CS317 File and Database Systemsmercury.pr.erau.edu/~siewerts/cs317/documents/Lectures/... · 2017....

November 13, 2017 Sam Siewert

CS317File and Database Systems

Lecture 12 – DBMS Security Considerations

http://dilbert.com/strips/comic/2009-02-21/

RemindersAssignment #4 Grading Now

Assignment #5, Physical DB Design – Reviewing TEAMS

Assignment #6, DBMS Project of Your Interest – POSTEDFINAL ORAL PRESENTATION– Design Schema for DBMS project in a small team

Logical design focusNormalizationPhysical is MySQL on PRClab

– Combine Network Applications with DBMS in C/C++, JDBC, or Python - http://www.mysql.com/products/connector/

– Add Stored Programs and Triggers– Add Views– Create Transactions where needed

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GENERAL PLATFORM SECURITY

Security Primer

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Key IssuesNIST (National Institute of Standards and Tech)– Department of Commerce– Data privacy and protection– FISMA (Federal Information Security and Modernization Act)– Detailed categorization of federal information and systems (threat,

risk, cost, benefit) - FIPS 199, FIPS 200, FIPS 800 v1, v2

How would YOU prioritize Data Security?1. Data Privacy (Disclosure to unauthorized user, system,

application)2. Misuse of Data (Fraud, Identity Theft)3. Fake Data (forged documents or credentials)4. Access Privilege Violations (Seeing Co-worker salaries)5. Data Corruption (Integrity, Veracity)6. Denial of Service (Can’t Access Data or Services due to Attack)7. Data Loss (Restore from backup? - RTO/RPO)

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Recent Data Security Disasters and Lessons to Learn

Equifax - facing potential judgment of corporate dissolution (corporate death penalty)Companies like this are “data stewards”, entrusted with personal financial data to provide services for pay - this is their job Why? 145.5 million personal records compromised (financial records used in credit scores)Mistakes exposed in Congressional Hearings (6 Fresh Horrors From the Equifax CEO's Congressional Hearing)1. Slow to act on knowledge of breach2. Software vulnerability patching process (points of failure, human

and automation) - one system had user=admin, pass=admin, Apache struts vulnerability ignored

3. Data storage of sensitive consumer information in plaintext4. Quarterly security reviews (infrequent for primary business)5. Not sure who is attacking them (or attacked)6. Breach notification separate system (domain)

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Authorization and Access ControlBy Session LoginBy File (permissions)By DirectoryHost to Network (Known host Ethernet address, WWID)By Execution Privilege Level (root or user) –“sudo”

Authorized Users, Computers, and Applications– Encrypted password, pass phrase, password hash (salt)

- “Randomness in Digital Cryptography: A Survey”– Avoid Dictionary and Birthday attacks

Download password files (to crack)Use dictionary derived guessesProbability of one password matching any other is higher than one matching a specificInformed guessing and testing

Require Authentication– Proving you are who you claim you are– Producing a pass phrase, an answer to a challenge

question– Key or smartcard– Providing biometric scan

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Marton, Kinga, Alin Suciu, and Iosif Ignat. "Randomness in digital cryptography: A survey." Romanian Journal of Information Science and Technology 13.3 (2010): 219-240.

10% of the Internet Is Encrypted with Lava Lamps

Attacks on SecurityEarly Famous Attacks– DES (Banking) Encryption for ATM machines– EFF Showed Weakness in DES (Cluster attack, then FPGA)– Scramble to patch with Triple DES (1996 timeframe)– NIST competition for AES (Advanced Encryption Standard)

Cryptanalysis– Capture Encrypted Data (“Man in the middle”)– Capture Encryption code, key, or mechanism– Capture Decryption code, key, or mechanism– Analyze Examples to Deduce the Substitution and Transposition

Cypher Code mappings– Inverse Function

Defense– Very Large Cryptographic Hashing Functions– 128-bit, 256-bit or larger random number generators– Frequent Key Updates

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Denial of ServiceRather than Gaining Unauthorized Access, Deny Other Authorized Users Access– Bug System with 1000’s or Millions of Invalid Requests Per

