The Software Development Life Cycle (SDLC) is a structured methodology used by developers to create high-quality software. Incorporating security measures at each stage of the SDLC not only ensures the creation of safer applications but also saves time and resources in the long run. As the adage goes, \”A stitch in time saves nine.”
This blog aims to shed light on integrating security practices in each phase of the SDLC and introduces the concept of maturity metrics to evaluate the effectiveness of security integrations.
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Analysis:
In this initial stage, a thorough examination of the existing system or process is undertaken, pinpointing deficiencies and defining the desired operational parameters and outcomes.
it’s imperative to identify and document security requirements alongside functional requirements. Understanding the data flow, identifying potential security risks, and compliance requirements are crucial.
Engaging in discussions with the primary users of the upcoming app, along with obtaining approval from senior leaders, is imperative. Developers should draft a presentation for senior IT and organizational heads to garner support for the project.
Planning and Requirements
Upon project approval, the task at hand is to delineate the new system\’s features and capabilities. Drafting a project plan is crucial at this juncture, with developers articulating how the identified deficiencies will be tackled in the new setup. Utilizing a spreadsheet or project management software to structure the project plan, inclusive of sub-activities within each primary step, is advisable.
Security Measures to Consider:
- Conducting Threat Modeling: Threat modeling is a systematic process used in identifying and evaluating the potential threats and vulnerabilities that could affect a system or application. such activity help developers and security teams better understand the security risks they might face and can thus design the system with appropriate security controls to mitigate these risks. The process involves identifying potential threat agents, methods they might use to attack the system, and the impact of successful attacks.
- Identifying Compliance Requirements : Compliance requirements refer to the legal and regulatory obligations that a company or application needs to adhere to. For instance: GDPR (General Data Protection Regulation)
Design:
In the design phase, the architectural framework of the application is laid out, it is a critical part of SDLC as it lays the groundwork for how the software application will be realized.
The design phase is quintessential as it transforms the requirements into a format that can be implemented by the software development team in the subsequent phases. This phase sets the stage for the construction of the software system and is key to ensuring the system is structured in a way that meets the project objectives while staying within scope and budget. It’s the right time to integrate security controls and ensure they align with the overall design.
- Understanding Requirements:
- Before embarking on the design process, it\’s essential to have a solid understanding of the requirements gathered during the previous phase (requirements gathering and analysis). This understanding helps in developing a design that meets all the stipulated requirements.
- System Architecture Design:
- In this step, the overall system architecture is designed. This architecture provides the structure of the system and models how different parts of the system will interact with each other.
- Detailed Design:
- Detailed design involves diving deeper into the architectural design to create detailed specifications for each component of the system. This includes designing the database, defining the user interface, setting up network communications, and other technical specifications.
- Interface Design:
- Designing the interfaces between different system components, including user interfaces and the interfaces between different software modules, is crucial for ensuring smooth interaction within the software system.
- Database Design:
- The structure of the database is designed during this stage. It involves defining how data will be stored, accessed, managed, and updated within the system.
- Security Design:
- Considering the security aspects of the application is crucial. This includes designing the authorization, authentication, data encryption, and audit trails to ensure the security of the data and the system.
- Explicitly design the authorization, authentication, data encryption, and audit trails to ensure the security of the data and the system.
- Secure Design Reviews: Conduct reviews of the design from a security perspective to identify any potential weaknesses or vulnerabilities.
- Architecture Risk Analysis: Perform a risk analysis on the architecture to identify and address potential security risks.
- Creating Design Documents:
- All design decisions and blueprints are documented thoroughly. These design documents serve as guides for the developers, and also as references for future maintenance work.
- Review and Approval:
- The design needs to be reviewed by stakeholders, and possibly a governing body, to ensure it meets the requirements and adheres to the necessary standards. Necessary adjustments are made based on feedback, and once everyone is satisfied, the design is approved and development can commence.
- Tool Selection:
- Selecting the appropriate development tools, technologies, and platforms that will be used for building the application is also part of the design phase.
- Prototyping:
- In some models of SDLC, prototyping is used as a part of the design phase to provide a visual model or a working model (prototype) of the system to the stakeholders before actual development begins.
Implementation:
Engage in program designs utilizing internal or external software teams, software development tools, and other resources as necessary.
This phase involves actual coding where developers must adhere to secure coding practices to prevent common vulnerabilities. Key considerations such as initial testing, user training, deployment strategies, acceptance testing, and management approval should be meticulously defined and documented.
