Tag: OpenDistro

ElasticSearch to OpenSearch: Local User Migration

One of the trickier bits of migrating from ElasticSearch to OpenSearch has been the local users — most of our users are authenticated via OAUTH, but programmatic access is done with local user accounts. Fortunately, you appear to be able to get the user password hash from the .opendistro_security API if you authenticate using an SSL cert.

This means the CN of the certificate being used must be registered in the elasticsearch.yml as an admin DN:

plugins.security.authcz.admin_dn:
  - 'CN=admin,O=LJRTest,ST=Ohio,C=US'
  - 'CN=ljradmin,O=LJRTest,ST=Ohio,C=US'

Provided the certificate is an admin_dn, the account can be used to search the .opendistro_security index and return local user info — including hashes. Information within the document is base 64 encoded, so the value needs to be decoded before you’ve got legible user information. One the user record has been obtained, the information can be used to POST details to the OpenSearch API and create a matching user. 

import json
import requests
import base64
from requests.auth import HTTPBasicAuth

clientCrt = "./certs/ljr-mgr.pem"
clientKey = "./certs/ljr-mgr.key"
strOSAdminUser = 'something'
strOSAdminPass = 'something'

r = requests.get("https://elasticsearch.example.com:9200/.opendistro_security/_search?pretty", verify=False, cert=(clientCrt, clientKey))
if r.status_code == 200:
        dictResult = r.json()

        for item in dictResult.get('hits').get('hits'):
                if item.get('_id') == "internalusers":
                        strInternalUsersXML = item.get('_source').get('internalusers')
                        strUserJSON = base64.b64decode(strInternalUsersXML).decode("utf-8")
                        dictUserInfo = json.loads(strUserJSON)
                        for tupleUserRecord in dictUserInfo.items():
                                strUserName = tupleUserRecord[0]
                                dictUserRecord = tupleUserRecord[1]
                                if dictUserRecord.get('reserved') == False:
                                        dictUserDetails = {
                                                "hash": dictUserRecord.get('hash'),
                                                "opendistro_security_roles": dictUserRecord.get('opendistro_security_roles'),
                                                "backend_roles": dictUserRecord.get('backend_roles'),
                                                "attributes": dictUserRecord.get('attributes')
                                                }

                                        if dictUserRecord.get('description') is not None:
                                                dictUserDetails["description"] = dictUserRecord.get('description')

                                        reqCreateUser = requests.put(f'https://opensearch.example.com:9200/_plugins/_security/api/internalusers/{strUserName}', json=dictUserDetails, auth = HTTPBasicAuth(strOSAdminUser, strOSAdminPass), verify=False)
                                        print(reqCreateUser.text)
else:
        print(r.status_code)

OpenID Authentication with OpenDistro

The following configuration changes needed to be made to enable federated authentication through OpenIDC using OpenDistro 1.8.0 withElasticSearch 7.7.0 — this presupposes that you have an application properly registered with an OIDC identity provider.

./kibana/config/kibana.yml

opendistro_security.auth.type: "openid"
opendistro_security.openid.connect_url: "https://login.example.com/.well-known/openid-configuration"
opendistro_security.openid.client_id: "REDACTED"
opendistro_security.openid.client_secret: "REDACTED"
opendistro_security.openid.scope: "openid"
opendistro_security.openid.header: "Authorization"
opendistro_security.openid.base_redirect_url: "https://opensearch.dev.example.com"

And then on the ElasticSearch node, update ./elasticsearch/config/elasticsearch.yml

opendistro_security.ssl.transport.truststore_filepath: cacerts

And ./elasticsearch/plugins/opendistro_security/securityconfig/config.yml

      basic_internal_auth_domain:
        description: "Authenticate via HTTP Basic against internal users database"
        http_enabled: true
        transport_enabled: true
        order: 4
        http_authenticator:
          type: basic
          challenge: true
        authentication_backend:
          type: intern
      openid_auth_domain:
        http_enabled: true
        transport_enabled: true
        order: 1
        http_authenticator:
          type: openid
          challenge: false
          config:
            enable_ssl: true
            verify_hostnames: false
            openid_connect_url: https://login.example.com/.well-known/openid-configuration
        authentication_backend:
          type: noop

Use securityadmin.sh to update — it helps if you update ./elasticsearch/plugins/opendistro_security/securityconfig/roles_mapping.yml

all_access:
  reserved: false
  backend_roles:
  - "admin"
  users:
  - "lisa"
  description: "Maps admin to all_access"

My experience is that the ElasticSearch API will allow authentication for local users. Kibana, however, does not — if you want to allow local users to log into Kibana, you’d either need a different Kibana instance (permanently allow local users to access Kibana) or update the kibana.yml to exclude the federated logon stuff & restart the service (temporary workaround when the identity provider has an issue).

The biggest challenge that I encountered is that there is, evidently, a bug in OpenDistro 1.13.1 that makes OIDC authentication non-functional. Downgrading to OpenDistro 1.13.0 worked, 1.8.0 (the version matched with our ElasticSearch 7.7.0 iteration) worked. And, reportedly, the newest 1.13.3 works as well.