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Server Message Block (SMB2, SMB3) implementation in Java

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smbj - SMB2/SMB3 client library for Java

To get started, have a look at one of the examples. Hopefully you will find the API pleasant to work with :)

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Getting SMBJ

To get SMBJ, you have two options:

  1. Add a dependency to SMBJ to your project.

  2. Build SMBJ yourself.

And, if you want, you can also run the SMBJ examples.

Binary releases of SMBJ are not provided here, but you can download it straight from the Maven Central repository if you want to.

Examples

A - Listing Files on a Share/Folder

    SMBClient client = new SMBClient();

    try (Connection connection = client.connect("SERVERNAME")) {
        AuthenticationContext ac = new AuthenticationContext("USERNAME", "PASSWORD".toCharArray(), "DOMAIN");
        Session session = connection.authenticate(ac);

        // Connect to Share
        try (DiskShare share = (DiskShare) session.connectShare("SHARENAME")) {
            for (FileIdBothDirectoryInformation f : share.list("FOLDER", "*.TXT")) {
                System.out.println("File : " + f.getFileName());
            }
        }
    }

B - Deleting a file

    SMBClient client = new SMBClient(config);

    try (Connection connection = client.connect("SERVERNAME")) {
        AuthenticationContext ac = new AuthenticationContext("USERNAME", "PASSWORD".toCharArray(), "DOMAIN");
        Session session = connection.authenticate(ac);

        // Connect to Share
        try (DiskShare share = (DiskShare) session.connectShare("SHARENAME")) {
            share.rm("FILE");
        }
    }

C - Adjusting Timeout and Socket Timeout

    SmbConfig config = SmbConfig.builder()
            .withTimeout(120, TimeUnit.SECONDS) // Timeout sets Read, Write, and Transact timeouts (default is 60 seconds)
            .withSoTimeout(180, TimeUnit.SECONDS) // Socket Timeout (default is 0 seconds, blocks forever)
            .build();

    SMBClient client = new SMBClient(config);

    try (Connection connection = client.connect("SERVERNAME")) {
        AuthenticationContext ac = new AuthenticationContext("USERNAME", "PASSWORD".toCharArray(), "DOMAIN");
        Session session = connection.authenticate(ac);

        // Connect to Share
        try (DiskShare share = (DiskShare) session.connectShare("SHARENAME")) {
            ...
        }
    }

Frequently Asked Questions

When I run my code I get an SMBApiException with the message STATUS_…​ (0x…​). What am I doing wrong?

SMBJ is a low-level SMB client implementation. Most file/directory operations result in a request being sent to the SMB server. If the server responds to these requests with an error SMBJ will pass this error back to the calling code via an exception. The STATUS_…​ value is the error code the server sent back to the client.

It is considered out of scope for the SMBJ project to document each and every possible error condition that may occur when using the SMB protocol. Detailed information on these errors can be found in the SMB specification and the error code table. Some common errors are described below.

When I try to open a file or directory my code fails with STATUS_ACCESS_DENIED. How can I fix this?

This error means that the file access you’ve requested (the set of AccessMask values) is not being allowed by the server for the user account you used to log in to the server. Why this happens exactly depends on the precise set of AccessMask values you specified and the access control list that has been set on the file or directory in question.

To resolve this, reduce the set of AccessMask values down to just the access that you need. For instance, if you only want to read the contents of the file use FILE_READ_DATA instead of something more broad like GENERIC_READ or GENERIC_ALL.

The special MAXIMUM_ALLOWED value can be used to ask the server to grant the full set of permissions that are allowed by the access control list. You can then query the FileAccessInformation information class to determine which set of permissions was granted by the server.

For more details please refer to the documentation on creating and opening files on MSDN.

When I try to open a file or directory my code fails with STATUS_SHARING_VIOLATION. What does this mean?

A sharing violation error means that some other process has already opened the file or directory in question in a way that is incompatible with how you’re trying to open it. This could be your own program, a different program running on your machine, a program running on a different client machine or even a process on the SMB server itself like an indexing or virus scanning service.

The SMB protocol does allow multiple clients to open the same file at the same time, but they need to cooperate when doing so. This is controlled by the set of SMB2ShareAccess values that are passed to the open file calls. When this set is empty, the SMB client requests exclusive access to the file. Passing one or more values indicates that other clients may open the file for the specified operations as well. For instance, if you open the file with only FILE_SHARE_READ and successfully open the file, then other clients may open the file for reading as well. If another client tries to open the file for writing, it will fail at that point with STATUS_SHARING_VIOLATION as long as you have the file open.

For more details please refer to the documentation on creating and opening files on MSDN.

Depending on SMBJ

If you’re building your project using Maven, you can add the following dependency to the pom.xml:

<dependency>
  <groupId>com.hierynomus</groupId>
  <artifactId>smbj</artifactId>
  <version>0.13.0</version>
</dependency>

If your project is built using another build tool that uses the Maven Central repository, translate this dependency into the format used by your build tool.

Building SMBJ

  1. Clone the SMBJ repository.

  2. Ensure you have Java7 installed with the Unlimited strength Java Cryptography Extensions (JCE).

  3. Run the command ./gradlew clean build.

Changelog

0.13.0 (2023-11-20)

  • Use FILE_OPEN_IF if no SMB2CreateDisposition provided (Fixes #786)

  • Integration tests rewritten to JUnit Jupiter and TestContainers

  • Use BufferedInputStream to read Socket (Merged #795)

  • Clear serverList when last connection closed (Merged #719)

0.12.2 (2023-08-07)

  • Added missing applicationKey getter to SessionContext (Merged #776)

  • Fix error with anonymous authentication (Fixes #779)

0.12.1 (2023-07-13)

  • Fix NPE when using SpnegoAuthenticator (Fixes #775)

0.12.0 (2023-07-06)

  • Support signing and sealing of NTLM authentication

  • Reworked NTLM authentication (Fixes #653)

  • Upgraded Gradle to 8.2

  • Add support for reading / writing NIO ByteBuffers

  • Ensure path is set for rmdir to prevent accidents (Fixes #756)

  • Ensure we call flip() on Buffer to avoid Java8/9 compatibility issues (Fixes #705)

  • Do not send SNB2EncryptionCapabilities if the withEncryptData is set to false (Fixes #747)

  • Added Implementation-Version and Implementation-Name to MANIFEST.MF (Fixes #743)

  • Bytes written by the SMB2Writer are now returned as long, correctly reporting on files >2GB (Fixes #740)

  • Reduce the amount of locking in Connection and DirectTcpTransport

  • Fixed Cannot resolve path exception in DFS by specifying the correct TargetHint (Fixes #419)

  • Fixed ClassCastException in TargetInfo (Fixes #712)

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Server Message Block (SMB2, SMB3) implementation in Java

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