鸿蒙开发：Universal Keystore Kit（密钥管理服务）【密钥派生(ArkTS)】

密钥派生(ArkTS)

以HKDF256密钥为例，完成密钥派生。具体的场景介绍及支持的算法规格。

开发步骤

生成密钥

指定密钥别名。
初始化密钥属性集，可指定参数HUKS_TAG_DERIVED_AGREED_KEY_STORAGE_FLAG（可选），用于标识基于该密钥派生出的密钥是否由HUKS管理。
- 当TAG设置为HUKS_STORAGE_ONLY_USED_IN_HUKS时，表示基于该密钥派生出的密钥，由HUKS管理，可保证派生密钥全生命周期不出安全环境。
- 当TAG设置为HUKS_STORAGE_KEY_EXPORT_ALLOWED时，表示基于该密钥派生出的密钥，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，表示基于该密钥派生出的密钥，即可由HUKS管理，也可返回给调用方管理，业务可在后续派生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。
调用[generateKeyItem]生成密钥，具体请参考[密钥生成]。

除此之外，开发者也可以参考[密钥导入]，导入已有的密钥。

密钥派生

获取密钥别名、指定对应的属性参数HuksOptions。

可指定参数HUKS_TAG_DERIVED_AGREED_KEY_STORAGE_FLAG（可选），用于标识派生得到的密钥是否由HUKS管理。

生成	派生	规格
HUKS_STORAGE_ONLY_USED_IN_HUKS	HUKS_STORAGE_ONLY_USED_IN_HUKS	密钥由HUKS管理
HUKS_STORAGE_KEY_EXPORT_ALLOWED	HUKS_STORAGE_KEY_EXPORT_ALLOWED	密钥返回给调用方管理
未指定TAG具体值	HUKS_STORAGE_ONLY_USED_IN_HUKS	密钥由HUKS管理
未指定TAG具体值	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	密钥返回给调用方管理

注：派生时指定的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。

调用[initSession]初始化密钥会话，并获取会话的句柄handle。
调用[updateSession]更新密钥会话。
调用[finishSession]结束密钥会话，完成派生。

删除密钥

当密钥废弃不用时，需要调用[deleteKeyItem]删除密钥，具体请参考[密钥删除]

/*
 * 以下以HKDF256密钥的Promise操作使用为例
 */
import { huks } from '@kit.UniversalKeystoreKit';

/*
 * 确定密钥别名和封装密钥属性参数集
 */
let srcKeyAlias = "hkdf_Key";
let deriveHkdfInData = "deriveHkdfTestIndata";
let handle: number;
let finishOutData: Uint8Array;
let HuksKeyDeriveKeySize = 32;
/* 集成生成密钥参数集 */
let properties: Array<huks.HuksParam> = [
  {
    tag: huks.HuksTag.HUKS_TAG_ALGORITHM,
    value: huks.HuksKeyAlg.HUKS_ALG_AES,
  }, {
  tag: huks.HuksTag.HUKS_TAG_PURPOSE,
  value: huks.HuksKeyPurpose.HUKS_KEY_PURPOSE_DERIVE,
}, {
  tag: huks.HuksTag.HUKS_TAG_DIGEST,
  value: huks.HuksKeyDigest.HUKS_DIGEST_SHA256,
}, {
  tag: huks.HuksTag.HUKS_TAG_KEY_SIZE,
  value: huks.HuksKeySize.HUKS_AES_KEY_SIZE_128,
}, {
  tag: huks.HuksTag.HUKS_TAG_DERIVED_AGREED_KEY_STORAGE_FLAG,
  value: huks.HuksKeyStorageType.HUKS_STORAGE_ONLY_USED_IN_HUKS,
}];

let huksOptions: huks.HuksOptions = {
  properties: properties,
  inData: new Uint8Array(new Array())
}
/* 集成init时密钥参数集 */
let initProperties: Array<huks.HuksParam> = [{
  tag: huks.HuksTag.HUKS_TAG_ALGORITHM,
  value: huks.HuksKeyAlg.HUKS_ALG_HKDF,
}, {
  tag: huks.HuksTag.HUKS_TAG_PURPOSE,
  value: huks.HuksKeyPurpose.HUKS_KEY_PURPOSE_DERIVE,
}, {
  tag: huks.HuksTag.HUKS_TAG_DIGEST,
  value: huks.HuksKeyDigest.HUKS_DIGEST_SHA256,
}, {
  tag: huks.HuksTag.HUKS_TAG_DERIVE_KEY_SIZE,
  value: HuksKeyDeriveKeySize,
}];

