pkg smb

pkg/smb - SMB2/3 Client

Full SMB2/3 client supporting NTLM and Kerberos authentication, share enumeration, file operations, and named pipe access.

Types

Client

type Client struct {
    Session *smb2.Session
    Target  session.Target
    Creds   *session.Credentials
}

PipeAccess

type PipeAccess int

const (
    PipeAccessReadWrite PipeAccess = iota
    PipeAccessRead
    PipeAccessWrite
)

Constructor

func NewClient(target session.Target, creds *session.Credentials) *Client

Connection Methods

Method	Signature	Description
Connect	() error	Establish SMB session with auto-negotiated auth (NTLM or Kerberos)
Close	()	Logoff session, unmount shares, close connection
GetSessionKey	() []byte	Returns the SMB session key
GetDNSHostName	() string	Server's DNS hostname from NTLM challenge
GetDNSTreeName	() string	Forest DNS name from NTLM challenge

Share Operations

Method	Signature	Description
ListShares	() ([]string, error)	Enumerate available shares (sorted)
UseShare	(name string) error	Mount a share as the active working share

File Operations

Method	Signature	Description
Ls	(dir string) ([]os.FileInfo, error)	List files in a directory
Cd	(dir string) error	Change current directory
Get	(remoteFile, localFile string) error	Download a file
Put	(localFile, remoteFile string) error	Upload a file
Cat	(file string) (string, error)	Read file contents as string
Mkdir	(dir string) error	Create a directory
Rmdir	(dir string) error	Remove a directory
Rm	(file string) error	Delete a file
Rename	(oldPath, newPath string) error	Rename/move a file
Mget	(pattern string) error	Download files matching a glob pattern
GetCurrentPath	() string	Return current working directory

Recursive Traversal

type TreeWalkFunc func(path string, info os.FileInfo, err error) error

func (c *Client) Tree(root string, fn TreeWalkFunc) error

client.UseShare("C$")
client.Tree("Users", func(path string, info os.FileInfo, err error) error {
    if err != nil {
        return nil
    }
    fmt.Printf("%s (%d bytes)\n", path, info.Size())
    return nil
})

Named Pipe Operations

Method	Signature	Description
OpenPipe	(name string) (*smb2.File, error)	Open a named pipe (mounts IPC$ automatically)
OpenPipeWithAccess	(name string, access PipeAccess) (*smb2.File, error)	Open with specified access mode

Named pipes are the transport layer for DCE/RPC over SMB.

Example: Enumerate Shares

package main

import (
    "fmt"
    "gopacket/pkg/session"
    "gopacket/pkg/smb"
)

func main() {
    target := session.Target{Host: "10.0.0.5", Port: 445}
    creds := &session.Credentials{
        Domain:   "CORP",
        Username: "admin",
        Password: "Password1",
    }

    client := smb.NewClient(target, creds)
    defer client.Close()

    if err := client.Connect(); err != nil {
        fmt.Printf("[-] %v\n", err)
        return
    }

    shares, err := client.ListShares()
    if err != nil {
        fmt.Printf("[-] %v\n", err)
        return
    }

    for _, share := range shares {
        fmt.Printf("[+] \\\\%s\\%s\n", target.Host, share)
    }
}

Example: Kerberos Authentication

creds := &session.Credentials{
    Domain:      "CORP.LOCAL",
    Username:    "admin",
    UseKerberos: true,
    DCIP:        "10.0.0.1",
}
// Set KRB5CCNAME env var or place admin.ccache in CWD

client := smb.NewClient(session.Target{Host: "dc01.corp.local", Port: 445}, creds)
defer client.Close()
client.Connect() // Authenticates via Kerberos AP-REQ