SlideShare a Scribd company logo

Designing software with security in mind?

Omegapoint Academy, profile picture
Omegapoint Academy

Daniel Deogun emphasizes the importance of designing software with security in mind, arguing that good design principles can significantly reduce security flaws. He discusses various security challenges, including OWASP's top 10 vulnerabilities, and advocates for Domain Driven Security to tightly couple validation with data. The presentation also highlights the necessity of using prepared statements and emphasizes the concept of bounded contexts in Domain Driven Design for better handling of application complexity.

Software
Related topics:
Design Principles
1 of 63
Downloaded 20 times
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
#DevoxxPL @DanielDeogun Designing Software with Security in Mind? Daniel Deogun Omegapoint Platinum Sponsors:
About Me • Daniel Deogun • Sr Consultant, Omegapoint, Stockholm, Sweden • Started to play with Java in 1997 • Worked in various domains; • Medtech • Telecom • Gambling • Web • Strong advocate of DDD, TDD, and Domain Driven Security • Passionate about high quality software and design
Hypothesis “Crafting software with good design principles along with a security mindset, significantly reduces the number of security flaws in an application.” - Daniel Deogun
Important Questions ?
Important Questions ? What distinguishes secure software from insecure software?
Important Questions How should one treat legacy code? ? What distinguishes secure software from insecure software?
Important Questions How should one treat legacy code? ? What distinguishes secure software from insecure software? Is it really possible to design secure software?
Important Questions How should one treat legacy code? Is security a quality aspect or is quality a security aspect? ? What distinguishes secure software from insecure software? Is it really possible to design secure software?
OWASP top 10 A1 - Injection A2 - Broken Authentication and Session Management A3 - Cross-Site Scripting (XSS) A4 - Insecure Direct Object References A5 - Security Misconfiguration A6 - Sensitive Data Exposure A7 - Missing Function Level Access Control A8 - Cross-Site Request Forgery (CSRF) A9 - Using Components with Known Vulnerabilities A10 - Unvalidated Redirects and Forwards
OWASP top 10 A1 - Injection A3 - Cross-Site Scripting (XSS)
A1 - Injection “Injection flaws, such as SQL, OS, and LDAP injection occur when untrusted data is sent to an interpreter as part of a command or query. The attacker’s hostile data can trick the interpreter into executing unintended commands or accessing data without proper authorization.” - OWASP top 10
Example Address Regeringsgatan Street 56 Number 111 56 ZIP Code Stockholm City Sweden Country
The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff }
The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff } Examples of illegal input…
The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff } Examples of illegal input… register(“Regeringsgatan”, “56”, “111 56”, “Sweden”, “Stockholm”) Parameters swapped by mistakeIssue:
The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff } Examples of illegal input… register(“Regeringsgatan”, “or 1=1”, null, “Sweden”, “Stockholm”) Null parameters, SQL injection, illegal dataIssues:
The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff } Examples of illegal input… register(StringUtils.repeat("X", 999999999), “56”, “111 56”, “Stockholm”, “Sweden”) “Unbounded” inputIssue:
Treat it as a Validation Problem • Illegal data should be rejected through validation • White list input validation • Verify boundary conditions • Input is validated at each entry point • Create a strong security barrier [Bodiam Castle]
Validation Example public void register(String street, String number, String zip, String city, String country) { notNull(street); isTrue(street.length() < 101); matchesPattern("^[a-zA-Z åäöÅäö]{3,100}$", street); notNull(number); isTrue(number.length() < 4); matchesPattern("^[d]{1,3}[a-zA-Z]?$", number); notNull(zip); isTrue(zip.length() < 7); matchesPattern("^d{5}|(d{3} d{2})$", zip); //more validation… addressRepository.add(street + “ “ + number, zip, city, country); }
Treat it as a Validation Problem Upsides + Prevent illegal data from being processed + Detects illegal data as early as possible + Focuses on legal input values [Bodiam Castle]
Treat it as a Validation Problem Upsides + Prevent illegal data from being processed + Detects illegal data as early as possible + Focuses on legal input values [Bodiam Castle] Downsides - Validation and data are separated - Validation logic is often duplicated - Tends to focus on structural correctness and ignore invariants
Second Order Injection Flaw “An attack vector with structurally correct data that exploits missing invariant checks between input parameters or application state” - Daniel Deogun
Second Order Injection Flaw “An attack vector with structurally correct data that exploits missing invariant checks between input parameters or application state” - Daniel Deogun register(“Regeringsgatan”, “56”, “111 56”, “Gothenburg”, “Sweden”) Structurally correct but violates city - zip code invariantIssue:
Domain Driven Security • Founded by Dan Bergh Johnsson and Dr. John Wilander • Introduced at JavaPolis (later named Devoxx) in 2006 • Brings in the power of Domain Driven Design into the realm of security • All input data is mapped to value objects • Combines structural correctness and invariant checks • Validation and data are kept together [Matrix Code]
What’s the Meaning of the Address Data? 111 56 City reference in ZIP code Geographical Location 56 House number Street name Country
Conceptual Address Model Address City StreetName Number Country ZIP Code
Conceptual Address Model Address City StreetName Number Country ZIP Code • Invariants - City must exist in Country - Street must exist in City - Building with number must exist on street - ZIP code and City must match
