stage

problems/p5/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "p5"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+common = { path = "../../common/" }
+hex = "0.4.3"
+anyhow = "1.0.98"

problems/p5/src/main.rs

@@ -0,0 +1,26 @@
+use anyhow::{Result, anyhow};
+
+fn xor_with_key(input: &[u8], key: &[u8]) -> Result<Vec<u8>> {
+    if key.is_empty() {
+        return Err(anyhow!("empty key"));
+    }
+    Ok(input
+        .iter()
+        .zip(key.iter().cycle())
+        .map(|(&a, &b)| a ^ b)
+        .collect())
+}
+
+fn main() -> Result<()> {
+    let plaintexts = r#"
+Burning 'em, if you ain't quick and nimble I go crazy when I hear a cymbal
+"#;
+    let key = b"ICE";
+    for plaintext in plaintexts.lines() {
+        let plaintext_bytes = plaintext.as_bytes();
+        let cipher = xor_with_key(plaintext_bytes, key)?;
+        println!("{}", hex::encode(cipher));
+    }
+    Ok(())
+}
+