Align sq download with sq verify.

NEWS

@@ -65,6 +65,10 @@
      has its desired name.  There are two benefits: no one sees
      partially written files, and one can safely use the same file as
      input and output.
+   - `sq download --signature` is now called `sq download
+     --signature-url`.
+   - `sq download` now requires one of `--signature-url`, `--message`,
+     or `--cleartext` like `sq verify`.
 
 * Changes in 0.41.0
 ** New functionality

src/cli/download.rs

@@ -1,6 +1,6 @@
 //! Command-line parser for `sq download`.
 
-use clap::Parser;
+use clap::{ArgGroup, Parser};
 
 use crate::cli::examples;
 use examples::Action;
@@ -21,7 +21,7 @@ const EXAMPLES: Actions = Actions {
         ).command(&[
             "sq", "download",
             "--url=file://debian/SHA512SUMS",
-            "--signature=file://debian/SHA512SUMS.sign",
+            "--signature-url=file://debian/SHA512SUMS.sign",
             "--signer=DF9B9C49EAA9298432589D76DA87E80D6294BE9B",
             "--output=SHA512SUMS",
         ]).build(),
@@ -42,6 +42,8 @@ authenticated, the data is deleted, if possible.
 ",
     after_help = EXAMPLES,
 )]
+#[clap(group(ArgGroup::new("kind")
+             .args(&["detached", "message", "cleartext"]).required(true)))]
 pub struct Command {
     #[clap(
         long = "url",
@@ -51,7 +53,7 @@ pub struct Command {
     pub url: String,
 
     #[clap(
-        long = "signature",
+        long = "signature-url",
         value_name = "URL",
         help = "URL of the signature",
         long_help = "\
@@ -63,7 +65,21 @@ If no signature is specified, then the signature is assumed to be \
 inline.
 ",
     )]
-    pub signature: Option<String>,
+    pub detached: Option<String>,
+
+    #[clap(
+        long = "message",
+        value_name = "SIG",
+        help = "Verify an inline signed message"
+    )]
+    pub message: bool,
+
+    #[clap(
+        long = "cleartext",
+        value_name = "SIG",
+        help = "Verify a cleartext-signed message"
+    )]
+    pub cleartext: bool,
 
     #[command(flatten)]
     pub signers: CertDesignators<FileCertUserIDEmailDomainArgs,

src/commands/download.rs

@@ -174,7 +174,7 @@ pub fn dispatch(sq: Sq, c: download::Command)
     -> Result<()>
 {
     let url = c.url;
-    let signature = c.signature;
+    let signature_url = c.detached;
     let signatures = c.signatures;
     let signers =
         sq.resolve_certs_or_fail(&c.signers, sequoia_wot::FULLY_TRUSTED)?;
@@ -285,9 +285,10 @@ pub fn dispatch(sq: Sq, c: download::Command)
     // than 'static.  Instead, we set up a scoped thread, which can
     // use variables with lifetimes less than static, and then do the
     // processing there.
+    let signature_url_ = signature_url.clone();
     let (mut data_file, signature_file) = std::thread::scope(|scope| {
         // Schedule the download of the signature.
-        if let Some(ref url) = signature {
+        if let Some(ref url) = signature_url_ {
             let sig_file = tempfile::NamedTempFile::new()?;
 
             let getter = get!(
@@ -508,7 +509,7 @@ pub fn dispatch(sq: Sq, c: download::Command)
                     "Internal error while downloading data file"));
             };
 
-            if signature.is_some() && signature_file.is_none() {
+            if signature_url_.is_some() && signature_file.is_none() {
                 return Err(anyhow::anyhow!(
                     "Internal error while downloading signature file"));
             }
@@ -533,6 +534,8 @@ pub fn dispatch(sq: Sq, c: download::Command)
             data_file.as_ref().try_clone()?, data_file.path(),
             Default::default())?.into_boxed(),
         signature_file.as_ref().map(|f| f.path().to_path_buf()),
+        "--signature-url",
+        signature_url.map(PathBuf::from),
         &mut output_file,
         signatures,
         signers);

src/commands/verify.rs

@@ -42,6 +42,8 @@ pub fn dispatch(sq: Sq, command: cli::verify::Command)
         sq.resolve_certs_or_fail(&command.signers, sequoia_wot::FULLY_TRUSTED)?;
 
     let result = verify(sq, input,
+                        command.detached.clone(),
+                        "--signature-file",
                         command.detached,
                         &mut output, signatures, signers);
     if result.is_err() {
@@ -63,6 +65,8 @@ pub fn dispatch(sq: Sq, command: cli::verify::Command)
 pub fn verify(mut sq: Sq,
               input: Box<dyn BufferedReader<Cookie>>,
               detached: Option<PathBuf>,
+              detached_sig_arg: &str,
+              detached_sig_value: Option<PathBuf>,
               output: &mut dyn io::Write,
               signatures: usize, certs: Vec<Cert>)
               -> Result<()> {
@@ -71,7 +75,8 @@ pub fn verify(mut sq: Sq,
 
         let (kind, sig) = Kind::identify(&mut sq, sig)?;
         kind.expect_or_else(&sq, "verify", Kind::DetachedSig,
-                            "--signature-file", Some(&sig_path))?;
+                            detached_sig_arg,
+                            detached_sig_value.as_deref())?;
 
         Some(sig)
     } else {