---
title: "Common"
description: "Common configuration options and notations."
lead: "This section details common configuration elements within the Authelia configuration. This section is mainly used as a reference for other sections as necessary."
date: 2022-06-15T17:51:47+10:00
draft: false
images: []
menu:
  configuration:
    parent: "prologue"
weight: 100200
toc: true
aliases:
  - /c/common
---

## Duration Notation Format

We have implemented a string/integer based notation for configuration options that take a duration of time. This section
describes the implementation of this. You can use this implementation in various areas of configuration such as:

* session:
  * expiration
  * inactivity
  * remember_me_duration
* regulation:
  * ban_time
  * find_time
* ntp:
  * max_desync
* webauthn:
  * timeout

The way this format works is you can either configure an integer or a string in the specific configuration areas. If you
supply an integer, it is considered a representation of seconds. If you supply a string, it parses the string in blocks
of quantities and units (number followed by a unit letter).  For example `5h` indicates a quantity of 5 units of `h`.

While you can use multiple of these blocks in combination, ee suggest keeping it simple and use a single value.

### Unit Legend

|  Unit   | Associated Letter |
|:-------:|:-----------------:|
|  Years  |         y         |
| Months  |         M         |
|  Weeks  |         w         |
|  Days   |         d         |
|  Hours  |         h         |
| Minutes |         m         |
| Seconds |         s         |

### Examples

|     Desired Value     |        Configuration Examples         |
|:---------------------:|:-------------------------------------:|
| 1 hour and 30 minutes | `90m` or `1h30m` or `5400` or `5400s` |
|         1 day         | `1d` or `24h` or `86400` or `86400s`  |
|       10 hours        | `10h` or `600m` or `9h60m` or `36000` |

## Address

The address type is a string that takes the following format:

```text
[<scheme>://]<ip>[:<port>]
```

The square brackets indicate optional sections, and the angled brackets indicate required sections. The following
sections elaborate on this. Sections may only be optional for the purposes of parsing, there may be a configuration
requirement that one of these is provided.

### scheme

The entire scheme is optional, but if the scheme host delimiter `://` is in the string, the scheme must be present. The
scheme must be one of `tcp://`, or `udp://`. The default scheme is `tcp://`.

### ip

The IP is required. If specifying an IPv6 it should be wrapped in square brackets. For example for the IPv6 address
`::1` with the `tcp://` scheme and port `80`: `tcp://[::1]:80`.

### port

The entire port is optional, but if the host port delimiter `:` exists it must also include a numeric port.

## Regular Expressions

We have several sections of configuration that utilize regular expressions. It's recommended to validate your regex
manually either via tools like [Regex 101](https://regex101.com/) (ensure you pick the `Golang` option) or some other
means.

It's important when attempting to utilize a backslash that it's utilized correctly. The YAML parser is likely to parse
this as you trying to use YAML escape syntax instead of regex escape syntax. To avoid this use single quotes instead of
no quotes or double quotes.

Good Example:

```yaml
domain_regex: '^(admin|secure)\.example\.com$'
```

Bad Example:

```yaml
domain_regex: "^(admin|secure)\.example\.com$"
```

## TLS Configuration

Various sections of the configuration use a uniform configuration section called TLS. Notably LDAP and SMTP.
This section documents the usage.

### server_name

{{< confkey type="string" required="no" >}}

The key `server_name` overrides the name checked against the certificate in the verification process. Useful if you
require an IP address for the host of the backend service but want to verify a specific certificate server name.

### skip_verify

{{< confkey type="boolean" default="false" required="no" >}}

The key `skip_verify` completely negates validating the certificate of the backend service. This is not recommended,
instead you should tweak the `server_name` option, and the global option
[certificates directory](../miscellaneous/introduction.md#certificates_directory).

### minimum_version

{{< confkey type="string" default="TLS1.2" required="no" >}}

The key `minimum_version` controls the minimum TLS version Authelia will use when opening TLS connections.
The possible values are `TLS1.3`, `TLS1.2`, `TLS1.1`, `TLS1.0`. Anything other than `TLS1.3` or `TLS1.2`
are very old and deprecated. You should avoid using these and upgrade your backend service instead of decreasing
this value.