_create_int32(env, ohResult.errorCode, &ret);
560    return ret;
561}
562```
563
564
565## Verification
566
567Use [OH_Huks_IsKeyItemExist](../../reference/apis-universal-keystore-kit/_huks_key_api.md#oh_huks_iskeyitemexist) to check whether the key exists. If the key exists, the key is successfully imported.
568
569```c++
570#include "huks/native_huks_api.h"
571#include "huks/native_huks_param.h"
572#include <string.h>
573static napi_value IsKeyExist(napi_env env, napi_callback_info info)
574{
575    /* 1. Set the key alias. */
576    struct OH_Huks_Blob keyAlias = {
577        (uint32_t)strlen("test_key"),
578        (uint8_t *)"test_key"
579    };
580
581    /* 2. Call OH_Huks_IsKeyItemExist to check whether the key exists. */
582    struct OH_Huks_Result ohResult = OH_Huks_IsKeyItemExist(&keyAlias, NULL);
583    if (ohResult.errorCode != OH_HUKS_SUCCESS) {
584        // Operation failed.
585    } else {
586        // Operation successful.
587    }
588}
589```
590