public void register(String street, String number, String zip, String city, String country) { notNull(street); isTrue(street.length() < 101); matchesPattern("^[a-zA-Z åäöÅäö]{3,100}$", street); notNull(number); isTrue(number.length() < 4); matchesPattern("^[d]{1,3}[a-zA-Z]?$", number); notNull(zip); isTrue(zip.length() < 7); matchesPattern("^d{5}|(d{3} d{2})$", zip); //more validation… addressRepository.add(street + “ “ + number, zip, city, country); } Modeling Example
Modeling Example public class ZipCode { private final String value; public ZipCode(final String value) { this.value = validated(value); } private static String validated(final String value) { notNull(value); isTrue(value.length() < 7); matchesPattern("^d{5}|(d{3} d{2})$", value); return value; } //methods with domain logic… }
Modeling Example public class Address { private final Street street; private final BuildingNumber buildingNumber; private final ZipCode zipCode; private final City city; private final Country country; public Address(final Street street, final BuildingNumber buildingNumber, final ZipCode zipCode, final City city, final Country country) { this.street = notNull(street); this.buildingNumber = notNull(buildingNumber); this.zipCode = notNull(zipCode); this.city = notNull(city); this.country = notNull(country); validateInvariant(city, country); validateInvariant(street, city); validateInvariant(buildingNumber, street); validateInvariant(zipCode, city); }
Modeling Example public void register(final Street street, final BuildingNumber number, final Zip zip, final City city, final Country country) { notNull(street); notNull(number); notNull(zip); notNull(city); notNull(country); addressRepository.add(new Address(street, number, zip, city, country)); }
Treat it as a Modeling Problem and use DDS Upsides + Tight coupling between data and validation + Promotes white list validation and invariant checks + Use of domain objects reduces duplicated validation + Helps to prevent second order security weaknesses
Treat it as a Modeling Problem and use DDS Upsides + Tight coupling between data and validation + Promotes white list validation and invariant checks + Use of domain objects reduces duplicated validation + Helps to prevent second order security weaknesses Downsides - Involves business and domain experts - May seem less flexible - May cause problems with test data
What About Prepared Statements? • Are prepared statements redundant when using validated domain objects? Application
What About Prepared Statements? • Are prepared statements redundant when using validated domain objects? Application • So, yes we definitely should use prepared statements when interacting with a persistence context • Prepared statements separate syntactical constructs and data
A3 - XSS Cross Site Scripting “XSS flaws occur whenever an application takes untrusted data and sends it to a web browser without proper validation or escaping. XSS allows attackers to execute scripts in the victim’s browser which can hijack user sessions, deface web sites, or redirect the user to malicious sites.” - OWASP top 10
DDD - Bounded Contexts Shipping Context Customer Context Support Context
DDD - Bounded Contexts Shipping Context Customer Context Support Context • Bounded context is a central pattern in DDD • Trying to create one unified model of a large domain is bound to fail • Bounded contexts are DDD’s way of dealing with large domains • Mapping interrelationships between contexts is imperative since it reveals how data flows in the application
Example - Coder’s Blog • Let’s say we’re running a website where anyone can ask questions about code • Is it possible to avoid XSS?
Example - Coder’s Blog Stored XSS <script>alert(’42’)</script> Browser
Stored XSS & Broken Context Mapping <script>alert(’42’)</script> Write Context Read Context Browser
Preventing XSS • Context maps reveals how data flows between contexts • One cannot rely on white list validation since “evil input” is valid input • Proper escaping is needed in the read context to prevent data from the write context to be interpreted as code
The Reactive Manifesto • The Reactive Manifesto (http://www.reactivemanifesto.org/) • Reactive Systems are • Responsive • Resilient • Elastic • Message Driven
Responsive “The system responds in a timely manner if at all possible. … Responsive systems focus on providing rapid and consistent response times, establishing reliable upper bounds so they deliver a consistent quality of service. …” Reactive Systems
Resilient “The system stays responsive in the face of failure. … any system that is not resilient will be unresponsive after a failure. Resilience is achieved by replication, containment, isolation and delegation. Failures are contained within each component, isolating components from each other and thereby ensuring that parts of the system can fail and recover without compromising the system as a whole. …” Reactive Systems
Reactive Systems Elastic “The system stays responsive under varying workload. Reactive Systems can react to changes in the input rate by increasing or decreasing the resources allocated to service these inputs. This implies designs that have no contention points or central bottlenecks, resulting in the ability to shard or replicate components and distribute inputs among them. …”
It’s All About Feedback • The hacker needs feedback • A system that behaves strangely due to some input reveals its internal vulnerabilities • Let’s look at some good craftsmanship patterns…
Circuit Breakers “Circuit Breaker is the fundamental pattern for protecting your system from all manner of Integration Points problems.” - Michael T. Nygard, Release It!, April 2007
Bulkheads “Bulkheads are effective at maintaining service, or partial service, even in the face of failures. They are especially useful in service- oriented architectures, where the loss of a single service could have repercussions throughout the enterprise.” - Michael T. Nygard, Release It!, April 2007
