HarmonyOS 已知RSA或者SM2私钥，如何生成ARKUI可用私钥对象

import crypto from '@ohos.security.cryptoFramework'; 
/** 
 * 将非对称加密字符串priKey转换为symKey对象 
 * @param privateKey字符串key 
 * @param symAlgName 秘钥规格 
 * @returns 
 */ 
static async convertPriKeyFromStr(privateKey: string, symAlgName: string) { 
  let symKeyBlob: crypto.DataBlob = { data: StrAndUintUtil.stringToByteArray(privateKey) }; 
  let aesGenerator = crypto.createAsyKeyGenerator(symAlgName); 
  let symKey = await aesGenerator.convertKey(null, symKeyBlob); 
  return symKey; 
} 
 
/** 
 * 字符串转换为Uint8Array数组 
 * @param str 字符串 
 * @returns Uint8Array数组 
 */ 
static stringToByteArray(str: string): Uint8Array { 
  const hexString = str.match(/.{1,2}/g); // 将字符串按每两个字符分割为数组 
  let arr = new Array<string>(); 
  hexString?.forEach((val) => { 
    arr.push(val); 
  }) 
  const byteArray: number[] = arr.map(byte => parseInt(byte, 16)); // 将每个十六进制字节转换为整数 
  return new Uint8Array(byteArray); 
}