ECDSA SSH key support.

src/ecdsa/curve.rs

@@ -1,11 +1,12 @@
 use cryptonum::signed::{I192,I256,I384,I576};
 use cryptonum::unsigned::{Decoder};
 use cryptonum::unsigned::{U192,U256,U384,U576};
+use std::fmt::Debug;
 
 #[allow(non_snake_case)]
 pub trait EllipticCurve {
     type Unsigned : Clone;
-    type Signed : Clone;
+    type Signed : Clone + Debug + PartialEq;
 
     fn size() -> usize;
     fn p() -> Self::Unsigned;
@@ -18,6 +19,7 @@ pub trait EllipticCurve {
     fn Gy() -> Self::Signed;
 }
 
+#[derive(Debug,PartialEq)]
 pub enum P192 {}
 
 impl EllipticCurve for P192 {
@@ -61,6 +63,7 @@ impl EllipticCurve for P192 {
     }
 }
 
+#[derive(Debug,PartialEq)]
 pub enum P224 {}
 
 impl EllipticCurve for P224 {
@@ -143,6 +146,7 @@ impl EllipticCurve for P224 {
     }
 }
 
+#[derive(Debug,PartialEq)]
 pub enum P256 {}
 
 impl EllipticCurve for P256 {
@@ -226,6 +230,7 @@ impl EllipticCurve for P256 {
     }
 }
 
+#[derive(Debug,PartialEq)]
 pub enum P384 {}
 
 impl EllipticCurve for P384 {
@@ -322,6 +327,7 @@ impl EllipticCurve for P384 {
     }
 }
 
+#[derive(Debug,PartialEq)]
 pub enum P521 {}
 
 impl EllipticCurve for P521 {

src/ecdsa/point.rs

@@ -20,6 +20,7 @@ pub trait ECCPoint : Sized {
     }
 }
 
+#[derive(Debug,PartialEq)]
 pub struct Point<T: EllipticCurve>
 {
     pub x: T::Signed,

src/ecdsa/private.rs

@@ -5,9 +5,18 @@ use dsa::rfc6979::{DSASignature,KIterator,bits2int};
 use ecdsa::curve::{EllipticCurve,P192,P224,P256,P384,P521};
 use ecdsa::point::{ECCPoint,Point};
 use hmac::{Hmac,Mac};
+use std::fmt;
 
+#[derive(PartialEq)]
 pub struct ECCPrivateKey<Curve: EllipticCurve> {
-    d: Curve::Unsigned
+    pub(crate) d: Curve::Unsigned
+}
+
+impl<Curve: EllipticCurve> fmt::Debug for ECCPrivateKey<Curve> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(),fmt::Error>
+    {
+        f.write_str("<ECCPrivateKey>")
+    }
 }
 
 pub enum ECDSAPrivate {

src/ecdsa/public.rs

@@ -8,8 +8,9 @@ use hmac::{Hmac,Mac};
 use simple_asn1::{ASN1Block,ASN1Class,ASN1DecodeErr,ASN1EncodeErr,FromASN1,ToASN1};
 use std::cmp::min;
 
+#[derive(Debug,PartialEq)]
 pub struct ECCPublicKey<Curve: EllipticCurve> {
-    q: Point<Curve>
+    pub(crate) q: Point<Curve>
 }
 
