refactor: replace with_context calls with context calls

- set meaningful value names for options
- add backticks around CLI options in user-facing messages

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "fingerprunk"
-version = "0.1.0"
+version = "0.3.0"
 authors = ["Niklas Elsbrock <mail@nelsbrock.de>"]
 edition = "2024"
 description = "CLI tool for brute-forcing OpenPGP keys with cool fingerprints"
@@ -10,10 +10,10 @@ keywords = ["fingerprint", "openpgp", "bruteforce"]
 categories = ["command-line-utilities"]
 
 [dependencies]
-anyhow = "1.0.100"
+anyhow = "1.0.102"
-clap = { version = "4.5.50", features = ["derive"] }
+clap = { version = "4.6.1", features = ["derive"] }
-fancy-regex = "0.16.2"
+ctrlc = "3.5.2"
+fancy-regex = "0.18.0"
 num-integer = "0.1.46"
-num_cpus = "1.17.0"
+rpassword = "7.5.2"
-rpassword = "7.4.0"
+sequoia-openpgp = "2.2.0"
-sequoia-openpgp = "2.0.0"

README.md

@@ -13,15 +13,16 @@ cargo install fingerprunk
 
 ## Usage
 
-Let's say you want to find keys whose fingerprints begin with `C0FFEE` and store them `secret.asc`.
+Let's say you want to find keys whose fingerprints begin with `C0FFEE` and store them
-The regex for this is `^C0FFEE`. Now, simply use the following command to start the search:
+at `secret.asc`. The regex for this is `^C0FFEE`. Now, simply use the following command to start
+the search:
 
 ```sh
-fingerprunk -r '^C0FFEE' >> secret.asc
+fingerprunk -r '^C0FFEE' -u "Your Name <your.email@example.org>" >> secret.asc
 ```
 
 Fingerprunk will now generate many keys and write out all keys with matching fingerprints to
-standard output (here: `secret.asc`).
+standard output (here: `secret.asc`), adding the provided user ID.
 
 If you want Fingerprunk to output password-encrypted keys use the `-p` flag and you will be prompted
 for a password.
@@ -49,25 +50,25 @@ Also see <https://en.wikipedia.org/wiki/Hexspeak> for some further examples of "
 
 ### How long does it take?
 
-On my machine with an AMD Ryzen 7 5800X Processor, Fingerprunk is able to generate and check about
+On my machine with an AMD Ryzen 7 5800X processor, Fingerprunk is able to generate and check about
-43300 keys per second. This means that for finding a fingerprint with a string of *n* specific
+43500 keys per second. This means that for finding a fingerprint with a string of *n* specific
 hexadecimal digits at a specific place, I could expect the following runtimes until finding the
 first key:
 
-| *n* |  expected tries | expected time |
+| *n* |         estimate tries | estimate time |
-| --: | --------------: | ------------: |
+| --: | ---------------------: | ------------: |
-| *n* |             16ⁿ |  43300s / 16ⁿ |
+|   1 |              16 =  16¹ |    < 0.1 secs |
-|   2 |             256 |   0.0059 secs |
+|   2 |             256 =  16² |    < 0.1 secs |
-|   3 |            4096 |   0.0946 secs |
+|   3 |            4096 =  16³ |      0.1 secs |
-|   4 |           65536 |      1.5 secs |
+|   4 |           65536 =  16⁴ |      1.5 secs |
-|   5 |         1028576 |       24 secs |
+|   5 |         1048576 =  16⁵ |       24 secs |
-|   6 |        16777216 |      6.5 mins |
+|   6 |        16777216 =  16⁶ |        6 mins |
-|   7 |       268435456 |      103 mins |
+|   7 |       268435456 =  16⁷ |       2 hours |
-|   8 |      4294967296 |      27 hours |
+|   8 |      4294967296 =  16⁸ |        1 days |
-|   9 |     68719476736 |       18 days |
+|   9 |     68719476736 =  16⁹ |       18 days |
-|  10 |   1099511627776 |      293 days |
+|  10 |   1099511627776 = 16¹⁰ |      293 days |
-|  11 |  17592186044416 |      13 years |
+|  11 |  17592186044416 = 16¹¹ |      13 years |
-|  12 | 281474976710656 |     206 years |
+|  12 | 281474976710656 = 16¹² |     205 years |
 
