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/target
**/*.rs.bk
Cargo.lock
src/bin

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[package]
name = "ctap"
description = "A Rust implementation of the FIDO2 CTAP protocol"
version = "0.1.0"
license = "Apache-2.0/MIT"
homepage = "https://github.com/ArdaXi/ctap"
repository = "https://github.com/ArdaXi/ctap"
authors = ["Arda Xi <arda@ardaxi.com>"]
edition = "2018"
[dependencies]
rand = "0.6"
failure = "0.1"
failure_derive = "0.1"
num-traits = "0.2"
num-derive = "0.2"
byteorder = "1"
cbor-codec = "0.7"
ring = "0.13"
untrusted = "0.6"
rust-crypto = "0.2"

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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
# ctap
ctap is a library implementing the [FIDO2 CTAP](https://fidoalliance.org/specs/fido-v2.0-id-20180227/fido-client-to-authenticator-protocol-v2.0-id-20180227.html) protocol.
## Usage example
```rust
let devices = ctap::get_devices()?;
let device_info = &devices[0];
let mut device = ctap::FidoDevice::new(device_info)?;
// This can be omitted if the FIDO device is not configured with a PIN.
let pin = "test";
device.unlock(pin)?;
// In a real application these values would come from the requesting app.
let rp_id = "rp_id";
let user_id = [0];
let user_name = "user_name";
let client_data_hash = [0; 32];
let cred = device.make_credential(
rp_id,
&user_id,
user_name,
&client_data_hash
)?;
// In a real application the credential would be stored and used later.
let result = device.get_assertion(&cred, &client_data_hash);
```
## Limitations
Currently, this library only supports Linux. Testing and contributions for
other platforms is welcome.
## License
Licensed under either of
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally
submitted for inclusion in the work by you, as defined in the Apache-2.0
license, shall be dual licensed as above, without any additional terms or
conditions.

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Copyright (c) Ariën Holthuizen <contact@ardaxi.com>
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// 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 cbor_codec::{Config, Encoder, Decoder, GenericDecoder, GenericEncoder};
use cbor_codec::value::Value;
use cbor_codec::value;
use byteorder::{WriteBytesExt, ReadBytesExt, BigEndian, ByteOrder};
use failure::ResultExt;
use std::collections::HashMap;
use std::io::Cursor;
use super::error::*;
pub enum Request<'a> {
MakeCredential(MakeCredentialRequest<'a>),
GetAssertion(GetAssertionRequest<'a>),
GetInfo,
ClientPin(ClientPinRequest<'a>),
}
impl<'a> Request<'a> {
pub fn encode<W: WriteBytesExt>(&self, writer: &mut W) -> FidoResult<()> {
let mut encoder = Encoder::new(writer);
match self {
Request::MakeCredential(req) => req.encode(&mut encoder),
Request::GetAssertion(req) => req.encode(&mut encoder),
Request::GetInfo => {
encoder
.writer()
.write_u8(0x04)
.context(FidoErrorKind::CborEncode)
.map_err(From::from)
}
Request::ClientPin(req) => req.encode(&mut encoder),
}
}
pub fn decode<R: ReadBytesExt>(&self, reader: R) -> FidoResult<Response> {
Ok(match self {
Request::MakeCredential(_) => Response::MakeCredential(
MakeCredentialResponse::decode(reader)?,
),
Request::GetAssertion(_) => Response::GetAssertion(
GetAssertionResponse::decode(reader)?,
),
Request::GetInfo => Response::GetInfo(GetInfoResponse::decode(reader)?),
Request::ClientPin(_) => Response::ClientPin(ClientPinResponse::decode(reader)?),
})
}
}
#[derive(Debug)]
pub enum Response {
MakeCredential(MakeCredentialResponse),
GetAssertion(GetAssertionResponse),
GetInfo(GetInfoResponse),
ClientPin(ClientPinResponse),
}
#[derive(Default, Debug)]
pub struct MakeCredentialRequest<'a> {
pub client_data_hash: &'a [u8],
pub rp: PublicKeyCredentialRpEntity<'a>,
pub user: PublicKeyCredentialUserEntity<'a>,
pub pub_key_cred_params: &'a [(&'a str, i32)],
pub exclude_list: &'a [PublicKeyCredentialDescriptor],
pub extensions: &'a [(&'a str, &'a Value)],
pub options: Option<AuthenticatorOptions>,
pub pin_auth: Option<[u8; 16]>,
pub pin_protocol: Option<u8>,
}
impl<'a> MakeCredentialRequest<'a> {
pub fn encode<W: WriteBytesExt>(&self, mut encoder: &mut Encoder<W>) -> FidoResult<()> {
encoder.writer().write_u8(0x01).context(
FidoErrorKind::CborEncode,
)?; // authenticatorMakeCredential
let mut length = 4;
length += !self.exclude_list.is_empty() as usize;
length += !self.extensions.is_empty() as usize;
length += self.options.is_some() as usize;
length += self.pin_auth.is_some() as usize;
length += self.pin_protocol.is_some() as usize;
encoder.object(length)?;
encoder.u8(0x01)?; // clientDataHash
encoder.bytes(&self.client_data_hash)?;
encoder.u8(0x02)?; // rp
self.rp.encode(&mut encoder)?;
encoder.u8(0x03)?; // user
self.user.encode(&mut encoder)?;
encoder.u8(0x04)?; // pubKeyCredParams
encoder.array(self.pub_key_cred_params.len())?;
for (cred_type, alg) in self.pub_key_cred_params {
encoder.object(2)?;
encoder.text("alg")?;
encoder.i32(*alg)?;
encoder.text("type")?;
encoder.text(&cred_type)?;
}
if self.exclude_list.len() > 0 {
encoder.u8(0x05)?; // excludeList
encoder.array(self.exclude_list.len())?;
for item in self.exclude_list {
item.encode(&mut encoder)?;
}
}
if self.extensions.len() > 0 {
encoder.u8(0x06)?; // extensions
encoder.object(self.extensions.len())?;
for (key, value) in self.extensions {
encoder.text(key)?;
let mut generic = GenericEncoder::new(encoder.writer());
generic.value(value)?;
}
}
if let Some(options) = &self.options {
if options.encoded() {
encoder.u8(0x07)?; // options
options.encode(&mut encoder)?;
}
}
if let Some(pin_auth) = &self.pin_auth {
encoder.u8(0x08)?; // pinAuth
encoder.bytes(pin_auth)?;
}
if let Some(pin_protocol) = &self.pin_protocol {
encoder.u8(0x09)?; // pinProtocol
encoder.u8(*pin_protocol)?;
}
Ok(())
}
}
#[derive(Debug, Default)]
pub struct MakeCredentialResponse {
pub format: String,
pub auth_data: AuthenticatorData,
}
impl MakeCredentialResponse {
pub fn decode<R: ReadBytesExt>(mut reader: R) -> FidoResult<Self> {
let status = reader.read_u8().context(FidoErrorKind::CborDecode)?;
if status != 0 {
Err(FidoErrorKind::CborError(status))?
