add openpgp, dep oss rust

src/pgp_util.rs

@@ -0,0 +1,65 @@
+extern crate sequoia_openpgp as openpgp;
+use crate::openpgp::armor;
+use std::{
+    fs::File,
+    io::{
+        Write,
+        BufWriter,
+    },
+};
+use rust_util::{
+    XResult,
+    new_box_error,
+};
+use openpgp::{
+    types::KeyFlags,
+    TPK,
+    parse::Parse,
+    serialize::stream::{
+        Recipient,
+        Message,
+        Encryptor,
+        LiteralWriter,
+    },
+};
+
+pub struct OpenPGPClient {
+    pub tpk: TPK,
+}
+
+impl OpenPGPClient {
+    pub fn from_file(file: &str) -> XResult<OpenPGPClient> {
+        Ok(OpenPGPClient{
+            tpk: TPK::from_file(std::path::Path::new(file))?,
+        })
+    }
+
+    pub fn from_bytes(bs: &[u8]) -> XResult<OpenPGPClient> {
+        Ok(OpenPGPClient{
+            tpk: TPK::from_bytes(&bs)?,
+        })
+    }
+
+    pub fn encrypt_file(&self, from_file: &str, to_file: &str, armor: bool) -> XResult<()> {
+        let recipient: Recipient = match self.tpk.keys_valid()
+            .key_flags(KeyFlags::default().set_encrypt_at_rest(true).set_encrypt_for_transport(true))
+            .map(|(_, _, key)| key.into())
+            .nth(0) {
+                None => return Err(new_box_error("Encryption key not found in TPK")),
+                Some(r) => r,
+            };
+        let message = if armor {
+            Message::new(armor::Writer::new(std::io::stdout(), armor::Kind::Message, &[])?)
+        } else {
+            Message::new(BufWriter::new(File::open(to_file)?))
+        };
+        let encryptor = Encryptor::for_recipient(message, recipient).build()?;
+        let mut pgp_encrypt_writer = LiteralWriter::new(encryptor).build()?;
+        // TODO read from from_file
+        pgp_encrypt_writer.write_all(b"Hello world.")?;
+        pgp_encrypt_writer.finalize()?;
+                                    
+        Ok(())
+    }
+}
+