Second– Flood Network with Bad Protocol or Packets– Cause Routing Loops, Crash Services Remotely on Purpose

Reason for Maximum Login Attempts– Withdraw Prompt for Password to A Particular Network Client or

Terminal– Invalidate a Username

Reason for Network Authentication of Clients– Block All Traffic for a Specific IP or Ethernet Address– Secure Physical Network Switches and Gateway Machines

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MalwareSoftware Designed to Harm a Client or Exploit a Known Bug– Trojan Horse – Present Free Software, an E-mail Application, Plug-In, or

other Method to Deliver an Application with Bad IntentUser Agrees to Download without Authentication of Source or Verification of Code Data Digest (Unique Signature for Tested and Authentic Code)Beware of Free Software from Unknown Sources

– Virus – Application Code that Installs Itself on a Computer in Key Operating System and Shared Data Locations

Boot CodeCommonly Used File system CodeTransfer Malware via Shared Files, Networks, Disks (e.g. USB stick)

– Exploit – Find Buffer Overflow on Widely Used Operating System or Networking Service to Exploit

Buffer Overflow Provides Doorway to Modify CodePerfect Exploit in Private Lab, Release as Trojan Horse or Virus

– Rootkit – Gain Access and Install Monitoring Software or Create Second Administrator Prviliege Password and Account

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PhishingWrite A Program that Asks for a Password– Run this on a Public Computing System – Spoofing a Well-

known and Trusted Server– Collect Login Credentials from Users (Produce Error Messages)

Fake E-mail Requesting Credentials

Fake Service or Business Front

Impersonation of a Web Service (Re-direction of Traffic)

E-mail Indicating your Are Over E-mail Quota Limits, Credit has Been Frozen, Etc. Followed by Request for Credentials Sam Siewert 10

Newer Threats Continue to Emerge …Character Defamation– Impersonation of Web Presence– Defame a User - a.k.a. “Fake News”– Influence a Stock Price (“Pump & Dump”)– Confuse or Influence with specific purpose

Identity Theft – Creation of Accounts Using False Credentials– Outright theft (credit card fraud)– Less obvious - Sign up all identities for “free Netflix trial”

Ransomware - Hold files hostage for payment to get back

Cyber Attacks and Cyber Warfare– Malware Designed to Harm or Deny Service to Physical Systems

Using Process Control (Water, Power, Traffic Management, etc.)– Financial Sector Attacks – Discrediting a Company, Service

Disruption of Exchanges and Banking– Discrediting Governments, Spoofing, Replay Attacks

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White-hat Sites, Historic Attackshttps://www.defcon.org/, Wikipedia Overview on DEF CONhttps://www.eff.org/, Wikipedia on EFFhttp://www.kali.org/ , BackTrack, Security Admin Tool for Analyzing Networks

Alleged Cyber-warfare attack – Stuxnet

Motor Vehicle Attack Analysis – Wired and Wireless– http://www.autosec.org/pubs/cars-oakland2010.pdf– https://www.youtube.com/watch?v=oqe6S6m73Zw– https://www.youtube.com/watch?v=bHfOziIwXic

Database Attacks – Typically Stolen Account Information– Playstation Attack April 17-19, 2011- Sony Blamed Anonymous, but

Not Clear Who did it!– JP Morgan Database Breach– Home Depot Breach– OPM Breach– Many More …

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Biggest Data Breaches

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2014-2016

Current (2017)

https://www.equifaxsecurity2017.com/consumer-notice/, https://www.wired.com/story/equifax-breach-no-excuse/

CybersecuritySome Databases for SOA (Service Oriented Architecture) with Cyberphysical Systems– Growing Trend for Intelligent Transportation and Vechicle

Telematics– E.g. On-Star System uses Oracle– DBMS Security not Just Records or Information Breaches

http://cybersecurity.ieee.org/

http://dev.mysql.com/doc/refman/5.0/en/security.html

http://dev.mysql.com/doc/refman/5.0/en/security-against-attack.html

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Best General DefensesEncryption Used for Authentication, Data Exchange (e.gSecure Sockets), and to Sign and Verify All Updates and Upgrades