}
let mut decoder = Decoder::new(Config::default(), reader);
let mut response = MakeCredentialResponse::default();
for _ in 0..decoder.object()? {
let key = decoder.u8()?;
match key {
0x01 => response.format = decoder.text()?,
0x02 => response.auth_data = AuthenticatorData::from_bytes(&decoder.bytes()?)?,
0x03 => break, // TODO: parse attestation
_ => continue,
}
}
Ok(response)
}
}
#[derive(Debug, Default)]
pub struct GetAssertionRequest<'a> {
pub rp_id: &'a str,
pub client_data_hash: &'a [u8],
pub allow_list: &'a [PublicKeyCredentialDescriptor],
pub extensions: &'a [(&'a str, &'a Value)],
pub options: Option<AuthenticatorOptions>,
pub pin_auth: Option<[u8; 16]>,
pub pin_protocol: Option<u8>,
}
impl<'a> GetAssertionRequest<'a> {
pub fn encode<W: WriteBytesExt>(&self, mut encoder: &mut Encoder<W>) -> FidoResult<()> {
encoder.writer().write_u8(0x02).context(
FidoErrorKind::CborEncode,
)?; // authenticatorGetAssertion
let mut length = 2;
length += !self.allow_list.is_empty() as usize;
length += !self.extensions.is_empty() as usize;
length += self.options.is_some() as usize;
length += self.pin_auth.is_some() as usize;
length += self.pin_protocol.is_some() as usize;
encoder.object(length)?;
encoder.u8(0x01)?; // rpId
encoder.text(&self.rp_id)?;
encoder.u8(0x02)?; // clientDataHash
encoder.bytes(self.client_data_hash)?;
if !self.allow_list.is_empty() {
encoder.u8(0x03)?; // allowList
encoder.array(self.allow_list.len())?;
for item in self.allow_list {
item.encode(&mut encoder)?;
}
}
if self.extensions.len() > 0 {
encoder.u8(0x04)?; // extensions
encoder.object(self.extensions.len())?;
for (key, value) in self.extensions {
encoder.text(key)?;
let mut generic = GenericEncoder::new(encoder.writer());
generic.value(value)?;
}
}
if let Some(options) = &self.options {
if options.encoded() {
encoder.u8(0x05)?; // options
options.encode(&mut encoder)?;
}
}
if let Some(pin_auth) = &self.pin_auth {
encoder.u8(0x06)?; // pinAuth
encoder.bytes(pin_auth)?;
}
if let Some(pin_protocol) = &self.pin_protocol {
encoder.u8(0x07)?; // pinProtocol
encoder.u8(*pin_protocol)?;
}
Ok(())
}
}
#[derive(Debug, Default)]
pub struct GetAssertionResponse {
pub credential: Option<PublicKeyCredentialDescriptor>,
pub auth_data_bytes: Vec<u8>,
pub auth_data: AuthenticatorData,
pub signature: Vec<u8>,
}
impl GetAssertionResponse {
pub fn decode<R: ReadBytesExt>(mut reader: R) -> FidoResult<Self> {
let status = reader.read_u8().context(FidoErrorKind::CborDecode)?;
if status != 0 {
Err(FidoErrorKind::CborError(status))?
}
let mut decoder = Decoder::new(Config::default(), reader);
let mut response = GetAssertionResponse::default();
for _ in 0..decoder.object()? {
let key = decoder.u8()?;
match key {
0x01 => {
response.credential = Some(PublicKeyCredentialDescriptor::decode(&mut decoder)?)
}
0x02 => {
response.auth_data_bytes = decoder.bytes()?;
response.auth_data = AuthenticatorData::from_bytes(&response.auth_data_bytes)?;
}
0x03 => response.signature = decoder.bytes()?,
_ => continue,
}
}
Ok(response)
}
}
#[derive(Debug, Default)]
pub struct GetInfoResponse {
pub versions: Vec<String>,
pub extensions: Vec<String>,
pub aaguid: [u8; 16],
pub options: OptionsInfo,
pub max_msg_size: u16,
pub pin_protocols: Vec<u8>,
}
impl GetInfoResponse {
pub fn decode<R: ReadBytesExt>(mut reader: R) -> FidoResult<Self> {
let status = reader.read_u8().context(FidoErrorKind::CborDecode)?;
if status != 0 {
Err(FidoErrorKind::CborError(status))?