 pub enum ECDSAPublic {

src/ssh/ecdsa.rs

@@ -1,5 +1,8 @@
+use cryptonum::signed::*;
 use cryptonum::unsigned::*;
 use ecdsa::{ECDSAPair,ECDSAPublic,ECCPublicKey,ECDSAPrivate,ECCPrivateKey};
+use ecdsa::curve::{P256,P384,P521};
+use ecdsa::point::Point;
 use std::io::{Read,Write};
 use ssh::errors::{SSHKeyParseError,SSHKeyRenderError};
 use ssh::frame::*;
@@ -21,15 +24,45 @@ impl SSHKey for ECDSAPair {
         // that we didn't know the number format was the same as the buffer
         // one), but we need to infer what kind of key this is, and this appears
         // to be the easiest / fastest way.
-        let mut ebuf = parse_openssh_buffer(inp)?;
+        let curve = parse_openssh_string(inp)?;
-        let mut ibuf = parse_openssh_buffer(inp)?;
+        match curve.as_ref() {
-
+            "nistp256" => {
-        while ebuf[0] == 0 { ebuf.remove(0); }
+                let val = parse_openssh_buffer(inp)?;
-        while ibuf[0] == 0 { ibuf.remove(0); }
+                if val[0] != 4 || val.len() != 65 {
-
+                    return Err(SSHKeyParseError::InvalidECPointCompression);
-        println!("ebuf: {:?}", ebuf);
+                }
-        println!("ibuf: {:?}", ibuf);
+                let x = U256::from_bytes(&val[1..33]);
-        panic!("parse public info")
+                let y = U256::from_bytes(&val[33..]);
+                let p = Point::<P256>{ x: I256::from(x), y: I256::from(y) };
+                let pbl = ECCPublicKey::<P256>::new(p);
+                Ok(ECDSAPublic::P256(pbl))
+            }
+            "nistp384" => {
+                let val = parse_openssh_buffer(inp)?;
+                if val[0] != 4 || val.len() != 97 {
+                    return Err(SSHKeyParseError::InvalidECPointCompression);
+                }
+                let x = U384::from_bytes(&val[1..49]);
+                let y = U384::from_bytes(&val[49..]);
+                let p = Point::<P384>{ x: I384::from(x), y: I384::from(y) };
+                let pbl = ECCPublicKey::<P384>::new(p);
+                Ok(ECDSAPublic::P384(pbl))
+            }
+            "nistp521" => {
+                let val = parse_openssh_buffer(inp)?;
+                if val[0] != 4 || val.len() != 133 {
+                    return Err(SSHKeyParseError::InvalidECPointCompression);
+                }
+                let x = U576::from_bytes(&val[1..67]);
+                let y = U576::from_bytes(&val[67..]);
+                let p = Point::<P521>{ x: I576::from(x), y: I576::from(y) };
+                let pbl = ECCPublicKey::<P521>::new(p);
+                Ok(ECDSAPublic::P521(pbl))
+            }
+            _ => {
+                return Err(SSHKeyParseError::UnknownECDSACurve(curve))
+            }
+        }
     }
 
     fn parse_ssh_private_info<I: Read>(inp: &mut I) -> Result<(Self::Private,String),SSHKeyParseError>
@@ -39,11 +72,31 @@ impl SSHKey for ECDSAPair {
         if check1 != check2 {
             return Err(SSHKeyParseError::PrivateKeyCorruption);
         }
-        let privkey_type = parse_openssh_string(inp)?;
+        let res = match ECDSAPair::parse_ssh_public_info(inp)? {
-        if !Self::valid_keytype(&privkey_type) {
+            ECDSAPublic::P192(_) => return Err(SSHKeyParseError::PrivateKeyCorruption),
-            return Err(SSHKeyParseError::InconsistentKeyTypes("ssh-rsa".to_string(), privkey_type));
+            ECDSAPublic::P224(_) => return Err(SSHKeyParseError::PrivateKeyCorruption),
+            ECDSAPublic::P256(_) => {
+                let mut dbytes = parse_openssh_buffer(inp)?;
+                while dbytes[0] == 0 { dbytes.remove(0); }
+                assert!(dbytes.len() <= 32);
+                let d = U256::from_bytes(&dbytes);
+                ECDSAPrivate::P256(ECCPrivateKey::<P256>::new(d))
             }
-
+            ECDSAPublic::P384(_) => {
+                let mut dbytes = parse_openssh_buffer(inp)?;
+                while dbytes[0] == 0 { dbytes.remove(0); }
+                assert!(dbytes.len() <= 48);
+                let d = U384::from_bytes(&dbytes);
+                ECDSAPrivate::P384(ECCPrivateKey::<P384>::new(d))
+            }
+            ECDSAPublic::P521(_) => {
+                let mut dbytes = parse_openssh_buffer(inp)?;
+                while dbytes[0] == 0 { dbytes.remove(0); }
+                assert!(dbytes.len() <= 66);
+                let d = U576::from_bytes(&dbytes);
+                ECDSAPrivate::P521(ECCPrivateKey::<P521>::new(d))
+            }
+        };
         let comment = parse_openssh_string(inp)?;
         for (idx,byte) in inp.bytes().enumerate() {
             if ((idx+1) as u8) != byte? {
@@ -51,28 +104,70 @@ impl SSHKey for ECDSAPair {
             }
         }
 
