adding role-based security and data masking to mysql through a hexatier proxy

©2002-2016 Teladoc, Inc. All rights reserved.

Adding Role-Based Security and Data Masking to MySQL through a Hexatier Proxy

10/28/2016


Introductions

Scott Uhrick• 22 Years an Oracle DBA in Health Care• 2 Years a MySQL DBA with Teladoc

Teladoc• First and largest telehealth platform in the United States• Provides 24/7 access to Board-certified medical care• 15 million members• 1.6+ million visits since inception


“A system should be as complex as it needs to be and no more than that” – Albert Einstein (very loosely paraphrased)

The Goal – Reduce Complexity in Security Administration

• The lack of role-based security in current versions of MySQL forces privileges to be managed at the level of the individual user.

• Managing privileges at this level makes it difficult to keep privileges consistent among users with identical job functions.

• Workarounds usually consist of standard “grant privilege” scripts which act as a creation template for standardized user-types.

• Such solutions can keep users consistent upon creation but does not affect;• Changing role requirements• Auditing (who has this role?)• Multiple roles per person • Human error

©2002-2016 Teladoc, Inc. All rights reserved.4

Hexatier Functionality

Hexatier provides database security at several different levels;

• Role-Based Data Access• Segregation of duties• Simplified administration

• Data Masking• Data masked in query result sets returned through Hexatier proxy• Same roles controlling data access can be used in data masking

• ie, not one-size-fits-all as with in-database encryption

• Data Discovery• Can scan tables to discover sensitive data

• Data Activity Monitoring• Logging can be set for individual Hexatier rules & policies, allowing

auditing to be as broad or narrow as desired.

• SQL Injection Attack Prevention


Hexatier Functionality in Use at Teladoc

Hexatier provides database security at several different levels;

• Role-Based Data Access• Segregation of duties• Simplified administration

• Data Masking• Data masked in query result sets returned through Hexatier proxy• Same roles controlling data access can be used in data masking

• ie, not one-size-fits-all as with in-database encryption

• Data Discovery• Can scan tables to discover sensitive data

• Data Activity Monitoring• Logging can be set for individual Hexatier rules & policies, allowing

auditing to be as broad or narrow as desired.

• SQL Injection Attack Prevention


Hexatier Architecture

• Hexatier is a network proxy process running on a Linux server, designed to receive and forward MySQL database connections

• Applications and MySQL clients see the proxy as a MySQL database. Hexatier receives the connections, applies rules and passes approved connections and queries on to the database


Hexatier Architecture

AppServers

Desktops

HexatierProxy

(10.240.20.100)

MySQLDatabase

AppServers

Desktops

HexatierProxy

(10.240.20.100)

MySQLDatabase

X

Note – As MySQL database accounts can be configured to include a host address, the architecture can be designed to ensure the proxy cannot be bypassed. All traffic will be subject to Hexatier authority.


Hexatier Dashboard

Opening screen displays • # of sessions• Recent violations• System Performance• Top users, rules and ip addresses


Table Access Control

• Hexatier allows users to be assigned to groups, and those groups to be assigned privileges.

• Privileges are managed via a series of rules, applied in a top-down manner to each data request.

• Hexatier’s use of rules and user-groups allows a form of role-based security to operate, greatly simplifying security management.


Table Access Control – Users on MySQL

Corresponding Users on Database:

• Users are created on the database with full privileges, relying on Hexatier to apply security.• This is secure as access is allowed ONLY through Hexatier proxy’s IP address (10.240.20.100)


Table Access Control – Users on Hexatier

Users (inherited from database) :

Users Groups (can contain users or other user groups) :


Table Access Control - Policies

• Ordering of rules is important, most restrictive at the bottom to catch “none of the above” and block all access. People with no rules assigned have no access.

• Grantee’s can be individual users or pre-defined groups of users ( roles ! )

Policies define table access rules


Table Access Control – Policy Contents

Contents of a Policy :

Users affected by policy

Restrictions can be database, table or column-based

Allowed privileges

Log violations?


Table Access Control - Example using “nyug1”

User “nyug1” defined on database Usergroup “dw_NYUG_members” created, user “nyug1” added to group

Usergroup “dw_demo_hexatier_ro” created, user “dw_NYUG_members” added to group Note – Up to this point Hexatier

is authorizing no privileges, user “nyug1” has no privs on the database. Usergroups are just logical constructions.