Sensitive Value - One Time Read Only public final class SensitiveValue { private final AtomicReference<String> value; public SensitiveValue(final String value) { this.value = new AtomicReference<>(validated(value)); } private static String validated(final String value) { //Validation of input value return value; } public String value() { return notNull(value.getAndSet(null), "Sensitive value has already been consumed"); } @Override public boolean equals(final Object o) { throw new UnsupportedOperationException("Not allowed on sensitive value"); } @Override public int hashCode() { throw new UnsupportedOperationException("Not allowed on sensitive value"); } @Override public String toString() { return "SensitiveValue value = *****"; } }
“Evil” Test @RunWith(Theories.class) public class ValueObjectTest { private interface IllegalValue {String value();} @DataPoints public static IllegalValue[] input() { return new IllegalValue[]{ () -> null, () -> "", () -> " ", () -> "A", () -> "AA", () -> " AA ", () -> "1234567890", () -> "<script>alert('42')</script>", () -> "' or '1'='1" }; } @Rule public ExpectedException exception = ExpectedException.none(); @Theory public void should_be_illegal(final IllegalValue illegal) { exception.expect(ValidationException.class); new ValueObject(illegal.value()); }
Stack Traces java.sql.SQLException: Closed Connection at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:208) at oracle.jdbc.driver.PhysicalConnection.rollback(PhysicalConnection.java:1170) at org.apache.tomcat.dbcp.dbcp.DelegatingConnection.rollback(DelegatingConnection.java:368) at org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.rollback(PoolingDataSource.java:323) at net.sf.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:86) at org.springframework.orm.hibernate.HibernateTransactionManager.doRollback(HibernateTransactionManager.java:529) at org.springframework.transaction.support.AbstractPlatformTransactionManager.processRollback(AbstractPlatformTransact at org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(AbstractPlatformTransactionMana at org.springframework.transaction.interceptor.TransactionAspectSupport.completeTransactionAfterThrowing(TransactionAs
Stack Traces java.sql.SQLException: Closed Connection at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:208) at oracle.jdbc.driver.PhysicalConnection.rollback(PhysicalConnection.java:1170) at org.apache.tomcat.dbcp.dbcp.DelegatingConnection.rollback(DelegatingConnection.java:368) at org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.rollback(PoolingDataSource.java:323) at net.sf.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:86) at org.springframework.orm.hibernate.HibernateTransactionManager.doRollback(HibernateTransactionManager.java:529) at org.springframework.transaction.support.AbstractPlatformTransactionManager.processRollback(AbstractPlatformTransact at org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(AbstractPlatformTransactionMana at org.springframework.transaction.interceptor.TransactionAspectSupport.completeTransactionAfterThrowing(TransactionAs
Hide It! Oops! That’s embarrassing. We’ve seem to have made an error. Sorry for the inconvenience… [Head in Hands]
Legacy Code [Room in a mess]
Cyclomatic Complexity • Published in 1976 by Thomas J. McCabe “A Complexity Measure” i IEEE Transactions on Software Engineering, Vol. SE-2 No. 4 • A measurement of the number of linearly independent paths through a program's source code.
public void reserveRoomFor(String meeting, String owner, String roomName, Calendar start, Calendar end, String... invitees) { final List<Booking> bookings = repository.getBookingsFor(roomName); if(bookings != null && !bookings.isEmpty()) { for(Booking booking : bookings) { if(booking.collidesWith(new Booking(start, end, meeting, roomName, owner))) { throw new AlreadyReservedException(start, end, roomName, meeting, owner); } } } repository.store(new Booking(start, end, meeting, roomName, owner)); if(dispatcher == null) { dispatcher = Platform.instance().eventDispatcher(); } dispatcher.notify(invitees, new Booking(start, end, meeting, roomName, owner)); } Cyclomatic Complexity
Cyclomatic Complexity public void reserveRoomFor(final Meeting meeting, final Room room) { notNull(meeting); notNull(room); repository.store(booking(meeting, room)); dispatcher.notify(meeting.invitees, booking(meeting, room)); } private Booking booking(final Meeting meeting, final Room room) { return new Booking(meeting, room); }
Key Take Aways • Designing software is difficult • Security spans across the entire application while development tends to be from “top to bottom” in an application • By using good design principles, security becomes a natural part of development. Not a separate task.
Hypothesis “Crafting software with good design principles along with a security mindset, significantly reduces the number of security flaws in an application.” - Daniel Deogun
Hypothesis “Crafting software with good design principles along with a security mindset, significantly reduces the number of security flaws in an application.” - Daniel Deogun Plausible
Thanks @DanielDeogun
References • [Bodiam Castle - https://flic.kr/p/5BjV8] by Phillip Capper under license https://creativecommons.org/licenses/by/2.0/ • [Matrix Code - https://flic.kr/p/2Poor] by David.Asch under license https://creativecommons.org/licenses/by-nc-nd/2.0/ • [OWASP top 10] https://www.owasp.org/index.php/Top_10_2013-Top_10 • [Reactive Manifesto] http://www.reactivemanifesto.org/ • [Head in Hands - https://flic.kr/p/7p7raq] by Alex Proimos under license https://creativecommons.org/licenses/by-nc/2.0/ • [Questions - https://flic.kr/p/9ksxQa] by Damián Navas under license https://creativecommons.org/licenses/by-nc-nd/2.0/ • [Room in a mess - https://flic.kr/p/FSrZU] by yan yan under license https://creativecommons.org/licenses/by/2.0/ • [Historic Log Books - https://flic.kr/p/bjViT7] by PSNH under license https://creativecommons.org/licenses/by-nd/2.0/

