114-java-secure-coding

Java Secure coding guidelines

This document provides essential Java secure coding guidelines, focusing on five key areas: validating all untrusted inputs to prevent attacks like injection and path traversal; protecting against injection attacks (e.g., SQL injection) by using parameterized queries or prepared statements; minimizing the attack surface by adhering to the principle of least privilege and reducing exposure; employing strong, current cryptographic algorithms for hashing, encryption, and digital signatures while avoiding deprecated ones; and handling exceptions securely by avoiding the exposure of sensitive information in error messages to users and logging detailed, non-sensitive diagnostic information for developers.

Implementing These Principles

These guidelines are built upon the following core principles:

1. Comprehensive Input Validation: Treat all external input as untrusted. Rigorously validate and sanitize data for type, length, format, and range before processing to prevent common vulnerabilities like injection attacks, path traversal, and buffer overflows.
2. Defense Against Injection: Actively protect against all forms of injection attacks (e.g., SQL, OS Command, LDAP, XPath). Primarily achieve this by using safe APIs like parameterized queries (e.g., PreparedStatement in JDBC) or dedicated libraries that correctly handle data escaping, and by never directly concatenating untrusted input into executable commands or queries.
3. Attack Surface Minimization: Adhere to the principle of least privilege for users, processes, and code. Reduce the exposure of system components by running with minimal necessary permissions, exposing only essential functionalities and network ports, and regularly reviewing and removing unused features, libraries, and accounts.
4. Strong Cryptographic Practices: Employ current, robust, and industry-standard cryptographic algorithms and libraries for all sensitive operations, including hashing (especially for passwords), encryption, and digital signatures. Avoid deprecated or weak algorithms. Ensure cryptographic keys are generated securely, stored safely, and managed properly throughout their lifecycle.
5. Secure Exception Handling: Manage exceptions in a way that does not expose sensitive information to users or attackers. Log detailed, non-sensitive diagnostic information for developers to aid in debugging, but provide generic, non-revealing error messages to clients. Avoid direct exposure of stack traces or internal system details in error outputs.