stronglink/SUBSTANCE.md at master · btrask/stronglink

Abstraction: Practical C code quality and security guidelines with rationale

Key points:

• Secure C programs are feasible up to ~25-50KLOC; beyond that complexity makes auditing intractable; keeping code small is the single best security practice
• Memory: always use calloc over malloc, null pointers immediately after free, use explicit_bzero() for sensitive buffers, avoid custom allocators
• Error handling should be ubiquitous; prefer single-line checks (if(rc < 0) return rc;) to keep them readable and encourage their use
• String safety: use strlcpy/strlcat (OpenBSD), snprintf over sprintf, always pass string literals as format strings to prevent format-string exploits
• Build with -Wall -Wextra -Werror -Wwrite-strings; use sanitizers (Valgrind), fuzzing (AFL), and static analyzers
• Reference exemplary codebases: SQLite (gold standard), PostgreSQL, OpenBSD code, Apple CoreFoundation

Connections: Sqlite · Openbsd · C Programming · Secure Coding · Memory Management

Source: https://github.com/btrask/stronglink/blob/master/SUBSTANCE.md