# Digitally sign PDF

## Install Okular PDF viewer

````{tabs}
```{code-tab} bash {{ arch_based }}
sudo pacman -S okular
```

```{code-tab} bash {{ debian_based }}
TODO
```
````

## Import certificate into Mozilla Firefox

You will need a `*.p12` file of your certificate (e.g. `sigen-ca g2 2483790412026.p12`).

1. Open Mozilla firefox and go to **Settings**.
2. Search for `certificates` and click **View Certificates**

![](./figs/firefox-cerificates.png)

3. Select **Your Certificates** and click **Import**.

![](figs/firefox-import-cert.png)

4. Now find your `*.p12` file and open it. Than enter your password (you should have gotten it when you claimed your certificate).

You have successfully imported your certificate into Firefox. 

## Add certificate in Okular

0. You should now have [certificate imported in Mozilla Firefox](#import-certificate-into-mozilla-firefox).
1. Create a directory to store your Okular certificates (e.g. `~/cert/okular`)

```bash
mkdir -p ~/cert/okular
```

1. Copy `key4.db` and `cert9.db` files from `~/.mozilla/firefox/XXXXXXXX.default-release/` (where`XXXXXXXX` is random string) to newly created directory.

```bash
cp ~/.mozilla/firefox/18yapjsu.default-release/key4.db ~/cert/okular/
cp ~/.mozilla/firefox/18yapjsu.default-release/cert9.db ~/cert/okular/
```

2. Open Okular expand **Settings** tab and click **Configure Backends**.

![](figs/okular-configure-backends.png)

3. Now select **PDF** in the sidebar, select **Custom** in **Certificate Database** group and click **Open File Dialog** button to select previously created directory (e.g. `~/cert/okular`).

![](figs/okular-certificate-database.png)

4. Click **OK** and close Okular. Now you are ready to digitally sign PDF dockuments (after you reopen Okular).