fix: tolerate newer versions

improved error messages
fixed cbor issues
added hmac example

Cargo.toml

@@ -1,12 +1,13 @@
 [package]
-name = "ctap"
+name = "ctap_hmac"
-description = "A Rust implementation of the FIDO2 CTAP protocol"
+description = "A Rust implementation of the FIDO2 CTAP protocol, including the HMAC extension"
-version = "0.1.0"
+version = "0.4.5"
 license = "Apache-2.0/MIT"
-homepage = "https://github.com/ArdaXi/ctap"
+homepage = "https://github.com/shimunn/ctap"
-repository = "https://github.com/ArdaXi/ctap"
+repository = "https://github.com/shimunn/ctap"
-authors = ["Arda Xi <arda@ardaxi.com>"]
+authors = ["Arda Xi <arda@ardaxi.com>", "shimun <shimun@shimun.net>"]
 edition = "2018"
+readme = "README.md"
 
 [dependencies]
 rand = "0.6"
@@ -19,3 +20,16 @@ cbor-codec = "0.7"
 ring = "0.13"
 untrusted = "0.6"
 rust-crypto = "0.2"
+derive_builder = "0.9.0"
+crossbeam = { version = "0.7.3", optional = true }
+[dev-dependencies]
+crossbeam = "0.7.3"
+hex = "0.4.0"
+[build-dependencies]
+csv = "1.1.3"
+serde = "1.0.106"
+serde_derive = "1.0.106"
+
+
+[features]
+request_multiple = ["crossbeam"]

README.md

@@ -13,28 +13,28 @@ ctap is a library implementing the [FIDO2 CTAP](https://fidoalliance.org/specs/f
 ## Usage example
 
 ```rust
-let devices = ctap::get_devices()?;
+use ctap_hmac::*;
-let device_info = &devices[0];
+let device_info = get_devices()?.next().expect("no device connected");
-let mut device = ctap::FidoDevice::new(device_info)?;
+let mut device = 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 cred_request = FidoCredentialRequestBuilder::default()
-let user_id = [0];
+                    .rp_id("rp_id")
-let user_name = "user_name";
+                    .user_name("user_name")
-let client_data_hash = [0; 32];
+                    .build().unwrap();
-let cred = device.make_credential(
-    rp_id,
-    &user_id,
-    user_name,
-    &client_data_hash
-)?;
 
+let cred = device.make_credential(&cred_request)?;
+let cred = &&cred;
+let assertion_request = FidoAssertionRequestBuilder::default()
+                            .rp_id("rp_id")
+                            .credential(&&cred)
+                            .build().unwrap();
 // In a real application the credential would be stored and used later.
-let result = device.get_assertion(&cred, &client_data_hash);
+let result = device.get_assertion(&assertion_request);
 ```
 
 ## Limitations

build.rs

@@ -0,0 +1,41 @@
+use csv::{Reader, StringRecord};
+use serde_derive::Deserialize;
+use std::env;
+use std::fs::File;
+use std::io::{Result, Write};
+use std::iter::FromIterator;
+use std::string::String;
+
+fn main() {
+    parse_error_codes().expect("Failed to parse error codes")
+}
+
+fn parse_error_codes() -> Result<()> {
+    println!("cargo:rerun-if-changed=ctap_error_codes.csv");
+    let mut out_file = File::create(format!(
+        "{}/ctap_error_codes.rs",
+        env::var("OUT_DIR").unwrap()
+    ))?;
+    out_file.write_all(b"static CTAP_ERROR_CODES: &[(usize, &str, &str)] = &[")?;
+    let mut rdr = Reader::from_path("ctap_error_codes.csv")?;
+    rdr.set_headers(StringRecord::from_iter(&["code", "name", "desc"]));
+    #[derive(Debug, Deserialize)]
+    struct ErrorCode {
+        code: String,
+        name: String,
+        desc: String,
+    }
+    for result in rdr.deserialize() {
+        let record: ErrorCode = result.unwrap();
+        out_file.write_all(
+            format!(
+                "({}, \"{}\", \"{}\"),\n",
+                i64::from_str_radix(&record.code[2..], 16).unwrap(),
+                record.name,
+                record.desc
+            )
+            .as_bytes(),
+        )?;
+    }
+    out_file.write_all(b"];")
+}

ctap_error_codes.csv

@@ -0,0 +1,49 @@
+Code,Name,Description
+0x00,"CTAP1_ERR_SUCCESS, CTAP2_OK",Indicates successful response.
+0x01,CTAP1_ERR_INVALID_COMMAND,The command is not a valid CTAP command.
+0x02,CTAP1_ERR_INVALID_PARAMETER,The command included an invalid parameter.
+0x03,CTAP1_ERR_INVALID_LENGTH,Invalid message or item length.
+0x04,CTAP1_ERR_INVALID_SEQ,Invalid message sequencing.
+0x05,CTAP1_ERR_TIMEOUT,Message timed out.
+0x06,CTAP1_ERR_CHANNEL_BUSY,Channel busy.
+0x0A,CTAP1_ERR_LOCK_REQUIRED,Command requires channel lock.
+0x0B,CTAP1_ERR_INVALID_CHANNEL,Command not allowed on this cid.
+0x11,CTAP2_ERR_CBOR_UNEXPECTED_TYPE,Invalid/unexpected CBOR error.
+0x12,CTAP2_ERR_INVALID_CBOR,Error when parsing CBOR.
+0x14,CTAP2_ERR_MISSING_PARAMETER,Missing non-optional parameter.
+0x15,CTAP2_ERR_LIMIT_EXCEEDED,Limit for number of items exceeded.
+0x16,CTAP2_ERR_UNSUPPORTED_EXTENSION,Unsupported extension.
+0x19,CTAP2_ERR_CREDENTIAL_EXCLUDED,Valid credential found in the exclude list.
+0x21,CTAP2_ERR_PROCESSING,Processing (Lengthy operation is in progress).
+0x22,CTAP2_ERR_INVALID_CREDENTIAL,Credential not valid for the authenticator.
+0x23,CTAP2_ERR_USER_ACTION_PENDING,Authentication is waiting for user interaction.
+0x24,CTAP2_ERR_OPERATION_PENDING,"Processing, lengthy operation is in progress."
+0x25,CTAP2_ERR_NO_OPERATIONS,No request is pending.
+0x26,CTAP2_ERR_UNSUPPORTED_ALGORITHM,Authenticator does not support requested algorithm.
+0x27,CTAP2_ERR_OPERATION_DENIED,Not authorized for requested operation.
+0x28,CTAP2_ERR_KEY_STORE_FULL,Internal key storage is full.
+0x29,CTAP2_ERR_NOT_BUSY,Authenticator cannot cancel as it is not busy.
+0x2A,CTAP2_ERR_NO_OPERATION_PENDING,No outstanding operations.
+0x2B,CTAP2_ERR_UNSUPPORTED_OPTION,Unsupported option.
+0x2C,CTAP2_ERR_INVALID_OPTION,Not a valid option for current operation.
+0x2D,CTAP2_ERR_KEEPALIVE_CANCEL,Pending keep alive was cancelled.
+0x2E,CTAP2_ERR_NO_CREDENTIALS,No valid credentials provided.
+0x2F,CTAP2_ERR_USER_ACTION_TIMEOUT,Timeout waiting for user interaction.
+0x30,CTAP2_ERR_NOT_ALLOWED,"Continuation command, such as, authenticatorGetNextAssertion not allowed."
+0x31,CTAP2_ERR_PIN_INVALID,PIN Invalid.
+0x32,CTAP2_ERR_PIN_BLOCKED,PIN Blocked.
+0x33,CTAP2_ERR_PIN_AUTH_INVALID,"PIN authentication, pinAuth, verification failed."
+0x34,CTAP2_ERR_PIN_AUTH_BLOCKED,"PIN authentication,pinAuth, blocked. Requires power recycle to reset."
+0x35,CTAP2_ERR_PIN_NOT_SET,No PIN has been set.
+0x36,CTAP2_ERR_PIN_REQUIRED,PIN is required for the selected operation.
+0x37,CTAP2_ERR_PIN_POLICY_VIOLATION,PIN policy violation. Currently only enforces minimum length.
+0x38,CTAP2_ERR_PIN_TOKEN_EXPIRED,pinToken expired on authenticator.
+0x39,CTAP2_ERR_REQUEST_TOO_LARGE,Authenticator cannot handle this request due to memory constraints.
+0x3A,CTAP2_ERR_ACTION_TIMEOUT,The current operation has timed out.
+0x3B,CTAP2_ERR_UP_REQUIRED,User presence is required for the requested operation.
+0x7F,CTAP1_ERR_OTHER,Other unspecified error.
+0xDF,CTAP2_ERR_SPEC_LAST,CTAP 2 spec last error.
+0xE0,CTAP2_ERR_EXTENSION_FIRST,Extension specific error.
+0xEF,CTAP2_ERR_EXTENSION_LAST,Extension specific error.
+0xF0,CTAP2_ERR_VENDOR_FIRST,Vendor specific error.
+0xFF,CTAP2_ERR_VENDOR_LAST,Vendor specific error.

