fix: tolerate newer versions

Cargo.toml

@@ -1,12 +1,13 @@
 [package]
 name = "ctap_hmac"
 description = "A Rust implementation of the FIDO2 CTAP protocol, including the HMAC extension"
-version = "0.2.1"
+version = "0.4.5"
 license = "Apache-2.0/MIT"
-homepage = "https://github.com/ArdaXi/ctap/pull/2"
+homepage = "https://github.com/shimunn/ctap"
 repository = "https://github.com/shimunn/ctap"
 authors = ["Arda Xi <arda@ardaxi.com>", "shimun <shimun@shimun.net>"]
 edition = "2018"
+readme = "README.md"
 
 [dependencies]
 rand = "0.6"
@@ -19,5 +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"
-csv-core = "0.1.6"
+[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"];")
+}

examples/hmac.rs

@@ -2,8 +2,8 @@ extern crate ctap_hmac as ctap;
 
 use crypto::digest::Digest;
 use crypto::sha2::Sha256;
-use ctap::extensions::hmac::{FidoHmacCredential, HmacExtension};
+use ctap::extensions::hmac::HmacExtension;
-use ctap_hmac::{AuthenticatorOptions, PublicKeyCredentialRpEntity, PublicKeyCredentialUserEntity};
+use ctap::{FidoAssertionRequestBuilder, FidoCredential, FidoCredentialRequestBuilder};
 use hex;
 use std::env::args;
 use std::io::prelude::*;
@@ -14,43 +14,33 @@ const RP_ID: &str = "ctap_demo";
 
 fn main() -> ctap::FidoResult<()> {
     let mut devices = ctap::get_devices()?;
-    let device_info = &mut devices.next().expect("No authenicator found");
+    let device_info = &mut devices.next().expect("No authenticator found");
     let mut device = ctap::FidoDevice::new(device_info)?;
-    let options = || {
+
-        Some(AuthenticatorOptions {
+    let credential = match args().skip(1).next().map(|h| FidoCredential {
-            uv: false,
-            rk: true,
-        })
-    };
-    let mut credential = match args().skip(1).next().map(|h| FidoHmacCredential {
         id: hex::decode(&h).expect("Invalid credential"),
-        rp_id: RP_ID.into(),
+        public_key: None,
     }) {
         Some(cred) => cred,
         _ => {
-            let rp = PublicKeyCredentialRpEntity {
+            let req = FidoCredentialRequestBuilder::default()
-                id: RP_ID,
+                .rp_id(RP_ID)
-                name: Some("ctap_hmac crate"),
+                .rp_name("ctap_hmac crate")
-                icon: None,
+                .user_name("example")
-            };
+                .uv(false)
-            let user = PublicKeyCredentialUserEntity {
+                .build()
-                id: &[0u8],
+                .unwrap();
-                name: "commandline",
-                icon: None,
-                display_name: None,
-            };
 
             println!("Authorize using your device");
-            let credential: FidoHmacCredential = device
+            let cred = device
-                .make_hmac_credential_full(rp, user, &[0u8; 32], &[], options())
+                .make_hmac_credential(&req)
-                .map(|cred| cred.into())?;
+                .expect("Failed to request credential");
-            println!("Credential: {}\nNote: You can pass this credential as first argument in order to reproduce results", hex::encode(&credential.id));
+            println!("Credential: {}\nNote: You can pass this credential as first argument in order to reproduce results", hex::encode(&cred.id));
-            credential
+            cred
         }
     };
-    let credential = credential;
     print!("Type in your message: ");
-    stdout().flush();
+    stdout().flush().unwrap();
     let mut message = String::new();
     stdin()
         .read_line(&mut message)
@@ -61,14 +51,13 @@ fn main() -> ctap::FidoResult<()> {
     let mut digest = Sha256::new();
     digest.input(&message.as_bytes());
     digest.result(&mut salt);
-    let hash = device
+    let credential = &&credential;
-        .get_hmac_assertion(
+    let request = FidoAssertionRequestBuilder::default()
-            &credential,
+        .rp_id(RP_ID)
-            &salt,
+        .credential(credential)
-            None,
+        .build()
-            None,
+        .unwrap();
-        )?
+    let (_cred, (hash1, _hash2)) = device.get_hmac_assertion(&request, &salt, None)?;
-        .0;
+    println!("Hash: {}", hex::encode(&hash1));
-    println!("Hash: {}", hex::encode(&hash));
     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