-        panic!("parse private_info")
+        Ok((res, comment))
     }
 
     fn render_ssh_public_info<O: Write>(&self, out: &mut O) -> Result<(),SSHKeyRenderError>
     {
         render_openssh_string(out, "ssh-ecdsa")?;
-        panic!("render public info")
+        match self {
+            ECDSAPair::P192(_,_) =>
+                return Err(SSHKeyRenderError::IllegalECDSAKeyType("P192".to_string())),
+            ECDSAPair::P224(_,_) =>
+                return Err(SSHKeyRenderError::IllegalECDSAKeyType("P224".to_string())),
+            ECDSAPair::P256(pu,_) => {
+                render_openssh_string(out, "nistp256")?;
+                let mut vec = Vec::with_capacity(66);
+                vec.write(&[4u8])?;
+                render_number(256, &mut vec, &U256::from(pu.q.x.clone()))?;
+                render_number(256, &mut vec, &U256::from(pu.q.y.clone()))?;
+                render_openssh_buffer(out, &vec)?;
+            }
+            ECDSAPair::P384(pu,_) => {
+                render_openssh_string(out, "nistp384")?;
+                let mut vec = Vec::with_capacity(66);
+                vec.write(&[4u8])?;
+                render_number(384, &mut vec, &U384::from(pu.q.x.clone()))?;
+                render_number(384, &mut vec, &U384::from(pu.q.y.clone()))?;
+                render_openssh_buffer(out, &vec)?;
+            }
+            ECDSAPair::P521(pu,_) => {
+                render_openssh_string(out, "nistp521")?;
+                let mut vec = Vec::with_capacity(66);
+                vec.write(&[4u8])?;
+                render_number(521, &mut vec, &U576::from(pu.q.x.clone()))?;
+                render_number(521, &mut vec, &U576::from(pu.q.y.clone()))?;
+                render_openssh_buffer(out, &vec)?;
+            }
+        }
+        Ok(())
     }
 
-    fn render_ssh_private_info<O: Write>(&self, out: &mut O, comment: &str) -> Result<(),SSHKeyRenderError>
+    fn render_ssh_private_info<O: Write>(&self, out: &mut O) -> Result<(),SSHKeyRenderError>
     {
-        render_openssh_u32(out, 0xDEADBEEF)?; // FIXME: Any reason for this to be random?
+        self.render_ssh_public_info(out)?;
-        render_openssh_u32(out, 0xDEADBEEF)?; // ditto
+        match self {
-        render_openssh_string(out, "ssh-ecdsa")?;
+            ECDSAPair::P192(_,_) =>
-        panic!("render private info");
+                return Err(SSHKeyRenderError::IllegalECDSAKeyType("P192".to_string())),
-        render_openssh_string(out, comment)?;
+            ECDSAPair::P224(_,_) =>
-        // add some padding (not quite sure why)
+                return Err(SSHKeyRenderError::IllegalECDSAKeyType("P224".to_string())),
-        let mut i = comment.len();
+            ECDSAPair::P256(_,pr) => { render_openssh_u32(out, 256/8)?; render_number(256, out, &pr.d)?; }
-        while (i % 16) != 0 {
+            ECDSAPair::P384(_,pr) => { render_openssh_u32(out, 384/8)?; render_number(384, out, &pr.d)?; }
-            out.write(&[(i - comment.len() + 1) as u8])?;
+            ECDSAPair::P521(_,pr) => { render_openssh_u32(out, 528/8)?; render_number(521, out, &pr.d)?; }
-            i += 1;
         }
         Ok(())
     }
 }
+
+fn render_number<O,N>(bitlen: usize, out: &mut O, val: &N) -> Result<(),SSHKeyRenderError>
+ where
+  O: Write,
+  N: Encoder
+{
+    let mut outvec = Vec::new();
+    outvec.write(&val.to_bytes())?;
+    while outvec.len() < ((bitlen + 7) / 8) { outvec.insert(0,0); }
+    while outvec.len() > ((bitlen + 7) / 8) { outvec.remove(0);   }
+    out.write(&outvec)?;
+    Ok(())
+}

src/ssh/errors.rs

@@ -20,7 +20,9 @@ pub enum SSHKeyParseError
     InvalidPrivateKeyValue,
     InvalidPadding,
     InvalidPublicKeyType,
-    BrokenPublicKeyLine
+    BrokenPublicKeyLine,
+    UnknownECDSACurve(String),
+    InvalidECPointCompression
 }
 