examples/hmac.rs

@@ -0,0 +1,63 @@
+extern crate ctap_hmac as ctap;
+
+use crypto::digest::Digest;
+use crypto::sha2::Sha256;
+use ctap::extensions::hmac::HmacExtension;
+use ctap::{FidoAssertionRequestBuilder, FidoCredential, FidoCredentialRequestBuilder};
+use hex;
+use std::env::args;
+use std::io::prelude::*;
+use std::io::stdin;
+use std::io::stdout;
+
+const RP_ID: &str = "ctap_demo";
+
+fn main() -> ctap::FidoResult<()> {
+    let mut devices = ctap::get_devices()?;
+    let device_info = &mut devices.next().expect("No authenticator found");
+    let mut device = ctap::FidoDevice::new(device_info)?;
+
+    let credential = match args().skip(1).next().map(|h| FidoCredential {
+        id: hex::decode(&h).expect("Invalid credential"),
+        public_key: None,
+    }) {
+        Some(cred) => cred,
+        _ => {
+            let req = FidoCredentialRequestBuilder::default()
+                .rp_id(RP_ID)
+                .rp_name("ctap_hmac crate")
+                .user_name("example")
+                .uv(false)
+                .build()
+                .unwrap();
+
+            println!("Authorize using your device");
+            let cred = device
+                .make_hmac_credential(&req)
+                .expect("Failed to request credential");
+            println!("Credential: {}\nNote: You can pass this credential as first argument in order to reproduce results", hex::encode(&cred.id));
+            cred
+        }
+    };
+    print!("Type in your message: ");
+    stdout().flush().unwrap();
+    let mut message = String::new();
+    stdin()
+        .read_line(&mut message)
+        .expect("Couldn't get your message\nNote: this demo does not accept binary data");
+    println!("Authorize using your device");
+
+    let mut salt = [0u8; 32];
+    let mut digest = Sha256::new();
+    digest.input(&message.as_bytes());
+    digest.result(&mut salt);
+    let credential = &&credential;
+    let request = FidoAssertionRequestBuilder::default()
+        .rp_id(RP_ID)
+        .credential(credential)
+        .build()
+        .unwrap();
+    let (_cred, (hash1, _hash2)) = device.get_hmac_assertion(&request, &salt, None)?;
+    println!("Hash: {}", hex::encode(&hash1));
+    Ok(())
+}

examples/multiple.rs

@@ -0,0 +1,49 @@
+extern crate ctap_hmac as ctap;
+use ctap::{
+    FidoAssertionRequestBuilder, FidoCredential, FidoCredentialRequestBuilder, FidoDevice,
+    FidoResult,
+};
+
+use hex;
+use std::env::args;
+use std::time::Duration;
+
+const RP_ID: &str = "ctap_demo";
+
+fn main() -> ctap::FidoResult<()> {
+    let mut credentials = args()
+        .skip(1)
+        .map(|id| FidoCredential {
+            id: hex::decode(&id).expect("Invalid credential"),
+            public_key: None,
+        })
+        .collect::<Vec<_>>();
+    if credentials.len() == 0 {
+        credentials = ctap::get_devices()?
+            .map(|h| {
+                FidoDevice::new(&h).and_then(|mut dev| {
+                    FidoCredentialRequestBuilder::default()
+                        .rp_id(RP_ID)
+                        .user_name("test")
+                        .build()
+                        .unwrap()
+                        .make_credential(&mut dev)
+                })
+            })
+            .collect::<FidoResult<Vec<FidoCredential>>>()?;
+    }
+    let credentials = credentials.iter().collect::<Vec<_>>();
+    let req = FidoAssertionRequestBuilder::default()
+        .rp_id(RP_ID)
+        .credentials(&credentials[..])
+        .build()
+        .unwrap();
+    let mut devices = ctap::get_devices()?
+        .map(|handle| FidoDevice::new(&handle))
+        .collect::<FidoResult<Vec<_>>>()?;
+    // run with --features request_multiple
+    let (cred, _) =
+        ctap::get_assertion_devices(&req, devices.iter_mut(), Some(Duration::from_secs(10)))?;
+    println!("Success, got assertion for: {}", hex::encode(&cred.id));
+    Ok(())
+}

src/cbor.rs

@@ -4,11 +4,12 @@
 // 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 cbor_codec::value::Value;
+use cbor_codec::{Config, Decoder, Encoder, GenericDecoder, GenericEncoder};
+use cbor::skip::Skip;
 
-use byteorder::{WriteBytesExt, ReadBytesExt, BigEndian, ByteOrder};
+use byteorder::{BigEndian, ByteOrder, ReadBytesExt, WriteBytesExt};
 use failure::ResultExt;
 
 use std::collections::HashMap;
@@ -29,25 +30,23 @@ impl<'a> Request<'a> {
         match self {
             Request::MakeCredential(req) => req.encode(&mut encoder),
             Request::GetAssertion(req) => req.encode(&mut encoder),
-            Request::GetInfo => {
+            Request::GetInfo => encoder
-                encoder
+                .writer()
-                    .writer()
+                .write_u8(0x04)
-                    .write_u8(0x04)
+                .context(FidoErrorKind::CborEncode)
-                    .context(FidoErrorKind::CborEncode)
+                .map_err(From::from),
-                    .map_err(From::from)
-            }
             Request::ClientPin(req) => req.encode(&mut encoder),
         }
     }
 
-    pub fn decode<R: ReadBytesExt>(&self, reader: R) -> FidoResult<Response> {
+    pub fn decode<R: ReadBytesExt + Skip>(&self, reader: R) -> FidoResult<Response> {
         Ok(match self {
-            Request::MakeCredential(_) => Response::MakeCredential(
+            Request::MakeCredential(_) => {
-                MakeCredentialResponse::decode(reader)?,
+                Response::MakeCredential(MakeCredentialResponse::decode(reader)?)
-            ),
+            }
-            Request::GetAssertion(_) => Response::GetAssertion(
+            Request::GetAssertion(_) => {
-                GetAssertionResponse::decode(reader)?,
+                Response::GetAssertion(GetAssertionResponse::decode(reader)?)
-            ),
+            }
             Request::GetInfo => Response::GetInfo(GetInfoResponse::decode(reader)?),
             Request::ClientPin(_) => Response::ClientPin(ClientPinResponse::decode(reader)?),
         })
@@ -77,13 +76,18 @@ pub struct MakeCredentialRequest<'a> {
 
