Crate perl_dap_eval 

Safe Expression Evaluation Validation for Perl DAP

This crate provides security validation for expressions evaluated during Perl debugging. It detects and blocks potentially dangerous operations that could mutate state, execute arbitrary code, or perform I/O operations during debug evaluation.

Features

• Operation Detection: Detects dangerous Perl operations (eval, system, exec, etc.)
• Mutation Detection: Detects assignment and increment/decrement operators
• Shell Execution Detection: Blocks backticks and qx() for shell execution
• Context-Aware: Avoids false positives for sigil-prefixed identifiers ($print, @say)

Example

use perl_dap_eval::{SafeEvaluator, ValidationResult};

let evaluator = SafeEvaluator::new();

// Safe expressions pass validation
assert!(evaluator.validate("$x + $y").is_ok());

// Dangerous operations are blocked
let result = evaluator.validate("system('rm -rf /')");
assert!(result.is_err());

Security Model

The safe evaluator blocks the following categories of operations:

• Code Execution: eval, require, do (file)
• Process Control: system, exec, fork, exit, kill, etc.
• I/O Operations: print, say, open, close, etc.
• Filesystem: mkdir, rmdir, unlink, chmod, etc.
• Network: socket, connect, bind, etc.
• Tie Mechanism: tie/untie (can execute arbitrary code)
• Mutation: Assignment operators, ++/–, regex mutation (s///)

Structs

SafeEvaluator

Safe expression evaluator

Enums

ValidationError

Error type for unsafe expression detection

Constants

DANGEROUS_OPERATIONS

List of dangerous Perl operations that can mutate state, perform I/O, or execute code

Type Aliases

ValidationResult

Result type for expression validation