@@ -7,6 +7,7 @@
 use cbor_codec::value;
 use cbor_codec::value::Value;
 use cbor_codec::{Config, Decoder, Encoder, GenericDecoder, GenericEncoder};
+use cbor::skip::Skip;
 
 use byteorder::{BigEndian, ByteOrder, ReadBytesExt, WriteBytesExt};
 use failure::ResultExt;
@@ -38,7 +39,7 @@ impl<'a> Request<'a> {
         }
     }
 
-    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(MakeCredentialResponse::decode(reader)?)
@@ -277,7 +278,7 @@ 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(CborErrorCode::from(status)))?
@@ -304,7 +305,7 @@ impl GetInfoResponse {
                         response.pin_protocols.push(decoder.u8()?);
                     }
                 }
-                _ => continue,
+                _ => decoder.skip()?,
             }
         }
         Ok(response)
@@ -423,7 +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)
@@ -595,14 +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
                 }
             }
         }
@@ -700,15 +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")?;
@@ -718,6 +753,10 @@ impl AuthenticatorOptions {
             encoder.text("uv")?;
             encoder.bool(true)?;
         }
+        if self.up {
+            encoder.text("up")?;
+            encoder.bool(true)?;
+        }
         Ok(())
     }
 }

src/error.rs

@@ -5,8 +5,8 @@
 // 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::{DecodeError, EncodeError};
-use csv_core::{ReadFieldResult, Reader};
 use failure::_core::fmt::{Error, Formatter};
+use failure::_core::option::Option;
 use failure::{Backtrace, Context, Fail};
 use std::fmt;
 use std::fmt::Display;
@@ -19,10 +19,38 @@ 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.")]
@@ -45,7 +73,9 @@ 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: {}", _0)]
     CborError(CborErrorCode),
@@ -112,58 +142,24 @@ impl From<u8> for CborErrorCode {
 
 impl Display for CborErrorCode {
     fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error> {
-        let messages = include_str!("ctap_error_codes.csv");
+        if let Some((code, _name, desc)) = self.detail() {
-        let mut rdr = Reader::new();
-        let mut bytes = messages.as_bytes();
-        let mut col: usize = 0;
-        let mut row: usize = 0;
-        let mut correct_row: bool = false;
-        let mut field = [0u8; 1024];
-        let mut name: Option<String> = None;
-        let mut desc: Option<String> = None;
-        loop {
-            let (result, nin, read) = rdr.read_field(&bytes, &mut field);
-            bytes = &bytes[nin..];
-            match result {
-                ReadFieldResult::InputEmpty => {}
-                ReadFieldResult::OutputFull => panic!("field too large"),
-                ReadFieldResult::Field { record_end } => {
-                    let text = String::from_utf8(field[..read].iter().cloned().collect()).unwrap();
-                    if row > 0 {
-                        match col {
-                            0 if i64::from_str_radix(&text[2..], 16)
-                                .expect("malformed ctap_error_codes.csv")
-                                == self.0 as i64 =>
-                            {
-                                correct_row = true
-                            }
-                            1 | 2 if correct_row => {
-                                if let Some(_) = name {
-                                    desc = Some(text);
-                                    break;
-                                } else {
-                                    name = Some(text);
-                                }
-                            }
-                            _ => (),
-                        }
-                    }
-                    col += 1;
-                    if record_end {
-                        col = 0;
-                        row += 1;
-                    }
-                }
-                ReadFieldResult::End => break,
-            }
-        }
-        if let Some((code, _name, desc)) =
-            name.and_then(|name| desc.map(|desc| (self.0, name, desc)))
-        {
             write!(f, "CborError: 0x{:x?}: {}", code, desc)?;
         } else {
-            write!(f, "CborError: 0x{:x?}", self.0)?;
+            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

