Merge pull request #256 from alxndrv/add-mcookie

Implement `mcookie`

Cargo.lock

@@ -88,6 +88,15 @@ version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8f68f53c83ab957f72c32642f3868eec03eb974d1fb82e453128456482613d36"
 
+[[package]]
+name = "block-buffer"
+version = "0.10.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "bumpalo"
 version = "3.17.0"
@@ -240,6 +249,16 @@ version = "0.8.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
 
+[[package]]
+name = "crypto-common"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
+dependencies = [
+ "generic-array",
+ "typenum",
+]
+
 [[package]]
 name = "deranged"
 version = "0.3.11"
@@ -255,6 +274,16 @@ version = "0.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "56254986775e3233ffa9c4d7d3faaf6d36a2c09d30b20687e9f88bc8bafc16c8"
 
+[[package]]
+name = "digest"
+version = "0.10.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
 [[package]]
 name = "dns-lookup"
 version = "2.0.4"
@@ -295,6 +324,16 @@ version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "37909eebbb50d72f9059c3b6d82c0463f2ff062c9e95845c43a6c9c0355411be"
 
+[[package]]
+name = "generic-array"
+version = "0.14.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85649ca51fd72272d7821adaf274ad91c288277713d9c18820d8499a7ff69e9a"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.3.1"
@@ -404,6 +443,16 @@ version = "0.4.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "04cbf5b083de1c7e0222a7a51dbfdba1cbe1c6ab0b15e29fff3f6c077fd9cd9f"
 
+[[package]]
+name = "md-5"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d89e7ee0cfbedfc4da3340218492196241d89eefb6dab27de5df917a6d2e78cf"
+dependencies = [
+ "cfg-if",
+ "digest",
+]
+
 [[package]]
 name = "memchr"
 version = "2.7.4"
@@ -916,6 +965,12 @@ dependencies = [
  "time-core",
 ]
 
+[[package]]
+name = "typenum"
+version = "1.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1dccffe3ce07af9386bfd29e80c0ab1a8205a2fc34e4bcd40364df902cfa8f3f"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.16"
@@ -975,6 +1030,7 @@ dependencies = [
  "uu_lscpu",
  "uu_lslocks",
  "uu_lsmem",
+ "uu_mcookie",
  "uu_mesg",
  "uu_mountpoint",
  "uu_renice",
@@ -1068,6 +1124,16 @@ dependencies = [
  "uucore",
 ]
 
+[[package]]
+name = "uu_mcookie"
+version = "0.0.1"
+dependencies = [
+ "clap",
+ "md-5",
+ "rand 0.9.0",
+ "uucore",
+]
+
 [[package]]
 name = "uu_mesg"
 version = "0.0.1"
@@ -1149,6 +1215,12 @@ version = "0.0.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0bb6d972f580f8223cb7052d8580aea2b7061e368cf476de32ea9457b19459ed"
 
+[[package]]
+name = "version_check"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
+
 [[package]]
 name = "wasi"
 version = "0.13.3+wasi-0.2.2"

Cargo.toml

@@ -34,6 +34,7 @@ feat_common_core = [
   "lscpu",
   "lslocks",
   "lsmem",
+  "mcookie",
   "mesg",
   "mountpoint",
   "renice",
@@ -48,6 +49,7 @@ clap_mangen = "0.2"
 dns-lookup = "2.0.4"
 libc = "0.2.152"
 linux-raw-sys = { version = "0.9.0", features = ["ioctl"] }
+md-5 = "0.10.6"
 nix = { version = "0.29", default-features = false }
 phf = "0.11.2"
 phf_codegen = "0.11.2"
@@ -81,6 +83,7 @@ last = { optional = true, version = "0.0.1", package = "uu_last", path = "src/uu
 lscpu = { optional = true, version = "0.0.1", package = "uu_lscpu", path = "src/uu/lscpu" }
 lslocks = { optional = true, version = "0.0.1", package = "uu_lslocks", path = "src/uu/lslocks" }
 lsmem = { optional = true, version = "0.0.1", package = "uu_lsmem", path = "src/uu/lsmem" }
+mcookie = { optional = true, version = "0.0.1", package = "uu_mcookie", path = "src/uu/mcookie" }
 mesg = { optional = true, version = "0.0.1", package = "uu_mesg", path = "src/uu/mesg" }
 mountpoint = { optional = true, version = "0.0.1", package = "uu_mountpoint", path = "src/uu/mountpoint" }
 renice = { optional = true, version = "0.0.1", package = "uu_renice", path = "src/uu/renice" }

src/uu/mcookie/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "uu_mcookie"
+version = "0.0.1"
+edition = "2021"
+
+[lib]
+path = "src/mcookie.rs"
+
+[[bin]]
+name = "mcookie"
+path = "src/main.rs"
+
+[dependencies]
+uucore = { workspace = true }
+clap = { workspace = true }
+md-5 = { workspace = true }
+rand = { workspace = true }

src/uu/mcookie/mcookie.md

@@ -0,0 +1,7 @@
+# mcookie
+
+```
+mcookie [OPTION]...
+```
+
+Generate magic cookies for xauth.

