A colleague asks for your GnuPG public key as text she can paste into an email. Which command produces exactly that on standard output?
LPIC-1 Exam 102-500, objective 110. Security medium
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How these questions are written — where each question comes from, what the verification ledger records, and what happens when one is found wrong.
The options
Correct gpg --armor --export you@example.com
Correct. --export writes the public key of the matching user ID, and --armor wraps the binary output in printable ASCII with BEGIN and END lines, which survives email intact.
Not correct gpg --armor --export-secret-keys you@example.com
Wrong, and a serious mistake. This exports the private key. Sending it to anyone destroys the security of the key pair, and there is no way to undo it other than revoking the key.
Not correct gpg --send-keys you@example.com
Wrong for this request, although it is a real operation. It uploads the public key to a keyserver rather than printing anything for you to paste.
Not correct gpg --import you@example.com
Wrong, and backwards. --import reads a key file and adds it to your keyring; it is what your colleague runs on the text you send her.
Why
--export and --import are the pair that move keys between keyrings, and --armor, short form -a, only changes the encoding from binary to ASCII. Note that the operation is asymmetric in risk: --export publishes something meant to be public, while --export-secret-keys is only ever for moving your own key to another machine you control. On the receiving side the key still has to be validated by fingerprint before it is trusted.
Where this comes from
- Cited
- manual page gpg(1)
Practise this
Reading one question is not practice. The trainer will draw a short set from objective 110 and space the ones you get wrong.
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