Function decrypt 

pub fn decrypt<R, W>(
    input: R,
    output: W,
    password: &PasswordString,
) -> Result<(), AescryptError>
where
    R: Read,
    W: Write,

Decrypt an Aescrypt file (v0–v3) — zero secret exposure, maximum security

Thread Safety

This function is thread-safe and can be called concurrently from multiple threads. All operations are pure (no shared mutable state), making it safe to:

• Spawn in threads for parallel processing
• Use with async runtimes (spawn_blocking)
• Implement cancellation by wrapping in a thread and joining/detaching as needed

Performance

For large files, this operation may take significant time. In release mode, expect:

• ~158 MiB/s throughput for decryption
• Processing time scales linearly with file size

Users requiring cancellation should spawn this function in a thread and implement their own cancellation mechanism (e.g., using channels or thread handles).

Example: Threaded Usage

use aescrypt_rs::{decrypt, PasswordString};
use std::io::Cursor;
use std::thread;

let password = PasswordString::new("secret".to_string());
let encrypted = b"encrypted data...";

// Spawn decryption in a thread
let handle = thread::spawn(move || {
    let mut plaintext = Vec::new();
    decrypt(Cursor::new(encrypted), &mut plaintext, &password)
});

// Can wait for completion or implement cancellation
let result = handle.join().unwrap();