/// This program demonstrates how to make a detached signature.
use std::env;
use std::io;
extern crate openpgp;
use openpgp::armor;
use openpgp::serialize::stream::{wrap, Signer};
fn main() {
let args: Vec<String> = env::args().collect();
if args.len() < 2 {
panic!("A simple filter creating a detached signature.\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::Signature, &[][..])
.expect("Failed to create armored writer.");
// Now, create a signer that emits a detached signature.
let mut signer = Signer::detached(
wrap(sink), &tsks.iter().collect::<Vec<&openpgp::TPK>>())
.expect("Failed to create signer");
// Finally, just copy all the data.
io::copy(&mut io::stdin(), &mut signer)
.expect("Failed to sign data");
// Teardown the stack to ensure all the data is written.
signer.finalize()
.expect("Failed to write data");
}