HMAC(C/C++)

HMAC是密鑰相關的哈希運算消息認證碼（Hash-based Message Authentication Code），是一種基于Hash函數和密鑰進行消息認證的方法。

在CMake腳本中鏈接相關動態庫

target_link_libraries(entry PUBLIC libhuks_ndk.z.so)

開發步驟

生成密鑰

1. 指定密鑰別名。
2. 初始化密鑰屬性集。
3. 調用OH_Huks_GenerateKeyItem生成密鑰，HMAC支持的規格請參考[密鑰生成]。
4. 開發前請熟悉鴻蒙開發指導文檔 ：[gitee.com/li-shizhen-skin/harmony-os/blob/master/README.md]

除此之外，開發者也可以參考[密鑰導入]的規格介紹，導入已有的密鑰。

執行HMAC

1. 獲取密鑰別名。
2. 獲取待運算的數據。
3. 調用[OH_Huks_InitParamSet]指定算法參數配置。
4. 調用[OH_Huks_InitSession]初始化密鑰會話，并獲取會話的句柄handle。
5. 調用[OH_Huks_FinishSession]結束密鑰會話，獲取哈希后的數據。

#include "huks/native_huks_api.h"
#include "huks/native_huks_param.h"
#include < string.h >
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 struct OH_Huks_Param g_genHmacParams[] = {
    {
        .tag = OH_HUKS_TAG_ALGORITHM,
        .uint32Param = OH_HUKS_ALG_HMAC
    }, {
        .tag = OH_HUKS_TAG_PURPOSE,
        .uint32Param = OH_HUKS_KEY_PURPOSE_MAC
    }, {
        .tag = OH_HUKS_TAG_KEY_SIZE,
        .uint32Param = OH_HUKS_AES_KEY_SIZE_256
    }, {
        .tag = OH_HUKS_TAG_DIGEST,
        .uint32Param = OH_HUKS_DIGEST_SHA384
    }
};

static const uint32_t HMAC_COMMON_SIZE = 1024;
OH_Huks_Result HksHmacTest(
        const struct OH_Huks_Blob *keyAlias,
        const struct OH_Huks_ParamSet *hmacParamSet, const struct OH_Huks_Blob *inData, struct OH_Huks_Blob *hashText)
{
    uint8_t handleE[sizeof(uint64_t)] = {0};
    struct OH_Huks_Blob handle = {sizeof(uint64_t), handleE};
    OH_Huks_Result ret = OH_Huks_InitSession(keyAlias, hmacParamSet, &handle, nullptr);
    if (ret.errorCode != OH_HUKS_SUCCESS) {
        return ret;
    }
    ret = OH_Huks_FinishSession(&handle, hmacParamSet, inData, hashText);
    return ret;
}

static napi_value HmacKey(napi_env env, napi_callback_info info)
{
    char tmpKeyAlias[] = "test_hmac";
    struct OH_Huks_Blob keyAlias = { (uint32_t)strlen(tmpKeyAlias), (uint8_t *)tmpKeyAlias };
    struct OH_Huks_ParamSet *hmacParamSet = nullptr;
    OH_Huks_Result ohResult;
    do {
        /* 1. Generate Key */
        /*
        * 模擬生成密鑰場景
        * 1.1. 確定密鑰別名
        */
        /*
        * 1.2. 獲取生成密鑰算法參數配置
        */
        ohResult = InitParamSet(&hmacParamSet, g_genHmacParams, sizeof(g_genHmacParams) / sizeof(OH_Huks_Param));
        if (ohResult.errorCode != OH_HUKS_SUCCESS) {
            break;
        }
        /*
        * 1.3. 調用generateKeyItem
        */
        ohResult = OH_Huks_GenerateKeyItem(&keyAlias, hmacParamSet, nullptr);
        if (ohResult.errorCode != OH_HUKS_SUCCESS) {
            break;
        }
        /* 2. Hmac */
        /*
        * 模擬哈希場景
        * 2.1. 獲取密鑰別名
        */
        /*
        * 2.2. 獲取待哈希的數據
        */
        char tmpInData[] = "HMAC_MAC_INDATA_1";
        struct OH_Huks_Blob inData = { (uint32_t)strlen(tmpInData), (uint8_t *)tmpInData };
        uint8_t cipher[HMAC_COMMON_SIZE] = {0};
        struct OH_Huks_Blob hashText = {HMAC_COMMON_SIZE, cipher};
        /*
        * 2.3. 調用initSession獲取handle
        */
        /*
        * 2.4. 調用finishSession獲取哈希后的內容
        */
        ohResult = HksHmacTest(&keyAlias, hmacParamSet, &inData, &hashText);
        if (ohResult.errorCode != OH_HUKS_SUCCESS) {
            break;
        }
    } while (0);
    OH_Huks_FreeParamSet(&hmacParamSet);
}

審核編輯 黃宇