@@ -1,6 +1,4 @@
-use crate::{
+use crate::{FidoAssertionRequest, FidoAssertionRequestBuilder, FidoCredentialRequest};
-    cbor, AuthenticatorOptions, PublicKeyCredentialRpEntity, PublicKeyCredentialUserEntity,
-};
 use crate::{FidoCredential, FidoDevice, FidoErrorKind, FidoResult};
 use cbor_codec::value::{Bytes, Int, Key, Text, Value};
 use cbor_codec::Encoder;
@@ -13,21 +11,6 @@ use rust_crypto::sha2::Sha256;
 use std::collections::BTreeMap;
 use std::io::Cursor;
 
-#[derive(Debug, Clone)]
-pub struct FidoHmacCredential {
-    pub id: Vec<u8>,
-    pub rp_id: String,
-}
-
-impl From<FidoCredential> for FidoHmacCredential {
-    fn from(cred: FidoCredential) -> Self {
-        FidoHmacCredential {
-            id: cred.id,
-            rp_id: cred.rp_id,
-        }
-    }
-}
-
 pub trait HmacExtension {
     fn extension_name() -> &'static str {
         "hmac-secret"
@@ -51,17 +34,11 @@ pub trait HmacExtension {
 
     fn get_data(&mut self, salt: &[u8; 32], salt2: Option<&[u8; 32]>) -> FidoResult<Value>;
 
-    /// Convenience function to create an credential with default rp_id and user_name
+    /// 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) -> FidoResult<FidoHmacCredential>;
+    fn make_hmac_credential(
-
-    fn make_hmac_credential_full(
         &mut self,
-        rp: cbor::PublicKeyCredentialRpEntity,
+        request: &FidoCredentialRequest,
-        user: cbor::PublicKeyCredentialUserEntity,
-        client_data_hash: &[u8],
-        exclude_list: &[cbor::PublicKeyCredentialDescriptor],
-        options: Option<cbor::AuthenticatorOptions>,
     ) -> FidoResult<FidoCredential>;
 
     /// Request an assertion from the authenticator for a given credential and salt(s).
@@ -74,19 +51,19 @@ pub trait HmacExtension {
     /// provided, and will fail if a PIN is required but not provided or if the
     /// device returns malformed data.
     ///
-    fn get_hmac_assertion(
+    fn get_hmac_assertion<'a: 'b, 'b>(
         &mut self,
-        credential: &FidoHmacCredential,
+        assertion: &FidoAssertionRequest<'a, 'b>,
         salt: &[u8; 32],
         salt2: Option<&[u8; 32]>,
-        options: Option<AuthenticatorOptions>,
+    ) -> FidoResult<(&'a FidoCredential, ([u8; 32], Option<[u8; 32]>))>;
-    ) -> FidoResult<([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,
-        credential: &FidoHmacCredential,
+        rp_id: &str,
+        credential: &FidoCredential,
         input: &[u8],
     ) -> FidoResult<[u8; 32]> {
         let mut salt = [0u8; 32];
@@ -94,12 +71,15 @@ pub trait HmacExtension {
         digest.input(input);
         digest.result(&mut salt);
         self.get_hmac_assertion(
-            credential,
+            &FidoAssertionRequestBuilder::default()
+                .rp_id(rp_id)
+                .credential(&credential)
+                .build()
+                .unwrap(),
             &salt,
             None,
-            Some(AuthenticatorOptions { uv: true, rk: true }),
         )
-        .map(|secret| secret.0)
+        .map(|(_cred, secret)| secret.0)
     }
 }
 
@@ -156,94 +136,40 @@ impl HmacExtension for FidoDevice {
         Ok(Value::Map(map))
     }
 
