The TLS protocol versions accepted and the Cipher suites selected are controlled by the specification list set in the "SSL Ciphers" field on the HTTP App Server Configuration panel:


 

The specification list format follows the OpenSSL format described in the OpenSSL Cipher suite documentation. It comprises one or more colon ":" separated cypher strings that control which cypher suites are enabled or disabled.

The default specification used by MarkLogic enables ALL cyphers except those considered to have LOW encryption and arranges them in order of @STRENGTH.

ALL:!LOW:@STRENGTH

While sufficient for many needs, the default settings still allow for cypher negotiations that are no longer considered secure or weak signature algorithms, such as MD2 and MD5. The following cypher specification string enhances security by only permitting high-strength cyphers and disabling weak or vulnerable cyphers.

EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS:!EDH:!RC4

For sites requiring even higher levels of security, restricting the cyphers available to a specific list can provide a more advanced level of control of the cyphers used. For example, the following cypher suite list restricts algorithms to those used by TLSv1.2 only. It would be best if you, therefore, disabled all other TLS protocols as described below before using this setting in MarkLogic.

DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256

The following string restricts the algorithms available by only permitting TLSv1.2 cyphers using a 256-bit key. While this increases security even further, it risks being incompatible with many browsers and applications and should only be used after thorough testing.

DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384

At this stage, while the MarkLogic HTTP Application Server is now using more robust security, it will still permit a client to connect using TLSv1.0 or TLsv1.1. To comply with PCI DSS 3.2 and other recommended security standards, compliant sites must stop using TLSv1.0 before 30 June 2018, while NIST SP 800-52 requires that sites only use TLSv1.1, with a recommendation to use TLSv1.2 where possible.

Note: Since this article was written, the MarkLogic server has added an administrator function to disable individual SSL and TLS protocol versions. If you are still running MarkLogic version 8.0-5 or earlier, you can continue to use the solution outlined below. Otherwise, users of MarkLogic 9 or later should use the new AppServer Set SSL Disabled Protocols function to control which SSL and TLS protocol versions are available. When running against the Security Database, the XQuery code will disable all but TLSv1.2 on MarkLogic 9 or later.
 

xquery version "1.0-ml";

import module namespace admin = "http://marklogic.com/xdmp/admin""
      at "/MarkLogic/admin.xqy";

let $config := admin:get-configuration()
let $appServer := admin:appserver-get-id($config,
    admin:group-get-id($config, "Default"),"ssl-project-appserver")
return
   admin:save-configuration(admin:appserver-set-ssl-disabled-protocols($config, $appServer, ("SSLv3","TLSv1","TLSv1_1")))

xquery version "1.0-ml";

import module namespace admin = "http://marklogic.com/xdmp/admin"" at "/MarkLogic/admin.xqy";
let $config := admin:get-configuration()
let $appServer := admin:appserver-get-id($config,admin:group-get-id($config, "Default"), "mh-photos-test")
return
  admin:appserver-get-ssl-disabled-protocols($config, $appServer)

Output

SSLv3
TLSv1
TLSv1_1

Warning: Disabling all but TLSv1.2 and restricting available ciphers may break connectivity with applications and browsers configured to use SSLv3, TLSv1.0 or TLSv1.1. MarkLogic recommends that you test thoroughly in a lower QA environment before disabling any algorithms and protocols in a production environment.

HTTP Strict-Transport-Security

 The HTTP Strict-Transport-Security response header (often abbreviated as HSTS) informs browsers that the site should only be accessed using HTTPS and that any future attempts to access it using HTTP should automatically be converted to HTTPS.

Set the "enable hsts header" to True to enable HSTS for the AppServer when your security requirements dictate it. 

 

TLSv1.2 and browser support (MarkLogic 8 only)

For TLSv1.2, older browsers should be upgraded to current versions.

These changes may require users accessing your application to upgrade to older browsers such as Firefox < 27.0 or Internet Explorer < 11.0, as these versions do not support TLSv1.2 by default.

The MarkLogic App Server utilizes OpenSSL, which does not explicitly support enabling or disabling a specific TLS protocol version. However, you effectively get the same outcome by disabling all cypher suites associated with a particular version.

SSLv3, TLSv1.0 & TLSv1.1 share the same common ciphers, so adding "!SSLv3" and "!TLSv1.0 "to the cipher specification will cause all client connection attempts using any of these protocols to fail, including "TLSv1.1".

EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!SRP:!DSS:!EDH:!RC4:!SSLv3:!TLSv1.0

Testing using the OpenSSL s_client utility shows that attempts to connect using TLSv1.0 fail with SSL alert 40, indicating no common cypher was available.

openssl s_client -connect 192.168.99.100:8010 -debug -tls1
CONNECTED(00000003)
..
140735283961936:error:14094410:SSL routines:ssl3_read_bytes:sslv3 alert handshake failure:s3_pkt.c:1472:SSL alert number 40
140735283961936:error:1409E0E5:SSL routines:ssl3_write_bytes:ssl handshake failure:s3_pkt.c:656:

While connecting using TLSv1.2 is successful.

openssl s_client -connect 192.168.99.100:8010 -debug -tls1_2
CONNECTED(00000003)
...
---
New, TLSv1/SSLv3, Cipher is AES256-GCM-SHA384
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol : TLSv1.2
Cipher : AES256-GCM-SHA384

 

Further reading

• https://en.wikipedia.org/wiki/Transport_Layer_Security
• https://en.wikipedia.org/wiki/POODLE
• https://en.wikipedia.org/wiki/FREAK
• https://en.wikipedia.org/wiki/Logjam_(computer_security)
• RedHat: SLOTH: TLS 1.2 vulnerability (CVE-2015-7575)

On MarkLogic Security Certification

• MarkLogic: Certified Security Datasheet
• http://www.marklogic.com/press-releases/common-criteria/
• http://www.marklogic.com/blog/nothing-common-about-the-common-criteria-security-certification/
• Commons Criteria Documentation for MarkLogic Server 9 (PDF: November 2017)