 impl<'a> MakeCredentialRequest<'a> {
     pub fn encode<W: WriteBytesExt>(&self, mut encoder: &mut Encoder<W>) -> FidoResult<()> {
-        encoder.writer().write_u8(0x01).context(
+        encoder
-            FidoErrorKind::CborEncode,
+            .writer()
-        )?; // authenticatorMakeCredential
+            .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
+            .options
+            .as_ref()
+            .map(|opt| opt.encoded())
+            .unwrap_or(false) as usize;
         length += self.pin_auth.is_some() as usize;
         length += self.pin_protocol.is_some() as usize;
         encoder.object(length)?;
@@ -146,7 +150,7 @@ 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))?
+            Err(FidoErrorKind::CborError(CborErrorCode::from(status)))?
         }
         let mut decoder = Decoder::new(Config::default(), reader);
         let mut response = MakeCredentialResponse::default();
@@ -176,13 +180,18 @@ pub struct GetAssertionRequest<'a> {
 
 impl<'a> GetAssertionRequest<'a> {
     pub fn encode<W: WriteBytesExt>(&self, mut encoder: &mut Encoder<W>) -> FidoResult<()> {
-        encoder.writer().write_u8(0x02).context(
+        encoder
-            FidoErrorKind::CborEncode,
+            .writer()
-        )?; // authenticatorGetAssertion
+            .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
+            .options
+            .as_ref()
+            .map(|opt| opt.encoded())
+            .unwrap_or(false) as usize;
         length += self.pin_auth.is_some() as usize;
         length += self.pin_protocol.is_some() as usize;
         encoder.object(length)?;
@@ -236,7 +245,7 @@ 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))?
+            Err(FidoErrorKind::CborError(CborErrorCode::from(status)))?
         }
         let mut decoder = Decoder::new(Config::default(), reader);
         let mut response = GetAssertionResponse::default();
@@ -269,10 +278,10 @@ pub struct GetInfoResponse {
 }
 
 impl GetInfoResponse {
-    pub fn decode<R: ReadBytesExt>(mut reader: R) -> FidoResult<Self> {
+    pub fn decode<R: ReadBytesExt + Skip>(mut reader: R) -> FidoResult<Self> {
         let status = reader.read_u8().context(FidoErrorKind::CborDecode)?;
         if status != 0 {
-            Err(FidoErrorKind::CborError(status))?
+            Err(FidoErrorKind::CborError(CborErrorCode::from(status)))?
         }
         let mut decoder = Decoder::new(Config::default(), reader);
         let mut response = GetInfoResponse::default();
@@ -296,7 +305,7 @@ impl GetInfoResponse {
                         response.pin_protocols.push(decoder.u8()?);
                     }
                 }
-                _ => continue,
+                _ => decoder.skip()?,
             }
         }
         Ok(response)
@@ -315,9 +324,10 @@ pub struct ClientPinRequest<'a> {
 
 impl<'a> ClientPinRequest<'a> {
     pub fn encode<W: WriteBytesExt>(&self, encoder: &mut Encoder<W>) -> FidoResult<()> {
-        encoder.writer().write_u8(0x06).context(
+        encoder
-            FidoErrorKind::CborEncode,
+            .writer()
-        )?; // authenticatorClientPIN
+            .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;
@@ -359,7 +369,7 @@ 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))?
+            Err(FidoErrorKind::CborError(CborErrorCode::from(status)))?
         }
         let mut decoder = Decoder::new(Config::default(), reader);
         let mut response = ClientPinResponse::default();
@@ -383,7 +393,6 @@ impl ClientPinResponse {
     }
 }
 
-
 #[derive(Debug)]
 pub struct OptionsInfo {
     pub plat: bool,
@@ -415,7 +424,9 @@ impl OptionsInfo {
                 "clientPin" => options.client_pin = Some(decoder.bool()?),
                 "up" => options.up = decoder.bool()?,
                 "uv" => options.uv = Some(decoder.bool()?),
-                _ => continue,
+                _ => {
+                    decoder.bool()?;
+                }
             }
         }
         Ok(options)
@@ -439,21 +450,28 @@ impl AuthenticatorData {
         let flags = bytes[32];
         data.up = (flags & 0x01) == 0x01;
         data.uv = (flags & 0x02) == 0x02;
+        let is_attested = (flags & 0x40) == 0x40;
+        let has_extension_data = (flags & 0x80) == 0x80;
         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)?;
+        if is_attested {
-        data.attested_credential_data = attested_credential_data;
+            let attested_credential_data = AttestedCredentialData::from_bytes(&mut cur)?;
-        if cur.position() >= (bytes.len() - 37) as u64 {
+            data.attested_credential_data = attested_credential_data;
-            return Ok(data);
+            if cur.position() >= (bytes.len() - 37) as u64 {
+                return Ok(data);
+            }
         }
-        let mut decoder = GenericDecoder::new(Config::default(), cur);
+        if has_extension_data {
-        for _ in 0..decoder.borrow_mut().object()? {
+            let mut decoder = GenericDecoder::new(Config::default(), cur);
-            let key = decoder.borrow_mut().text()?;
+            for _ in 0..decoder.borrow_mut().object()? {
-            let value = decoder.value()?;
+                let key = decoder.borrow_mut().text()?;
-            data.extensions.insert(key.to_string(), value);
+                let value = decoder.value()?;
+                data.extensions.insert(key.to_string(), value);
+            }
         }
         Ok(data)
     }
@@ -494,15 +512,15 @@ impl P256Key {
         if cose.key_type != 2 || cose.algorithm != -7 {
             Err(FidoErrorKind::KeyType)?
         }
-        if let (Some(Value::U8(curve)),
+        if let (
-                Some(Value::Bytes(value::Bytes::Bytes(x))),
+            Some(Value::U8(curve)),
-                Some(Value::Bytes(value::Bytes::Bytes(y)))) =
+            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(&-1),
-                cose.parameters.get(&-3),
+            cose.parameters.get(&-2),
-            )
+            cose.parameters.get(&-3),
-        {
+        ) {
             if *curve != 1 {
                 Err(FidoErrorKind::KeyType)?
             }
@@ -532,9 +550,10 @@ impl P256Key {
                 (-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()
+            .iter()
-                .collect(),
+            .cloned()
+            .collect(),
         }
     }
 
@@ -579,14 +598,45 @@ impl CoseKey {
         let mut cose_key = CoseKey::default();
         cose_key.algorithm = -7;
         for _ in 0..items {
-            match generic.borrow_mut().i16()? {
+            match generic.value()? {
-                0x01 => cose_key.key_type = generic.borrow_mut().u16()?,
+                Value::Text(value::Text::Text(text)) => match &text[..] {
-                0x02 => cose_key.algorithm = generic.borrow_mut().i32()?,
+                    "type" => {
-                key if key < 0 => {
+                        cose_key.key_type = match generic.value()? {
-                    cose_key.parameters.insert(key, generic.value()?);
+                            Value::Text(value::Text::Text(type_)) if &type_ == "public-key" => 0u16,
+                            Value::U16(i) => i,
+                            Value::U8(i) => i.into(),
+                            _ => {
+                                continue;
+                            }
+                        }
+                    }
+                    "alg" => cose_key.algorithm = generic.borrow_mut().i32()?,
+                    _ => continue,
+                },
+                val @ Value::I8(_)
+                | val @ Value::I16(_)
+                | val @ Value::U16(_)
+                | val @ Value::U8(_) => {
+                    let int_val = match val {
+                        Value::I8(i) => i as i32,
+                        Value::I16(i) => i as i32,
+                        Value::U8(i) => i as i32,
+                        Value::U16(i) => i as i32,
+                        _ => unreachable!(),
+                    };
+                    match int_val {
+                        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 as i16, generic.value()?);
+                        }
+                        unknown => {
+                            (unknown, generic.value()?); // skip unknown parameter
+                        }
+                    }
                 }
-                _ => {
+                unknown => {
-                    generic.value()?; // skip unknown parameter
+                    (unknown, generic.value()?); // skip unknown parameter
                 }
             }
         }
@@ -684,15 +734,16 @@ impl PublicKeyCredentialDescriptor {
 pub struct AuthenticatorOptions {
     pub rk: bool,
     pub uv: bool,
+    pub up: bool,
 }
 
