From 16cf6172ce2df97a35e0a13e37c4df4bb28a8a23 Mon Sep 17 00:00:00 2001
From: Adam Wick <awick@uhsure.com>
Date: Wed, 22 May 2019 19:57:20 -0700
Subject: [PATCH] Support reading and writing ED25519 SSH keys.

---
 src/ssh/ed25519.rs | 58 ++++++++++++++++++++++++++++++++++++++++++++++
 src/ssh/errors.rs  | 10 ++++++++
 src/ssh/mod.rs     | 39 +++++++++++++++++++++++++++++++
 3 files changed, 107 insertions(+)
 create mode 100644 src/ssh/ed25519.rs

diff --git a/src/ssh/ed25519.rs b/src/ssh/ed25519.rs
new file mode 100644
index 0000000..c19dc51
--- /dev/null
+++ b/src/ssh/ed25519.rs
@@ -0,0 +1,58 @@
+use ed25519::{ED25519KeyPair,ED25519Private,ED25519Public};
+use std::io::{Read,Write};
+use ssh::errors::{SSHKeyParseError,SSHKeyRenderError};
+use ssh::frame::*;
+use ssh::SSHKey;
+
+impl SSHKey for ED25519KeyPair {
+    fn valid_keytype(s: &str) -> bool {
+        (s == "ssh-ed25519")
+    }
+
+    fn parse_ssh_public_info<I: Read>(inp: &mut I) -> Result<Self::Public,SSHKeyParseError>
+    {
+        let pubkey_type = parse_openssh_string(inp)?;
+        if !Self::valid_keytype(&pubkey_type) {
+            return Err(SSHKeyParseError::UnknownKeyType(pubkey_type));
+        }
+        let pubkey_bytes = parse_openssh_buffer(inp)?;
+        Ok(ED25519Public::new(&pubkey_bytes)?)
+    }
+
+    fn parse_ssh_private_info<I: Read>(inp: &mut I) -> Result<(Self::Private,String),SSHKeyParseError>
+    {
+        let check1 = parse_openssh_u32(inp)?;
+        let check2 = parse_openssh_u32(inp)?;
+        if check1 != check2 {
+            return Err(SSHKeyParseError::PrivateKeyCorruption);
+        }
+        let public = ED25519KeyPair::parse_ssh_public_info(inp)?;
+        let private_bytes = parse_openssh_buffer(inp)?; 
+        let private = ED25519Private::from_seed(&private_bytes[0..32]);
+        let comment = parse_openssh_string(inp)?;
+        for (idx,byte) in inp.bytes().enumerate() {
+            if ((idx+1) as u8) != byte? {
+                return Err(SSHKeyParseError::InvalidPadding);
+            }
+        }
+        assert_eq!(public, ED25519Public::from(&private));
+
+        Ok((private, comment))
+    }
+
+    fn render_ssh_public_info<O: Write>(&self, out: &mut O) -> Result<(),SSHKeyRenderError>
+    {
+        render_openssh_string(out, "ssh-ed25519")?;
+        render_openssh_buffer(out, &self.public.to_bytes())?;
+        Ok(())
+    }
+
+    fn render_ssh_private_info<O: Write>(&self, out: &mut O) -> Result<(),SSHKeyRenderError>
+    {
+        self.render_ssh_public_info(out)?;
+        let mut private_bytes = self.private.to_bytes();
+        private_bytes.append(&mut self.public.to_bytes());
+        render_openssh_buffer(out, &private_bytes)?;
+        Ok(())
+    }
+}
\ No newline at end of file
diff --git a/src/ssh/errors.rs b/src/ssh/errors.rs
index 7803b80..bda88f1 100644
--- a/src/ssh/errors.rs
+++ b/src/ssh/errors.rs
@@ -1,4 +1,5 @@
 use base64::DecodeError;
+use ed25519::ED25519PublicImportError;
 use std::io;
 
 #[derive(Debug)]
@@ -37,6 +38,15 @@ impl From<io::Error> for SSHKeyParseError {
     }
 }
 
+impl From<ED25519PublicImportError> for SSHKeyParseError {
+    fn from(e: ED25519PublicImportError) -> SSHKeyParseError {
+        match e {
+            ED25519PublicImportError::WrongNumberOfBytes(_) =>
+                SSHKeyParseError::InvalidPublicKeyMaterial
+        }
+    }
+}
+
 #[derive(Debug)]
 pub enum SSHKeyRenderError {
     IOError(io::Error),
diff --git a/src/ssh/mod.rs b/src/ssh/mod.rs
index bd03ea0..82d213f 100644
--- a/src/ssh/mod.rs
+++ b/src/ssh/mod.rs
@@ -1,5 +1,6 @@
 mod dsa;
 mod ecdsa;
+mod ed25519;
 mod errors;
 mod frame;
 mod rsa;
@@ -157,6 +158,8 @@ use dsa::{DSAKeyPair,DSAPublicKey,L1024N160};
 #[cfg(test)]
 use ecdsa::ECDSAPair;
 #[cfg(test)]
+use ed25519::ED25519KeyPair;
+#[cfg(test)]
 use rsa::{RSAPair,RSAPublic,SIGNING_HASH_SHA256};
 #[cfg(test)]
 use sha2::Sha256;
@@ -328,4 +331,40 @@ fn ecdsa_examples() {
         }
     }
 }
+ 
+#[cfg(test)]
+#[test]
+fn ed25519_examples() {
+    let test_files = ["ed25519-1", "ed25519-2", "ed25519-3"];
+
+    for file in test_files.iter() {
+        let path = format!("testdata/ssh/{}",file);
+        match load_ssh_keyfile::<ED25519KeyPair,String>(path) {
+            Err(e) =>
+                assert!(false, "SSH ED25519 parse error: {:?}", e),
+            Ok((keypair,comment)) => {
+                // first see if this roundtrips
+                let buffer = vec![0,1,2,4,5,6,9];
+                let sig = keypair.private.sign(&buffer);
+                assert!(keypair.public.verify(&buffer, &sig));
+                match encode_ssh(&keypair, &comment) {
+                    Err(e) =>
+                        assert!(false, "SSH ED25519 encoding error: {:?}", e),
+                    Ok(coded) => {
+                       match decode_ssh(&coded) {
+                           Err(e) =>
+                             assert!(false, "SSSH ECDSA redecoding error: {:?}", e),
+                           Ok((keypair2, comment2)) => {
+                               let _ : ED25519KeyPair = keypair2;
+                               assert_eq!(keypair.public, keypair2.public, "public key mismatch");
+                               assert_eq!(keypair.private, keypair2.private, "public key mismatch");
+                               assert_eq!(comment, comment2, "comment mismatch");
+                           }
+                       } 
+                    }
+                }
+            }
+        }
+    }
+}
  
\ No newline at end of file