}
let mut decoder = Decoder::new(Config::default(), reader);
let mut response = GetInfoResponse::default();
for _ in 0..decoder.object()? {
match decoder.u8()? {
0x01 => {
for _ in 0..decoder.array()? {
response.versions.push(decoder.text()?);
}
}
0x02 => {
for _ in 0..decoder.array()? {
response.extensions.push(decoder.text()?);
}
}
0x03 => response.aaguid.copy_from_slice(&decoder.bytes()?[..]),
0x04 => response.options = OptionsInfo::decode(&mut decoder)?,
0x05 => response.max_msg_size = decoder.u16()?,
0x06 => {
for _ in 0..decoder.array()? {
response.pin_protocols.push(decoder.u8()?);
}
}
_ => continue,
}
}
Ok(response)
}
}
#[derive(Debug, Default)]
pub struct ClientPinRequest<'a> {
pub pin_protocol: u8,
pub sub_command: u8,
pub key_agreement: Option<&'a CoseKey>,
pub pin_auth: Option<[u8; 16]>,
pub new_pin_enc: Option<Vec<u8>>,
pub pin_hash_enc: Option<[u8; 16]>,
}
impl<'a> ClientPinRequest<'a> {
pub fn encode<W: WriteBytesExt>(&self, encoder: &mut Encoder<W>) -> FidoResult<()> {
encoder.writer().write_u8(0x06).context(
FidoErrorKind::CborEncode,
)?; // authenticatorClientPIN
let mut length = 2;
length += self.key_agreement.is_some() as usize;
length += self.pin_auth.is_some() as usize;
length += self.new_pin_enc.is_some() as usize;
length += self.pin_hash_enc.is_some() as usize;
encoder.object(length)?;
encoder.u8(0x01)?; // pinProtocol
encoder.u8(self.pin_protocol)?;
encoder.u8(0x02)?; // subCommand
encoder.u8(self.sub_command)?;
if let Some(key_agreement) = self.key_agreement {
encoder.u8(0x03)?; // keyAgreement
key_agreement.encode(encoder)?;
}
if let Some(pin_auth) = &self.pin_auth {
encoder.u8(0x04)?; // pinAuth
encoder.bytes(pin_auth)?;
}
if let Some(new_pin_enc) = &self.new_pin_enc {
encoder.u8(0x05)?; // newPinEnc
encoder.bytes(&new_pin_enc)?;
}
if let Some(pin_hash_enc) = &self.pin_hash_enc {
encoder.u8(0x06)?; // pinHashEnc
encoder.bytes(pin_hash_enc)?;
}
Ok(())
}
}
#[derive(Debug, Default)]
pub struct ClientPinResponse {
pub key_agreement: Option<CoseKey>,
pub pin_token: Option<[u8; 16]>,
pub retries: Option<u8>,
}
impl ClientPinResponse {
pub fn decode<R: ReadBytesExt>(mut reader: R) -> FidoResult<Self> {
let status = reader.read_u8().context(FidoErrorKind::CborDecode)?;
if status != 0 {
Err(FidoErrorKind::CborError(status))?
}
let mut decoder = Decoder::new(Config::default(), reader);
let mut response = ClientPinResponse::default();
for _ in 0..decoder.object()? {
match decoder.u8()? {
0x01 => {
let mut generic = GenericDecoder::from_decoder(decoder);
response.key_agreement = Some(CoseKey::decode(&mut generic)?);
decoder = generic.into_inner();
}
0x02 => {
let mut pin_token = [0; 16];
pin_token.copy_from_slice(&decoder.bytes()?[..]);
response.pin_token = Some(pin_token)
}
0x03 => response.retries = Some(decoder.u8()?),
_ => continue,
}
}
Ok(response)
}
}
#[derive(Debug)]
pub struct OptionsInfo {
pub plat: bool,
pub rk: bool,
pub client_pin: Option<bool>,
pub up: bool,
pub uv: Option<bool>,
}
impl Default for OptionsInfo {
fn default() -> Self {
OptionsInfo {
plat: false,
rk: false,
client_pin: None,
up: true,
uv: None,
}
}
}
impl OptionsInfo {
pub fn decode<R: ReadBytesExt>(decoder: &mut Decoder<R>) -> FidoResult<Self> {
let mut options = OptionsInfo::default();
for _ in 0..decoder.object()? {
match decoder.text()?.as_ref() {
"plat" => options.plat = decoder.bool()?,
"rk" => options.rk = decoder.bool()?,
"clientPin" => options.client_pin = Some(decoder.bool()?),
"up" => options.up = decoder.bool()?,
"uv" => options.uv = Some(decoder.bool()?),
_ => continue,
}
}
Ok(options)
}
}
#[derive(Debug, Default)]
pub struct AuthenticatorData {
pub rp_id_hash: [u8; 32],
pub up: bool,
pub uv: bool,
pub sign_count: u32,
pub attested_credential_data: AttestedCredentialData,
pub extensions: HashMap<String, Value>,
}
impl AuthenticatorData {
pub fn from_bytes(bytes: &[u8]) -> FidoResult<Self> {
let mut data = AuthenticatorData::default();
data.rp_id_hash.copy_from_slice(&bytes[0..32]);
let flags = bytes[32];
data.up = (flags & 0x01) == 0x01;
data.uv = (flags & 0x02) == 0x02;
data.sign_count = BigEndian::read_u32(&bytes[33..37]);
if bytes.len() < 38 {
return Ok(data);
}
let mut cur = Cursor::new(&bytes[37..]);
let attested_credential_data = AttestedCredentialData::from_bytes(&mut cur)?;
data.attested_credential_data = attested_credential_data;
if cur.position() >= (bytes.len() - 37) as u64 {
return Ok(data);
}
let mut decoder = GenericDecoder::new(Config::default(), cur);
for _ in 0..decoder.borrow_mut().object()? {
let key = decoder.borrow_mut().text()?;
let value = decoder.value()?;
data.extensions.insert(key.to_string(), value);
}
Ok(data)
}
}
#[derive(Debug, Default)]
pub struct AttestedCredentialData {
pub aaguid: [u8; 16],
pub credential_id: Vec<u8>,
pub credential_public_key: CoseKey,
}
impl AttestedCredentialData {
pub fn from_bytes(cur: &mut Cursor<&[u8]>) -> FidoResult<Self> {
let mut response = AttestedCredentialData::default();
let bytes = cur.get_ref();
if bytes.is_empty() {
return Ok(response);
}
response.aaguid.copy_from_slice(&bytes[0..16]);
let id_length = BigEndian::read_u16(&bytes[16..18]) as usize;
response.credential_id = Vec::from(&bytes[18..(18 + id_length)]);
cur.set_position(18 + id_length as u64);
let mut decoder = GenericDecoder::new(Config::default(), cur);
response.credential_public_key = CoseKey::decode(&mut decoder)?;
Ok(response)
}
}
#[derive(Debug, Default)]
pub struct P256Key {
x: [u8; 32],
y: [u8; 32],
}
impl P256Key {
pub fn from_cose(cose: &CoseKey) -> FidoResult<Self> {
if cose.key_type != 2 || cose.algorithm != -7 {
Err(FidoErrorKind::KeyType)?
