# 1.2.22. Authentication

Interfaces for obtaining session and authorization data.

Note

We also strongly recommend you set up SSL to improve all authentication methods’ security.

## 1.2.22.1. Basic Authentication

Basic authentication (RFC 2617) is a quick and simple way to authenticate with CouchDB. The main drawback is the need to send user credentials with each request which may be insecure and could hurt operation performance (since CouchDB must compute the password hash with every request):

Request:

    GET / HTTP/1.1
    Accept: application/json
    Authorization: Basic cm9vdDpyZWxheA==
    Host: localhost:5984

Response:

    HTTP/1.1 200 OK
    Cache-Control: must-revalidate
    Content-Length: 177
    Content-Type: application/json
    Date: Mon, 03 Dec 2012 00:44:47 GMT
    Server: CouchDB (Erlang/OTP)

    {
        "couchdb":"Welcome",
        "uuid":"0a959b9b8227188afc2ac26ccdf345a6",
        "version":"1.3.0",
        "vendor": {
            "version":"1.3.0",
            "name":"The Apache Software Foundation"
        }
    }

## 1.2.22.2. Cookie Authentication

For cookie authentication (RFC 2109) CouchDB generates a token that the client can use for the next few requests to CouchDB. Tokens are valid until a timeout. When CouchDB sees a valid token in a subsequent request, it will authenticate the user by this token without requesting the password again. By default, cookies are valid for 10 minutes, but it’s `adjustable`. Also it’s possible to make cookies `persistent`.

To obtain the first token and thus authenticate a user for the first time, the `username` and `password` must be sent to the _session API.

### 1.2.22.2.1. `/_session`

`POST` `/_session`

  Initiates new session for specified user credentials by providing Cookie value.

  Request Headers:

  - Content-Type –
    - application/x-www-form-urlencoded
    - application/json

  Query Parameters:

  - next (string) – Enforces redirect after successful login to the specified location. This location is relative from server root. Optional.

  Form Parameters:

  - name – User name
  - password – Password

  Response Headers:

  - Set-Cookie – Authorization token

  Response JSON Object:

  - ok (boolean) – Operation status
  - name (string) – Username
  - roles (array) – List of user roles

  Status Codes:

  - 200 OK – Successfully authenticated
  - 302 Found – Redirect after successful authentication
  - 401 Unauthorized – Username or password wasn’t recognized

  Request:

      POST /_session HTTP/1.1
      Accept: application/json
      Content-Length: 24
      Content-Type: application/x-www-form-urlencoded
      Host: localhost:5984

      name=root&password=relax

  It’s also possible to send data as JSON:

      POST /_session HTTP/1.1
      Accept: application/json
      Content-Length: 37
      Content-Type: application/json
      Host: localhost:5984

      {
          "name": "root",
          "password": "relax"
      }

  Response:

      HTTP/1.1 200 OK
      Cache-Control: must-revalidate
      Content-Length: 43
      Content-Type: application/json
      Date: Mon, 03 Dec 2012 01:23:14 GMT
      Server: CouchDB (Erlang/OTP)
      Set-Cookie: AuthSession=cm9vdDo1MEJCRkYwMjq0LO0ylOIwShrgt8y-UkhI-c6BGw; Version=1; Path=/; HttpOnly

      {"ok":true,"name":"root","roles":["_admin"]}

  If `next` query parameter was provided the response will trigger redirection to the specified location in case of successful authentication:

  Request:

      POST /_session?next=/blog/_design/sofa/_rewrite/recent-posts HTTP/1.1
      Accept: application/json
      Content-Type: application/x-www-form-urlencoded
      Host: localhost:5984

      name=root&password=relax

  Response:

      HTTP/1.1 302 Moved Temporarily
      Cache-Control: must-revalidate
      Content-Length: 43
      Content-Type: application/json
      Date: Mon, 03 Dec 2012 01:32:46 GMT
      Location: http://localhost:5984/blog/_design/sofa/_rewrite/recent-posts
      Server: CouchDB (Erlang/OTP)
      Set-Cookie: AuthSession=cm9vdDo1MEJDMDEzRTp7Vu5GKCkTxTVxwXbpXsBARQWnhQ; Version=1; Path=/; HttpOnly

      {"ok":true,"name":null,"roles":["_admin"]}

`GET` `/_session`

  Returns information about the authenticated user, including a User Context Object, the authentication method and database that were used, and a list of configured authentication handlers on the server.

