Initial commit

src/packet.rs

@@ -0,0 +1,143 @@
+// This file is part of ctap, a Rust implementation of the FIDO2 protocol.
+// Copyright (c) Ariën Holthuizen <contact@ardaxi.com>
+// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
+// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
+// http://opensource.org/licenses/MIT>, at your option. This file may not be
+// copied, modified, or distributed except according to those terms.
+use num_traits::{FromPrimitive, ToPrimitive};
+
+static FRAME_INIT: u8 = 0x80;
+
+#[repr(u8)]
+#[derive(FromPrimitive, ToPrimitive, PartialEq)]
+pub enum CtapCommand {
+    Invalid = 0x00,
+    Ping = 0x01,
+    Msg = 0x03,
+    Lock = 0x04,
+    Init = 0x06,
+    Wink = 0x08,
+    Cbor = 0x10,
+    Cancel = 0x11,
+    Keepalive = 0x3b,
+    Error = 0x3f,
+}
+
+impl CtapCommand {
+    pub fn to_wire_format(&self) -> u8 {
+        match self.to_u8() {
+            Some(x) => x,
+            None => 0x00,
+        }
+    }
+}
+
+#[repr(u8)]
+#[derive(FromPrimitive, Fail, Debug)]
+pub enum CtapError {
+    #[fail(display = "The command in the request is invalid")]
+    InvalidCmd = 0x01,
+    #[fail(display = "The parameter(s) in the request is invalid")]
+    InvalidPar = 0x02,
+    #[fail(display = "The length field (BCNT) is invalid for the request ")]
+    InvalidLen = 0x03,
+    #[fail(display = "The sequence does not match expected value ")]
+    InvalidSeq = 0x04,
+    #[fail(display = "The message has timed out ")]
+    MsgTimeout = 0x05,
+    #[fail(display = "The device is busy for the requesting channel ")]
+    ChannelBusy = 0x06,
+    #[fail(display = "Command requires channel lock ")]
+    LockRequired = 0x0A,
+    #[fail(display = "Reserved error")]
+    NA = 0x0B,
+    #[fail(display = "Unspecified error")]
+    Other = 0x7F,
+}
+
+pub trait Packet {
+    fn from_wire_format(data: &[u8]) -> Self;
+
+    fn to_wire_format(&self) -> &[u8];
+}
+
+pub struct InitPacket(pub [u8; 65]);
+
+impl InitPacket {
+    pub fn new(cid: &[u8], cmd: &CtapCommand, size: u16, payload: &[u8]) -> InitPacket {
+        let mut packet = InitPacket([0; 65]);
+        packet.0[1..5].copy_from_slice(cid);
+        packet.0[5] = FRAME_INIT | cmd.to_wire_format();
+        packet.0[6] = ((size >> 8) & 0xff) as u8;
+        packet.0[7] = (size & 0xff) as u8;
+        packet.0[8..(payload.len() + 8)].copy_from_slice(payload);
+        packet
+    }
+
+    pub fn cid(&self) -> &[u8] {
+        &self.0[1..5]
+    }
+
+    pub fn cmd(&self) -> CtapCommand {
+        match CtapCommand::from_u8(self.0[5] ^ FRAME_INIT) {
+            Some(cmd) => cmd,
+            None => CtapCommand::Invalid,
+        }
+    }
+
+    pub fn size(&self) -> u16 {
+        ((u16::from(self.0[6])) << 8) | u16::from(self.0[7])
+    }
+
+    pub fn payload(&self) -> &[u8] {
+        &self.0[8..65]
+    }
+}
+
+impl Packet for InitPacket {
+    fn from_wire_format(data: &[u8]) -> InitPacket {
+        let mut packet = InitPacket([0; 65]);
+        packet.0[1..65].copy_from_slice(data);
+        packet
+    }
+
+    fn to_wire_format(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+pub struct ContPacket(pub [u8; 65]);
+
+impl ContPacket {
+    pub fn new(cid: &[u8], seq: u8, payload: &[u8]) -> ContPacket {
+        let mut packet = ContPacket([0; 65]);
+        packet.0[1..5].copy_from_slice(cid);
+        packet.0[5] = seq;
+        packet.0[6..(payload.len() + 6)].copy_from_slice(payload);
+        packet
+    }
+
+    pub fn cid(&self) -> &[u8] {
+        &self.0[1..5]
+    }
+
+    pub fn seq(&self) -> u8 {
+        self.0[5]
+    }
+
+    pub fn payload(&self) -> &[u8] {
+        &self.0[6..65]
+    }
+}
+
+impl Packet for ContPacket {
+    fn from_wire_format(data: &[u8]) -> ContPacket {
+        let mut packet = ContPacket([0; 65]);
+        packet.0[1..65].copy_from_slice(data);
+        packet
+    }
+
+    fn to_wire_format(&self) -> &[u8] {
+        &self.0
+    }
+}