add --userid option

README.md

@@ -18,11 +18,11 @@ at `secret.asc`. The regex for this is `^C0FFEE`. Now, simply use the following
 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.

src/lib.rs

@@ -9,7 +9,7 @@ use std::{
         mpsc,
     },
     thread,
-    time::{Duration, Instant},
+    time::{Duration, Instant, SystemTime},
 };
 
 use fancy_regex::Regex;
@@ -18,7 +18,7 @@ use sequoia_openpgp::{
     Cert, Packet, armor,
     crypto::Password,
     packet::{
-        Key,
+        Key, UserID,
         key::{Key4, PrimaryRole, SecretParts},
         prelude::SignatureBuilder,
     },
@@ -40,6 +40,7 @@ pub struct Config {
     pub status_enabled: bool,
     pub stop_after: Option<NonZeroU64>,
     pub password: Option<Password>,
+    pub userids: Vec<UserID>,
 }
 
 #[derive(Debug)]
@@ -160,21 +161,19 @@ impl Fingerprunk {
     }
 
     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 creation_time = SystemTime::now();
 
         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 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({
             let mut key = key.clone();
             if let Some(ref password) = self.config.password {
                 let (k, mut secret) = key.take_secret();
@@ -182,9 +181,27 @@ impl Fingerprunk {
                 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<()> {
@@ -256,3 +273,17 @@ impl Fingerprunk {
         );
     }
 }
+
+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

@@ -7,6 +7,7 @@ use anyhow::{Context as AnyhowContext, 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)]
@@ -33,12 +34,22 @@ struct Args {
     #[arg(long)]
     stop_after: Option<NonZeroU64>,
 
-    /// Prompt for a password and use it to encrypt found keys.
+    /// 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,
 }
 
 #[derive(ValueEnum, Clone, Copy, Debug, Default)]
@@ -62,6 +73,14 @@ impl StatusEnabled {
 fn main() -> anyhow::Result<()> {
     let args = Args::parse();
 
+    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 the --userid option 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): ",
@@ -87,6 +106,7 @@ fn main() -> anyhow::Result<()> {
         status_enabled: args.status.evaluate(),
         stop_after: args.stop_after,
         password,
+        userids: args.userid,
     };
 
     Fingerprunk::new_from_config(config).run()?;