-    fn make_hmac_credential(&mut self) -> FidoResult<FidoHmacCredential> {
+    fn make_hmac_credential(
-        let rp = PublicKeyCredentialRpEntity {
-            id: "hmac",
-            name: None,
-            icon: None,
-        };
-        let user = PublicKeyCredentialUserEntity {
-            id: &[0u8],
-            name: "commandline",
-            icon: None,
-            display_name: None,
-        };
-        let options = Some(AuthenticatorOptions {
-            uv: true,
-            rk: false,
-        });
-
-        self.make_hmac_credential_full(rp, user, &[0u8; 32], &[], options)
-            .map(|cred| cred.into())
-    }
-
-    fn make_hmac_credential_full(
         &mut self,
-        rp: cbor::PublicKeyCredentialRpEntity,
+        request: &FidoCredentialRequest,
-        user: cbor::PublicKeyCredentialUserEntity,
-        client_data_hash: &[u8],
-        exclude_list: &[cbor::PublicKeyCredentialDescriptor],
-        options: Option<cbor::AuthenticatorOptions>,
     ) -> FidoResult<FidoCredential> {
-        self.make_credential_full(
+        let mut request = request.clone();
-            rp,
+        request.rk = true;
-            user,
+        request.extension_data.insert(
-            client_data_hash,
+            <Self as HmacExtension>::extension_name(),
-            exclude_list,
+            <Self as HmacExtension>::extension_input(),
-            &[(
+        );
-                <Self as HmacExtension>::extension_name(),
+        self.make_credential(&request)
-                <Self as HmacExtension>::extension_input(),
-            )],
-            options,
-        )
     }
 
-    fn get_hmac_assertion(
+    fn get_hmac_assertion<'a: 'b, 'b>(
         &mut self,
-        credential: &FidoHmacCredential,
+        request: &FidoAssertionRequest<'a, 'b>,
         salt: &[u8; 32],
         salt2: Option<&[u8; 32]>,
-        options: Option<AuthenticatorOptions>,
+    ) -> FidoResult<(&'a FidoCredential, ([u8; 32], Option<[u8; 32]>))> {
-    ) -> FidoResult<([u8; 32], Option<[u8; 32]>)> {
-        let client_data_hash = [0u8; 32];
         while self.shared_secret.is_none() {
             self.init_shared_secret()?;
         }
-        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 ext_data: Value = self.get_data(salt, salt2)?;
-        let allow_list = [cbor::PublicKeyCredentialDescriptor {
+        let mut request = request.clone();
-            cred_type: String::from("public-key"),
+        request
-            id: credential.id.clone(),
+            .extension_data
-        }];
+            .insert(<Self as HmacExtension>::extension_name(), &ext_data);
-        let request = cbor::GetAssertionRequest {
+
-            rp_id: &credential.rp_id,
+        let (cred, auth_data) = self.get_assertion(&request)?;
-            client_data_hash: &client_data_hash,
-            allow_list: &allow_list,
-            extensions: &[(<Self as HmacExtension>::extension_name(), &ext_data)],
-            options: options,
-            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)?,
-        };
         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 response
+        let hmac_secret_enc = match auth_data
-            .auth_data
             .extensions
             .get(<Self as HmacExtension>::extension_name())
             .ok_or(FidoErrorKind::CborDecode)?
@@ -270,6 +196,11 @@ impl HmacExtension for FidoDevice {
         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..]);
-        Ok((hmac_secret_0, salt2.map(|_| hmac_secret_1)))
+        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/lib.rs

@@ -9,29 +9,31 @@
 //! # 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(())
 //! # }
 
@@ -43,6 +45,8 @@ extern crate rand;
 extern crate failure_derive;
 #[macro_use]
 extern crate num_derive;
+#[macro_use]
+extern crate derive_builder;
 extern crate byteorder;
 extern crate cbor as cbor_codec;
 extern crate crypto as rust_crypto;
@@ -57,6 +61,7 @@ pub mod extensions;
 mod hid_common;
 mod hid_linux;
 mod packet;
+mod util;
 
 use std::cmp;
 use std::fs;
@@ -64,16 +69,16 @@ use std::io::{Cursor, Write};
 use std::u16;
 use std::u8;
 
-pub use self::cbor::{
+use self::cbor::{AuthenticatorOptions, PublicKeyCredentialDescriptor};
-    AuthenticatorOptions, PublicKeyCredentialDescriptor, PublicKeyCredentialRpEntity,
-    PublicKeyCredentialUserEntity,
-};
 pub use self::error::*;
 use self::hid_linux as hid;
 use self::packet::CtapCommand;
+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];
 
