AES128 encryption and decryption sample code common to Android, iOS and Java

Preface

Mobile terminals are becoming more and more popular. During the development process, we will always encounter scenarios where we have to deal with mobile terminals, such as dealing with android and iOS. In order to make data interaction more secure, we need to encrypt the data for transmission.

This article will share with you the encryption and decryption of AES, the common AES encryption algorithm for Android and ios. You can directly integrate it into your own project. If the server interface is written in Java, the entire framework will be perfect. , If it is a backend interface written in .NET, it needs to be modified

IOS Encryption

/*加密方法*/
 (NSString *)AES256EncryptWithPlainText:(NSString *)plain {
 NSData *plainText = [plain dataUsingEncoding:NSUTF8StringEncoding];
 // ´key´ should be 32 bytes for AES256, will be null-padded otherwise
 char keyPtr[kCCKeySizeAES256 1]; // room for terminator (unused)
 bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)
   
 NSUInteger dataLength = [plainText length];
 
 size_t bufferSize = dataLength kCCBlockSizeAES128;
 void *buffer = malloc(bufferSize);
 bzero(buffer, sizeof(buffer));
  
 size_t numBytesEncrypted = 0;
  
 CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128,kCCOptionPKCS7Padding,
           [[NSData AESKeyForPassword:PASSWORD] bytes], kCCKeySizeAES256,
           ivBuff /* initialization vector (optional) */,
           [plainText bytes], dataLength, /* input */
           buffer, bufferSize, /* output */
           &numBytesEncrypted);
 if (cryptStatus == kCCSuccess) {
  NSData *encryptData = [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
  return [encryptData base64Encoding];
 }
  
 free(buffer); //free the buffer;
 return nil;
}

IOS Decryption

/*解密方法*/
 (NSString *)AES256DecryptWithCiphertext:(NSString *)ciphertexts{
  
 NSData *cipherData = [NSData dataWithBase64EncodedString:ciphertexts];
 // ´key´ should be 32 bytes for AES256, will be null-padded otherwise
 char keyPtr[kCCKeySizeAES256 1]; // room for terminator (unused)
 bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding)
   
 NSUInteger dataLength = [cipherData length];
  
 size_t bufferSize = dataLength kCCBlockSizeAES128;
 void *buffer = malloc(bufferSize);
   
 size_t numBytesDecrypted = 0;
 CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
           [[NSData AESKeyForPassword:PASSWORD] bytes], kCCKeySizeAES256,
           ivBuff ,/* initialization vector (optional) */
           [cipherData bytes], dataLength, /* input */
           buffer, bufferSize, /* output */
           &numBytesDecrypted);
  
 if (cryptStatus == kCCSuccess) {
  NSData *encryptData = [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
  return [[[NSString alloc] initWithData:encryptData encoding:NSUTF8StringEncoding] init];
 }
  
 free(buffer); //free the buffer;
 return nil;
}

Android Encryption

private byte[] encrypt(String cmp, SecretKey sk, IvParameterSpec IV,
  byte[] msg) {
 try {
  Cipher c = Cipher.getInstance(cmp);
  c.init(Cipher.ENCRYPT_MODE, sk, IV);
  return c.doFinal(msg);
 } catch (NoSuchAlgorithmException nsae) {
  Log.e("AESdemo", "no cipher getinstance support for " cmp);
 } catch (NoSuchPaddingException nspe) {
  Log.e("AESdemo", "no cipher getinstance support for padding " cmp);
 } catch (InvalidKeyException e) {
  Log.e("AESdemo", "invalid key exception");
 } catch (InvalidAlgorithmParameterException e) {
  Log.e("AESdemo", "invalid algorithm parameter exception");
 } catch (IllegalBlockSizeException e) {
  Log.e("AESdemo", "illegal block size exception");
 } catch (BadPaddingException e) {
  Log.e("AESdemo", "bad padding exception");
 }
 return null;
}

Android Decryption

private byte[] decrypt(String cmp, SecretKey sk, IvParameterSpec IV,
   byte[] ciphertext) {
 try {
  Cipher c = Cipher.getInstance(cmp);
  c.init(Cipher.DECRYPT_MODE, sk, IV);
  return c.doFinal(ciphertext);
 } catch (NoSuchAlgorithmException nsae) {
  Log.e("AESdemo", "no cipher getinstance support for " cmp);
 } catch (NoSuchPaddingException nspe) {
  Log.e("AESdemo", "no cipher getinstance support for padding " cmp);
 } catch (InvalidKeyException e) {
  Log.e("AESdemo", "invalid key exception");
 } catch (InvalidAlgorithmParameterException e) {
  Log.e("AESdemo", "invalid algorithm parameter exception");
 } catch (IllegalBlockSizeException e) {
  Log.e("AESdemo", "illegal block size exception");
 } catch (BadPaddingException e) {
  Log.e("AESdemo", "bad padding exception");
  e.printStackTrace();
 }
 return null;
}

Summary

The above is the entire content of this article. I hope the content of this article can be helpful to all developers. If you have any questions, you can leave a message to communicate.

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