-As you can see, anything above 8 or 9 fixed digits is pretty much unfeasible, at least with
+As you can see, anything above 10 fixed digits is pretty much unfeasible, at least with a normal
-a normal personal computer.
+personal computer.

src/lib.rs

@@ -2,41 +2,53 @@
 
 use std::{
     fmt::{self, Write},
-    io::{self},
+    io,
+    num::NonZero,
     sync::{
-        atomic::{AtomicU64, Ordering},
+        atomic::{AtomicBool, AtomicU64, Ordering},
-        mpsc::{self, Receiver},
+        mpsc,
     },
     thread,
-    time::{Duration, Instant},
+    time::{Duration, Instant, SystemTime},
 };
 
 use fancy_regex::Regex;
 use num_integer::Integer;
 use sequoia_openpgp::{
-    Cert, Packet,
+    Cert, Packet, armor,
     crypto::Password,
     packet::{
-        Key,
+        Key, UserID,
         key::{Key4, PrimaryRole, SecretParts},
         prelude::SignatureBuilder,
     },
     serialize::Serialize,
-    types::{HashAlgorithm, SignatureType, SymmetricAlgorithm},
+    types::{Curve, HashAlgorithm, SignatureType, SymmetricAlgorithm},
 };
 
 type SecretKey = Key<SecretParts, PrimaryRole>;
 
+#[allow(clippy::large_enum_variant)]
+enum Message {
+    Key(SecretKey),
+    Stop,
+}
+
 #[derive(Clone, Debug)]
 pub struct Config {
     pub regex: Regex,
     pub status_enabled: bool,
+    pub stop_after: Option<NonZero<u64>>,
     pub password: Option<Password>,
+    pub userids: Vec<UserID>,
+    pub workers: NonZero<usize>,
 }
 
 #[derive(Debug)]
 pub struct Fingerprunk {
     config: Config,
+    started_instant: Instant,
+    stop: AtomicBool,
     counter_tried: AtomicU64,
     counter_found: AtomicU64,
 }
@@ -52,54 +64,86 @@ impl Fingerprunk {
     pub fn new_from_config(config: Config) -> Self {
         Self {
             config,
+            started_instant: Instant::now(),
+            stop: AtomicBool::new(false),
             counter_tried: AtomicU64::new(0),
             counter_found: AtomicU64::new(0),
         }
     }
 
-    pub fn run(self) {
+    pub fn run(mut self) -> anyhow::Result<()> {
-        let (tx, rx) = mpsc::channel();
+        self.started_instant = Instant::now();
+
+        let (sender, receiver) = mpsc::sync_channel(16);
+
+        {
+            let sender = sender.clone();
+            ctrlc::set_handler(move || {
+                let _ = sender.send(Message::Stop);
+            })?;
+        }
 
         thread::scope(|scope| {
-            const THREAD_SPAWN_EXPECT_MSG: &str = "should be able to spawn thread";
+            let status_displayer = if self.config.status_enabled {
-
+                Some(
-            let ref_self = &self;
-
-            if self.config.status_enabled {
                     thread::Builder::new()
                         .name("status_displayer".to_string())
-                    .spawn_scoped(scope, move || ref_self.status_displayer_thread())
+                        .spawn_scoped(scope, || self.status_displayer_thread())?,
-                    .expect(THREAD_SPAWN_EXPECT_MSG);
+                )
-            }
+            } else {
-
+                None
-            for num in 0..num_cpus::get() {
+            };
-                let tx = tx.clone();
 