@@ -86,16 +91,13 @@ pub fn get_devices() -> FidoResult<impl Iterator<Item = hid::DeviceInfo>> {
 }
 
 /// 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,
@@ -107,6 +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
@@ -146,14 +287,14 @@ 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)?
         }
         // Require pin protocol version 1, only if pin-protocol is supported at all
         if !response
             .pin_protocols
             .iter()
-            .fold(true, |supported, ver| *ver == 1 && supported)
+            .any(|ver| *ver == 1) && response.pin_protocols.len() > 0
         {
             Err(FidoErrorKind::DeviceUnsupported)?
         }
@@ -184,6 +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
@@ -216,88 +362,72 @@ impl FidoDevice {
         }
     }
 
-    /// Request a new credential from the authenticator. The `rp_id` should be
+    pub fn cancel_handle(&mut self) -> FidoResult<FidoCancelHandle> {
-    /// a stable string used to identify the party for whom the credential is
+        Ok(self
-    /// created, for convenience it will be returned with the credential.
+            .device
-    /// `user_id` and `user_name` are not required when requesting attestations
+            .try_clone()
-    /// but they MAY be displayed to the user and MAY be stored on the device
+            .map(|device| FidoCancelHandle {
-    /// to be returned with an attestation if the device supports this.
+                device,
-    /// `client_data_hash` SHOULD be a SHA256 hash of provided `client_data`,
+                packet_size: self.packet_size,
-    /// this is only used to verify the attestation provided by the
+                channel_id: self.channel_id,
-    /// authenticator. When not implementing WebAuthN this can be any random
+            })
-    /// 32-byte array.
+            .context(FidoErrorKind::Io)?)
-    ///
+    }
-    /// 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,
+        request: &FidoCredentialRequest<'_>,
-        user_id: &[u8],
-        user_name: &str,
-        client_data_hash: &[u8],
     ) -> FidoResult<FidoCredential> {
-        //TODO: implement all options: https://fidoalliance.org/specs/fido-v2.0-ps-20190130/fido-client-to-authenticator-protocol-v2.0-ps-20190130.html#authenticatorMakeCredential
         let rp = cbor::PublicKeyCredentialRpEntity {
-            id: rp_id,
+            id: request.rp_id,
-            name: None,
+            name: request.rp_name,
-            icon: None,
+            icon: request.rp_icon_url,
         };
         let user = cbor::PublicKeyCredentialUserEntity {
-            id: user_id,
+            id: request.user_id,
-            name: user_name,
+            name: request.user_name.unwrap_or(""),
-            icon: None,
+            icon: request.user_icon_url,
-            display_name: None,
+            display_name: request.user_display_name,
         };
 
         let options = Some(AuthenticatorOptions {
-            uv: true,
+            up: false,
-            rk: false,
+            uv: request.uv,
+            rk: request.rk,
         });
-        self.make_credential_full(rp, user, client_data_hash, &[], &[], options)
-    }
-
-    /// 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_full(
-        &mut self,
-        rp: cbor::PublicKeyCredentialRpEntity,
-        user: cbor::PublicKeyCredentialUserEntity,
-        client_data_hash: &[u8],
-        exclude_list: &[cbor::PublicKeyCredentialDescriptor],
-        extensions: &[(&str, &cbor_codec::value::Value)],
-        options: Option<cbor::AuthenticatorOptions>,
-    ) -> FidoResult<FidoCredential> {
         if self.needs_pin && self.pin_token.is_none() {
             Err(FidoErrorKind::PinRequired)?
         }
-        if client_data_hash.len() != 32 {
+        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(&client_data_hash));
+            .map(|token| token.auth(&request.client_data_hash));
-        let rp_id = rp.id.to_owned();
         let request = cbor::MakeCredentialRequest {
-            client_data_hash,
+            client_data_hash: request.client_data_hash,
             rp,
             user,
             pub_key_cred_params: &pub_key_cred_params,
-            exclude_list: exclude_list,
+            exclude_list: &request
-            extensions: extensions,
+                .exclude_list
-            options: options,
+                .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)),
         };
@@ -315,85 +445,102 @@ impl FidoDevice {
         .bytes();
         Ok(FidoCredential {
             id: response.auth_data.attested_credential_data.credential_id,
-            rp_id: rp_id,
+            public_key: Some(Vec::from(&public_key[..])),
-            public_key: Vec::from(&public_key[..]),
         })
     }
 