let initOptions: huks.HuksOptions = {
  properties: initProperties,
  inData: new Uint8Array(new Array())
}
/* 集成finish时密钥参数集 */
let finishProperties: Array<huks.HuksParam> = [{
  tag: huks.HuksTag.HUKS_TAG_DERIVED_AGREED_KEY_STORAGE_FLAG,
  value: huks.HuksKeyStorageType.HUKS_STORAGE_ONLY_USED_IN_HUKS,
}, {
  tag: huks.HuksTag.HUKS_TAG_IS_KEY_ALIAS,
  value: true,
}, {
  tag: huks.HuksTag.HUKS_TAG_ALGORITHM,
  value: huks.HuksKeyAlg.HUKS_ALG_AES,
}, {
  tag: huks.HuksTag.HUKS_TAG_KEY_SIZE,
  value: huks.HuksKeySize.HUKS_AES_KEY_SIZE_256,
}, {
  tag: huks.HuksTag.HUKS_TAG_PURPOSE,
  value:
  huks.HuksKeyPurpose.HUKS_KEY_PURPOSE_ENCRYPT |
  huks.HuksKeyPurpose.HUKS_KEY_PURPOSE_DECRYPT,
}, {
  tag: huks.HuksTag.HUKS_TAG_DIGEST,
  value: huks.HuksKeyDigest.HUKS_DIGEST_NONE,
}, {
  tag: huks.HuksTag.HUKS_TAG_KEY_ALIAS,
  value: StringToUint8Array(srcKeyAlias),
}, {
  tag: huks.HuksTag.HUKS_TAG_PADDING,
  value: huks.HuksKeyPadding.HUKS_PADDING_NONE,
}, {
  tag: huks.HuksTag.HUKS_TAG_BLOCK_MODE,
  value: huks.HuksCipherMode.HUKS_MODE_ECB,
}];
let finishOptions: huks.HuksOptions = {
  properties: finishProperties,
  inData: new Uint8Array(new Array())
}

function StringToUint8Array(str: String) {
  let arr: number[] = new Array();
  for (let i = 0, j = str.length; i < j; ++i) {
    arr.push(str.charCodeAt(i));
  }
  return new Uint8Array(arr);
}

class throwObject {
  isThrow = false;
}

function generateKeyItem(keyAlias: string, huksOptions: huks.HuksOptions, throwObject: throwObject) {
  return new Promise<void>((resolve, reject) => {
    try {
      huks.generateKeyItem(keyAlias, huksOptions, (error, data) => {
        if (error) {
          reject(error);
        } else {
          resolve(data);
        }
      });
    } catch (error) {
      throwObject.isThrow = true;
      throw (error as Error);
    }
  });
}

async function publicGenKeyFunc(keyAlias: string, huksOptions: huks.HuksOptions) {
  console.info(`enter promise generateKeyItem`);
  let throwObject: throwObject = { isThrow: false };
  try {
    await generateKeyItem(keyAlias, huksOptions, throwObject)
      .then((data) => {
        console.info(`promise: generateKeyItem success, data = ${JSON.stringify(data)}`);
      })
      .catch((error: Error) => {
        if (throwObject.isThrow) {
          throw (error as Error);
        } else {
          console.error(`promise: generateKeyItem failed, ${JSON.stringify(error)}`);
        }
      });
  } catch (error) {
    console.error(`promise: generateKeyItem input arg invalid, ${JSON.stringify(error)}`);
  }
}

function initSession(keyAlias: string, huksOptions: huks.HuksOptions, throwObject: throwObject) {
  return new Promise<huks.HuksSessionHandle>((resolve, reject) => {
    try {
      huks.initSession(keyAlias, huksOptions, (error, data) => {
        if (error) {
          reject(error);
        } else {
          resolve(data);
        }
      });
    } catch (error) {
      throwObject.isThrow = true;
      throw (error as Error);
    }
  });
}

