sq: Implement searching hkp servers by email address.

  - Fixes #389.

3 files changed, 33 insertions, 17 deletions

diff --git a/sq/src/sq-usage.rs b/sq/src/sq-usage.rs
index 1e232f26..db5e559d 100644
--- a/sq/src/sq-usage.rs
+++ b/sq/src/sq-usage.rs
@@ -323,7 +323,7 @@
 //!     -o, --output <FILE>    Sets the output file to use
 //!
 //! ARGS:
-//!     <QUERY>    Fingerprint or KeyID of the key to retrieve
+//!     <QUERY>    Fingerprint, KeyID, or email address of the cert(s) to retrieve
 //! ```
 //!
 //! ### Subcommand keyserver send
diff --git a/sq/src/sq.rs b/sq/src/sq.rs
index 266a8bd8..d75c2cae 100644
--- a/sq/src/sq.rs
+++ b/sq/src/sq.rs
@@ -22,6 +22,7 @@ use openpgp::{
     Fingerprint,
     KeyID,
     KeyHandle,
+    packet::UserID,
 };
 use crate::openpgp::{armor, Cert};
 use sequoia_autocrypt as autocrypt;
@@ -444,22 +445,35 @@ fn main() -> Result<()> {
                         }
                     };
 
-                    if handle.is_none() {
-                        Err(anyhow::anyhow!(
-                            "Malformed key handle: {:?}\n\
-                             (Note: only Fingerprints long KeyIDs are \
-                             supported.)", query))?;
-                    }
-                    let handle = handle.unwrap();
+                    if let Some(handle) = handle {
+                        let cert = rt.block_on(ks.get(handle))
+                            .context("Failed to retrieve cert")?;
 
-                    let mut output = create_or_stdout(m.value_of("output"), force)?;
-                    let cert = rt.block_on(ks.get(handle))
-                        .context("Failed to retrieve key")?;
-                    if ! m.is_present("binary") {
-                        cert.armored().serialize(&mut output)
+                        let mut output =
+                            create_or_stdout(m.value_of("output"), force)?;
+                        if ! m.is_present("binary") {
+                            cert.armored().serialize(&mut output)
+                        } else {
+                            cert.serialize(&mut output)
+                        }.context("Failed to serialize cert")?;
+                    } else if let Ok(Some(addr)) = UserID::from(query).email() {
+                        let certs = rt.block_on(ks.search(addr))
+                            .context("Failed to retrieve certs")?;
+
+                        let mut output =
+                            create_or_stdout_pgp(m.value_of("output"), force,
+                                                 m.is_present("binary"),
+                                                 armor::Kind::PublicKey)?;
+                        for cert in certs {
+                            cert.serialize(&mut output)
+                                .context("Failed to serialize cert")?;
+                        }
+                        output.finalize()?;
                     } else {
-                        cert.serialize(&mut output)
-                    }.context("Failed to serialize key")?;
+                        Err(anyhow::anyhow!(
+                            "Query must be a fingerprint, a keyid, \
+                             or an email address: {:?}", query))?;
+                    }
                 },
                 ("send",  Some(m)) => {
                     let mut input = open_or_stdin(m.value_of("input"))?;
diff --git a/sq/src/sq_cli.rs b/sq/src/sq_cli.rs
index c4c8fd73..9c56154b 100644
--- a/sq/src/sq_cli.rs
+++ b/sq/src/sq_cli.rs
@@ -304,8 +304,10 @@ pub fn build() -> App<'static, 'static> {
                                      .help("Don't ASCII-armor encode the OpenPGP data"))
                                 .arg(Arg::with_name("query").value_name("QUERY")
                                      .required(true)
-                                     .help("Fingerprint or KeyID of the key \
-                                            to retrieve")))
+                                     .help(
+                                         "Fingerprint, KeyID, or email \
+                                          address of the cert(s) to retrieve"
+                                     )))
                     .subcommand(SubCommand::with_name("send")
                                 .about("Sends a key")
                                 .arg(Arg::with_name("input").value_name("FILE")