1 files changed, 98 insertions, 0 deletions
diff --git a/openpgp/examples/notarize.rs b/openpgp/examples/notarize.rs
new file mode 100644
index 00000000..d3426131
--- /dev/null
+++ b/openpgp/examples/notarize.rs
@@ -0,0 +1,98 @@
+/// This program demonstrates how to notarize an OpenPGP message.
+
+use std::env;
+use std::io;
+
+extern crate openpgp;
+use openpgp::{
+    armor,
+    Packet,
+    constants::DataFormat,
+    parse::PacketParserResult,
+    serialize::Serialize,
+};
+use openpgp::serialize::stream::{wrap, LiteralWriter, Signer};
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+    if args.len() < 2 {
+        panic!("A simple notarizing filter.\n\n\
+                Usage: {} <secret-keyfile> [<secret-keyfile>...] \
+                <input >output\n", args[0]);
+    }
+
+    // Read the transferable secret keys from the given files.
+    let tsks: Vec<openpgp::TPK> = args[1..].iter().map(|f| {
+        openpgp::TPK::from_reader(
+            // Use an openpgp::Reader so that we accept both armored
+            // and plain PGP data.
+            openpgp::Reader::from_file(f)
+                .expect("Failed to open file"))
+            .expect("Failed to read key")
+    }).collect();
+
+    // Compose a writer stack corresponding to the output format and
+    // packet structure we want.  First, we want the output to be
+    // ASCII armored.
+    let sink = armor::Writer::new(io::stdout(), armor::Kind::Message, &[][..])
+        .expect("Failed to create an armored writer.");
+
+    // Now, create a signer that emits a detached signature.
+    let mut signer = Signer::new(
+        wrap(sink), &tsks.iter().collect::<Vec<&openpgp::TPK>>())
+        .expect("Failed to create signer");
+
+    // Create a parser for the message to be notarized.
+    let mut input = io::stdin();
+    let mut ppr
+        = openpgp::parse::PacketParser::from_reader(
+            openpgp::Reader::from_reader(&mut input)
+                .expect("Failed to build reader"))
+        .expect("Failed to build parser");
+
+    while let PacketParserResult::Some(mut pp) = ppr {
+        if ! pp.possible_message() {
+            panic!("Malformed OpenPGP message");
+        }
+
+        match pp.packet {
+            Packet::PKESK(_) | Packet::SKESK(_) =>
+                panic!("Encrypted messages are not supported"),
+            Packet::OnePassSig(ref ops) =>
+                ops.serialize(&mut signer).expect("Failed to serialize"),
+            Packet::Literal(_) => {
+                // Then, create a literal writer to wrap the data in a
+                // literal message packet.
+                let mut literal =
+                    LiteralWriter::new(signer, DataFormat::Binary, None, None)
+                    .expect("Failed to create literal writer");
+
+                // Finally, just copy all the data.
+                io::copy(&mut pp, &mut literal)
+                    .expect("Failed to sign data");
+
+                signer = literal.finalize_one()
+                    .expect("Failed to sign data")
+                    .unwrap();
+            },
+            Packet::Signature(ref sig) =>
+                sig.serialize(&mut signer).expect("Failed to serialize"),
+            _ => (),
+        }
+
+        let (_, _, ppr_tmp, _) = pp.recurse()
+            .expect("Failed to recurse");
+        ppr = ppr_tmp;
+    }
+    if let PacketParserResult::EOF(eof) = ppr {
+        if ! eof.is_message() {
+            panic!("Malformed OpenPGP message")
+        }
+    } else {
+        unreachable!()
+    }
+
+    // Teardown the stack to ensure all the data is written.
+    signer.finalize()
+        .expect("Failed to write data");
+}