SM4采用OFB模式进行加解密

import cryptoFramework from '@ohos.security.cryptoFramework'; 
import { BusinessError } from '@ohos.base'; 
import data from '@ohos.telephony.data'; 
import buffer from '@ohos.buffer'; 
  
@Entry 
@Component 
struct Sm4ByOFB { 
@State message: string = 'Hello World' 
@State text:string=''; 
@State decryptRes:string=''; 
build() { 
  Row() { 
    Column() { 
      TextInput() 
        .border({ 
          width:1 
        }) 
        .margin({top:0}) 
        .width(240) 
        .height(50) 
        .backgroundColor(Color.Pink) 
        .onChange(result=>{ 
          this.text=result; 
        }) 
      Button('加密') 
        .fontSize(50) 
        .fontWeight(FontWeight.Bold) 
        .margin(20) 
        .onClick(()=>{ 
          SM4OfbToEncrypt(this.text) 
          AlertDialog.show({message:'加密成功'}) 
        }) 
      Button('解密') 
        .fontSize(50) 
        .fontWeight(FontWeight.Bold) 
        .margin(20) 
        .onClick(async ()=>{ 
          this.decryptRes=await SM4OfbToDecrypt(); 
        }) 
      Text(`${this.decryptRes}`) 
        .border({ 
          width:1 
        }) 
        .margin({top:20}) 
        .width(240) 
        .height(50) 
        .backgroundColor(Color.Orange) 
    } 
    .width('100%') 
  } 
  .height('100%') 
} 
} 
  
// Convert strings in plaintext into byte streams. 
// 字符串转成字节流 
function stringToUint8Array(str: string) { 
return new Uint8Array(buffer.from(str,'utf-8').buffer); 
} 
// 字节流转成可理解的字符串 
function uint8ArrayToString(array:Uint8Array) { 
// 将UTF-8编码转换成Unicode编码 
let out: string = ""; 
let index: number = 0; 
let len: number = array.length; 
while (index < len) { 
  let character = array[index++]; 
  switch(character >> 4) { 
    case 0: 
    case 1: 
    case 2: 
    case 3: 
    case 4: 
    case 5: 
    case 6: 
    case 7: 
      out += String.fromCharCode(character); 
      break; 
    case 12: 
    case 13: 
      out += String.fromCharCode(((character & 0x1F) << 6) | (array[index++] & 0x3F)); 
      break; 
    case 14: 
      out += String.fromCharCode(((character & 0x0F) << 12) | ((array[index++] & 0x3F) << 6) | ((array[index++] & 0x3F) << 0)); 
      break; 
    default: 
      break; 
  } 
} 
return out; 
} 
  
  
let sm4Generator = cryptoFramework.createSymKeyGenerator('SM4_128'); 
let promiseSymKey = sm4Generator.generateSymKey(); 
let res:cryptoFramework.DataBlob; 
// SM4 OFB加密 
async function SM4OfbToEncrypt(plainText:string) { 
let cipher = cryptoFramework.createCipher("SM4_128|OFB|PKCS7"); 
let input: cryptoFramework.DataBlob = { data: stringToUint8Array(plainText) }; 
let cipherData: cryptoFramework.DataBlob; 
let key: cryptoFramework.SymKey; 
  
key=await promiseSymKey 
await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE,key,null) 
cipherData=await cipher.doFinal(input) 
res=cipherData 
console.log("cipherData"+res) 
  
return res; 
} 
  
let result:cryptoFramework.DataBlob; 
  
async function SM4OfbToDecrypt(){ 
let sm4Generator = cryptoFramework.createSymKeyGenerator('SM4_128'); 
let decoder = cryptoFramework.createCipher("SM4_128|OFB|PKCS7"); 
await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE,await promiseSymKey,null) 
result=await decoder.doFinal(res) 
let mes=uint8ArrayToString(result.data) 
console.log("res11111"+mes); 
return mes; 
}