Public Services, Ports, and Terminals Should be Limited– Only Necessary Services – SSH, SFTP– No Plaintext Services – FTP, Telnet

Routine Monitoring and Logging– Review all Connection Attempts and Login Attempts– Review Logs for Services that Crash and Restart– Installations, Updates, Upgrades– Signed Drivers– Modifications to Boot Code or CMOS/UEFI (Firmware)

Security Patches and Updates from Trusted Sources

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Inside ThreatsInsiders with Physical Access to Machines and Networking Equipment– Log all Entry / Exit to/from Data center and labs– Cross-checks and Need-to-Know Limited Distributions of

Sensitive Data– No Password Sharing, Guest or Anonymous Accounts– Delete Access and Accounts for Severed Relationships– VPN – Virtual Private Network Remote Access (Encrypted and

Tunnels for Data from Authenticated Client to Host over SSL)

Limit Data Removal on Media

File Permission and ACL (Access Control List) Maintenance Sam Siewert 16

Extreme ProtectionPrivate Network, No Public LANLimited Physical Access (Vault)Strong Encryption (E.g. AES 256 – FIPS-197, or Larger Keys)AES Validation, Validation ListMulti-method Authentication (Smartcard, Pass phrase, and Fingerprint)

Compartmentalization - Limit Knowledge of Why Work is Being Done (Hide Global Purpose)

Require Multiple Independent User Authentication –Combined Key or Pass Phrase Access that Requires Two Logins [E.g. mysql-workbench SSH tunnel]

Quotas on Bandwidth, Storage, Download, Session Time, Intrusion Detection Monitors, Port Monitors

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Encryption MethodsMathematical Hashing Functions

– One Way Hash Functions – Digital Signatures, Authentication codes, Hash tables, Fingerprints

– Not Reversible, but Valuable in Protocol

1 to 1 Transposition and Substitution Mapping Functions

Reversible Mathematical Transforms Y=f(X), X=f(Y)

Security Based on:1. Algorithm – E.g. AES, Rijndael, RSA, PGP, DES, Triple-DES, …2. Key Length (Bits), Cypher Block Chaining3. Key Exchange Protocol (Public or Private)

Sam Siewert 18http://www.snellgroup.com/documents/white-papers/white-paper-Good-Old-Mathematics.pdf

Basic Encryption - SubstitutionRe-map Alphabet, 1-to-1 and On-to (function)

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

ssiewert@ssiewert-VirtualBox:~/a320/crypto$ ./a.outA B C D E F G H I J K L M N O P Q R S T U V W X Y Z N A S I J K C M Q R F B D G H E L O P W T Z Y V U X TRANSLATE THIS!WONGPBNWJ WMQP!

BETA>INTRODUCTION TO COMPUTERSQGWOHITSWQHG WH SHDETWJOPINTRODUCTION TO COMPUTERS

BETA>abcdefghijklmnopqrstuvwxyzNASIJKCMQRFBDGHELOPWTZYVUXABCDEFGHIJKLMNOPQRSTUVWXYZ

BETA>exitJVQWEXIT

Basic Encryption - TranspositionPermute Text Block (e.g. up to 10 characters at a time)

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0 1 2 3 4 5 6 7 8 9

0 1 2 3 4 5 6 7 8 9

ssiewert@ssiewert-VirtualBox:~/a320/crypto$ ./a.out0123456789ABCD6275134908ABCD

TRAN>introduction to computersutcdnroiitc o ntopomutersintroduction to computers

TRAN>abcdefghijklmnopqrstuvwxyzgchfbdejaiqmrplnotksuvwxyzabcdefghijklmnopqrstuvwxyz

TRAN>exitexitexit

Basic Encryption – Early AutomationSubstitution with transposition – Enigma Code, U571

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ssiewert@ssiewert-VirtualBox:~/a320/crypto$ ./cryptA B C D E F G H I J K L M N O P Q R S T U V W X Y Z N A S I J K C M Q R F B D G H E L O P W T Z Y V U X TRANSLATE THIS!WONGPBNWJ WMQP!NNWBOGP WJWMQP!

