鸿蒙开发：Universal Keystore Kit（密钥管理服务）【密钥协商(C/C++)】

密钥协商(C/C++)

以协商密钥类型为ECDH，并密钥仅在HUKS内使用为例，完成密钥协商。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]。

在CMake脚本中链接相关动态库

   target_link_libraries(entry PUBLIC libhuks_ndk.z.so)

开发步骤

生成密钥

设备A、设备B各自生成一个非对称密钥，具体请参考[密钥生成]或[密钥导入]。

密钥生成时，可指定参数，OH_HUKS_TAG_DERIVED_AGREED_KEY_STORAGE_FLAG（可选），用于标识基于该密钥协商出的密钥是否由HUKS管理。

当TAG设置为OH_HUKS_STORAGE_ONLY_USED_IN_HUKS时，表示基于该密钥协商出的密钥，由HUKS管理，可保证协商密钥全生命周期不出安全环境。
当TAG设置为OH_HUKS_STORAGE_KEY_EXPORT_ALLOWED时，表示基于该密钥协商出的密钥，返回给调用方管理，由业务自行保证密钥安全。
若业务未设置TAG的具体值，表示基于该密钥协商出的密钥，即可由HUKS管理，也可返回给调用方管理，业务可在后续协商时再选择使用何种方式保护密钥。
开发前请熟悉鸿蒙开发指导文档：gitee.com/li-shizhen-skin/harmony-os/blob/master/README.md点击或者复制转到。

导出密钥

设备A、B导出非对称密钥对的公钥材料。

密钥协商

设备A、B分别基于本端私钥和对端设备的公钥，协商出共享密钥。

密钥协商时，可指定参数OH_HUKS_TAG_DERIVED_AGREED_KEY_STORAGE_FLAG（可选），用于标识协商得到的密钥是否由HUKS管理。

生成	协商	规格
OH_HUKS_STORAGE_ONLY_USED_IN_HUKS	OH_HUKS_STORAGE_ONLY_USED_IN_HUKS	密钥由HUKS管理
OH_HUKS_STORAGE_KEY_EXPORT_ALLOWED	OH_HUKS_STORAGE_KEY_EXPORT_ALLOWED	密钥返回给调用方管理
未指定TAG具体值	OH_HUKS_STORAGE_ONLY_USED_IN_HUKS	密钥由HUKS管理
未指定TAG具体值	OH_HUKS_STORAGE_KEY_EXPORT_ALLOWED	密钥返回给调用方管理
未指定TAG具体值	未指定TAG具体值 `HarmonyOS与OpenHarmony鸿蒙文档籽料：mau123789是v直接拿`	密钥返回给调用方管理

