Certainly! Here are the commands to create an encrypted DMG, mount it, copy files to it, and dismount it in macOS:

1. Create an Encrypted DMG

To create an encrypted DMG (Disk Image):

# Replace 'MyDiskImage' with your desired disk image name
hdiutil create -size 100m -encryption AES-256 -fs APFS -volname "MyDiskImage" MyDiskImage.dmg
  • Options:
    • -size 100m: Sets the size of the disk image to 100 MB. Adjust as needed.
    • -encryption AES-256: Specifies AES-256 encryption.
    • -fs APFS: Specifies the file system format (APFS in this example). You can use -fs HFS+ for HFS+ format.
    • -volname "MyDiskImage": Sets the volume name inside the disk image.

2. Mount Encrypted DMG

To mount the encrypted DMG:

hdiutil attach MyDiskImage.dmg
  • This command mounts the MyDiskImage.dmg file. The mounted volume will typically appear under /Volumes/MyDiskImage.

3. Copy Files to the Encrypted DMG

Once mounted, you can copy files to the encrypted DMG using standard cp commands:

cp /path/to/source/file.txt /Volumes/MyDiskImage/
  • Replace /path/to/source/file.txt with the path to the file you want to copy.

4. Dismount Encrypted DMG

To dismount (unmount) the encrypted DMG:

hdiutil detach /Volumes/MyDiskImage
  • This command unmounts the volume named MyDiskImage that was previously mounted from the MyDiskImage.dmg file.

Additional Considerations

  • File Permissions: Ensure appropriate permissions for accessing and modifying files within the encrypted DMG.
  • Encryption and Security: Use strong passwords and encryption standards (like AES-256) to secure your DMG files.
  • Automation: You can automate these steps using shell scripts for repetitive tasks.

These commands provide a streamlined approach to create, mount, manage files, and dismount encrypted DMG files in macOS, ensuring secure handling of sensitive data. Adjust parameters and paths based on your specific requirements and security policies.

Yes, you can mount a .dmg file into a specific directory, such as $HOME/encrypted, in macOS. Here's how you can achieve this:

Mounting the DMG into $HOME/encrypted

To mount the .dmg file into $HOME/encrypted, you can use the hdiutil command with the -mountpoint option:

# Replace 'MyDiskImage.dmg' with your actual disk image file name
hdiutil attach MyDiskImage.dmg -mountpoint ~/encrypted
  • This command mounts the MyDiskImage.dmg file and specifies ~/encrypted as the mount point (mount directory).

Example Workflow:

  1. Create an Encrypted DMG: Suppose you've already created an encrypted DMG named MyDiskImage.dmg using the appropriate hdiutil create command.

  2. Mounting with Specific Mount Point:

    hdiutil attach MyDiskImage.dmg -mountpoint ~/encrypted
    • This command mounts MyDiskImage.dmg into the directory ~/encrypted (which is equivalent to $HOME/encrypted).

  3. Accessing Mounted Volume: After mounting, the contents of the .dmg file will be accessible under ~/encrypted.

  4. Dismounting: To dismount the volume when you're done:

    hdiutil detach ~/encrypted
    • This command unmounts the volume mounted at ~/encrypted.

Notes:

  • Ensure that ~/encrypted exists before attempting to mount the DMG into it.
  • Adjust permissions (chmod, chown) as needed to ensure proper access to the mounted directory.
  • Replace MyDiskImage.dmg with the actual name and path of your .dmg file.

By specifying a specific mount point (-mountpoint) with hdiutil, you can control where the .dmg file is mounted in macOS, providing flexibility in managing encrypted volumes and their contents securely.