Duo can be integrated with almost any device or system that supports using LDAP for authentication. In this type of configuration, users will receive an automatic push or phone callback during login. Users who need to use a passcode have the option to append it to their existing password when logging in.
Duo can be integrated with most devices and systems that support LDAP for authentication.
This configuration doesn't support inline self-service enrollment. You'll need to create your users in Duo ahead of time using one of our other enrollment methods, like directory sync or CSV import. Read the enrollment documentation to learn more.
This application communicates with Duo's service on TCP port 443. Firewall configurations that restrict outbound access to Duo's service with rules using destination IP addresses or IP address ranges aren't recommended, since these may change over time to maintain our service's high availability. If your organization requires IP-based rules, please review this Duo KB article.
To integrate Duo with your LDAP device, you will need to install a local proxy service on a machine within your network. Before proceeding, you should locate (or set up) a system on which you will install the Duo Authentication Proxy. The proxy supports Windows and Linux systems (in particular, we recommend Windows Server 2012 R2 or later, Red Hat Enterprise Linux 6 or later, CentOS 6 or later, or Debian 6 or later).
Then you'll need to:
The security of your Duo application is tied to the security of your secret key (skey). Secure it as you would any sensitive credential. Don't share it with unauthorized individuals or email it to anyone under any circumstances!
The Duo Authentication Proxy can be installed on a physical or virtual host. We recommend a system with at least 1 CPU, 200 MB disk space, and 4 GB RAM (although 1 GB RAM is usually sufficient).
Ensure that Perl and a compiler toolchain are installed. On most recent RPM-based distributions — like Fedora, RedHat Enterprise, and CentOS — you can install these by running (as root):
$ yum install gcc make libffi-devel perl zlib-develOn Debian-derived systems, install these dependencies by running (as root):
$ apt-get install build-essential libffi-dev perl zlib1g-devDownload the most recent Authentication Proxy for Unix from https://dl.duosecurity.com/duoauthproxy-latest-src.tgz. Depending on your download method, the actual filename may reflect the version e.g. duoauthproxy-5.1.0-src.tgz. View checksums for Duo downloads here.
Extract the Authentication Proxy files and build it as follows:
$ tar xzf duoauthproxy-latest-src.tgz
$ cd duoauthproxy-version-src
$ makeInstall the authentication proxy (as root):
$ cd duoauthproxy-build
$ ./installFollow the prompts to complete the installation. The installer creates a user to run the proxy service and a group to own the log directory and files. You can accept the default user and group names or enter your own.
The proxy listens for connections on ports 389 and 636 by default. Privileged ports below 1024 are reserved for the root user. Therefore, the proxy will not start if you choose any user account other than "root" to run under during installation.
If you ever need to uninstall the proxy, run /opt/duoauthproxy/uninstall.
After the installation completes, you will need to configure the proxy.
The Duo Authentication Proxy configuration file is named authproxy.cfg, and is located in the conf subdirectory of the proxy installation. With default installation paths, the proxy configuration file will be located at:
| Operating System | Authentication Proxy Version |
Path |
|---|---|---|
| Windows | v5.0.0 and later | C:\Program Files\Duo Security Authentication Proxy\conf\authproxy.cfg |
| Windows | v4.0.2 and earlier | C:\Program Files (x86)\Duo Security Authentication Proxy\conf\authproxy.cfg |
| Linux | All | /opt/duoauthproxy/conf/authproxy.cfg |
Note that as of v4.0.0, the default file access on Windows for the conf directory is restricted to the built-in Administrators group during installation.
The configuration file is formatted as a simple INI file. Section headings appear as:
[section]Individual properties beneath a section appear as:
name=valueThe Authentication Proxy may include an existing authproxy.cfg with some example content. For the purposes of these instructions, however, you should delete the existing content and start with a blank text file. We recommend using WordPad or another text editor instead of Notepad when editing the config file on Windows.
In this step, you'll set up the Proxy's primary authenticator — the system which will validate users' existing passwords. The primary authentication source for Duo LDAP must be another LDAP directory. In most cases, this means configuring the Proxy to communicate with Active Directory.
To use Active Directory/LDAP as your primary authenticator, add an [ad_client] section to the top of your config file. Add the following properties to the section:
Required
host
|
The hostname or IP address of your domain controller. |
service_account_username
|
The username of a domain account that has permission to bind to your directory and perform searches. We recommend creating a service account that has read-only access. |
service_account_password
|
The password corresponding to |
search_dn
|
The LDAP distinguished name (DN) of an Active Directory container or organizational unit (OU) containing all of the users you wish to permit to log in. For example: |
Optional
host_2
|
The hostname or IP address of a secondary/fallback domain controller. You can add additional domain controllers as |
security_group_dn
|
To further restrict access, specify the LDAP distinguished name (DN) of a security group that contains the users who should be able to log in as direct group members. Nested groups are not supported. Users who are not direct members of the specified group will not pass primary authentication. Example: Starting with Authentication Proxy v3.2.0, the |
For example:
[ad_client]
host=1.2.3.4
host_2=1.2.3.5
service_account_username=duoservice
service_account_password=password1
search_dn=DC=example,DC=com
security_group_dn=CN=DuoVPNUsers,OU=Groups,DC=example,DC=comFor advanced Active Directory configuration, see the full Authentication Proxy documentation.
Next, you need to set up the Authentication Proxy to handle LDAP authentication requests. Create an [ldap_server_auto] section and add the properties listed below. If you've already set up the Duo Authentication Proxy for a different LDAP application, append a number to the section header to make it unique, like [ldap_server_auto2].