+            for num in 0..self.config.workers.get() {
                 thread::Builder::new()
                     .name(format!("worker-{num:03}"))
-                    .spawn_scoped(scope, move || ref_self.worker_thread(tx))
+                    .spawn_scoped(scope, || self.worker_thread(&sender))?;
-                    .expect(THREAD_SPAWN_EXPECT_MSG);
             }
 
-            thread::Builder::new()
+            let mut stdout = io::stdout().lock();
-                .name("finalizer".to_string())
+
-                .spawn_scoped(scope, move || ref_self.finalizer_thread(rx))
+            // Receive and process messages from the workers and the ctrl-c handler
-                .expect(THREAD_SPAWN_EXPECT_MSG);
+            for message in receiver {
-        });
+                match message {
+                    Message::Key(key) => {
+                        let cert = self.key_to_cert(key)?;
+                        self.serialize_cert(&cert, &mut stdout)?;
+
+                        // Increase "found" counter and stop if enough matches have been found
+                        let prev = self.counter_found.fetch_add(1, Ordering::Relaxed);
+                        if self.config.stop_after.is_some_and(|s| prev + 1 == s.get()) {
+                            break;
+                        }
+                    }
+                    Message::Stop => break,
+                }
             }
 
-    fn worker_thread(&self, matches_tx: mpsc::Sender<SecretKey>) {
+            // Ask all other threads to stop
+            self.stop.store(true, Ordering::Relaxed);
+
+            // Unpark the status displayer thread, if existant
+            if let Some(status_displayer) = status_displayer {
+                status_displayer.thread().unpark();
+            }
+
+            Ok(())
+        })
+    }
+
+    fn worker_thread(&self, sender: &mpsc::SyncSender<Message>) {
         let mut fingerprint_hex = String::with_capacity(20 * 2);
 
-        loop {
+        while !self.stop.load(Ordering::Relaxed) {
-            let key = Key4::generate_ed25519().expect("should be able to generate key");
+            let key =
+                Key4::generate_ecc(true, Curve::Ed25519).expect("should be able to generate key");
             fingerprint_hex.clear();
             write!(fingerprint_hex, "{:X}", key.fingerprint())
                 .expect("should write into string without error");
             if self.check_fingerprint(&fingerprint_hex) {
-                matches_tx
+                // The channel might already be closed here if we're stopping.
-                    .send(Key::V4(key))
+                // That is fine, so we just ignore the error.
-                    .expect("should be able to send key");
+                let _ = sender.send(Message::Key(Key::V4(key)));
             }
             self.counter_tried.fetch_add(1, Ordering::Relaxed);
         }
@@ -113,51 +157,88 @@ impl Fingerprunk {
             .expect("should check regex without error")
     }
 
-    fn finalizer_thread(&self, matches_rx: Receiver<SecretKey>) {
+    fn key_to_cert(&self, mut key: SecretKey) -> anyhow::Result<Cert> {
-        let mut stdout = io::stdout().lock();
+        let creation_time = SystemTime::now();
-
-        for key in matches_rx {
-            let result = self
-                .key_to_cert(&key)
-                .and_then(|cert| cert.as_tsk().armored().serialize(&mut stdout));
-
-            if let Err(err) = result {
-                eprintln!("Error: {err}");
-            } else {
-                self.counter_found.fetch_add(1, Ordering::Relaxed);
-            }
-        }
-    }
-
-    fn key_to_cert(&self, key: &SecretKey) -> anyhow::Result<Cert> {
-        let sig = SignatureBuilder::new(SignatureType::DirectKey)
-            .set_hash_algo(HashAlgorithm::SHA512)
-            .set_preferred_hash_algorithms(vec![HashAlgorithm::SHA512, HashAlgorithm::SHA256])?
-            .set_preferred_symmetric_algorithms(vec![
-                SymmetricAlgorithm::AES256,
-                SymmetricAlgorithm::AES128,
-            ])?;
 
         let mut signer = key
             .clone()
             .into_keypair()
             .expect("key should have a secret");
-        let sig = sig.sign_direct_key(&mut signer, key.parts_as_public())?;
 
