authelia/docs/content/en/configuration/prologue/common.md

---
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: 2022-03-20T12:52:27+11:00
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` |

## 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 to use a direct IP address for the address of the backend service but want to verify a specific SNI.

### 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.