CRYPT>abcdefghijklmnopqrstuvwxyzNASIJKCMQRFBDGHELOPWTZYVUXCSMKAIJRNQLDOEBGHWFPTZYVUX

CRYPT>introduction to computersQGWOHITSWQHG WH SHDETWJOPTWSIGOHQQWS H GWHEHDTWJOP

CRYPT>exitJVQWJVQW

Symmetric Key ConceptsEncryption KeysCan I encrypt and decrypt with the same key?

With the substitution Key, Yes

With the transposition Key, YesThis is a Symmetric Key System Sam Siewert 22

struct charmap submap[ALPHABET] ={

{'A','N'}, {'B','A'}, {'C','S'}, {'D','I'}, {'E','J'}, {'F','K'}, {'G','C'},{'H','M'}, {'I','Q'}, {'J','R'}, {'K','F'}, {'L','B'}, {'M','D'}, {'N','G'},{'O','H'}, {'P','E'}, {'Q','L'}, {'R','O'}, {'S','P'}, {'T','W'}, {'U','T'},{'V','Z'}, {'W','Y'}, {'X','V'}, {'Y','U'}, {'Z','X'}

};

// 0 1 2 3 4 5 6 7 8 9int transmap[BLOCK_SIZE]= {6, 2, 7, 5, 1, 3, 4, 9, 0, 8};int detransmap[BLOCK_SIZE]={8, 4, 1, 5, 6, 3, 0, 2, 9, 7};

Better Key Management?One Time Stack of Keys Exchanged in Private by Sender and Receiver in Advance– Agree to Use Different Symmetric Keys Based on

Day of Year or some Universal Coordination– Cycle Through 365 Different Keys

Attacker Can Still Capture Stack of Keys

Better Approach is a Public-Private Key System, E.g. PGPPublic Key SharedPublic Key Used to Encrypt Only (Digital Signature)Private Key Used to Decrypt Only (Authentication, Plaintext Recovery)Key Exchange Protocol and Key Rings

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http://en.wikipedia.org/wiki/Public-key_encryption

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Security for MySQL on PRClabLevel 1 – SSH Login and/or Tunnel Authentication

Level 2 – MySQL Authentication

Level 3 – MySQL Grants and Privileges by DB

E.g. SSH Tunnel Setup for mysql-workbench

Generate SSH Keys on PRClab for your account– In directory .ssh Copy and paste id_rsa contents into file on your

PC

– Start up mysql-workbench on your PC and set up SSH Tunnel using id_rsa private key on your PC

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Truncated for security purposes

SSH Tunnel Configuration

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SSH Tunnel

PRClabAccount

PRClabid_rsa

PRClabMySQLusername

SSH Tunnel Connection to DBEnter PRClabPassword

Enter MySQL PRClab Server Password

Now workbench is connected to PRClab MySQL Server over Tunnel

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SummaryTake a Cybersecurity Class – E.g. CI311 (Operations) and CS303 (Design/Implementation)

Tutorial Papers– Big Iron Lessons 5 & 6– http://www.snellgroup.com/documents/white-papers/white-paper-Good-

Old-Mathematics.pdf

In Practice Used by Egypt to Present Day – Cryptanalysis Time Should be Larger than the Time the Information is “Sensitive” or Private

Assume All Codes Can Eventually Be Broken with Sufficient Computing and Man-in-Middle Samples [Change Keys, Pass Phrases, Passwords, etc. Often]

Critical for Secure Military Communications – Considered a Munition, Export Controlled

Security Features Should Be Designed In and Patched Often as Threats Emerge Sam Siewert 28

Embry Riddle Courses to Go Deeper

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Take AwayEncryption– Substitution– Transposition – cypher blocks– Mathematical Basis (mapping functions, random

number generation, large hashing functions, one-way and reversible)

Secure Systems– Authorization– Authentication and Access Control– Denial of Service– Trojan Horses, Malware, Exploits [E.g. Buffer

Overflow] Sam Siewert 30

DBMS SECURITY NOTESC&B Reference - Chapter 20 - Security

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Chapter - Objectives

The scope of database security.

Why database security is a serious concern for an organization.

The type of threats that can affect a database system.

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Chapter - Objectives

How to protect a computer system using computer-based controls.