-        let secret_key_packet = Packet::SecretKey({
+        // Sign keypair
-            let mut key = key.clone();
+        let key_sig = create_sig_builder(SignatureType::DirectKey, creation_time)?
+            .sign_direct_key(&mut signer, key.parts_as_public())?;
+
+        // Create certificate
+        let mut cert = Cert::try_from(Packet::SecretKey({
             if let Some(ref password) = self.config.password {
                 let (k, mut secret) = key.take_secret();
                 secret.encrypt_in_place(&k, password)?;
                 key = k.add_secret(secret).0;
             }
             key
-        });
+        }))?;
 
-        Cert::try_from(vec![secret_key_packet, Packet::from(sig)])
+        let mut packets = vec![Packet::from(key_sig)];
+
+        // Sign user IDs
+        let mut next_is_primary = true;
+        for user_id in self.config.userids.iter().cloned() {
+            let mut sig_builder =
+                create_sig_builder(SignatureType::PositiveCertification, creation_time)?;
+            if next_is_primary {
+                sig_builder = sig_builder.set_primary_userid(true)?;
+                next_is_primary = false;
+            }
+            let sig = user_id.bind(&mut signer, &cert, sig_builder)?;
+
+            packets.push(user_id.into());
+            packets.push(sig.into());
+        }
+
+        cert = cert.insert_packets(packets)?.0;
+        Ok(cert)
+    }
+
+    fn serialize_cert(&self, cert: &Cert, to: impl io::Write) -> anyhow::Result<()> {
+        let mut comments = cert.armor_headers();
+        comments.push(format!(
+            "Generated with Fingerprunk. Regex: {}",
+            self.config.regex
+        ));
+
+        let headers: Vec<_> = comments
+            .into_iter()
+            .map(|s| ("Comment".to_string(), s))
+            .collect();
+
+        let mut writer = armor::Writer::with_headers(to, armor::Kind::SecretKey, headers)?;
+
+        // Set the profile to RFC4880 because we generate v4 keys.
+        writer.set_profile(sequoia_openpgp::Profile::RFC4880)?;
+
+        cert.serialize(&mut writer)?;
+        writer.finalize()?;
+
+        Ok(())
     }
 
     fn status_displayer_thread(&self) {
+        const UPDATE_INTERVAL: Duration = Duration::from_millis(250);
+
+        eprint!("\n\n\n\n\n");
+
+        while !self.stop.load(Ordering::Relaxed) {
+            self.print_status();
+            // We are parking the thread instead of sleeping so we can unpark it when we want to
+            // stop the program.
+            thread::park_timeout(UPDATE_INTERVAL);
+        }
+
+        self.print_status();
+    }
+
+    fn print_status(&self) {
         struct DurationDhms(Duration);
 
         impl fmt::Display for DurationDhms {
@@ -171,15 +252,9 @@ impl Fingerprunk {
             }
         }
 
-        const UPDATE_INTERVAL: Duration = Duration::from_millis(250);
         const FORMAT_WIDTH: usize = 12;
 
-        let start = Instant::now();
+        let duration = DurationDhms(self.started_instant.elapsed());
-
-        eprint!("\n\n\n\n\n");
-
-        loop {
-            let duration = DurationDhms(start.elapsed());
         let keys = self.counter_tried.load(Ordering::Relaxed);
         let keys_per_sec = keys as f64 / duration.0.as_secs_f64();
         let found = self.counter_found.load(Ordering::Relaxed);
@@ -192,7 +267,19 @@ impl Fingerprunk {
                 Found: {found: >w$} keys\n",
             w = FORMAT_WIDTH
         );
-            thread::sleep(UPDATE_INTERVAL);
     }
 }
+
+fn create_sig_builder(
+    typ: SignatureType,
+    creation_time: SystemTime,
+) -> Result<SignatureBuilder, anyhow::Error> {
+    SignatureBuilder::new(typ)
+        .set_signature_creation_time(creation_time)?
+        .set_hash_algo(HashAlgorithm::SHA512)
+        .set_preferred_hash_algorithms(vec![HashAlgorithm::SHA512, HashAlgorithm::SHA256])?
+        .set_preferred_symmetric_algorithms(vec![
+            SymmetricAlgorithm::AES256,
+            SymmetricAlgorithm::AES128,
+        ])
 }

src/main.rs

@@ -1,9 +1,13 @@
-use std::io::{self, IsTerminal};
+use std::{
+    io::{self, IsTerminal},
+    num::NonZero,
+};
 