More Related Content

PDF
Arm yourself with Domain Driven Security. It's time to slay some security trolls
Omegapoint Academy
 
PDF
Domain driven security_java_zone2016
Omegapoint Academy
 
PDF
Domain Driven Security Jfokus 2016
Omegapoint Academy
 
PDF
Fighting security trolls_with_high-quality_mindsets
ddeogun
 
PPTX
NoSQL Endgame LWJUG 2021
Thodoris Bais
 
PDF
[OPD 2019] Attacking JWT tokens
OWASP
 
PDF
Making Software Secure by Design
Omegapoint Academy
 
PPTX
Content OCRing and Scoring
Mauro Teixeira
 
Arm yourself with Domain Driven Security. It's time to slay some security trolls
Omegapoint Academy
 
Domain driven security_java_zone2016
Omegapoint Academy
 
Domain Driven Security Jfokus 2016
Omegapoint Academy
 
Fighting security trolls_with_high-quality_mindsets
ddeogun
 
NoSQL Endgame LWJUG 2021
Thodoris Bais
 
[OPD 2019] Attacking JWT tokens
OWASP
 
Making Software Secure by Design
Omegapoint Academy
 
Content OCRing and Scoring
Mauro Teixeira
 

What's hot (19)

PDF
Domain Primitives In Action - Explore DDD 2017
Omegapoint Academy
 
PPTX
Practical Cryptography and Security Concepts for Developers
Gökhan Şengün
 
PPTX
JWTs and JOSE in a flash
Evan J Johnson (Not a CISSP)
 
PPT
Steve Jones - Encrypting Data
Red Gate Software
 
PDF
Time-Based Blind SQL Injection Using Heavy Queries
Chema Alonso
 
PPT
Time-Based Blind SQL Injection using Heavy Queries
Chema Alonso
 
PPTX
MisuseCases
Greg Sternberg, MSc, CISSP
 
PPTX
Time-Based Blind SQL Injection
matt_presson
 
PPTX
Greensql2007
Kaustav Sengupta
 
PPTX
MongoDB Stich Overview
MongoDB
 
PPT
Sql Considered Harmful
coderanger
 
PDF
Not so blind SQL Injection
Francisco Ribeiro
 
PDF
The Unintended Risks of Trusting Active Directory
Will Schroeder
 
PDF
SQL Injection Tutorial
Magno Logan
 
PDF
DDS-Security Interoperability Demo - March 2018
Gerardo Pardo-Castellote
 
PDF
ReCertifying Active Directory
Will Schroeder
 
PDF
Neo4j Stored Procedure Training Part 1
Max De Marzi
 
PDF
2nd-Order-SQLi-Josh
Joshua S. Clark, CISSP
 
PDF
Managing your black friday logs - Code Europe
David Pilato
 
Domain Primitives In Action - Explore DDD 2017
Omegapoint Academy
 
Practical Cryptography and Security Concepts for Developers
Gökhan Şengün
 
JWTs and JOSE in a flash
Evan J Johnson (Not a CISSP)
 
Steve Jones - Encrypting Data
Red Gate Software
 
Time-Based Blind SQL Injection Using Heavy Queries
Chema Alonso
 
Time-Based Blind SQL Injection using Heavy Queries
Chema Alonso
 
MisuseCases
Greg Sternberg, MSc, CISSP
 
Time-Based Blind SQL Injection
matt_presson
 
Greensql2007
Kaustav Sengupta
 
MongoDB Stich Overview
MongoDB
 
Sql Considered Harmful
coderanger
 
Not so blind SQL Injection
Francisco Ribeiro
 
The Unintended Risks of Trusting Active Directory
Will Schroeder
 
SQL Injection Tutorial
Magno Logan
 
DDS-Security Interoperability Demo - March 2018
Gerardo Pardo-Castellote
 
ReCertifying Active Directory
Will Schroeder
 
Neo4j Stored Procedure Training Part 1
Max De Marzi
 
2nd-Order-SQLi-Josh
Joshua S. Clark, CISSP
 
Managing your black friday logs - Code Europe
David Pilato
 
Ad

Similar to Designing software with security in mind? (20)

PDF
Designing software with security in mind
Omegapoint Academy
 
PDF
Secure code
ddeogun
 
PDF
Secure by Design - Jfokus 2018 tutorial
Omegapoint Academy
 
PDF
GeeCon Prague 2017 - Cracking the Code to Secure Software
Daniel Sawano
 
PPT
Software Security Engineering
Marco Morana
 
PDF
Top 10 Bad Coding Practices Lead to Security Problems
Narudom Roongsiriwong, CISSP
 
PDF
Coding Security: Code Mania 101
Narudom Roongsiriwong, CISSP
 
PPTX
Modernizing, Migrating & Mitigating - Moving to Modern Cloud & API Web Apps W...
Security Innovation
 
PPTX
Eirtight writing secure code
Kieran Dundon
 
PDF
The Principles of Secure Development - BSides Las Vegas 2009
Security Ninja
 
PPTX
Secure Dot Net Programming
Adam Getchell
 
PDF
Secure Coding principles by example: Build Security In from the start - Carlo...
Codemotion
 
PDF
Protecting web apps
Omkar Parab
 
PDF
An Introduction to Secure Application Development
Christopher Frenz
 
PDF
Bringing the hacker mindset into requirements and testing by Eapen Thomas and...
QA or the Highway
 
PPTX
Code Review Cybersecurity: Comprehensive Guide to Secure Code Evaluation & B...
hamdi71
 
PPTX
DevBeat 2013 - Developer-first Security
Coverity
 
PDF
The Principles of Secure Development
Security Ninja
 
PPTX
Started In Security Now I'm Here
Christopher Grayson
 
PDF
Defensive Coding Crash Course Tutorial
Mark Niebergall
 
Designing software with security in mind
Omegapoint Academy
 
Secure code
ddeogun
 
Secure by Design - Jfokus 2018 tutorial
Omegapoint Academy
 
GeeCon Prague 2017 - Cracking the Code to Secure Software
Daniel Sawano
 
Software Security Engineering
Marco Morana
 
Top 10 Bad Coding Practices Lead to Security Problems
Narudom Roongsiriwong, CISSP
 
