Use cert designators for the certifier in sq pki vouch certify.

- See #207.

src/cli/pki/vouch/certify.rs

@@ -1,22 +1,16 @@
 //! Command-line parser for `sq pki vouch certify`.
 
-use clap::ArgGroup;
 use clap::Parser;
 
-use sequoia_openpgp as openpgp;
-use openpgp::KeyHandle;
-
 use crate::cli::THIRD_PARTY_CERTIFICATION_VALIDITY_DURATION;
 use crate::cli::THIRD_PARTY_CERTIFICATION_VALIDITY_IN_YEARS;
 
-use crate::cli::types::CertDesignators;
 use crate::cli::types::ClapData;
 use crate::cli::types::Expiration;
-use crate::cli::types::FileOrStdin;
 use crate::cli::types::FileOrStdout;
 use crate::cli::types::TrustAmount;
 use crate::cli::types::UserIDDesignators;
-use crate::cli::types::cert_designator;
+use crate::cli::types::cert_designator::{self, *};
 use crate::cli::types::userid_designator;
 
 use crate::cli::examples::*;
@@ -87,21 +81,12 @@ reference time.
     ),
     after_help = CERTIFY_EXAMPLES,
 )]
-#[clap(group(ArgGroup::new("certifier_input").args(&["certifier_file", "certifier"]).required(true)))]
 pub struct Command {
-    #[clap(
-        long,
-        value_name = "KEY",
-        help = "Create the certification using KEY.",
-    )]
-    pub certifier: Option<KeyHandle>,
-    #[clap(
-        long,
-        value_name = "KEY-FILE",
-        required = true,
-        help = "Create the certification using KEY-FILE.",
-    )]
-    pub certifier_file: Option<FileOrStdin>,
+    #[command(flatten)]
+    pub certifier: CertDesignators<CertUserIDEmailFileArgs,
+                                   CertifierPrefix,
+                                   OneValue,
+                                   CertifierDoc>,
 
     #[command(flatten)]
     pub cert: CertDesignators<

src/cli/types/cert_designator.rs

@@ -88,6 +88,19 @@ impl ArgumentPrefix for RevokerPrefix {
     }
 }
 
+/// "--certifier", "--certifier-userid", "--certifier-file", etc.
+pub type CertifierPrefix = ConcreteArgumentPrefix<typenum::U5>;
+
+impl ArgumentPrefix for CertifierPrefix {
+    fn prefix() -> &'static str {
+        "certifier-"
+    }
+
+    fn name() -> &'static str {
+        "certifier"
+    }
+}
+
 /// Adds a `--file` argument.
 pub type FileArg = typenum::U1;
 
@@ -220,6 +233,24 @@ impl AdditionalDocs for ToVerifyDoc {
     }
 }
 
+/// Documentation for certifier arguments.
+pub struct CertifierDoc {}
+impl AdditionalDocs for CertifierDoc {
+    fn help(arg: &'static str, help: &'static str) -> clap::builder::StyledStr {
+        match arg {
+            "file" =>
+                "Create the certification using the key read from PATH"
+                .into(),
+            _ => {
+                debug_assert!(help.starts_with("Use certificates"));
+                help.replace("Use certificates",
+                             "Create the certification using the key")
+                    .into()
+            },
+        }
+    }
+}
+
 /// A certificate designator.
 #[derive(Debug)]
 pub enum CertDesignator {

src/commands/pki/vouch/certify.rs

@@ -1,27 +1,16 @@
 use sequoia_openpgp as openpgp;
 use openpgp::Result;
-use openpgp::types::KeyFlags;
 
 use crate::Sq;
 use crate::cli::pki::vouch::certify;
-use crate::cli::types::FileStdinOrKeyHandle;
 use crate::commands::FileOrStdout;
 use crate::parse_notations;
 
 pub fn certify(sq: Sq, mut c: certify::Command)
     -> Result<()>
 {
-    let certifier: FileStdinOrKeyHandle = if let Some(file) = c.certifier_file {
-        assert!(c.certifier.is_none());
-        file.into()
-    } else if let Some(kh) = c.certifier {
-        kh.into()
-    } else {
-        panic!("clap enforces --certifier or --certifier-file is set");
-    };
-
-    let certifier = sq.lookup_one(
-        certifier, Some(KeyFlags::empty().set_certification()), true)?;
+    let certifier =
+        sq.resolve_cert(&c.certifier, sequoia_wot::FULLY_TRUSTED)?.0;
 
     let (cert, source) = sq.resolve_cert(&c.cert, sequoia_wot::FULLY_TRUSTED)?;
     if source.is_file() {