在这里插入图片描述

注：协商时指定的TAG值，不可与生成时指定的TAG值冲突。表格中仅列举有效的指定方式。

删除密钥

当密钥废弃不用时，设备A、B均需要删除密钥

#include "huks/native_huks_api.h"
#include "huks/native_huks_param.h"
#include <string.h>
/* 初始化参数 */
OH_Huks_Result InitParamSet(struct OH_Huks_ParamSet **paramSet,const struct OH_Huks_Param *params,uint32_t paramCount)
{OH_Huks_Result ret = OH_Huks_InitParamSet(paramSet);if (ret.errorCode != OH_HUKS_SUCCESS) {return ret;}ret = OH_Huks_AddParams(*paramSet, params, paramCount);if (ret.errorCode != OH_HUKS_SUCCESS) {OH_Huks_FreeParamSet(paramSet);return ret;}ret = OH_Huks_BuildParamSet(paramSet);if (ret.errorCode != OH_HUKS_SUCCESS) {OH_Huks_FreeParamSet(paramSet);return ret;}return ret;
}
static const uint32_t IV_SIZE = 16;
static uint8_t IV[IV_SIZE] = { 0 }; // this is a test value, for real use the iv should be different every time
static struct OH_Huks_Blob g_keyAliasFinal1001 = {(uint32_t)strlen("HksECDHAgreeKeyAliasTest001_1_final"),(uint8_t *)"HksECDHAgreeKeyAliasTest001_1_final"
};
/* 集成密钥参数集 */
static struct OH_Huks_Param g_genAgreeParams[] = {{.tag = OH_HUKS_TAG_ALGORITHM,.uint32Param = OH_HUKS_ALG_ECC}, {.tag = OH_HUKS_TAG_PURPOSE,.uint32Param = OH_HUKS_KEY_PURPOSE_AGREE}, {.tag = OH_HUKS_TAG_KEY_SIZE,.uint32Param = OH_HUKS_ECC_KEY_SIZE_256}, {.tag = OH_HUKS_TAG_DIGEST,.uint32Param = OH_HUKS_DIGEST_NONE}
};
static struct OH_Huks_Param g_agreeParamsInit01[] = {{.tag = OH_HUKS_TAG_ALGORITHM,.uint32Param = OH_HUKS_ALG_ECDH}, {.tag = OH_HUKS_TAG_PURPOSE,.uint32Param = OH_HUKS_KEY_PURPOSE_AGREE}, {.tag = OH_HUKS_TAG_KEY_SIZE,.uint32Param = OH_HUKS_ECC_KEY_SIZE_256}
};
static struct OH_Huks_Param g_agreeParamsFinish01[] = {{.tag = OH_HUKS_TAG_DERIVED_AGREED_KEY_STORAGE_FLAG,.uint32Param = OH_HUKS_STORAGE_ONLY_USED_IN_HUKS}, {.tag = OH_HUKS_TAG_ALGORITHM,.uint32Param = OH_HUKS_ALG_AES}, {.tag = OH_HUKS_TAG_KEY_SIZE,.uint32Param = OH_HUKS_AES_KEY_SIZE_256}, {.tag = OH_HUKS_TAG_PURPOSE,.uint32Param = OH_HUKS_KEY_PURPOSE_AGREE}, {.tag = OH_HUKS_TAG_KEY_ALIAS,.blob = g_keyAliasFinal1001}, {.tag = OH_HUKS_TAG_PADDING,.uint32Param = OH_HUKS_PADDING_NONE}, {.tag = OH_HUKS_TAG_BLOCK_MODE,.uint32Param = OH_HUKS_MODE_CBC}
};
static struct OH_Huks_Blob g_keyAliasFinal2001 = {(uint32_t)strlen("HksECDHAgreeKeyAliasTest001_2_final"),(uint8_t *)"HksECDHAgreeKeyAliasTest001_2_final"
};
static struct OH_Huks_Param g_agreeParamsInit02[] = {{.tag = OH_HUKS_TAG_ALGORITHM,.uint32Param = OH_HUKS_ALG_ECDH}, {.tag = OH_HUKS_TAG_PURPOSE,.uint32Param = OH_HUKS_KEY_PURPOSE_AGREE}, {.tag = OH_HUKS_TAG_KEY_SIZE,.uint32Param = OH_HUKS_ECC_KEY_SIZE_256}
};
static struct OH_Huks_Param g_agreeParamsFinish02[] = {{.tag = OH_HUKS_TAG_DERIVED_AGREED_KEY_STORAGE_FLAG,.uint32Param = OH_HUKS_STORAGE_ONLY_USED_IN_HUKS}, {.tag = OH_HUKS_TAG_ALGORITHM,.uint32Param = OH_HUKS_ALG_AES}, {.tag = OH_HUKS_TAG_KEY_SIZE,.uint32Param = OH_HUKS_AES_KEY_SIZE_256}, {.tag = OH_HUKS_TAG_PURPOSE,.uint32Param = OH_HUKS_KEY_PURPOSE_DERIVE}, {.tag = OH_HUKS_TAG_KEY_ALIAS,.blob = g_keyAliasFinal2001}, {.tag = OH_HUKS_TAG_PADDING,.uint32Param = OH_HUKS_PADDING_NONE}, {.tag = OH_HUKS_TAG_BLOCK_MODE,.uint32Param = OH_HUKS_MODE_CBC}
};
static const uint32_t ECDH_COMMON_SIZE = 1024;
static struct OH_Huks_Blob g_keyAlias01001 = {(uint32_t)strlen("HksECDHAgreeKeyAliasTest001_1"),(uint8_t *)"HksECDHAgreeKeyAliasTest001_1"
};
static struct OH_Huks_Blob g_keyAlias02001 = {(uint32_t)strlen("HksECDHAgreeKeyAliasTest001_2"),(uint8_t *)"HksECDHAgreeKeyAliasTest001_2"
};
OH_Huks_Result MallocAndCheckBlobData(struct OH_Huks_Blob *blob,const uint32_t blobSize)
{struct OH_Huks_Result ret;ret.errorCode = OH_HUKS_SUCCESS;blob->data = (uint8_t *)malloc(blobSize);if (blob->data == NULL) {ret.errorCode = OH_HUKS_ERR_CODE_INTERNAL_ERROR;}return ret;
}
/* 导出密钥 */
OH_Huks_Result HksEcdhAgreeExport(const struct OH_Huks_Blob *keyAlias1, const struct OH_Huks_Blob *keyAlias2,struct OH_Huks_Blob *publicKey1, struct OH_Huks_Blob *publicKey2, const struct OH_Huks_ParamSet *genParamSet)
{OH_Huks_Result ret = OH_Huks_ExportPublicKeyItem(keyAlias1, genParamSet, publicKey1);if (ret.errorCode != OH_HUKS_SUCCESS) {return ret;}ret = OH_Huks_ExportPublicKeyItem(keyAlias2, genParamSet, publicKey2);if (ret.errorCode != OH_HUKS_SUCCESS) {return ret;}return ret;
}
static const char *g_inData = "Hks_ECDH_Agree_Test_000000000000000000000000000000000000000000000000000000000000""00000000000000000000000000000000000000000000000000000000000000000000000000000000""0000000000000000000000000000000000000000000000000000000000000000000000000_string";
