Export Primary Secret Key With All Subkeys

Verify Your Primary "Certify" Key Is Available

For advanced users who deleted their "certify" capability secret key, you need to restore it back for key creations. You can verify it by using the following command:

$ gpg --list-secret-keys

Example:

$ gpg --list-secret-keys

...

---------------------------

sec   rsa4096 2020-01-10 [C]

      AC51A10307C10B2A4BB1C89AF5EF57A0FB4EF0EF

uid           [ultimate] "Shotgun" John, Smith (Main ID) <john.smith@email.com>

You want to observe the key with [C] capability and the sec label does not have a hash ("sec#"). If it does, you need to restore the key by loading the backup copy and use the following command to restore it:

$ gpg --import /path/to/you/key.asc

Export Primary Secret Key With All Sub-Keys

Once done, it's time to do the key export.

Determine Your Intention

Before you start, you should determine your intention of the exported key. There are only these few reasons to do such an export:

1. Export from transferring between PC to a New PC (e.g. Newly bought laptop)
2. Backing up your key.

Otherwise, refrain from exporting the key as it may hurt you.

Obtain Your Primary Key ID

We start off by obtaining your primary key ID. This is by using the following command and find your key:

$ gpg --list-secret-keys

Example:

$ gpg --list-secret-keys

...

---------------------------

sec   rsa4096 2020-01-10 [C]

      AC51A10307C10B2A4BB1C89AF5EF57A0FB4EF0EF

uid           [ultimate] "Shotgun" John, Smith (Main ID) <john.smith@email.com>

ssb   rsa4096 2020-01-10 [S] [expires: 2022-01-09]

ssb   rsa4096 2020-01-10 [E] [expires: 2022-01-09]

ssb   rsa4096 2020-01-10 [A] [expires: 2022-01-09]

ssb   ed25519 2020-01-10 [S] [expires: 2022-01-09]

ssb   ed25519 2020-01-10 [A] [expires: 2022-01-09]

ssb   cv25519 2020-01-10 [E] [expires: 2022-01-09]

You want the long string under the [C] key. In the example above, it is: AC51A10307C10B2A4BB1C89AF5EF57A0FB4EF0EF.

Export Key

Now use --export-secret-keys <ID> argument to create the secret key file. Ensure you redirect the output into a file.

GPG Binary Format

The common file extension would be .gpg. Here's the command:

$ gpg --export-secret-keys <ID> > /path/to/secret-key.gpg

You should get a binary file named secret-key.asc in /path/to.

TEXT Based Format

The common file extension would be .asc. If you want to export in a text-only format, append --armor argument in it. Here's the command:

$ gpg --armor --export-secret-keys <ID> > /path/to/secret-key.asc

You should get a text readable format like:

-----BEGIN PGP PRIVATE KEY BLOCK-----

... key data ...

-----END PGP PRIVATE KEY BLOCK-----

Text-only format is suitable for text-only storage, something like database.

Consume The Key File Immediately

As a good practice: DO NOT STORE the local key file. Consume it immediately like backing it up or whatever you intended to do **NOW**. Protect this key file at all cost throughout the consumption.

Delete The Key File

Once you're done with consumption, DELETE ALL local key copy file. Make sure you verify all the deletion thoroughly to avoid unnecessary identity disaster.

That's all about exporting secret keys with all sub-keys in GnuPG.