Why Bad state: IV is required, after upgrade from 4.0.2 to 5.0.0.

[SevenCho]

Upgrade from 4.0.4 to 5.0.0, the original encryption algorithm is wrong。

Mode: ECB Padding: PKCS7 IV: No

    final key = Key(Uint8List.fromList(keyBytes));
    final encrypter = Encrypter(AES(key, mode: AESMode.ecb, padding: 'PKCS7'));
    final encrypted = encrypter.encryptBytes(input);

• Now there is an IV error. I checked the stack and found that it is because the IV is null, but I don't need the IV parameter at all.
• The source code that caused the error：

@override
  Encrypted encrypt(Uint8List bytes, {IV? iv}) {
    if (iv == null) {
      throw StateError('IV is required.');
    }

    if (_streamCipher != null) {
      _streamCipher!
        ..reset()
        ..init(true, _buildParams(iv));

      return Encrypted(_streamCipher!.process(bytes));
    }

[leocavalcante]

@are the ECB mode doesn't require an IV. Do you have fresh in mind why this check? Can I just remove it?

[are]

That was because the _buildParams method uses the ParametersWithIV class that requires iv to be not null, so the check was added to make sure its supplied.

[leocavalcante]

Right, thanks.

@SevenCho can you workaround this by now please giving a meaningless IV?

final encrypted = encrypter.encryptBytes(input, iv: IV.fromLength(16));

I will be thinking on a proper strategy to handle this.

[SevenCho]

Right, thanks.

@SevenCho can you workaround this by now please giving a meaningless IV?

final encrypted = encrypter.encryptBytes(input, iv: IV.fromLength(16));

I will be thinking on a proper strategy to handle this.

Giving a meaningless IV that works. I tried different meaningless IVs. but I don’t know if this will cause potential problems.

final iv = IV.fromBase16("");
final iv = IV.fromLength(16);

[leocavalcante]

Don't worry, for ECB it will just be ignored.

[hiashutoshsingh]

Please fix this, ECB does not require an IV. So supplying an IV should not be required. Also worse is that the function still fails if you provide null, even though signature specifically allows it:

https://pub.dev/documentation/encrypt/latest/encrypt/Encrypter/encrypt.html

but in my case it still giving an error

[wbusey0]

Right, thanks.

@SevenCho can you workaround this by now please giving a meaningless IV?

final encrypted = encrypter.encryptBytes(input, iv: IV.fromLength(16));

I will be thinking on a proper strategy to handle this.

I think moving the iv == null check into the _buildParams method right before the return would solve this?