Coding Security: Code Mania 101
Narudom Roongsiriwong, CISSP
 
Modernizing, Migrating & Mitigating - Moving to Modern Cloud & API Web Apps W...
Security Innovation
 
Eirtight writing secure code
Kieran Dundon
 
The Principles of Secure Development - BSides Las Vegas 2009
Security Ninja
 
Secure Dot Net Programming
Adam Getchell
 
Secure Coding principles by example: Build Security In from the start - Carlo...
Codemotion
 
Protecting web apps
Omkar Parab
 
An Introduction to Secure Application Development
Christopher Frenz
 
Bringing the hacker mindset into requirements and testing by Eapen Thomas and...
QA or the Highway
 
Code Review Cybersecurity: Comprehensive Guide to Secure Code Evaluation & B...
hamdi71
 
DevBeat 2013 - Developer-first Security
Coverity
 
The Principles of Secure Development
Security Ninja
 
Started In Security Now I'm Here
Christopher Grayson
 
Defensive Coding Crash Course Tutorial
Mark Niebergall
 
Ad

More from Omegapoint Academy (7)

PDF
Domain Primitives in Action - DataTjej 2018
Omegapoint Academy
 
PDF
Designing Testable Software
Omegapoint Academy
 
PDF
Failing Continuous Delivery, Devoxx Poland, 2015
Omegapoint Academy
 
PPTX
Studentkonferens 2015 - Alla pratar om risker, men vad är det?
Omegapoint Academy
 
PDF
Studentkonferens 2015 1 + 1 = 1 (The Omegapoint Way)
Omegapoint Academy
 
PPTX
Studenkonferens 2015 - Craftsmanship
Omegapoint Academy
 
PPTX
Agile Enterprise: frukostseminarium
Omegapoint Academy
 
Domain Primitives in Action - DataTjej 2018
Omegapoint Academy
 
Designing Testable Software
Omegapoint Academy
 
Failing Continuous Delivery, Devoxx Poland, 2015
Omegapoint Academy
 
Studentkonferens 2015 - Alla pratar om risker, men vad är det?
Omegapoint Academy
 
Studentkonferens 2015 1 + 1 = 1 (The Omegapoint Way)
Omegapoint Academy
 
Studenkonferens 2015 - Craftsmanship
Omegapoint Academy
 
Agile Enterprise: frukostseminarium
Omegapoint Academy
 

Recently uploaded (20)

PDF
top salesforce developer skills in 2025.pdf
CloudMetic
 
PPTX
ai tools demonstartion for schools and inter college
harshavardhanreddyka11
 
PDF
How Creative Agencies Leverage Project Management Software.pdf
Orangescrum
 
PDF
EN-Survey-Report-SAP-LeanIX-EA-Insights-2025.pdf
deepakkhaitan3
 
PDF
Claude Code: Everyone is a 10x Developer - A Comprehensive AI-Powered CLI Tool
William Chong
 
PDF
PTS Company Brochure 2025 (1).pdf.......
pts464036
 
PPTX
Oracle E-Business Suite: A Comprehensive Guide for Modern Enterprises
Conacent Consulting
 
PPTX
Transform Your Business with a Software ERP System
Canada Software Company
 
PDF
Adobe Illustrator 28.6 Crack My Vision of Vector Design
ghrom2211g
 
PPTX
history of c programming in notes for students .pptx
Vijayakumari829030
 
PDF
Internet Downloader Manager (IDM) Crack 6.42 Build 42 Updates Latest 2025
itskinga12
 
PDF
AI in Product Development-omnex systems
omnex systems
 
PPTX
Agentic AI : A Practical Guide. Undersating, Implementing and Scaling Autono...
IT IDOL Technologies
 
PDF
Adobe Premiere Pro 2025 (v24.5.0.057) Crack free
ghrom2211g
 
PPTX
Agentic AI Use Case- Contract Lifecycle Management (CLM).pptx
mhxyzzp
 
PPTX
Introduction to Artificial Intelligence
lohedi9363
 
PDF
Design an Analysis of Algorithms II-SECS-1021-03
DilanEscobar1
 
PDF
Design an Analysis of Algorithms I-SECS-1021-03
DilanEscobar1
 
PDF
Which alternative to Crystal Reports is best for small or large businesses.pdf
Varsha Nayak
 
PDF
Understanding Forklifts - TECH EHS Solution
TECH EHS Solution
 
top salesforce developer skills in 2025.pdf
CloudMetic
 
ai tools demonstartion for schools and inter college
harshavardhanreddyka11
 
How Creative Agencies Leverage Project Management Software.pdf
Orangescrum
 
EN-Survey-Report-SAP-LeanIX-EA-Insights-2025.pdf
deepakkhaitan3
 
Claude Code: Everyone is a 10x Developer - A Comprehensive AI-Powered CLI Tool
William Chong
 
PTS Company Brochure 2025 (1).pdf.......
pts464036
 
Oracle E-Business Suite: A Comprehensive Guide for Modern Enterprises
Conacent Consulting
 
Transform Your Business with a Software ERP System
Canada Software Company
 
Adobe Illustrator 28.6 Crack My Vision of Vector Design
ghrom2211g
 
history of c programming in notes for students .pptx
Vijayakumari829030
 
Internet Downloader Manager (IDM) Crack 6.42 Build 42 Updates Latest 2025
itskinga12
 
AI in Product Development-omnex systems
omnex systems
 
Agentic AI : A Practical Guide. Undersating, Implementing and Scaling Autono...
IT IDOL Technologies
 
Adobe Premiere Pro 2025 (v24.5.0.057) Crack free
ghrom2211g
 
Agentic AI Use Case- Contract Lifecycle Management (CLM).pptx
mhxyzzp
 
Introduction to Artificial Intelligence
lohedi9363
 
Design an Analysis of Algorithms II-SECS-1021-03
DilanEscobar1
 
Design an Analysis of Algorithms I-SECS-1021-03
DilanEscobar1
 
Which alternative to Crystal Reports is best for small or large businesses.pdf
Varsha Nayak
 
Understanding Forklifts - TECH EHS Solution
TECH EHS Solution
 

Designing software with security in mind?

