traefik/docs/content/https/tls.md

TLS

Transport Layer Security {: .subtitle }

Certificates Definition

Automated

See the Let's Encrypt page.

User defined

To add / remove TLS certificates, even when Traefik is already running, their definition can be added to the dynamic configuration, in the [[tls.certificates]] section:

[[tls.certificates]]
  certFile = "/path/to/domain.cert"
  keyFile = "/path/to/domain.key"

[[tls.certificates]]
  certFile = "/path/to/other-domain.cert"
  keyFile = "/path/to/other-domain.key"

!!! important "File Provider Only"

In the above example, we've used the [file provider](../providers/file.md) to handle these definitions.
In its current alpha version, it is the only available method to configure the certificates (as well as the options and the stores).

Certificates Stores

In Traefik, certificates are grouped together in certificates stores, which are defined as such:

[tls.stores]
  [tls.stores.default]

!!! important "Alpha restriction"

During the alpha version, any store definition other than the default one (named `default`) will be ignored,
and there is thefore only one globally available TLS store.

In the [[tls.certificates]] section, a list of stores can then be specified to indicate where the certificates should be stored:

[[tls.certificates]]
  stores = ["default"]
  certFile = "/path/to/domain.cert"
  keyFile = "/path/to/domain.key"

[[tls.certificates]]
  # Note that since no store is defined,
  # the certificate below will be stored in the `default` store.
  certFile = "/path/to/other-domain.cert"
  keyFile = "/path/to/other-domain.key"

!!! important "Alpha restriction"

During the alpha version, the `stores` list will actually be ignored and automatically set to `["default"]`.

Default Certificate

Traefik can use a default certificate for connections without a SNI, or without a matching domain. This default certificate should be defined in a TLS store:

[tls.stores]
  [tls.stores.default]
    [tls.stores.default.defaultCertificate]
      certFile = "path/to/cert.crt"
      keyFile  = "path/to/cert.key"

If no default certificate is provided, Traefik generates and uses a self-signed certificate.

TLS Options

The TLS options allow one to configure some parameters of the TLS connection.

Minimum TLS Version

[tls.options]

  [tls.options.default]
    minVersion = "VersionTLS12"

  [tls.options.mintls13]
    minVersion = "VersionTLS13"

Mutual Authentication

Traefik supports both optional and strict (which is the default) mutual authentication, though the ClientCA.files section. If present, connections from clients without a certificate will be rejected.

For clients with a certificate, the optional option governs the behaviour as follows:

• When optional = false, Traefik accepts connections only from clients presenting a certificate signed by a CA listed in ClientCA.files.
• When optional = true, Traefik authorizes connections from clients presenting a certificate signed by an unknown CA.

[tls.options]
  [tls.options.default]
    [tls.options.default.ClientCA]
      # in PEM format. each file can contain multiple CAs.
      files = ["tests/clientca1.crt", "tests/clientca2.crt"]
      optional = false

Cipher Suites

See cipherSuites for more information.

[tls.options]
  [tls.options.default]
    cipherSuites = [
      "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
      "TLS_RSA_WITH_AES_256_GCM_SHA384"
    ]

Strict SNI Checking

With strict SNI checking, Traefik won't allow connections from clients connections that do not specify a server_name extension.

[tls.options]
  [tls.options.default]
    sniStrict = true