[Question]: What is a reason for androidSdkVersion = 19 ?

[isabsent]

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I have found only a few try-catch blocks with multy-catch syntax in your code. Are there other reasons to keep androidSdkVersion = 19 or it can be lowered to 14 for example?

[hierynomus]

What would be the reason for downgrading it?

[isabsent]

Our file manager supports devices starting from SDK 14.

[hierynomus]

If it is possible to use a lower version without code changes I'm fine, if not, then you're out of luck

[chrisgch]

I'm in a similar situation. When you use menu Analyze -> Inspect code in Android Studio, you can see which functions need SDK 19:

1. GCMParameterSpec, BCAEADCipherFactory need SDK 19. You can use SMB3 on older SDK versions, but only without encryption.
2. Some classes use AutoClosable, which is officially supported only on SDK 19, but is part of Android since SDK 14: https://issuetracker.google.com/issues/36999599?pli=1#comment4
3. Objects.hash in ASN1Tag isn't called unless you put ASN1Tag structures in a hash map or similar
4. The class ASN1BitString is not called from elsewhere
5. I have removed the following classes not used on Android: smbj/auth/ExtendedGSSContext.java smbj/auth/GSSAuthenticationContext.java smbj/auth/SpnegoAuthenticator.java smbj/transport/tcp/async/AsyncDirectTcpTransport.java smbj/transport/tcp/async/AsyncDirectTcpTransportFactory.java smbj/transport/tcp/async/AsyncPacketReader.java smbj/transport/tcp/async/PacketBufferReader.java

In conclusion, you can use smbj on SDK 14 and newer without encryption, and on SDK 19 and newer with encryption. To use it without encryption, either disable SMB3, or open Session.java and remove the following line: encryptData |= (sessionContext.getEncryptionKey() != null && connection.getConnectionContext().clientPrefersEncryption()); This enabled encryption even when the user has disabled it, but the server reports that it would prefer encryption.

[isabsent]

Thanks a lot!!!

[hierynomus]

In conclusion, you can use smbj on SDK 14 and newer without encryption, and on SDK 19 and newer with encryption. To use it without encryption, either disable SMB3, or open Session.java and remove the following line: encryptData |= (sessionContext.getEncryptionKey() != null && connection.getConnectionContext().clientPrefersEncryption()); This enabled encryption even when the user has disabled it, but the server reports that it would prefer encryption.

That is in line with the spec, removing that line basically makes it non-SMB3 compatible. So you're better off disabling SMB3 in the config in that case.

[chrisgch]

In my app, the user can check/uncheck encrypted transfers. It only forces encrypted transfers when the server requires them. This way the user can choose between more security and higher transfer speeds, not the server.