  • 1. #DevoxxPL @DanielDeogun Designing Software with Security in Mind? Daniel Deogun Omegapoint Platinum Sponsors:
  • 2. About Me • Daniel Deogun • Sr Consultant, Omegapoint, Stockholm, Sweden • Started to play with Java in 1997 • Worked in various domains; • Medtech • Telecom • Gambling • Web • Strong advocate of DDD, TDD, and Domain Driven Security • Passionate about high quality software and design
  • 3. Hypothesis “Crafting software with good design principles along with a security mindset, significantly reduces the number of security flaws in an application.” - Daniel Deogun
  • 5. Important Questions ? What distinguishes secure software from insecure software?
  • 6. Important Questions How should one treat legacy code? ? What distinguishes secure software from insecure software?
  • 7. Important Questions How should one treat legacy code? ? What distinguishes secure software from insecure software? Is it really possible to design secure software?
  • 8. Important Questions How should one treat legacy code? Is security a quality aspect or is quality a security aspect? ? What distinguishes secure software from insecure software? Is it really possible to design secure software?
  • 9. OWASP top 10 A1 - Injection A2 - Broken Authentication and Session Management A3 - Cross-Site Scripting (XSS) A4 - Insecure Direct Object References A5 - Security Misconfiguration A6 - Sensitive Data Exposure A7 - Missing Function Level Access Control A8 - Cross-Site Request Forgery (CSRF) A9 - Using Components with Known Vulnerabilities A10 - Unvalidated Redirects and Forwards
  • 10. OWASP top 10 A1 - Injection A3 - Cross-Site Scripting (XSS)
  • 11. A1 - Injection “Injection flaws, such as SQL, OS, and LDAP injection occur when untrusted data is sent to an interpreter as part of a command or query. The attacker’s hostile data can trick the interpreter into executing unintended commands or accessing data without proper authorization.” - OWASP top 10
  • 13. The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff }
  • 14. The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff } Examples of illegal input…
  • 15. The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff } Examples of illegal input… register(“Regeringsgatan”, “56”, “111 56”, “Sweden”, “Stockholm”) Parameters swapped by mistakeIssue:
  • 16. The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff } Examples of illegal input… register(“Regeringsgatan”, “or 1=1”, null, “Sweden”, “Stockholm”) Null parameters, SQL injection, illegal dataIssues:
  • 17. The Code… public void register(String street, String number, String zip, String city, String country) { //do stuff } Examples of illegal input… register(StringUtils.repeat("X", 999999999), “56”, “111 56”, “Stockholm”, “Sweden”) “Unbounded” inputIssue:
  • 18. Treat it as a Validation Problem • Illegal data should be rejected through validation • White list input validation • Verify boundary conditions • Input is validated at each entry point • Create a strong security barrier [Bodiam Castle]
  • 19. Validation Example public void register(String street, String number, String zip, String city, String country) { notNull(street); isTrue(street.length() < 101); matchesPattern("^[a-zA-Z åäöÅäö]{3,100}$", street); notNull(number); isTrue(number.length() < 4); matchesPattern("^[d]{1,3}[a-zA-Z]?$", number); notNull(zip); isTrue(zip.length() < 7); matchesPattern("^d{5}|(d{3} d{2})$", zip); //more validation… addressRepository.add(street + “ “ + number, zip, city, country); }
  • 20. Treat it as a Validation Problem Upsides + Prevent illegal data from being processed + Detects illegal data as early as possible + Focuses on legal input values [Bodiam Castle]
  • 21. Treat it as a Validation Problem Upsides + Prevent illegal data from being processed + Detects illegal data as early as possible + Focuses on legal input values [Bodiam Castle] Downsides - Validation and data are separated - Validation logic is often duplicated - Tends to focus on structural correctness and ignore invariants
  • 22. Second Order Injection Flaw “An attack vector with structurally correct data that exploits missing invariant checks between input parameters or application state” - Daniel Deogun
  • 23. Second Order Injection Flaw “An attack vector with structurally correct data that exploits missing invariant checks between input parameters or application state” - Daniel Deogun register(“Regeringsgatan”, “56”, “111 56”, “Gothenburg”, “Sweden”) Structurally correct but violates city - zip code invariantIssue:
  • 24. Domain Driven Security • Founded by Dan Bergh Johnsson and Dr. John Wilander • Introduced at JavaPolis (later named Devoxx) in 2006 • Brings in the power of Domain Driven Design into the realm of security • All input data is mapped to value objects • Combines structural correctness and invariant checks • Validation and data are kept together [Matrix Code]
  • 25. What’s the Meaning of the Address Data? 111 56 City reference in ZIP code Geographical Location 56 House number Street name Country
  • 27. Conceptual Address Model Address City StreetName Number Country ZIP Code • Invariants - City must exist in Country - Street must exist in City - Building with number must exist on street - ZIP code and City must match
  • 28. public void register(String street, String number, String zip, String city, String country) { notNull(street); isTrue(street.length() < 101); matchesPattern("^[a-zA-Z åäöÅäö]{3,100}$", street); notNull(number); isTrue(number.length() < 4); matchesPattern("^[d]{1,3}[a-zA-Z]?$", number); notNull(zip); isTrue(zip.length() < 7); matchesPattern("^d{5}|(d{3} d{2})$", zip); //more validation… addressRepository.add(street + “ “ + number, zip, city, country); } Modeling Example