src/uu/mcookie/src/main.rs

@@ -0,0 +1 @@
+uucore::bin!(uu_mcookie);

src/uu/mcookie/src/mcookie.rs

@@ -0,0 +1,111 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+use std::{fs::File, io::Read};
+
+use clap::{crate_version, Arg, ArgAction, Command};
+use md5::{Digest, Md5};
+use rand::RngCore;
+use uucore::{error::UResult, format_usage, help_about, help_usage};
+
+mod options {
+    pub const FILE: &str = "file";
+    pub const MAX_SIZE: &str = "max-size";
+    pub const VERBOSE: &str = "verbose";
+}
+
+const ABOUT: &str = help_about!("mcookie.md");
+const USAGE: &str = help_usage!("mcookie.md");
+
+#[uucore::main]
+pub fn uumain(args: impl uucore::Args) -> UResult<()> {
+    let matches: clap::ArgMatches = uu_app().try_get_matches_from(args)?;
+
+    let verbose = matches.get_flag(options::VERBOSE);
+
+    let seed_files: Vec<&str> = matches
+        .get_many::<String>(options::FILE)
+        .unwrap_or_default()
+        .map(|v| v.as_str())
+        .collect();
+
+    // TODO: Parse max size from human-readable strings (KiB, MiB, GiB etc.)
+    let max_size = matches
+        .get_one::<String>(options::MAX_SIZE)
+        .map(|v| v.parse::<u64>().expect("Failed to parse max-size value"));
+
+    let mut hasher = Md5::new();
+
+    for file in seed_files {
+        let mut f = File::open(file)?;
+        let mut buffer: Vec<u8> = Vec::new();
+
+        if let Some(max_bytes) = &max_size {
+            let mut handle = f.take(*max_bytes);
+            handle.read_to_end(&mut buffer)?;
+        } else {
+            f.read_to_end(&mut buffer)?;
+        }
+
+        if verbose {
+            eprintln!("Got {} bytes from {}", buffer.len(), file);
+        }
+
+        hasher.update(&buffer);
+    }
+
+    const RANDOM_BYTES: usize = 128;
+    let mut rng = rand::rng();
+    let mut rand_bytes = [0u8; RANDOM_BYTES];
+    rng.fill_bytes(&mut rand_bytes);
+
+    hasher.update(rand_bytes);
+
+    if verbose {
+        eprintln!("Got {} bytes from randomness source", RANDOM_BYTES);
+    }
+
+    let result = hasher.finalize();
+    let output = result
+        .iter()
+        .map(|byte| format!("{:02x}", byte))
+        .collect::<Vec<_>>()
+        .join("");
+
+    println!("{}", output);
+
+    Ok(())
+}
+
+pub fn uu_app() -> Command {
+    Command::new(uucore::util_name())
+        .version(crate_version!())
+        .about(ABOUT)
+        .override_usage(format_usage(USAGE))
+        .infer_long_args(true)
+        .arg(
+            Arg::new(options::FILE)
+                .short('f')
+                .long("file")
+                .value_name("file")
+                .action(ArgAction::Append)
+                .help("use file as a cookie seed"),
+        )
+        .arg(
+            Arg::new(options::MAX_SIZE)
+                .short('m')
+                .long("max-size")
+                .value_name("num")
+                .action(ArgAction::Set)
+                .help("limit how much is read from seed files"),
+        )
+        .arg(
+            Arg::new(options::VERBOSE)
+                .short('v')
+                .long("verbose")
+                .action(ArgAction::SetTrue)
+                .help("explain what is being done"),
+        )
+}

tests/by-util/test_mcookie.rs

@@ -0,0 +1,65 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+use std::io::Write;
+
+use tempfile::{NamedTempFile, TempDir};
+
+use crate::common::util::TestScenario;
+
+#[test]
+fn test_invalid_arg() {
+    new_ucmd!().arg("--definitely-invalid").fails().code_is(1);
+}
+
+#[test]
+fn test_basic_usage() {
+    let res = new_ucmd!().succeeds();
+
+    let stdout = res.no_stderr().stdout_str();
+
+    // Expect 32 hex characters for the MD5 hash (after trimming the newline)
+    assert_eq!(stdout.trim_end().len(), 32);
+    assert!(stdout.trim_end().chars().all(|c| c.is_ascii_hexdigit()));
+}
+
+#[test]
+fn test_verbose() {
+    let res = new_ucmd!().arg("--verbose").succeeds();
+    res.stderr_contains("Got 128 bytes from randomness source");
+}
+
+#[test]
+fn test_seed_files_and_max_size() {
+    let mut file1 = NamedTempFile::new().unwrap();
+    const CONTENT1: &str = "Some seed data";
+    file1.write_all(CONTENT1.as_bytes()).unwrap();
+
+    let mut file2 = NamedTempFile::new().unwrap();
+    const CONTENT2: [u8; 2048] = [1; 2048];
+    file2.write_all(&CONTENT2).unwrap();
+
+    let res = new_ucmd!()
+        .arg("--verbose")
+        .arg("-f")
+        .arg(file1.path())
+        .arg("-f")
+        .arg(file2.path())
+        .arg("-m")
+        .arg("1337")
+        .succeeds();
+
+    res.stderr_contains(format!(
+        "Got {} bytes from {}",
+        CONTENT1.len(),
+        file1.path().to_str().unwrap()
+    ));
+
+    // Ensure we only read up to the limit of bytes, despite the file being bigger
+    res.stderr_contains(format!(
+        "Got 1337 bytes from {}",
+        file2.path().to_str().unwrap()
+    ));
+}

tests/tests.rs

@@ -56,3 +56,7 @@ mod test_dmesg;
 #[cfg(feature = "fsfreeze")]
 #[path = "by-util/test_fsfreeze.rs"]
 mod test_fsfreeze;
+
+#[cfg(feature = "mcookie")]
+#[path = "by-util/test_mcookie.rs"]
+mod test_mcookie;