Generating a Key (C/C++)
This topic walks you through on how to randomly generate a key with the ECC algorithm. For details about the scenarios and supported algorithms, see Supported Algorithms.
NOTE Key aliases must not contain sensitive information, such as personal data.
Linking the Dynamic Library in the CMake Script
target_link_libraries(entry PUBLIC libhuks_ndk.z.so)
How to Develop
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Specify the key alias. For details about the naming rules, see Key Generation Overview and Algorithm Specifications.
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Initialize the key property set. Construct paramSet using OH_Huks_InitParamSet, OH_Huks_AddParams, and OH_Huks_BuildParamSet.
The key property set must contain the OH_Huks_KeyAlg, OH_Huks_KeySize, and OH_Huks_KeyPurpose properties. Note that a key can have only one purpose, and the purpose specified during key generation must match the key purpose during usage. Otherwise, an exception occurs.
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Call OH_Huks_GenerateKeyItem and pass in the key alias and key property set to generate a key.
NOTE
If the service uses the same key alias to call the HUKS API to generate a key again, HUKS will generate a new key and overwrite the historical key file.
/* Generate an ECC key. */
#include "huks/native_huks_api.h"
#include "huks/native_huks_param.h"
#include "napi/native_api.h"
#include <cstring>
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;
}
struct OH_Huks_Param g_testGenerateKeyParam[] = {{.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 napi_value GenerateKey(napi_env env, napi_callback_info info)
{
/* 1. Set the key alias. */
const char *alias = "test_generate";
struct OH_Huks_Blob aliasBlob = {.size = (uint32_t)strlen(alias), .data = (uint8_t *)alias};
struct OH_Huks_ParamSet *testGenerateKeyParamSet = nullptr;
struct OH_Huks_Result ohResult;
do {
/* 2. Initialize the key property set. */
ohResult = InitParamSet(&testGenerateKeyParamSet, g_testGenerateKeyParam,
sizeof(g_testGenerateKeyParam) / sizeof(OH_Huks_Param));
if (ohResult.errorCode != OH_HUKS_SUCCESS) {
break;
}
/* 3. Generate a key. */
ohResult = OH_Huks_GenerateKeyItem(&aliasBlob, testGenerateKeyParamSet, nullptr);
} while (0);
OH_Huks_FreeParamSet(&testGenerateKeyParamSet);
napi_value ret;
napi_create_int32(env, ohResult.errorCode, &ret);
return ret;
}