 impl AuthenticatorOptions {
     pub fn encoded(&self) -> bool {
-        self.rk || self.uv
+        self.rk || self.uv || self.up
     }
 
     pub fn encode<W: WriteBytesExt>(&self, encoder: &mut Encoder<W>) -> FidoResult<()> {
-        let length = (self.rk as usize) + (self.uv as usize);
+        let length = (self.rk as usize) + (self.uv as usize) + (self.up as usize);
         encoder.object(length)?;
         if self.rk {
             encoder.text("rk")?;
@@ -702,6 +753,10 @@ impl AuthenticatorOptions {
             encoder.text("uv")?;
             encoder.bool(true)?;
         }
+        if self.up {
+            encoder.text("up")?;
+            encoder.bool(true)?;
+        }
         Ok(())
     }
 }

src/crypto.rs

@@ -4,15 +4,16 @@
 // 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::*;
+use failure::ResultExt;
+use ring::error::Unspecified;
+use ring::{agreement, digest, hmac, rand, signature};
+use rust_crypto::aes;
+use rust_crypto::blockmodes::NoPadding;
+use rust_crypto::buffer::{RefReadBuffer, RefWriteBuffer};
+use rust_crypto::symmetriccipher::{Decryptor, Encryptor};
+use untrusted::Input;
 
 #[derive(Debug)]
 pub struct SharedSecret {
@@ -26,9 +27,9 @@ impl SharedSecret {
         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(
+        private
-            FidoErrorKind::GenerateKey,
+            .compute_public_key(public)
-        )?;
+            .context(FidoErrorKind::GenerateKey)?;
         let peer = P256Key::from_cose(peer_key)
             .context(FidoErrorKind::ParsePublic)?
             .bytes();
@@ -39,7 +40,8 @@ impl SharedSecret {
             peer,
             Unspecified,
             |material| Ok(digest::digest(&digest::SHA256, material)),
-        ).context(FidoErrorKind::GenerateSecret)?;
+        )
+        .context(FidoErrorKind::GenerateSecret)?;
         let mut res = SharedSecret {
             public_key: P256Key::from_bytes(&public)
                 .context(FidoErrorKind::ParsePublic)?
@@ -50,42 +52,46 @@ impl SharedSecret {
         Ok(res)
     }
 
-    pub fn encrypt_pin(&self, pin: &str) -> FidoResult<[u8; 16]> {
+    pub fn encryptor(&self) -> Box<dyn Encryptor + 'static> {
-        let mut encryptor = aes::cbc_encryptor(
+        aes::cbc_encryptor(
             aes::KeySize::KeySize256,
             &self.shared_secret,
             &[0u8; 16],
             NoPadding,
-        );
+        )
+    }
+
+    pub fn encrypt_pin(&self, pin: &str) -> FidoResult<[u8; 16]> {
+        let mut encryptor = self.encryptor();
         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(
+        encryptor
-            |_| {
+            .encrypt(&mut input, &mut output, true)
-                FidoErrorKind::EncryptPin
+            .map_err(|_| FidoErrorKind::EncryptPin)?;
-            },
-        )?;
         Ok(out_bytes)
     }
 
-    pub fn decrypt_token(&self, data: &mut [u8]) -> FidoResult<PinToken> {
+    pub fn decryptor(&self) -> Box<dyn Decryptor + 'static> {
-        let mut decryptor = aes::cbc_decryptor(
+        aes::cbc_decryptor(
             aes::KeySize::KeySize256,
             &self.shared_secret,
             &[0u8; 16],
             NoPadding,
-        );
+        )
+    }
+
+    pub fn decrypt_token(&self, data: &mut [u8]) -> FidoResult<PinToken> {
+        let mut decryptor = self.decryptor();
         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(
+        decryptor
-            |_| {
+            .decrypt(&mut input, &mut output, true)
-                FidoErrorKind::DecryptPin
+            .map_err(|_| FidoErrorKind::DecryptPin)?;
-            },
-        )?;
         Ok(PinToken(hmac::SigningKey::new(&digest::SHA256, &out_bytes)))
     }
 }
@@ -119,5 +125,6 @@ pub fn verify_signature(
         public_key,
         msg,
         signature,
-    ).is_ok()
+    )
+    .is_ok()
 }

src/error.rs

@@ -4,21 +4,53 @@
 // 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 cbor_codec::{DecodeError, EncodeError};
-
+use failure::_core::fmt::{Error, Formatter};
+use failure::_core::option::Option;
+use failure::{Backtrace, Context, Fail};
 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(Debug, Copy, Clone, Fail, Eq, PartialEq)]
+pub struct CborErrorCode(u8);
+
+// generated using build.rs
+include!(concat!(env!("OUT_DIR"), "/ctap_error_codes.rs"));
+
+impl CborErrorCode {
+    fn detail(&self) -> Option<(u8, &'static str, &'static str)> {
+        for (code, name, desc) in CTAP_ERROR_CODES {
+            if *code == self.0 as usize {
+                return Some((self.0, name, desc));
+            }
+        }
+        None
+    }
+
+    pub fn name(&self) -> Option<&'static str> {
+        self.detail().map(|(_, name, _)| name)
+    }
+
+    pub fn description(&self) -> Option<&'static str> {
+        self.detail().map(|(_, _, desc)| desc)
+    }
+
+    pub fn code(&self) -> u8 {
+        self.0
+    }
+}
+
 #[derive(Copy, Clone, Eq, PartialEq, Debug, Fail)]
 pub enum FidoErrorKind {
     #[fail(display = "Read/write error with device.")]
     Io,
+    #[fail(display = "Operation timed out")]
+    Timeout,
     #[fail(display = "Error while reading packet from device.")]
     ReadPacket,
     #[fail(display = "Error while writing packet to device.")]
@@ -41,10 +73,12 @@ pub enum FidoErrorKind {
     EncryptPin,
     #[fail(display = "Failed to decrypt PIN.")]
     DecryptPin,
-    #[fail(display = "Supplied key has incorrect type.")]
+    #[fail(display = "Failed to verify response signature.")]
+    VerifySignature,
+    #[fail(display = "Failed to verify response signature.")]
     KeyType,
-    #[fail(display = "Device returned error: 0x{:x}", _0)]
+    #[fail(display = "Device returned error: {}", _0)]
-    CborError(u8),
+    CborError(CborErrorCode),
     #[fail(display = "Device does not support FIDO2")]
     DeviceUnsupported,
     #[fail(display = "This operating requires a PIN but none was provided.")]
@@ -52,7 +86,7 @@ pub enum FidoErrorKind {
 }
 
 impl Fail for FidoError {
-    fn cause(&self) -> Option<&Fail> {
+    fn cause(&self) -> Option<&dyn Fail> {
         self.0.cause()
     }
 