}
if let (Some(Value::U8(curve)),
Some(Value::Bytes(value::Bytes::Bytes(x))),
Some(Value::Bytes(value::Bytes::Bytes(y)))) =
(
cose.parameters.get(&-1),
cose.parameters.get(&-2),
cose.parameters.get(&-3),
)
{
if *curve != 1 {
Err(FidoErrorKind::KeyType)?
}
let mut key = P256Key::default();
key.x.copy_from_slice(&x);
key.y.copy_from_slice(&y);
return Ok(key);
}
Err(FidoErrorKind::KeyType)?
}
pub fn from_bytes(bytes: &[u8]) -> FidoResult<Self> {
if bytes.len() != 65 || bytes[0] != 0x04 {
Err(FidoErrorKind::CborDecode)?
}
let mut res = P256Key::default();
res.x.copy_from_slice(&bytes[1..33]);
res.y.copy_from_slice(&bytes[33..65]);
Ok(res)
}
pub fn to_cose(&self) -> CoseKey {
CoseKey {
key_type: 2,
algorithm: -7,
parameters: [
(-1, Value::U8(1)),
(-2, Value::Bytes(value::Bytes::Bytes(self.x.to_vec()))),
(-3, Value::Bytes(value::Bytes::Bytes(self.y.to_vec()))),
].iter()
.cloned()
.collect(),
}
}
pub fn bytes(&self) -> [u8; 65] {
let mut bytes = [0; 65];
bytes[0] = 0x04;
bytes[1..33].copy_from_slice(&self.x);
bytes[33..65].copy_from_slice(&self.y);
bytes
}
}
#[derive(Debug, Default)]
pub struct CoseKey {
key_type: u16,
algorithm: i32,
parameters: HashMap<i16, Value>,
}
impl CoseKey {
pub fn encode<W: WriteBytesExt>(&self, encoder: &mut Encoder<W>) -> FidoResult<()> {
let size = 1 + self.parameters.len();
encoder.object(size)?;
encoder.i16(0x01)?; // keyType
encoder.u16(self.key_type)?;
//encoder.i16(0x02)?; // algorithm
//encoder.i32(self.algorithm)?;
for (key, value) in self.parameters.iter() {
encoder.i16(*key)?;
let mut generic = GenericEncoder::new(encoder.writer());
generic.value(value)?;
}
Ok(())
}
pub fn decode<R: ReadBytesExt>(generic: &mut GenericDecoder<R>) -> FidoResult<Self> {
let items;
{
let decoder = generic.borrow_mut();
items = decoder.object()?;
}
let mut cose_key = CoseKey::default();
cose_key.algorithm = -7;
for _ in 0..items {
match generic.borrow_mut().i16()? {
0x01 => cose_key.key_type = generic.borrow_mut().u16()?,
0x02 => cose_key.algorithm = generic.borrow_mut().i32()?,
key if key < 0 => {
cose_key.parameters.insert(key, generic.value()?);
}
_ => {
generic.value()?; // skip unknown parameter
}
}
}
Ok(cose_key)
}
}
#[derive(Debug, Default)]
pub struct PublicKeyCredentialRpEntity<'a> {
pub id: &'a str,
pub name: Option<&'a str>,
pub icon: Option<&'a str>,
}
impl<'a> PublicKeyCredentialRpEntity<'a> {
pub fn encode<W: WriteBytesExt>(&self, encoder: &mut Encoder<W>) -> FidoResult<()> {
let mut length = 1;
length += self.name.is_some() as usize;
length += self.icon.is_some() as usize;
encoder.object(length)?;
encoder.text("id")?;
encoder.text(&self.id)?;
if let Some(icon) = &self.icon {
encoder.text("icon")?;
encoder.text(&icon)?;
}
if let Some(name) = &self.name {
encoder.text("name")?;
encoder.text(&name)?;
}
Ok(())
}
}
#[derive(Debug, Default)]
pub struct PublicKeyCredentialUserEntity<'a> {
pub id: &'a [u8],
pub name: &'a str,
pub icon: Option<&'a str>,
pub display_name: Option<&'a str>,
}
impl<'a> PublicKeyCredentialUserEntity<'a> {
pub fn encode<W: WriteBytesExt>(&self, encoder: &mut Encoder<W>) -> FidoResult<()> {
let mut length = 2;
length += self.icon.is_some() as usize;
length += self.display_name.is_some() as usize;
encoder.object(length)?;
encoder.text("id")?;
encoder.bytes(&self.id)?;
if let Some(icon) = &self.icon {
encoder.text("icon")?;
encoder.text(&icon)?;
}
encoder.text("name")?;
encoder.text(&self.name)?;
if let Some(display_name) = &self.display_name {
encoder.text("displayName")?;
encoder.text(&display_name)?;
}
Ok(())
}
}
#[derive(Debug, Default)]
pub struct PublicKeyCredentialDescriptor {
pub cred_type: String,
pub id: Vec<u8>,
}
impl PublicKeyCredentialDescriptor {
pub fn decode<R: ReadBytesExt>(decoder: &mut Decoder<R>) -> FidoResult<Self> {
let mut response = PublicKeyCredentialDescriptor::default();
for _ in 0..decoder.object()? {
match decoder.text()?.as_ref() {
"id" => response.id = decoder.bytes()?,
"type" => response.cred_type = decoder.text()?,
_ => continue,
}
}
Ok(response)
}
pub fn encode<W: WriteBytesExt>(&self, encoder: &mut Encoder<W>) -> FidoResult<()> {
encoder.object(2)?;
encoder.text("id")?;
encoder.bytes(&self.id)?;
encoder.text("type")?;
encoder.text(&self.cred_type)?;
Ok(())
}
}
#[derive(Debug)]
pub struct AuthenticatorOptions {
pub rk: bool,
pub uv: bool,
}
impl AuthenticatorOptions {
pub fn encoded(&self) -> bool {
self.rk || self.uv
}
pub fn encode<W: WriteBytesExt>(&self, encoder: &mut Encoder<W>) -> FidoResult<()> {