  • 29. Modeling Example public class ZipCode { private final String value; public ZipCode(final String value) { this.value = validated(value); } private static String validated(final String value) { notNull(value); isTrue(value.length() < 7); matchesPattern("^d{5}|(d{3} d{2})$", value); return value; } //methods with domain logic… }
  • 30. Modeling Example public class Address { private final Street street; private final BuildingNumber buildingNumber; private final ZipCode zipCode; private final City city; private final Country country; public Address(final Street street, final BuildingNumber buildingNumber, final ZipCode zipCode, final City city, final Country country) { this.street = notNull(street); this.buildingNumber = notNull(buildingNumber); this.zipCode = notNull(zipCode); this.city = notNull(city); this.country = notNull(country); validateInvariant(city, country); validateInvariant(street, city); validateInvariant(buildingNumber, street); validateInvariant(zipCode, city); }
  • 31. Modeling Example public void register(final Street street, final BuildingNumber number, final Zip zip, final City city, final Country country) { notNull(street); notNull(number); notNull(zip); notNull(city); notNull(country); addressRepository.add(new Address(street, number, zip, city, country)); }
  • 32. Treat it as a Modeling Problem and use DDS Upsides + Tight coupling between data and validation + Promotes white list validation and invariant checks + Use of domain objects reduces duplicated validation + Helps to prevent second order security weaknesses
  • 33. Treat it as a Modeling Problem and use DDS Upsides + Tight coupling between data and validation + Promotes white list validation and invariant checks + Use of domain objects reduces duplicated validation + Helps to prevent second order security weaknesses Downsides - Involves business and domain experts - May seem less flexible - May cause problems with test data
  • 34. What About Prepared Statements? • Are prepared statements redundant when using validated domain objects? Application
  • 35. What About Prepared Statements? • Are prepared statements redundant when using validated domain objects? Application • So, yes we definitely should use prepared statements when interacting with a persistence context • Prepared statements separate syntactical constructs and data
  • 36. A3 - XSS Cross Site Scripting “XSS flaws occur whenever an application takes untrusted data and sends it to a web browser without proper validation or escaping. XSS allows attackers to execute scripts in the victim’s browser which can hijack user sessions, deface web sites, or redirect the user to malicious sites.” - OWASP top 10
  • 37. DDD - Bounded Contexts Shipping Context Customer Context Support Context
  • 38. DDD - Bounded Contexts Shipping Context Customer Context Support Context • Bounded context is a central pattern in DDD • Trying to create one unified model of a large domain is bound to fail • Bounded contexts are DDD’s way of dealing with large domains • Mapping interrelationships between contexts is imperative since it reveals how data flows in the application
  • 39. Example - Coder’s Blog • Let’s say we’re running a website where anyone can ask questions about code • Is it possible to avoid XSS?
  • 40. Example - Coder’s Blog Stored XSS <script>alert(’42’)</script> Browser
  • 41. Stored XSS & Broken Context Mapping <script>alert(’42’)</script> Write Context Read Context Browser
  • 42. Preventing XSS • Context maps reveals how data flows between contexts • One cannot rely on white list validation since “evil input” is valid input • Proper escaping is needed in the read context to prevent data from the write context to be interpreted as code
  • 43. The Reactive Manifesto • The Reactive Manifesto (http://www.reactivemanifesto.org/) • Reactive Systems are • Responsive • Resilient • Elastic • Message Driven
  • 44. Responsive “The system responds in a timely manner if at all possible. … Responsive systems focus on providing rapid and consistent response times, establishing reliable upper bounds so they deliver a consistent quality of service. …” Reactive Systems
  • 45. Resilient “The system stays responsive in the face of failure. … any system that is not resilient will be unresponsive after a failure. Resilience is achieved by replication, containment, isolation and delegation. Failures are contained within each component, isolating components from each other and thereby ensuring that parts of the system can fail and recover without compromising the system as a whole. …” Reactive Systems
  • 46. Reactive Systems Elastic “The system stays responsive under varying workload. Reactive Systems can react to changes in the input rate by increasing or decreasing the resources allocated to service these inputs. This implies designs that have no contention points or central bottlenecks, resulting in the ability to shard or replicate components and distribute inputs among them. …”
  • 47. It’s All About Feedback • The hacker needs feedback • A system that behaves strangely due to some input reveals its internal vulnerabilities • Let’s look at some good craftsmanship patterns…
  • 48. Circuit Breakers “Circuit Breaker is the fundamental pattern for protecting your system from all manner of Integration Points problems.” - Michael T. Nygard, Release It!, April 2007
  • 49. Bulkheads “Bulkheads are effective at maintaining service, or partial service, even in the face of failures. They are especially useful in service- oriented architectures, where the loss of a single service could have repercussions throughout the enterprise.” - Michael T. Nygard, Release It!, April 2007