@@ -99,3 +133,33 @@ impl From<DecodeError> for FidoError {
         FidoError(err.context(FidoErrorKind::CborDecode))
     }
 }
+
+impl From<u8> for CborErrorCode {
+    fn from(code: u8) -> Self {
+        Self(code)
+    }
+}
+
+impl Display for CborErrorCode {
+    fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
+        if let Some((code, _name, desc)) = self.detail() {
+            write!(f, "CborError: 0x{:x?}: {}", code, desc)?;
+        } else {
+            write!(f, "CborError: 0x{:x?}: unknown", self.code())?;
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn cbor_error_code() {
+        assert_eq!(
+            CborErrorCode(0x33).to_string(),
+            "CborError: 0x33: PIN authentication, pinAuth, verification failed."
+        )
+    }
+}

src/extensions/hmac.rs

@@ -0,0 +1,206 @@
+use crate::{FidoAssertionRequest, FidoAssertionRequestBuilder, FidoCredentialRequest};
+use crate::{FidoCredential, FidoDevice, FidoErrorKind, FidoResult};
+use cbor_codec::value::{Bytes, Int, Key, Text, Value};
+use cbor_codec::Encoder;
+use cbor_codec::{Config, GenericDecoder};
+use rust_crypto::buffer::{RefReadBuffer, RefWriteBuffer};
+use rust_crypto::digest::Digest;
+use rust_crypto::hmac::Hmac;
+use rust_crypto::mac::Mac;
+use rust_crypto::sha2::Sha256;
+use std::collections::BTreeMap;
+use std::io::Cursor;
+
+pub trait HmacExtension {
+    fn extension_name() -> &'static str {
+        "hmac-secret"
+    }
+
+    fn extension_input() -> &'static Value {
+        &Value::Bool(true)
+    }
+
+    /// Generates data for the extension field as part of the assertion request
+    fn get_dict(&mut self, salt: &[u8; 32], salt2: Option<&[u8; 32]>) -> FidoResult<Value> {
+        let mut map = BTreeMap::new();
+        map.insert(
+            Key::Text(Text::Text(
+                <Self as HmacExtension>::extension_name().to_owned(),
+            )),
+            self.get_data(salt, salt2)?,
+        );
+        Ok(Value::Map(map))
+    }
+
+    fn get_data(&mut self, salt: &[u8; 32], salt2: Option<&[u8; 32]>) -> FidoResult<Value>;
+
+    /// Convenience function to create an credential which includes extension specific data
+    /// Use `FidoDevice::make_credential` if you need more control
+    fn make_hmac_credential(
+        &mut self,
+        request: &FidoCredentialRequest,
+    ) -> FidoResult<FidoCredential>;
+
+    /// Request an assertion from the authenticator for a given credential and salt(s).
+    /// at least one `salt` must be provided, consider using a hashing function like SHA256
+    /// to ensure that your salt will fit 32 bytes.
+    /// Salt(s), credential and the authenticator internal secret will then be used to
+    /// generate a secret.
+    ///
+    /// This method will return the secret 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.
+    ///
+    fn get_hmac_assertion<'a: 'b, 'b>(
+        &mut self,
+        assertion: &FidoAssertionRequest<'a, 'b>,
+        salt: &[u8; 32],
+        salt2: Option<&[u8; 32]>,
+    ) -> FidoResult<(&'a FidoCredential, ([u8; 32], Option<[u8; 32]>))>;
+
+    /// Convenience function for `get_hmac_assertion` that will accept arbitrary
+    /// lenght input which will then be hashed and passed on
+    fn hmac_challange(
+        &mut self,
+        rp_id: &str,
+        credential: &FidoCredential,
+        input: &[u8],
+    ) -> FidoResult<[u8; 32]> {
+        let mut salt = [0u8; 32];
+        let mut digest = Sha256::new();
+        digest.input(input);
+        digest.result(&mut salt);
+        self.get_hmac_assertion(
+            &FidoAssertionRequestBuilder::default()
+                .rp_id(rp_id)
+                .credential(&credential)
+                .build()
+                .unwrap(),
+            &salt,
+            None,
+        )
+        .map(|(_cred, secret)| secret.0)
+    }
+}
+
+impl HmacExtension for FidoDevice {
+    fn get_data(&mut self, salt: &[u8; 32], salt2: Option<&[u8; 32]>) -> FidoResult<Value> {
+        let shared_secret = self.shared_secret.as_ref().unwrap();
+        let mut encryptor = shared_secret.encryptor();
+        let mut salt_enc = [0u8; 64];
+        let mut output = RefWriteBuffer::new(&mut salt_enc);
+        let mut encrypt = || {
+            encryptor.encrypt(&mut RefReadBuffer::new(salt), &mut output, salt2.is_none())?;
+            if let Some(salt2) = salt2 {
+                encryptor
+                    .encrypt(&mut RefReadBuffer::new(salt2), &mut output, true)
+                    .map(|_| ())
+            } else {
+                Ok(())
+            }
+        };
+        encrypt().map_err(|_| FidoErrorKind::Io)?;
+
+        let key_agreement = || {
+            let mut cur = Cursor::new(Vec::new());
+            let mut encoder = Encoder::new(&mut cur);
+            shared_secret.public_key.encode(&mut encoder).unwrap();
+            cur.set_position(0);
+            let mut dec = GenericDecoder::new(Config::default(), cur);
+            dec.value()
+        };
+
+        let mut map = BTreeMap::new();
+        map.insert(
+            Key::Int(Int::from_i64(0x01)),
+            key_agreement().map_err(|_| FidoErrorKind::Io)?,
+        );
+        map.insert(
+            Key::Int(Int::from_i64(0x02)),
+            Value::Bytes(Bytes::Bytes(
+                salt_enc[0..((salt2.is_some() as usize + 1) * 32)].to_vec(),
+            )),
+        );
+
+        let mut salt_hmac = Hmac::new(Sha256::new(), &shared_secret.shared_secret);
+        salt_hmac.input(&salt_enc[0..((salt2.is_some() as usize + 1) * 32)]);
+
+        let mut authed_salt_enc = [0u8; 32];
+        authed_salt_enc.copy_from_slice(salt_hmac.result().code());
+
+        map.insert(
+            Key::Int(Int::from_i64(0x03)),
+            Value::Bytes(Bytes::Bytes(authed_salt_enc[0..16].to_vec())),
+        );
+
+        Ok(Value::Map(map))
+    }
+
+    fn make_hmac_credential(
+        &mut self,
+        request: &FidoCredentialRequest,
+    ) -> FidoResult<FidoCredential> {
+        let mut request = request.clone();
+        request.rk = true;
+        request.extension_data.insert(
+            <Self as HmacExtension>::extension_name(),
+            <Self as HmacExtension>::extension_input(),
+        );
+        self.make_credential(&request)
+    }
+
+    fn get_hmac_assertion<'a: 'b, 'b>(
+        &mut self,
+        request: &FidoAssertionRequest<'a, 'b>,
+        salt: &[u8; 32],
+        salt2: Option<&[u8; 32]>,
+    ) -> FidoResult<(&'a FidoCredential, ([u8; 32], Option<[u8; 32]>))> {
+        while self.shared_secret.is_none() {
+            self.init_shared_secret()?;
+        }
+        let ext_data: Value = self.get_data(salt, salt2)?;
+        let mut request = request.clone();
+        request
+            .extension_data
+            .insert(<Self as HmacExtension>::extension_name(), &ext_data);
+
+        let (cred, auth_data) = self.get_assertion(&request)?;
+        let shared_secret = self.shared_secret.as_ref().unwrap();
+        let mut decryptor = shared_secret.decryptor();
+        let mut hmac_secret_combined = [0u8; 64];
+        let _output = RefWriteBuffer::new(&mut hmac_secret_combined);
+        let hmac_secret_enc = match auth_data
+            .extensions
+            .get(<Self as HmacExtension>::extension_name())
+            .ok_or(FidoErrorKind::CborDecode)?
+        {
+            Value::Bytes(hmac_ciphered) => Ok(match hmac_ciphered {
+                Bytes::Bytes(hmac_ciphered) => hmac_ciphered.to_vec(),
+                Bytes::Chunks(hmac_ciphered) => hmac_ciphered.iter().fold(Vec::new(), |s, i| {
+                    let mut s = s;
+                    s.extend_from_slice(&i);
+                    s
+                }),
+            }),
+            _ => Err(FidoErrorKind::CborDecode),
+        }?;
+        let mut hmac_secret = [0u8; 64];
+        decryptor
+            .decrypt(
+                &mut RefReadBuffer::new(&hmac_secret_enc),
+                &mut RefWriteBuffer::new(&mut hmac_secret),
+                true,
+            )
+            .map_err(|_| FidoErrorKind::ReadPacket)?;
+        let mut hmac_secret_0 = [0u8; 32];
+        let mut hmac_secret_1 = [0u8; 32];
+        hmac_secret_0.copy_from_slice(&hmac_secret[0..32]);
+        hmac_secret_1.copy_from_slice(&hmac_secret[32..]);
+        let cred = request
+            .credentials
+            .into_iter()
+            .find(|c| c.id == cred.id)
+            .unwrap();
+        Ok((cred, (hmac_secret_0, salt2.and(Some(hmac_secret_1)))))
+    }
+}