let length = (self.rk as usize) + (self.uv as usize);
encoder.object(length)?;
if self.rk {
encoder.text("rk")?;
encoder.bool(true)?;
}
if self.uv {
encoder.text("uv")?;
encoder.bool(true)?;
}
Ok(())
}
}

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// 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 ring::{agreement, rand, digest, hmac, signature};
use ring::error::Unspecified;
use untrusted::Input;
use rust_crypto::blockmodes::NoPadding;
use rust_crypto::aes;
use rust_crypto::buffer::{RefReadBuffer, RefWriteBuffer};
use failure::ResultExt;
use super::cbor::{CoseKey, P256Key};
use super::error::*;
#[derive(Debug)]
pub struct SharedSecret {
pub public_key: CoseKey,
pub shared_secret: [u8; 32],
}
impl SharedSecret {
pub fn new(peer_key: &CoseKey) -> FidoResult<Self> {
let rng = rand::SystemRandom::new();
let private = agreement::EphemeralPrivateKey::generate(&agreement::ECDH_P256, &rng)
.context(FidoErrorKind::GenerateKey)?;
let public = &mut [0u8; agreement::PUBLIC_KEY_MAX_LEN][..private.public_key_len()];
private.compute_public_key(public).context(
FidoErrorKind::GenerateKey,
)?;
let peer = P256Key::from_cose(peer_key)
.context(FidoErrorKind::ParsePublic)?
.bytes();
let peer = Input::from(&peer);
let shared_secret = agreement::agree_ephemeral(
private,
&agreement::ECDH_P256,
peer,
Unspecified,
|material| Ok(digest::digest(&digest::SHA256, material)),
).context(FidoErrorKind::GenerateSecret)?;
let mut res = SharedSecret {
public_key: P256Key::from_bytes(&public)
.context(FidoErrorKind::ParsePublic)?
.to_cose(),
shared_secret: [0; 32],
};
res.shared_secret.copy_from_slice(shared_secret.as_ref());
Ok(res)
}
pub fn encrypt_pin(&self, pin: &str) -> FidoResult<[u8; 16]> {
let mut encryptor = aes::cbc_encryptor(
aes::KeySize::KeySize256,
&self.shared_secret,
&[0u8; 16],
NoPadding,
);
let pin_bytes = pin.as_bytes();
let hash = digest::digest(&digest::SHA256, &pin_bytes);
let in_bytes = &hash.as_ref()[0..16];
let mut input = RefReadBuffer::new(&in_bytes);
let mut out_bytes = [0; 16];
let mut output = RefWriteBuffer::new(&mut out_bytes);
encryptor.encrypt(&mut input, &mut output, true).map_err(
|_| {
FidoErrorKind::EncryptPin
},
)?;
Ok(out_bytes)
}
pub fn decrypt_token(&self, data: &mut [u8]) -> FidoResult<PinToken> {
let mut decryptor = aes::cbc_decryptor(
aes::KeySize::KeySize256,
&self.shared_secret,
&[0u8; 16],
NoPadding,
);
let mut input = RefReadBuffer::new(data);
let mut out_bytes = [0; 16];
let mut output = RefWriteBuffer::new(&mut out_bytes);
decryptor.decrypt(&mut input, &mut output, true).map_err(
|_| {
FidoErrorKind::DecryptPin
},
)?;
Ok(PinToken(hmac::SigningKey::new(&digest::SHA256, &out_bytes)))
}
}
pub struct PinToken(hmac::SigningKey);
impl PinToken {
pub fn auth(&self, data: &[u8]) -> [u8; 16] {
let signature = hmac::sign(&self.0, &data);
let mut out = [0; 16];
out.copy_from_slice(&signature.as_ref()[0..16]);
out
}
}
pub fn verify_signature(
public_key: &[u8],
client_data: &[u8],
auth_data: &[u8],
signature: &[u8],
) -> bool {
let public_key = Input::from(&public_key);
let msg_len = client_data.len() + auth_data.len();
let mut msg = Vec::with_capacity(msg_len);
msg.extend_from_slice(auth_data);
msg.extend_from_slice(client_data);
let msg = Input::from(&msg);
let signature = Input::from(signature);
signature::verify(
&signature::ECDSA_P256_SHA256_ASN1,
public_key,
msg,
signature,
).is_ok()
}

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// 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 cbor_codec::{EncodeError, DecodeError};
use std::fmt;
use std::fmt::Display;
use failure::{Context, Backtrace, Fail};
pub type FidoResult<T> = Result<T, FidoError>;
#[derive(Debug)]
pub struct FidoError(Context<FidoErrorKind>);
#[derive(Copy, Clone, Eq, PartialEq, Debug, Fail)]
pub enum FidoErrorKind {
#[fail(display = "Read/write error with device.")]
Io,
#[fail(display = "Error while reading packet from device.")]
ReadPacket,
#[fail(display = "Error while writing packet to device.")]
WritePacket,
#[fail(display = "Error while parsing CTAP from device.")]
ParseCtap,
#[fail(display = "Error while encoding CBOR for device.")]
CborEncode,
#[fail(display = "Error while decoding CBOR from device.")]
CborDecode,
#[fail(display = "Packets received from device in the wrong order.")]
InvalidSequence,
#[fail(display = "Failed to generate private keypair.")]
GenerateKey,
#[fail(display = "Failed to generate shared secret.")]