-use anyhow::{Context as AnyhowContext, anyhow};
+use anyhow::{Context, anyhow};
 use clap::{ArgAction, Parser, ValueEnum};
 use fancy_regex::Regex;
 use fingerprunk::Fingerprunk;
+use sequoia_openpgp::packet::UserID;
 
 #[derive(Parser, Debug)]
 #[command(version, about, long_about = None)]
@@ -26,12 +30,33 @@ struct Args {
     #[arg(long, value_enum, default_value_t)]
     status: StatusEnabled,
 
-    /// Prompt for a password and use it to encrypt found keys.
+    /// Stop once the specified number of matching keys has been found.
+    #[arg(long, value_name = "NUM")]
+    stop_after: Option<NonZero<u64>>,
+
+    /// Prompt for a password and use it to encrypt matching keys.
     ///
     /// By default, found keys are printed to stdout unencrypted. Use this if you actually plan to
     /// use generated keys.
     #[arg(short, long, action = ArgAction::SetTrue)]
     password: bool,
+
+    /// Add the given user ID to matching keys.
+    #[arg(short, long = "userid")]
+    userid: Vec<UserID>,
+
+    /// Explicitly do not add user IDs to matching keys.
+    ///
+    /// Disables the warning about importing keys without user IDs into GnuPG.
+    #[arg(long, conflicts_with = "userid", action = ArgAction::SetTrue)]
+    no_userid: bool,
+
+    /// Use the specified amount of worker threads.
+    ///
+    /// If not specified, the amount of worker threads will be set to the amount of the machine's
+    /// available parallelism.
+    #[arg(long, value_name = "NUM")]
+    workers: Option<NonZero<usize>>,
 }
 
 #[derive(ValueEnum, Clone, Copy, Debug, Default)]
@@ -55,16 +80,33 @@ impl StatusEnabled {
 fn main() -> anyhow::Result<()> {
     let args = Args::parse();
 
+    let workers = match args.workers {
+        Some(workers) => workers,
+        None => std::thread::available_parallelism().context(
+            "unable to determine available parallelism, \
+            use `--workers <NUM>` to specify amount of worker threads",
+        )?,
+    };
+
+    if !args.no_userid && args.userid.is_empty() {
+        eprintln!(
+            "WARNING: No user ID was provided.\n\
+            You may experience problems importing generated keys into GnuPG.\n\
+            Use `--userid <USERID>` to add a user ID.\n"
+        );
+    }
+
     let password = if args.password {
         let password = rpassword::prompt_password(
             "Enter password for encrypting found keys (leave empty for no encryption): ",
         )
-        .with_context(|| "Failed to prompt password")?;
+        .context("Failed to prompt password")?;
+
         if password.is_empty() {
             None
         } else {
             let password_retype = rpassword::prompt_password("Retype password: ")
-                .with_context(|| "Failed to prompt password retype")?;
+                .context("Failed to prompt password retype")?;
             if password_retype == password {
                 Some(password.into())
             } else {
@@ -78,10 +120,11 @@ fn main() -> anyhow::Result<()> {
     let config = fingerprunk::Config {
         regex: args.regex,
         status_enabled: args.status.evaluate(),
+        stop_after: args.stop_after,
         password,
+        userids: args.userid,
+        workers,
     };
 
-    Fingerprunk::new_from_config(config).run();
+    Fingerprunk::new_from_config(config).run()
-
-    Ok(())
 }