src/extensions/mod.rs

@@ -0,0 +1,2 @@
+pub mod hmac;
+pub use hmac::*;

src/hid_linux.rs

@@ -4,11 +4,11 @@
 // 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::*;
+use byteorder::{ByteOrder, LittleEndian};
+use std::fs;
+use std::io;
+use std::path::PathBuf;
 
 static REPORT_DESCRIPTOR_KEY_MASK: u8 = 0xfc;
 static LONG_ITEM_ENCODING: u8 = 0xfe;
@@ -18,9 +18,9 @@ static REPORT_SIZE: u8 = 0x74;
 
 pub fn enumerate() -> io::Result<impl Iterator<Item = DeviceInfo>> {
     fs::read_dir("/sys/class/hidraw").map(|entries| {
-        entries.filter_map(|entry| entry.ok()).filter_map(|entry| {
+        entries
-            path_to_device(&entry.path()).ok()
+            .filter_map(|entry| entry.ok())
-        })
+            .filter_map(|entry| path_to_device(&entry.path()).ok())
     })
 }
 

src/lib.rs

@@ -9,66 +9,76 @@
 //! # Example
 //!
 //! ```
-//! # fn do_fido() -> ctap::FidoResult<()> {
+//! # use ctap_hmac::*;
-//! let mut devices = ctap::get_devices()?;
+//! # fn do_fido() -> FidoResult<()> {
-//! let device_info = &devices.next().unwrap();
-//! let mut device = ctap::FidoDevice::new(device_info)?;
 //!
-//! // This can be omitted if the FIDO device is not configured with a PIN.
+//!use ctap_hmac::*;
-//! let pin = "test";
+//!let device_info = get_devices()?.next().expect("no device connected");
-//! device.unlock(pin)?;
+//!let mut device = FidoDevice::new(&device_info)?;
 //!
-//! // In a real application these values would come from the requesting app.
+//!// This can be omitted if the FIDO device is not configured with a PIN.
-//! let rp_id = "rp_id";
+//!let pin = "test";
-//! let user_id = [0];
+//!device.unlock(pin)?;
-//! let user_name = "user_name";
+//!
-//! let client_data_hash = [0; 32];
+//!// In a real application these values would come from the requesting app.
-//! let cred = device.make_credential(
+//!let cred_request = FidoCredentialRequestBuilder::default()
-//!     rp_id,
+//!     .rp_id("rp_id")
-//!     &user_id,
+//!     .user_name("user_name")
-//!     user_name,
+//!     .build().unwrap();
-//!     &client_data_hash
+//!let cred = device.make_credential(&cred_request)?;
-//! )?;
+//!let cred = &&cred;
+//!let assertion_request = FidoAssertionRequestBuilder::default()
+//!     .rp_id("rp_id")
+//!     .credential(cred)
+//!     .build().unwrap();
+//!// In a real application the credential would be stored and used later.
+//!let result = device.get_assertion(&assertion_request);
 //!
-//! // 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;
+extern crate rand;
 #[macro_use]
 extern crate failure_derive;
 #[macro_use]
 extern crate num_derive;
-extern crate num_traits;
+#[macro_use]
+extern crate derive_builder;
 extern crate byteorder;
 extern crate cbor as cbor_codec;
+extern crate crypto as rust_crypto;
+extern crate num_traits;
 extern crate ring;
 extern crate untrusted;
-extern crate crypto as rust_crypto;
 
-mod packet;
+mod cbor;
+mod crypto;
+mod error;
+pub mod extensions;
 mod hid_common;
 mod hid_linux;
-mod error;
+mod packet;
-mod crypto;
+mod util;
-mod cbor;
 
 use std::cmp;
-use std::u8;
-use std::u16;
 use std::fs;
-use std::io::{Write, Cursor};
+use std::io::{Cursor, Write};
+use std::u16;
+use std::u8;
 
-use failure::{Fail, ResultExt};
+use self::cbor::{AuthenticatorOptions, PublicKeyCredentialDescriptor};
-use rand::prelude::*;
+pub use self::error::*;
-use num_traits::FromPrimitive;
 use self::hid_linux as hid;
 use self::packet::CtapCommand;
-pub use self::error::*;
+pub use self::util::*;
+use crate::cbor::{AuthenticatorData, GetAssertionRequest};
+use failure::{Fail, ResultExt};
+use num_traits::FromPrimitive;
+use rand::prelude::*;
+use std::collections::BTreeMap;
 
 static BROADCAST_CID: [u8; 4] = [0xff, 0xff, 0xff, 0xff];
 
@@ -76,23 +86,18 @@ static BROADCAST_CID: [u8; 4] = [0xff, 0xff, 0xff, 0xff];
 pub fn get_devices() -> FidoResult<impl Iterator<Item = hid::DeviceInfo>> {
     hid::enumerate()
         .context(FidoErrorKind::Io)
-        .map(|devices| {
+        .map(|devices| devices.filter(|dev| dev.usage_page == 0xf1d0 && dev.usage == 0x21))
-            devices.filter(|dev| dev.usage_page == 0xf1d0 && dev.usage == 0x21)
-        })
         .map_err(From::from)
 }
 
 /// A credential created by a FIDO2 authenticator.
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 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>,
+    pub public_key: Option<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,
@@ -104,6 +109,145 @@ pub struct FidoDevice {
     aaguid: [u8; 16],
 }
 