GenerateSecret,
#[fail(display = "Failed to parse public key.")]
ParsePublic,
#[fail(display = "Failed to encrypt PIN.")]
EncryptPin,
#[fail(display = "Failed to decrypt PIN.")]
DecryptPin,
#[fail(display = "Supplied key has incorrect type.")]
KeyType,
#[fail(display = "Device returned error: 0x{:x}", _0)]
CborError(u8),
#[fail(display = "Device does not support FIDO2")]
DeviceUnsupported,
#[fail(display = "This operating requires a PIN but none was provided.")]
PinRequired,
}
impl Fail for FidoError {
fn cause(&self) -> Option<&Fail> {
self.0.cause()
}
fn backtrace(&self) -> Option<&Backtrace> {
self.0.backtrace()
}
}
impl Display for FidoError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
Display::fmt(&self.0, f)
}
}
impl FidoError {
pub fn kind(&self) -> FidoErrorKind {
*self.0.get_context()
}
}
impl From<FidoErrorKind> for FidoError {
#[inline(always)]
fn from(kind: FidoErrorKind) -> FidoError {
FidoError(Context::new(kind))
}
}
impl From<Context<FidoErrorKind>> for FidoError {
fn from(inner: Context<FidoErrorKind>) -> FidoError {
FidoError(inner)
}
}
impl From<EncodeError> for FidoError {
#[inline(always)]
fn from(err: EncodeError) -> FidoError {
FidoError(err.context(FidoErrorKind::CborEncode))
}
}
impl From<DecodeError> for FidoError {
#[inline(always)]
fn from(err: DecodeError) -> FidoError {
FidoError(err.context(FidoErrorKind::CborDecode))
}
}

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// 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 std::path::PathBuf;
#[derive(Debug, Clone)]
/// Storage for device related information
pub struct DeviceInfo {
pub path: PathBuf,
pub usage_page: u16,
pub usage: u16,
}

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// 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 std::io;
use std::fs;
use std::path::PathBuf;
use byteorder::{ByteOrder, LittleEndian};
pub use super::hid_common::*;
static REPORT_DESCRIPTOR_KEY_MASK: u8 = 0xfc;
static LONG_ITEM_ENCODING: u8 = 0xfe;
static USAGE_PAGE: u8 = 0x04;
static USAGE: u8 = 0x08;
static REPORT_SIZE: u8 = 0x74;
pub fn enumerate() -> io::Result<Vec<DeviceInfo>> {
fs::read_dir("/sys/class/hidraw")?
.filter_map(|entry| entry.ok())
.map(|entry| path_to_device(&entry.path()))
.collect()
}
fn path_to_device(path: &PathBuf) -> io::Result<DeviceInfo> {
let mut rd_path = path.clone();
rd_path.push("device/report_descriptor");
let rd = fs::read(rd_path)?;
let mut usage_page: u16 = 0;
let mut usage: u16 = 0;
let mut report_size: u16 = 0;
let mut pos: usize = 0;
while pos < rd.len() {
let key = rd[pos];
let mut key_size: usize = 1;
let mut size: u8;
if key == LONG_ITEM_ENCODING {
key_size = 3;
size = rd[pos + 1];
} else {
size = key & 0x03;
if size == 0x03 {
size = 0x04
}
}
if key & REPORT_DESCRIPTOR_KEY_MASK == USAGE_PAGE {
if size != 2 {
usage_page = u16::from(rd[pos + 1])
} else {
usage_page = LittleEndian::read_u16(&rd[(pos + 1)..(pos + 1 + (size as usize))]);
}
}
if key & REPORT_DESCRIPTOR_KEY_MASK == USAGE {
if size != 2 {
usage = u16::from(rd[pos + 1])
} else {
usage = LittleEndian::read_u16(&rd[(pos + 1)..(pos + 1 + (size as usize))]);
}
}
if key & REPORT_DESCRIPTOR_KEY_MASK == REPORT_SIZE {
if size != 2 {
report_size = u16::from(rd[pos + 1])
} else {
report_size = LittleEndian::read_u16(&rd[(pos + 1)..(pos + 1 + (size as usize))]);
}
}
pos = pos + key_size + size as usize;
}
let mut device_path = PathBuf::from("/dev");
device_path.push(path.file_name().unwrap());
Ok(DeviceInfo {
path: device_path,
usage_page,
usage,
})
}

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// 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.
//! An implementation of the CTAP2 protocol over USB.
//!
//! # Example
//!
//! ```
//! # fn do_fido() -> ctap::FidoResult<()> {
//! let devices = ctap::get_devices()?;
//! let device_info = &devices[0];
//! let mut device = ctap::FidoDevice::new(device_info)?;
//!
//! // This can be omitted if the FIDO device is not configured with a PIN.
//! let pin = "test";
//! device.unlock(pin)?;
//!
//! // In a real application these values would come from the requesting app.
//! let rp_id = "rp_id";
//! let user_id = [0];
//! let user_name = "user_name";
//! let client_data_hash = [0; 32];
//! let cred = device.make_credential(
//! rp_id,
//! &user_id,
//! user_name,
//! &client_data_hash
//! )?;
//!
//! // In a real application the credential would be stored and used later.
//! let result = device.get_assertion(&cred, &client_data_hash);
//! # Ok(())
//! # }
#![allow(dead_code)]
extern crate rand;
extern crate failure;
#[macro_use]
extern crate failure_derive;
#[macro_use]
extern crate num_derive;
extern crate num_traits;
extern crate byteorder;
extern crate cbor as cbor_codec;
extern crate ring;
extern crate untrusted;
extern crate crypto as rust_crypto;
mod packet;
mod hid_common;
mod hid_linux;
mod error;
mod crypto;
mod cbor;
use std::cmp;
use std::u8;
use std::u16;
use std::fs;
use std::io::{Read, Write, Cursor};
use failure::{Fail, ResultExt};
use rand::prelude::*;
use num_traits::FromPrimitive;
use self::hid_linux as hid;
use self::packet::CtapCommand;
use self::packet::Packet;
pub use self::error::*;
static BROADCAST_CID: [u8; 4] = [0xff, 0xff, 0xff, 0xff];
/// Looks for any connected HID devices and returns those that support FIDO.
pub fn get_devices() -> error::FidoResult<Vec<hid::DeviceInfo>> {
Ok(
hid::enumerate()
.context(FidoErrorKind::Io)?