Table Access Control – Policy Example

Goal – set up policy allowing select on database “demo_hexatier”

Who

What

Privs


Additional Policy Options for Table-Based Security

16

Apply only to defined ip addresses

Apply only during defined periods

Apply only to defined applications


Table Access ControlExample using nyug1, effect of policy ;

1) Can see data in database “demo_hexatier”

2) No rows returned when querying database “DW“

3) Unable to update data in database “demo_hexatier”


What We’ve Just Done

18

Created user

nyug1

Created logical group of users

dw_NYUG_members

Created group to relate policies to user-groups

dw_demo_hexatier_ro

Created policy to define rules

dw_demo_hexatier_ro

Database

demo_hexatier

Users can be easily moved between user-groups

User-groups can be moved between policies

= Role-Based Security


Table Access Control – New Role for DMLCreate new user group to hold users allowed DML

Create new policy allowing DML, assign above user group to it


What We’ve Just Done

20

dw_NYUG_members dw_demo_hexatier_ro dw_demo_hexatier_ro demo_hexatier

dw_WashDC_members

Moving users between groups, groups between rules

dw_demo_hexatier_rw dw_demo_hexatier_rw


Additional Policy Options for Query-Based Security

21

Proxy can be set to record queries run against a database for a set period(in the case below, one week). Results in a “Query Group”.

Resulting Query Group Policy can be used to limit queries to those in the group or to simply notify when queries outside the group are run.


Data Masking

The eternal quest for protecting production data on non-production systems.

Options;

• Don’t have production data on non-production systems (produce and maintain a set of test data which reflects all possible data gotchas).

• Who maintains and how to ensure all necessary test cases are included?

• Develop on non-production data, QA on copy of production.• Reduces the exposure of production data to a subset of staff, the minimum

necessary to ensure quality releases.• Increased development time due to increased iterations between

development & QA.

• Encrypt or remove sensitive data from development copy of production.• One-size-fits-all, everyone has same level of obfuscation.• Encryption of indexed columns invalidates range scans.• Removal of data can invalidate foreign keys.


Data Masking through Hexatier

• Proxy holds rules describing which tables and columns should have data masked before being returned to client.

• Rules can be configured and granted dynamically.

• Different rules can apply to different users & user-groups.

• Data remains in the clear within database.

Not a perfect solution.

• As return set is masked, processes or analysis dependent on that result set are incorrect.


Data MaskingRule below instructs proxy to mask “first_nm”, “last_nm”, “user_nm” and “ssn” from role “dw_NYU_members;

If the data-types of the columns being masked by the policy are the same, there is great flexibility in how they are masked.


Effect of Data Masking on “nyug1”

Designated columns masked for “nyug1”

Masked tables remain join-able


Activity Auditing

• Each table access control rule can be set to write audit records each time it is invoked.

• Each data masking rule can be set to write audit records each time it is invoked.

• As each security installation will contain a rule to deny access to any query not matching a granting rule, auditing this rule records all attempts to access prohibited data.


Activity Auditing

Audit Record of a Policy Violation :


Performance Benchmarking

Industry-standard TPCC benchmarks were run against the Hexatier POC deployment with the following feature combinations enabled;

1. Baseline (proxy bypassed)2. Hexatier controling table access3. Hexatier access control and PHI masking4. Hexatier access control, PHI masking & full

transaction logging


Performance Benchmarking

System Details• Database

– AWS RDS MySQL, m3xlarge (4 CPU, 15GB ram, prov io ssd)

• Proxy Server– AWS EC2 Centos, m4large (2 CPU, 8GB ram, prov io ssd)

# Virtual Users

Transactions Per Minute

10 20 30 40 50 60 70 80 90 1000

100000

200000

300000

400000

500000

600000

700000

800000

900000

1000000

Baseline, Proxy BypassedProxy, Table Access Control, No MaskingProxy, Table Access Control, PHI MaskingProxy, Table Access Control, PHI Masking, all transactions logged

Note : Teladoc’s production database db1a.us1 averages approx. 35,000 TpM during business hours


Limitations and Implementation Suggestions

30

Hexatier as currently supplied has a few limitations to be aware of;

• Policies cannot cross schemas.• Cannot join “billing.table1” to “product.table2”

• Have had to maintain a few non-Hexatier accounts for the applications requiring this.

• Lack of consistent masking• While data can be masked a variety of ways it cannot be consistently

and uniquely obfuscated.• Eg., “John Smith” can be masked to “XXX XXXXX” but not to a

value which remains uniquely and consistently encrypted across the database. (“Hdbr 4Thdr” each time it is displayed).

• Some functions lack comments fields or the ability to track who-has-what.• Use of naming conventions necessary to get around this.

adding role-based security and data masking to mysql through a hexatier proxy

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