  Query Parameters:

  - basic (boolean) – Accept Basic Auth by requesting this resource. Optional.

  Response JSON Object:

  - ok (boolean) – Operation status
  - userCtx (object) – User context for the current user
  - info (object) – Server authentication configuration

  Status Codes:

  - 200 OK – Successfully authenticated.
  - 401 Unauthorized – Username or password wasn’t recognized.

  Request:

      GET /_session HTTP/1.1
      Host: localhost:5984
      Accept: application/json
      Cookie: AuthSession=cm9vdDo1MEJDMDQxRDpqb-Ta9QfP9hpdPjHLxNTKg_Hf9w

  Response:

      HTTP/1.1 200 OK
      Cache-Control: must-revalidate
      Content-Length: 175
      Content-Type: application/json
      Date: Fri, 09 Aug 2013 20:27:45 GMT
      Server: CouchDB (Erlang/OTP)
      Set-Cookie: AuthSession=cm9vdDo1MjA1NTBDMTqmX2qKt1KDR--GUC80DQ6-Ew_XIw; Version=1; Path=/; HttpOnly

      {
          "info": {
              "authenticated": "cookie",
              "authentication_db": "_users",
              "authentication_handlers": [
                  "cookie",
                  "default"
              ]
          },
          "ok": true,
          "userCtx": {
              "name": "root",
              "roles": [
                  "_admin"
              ]
          }
      }

`DELETE` `/_session`

  Closes user’s session by instructing the browser to clear the cookie. This does not invalidate the session from the server’s perspective, as there is no way to do this because CouchDB cookies are stateless. This means calling this endpoint is purely optional from a client perspective, and it does not protect against theft of a session cookie.

  Status Codes:

  - 200 OK – Successfully close session.

  Request:

      DELETE /_session HTTP/1.1
      Accept: application/json
      Cookie: AuthSession=cm9vdDo1MjA1NEVGMDo1QXNQkqC_0Qmgrk8Fw61_AzDeXw
      Host: localhost:5984

  Response:

      HTTP/1.1 200 OK
      Cache-Control: must-revalidate
      Content-Length: 12
      Content-Type: application/json
      Date: Fri, 09 Aug 2013 20:30:12 GMT
      Server: CouchDB (Erlang/OTP)
      Set-Cookie: AuthSession=; Version=1; Path=/; HttpOnly

      {
          "ok": true
      }

## 1.2.22.3. Proxy Authentication

Note

To use this authentication method make sure that the `{chttpd_auth, proxy_authentication_handler}` value is added to the list of the active `chttpd/authentication_handlers`:

    [chttpd]
    authentication_handlers = {chttpd_auth, cookie_authentication_handler}, {chttpd_auth, proxy_authentication_handler}, {chttpd_auth, default_authentication_handler}

Proxy authentication is very useful in case your application already uses some external authentication service and you don’t want to duplicate users and their roles in CouchDB.

This authentication method allows creation of a User Context Object for remotely authenticated user. By default, the client just needs to pass specific headers to CouchDB with related requests:

- `X-Auth-CouchDB-UserName`: username;
- `X-Auth-CouchDB-Roles`: comma-separated (`,`) list of user roles;
- `X-Auth-CouchDB-Token`: authentication token. When `proxy_use_secret` is set (which is strongly recommended!), this header provides an HMAC of the username to authenticate and the secret token to prevent requests from untrusted sources. (Use the SHA1 of the username and sign with the secret)

Creating the token (example with openssl):

    echo -n "foo" | openssl dgst -sha1 -hmac "the_secret"
    # (stdin)= 22047ebd7c4ec67dfbcbad7213a693249dbfbf86

Request:

    GET /_session HTTP/1.1
    Host: localhost:5984
    Accept: application/json
    Content-Type: application/json; charset=utf-8
    X-Auth-CouchDB-Roles: users,blogger
    X-Auth-CouchDB-UserName: foo
    X-Auth-CouchDB-Token: 22047ebd7c4ec67dfbcbad7213a693249dbfbf86

Response:

    HTTP/1.1 200 OK
    Cache-Control: must-revalidate
    Content-Length: 190
    Content-Type: application/json
    Date: Fri, 14 Jun 2013 10:16:03 GMT
    Server: CouchDB (Erlang/OTP)

    {
        "info": {
            "authenticated": "proxy",
            "authentication_db": "_users",
            "authentication_handlers": [
                "cookie",
                "proxy",
                "default"
            ]
        },
        "ok": true,
        "userCtx": {
            "name": "foo",
            "roles": [
                "users",
                "blogger"
            ]
        }
    }

Note that you don’t need to request session to be authenticated by this method if all required HTTP headers are provided.