.into_iter()
.filter(|dev| dev.usage_page == 0xf1d0 && dev.usage == 0x21)
.collect(),
)
}
/// A credential created by a FIDO2 authenticator.
#[derive(Debug)]
pub struct FidoCredential {
/// The ID provided by the authenticator.
pub id: Vec<u8>,
/// The public key provided by the authenticator, in uncompressed form.
pub public_key: Vec<u8>,
/// The Relying Party ID provided by the platform when this key was generated.
pub rp_id: String,
}
/// An opened FIDO authenticator.
pub struct FidoDevice {
device: fs::File,
packet_size: u16,
channel_id: [u8; 4],
needs_pin: bool,
shared_secret: Option<crypto::SharedSecret>,
pin_token: Option<crypto::PinToken>,
}
impl FidoDevice {
/// Open and initialize a given device. DeviceInfo is provided by the `get_devices`
/// function. This method will allocate a channel for this application, verify that
/// it supports FIDO2, and checks if a PIN is set.
///
/// This method will fail if the device can't be opened, if the device returns
/// malformed data or if the device is not supported.
pub fn new(device: &hid::DeviceInfo) -> error::FidoResult<Self> {
let mut options = fs::OpenOptions::new();
options.read(true).write(true);
let mut dev = FidoDevice {
device: options.open(&device.path).context(FidoErrorKind::Io)?,
packet_size: 64,
channel_id: BROADCAST_CID,
needs_pin: false,
shared_secret: None,
pin_token: None,
};
dev.init()?;
Ok(dev)
}
fn init(&mut self) -> FidoResult<()> {
let mut nonce = [0u8; 8];
thread_rng().fill_bytes(&mut nonce);
let response = self.exchange(CtapCommand::Init, &nonce)?;
if response.len() < 17 || response[0..8] != nonce {
Err(FidoErrorKind::ParseCtap)?
}
self.channel_id.copy_from_slice(&response[8..12]);
let response = match self.cbor(cbor::Request::GetInfo)? {
cbor::Response::GetInfo(resp) => resp,
_ => Err(FidoErrorKind::CborDecode)?,
};
if !response.versions.iter().any(|ver| ver == "FIDO_2_0") {
Err(FidoErrorKind::DeviceUnsupported)?
}
if !response.pin_protocols.iter().any(|ver| *ver == 1) {
Err(FidoErrorKind::DeviceUnsupported)?
}
self.needs_pin = response.options.client_pin == Some(true);
Ok(())
}
fn init_shared_secret(&mut self) -> FidoResult<()> {
let mut request = cbor::ClientPinRequest::default();
request.pin_protocol = 1;
request.sub_command = 0x02; // getKeyAgreement
let response = match self.cbor(cbor::Request::ClientPin(request))? {
cbor::Response::ClientPin(resp) => resp,
_ => Err(FidoErrorKind::CborDecode)?,
};
if let Some(key_agreement) = response.key_agreement {
self.shared_secret = Some(crypto::SharedSecret::new(&key_agreement)?);
Ok(())
} else {
Err(FidoErrorKind::CborDecode)?
}
}
/// Unlock the device with the provided PIN. Internally this will generate
/// an ECDH keypair, send the encrypted PIN to the device and store the PIN
/// token that the device generates on every power cycle. The PIN itself is
/// not stored.
///
/// This method will fail if the device returns malformed data or the PIN is
/// incorrect.
pub fn unlock(&mut self, pin: &str) -> FidoResult<()> {
while self.shared_secret.is_none() {
self.init_shared_secret()?;
}
// If the PIN is invalid the device should create a new agreementKey,
// so we only replace shared_secret on success.
let shared_secret = self.shared_secret.take().unwrap();
let mut request = cbor::ClientPinRequest::default();
request.pin_protocol = 1;
request.sub_command = 0x05; // getPINToken
request.key_agreement = Some(&shared_secret.public_key);
request.pin_hash_enc = Some(shared_secret.encrypt_pin(pin)?);
let response = match self.cbor(cbor::Request::ClientPin(request))? {
cbor::Response::ClientPin(resp) => resp,
_ => Err(FidoErrorKind::CborDecode)?,
};
if let Some(mut pin_token) = response.pin_token {
self.pin_token = Some(shared_secret.decrypt_token(&mut pin_token)?);
self.shared_secret = Some(shared_secret);
Ok(())
} else {
Err(FidoErrorKind::CborDecode)?
}
}
/// Request a new credential from the authenticator. The `rp_id` should be
/// a stable string used to identify the party for whom the credential is
/// created, for convenience it will be returned with the credential.
/// `user_id` and `user_name` are not required when requesting attestations
/// but they MAY be displayed to the user and MAY be stored on the device
/// to be returned with an attestation if the device supports this.
/// `client_data_hash` SHOULD be a SHA256 hash of provided `client_data`,
/// this is only used to verify the attestation provided by the
/// authenticator. When not implementing WebAuthN this can be any random
/// 32-byte array.
///
/// This method will fail if a PIN is required but the device is not
/// unlocked or if the device returns malformed data.
pub fn make_credential(
&mut self,
rp_id: &str,
user_id: &[u8],
user_name: &str,
client_data_hash: &[u8],
) -> FidoResult<FidoCredential> {
if self.needs_pin && self.pin_token.is_none() {
Err(FidoErrorKind::PinRequired)?
}
if client_data_hash.len() != 32 {
Err(FidoErrorKind::CborEncode)?