The implementation or development phase is where the actual coding and building of the system take place. It\’s a crucial stage where the designs are translated into the actual software. Here’s a breakdown of the implementation phase of the SDLC with a focus on security:
- Setting up Environment:
- Establish a secure development environment to ensure that the software is being built and tested in a controlled and secure setting.
- Coding:
- Write the code according to the specifications detailed in the design phase.
- Ensure to follow secure coding practices to prevent vulnerabilities.
- Utilize secure coding guidelines and adhere to coding standards which emphasize security.
- Security Measures:
- Secure Code Reviews: Regularly review the code for potential security issues, either manually or using automated security scanning tools.
- Static Application Security Testing (SAST): Employ static analysis tools to analyse the source code for security vulnerabilities without executing the code.
- Dependency Scanning: Check third-party libraries and dependencies for known security vulnerabilities.
- Unit Testing:
- Conduct unit tests to ensure each part of the software works as intended.
- Include security-focused unit tests to validate the security features of the application.
- Integration:
- Integrate the various components of the software, ensuring that they work together as expected.
- Conduct security tests to ensure that the integration points do not introduce security vulnerabilities.
- Integration Testing:
- Test the integrated system for functionality and security.
- Ensure that security features function correctly after integration.
- Security Training:
- Provide training for developers on secure coding practices to minimize the introduction of security flaws.
- Documentation:
- Document the code, the system architecture, and the security measures implemented.
- Ensure that the documentation provides clear guidance on how to maintain and operate the system securely.
- Quality Assurance:
- Ensure that the developed software meets all requirements, including security requirements.
- Conduct thorough testing, both functional and security-focused, to identify and fix any issues before moving to the next phase.
- Continuous Monitoring:
- Set up monitoring tools to continuously monitor the security of the application during the development.
- Detect and respond to any security incidents swiftly.
- Version Control:
- Use version control systems to track changes to the codebase and ensure that security fixes and improvements are correctly implemented and documented.
The implementation phase is not only about developing the functionalities but ensuring that security is integrated into the code to protect the application from potential threats. Through careful coding practices, regular security testing, and thorough documentation, a secure foundation is laid for the software that will contribute to its overall resilience against security threats in subsequent phases of the SDLC.
Verification:
Following the completion of the initial system, a spectrum of tests is required to ascertain performance, user interaction ease, communications efficiency, and security robustness. Address any issues emerging from the testing and retest the rectifications. Incorporating Quality Assurance (QA) teams in this stage is beneficial.
Verification in the SDLC is a process that helps to ensure the quality and correctness of the software being developed. This phase aims to verify whether the software meets the specified requirements and is free from bugs to a defined level of confidence. Here are the key aspects of the verification phase:
- Static Testing:
- This involves examining the software documentation and code without executing the program.
- Techniques include reviews, walkthroughs, and inspections to find errors, code smells, or any discrepancies in the documentation.
- Dynamic Testing:
- This involves executing the software and analyzing the outputs.
- Common dynamic testing methods include unit testing, integration testing, system testing, and acceptance testing.
- Code Reviews:
- Reviewing the code to ensure it follows the coding standards, is well-structured, and free from bugs.
- Peer reviews and automated code reviews can be utilized for this purpose.
- Automated Testing:
- Using automated testing tools to perform repetitive and extensive testing to catch bugs and ensure the software behaves as expected.
- Automated tests can be run as part of a Continuous Integration/Continuous Deployment (CI/CD) pipeline.
- Manual Testing:
- Testers execute the software manually to find bugs and verify the system’s behavior against the defined requirements.
- Manual testing is often used for exploratory testing, usability testing, and when automated testing is not feasible.
- Requirements Traceability:
- Ensure that all the requirements have been implemented correctly by tracing each requirement to corresponding parts of the implementation.
- Helps in verifying that nothing has been missed and everything has been implemented as per the expectations.
- Performance Testing:
- Ensuring the software performs well under the expected workload.
- Includes stress testing, load testing, and scalability testing.
- Security Testing:
- Ensuring the software is secure and free from vulnerabilities.
- It includes checking for common vulnerabilities, ensuring proper authentication and authorization, and verifying data protection measures.
- Compatibility and Compliance Testing:
- Ensure the software is compatible with other systems, platforms, and complies with any regulatory requirements.
- User Acceptance Testing (UAT):
- Obtaining validation from the end-users that the software meets their expectations and the specified requirements.