## 1.2.22.4. JWT Authentication

Note

To use this authentication method, make sure that the `{chttpd_auth, jwt_authentication_handler}` value is added to the list of the active `chttpd/authentication_handlers`:

    [chttpd]
    authentication_handlers = {chttpd_auth, cookie_authentication_handler}, {chttpd_auth, jwt_authentication_handler}, {chttpd_auth, default_authentication_handler}

`JWT authentication` enables CouchDB to use externally-generated JWT tokens instead of defining users or roles in the `_users` database.

The JWT authentication handler requires that all JWT tokens are signed by a key that CouchDB has been configured to trust (there is no support for JWT’s “NONE” algorithm).

Additionally, CouchDB can be configured to reject JWT tokens that are missing a configurable set of claims (e.g, a CouchDB administrator could insist on the `exp` claim).

Only claims listed in required checks are validated. Additional claims will be ignored.

Two sections of config exist to configure JWT authentication;

The `required_claims` config setting is a comma-separated list of additional mandatory JWT claims that must be present in any presented JWT token. A :code 400:Bad Request is sent if any are missing.

The `alg` claim is mandatory as it used to lookup the correct key for verifying the signature.

The `sub` claim is mandatory and is used as the CouchDB user’s name if the JWT token is valid.

A private claim called `_couchdb.roles` is optional. If presented, as a JSON array of strings, it is used as the CouchDB user’s roles list as long as the JWT token is valid.

    ; [jwt_keys]
    ; Configure at least one key here if using the JWT auth handler.
    ; If your JWT tokens do not include a "kid" attribute, use "_default"
    ; as the config key, otherwise use the kid as the config key.
    ; Examples
    ; hmac:_default = aGVsbG8=
    ; hmac:foo = aGVsbG8=
    ; The config values can represent symmetric and asymmetrics keys.
    ; For symmetrics keys, the value is base64 encoded;
    ; hmac:_default = aGVsbG8= # base64-encoded form of "hello"
    ; For asymmetric keys, the value is the PEM encoding of the public
    ; key with newlines replaced with the escape sequence \n.
    ; rsa:foo = -----BEGIN PUBLIC KEY-----\nMIIBIjAN...IDAQAB\n-----END PUBLIC KEY-----\n
    ; ec:bar = -----BEGIN PUBLIC KEY-----\nMHYwEAYHK...AzztRs\n-----END PUBLIC KEY-----\n

The `jwt_key` section lists all the keys that this CouchDB server trusts. You should ensure that all nodes of your cluster have the same list.

JWT tokens that do not include a `kid` claim will be validated against the `$alg:_default` key.

It is mandatory to specify the algorithm associated with every key for security reasons (notably presenting a HMAC-signed token using an RSA or EC public key that the server trusts: https://auth0.com/blog/critical-vulnerabilities-in-json-web-token-libraries/).

Request:

    GET /_session HTTP/1.1
    Host: localhost:5984
    Accept: application/json
    Content-Type: application/json; charset=utf-8
    Authorization: Bearer <JWT token>

Response:

    HTTP/1.1 200 OK
    Cache-Control: must-revalidate
    Content-Length: 188
    Content-Type: application/json
    Date: Sun, 19 Apr 2020 08:29:15 GMT
    Server: CouchDB (Erlang/OTP)

    {
        "info": {
            "authenticated": "jwt",
            "authentication_db": "_users",
            "authentication_handlers": [
                "cookie",
                "proxy",
                "default"
            ]
        },
        "ok": true,
        "userCtx": {
            "name": "foo",
            "roles": [
                "users",
                "blogger"
            ]
        }
    }

Note that you don’t need to request session to be authenticated by this method if the required HTTP header is provided.