+pub struct FidoCancelHandle {
+    device: fs::File,
+    packet_size: u16,
+    channel_id: [u8; 4],
+}
+
+impl FidoCancelHandle {
+    pub fn cancel(&mut self) -> FidoResult<()> {
+        let payload = &[1u8];
+        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));
+        packet::write_init_packet(
+            &mut self.device,
+            64,
+            &self.channel_id,
+            &CtapCommand::Cancel,
+            to_send,
+            frame,
+        )?;
+        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)) {
+            packet::write_cont_packet(&mut self.device, 64, &self.channel_id, seq, frame)?;
+        }
+        self.device.flush().context(FidoErrorKind::WritePacket)?;
+        Ok(())
+    }
+
+    pub fn cancel_after<T>(&mut self, body: impl Fn(()) -> T) -> FidoResult<T> {
+        let res = body(());
+        match self.cancel() {
+            Ok(_) => Ok(res),
+            Err(e) => Err(e),
+        }
+    }
+}
+
+/// 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.
+#[derive(Clone, Debug, Builder)]
+#[builder(setter(into))]
+#[builder(pattern = "owned")]
+pub struct FidoCredentialRequest<'a> {
+    /// create resident key
+    #[builder(default)]
+    rk: bool,
+    /// user verification
+    #[builder(default)]
+    uv: bool,
+    /// relying party id
+    rp_id: &'a str,
+    /// relying party id
+    #[builder(default)]
+    rp_name: Option<&'a str>,
+    /// relying party icon url
+    #[builder(default)]
+    rp_icon_url: Option<&'a str>,
+    /// user id
+    #[builder(default = "&[0u8]")]
+    user_id: &'a [u8],
+    /// user name
+    #[builder(default)]
+    user_name: Option<&'a str>,
+    /// user icon url
+    #[builder(default)]
+    user_icon_url: Option<&'a str>,
+    /// user display name
+    #[builder(default)]
+    user_display_name: Option<&'a str>,
+    #[builder(default = "&[]")]
+    exclude_list: &'a [&'a FidoCredential],
+    #[builder(default = "&[0u8; 32]")]
+    client_data_hash: &'a [u8],
+    #[builder(default)]
+    extension_data: BTreeMap<&'a str, &'a cbor_codec::value::Value>,
+}
+
+impl<'a> FidoCredentialRequest<'a> {
+    pub fn make_credential(&self, device: &mut FidoDevice) -> FidoResult<FidoCredential> {
+        device.make_credential(&self)
+    }
+}
+
+/// 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.
+#[derive(Clone, Debug, Builder)]
+#[builder(setter(into))]
+#[builder(pattern = "owned")]
+pub struct FidoAssertionRequest<'a, 'b> {
+    #[builder(default)]
+    up: bool,
+    #[builder(default)]
+    rk: bool,
+    #[builder(default)]
+    uv: bool,
+    /// The Relying Party ID provided by the platform when this key was generated.
+    rp_id: &'a str,
+    credentials: &'a [&'a FidoCredential],
+    #[builder(default = "&[]")]
+    exclude_list: &'a [&'a FidoCredential],
+    #[builder(default = "&[0u8; 32]")]
+    client_data_hash: &'a [u8],
+    #[builder(default)]
+    extension_data: BTreeMap<&'b str, &'b cbor_codec::value::Value>,
+}
+
+impl<'a, 'b> FidoAssertionRequest<'a, 'b> {
+    pub fn get_assertion(&self, device: &mut FidoDevice) -> FidoResult<&'a FidoCredential> {
+        device.get_assertion(self).map(|res| res.0)
+    }
+}
+
+impl<'a, 'b> FidoAssertionRequestBuilder<'a, 'b> {
+    pub fn credential(mut self, credential: &'a &'a FidoCredential) -> Self {
+        self.credentials = Some(std::slice::from_ref(credential));
+        self
+    }
+}
+
 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
@@ -143,10 +287,15 @@ impl FidoDevice {
             cbor::Response::GetInfo(resp) => resp,
             _ => Err(FidoErrorKind::CborDecode)?,
         };
-        if !response.versions.iter().any(|ver| ver == "FIDO_2_0") {
+        if !response.versions.iter().any(|ver| ["FIDO_2_0", "FIDO_2_1_PRE"].contains(&ver.as_str())) {
             Err(FidoErrorKind::DeviceUnsupported)?
         }
-        if !response.pin_protocols.iter().any(|ver| *ver == 1) {
+        // Require pin protocol version 1, only if pin-protocol is supported at all
+        if !response
+            .pin_protocols
+            .iter()
+            .any(|ver| *ver == 1) && response.pin_protocols.len() > 0
+        {
             Err(FidoErrorKind::DeviceUnsupported)?
         }
         self.needs_pin = response.options.client_pin == Some(true);
@@ -176,6 +325,11 @@ impl FidoDevice {
         }
     }
 
+    /// True if this authenticator requires a PIN
+    pub fn needs_pin(&self) -> bool {
+        self.needs_pin
+    }
+
     /// 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
@@ -208,6 +362,93 @@ impl FidoDevice {
         }
     }
 
+    pub fn cancel_handle(&mut self) -> FidoResult<FidoCancelHandle> {
+        Ok(self
+            .device
+            .try_clone()
+            .map(|device| FidoCancelHandle {
+                device,
+                packet_size: self.packet_size,
+                channel_id: self.channel_id,
+            })
+            .context(FidoErrorKind::Io)?)
+    }
+
+    pub fn make_credential(
+        &mut self,
+        request: &FidoCredentialRequest<'_>,
+    ) -> FidoResult<FidoCredential> {
+        let rp = cbor::PublicKeyCredentialRpEntity {
+            id: request.rp_id,
+            name: request.rp_name,
+            icon: request.rp_icon_url,
+        };
+        let user = cbor::PublicKeyCredentialUserEntity {
+            id: request.user_id,
+            name: request.user_name.unwrap_or(""),
+            icon: request.user_icon_url,
+            display_name: request.user_display_name,
+        };
+
+        let options = Some(AuthenticatorOptions {
+            up: false,
+            uv: request.uv,
+            rk: request.rk,
+        });
+        if self.needs_pin && self.pin_token.is_none() {
+            Err(FidoErrorKind::PinRequired)?
+        }
+        if request.client_data_hash.len() != 32 {
+            Err(FidoErrorKind::CborEncode)?
+        }
+        while self.shared_secret.is_none() {
+            self.init_shared_secret()?;
+        }
+        let pub_key_cred_params = [("public-key", -7)];
+        let pin_auth = self
+            .pin_token
+            .as_ref()
+            .map(|token| token.auth(&request.client_data_hash));
+        let request = cbor::MakeCredentialRequest {
+            client_data_hash: request.client_data_hash,
+            rp,
+            user,
+            pub_key_cred_params: &pub_key_cred_params,
+            exclude_list: &request
+                .exclude_list
+                .iter()
+                .map(|cred| PublicKeyCredentialDescriptor {
+                    cred_type: "public-key".into(),
+                    id: cred.id.clone(),
+                })
+                .collect::<Vec<_>>()[..],
+            extensions: &request
+                .extension_data
+                .iter()
+                .map(|(name, data)| (*name, *data))
+                .collect::<Vec<_>>()[..],
+            options,
+            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,
+            public_key: Some(Vec::from(&public_key[..])),
+        })
+    }
+
     /// 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.
@@ -221,121 +462,92 @@ impl FidoDevice {
     ///
     /// 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(
+    pub fn get_assertion<'a, 'b>(
         &mut self,
-        rp_id: &str,
+        assertion: &FidoAssertionRequest<'a, 'b>,
-        user_id: &[u8],
+    ) -> FidoResult<(&'a FidoCredential, AuthenticatorData)> {
-        user_name: &str,
+        while self.shared_secret.is_none() {
-        client_data_hash: &[u8],
+            self.init_shared_secret()?;
-    ) -> FidoResult<FidoCredential> {
+        }
         if self.needs_pin && self.pin_token.is_none() {
             Err(FidoErrorKind::PinRequired)?
         }
-        if client_data_hash.len() != 32 {
+        if assertion.client_data_hash.len() != 32 {
             Err(FidoErrorKind::CborEncode)?
         }
-        let pin_auth = self.pin_token.as_ref().map(
+        let pin_auth = self
-            |token| token.auth(&client_data_hash),
+            .pin_token
-        );
+            .as_ref()
-        let rp = cbor::PublicKeyCredentialRpEntity {
+            .map(|token| token.auth(&assertion.client_data_hash));
-            id: rp_id,
+        let request = GetAssertionRequest {
-            name: None,
+            rp_id: assertion.rp_id,
-            icon: None,
+            client_data_hash: assertion.client_data_hash,
-        };
+            allow_list: &assertion
-        let user = cbor::PublicKeyCredentialUserEntity {
+                .credentials
-            id: user_id,
+                .iter()
-            name: user_name,
+                .map(|cred| PublicKeyCredentialDescriptor {
-            icon: None,
+                    cred_type: "public-key".into(),
-            display_name: None,
+                    id: cred.id.clone(),
-        };
+                })
-        let pub_key_cred_params = [("public-key", -7)];
+                .collect::<Vec<_>>()[..],
-        let request = cbor::MakeCredentialRequest {
+            extensions: &assertion
-            client_data_hash,
+                .extension_data
-            rp,
+                .iter()
-            user,
+                .map(|(name, data)| (*name, *data))
-            pub_key_cred_params: &pub_key_cred_params,
+                .collect::<Vec<_>>()[..],
-            exclude_list: Default::default(),
+            options: Some(AuthenticatorOptions {
-            extensions: Default::default(),
+                rk: assertion.rk,
-            options: Some(cbor::AuthenticatorOptions {
+                uv: assertion.uv,
-                rk: false,
+                up: assertion.up,
-                uv: true,
             }),
-            pin_auth,
+            pin_auth: 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(
+        let credential = assertion
-            &credential.public_key,
+            .credentials
-            &client_data_hash,
+            .iter()
-            &response.auth_data_bytes,
+            .flat_map(|cred| {
-            &response.signature,
+                response
-        ))
+                    .credential
+                    .as_ref()
+                    .filter(|rcred| rcred.id == cred.id)
+                    .map(|_| *cred)
+            })
+            .next();
+
+        credential
+            .and_then(|cred| {
+                if cred
+                    .public_key
+                    .as_ref()
+                    .map(|public_key| {
+                        crypto::verify_signature(
+                            &public_key,
+                            &assertion.client_data_hash,
+                            &response.auth_data_bytes,
+                            &response.signature,
+                        )
+                    })
+                    .unwrap_or(true)
+                {
+                    Some(cred)
+                } else {
+                    None
+                }
+            })
+            .ok_or(FidoError::from(FidoErrorKind::VerifySignature))
+            .map(|cred| (cred, response.auth_data))
     }
 