/* 协商密钥操作 */
OH_Huks_Result HksEcdhAgreeFinish(const struct OH_Huks_Blob *keyAlias, const struct OH_Huks_Blob *publicKey,const struct OH_Huks_ParamSet *initParamSet, const struct OH_Huks_ParamSet *finishParamSet, struct OH_Huks_Blob *outData)
{struct OH_Huks_Blob inData = {(uint32_t)strlen(g_inData),(uint8_t *)g_inData};uint8_t handleU[sizeof(uint64_t)] = {0};struct OH_Huks_Blob handle = { sizeof(uint64_t), handleU };OH_Huks_Result ret = OH_Huks_InitSession(keyAlias, initParamSet, &handle, nullptr);if (ret.errorCode != OH_HUKS_SUCCESS) {return ret;}uint8_t outDataU[ECDH_COMMON_SIZE] = {0};struct OH_Huks_Blob outDataUpdate = { ECDH_COMMON_SIZE, outDataU };ret = OH_Huks_UpdateSession(&handle, initParamSet, publicKey, &outDataUpdate);if (ret.errorCode != OH_HUKS_SUCCESS) {return ret;}ret = OH_Huks_FinishSession(&handle, finishParamSet, &inData, outData);if (ret.errorCode != OH_HUKS_SUCCESS) {return ret;}return ret;
}
/* 协商密钥整体流程 */
static napi_value AgreeKey(napi_env env, napi_callback_info info)
{struct OH_Huks_ParamSet *genParamSet = nullptr;struct OH_Huks_ParamSet *initParamSet01 = nullptr;struct OH_Huks_ParamSet *finishParamSet01 = nullptr;struct OH_Huks_ParamSet *initParamSet02 = nullptr;struct OH_Huks_ParamSet *finishParamSet02 = nullptr;struct OH_Huks_Blob publicKey01 = { .size = OH_HUKS_ECC_KEY_SIZE_256, .data = nullptr };struct OH_Huks_Blob publicKey02 = { .size = OH_HUKS_ECC_KEY_SIZE_256, .data = nullptr };struct OH_Huks_Blob outData01 = { .size = ECDH_COMMON_SIZE, .data = nullptr };struct OH_Huks_Blob outData02 = { .size = ECDH_COMMON_SIZE, .data = nullptr };OH_Huks_Result ohResult;do {/* 1.确定密钥别名集成密钥参数集 */ohResult = InitParamSet(&genParamSet, g_genAgreeParams, sizeof(g_genAgreeParams) / sizeof(OH_Huks_Param));if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}ohResult = InitParamSet(&initParamSet01, g_agreeParamsInit01, sizeof(g_agreeParamsInit01) / sizeof(OH_Huks_Param));if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}ohResult = InitParamSet(&finishParamSet01, g_agreeParamsFinish01,sizeof(g_agreeParamsFinish01) / sizeof(OH_Huks_Param));if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}ohResult = InitParamSet(&initParamSet02, g_agreeParamsInit02, sizeof(g_agreeParamsInit02) / sizeof(OH_Huks_Param));if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}ohResult = InitParamSet(&finishParamSet02, g_agreeParamsFinish02,sizeof(g_agreeParamsFinish02) / sizeof(OH_Huks_Param));if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}/* 2.设备A生成密钥 */ohResult = OH_Huks_GenerateKeyItem(&g_keyAlias01001, genParamSet, nullptr);if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}/* 3.设备B生成密钥 */ohResult = OH_Huks_GenerateKeyItem(&g_keyAlias02001, genParamSet, nullptr);if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}ohResult = MallocAndCheckBlobData(&publicKey01, publicKey01.size);if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}ohResult = MallocAndCheckBlobData(&publicKey02, publicKey02.size);if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}/* 4.设备A、B导出公钥 */ohResult = HksEcdhAgreeExport(&g_keyAlias01001, &g_keyAlias02001, &publicKey01, &publicKey02, genParamSet);if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}ohResult = MallocAndCheckBlobData(&outData01, outData01.size);if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}ohResult = MallocAndCheckBlobData(&outData02, outData02.size);if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}/* 5.设备A协商密钥 */ohResult = HksEcdhAgreeFinish(&g_keyAlias01001, &publicKey02, initParamSet01, finishParamSet01, &outData01);if (ohResult.errorCode != OH_HUKS_SUCCESS) {break;}/* 5.设备B协商密钥 */ohResult = HksEcdhAgreeFinish(&g_keyAlias02001, &publicKey01, initParamSet02, finishParamSet02, &outData02);} while (0);free(publicKey01.data);free(publicKey02.data);free(outData01.data);free(outData02.data);/* 6.设备A、B删除密钥 */OH_Huks_DeleteKeyItem(&g_keyAlias01001, genParamSet);OH_Huks_DeleteKeyItem(&g_keyAlias02001, genParamSet);OH_Huks_DeleteKeyItem(&g_keyAliasFinal1001, NULL);OH_Huks_DeleteKeyItem(&g_keyAliasFinal2001, NULL);OH_Huks_FreeParamSet(&genParamSet);OH_Huks_FreeParamSet(&initParamSet01);OH_Huks_FreeParamSet(&finishParamSet01);OH_Huks_FreeParamSet(&initParamSet02);OH_Huks_FreeParamSet(&finishParamSet02);napi_value ret;napi_create_int32(env, ohResult.errorCode, &ret);return ret;
}