-    /// Request an assertion from the authenticator for a given credential.
+    /// 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 signed and verified as part of the attestation. When not
+    /// this is only used to verify the attestation provided by the
-    /// implementing WebAuthN this can be any random 32-byte array.
+    /// authenticator. When not implementing WebAuthN this can be any random
+    /// 32-byte array.
     ///
-    /// This method will return whether the assertion matches the credential
+    /// This method will fail if a PIN is required but the device is not
-    /// provided, and will fail if a PIN is required but not provided or if the
+    /// unlocked or if the device returns malformed data.
-    /// device returns malformed data.
+    pub fn get_assertion<'a, 'b>(
-    pub fn get_assertion(
         &mut self,
-        credential: &FidoCredential,
+        assertion: &FidoAssertionRequest<'a, 'b>,
-        client_data_hash: &[u8],
+    ) -> FidoResult<(&'a FidoCredential, AuthenticatorData)> {
-    ) -> FidoResult<bool> {
+        while self.shared_secret.is_none() {
-        self.get_assertion_multiple(&[credential], client_data_hash)
+            self.init_shared_secret()?;
-    }
+        }
-
-    pub fn get_assertion_multiple(
-        &mut self,
-        credentials: &[&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 {
+        if assertion.client_data_hash.len() != 32 {
             Err(FidoErrorKind::CborEncode)?
         }
         let pin_auth = self
             .pin_token
             .as_ref()
-            .map(|token| token.auth(&client_data_hash));
+            .map(|token| token.auth(&assertion.client_data_hash));
-        let allow_list = credentials
+        let request = GetAssertionRequest {
-            .iter()
+            rp_id: assertion.rp_id,
-            .map(|cred| cbor::PublicKeyCredentialDescriptor {
+            client_data_hash: assertion.client_data_hash,
-                cred_type: String::from("public-key"),
+            allow_list: &assertion
-                id: cred.id.clone(),
+                .credentials
-            })
+                .iter()
-            .collect::<Vec<_>>();
+                .map(|cred| PublicKeyCredentialDescriptor {
-        let request = cbor::GetAssertionRequest {
+                    cred_type: "public-key".into(),
-            rp_id: &credentials[0].rp_id,
+                    id: cred.id.clone(),
-            client_data_hash: client_data_hash,
+                })
-            allow_list: &allow_list,
+                .collect::<Vec<_>>()[..],
-            extensions: Default::default(),
+            extensions: &assertion
-            options: Some(cbor::AuthenticatorOptions {
+                .extension_data
-                rk: false,
+                .iter()
-                uv: true,
+                .map(|(name, data)| (*name, *data))
+                .collect::<Vec<_>>()[..],
+            options: Some(AuthenticatorOptions {
+                rk: assertion.rk,
+                uv: assertion.uv,
+                up: assertion.up,
             }),
-            pin_auth,
+            pin_auth: 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(credentials
+        let credential = assertion
+            .credentials
             .iter()
-            .filter(|cred| {
+            .flat_map(|cred| {
                 response
                     .credential
                     .as_ref()
-                    .map(|cred2| cred2.id == cred.id)
+                    .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
+                }
             })
-            .map(|cred| {
+            .ok_or(FidoError::from(FidoErrorKind::VerifySignature))
-                crypto::verify_signature(
+            .map(|cred| (cred, response.auth_data))
-                    &cred.public_key,
-                    &client_data_hash,
-                    &response.auth_data_bytes,
-                    &response.signature,
-                )
-            })
-            .filter(|pass| *pass)
-            .next()
-            .unwrap_or(false))
     }
 
     fn cbor(&mut self, request: cbor::Request) -> FidoResult<cbor::Response> {

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)
+}