RemoteDiskImager

Pull an image of a linux block device via pure SSH

Idea

The problem I saught to solve here, was to create a disk image of a Raspberry Pi's SDCard without disassembling its casing. I do have sudo privileges but there are some essetial tools and privileges missing thus I restricted myself to work with this:

• Use a single SSH connection
• No SFTP or port forwarding
• Directly consuming the output of dd
• Collecting found block deviced with lsblk

Also, the tool should be easy used by inexperienced users. Thus, the tool should be a wizard leading through what is needed.

The connection is usually initialized with a lower privileged user who has to evivate to su privileges. For this, the tool has to support su and sudo due to the different server configurations.

Usage (CLI version)

RemoteDiskImager [options] <user>@<host>[:<path>] <target>

Options:
  -p, --port <port>            SSH port number (default: 22)
  -P, --password <password>    SSH or certification password
  -I, --cert <file>            SSH server certificate file
  -s, --su                     Use 'su' to gain root privilege
  -d, --sudo                   Use 'sudo -s' to gain root privilege
  -S, --su-password <password> Password for 'su' or 'sudo'
  -b, --block-size <size>      Block size (default: 8M)
  -c, --count <count>          Number of blocks to copy (default: all)
  -h, -?, --help               Show this help message

To start the tool with minimal options, just give it <user>, <host> and <target>, e.g.:

RemoteDiskImager testuser@192.168.0.1 C:\backup\test.img

You can also use a not detected block device or a simple file just by passing it, e.g. getting 10 * 10MB of randon data:

RemoteDiskImager -b 10M -c 10 testuser@192.168.0.1:/dev/random C:\backup\random.img

To use a certification file to connect, specify it via -I <file>>. The tool will try to open it and if it fails will ask for its passphrase which you can also pass via -P <password>:

RemoteDiskImager -I C:\Users\test\.ssh\testuser.ppk testuser@192.168.0.1 C:\backup\test.img

To use su to elivate privileges to access a block device, pass the -s parameter. The tool will ask for the su password individually or you can password via -S <passwork>.

RemoteDiskImager -s testuser@192.168.0.1 C:\backup\test.img

The same is true for the -d parameter to use sudo to elivate. It won't use the login password here so you'll have to specify it twice, leaving it empty will assume the passwort to be empty or NOPASSWD: being in place for dd.

Usage (UI version)

The UI version is a simple Windows Forms application. I uses the same logic, though, even using the same code. The CLI parameters can be useed to prefill the fields. The rest should be self-explanitory.

Dependencies

This tool relies heavily on SSH.NET.