Background:
- How to write an article
- GPG = "GNU Privacy Guard"
- GPG 1.4.10 Stateless Operations


Prerequisite:
- How to generate a GPG key




1) Place an article you have written into its own separate text file.

For this recipe, we'll assume that the file is named "article.txt".




2) Remove the last newline from the data in the article file.

Even if you didn't write one yourself, some text editors (e.g. vim) add one automatically.

Rationale: The article data should be completely enclosed in an "<article>" tag and an "</article>" end tag.




3) Create a temporary home directory for GPG to use.






4) Import the private key into the temporary directory.



Example:





5) Sign the article file, producing a detached signature file.

The signature will be made using the imported private key.






6) Delete the temporary directory.






7) Delete the GPG wrapper lines around the signature data.

Let's do a worked example.

Here is the content of an example signature file:




Delete these lines at the top:



And this one at the bottom:






8) Wrap the signature data in an "<author_signature>" tag.

Result:






9) Place the signature data at the end of the article file, and wrap the result with a "<signed_article>" tag.

Here is the simplest possible article:



After we add the signature data and the "<signed_article>" tag, it will look like this:






10) Result.

We have created a signature for the article, and added this signature to the data, producing a signed article file.

Note: A worked example with included output is available in the article GPG 1.4.10 Stateless Operations, in the section GPG 1.4.10 Stateless Operations With Example Output, in the part "7) Sign a file using a specific private key, producing a detached signature file".