 impl From<DecodeError> for SSHKeyParseError {
@@ -39,7 +41,8 @@ impl From<io::Error> for SSHKeyParseError {
 pub enum SSHKeyRenderError {
     IOError(io::Error),
     StringTooLong,
-    BufferTooLarge
+    BufferTooLarge,
+    IllegalECDSAKeyType(String)
 }
 
 impl From<io::Error> for SSHKeyRenderError {

src/ssh/mod.rs

@@ -1,4 +1,5 @@
 mod dsa;
+mod ecdsa;
 mod errors;
 mod frame;
 mod rsa;
@@ -154,6 +155,8 @@ pub fn write_ssh_keyfile<KP,P>(path: P, x: &KP, comment: &str) -> Result<(),SSHK
 #[cfg(test)]
 use dsa::{DSAKeyPair,DSAPublicKey,L1024N160};
 #[cfg(test)]
+use ecdsa::ECDSAPair;
+#[cfg(test)]
 use rsa::{RSAPair,RSAPublic,SIGNING_HASH_SHA256};
 #[cfg(test)]
 use sha2::Sha256;
@@ -259,3 +262,70 @@ fn rsa_examples() {
         }
     }
 }
+
+#[cfg(test)]
+#[test]
+fn ecdsa_examples() {
+    let test_files = ["ecdsa256-1", "ecdsa256-2", "ecdsa256-3",
+                      "ecdsa384-1", "ecdsa384-2", "ecdsa384-3",
+                      "ecdsa521-1", "ecdsa521-2", "ecdsa521-3"];
+
+    for file in test_files.iter() {
+        let path = format!("testdata/ssh/{}",file);
+        match load_ssh_keyfile::<ECDSAPair,String>(path) {
+            Err(e) =>
+                assert!(false, "SSH ECDSA parse error: {:?}", e),
+            Ok((keypair,comment)) => {
+                // first see if this roundtrips
+                let buffer = vec![0,1,2,4,5,6,9];
+                match keypair {
+                    ECDSAPair::P192(_,_) =>
+                        assert!(false, "Somehow got a P192 in read test"),
+                    ECDSAPair::P224(_,_) =>
+                        assert!(false, "Somehow got a P224 in read test"),
+                    ECDSAPair::P256(ref pu, ref pr) => {
+                        let sig = pr.sign::<Sha256>(&buffer);
+                        assert!(pu.verify::<Sha256>(&buffer, &sig));
+                    }
+                    ECDSAPair::P384(ref pu, ref pr) => {
+                        let sig = pr.sign::<Sha256>(&buffer);
+                        assert!(pu.verify::<Sha256>(&buffer, &sig));
+                    }
+                    ECDSAPair::P521(ref pu, ref pr) => {
+                        let sig = pr.sign::<Sha256>(&buffer);
+                        assert!(pu.verify::<Sha256>(&buffer, &sig));
+                    }
+                }
+                // encode this, parse it again
+                match encode_ssh(&keypair, &comment) {
+                    Err(e) =>
+                        assert!(false, "SSH ECDSA encoding error: {:?}", e),
+                    Ok(coded) => {
+                       match (decode_ssh(&coded), keypair) {
+                           (Err(e), _) =>
+                             assert!(false, "SSSH ECDSA redecoding error: {:?}", e),
+                           (Ok((ECDSAPair::P256(pu2, pr2), comment2)), ECDSAPair::P256(pu,pr)) => {
+                               assert_eq!(pu, pu2, "public key mismatch");
+                               assert_eq!(pr, pr2, "public key mismatch");
+                               assert_eq!(comment, comment2, "comment mismatch");
+                           }
+                           (Ok((ECDSAPair::P384(pu2, pr2), comment2)), ECDSAPair::P384(pu,pr)) => {
+                               assert_eq!(pu, pu2, "public key mismatch");
+                               assert_eq!(pr, pr2, "public key mismatch");
+                               assert_eq!(comment, comment2, "comment mismatch");
+                           }
+                           (Ok((ECDSAPair::P521(pu2, pr2), comment2)), ECDSAPair::P521(pu,pr)) => {
+                               assert_eq!(pu, pu2, "public key mismatch");
+                               assert_eq!(pr, pr2, "public key mismatch");
+                               assert_eq!(comment, comment2, "comment mismatch");
+                           }
+                           _ =>
+                             assert!(false, "Failed to accurately re-parse key")
+                       } 
+                    }
+                }
+            }
+        }
+    }
+}
+