The security measures provided by Microsoft Office Access and Oracle DBMSs.

Approaches for securing a DBMS on the Web.

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Database Security

Data is a valuable resource that must be strictly controlled and managed, as with any corporate resource.

Part or all of the corporate data may have strategic importance and therefore needs to be kept secure and confidential.

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Database Security

Mechanisms that protect the database against intentional or accidental threats.

Security considerations do not only apply to the data held in a database. Breaches of security may affect other parts of the system, which may in turn affect the database.

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Database Security

Involves measures to avoid:– Theft and fraud– Loss of confidentiality (secrecy)– Loss of privacy– Loss of integrity– Loss of availability

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Database Security

Threat– Any situation or event, whether intentional or unintentional,

that will adversely affect a system and consequently an organization.

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Summary of Threats to Computer Systems

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Typical Multi-user Computer Environment

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Countermeasures – Computer-Based Controls

Concerned with physical controls to administrative procedures and includes: – Authorization– Access controls– Views– Backup and recovery– Integrity– Encryption– RAID technology

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Authorization– The granting of a right or privilege, which enables a subject

to legitimately have access to a system or a system’s object.– Authorization is a mechanism that determines whether a user

is, who he or she claims to be.

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Access control– Based on the granting and revoking of privileges. – A privilege allows a user to create or access (that is read,

write, or modify) some database object (such as a relation, view, and index) or to run certain DBMS utilities.

– Privileges are granted to users to accomplish the tasks required for their jobs.

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Most DBMS provide an approach called Discretionary Access Control (DAC).

SQL standard supports DAC through the GRANT and REVOKE commands.

The GRANT command gives privileges to users, and the REVOKE command takes away privileges.

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DAC while effective has certain weaknesses. In particular an unauthorized user can trick an authorized user into disclosing sensitive data.

An additional approach is required called Mandatory Access Control (MAC).

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DAC based on system-wide policies that cannot be changed by individual users.

Each database object is assigned a security class and each user is assigned a clearance for a security class, and rules are imposed on reading and writing of database objects by users.

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DAC determines whether a user can read or write an object based on rules that involve the security level of the object and the clearance of the user. These rules ensure that sensitive data can never be ‘passed on’ to another user without the necessary clearance.

The SQL standard does not include support for MAC.

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Popular Model for MAC (Mandatory Access Control) called Bell-LaPadula

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View– Is the dynamic result of one or more relational operations

operating on the base relations to produce another relation. – A view is a virtual relation that does not actually exist in the

database, but is produced upon request by a particular user, at the time of request.

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Backup– Process of periodically taking a copy of the database and

log file (and possibly programs) to offline storage media.

Journaling– Process of keeping and maintaining a log file (or journal)

of all changes made to database to enable effective recovery in event of failure.

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Integrity– Prevents data from becoming invalid, and hence giving

misleading or incorrect results.

Encryption– The encoding of the data by a special algorithm that renders

the data unreadable by any program without the decryption key.

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Setting the Insert, Select, and Update privileges

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DBMSs and Web Security

Internet communication relies on TCP/IP as the underlying protocol. However, TCP/IP and HTTP were not designed with security in mind. Without special software, all Internet traffic travels ‘in the clear’ and anyone who monitors traffic can read it.

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Must ensure while transmitting information over theInternet that:– inaccessible to anyone but sender and receiver

(privacy);– not changed during transmission (integrity);– receiver can be sure it came from sender

(authenticity);– sender can be sure receiver is genuine (non-

fabrication);– sender cannot deny he or she sent it (non-

repudiation).

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Measures include:– Proxy servers – Firewalls– Message digest algorithms and digital signatures– Digital certificates– Kerberos– Secure sockets layer (SSL) and Secure HTTP (S-

HTTP) – Secure Electronic Transactions (SET) and Secure

Transaction Technology (SST)– Java security– ActiveX security

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How Secure Electronic Transactions (SET) Works

CS317 File and Database Systemsmercury.pr.erau.edu/~siewerts/cs317/documents/Lectures/... · 2017....

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Transcript of CS317 File and Database Systemsmercury.pr.erau.edu/~siewerts/cs317/documents/Lectures/... · 2017....