Document how to split a cert bundle into separate files

content/posts/2020-03-20-split-pem-bundle.md

+---
+title: "Splitting an X509 PEM-Encoded Certificate Bundle into Multiple Files"
+description: "Splitting a certificate bundle into separate files using `split` or `awk`."
+tags:
+- blogumentation
+- command-line
+- certificates
+license_code: Apache-2.0
+license_prose: CC-BY-NC-SA-4.0
+date: 2020-03-20T23:35:26+0000
+slug: "split-pem-bundle"
+---
+Today I was wanting to break out a large certificate bundle, containing many X509 PEM-encoded certs, into separate files. While I was thinking about scripting it myself, I realised _surely_ someone has done this before? It's a pretty standard thing for sysadmins to have done before, so resorted to searching online.
+
+Lo and behold, I found two great solutions via [_How to split a PEM file_ on Server Fault](https://serverfault.com/questions/391396/how-to-split-a-pem-file):
+
+Using the `split` command, which I've not tried before:
+
+```sh
+split -p "-----BEGIN CERTIFICATE-----" collection.pem individual-
+```
+
+Or using trusty `awk`:
+
+```sh
+awk '
+  split_after == 1 {n++;split_after=0}
+  /-----END CERTIFICATE-----/ {split_after=1}
+  {print > "cert" n ".pem"}' < $file
+```

permalinks.yml

 ---
 posts:
+- https://www.jvt.me/posts/2020/03/20/split-pem-bundle/
 - https://www.jvt.me/posts/2020/03/15/week-notes-11/
 - https://www.jvt.me/posts/2020/03/12/phpminds-march-slim/
 - https://www.jvt.me/posts/2020/03/08/week-notes-10/