Required
ikey
|
Your integration key. |
||
skey
|
Your secret key. |
||
api_host
|
Your API hostname (i.e. api-XXXXXXXX.duosecurity.com) |
||
client
|
The mechanism that the Authentication Proxy should use to perform primary authentication. This should correspond with a "client" section elsewhere in the config file.
This parameter is optional if you only have one "ad_client" section. If you have multiple, each "server" section should specify which "client" to use. |
Optional
failmode
|
Either "safe" or "secure":
|
||||
ssl_cert_path
|
Path to PEM-formatted SSL/TLS server certificate. Both |
||||
ssl_key_path
|
Path to PEM-formatted SSL/TLS private key. Both |
||||
exempt_primary_bind
|
If set to "true" (the default) then multi-factor authentication will not be performed for the first successful LDAP authentication in each connection. Use this if the device using the Authentication Proxy first connects as a service user and then authenticates the user who is logging in. |
||||
exempt_ou_1
|
Specify either the DN of a single user or an OU. Multi-factor authentication will not be required for these users. Set this option if the device using the Authentication Proxy first connects as a service user, disconnects, and then authenticates the user who is logging in with a separate LDAP connection. The exemptions should cover those service user(s). |
A completed config file, using Active Directory as the primary authenticator, should look something like:
[ad_client]
host=1.2.3.4
service_account_username=duoservice
service_account_password=password1
search_dn=cn=Users,dc=example,dc=com
[ldap_server_auto]
client=ad_client
ikey=DIXXXXXXXXXXXXXXXXXX
skey=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
api_host=api-XXXXXXXX.duosecurity.com
failmode=safe
ssl_key_path=ldap_server.key
ssl_cert_path=ldap_server.pemMake sure to save your configuration file when done.
See the AuthProxy Reference Guide for additional AuthProxy LDAP configuration options.
Open an Administrator command prompt and run:
net start DuoAuthProxyAlternatively, open the Windows Services console (services.msc), locate "Duo Security Authentication Proxy Service" in the list of services, and click the Start Service button.
Authentication Proxy v5.1.0 and later includes the authproxyctl executable, which shows the connectivity tool output when starting the service. The installer adds the Authentication Proxy C:\Program Files\Duo Security Authentication Proxy\bin to your system path automatically, so you should not need to specify the full path to authproxyctl to run it.
From an administrator command prompt run:
authproxyctl startIf the service starts successfully, Authentication Proxy service output is written to the authproxy.log file, which can be found in the log subdirectory.
If you see an error saying that the "service could not be started", open the Application Event Viewer and look for an Error from the source "DuoAuthProxy". The traceback may include a "ConfigError" that can help you find the source of the issue.
Stop and restart the Authentication Proxy service by either clicking the Restart Service button in the Windows Services console or issuing these commands from an Administrator command prompt:
net stop DuoAuthProxy & net start DuoAuthProxyTo stop and restart the Authentication Proxy using authproxyctl, from an administrator command prompt run:
authproxyctl restartOpen a root shell and run:
# /opt/duoauthproxy/bin/authproxyctl startTo ensure the proxy started successfully, run:
# /opt/duoauthproxy/bin/authproxyctl statusAuthentication Proxy service output is written to the authproxy.log file, which can be found in the log subdirectory.
To stop and restart the Authentication Proxy, open a root shell and run:
# /opt/duoauthproxy/bin/authproxyctl restartIf you modify your authproxy.cfg configuration after initial setup, you'll need to stop and restart the Duo Authentication Proxy service or process for your change to take effect.
Once the proxy is up and running, you need to configure your LDAP clients to use it for authentication.
In your clients' settings, set the LDAP server to the IP address or host name of your Duo authentication proxy. Set the LDAP server port to 636 to secure the connection with SSL.
The service user name and service password configured on the LDAP client(s) should be the same as it would be if you were configured to connect directly to the AD or LDAP server.
If your clients allow you to configure the LDAP timeout, set them to values such that the clients will not give up for at least 60 seconds. This is necessary if your users choose to use Duo's out-of-band factors (phone callback, push) to log in, as the authentication proxy will not be able to respond to a LDAP authentication request until the user responds to the authentication challenge. If your clients do not allow you to configure the LDAP timeout behavior, then your users may be unable to authenticate with Duo's out-of-band factors.
To test your setup, attempt to log in to your newly-configured system as a user enrolled in Duo with an authentication device.
When you enter your username and password, you will receive an automatic push or phone callback.
Alternatively you can add a comma (",") to the end of your password, followed by a Duo passcode. For example, given a username 'bob', with password 'password123' and a Duo passcode '123456', you would enter:
username: bob
password: password123,123456In addition, you may also enter the name of an out-of-band factor in lieu of a passcode. You may choose from the following factor names:
| push |
Perform Duo Push authentication You can use Duo Push if you've installed and activated Duo Mobile on your device. |
| phone | Perform phone callback authentication. |
| sms |
Send a new batch of SMS passcodes. Your authentication attempt will be denied. You can then authenticate with one of the newly-delivered passcodes. |
Returning to the previous example, if you wanted to use Duo Push (rather than a passcode) to authenticate, you would enter:
username: bob
password: password123,push
You can also specify a number after the factor name if you have more than one device enrolled (as the automatic push or phone call goes to the first capable device attached to a user). So you can enter phone2 or push2 if you have two phones enrolled and you want the authentication request to go to the second phone.
Need some help? Review troubleshooting tips for the Authentication Proxy and try the connectivity tool included with Duo Authentication Proxy 2.9.0 and later to discover and troubleshoot general connectivity issues.
Also take a look at our LDAP Knowledge Base articles or Community discussions. For further assistance, contact Support.