     fn cbor(&mut self, request: cbor::Request) -> FidoResult<cbor::Response> {
         let mut buf = Cursor::new(Vec::new());
-        request.encode(&mut buf).context(FidoErrorKind::CborEncode)?;
+        request
+            .encode(&mut buf)
+            .context(FidoErrorKind::CborEncode)?;
         let response = self.exchange(CtapCommand::Cbor, &buf.into_inner())?;
         request
             .decode(Cursor::new(response))
@@ -372,11 +584,9 @@ impl FidoDevice {
         while first_packet.is_none() {
             let packet = packet::InitPacket::from_reader(&mut self.device, 64)?;
             if packet.cmd == CtapCommand::Error {
-                Err(
+                Err(packet::CtapError::from_u8(packet.payload[0])
-                    packet::CtapError::from_u8(packet.payload[0])
+                    .unwrap_or(packet::CtapError::Other)
-                        .unwrap_or(packet::CtapError::Other)
+                    .context(FidoErrorKind::ParseCtap))?
-                        .context(FidoErrorKind::ParseCtap),
-                )?
             }
             if packet.cid == self.channel_id && &packet.cmd == cmd {
                 first_packet = Some(packet);

src/packet.rs

@@ -4,9 +4,9 @@
 // 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};
-use failure::ResultExt;
 use super::error::*;
+use failure::ResultExt;
+use num_traits::{FromPrimitive, ToPrimitive};
 
 use std::io::{Read, Write};
 
@@ -81,9 +81,9 @@ pub fn write_init_packet<W: Write>(
         Err(FidoErrorKind::WritePacket)?
     }
     packet.resize(report_size + 1, 0);
-    writer.write_all(&packet).context(
+    writer
-        FidoErrorKind::WritePacket,
+        .write_all(&packet)
-    )?;
+        .context(FidoErrorKind::WritePacket)?;
     Ok(())
 }
 
@@ -98,9 +98,9 @@ impl InitPacket {
     pub fn from_reader<R: Read>(mut reader: R, report_size: usize) -> FidoResult<InitPacket> {
         let mut buf = Vec::with_capacity(report_size);
         buf.resize(report_size, 0);
-        reader.read_exact(&mut buf[0..report_size]).context(
+        reader
-            FidoErrorKind::ReadPacket,
+            .read_exact(&mut buf[0..report_size])
-        )?;
+            .context(FidoErrorKind::ReadPacket)?;
         let mut cid = [0; 4];
         cid.copy_from_slice(&buf[0..4]);
         let cmd = match CtapCommand::from_u8(buf[4] ^ FRAME_INIT) {
@@ -142,9 +142,9 @@ pub fn write_cont_packet<W: Write>(
         Err(FidoErrorKind::WritePacket)?
     }
     packet.resize(report_size + 1, 0);
-    writer.write_all(&packet).context(
+    writer
-        FidoErrorKind::WritePacket,
+        .write_all(&packet)
-    )?;
+        .context(FidoErrorKind::WritePacket)?;
     Ok(())
 }
 
@@ -162,9 +162,9 @@ impl ContPacket {
     ) -> FidoResult<ContPacket> {
         let mut buf = Vec::with_capacity(report_size);
         buf.resize(report_size, 0);
-        reader.read_exact(&mut buf[0..report_size]).context(
+        reader
-            FidoErrorKind::ReadPacket,
+            .read_exact(&mut buf[0..report_size])
-        )?;
+            .context(FidoErrorKind::ReadPacket)?;
         let mut cid = [0; 4];
         cid.copy_from_slice(&buf[0..4]);
         let seq = buf[4];

src/util.rs

@@ -0,0 +1,88 @@
+#[cfg(feature = "request_multiple")]
+use crate::{
+    cbor::AuthenticatorData, FidoAssertionRequest, FidoCredential, FidoCredentialRequest,
+    FidoDevice, FidoErrorKind, FidoResult,
+};
+#[cfg(feature = "request_multiple")]
+use crossbeam::thread;
+#[cfg(feature = "request_multiple")]
+use std::sync::mpsc::channel;
+#[cfg(feature = "request_multiple")]
+use std::time::Duration;
+#[cfg(feature = "request_multiple")]
+pub fn request_multiple_devices<
+    'a,
+    T: Send + 'a,
+    F: Fn(&mut FidoDevice) -> FidoResult<T> + 'a + Sync,
+>(
+    devices: impl Iterator<Item = (&'a mut FidoDevice, &'a F)>,
+    timeout: Option<Duration>,
+) -> FidoResult<T> {
+    thread::scope(|scope| -> FidoResult<T> {
+        let (tx, rx) = channel();
+        let handles = devices
+            .map(|(device, fn_)| {
+                let cancel = device.cancel_handle()?;
+                let tx = tx.clone();
+                let thread_handle = scope.spawn(move |_| tx.send(fn_(device)));
+                Ok((cancel, thread_handle))
+            })
+            .collect::<FidoResult<Vec<_>>>()?;
+        let mut err = None;
+        let mut slept = Duration::from_millis(0);
+        let interval = Duration::from_millis(10);
+        let mut received = 0usize;
+        let res = loop {
+            match timeout {
+                Some(t) if t < slept => {
+                    break if let Some(cause) = err {
+                        cause
+                    } else {
+                        Err(FidoErrorKind::Timeout.into())
+                    };
+                }
+                _ => (),
+            }
+            if timeout.map(|t| t < slept).unwrap_or(true) {}
+            if let Ok(msg) = rx.recv_timeout(interval) {
+                received += 1;
+                match msg {
+                    e @ Err(_) if received == handles.len() => break e,
+                    e @ Err(_) => err = Some(e),
+                    res @ Ok(_) => break res,
+                }
+            } else {
+                slept += interval;
+            }
+        };
+        for (mut cancel, join) in handles {
+            // Canceling out of courtesy don't care if it fails
+            let _ = cancel.cancel();
+            let _ = join.join();
+        }
+        res
+    })
+    .unwrap()
+}
+
+/// Will send the `assertion_request` to all supplied `devices` and return either the first successful assertion or the last error
+#[cfg(feature = "request_multiple")]
+pub fn get_assertion_devices<'a>(
+    assertion_request: &'a FidoAssertionRequest,
+    devices: impl Iterator<Item = &'a mut FidoDevice>,
+    timeout: Option<Duration>,
+) -> FidoResult<(&'a FidoCredential, AuthenticatorData)> {
+    let get_assertion = |device: &mut FidoDevice| device.get_assertion(assertion_request);
+    request_multiple_devices(devices.map(|device| (device, &get_assertion)), timeout)
+}
+
+/// Will send the `credential_request` to all supplied `devices` and return either the first credential or the last error
+#[cfg(feature = "request_multiple")]
+pub fn make_credential_devices<'a>(
+    credential_request: &'a FidoCredentialRequest,
+    devices: impl Iterator<Item = &'a mut FidoDevice>,
+    timeout: Option<Duration>,
+) -> FidoResult<FidoCredential> {
+    let make_credential = |device: &mut FidoDevice| device.make_credential(credential_request);
+    request_multiple_devices(devices.map(|device| (device, &make_credential)), timeout)
+}