Build secure .NET/C# code to meet ISA/IEC 62443 by adopting a Secure Development Lifecycle (SDL), using proven libraries for encoding, crypto, auth, and static analysis, and mapping your SDL to ISA/IEC 62443-4-1 requirements (design, implementation, verification, maintenance). Start with the ISA/IEC 62443 SDL requirements, apply Microsoft .NET secure-coding guidance, and use libraries such as BouncyCastle (crypto), Microsoft AntiXSS, Duende IdentityServer (auth), plus Roslyn analyzers and SonarQube for automated verification.
Preparing the Secure Codes by adopting Secure product development lifecycle: define security requirements, threat model, secure design, secure implementation (coding rules), verification (testing/pen tests), and maintenance/patching processes. When we discuss the ISA 62443 what we need to prepare is:
- Requirements & threat modeling: capture product security requirements and threat models early; record them in your backlog and link to code changes (62443 SR/SD clauses).
- Secure design: apply defense-in-depth, least privilege, and secure defaults; avoid unsafe APIs and binary formatters in .NET.
- Secure implementation (coding rules): validate and sanitize inputs, use parameterized DB access, avoid hard-coded secrets, use safe cryptography primitives, and avoid unsafe/unsafe-code unless strictly necessary.
- Verification: integrate static analysis, dependency-vulnerability scanning, unit tests for security controls, fuzzing and independent penetration testing.
- Maintenance: CVE tracking, signed updates, and timely patch delivery per 62443 update requirements.
After doing the process, we can prepare several libraries such as
- Bouncycastle. for encrypting and decrypting your custom data.
- Microsoft AntiXSS / System.Web.Security.AntiXss, for avoid XSS
- ASP.NET core identity, centralized authentication
- Roslyn analyzers, finding insecire API, hardcoded cryptos, and weak crypto.
- SonarQube, track security debt and quality gates
In practical implementation, below is the steps:
- Adopt an SDL aligned to ISA/IEC 62443-4-1 and document SM/SD/SI/SV/SUM processes.
- Use Microsoft secure-coding guidance: avoid binary formatters, validate inputs server-side, use secure APIs.
- Encoding & sanitization: use AntiXSS for HTML/JS/CSS encoding and sanitization of user content.
- Cryptography: prefer platform crypto (System.Security.Cryptography) and use BouncyCastle when advanced algorithms or PQC are needed.
- Authentication/authorization: implement OAuth2/OIDC with Duende IdentityServer and ASP.NET Core Identity for robust token management.
- Automate verification: add Roslyn analyzers and SecurityCodeScan to dev builds; run SonarQube in CI to enforce gates.
- Supply-chain & patching: maintain a component inventory, scan NuGet dependencies, and document update delivery per 62443 maintenance requirements.