}
let pin_auth = self.pin_token.as_ref().map(
|token| token.auth(&client_data_hash),
);
let rp = cbor::PublicKeyCredentialRpEntity {
id: rp_id,
name: None,
icon: None,
};
let user = cbor::PublicKeyCredentialUserEntity {
id: user_id,
name: user_name,
icon: None,
display_name: None,
};
let pub_key_cred_params = [("public-key", -7)];
let request = cbor::MakeCredentialRequest {
client_data_hash,
rp,
user,
pub_key_cred_params: &pub_key_cred_params,
exclude_list: Default::default(),
extensions: Default::default(),
options: Some(cbor::AuthenticatorOptions {
rk: false,
uv: true,
}),
pin_auth,
pin_protocol: pin_auth.and(Some(0x01)),
};
let response = match self.cbor(cbor::Request::MakeCredential(request))? {
cbor::Response::MakeCredential(resp) => resp,
_ => Err(FidoErrorKind::CborDecode)?,
};
let public_key = cbor::P256Key::from_cose(
&response
.auth_data
.attested_credential_data
.credential_public_key,
)?
.bytes();
Ok(FidoCredential {
id: response.auth_data.attested_credential_data.credential_id,
rp_id: String::from(rp_id),
public_key: Vec::from(&public_key[..]),
})
}
/// Request an assertion from the authenticator for a given credential.
/// `client_data_hash` SHOULD be a SHA256 hash of provided `client_data`,
/// this is signed and verified as part of the attestation. When not
/// implementing WebAuthN this can be any random 32-byte array.
///
/// This method will return whether the assertion matches the credential
/// provided, and will fail if a PIN is required but not provided or if the
/// device returns malformed data.
pub fn get_assertion(
&mut self,
credential: &FidoCredential,
client_data_hash: &[u8],
) -> FidoResult<bool> {
if self.needs_pin && self.pin_token.is_none() {
Err(FidoErrorKind::PinRequired)?
}
if client_data_hash.len() != 32 {
Err(FidoErrorKind::CborEncode)?
}
let pin_auth = self.pin_token.as_ref().map(
|token| token.auth(&client_data_hash),
);
let allow_list = [
cbor::PublicKeyCredentialDescriptor {
cred_type: String::from("public-key"),
id: credential.id.clone(),
},
];
let request = cbor::GetAssertionRequest {
rp_id: &credential.rp_id,
client_data_hash: client_data_hash,
allow_list: &allow_list,
extensions: Default::default(),
options: Some(cbor::AuthenticatorOptions {
rk: false,
uv: true,
}),
pin_auth,
pin_protocol: pin_auth.and(Some(0x01)),
};
let response = match self.cbor(cbor::Request::GetAssertion(request))? {
cbor::Response::GetAssertion(resp) => resp,
_ => Err(FidoErrorKind::CborDecode)?,
};
Ok(crypto::verify_signature(
&credential.public_key,
&client_data_hash,
&response.auth_data_bytes,
&response.signature,
))
}
fn cbor(&mut self, request: cbor::Request) -> FidoResult<cbor::Response> {
let mut buf = Cursor::new(Vec::new());
request.encode(&mut buf).context(FidoErrorKind::CborEncode)?;
let response = self.exchange(CtapCommand::Cbor, &buf.into_inner())?;
request
.decode(Cursor::new(response))
.context(FidoErrorKind::CborDecode)
.map_err(From::from)
}
fn exchange(&mut self, cmd: CtapCommand, payload: &[u8]) -> FidoResult<Vec<u8>> {
self.send(&cmd, payload)?;
self.receive(&cmd)
}
fn send(&mut self, cmd: &CtapCommand, payload: &[u8]) -> FidoResult<()> {
if payload.is_empty() || payload.len() > u16::MAX as usize {
Err(FidoErrorKind::WritePacket)?
}
let to_send = payload.len() as u16;
let max_payload = (self.packet_size - 7) as usize;
let (frame, payload) = payload.split_at(cmp::min(payload.len(), max_payload));
{
let packet = packet::InitPacket::new(&self.channel_id, cmd, to_send, frame);
self.device.write(packet.to_wire_format()).context(
FidoErrorKind::WritePacket,
)?;
}
if payload.is_empty() {
return Ok(());
}
let max_payload = (self.packet_size - 5) as usize;
for (seq, frame) in (0..u8::MAX).zip(payload.chunks(max_payload)) {
let packet = packet::ContPacket::new(&self.channel_id, seq, frame);
self.device.write(packet.to_wire_format()).context(
FidoErrorKind::WritePacket,
)?;
}
self.device.flush().context(FidoErrorKind::WritePacket)?;
Ok(())
}
fn receive(&mut self, cmd: &CtapCommand) -> FidoResult<Vec<u8>> {
let mut first_packet: Option<packet::InitPacket> = None;
let mut packet_size = 0;
while first_packet.is_none() {
let mut buf = [0; 64];
packet_size = self.device.read(&mut buf).context(
FidoErrorKind::ReadPacket,
)?;
let packet = packet::InitPacket::from_wire_format(&buf[0..packet_size]);
if packet.cmd() == CtapCommand::Error {
Err(
packet::CtapError::from_u8(packet.payload()[0])
.unwrap_or(packet::CtapError::Other)
.context(FidoErrorKind::ParseCtap),
)?
}
if packet.cid() == self.channel_id && &packet.cmd() == cmd {
first_packet = Some(packet);
}
}
let first_packet = first_packet.unwrap();
let mut data = first_packet.payload()[0..(packet_size - 7)].to_vec();
let mut to_read = (first_packet.size() as isize) - data.len() as isize;
let mut seq = 0;
while to_read > 0 {
let mut buf = [0; 64];
let packet_size = self.device.read(&mut buf).context(
FidoErrorKind::ReadPacket,
)?;
let packet = packet::ContPacket::from_wire_format(&buf[0..packet_size]);
if packet.cid() != self.channel_id {
continue;
}
if packet.seq() != seq {
Err(FidoErrorKind::InvalidSequence)?
}
let payload_size = packet_size - 5;
to_read -= payload_size as isize;
data.extend(&packet.payload()[0..payload_size]);
seq += 1;
}
Ok(data)
}
}

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// 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
}
}