- Feedback from UAT can be used to make necessary adjustments before the software is moved to the production environment.
- Regression Testing:
- Checking that recent changes or bug fixes haven\’t adversely affected existing features.
- It ensures that the previously developed and tested software still works after a change.
- Documentation:
- Ensuring all the necessary documentation is updated and reflects the current state of the software.
Verification is a critical phase that helps to identify bugs and issues early in the SDLC, which in turn contributes to the production of high-quality, reliable, and secure software.
As part of the earlier design phase, fabricate a deployment schedule. Given the system\’s complexity, a phased rollout might be more suitable compared to a single launch, enabling users to acclimate to the system in a conducive environment. Operating the existing system in parallel with the new one may ease the transition.
During this phase, crafting training programs and documentation for primary and alternate users is essential. Arranging a training session with multiple workstations connected to both systems can facilitate users in understanding the differences between the old and new systems.
Maintenance:
Continuous monitoring of the new system\’s performance is vital, and any necessary updates should be carried out without severely disrupting production. Draft a schedule for patch deployments, system shutdowns for maintenance, hardware updates, and cybersecurity along with disaster recovery undertakings.
Maintenance is a vital phase in the Software Development Life Cycle (SDLC) that occurs post-deployment of the system. It ensures that the system continues to meet its objectives and performance standards. Here are the key components and considerations involved in the maintenance phase:
- Corrective Maintenance:
- This involves fixing bugs and other issues that were not discovered during earlier stages of testing.
- It also includes making necessary corrections to ensure the system\’s performance remains efficient and reliable.
- Adaptive Maintenance:
- This involves making adjustments to the system to cope with changes in the environment, such as updating the system to work with a new operating system or hardware.
- It helps to ensure the software remains effective in a changing technological landscape.
- Perfective Maintenance:
- This is concerned with improving system performance, enhancing functionalities, and making the system easier to use.
- This could include redesigning certain elements of the system to improve user satisfaction.
- Preventive Maintenance:
- This involves identifying and addressing potential issues before they become actual problems.
- It might include code optimization, code cleanup, and documentation update to prevent future issues and improve software understandability and maintainability.
- Routine Maintenance:
- Routine checks and minor modifications to ensure the system is operating efficiently and effectively.
- This can also include backup and recovery operations to safeguard against data loss.
- Security Maintenance:
- Continually monitoring and updating security protocols to protect the system against threats.
- This also includes patching vulnerabilities, updating security certificates, and ensuring that the system complies with the latest security standards and regulations.
- User Feedback:
- Gathering feedback from users to understand their experiences, identify areas for improvement, and make necessary adjustments to meet user needs and expectations.
- Monitoring and Performance Tuning:
- Constantly monitoring the system\’s performance and making necessary optimizations to ensure that it meets the desired performance metrics.
- Legal and Compliance Updates:
- Ensuring the software remains compliant with changing laws, regulations, and standards is critical to avoid legal issues.
- Documentation:
- Updating documentation to reflect changes made during the maintenance phase which is essential for future reference and for maintaining a clear understanding of the system\’s current state.
Maturity Metrics in-depth:
Maturity metrics provide a means to evaluate the effectiveness and maturity of security practices across the SDLC.
| SDLC Phase | Maturity Metrics |
| Planning and Requirements | Percentage of identified security requirements. Documented data classification and handling procedures. |
| Design | Number of unresolved high-risk design issues. Level of adherence to secure design principles. |
| Implementation | Number of discovered and unresolved coding vulnerabilities. Adherence rate to secure coding standards. |
| Verification | Number of unresolved security issues. Percentage of critical vulnerabilities mitigated. |
| Maintenance | Time taken to resolve identified vulnerabilities. Number of security incidents reported post-deployment. |
For instance, a low number of unresolved design issues or coding vulnerabilities could indicate a mature security posture during the Design and Implementation phases respectively.
Examples:
- Company A conducts bi-annual penetration tests and resolves identified vulnerabilities within a month. This practice reflects a mature security verification process.
- Company B lacks a patch management process, leading to a high number of reported security incidents post-deployment, indicating room for improvement in the Maintenance phase.
Conclusion
This roadmap outlines how integrating security into the fabric of the SDLC and evaluating the process using maturity metrics can result in superior, safer applications. As the dynamics of cyber threats continue to evolve, having a well-rounded security protocol within the SDLC is no longer a luxury but a necessity for every development project.