Update openssl.md

openssl.md

@@ -9,3 +9,17 @@ openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt
 ```
 
 - Use `server.crt` and `server.key`
+
+### Encypt/Decrypt file
+
+```
+# Encrypt
+openssl aes-128-cbc -a -e -pass pass:test -in vars -out vars.enc
+# Puts encrypted data into vars.enc file
+
+# Decrypt
+openssl aes-128-cbc -a -d -pass pass:test -in vars.enc
+# Outputs decrypted data to STDOUT
+```
+
+NOTE: See `openssl passpharse arguments` for information on using the password on the commandline. It can be changed to a file or an environment variable.