async function publicInitFunc(keyAlias: string, huksOptions: huks.HuksOptions) {
  console.info(`enter promise doInit`);
  let throwObject: throwObject = { isThrow: false };
  try {
    await initSession(keyAlias, huksOptions, throwObject)
      .then((data) => {
        console.info(`promise: doInit success, data = ${JSON.stringify(data)}`);
        handle = data.handle;
      })
      .catch((error: Error) => {
        if (throwObject.isThrow) {
          throw (error as Error);
        } else {
          console.error(`promise: doInit failed, ${JSON.stringify(error)}`);
        }
      });
  } catch (error) {
    console.error(`promise: doInit input arg invalid, ${JSON.stringify(error)}`);
  }
}

function updateSession(handle: number, huksOptions: huks.HuksOptions, throwObject: throwObject) {
  return new Promise<huks.HuksOptions>((resolve, reject) => {
    try {
      huks.updateSession(handle, huksOptions, (error, data) => {
        if (error) {
          reject(error);
        } else {
          resolve(data);
        }
      });
    } catch (error) {
      throwObject.isThrow = true;
      throw (error as Error);
    }
  });
}

async function publicUpdateFunc(handle: number, huksOptions: huks.HuksOptions) {
  console.info(`enter promise doUpdate`);
  let throwObject: throwObject = { isThrow: false };
  try {
    await updateSession(handle, huksOptions, throwObject)
      .then((data) => {
        console.info(`promise: doUpdate success, data = ${JSON.stringify(data)}`);
      })
      .catch((error: Error) => {
        if (throwObject.isThrow) {
          throw (error as Error);
        } else {
          console.error(`promise: doUpdate failed, ${JSON.stringify(error)}`);
        }
      });
  } catch (error) {
    console.error(`promise: doUpdate input arg invalid, ${JSON.stringify(error)}`);
  }
}

function finishSession(handle: number, huksOptions: huks.HuksOptions, throwObject: throwObject) {
  return new Promise<huks.HuksReturnResult>((resolve, reject) => {
    try {
      huks.finishSession(handle, huksOptions, (error, data) => {
        if (error) {
          reject(error);
        } else {
          resolve(data);
        }
      });
    } catch (error) {
      throwObject.isThrow = true;
      throw (error as Error);
    }
  });
}

async function publicFinishFunc(handle: number, huksOptions: huks.HuksOptions) {
  console.info(`enter promise doFinish`);
  let throwObject: throwObject = { isThrow: false };
  try {
    await finishSession(handle, huksOptions, throwObject)
      .then((data) => {
        finishOutData = data.outData as Uint8Array;
        console.info(`promise: doFinish success, data = ${JSON.stringify(data)}`);
      })
      .catch((error: Error) => {
        if (throwObject.isThrow) {
          throw (error as Error);
        } else {
          console.error(`promise: doFinish failed, ${JSON.stringify(error)}`);
        }
      });
  } catch (error) {
    console.error(`promise: doFinish input arg invalid, ${JSON.stringify(error)}`);
  }
}

function deleteKeyItem(keyAlias: string, huksOptions: huks.HuksOptions, throwObject: throwObject) {
  return new Promise<void>((resolve, reject) => {
    try {
      huks.deleteKeyItem(keyAlias, huksOptions, (error, data) => {
        if (error) {
          reject(error);
        } else {
          resolve(data);
        }
      });
    } catch (error) {
      throwObject.isThrow = true;
      throw (error as Error);
    }
  });
}

async function publicDeleteKeyFunc(keyAlias: string, huksOptions: huks.HuksOptions) {
  console.info(`enter promise deleteKeyItem`);
  let throwObject: throwObject = { isThrow: false };
  try {
    await deleteKeyItem(keyAlias, huksOptions, throwObject)
      .then((data) => {
        console.info(`promise: deleteKeyItem key success, data = ${JSON.stringify(data)}`);
      })
      .catch((error: Error) => {
        if (throwObject.isThrow) {
          throw (error as Error);
        } else {
          console.error(`promise: deleteKeyItem failed, ${JSON.stringify(error)}`);
        }
      });
  } catch (error) {
    console.error(`promise: deleteKeyItem input arg invalid, ${JSON.stringify(error)}`);
  }
}

async function testDerive() {
  /* 生成密钥 */
  await publicGenKeyFunc(srcKeyAlias, huksOptions);
  /* 进行派生操作 */
  await publicInitFunc(srcKeyAlias, initOptions);
  initOptions.inData = StringToUint8Array(deriveHkdfInData);
  await publicUpdateFunc(handle, initOptions);
  await publicFinishFunc(handle, finishOptions);
  await publicDeleteKeyFunc(srcKeyAlias, huksOptions);
}