  • 50. Sensitive Value - One Time Read Only public final class SensitiveValue { private final AtomicReference<String> value; public SensitiveValue(final String value) { this.value = new AtomicReference<>(validated(value)); } private static String validated(final String value) { //Validation of input value return value; } public String value() { return notNull(value.getAndSet(null), "Sensitive value has already been consumed"); } @Override public boolean equals(final Object o) { throw new UnsupportedOperationException("Not allowed on sensitive value"); } @Override public int hashCode() { throw new UnsupportedOperationException("Not allowed on sensitive value"); } @Override public String toString() { return "SensitiveValue value = *****"; } }
  • 51. “Evil” Test @RunWith(Theories.class) public class ValueObjectTest { private interface IllegalValue {String value();} @DataPoints public static IllegalValue[] input() { return new IllegalValue[]{ () -> null, () -> "", () -> " ", () -> "A", () -> "AA", () -> " AA ", () -> "1234567890", () -> "<script>alert('42')</script>", () -> "' or '1'='1" }; } @Rule public ExpectedException exception = ExpectedException.none(); @Theory public void should_be_illegal(final IllegalValue illegal) { exception.expect(ValidationException.class); new ValueObject(illegal.value()); }
  • 52. Stack Traces java.sql.SQLException: Closed Connection at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:208) at oracle.jdbc.driver.PhysicalConnection.rollback(PhysicalConnection.java:1170) at org.apache.tomcat.dbcp.dbcp.DelegatingConnection.rollback(DelegatingConnection.java:368) at org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.rollback(PoolingDataSource.java:323) at net.sf.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:86) at org.springframework.orm.hibernate.HibernateTransactionManager.doRollback(HibernateTransactionManager.java:529) at org.springframework.transaction.support.AbstractPlatformTransactionManager.processRollback(AbstractPlatformTransact at org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(AbstractPlatformTransactionMana at org.springframework.transaction.interceptor.TransactionAspectSupport.completeTransactionAfterThrowing(TransactionAs
  • 53. Stack Traces java.sql.SQLException: Closed Connection at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146) at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:208) at oracle.jdbc.driver.PhysicalConnection.rollback(PhysicalConnection.java:1170) at org.apache.tomcat.dbcp.dbcp.DelegatingConnection.rollback(DelegatingConnection.java:368) at org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.rollback(PoolingDataSource.java:323) at net.sf.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:86) at org.springframework.orm.hibernate.HibernateTransactionManager.doRollback(HibernateTransactionManager.java:529) at org.springframework.transaction.support.AbstractPlatformTransactionManager.processRollback(AbstractPlatformTransact at org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(AbstractPlatformTransactionMana at org.springframework.transaction.interceptor.TransactionAspectSupport.completeTransactionAfterThrowing(TransactionAs
  • 54. Hide It! Oops! That’s embarrassing. We’ve seem to have made an error. Sorry for the inconvenience… [Head in Hands]
  • 56. Cyclomatic Complexity • Published in 1976 by Thomas J. McCabe “A Complexity Measure” i IEEE Transactions on Software Engineering, Vol. SE-2 No. 4 • A measurement of the number of linearly independent paths through a program's source code.
  • 57. public void reserveRoomFor(String meeting, String owner, String roomName, Calendar start, Calendar end, String... invitees) { final List<Booking> bookings = repository.getBookingsFor(roomName); if(bookings != null && !bookings.isEmpty()) { for(Booking booking : bookings) { if(booking.collidesWith(new Booking(start, end, meeting, roomName, owner))) { throw new AlreadyReservedException(start, end, roomName, meeting, owner); } } } repository.store(new Booking(start, end, meeting, roomName, owner)); if(dispatcher == null) { dispatcher = Platform.instance().eventDispatcher(); } dispatcher.notify(invitees, new Booking(start, end, meeting, roomName, owner)); } Cyclomatic Complexity
  • 58. Cyclomatic Complexity public void reserveRoomFor(final Meeting meeting, final Room room) { notNull(meeting); notNull(room); repository.store(booking(meeting, room)); dispatcher.notify(meeting.invitees, booking(meeting, room)); } private Booking booking(final Meeting meeting, final Room room) { return new Booking(meeting, room); }
  • 59. Key Take Aways • Designing software is difficult • Security spans across the entire application while development tends to be from “top to bottom” in an application • By using good design principles, security becomes a natural part of development. Not a separate task.
  • 60. Hypothesis “Crafting software with good design principles along with a security mindset, significantly reduces the number of security flaws in an application.” - Daniel Deogun
  • 61. Hypothesis “Crafting software with good design principles along with a security mindset, significantly reduces the number of security flaws in an application.” - Daniel Deogun Plausible
  • 63. References • [Bodiam Castle - https://flic.kr/p/5BjV8] by Phillip Capper under license https://creativecommons.org/licenses/by/2.0/ • [Matrix Code - https://flic.kr/p/2Poor] by David.Asch under license https://creativecommons.org/licenses/by-nc-nd/2.0/ • [OWASP top 10] https://www.owasp.org/index.php/Top_10_2013-Top_10 • [Reactive Manifesto] http://www.reactivemanifesto.org/ • [Head in Hands - https://flic.kr/p/7p7raq] by Alex Proimos under license https://creativecommons.org/licenses/by-nc/2.0/ • [Questions - https://flic.kr/p/9ksxQa] by Damián Navas under license https://creativecommons.org/licenses/by-nc-nd/2.0/ • [Room in a mess - https://flic.kr/p/FSrZU] by yan yan under license https://creativecommons.org/licenses/by/2.0/ • [Historic Log Books - https://flic.kr/p/bjViT7] by PSNH under license https://creativecommons.org/licenses/by-nd/2.0/