CSC 2045 Secure Software Principles Week 02

Course Information

• Course Title: Secure Software Principles
• Course Code: CSC 2045

Objectives

• Understand why vulnerabilities exist in programming code.
• Learn standard software engineering and software assurance principles for secure software development.

Agenda: Week 02

• Secure Coding
• Secure Fundamentals
• Principles of Security
• SDLC
• Good Programming, Coding Standards & Practices

Secure Coding in C/C++

• Read the Forward (page xvii) from the book Secure Coding C/C++ by Robert Seacord.
• Reference: https://insights.sei.cmu.edu/documents/1312/2005_009_001_52710.pdf

OWASP Secure Fundamentals

• Read the OWASP Developer Guide on Secure Fundamentals.
• Reference: https://owasp.org/www-project-developer-guide/draft/foundations/security_fundamentals/
• Define CIA (Confidentiality, Integrity, Availability) and AAA (Authentication, Authorization, Accounting).

OWASP Principles of Security

• Read the OWASP Developer Guide on Security Principles.
• Reference: https://owasp.org/www-project-developer-guide/draft/foundations/security_principles/
• Understand the outlined security principles.

OWASP Secure Development & Integration

• Read the OWASP Developer Guide on Secure Development & Integration.
• Reference: https://owasp.org/www-project-developer-guide/draft/foundations/secure_development/
• Define SDLC (Software Development Life Cycle).

Why Do We Need SDLC?

• Software provides automation, intelligence, and functionality.
• Software takes input and produces output.
• Unexpected input can lead to unexpected interactions among components.
• Automation, intelligence, and functionality create potential risks, including privacy issues, unauthorized actions (like alteration or privilege escalation through buffer overflow).
• Understanding software security is crucial.
• Managing these risks is essential.

Software Development Lifecycle (SDLC)

• Phase 1: Define the Problem: Analyze and specify the requirements for the problem.
• Phase 2: Design the Solution: Defining the algorithm to solve the particular problem
• Phase 3: Implement/Code Solution: Creating the program's solution.
• Phase 4: Testing: Verifying the correctness and effectiveness, and identifying potential errors in the program.
• Phase 5: Deploy/Maintain & Document: Deploying it to the intended environment and maintaining its functionality afterward (documentation is essential).

Analysis and Requirements

• What?
  • Define the problem.
  • Understand the requirements.
• Most common cause of system failures: Tracing failures to inadequate requirements gathering.
• Document the problem statement precisely.
• Use cases.
• Threat modeling.
• Important point: Consider security in this phase.

Design

• How? Planning, Algorithms, and Code Responsibility
• Consider vulnerabilities and apply security principles.

Implementation

• Choose a programming language (consider security).
• Code Responsibly. Apply software security principles. Understand syntax errors vs. logic errors.
• Code reviews and static analysis.
• Important point: Consider security during implementation.

Safe Coding: Threat Modeling 101

• STRIDE Threat Model:
  • Spoofing: Unauthorized access masquerading as another user.
  • Tampering: Unauthorized changes to data or functionality.
  • Repudiation: Inability to confirm actions.
  • Information Disclosure: Revealing confidential information.
  • Denial of Service (DoS): Preventing legitimate users from accessing resources.
  • Elevation of Privilege: Unauthorized increase in permissions.
  • Other considerations include Confidentiality, Integrity, Availability, Identification/Authentication, Authorization, and Auditing.

Threats and Mitigation Techniques

• Spoofing Identity: Compromising authentication, protecting keys, and passwords.
• Tampering with Data: Compromising integrity.
• Repudiation: Logging, audit trails, and digital signatures.
• Information Disclosure: Compromising confidentiality, access control, and encryption.
• Denial of Service: Compromising availability, graceful degradation, filtering, increasing server resources.
• Elevation of Privilege: Access control and sandboxing.

Common Code Vulnerabilities

• Incorrect or incomplete input validation
• Poor or missing exception handling
• Buffer overflows
• Race conditions
• SQL injection
• Cross-side scripting
• Common Vulnerabilities (additional): The document lists several other Common Weakness Enumeration (CWE) vulnerabilities with year-over-year trends, including CWE-20, CWE-119, CWE-434, CWE-22, CWE-89, etc. Studying these and their trends is essential.

Good Programming

• Focus on both problem solving and precise solutions.
• Programs should be readable by humans, with attention given to the design, to be easily executed by the machine later.
• This is vital for good programming practices.
• Consider these points as you develop new code.

Why Write Insecure Code?

• Read the given web link (https://dwheeler.com/secure-programs/Secure-Programs-HOWTO/why-write-insecure.html) and discuss the reasons for creating insecure code.
• Answer questions in the PearDeck format about the items in the article, and your opinions about them.

Good Programming style

• Code is read more than written.
• Code consistency.
• Code clarity.
• Code formatting.

C++ Coding Standards

• Coding standards for a particular environment using C++. There is no completely universal standard for all environments, since the uses for C++ are too varied.
• Guidelines for using using namespace std. Avoid using using namespace std; in your code.
• Guidelines for local variable declarations. Declaring variables at the top of the function scope is generally preferred.
• Important point: C++ Coding Standards are important for consistent software designs and maintenance; no single standard applies to all use-cases.
• Guidelines for variable naming. Use descriptive and meaningful names that clearly indicate the purpose of the variable.
• Guidelines for global variables. Minimize the usage of global variables whenever possible.