Add clippy::unwrap_used lint (#515)

Lints for usages of `unwrap()` in the `yubikey` crate (not CLI yet).

Replaces them with `?` or `expect()` as the situation warrants.

src/cccid.rs

@@ -30,7 +30,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-use crate::{Error, Result, YubiKey};
+use crate::{Result, YubiKey};
 use rand_core::{OsRng, RngCore};
 use std::fmt::{self, Debug, Display};
 
@@ -48,6 +48,7 @@ const OBJ_CAPABILITY: u32 = 0x005f_c107;
 ///  - 0xff == Manufacturer ID (dummy)
 ///  - 0x02 == Card type (javaCard)
 ///  - next 14 bytes: card ID
+#[allow(dead_code)]
 const CCC_TMPL: &[u8] = &[
     0xf0, 0x15, 0xa0, 0x00, 0x00, 0x01, 0x16, 0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf1, 0x01, 0x21, 0xf2, 0x01, 0x21, 0xf3, 0x00, 0xf4,
@@ -90,12 +91,7 @@ impl CccId {
     pub fn get(yubikey: &mut YubiKey) -> Result<Self> {
         let txn = yubikey.begin_transaction()?;
         let response = txn.fetch_object(OBJ_CAPABILITY)?;
-
+        Ok(response[..Self::BYTE_SIZE].try_into().map(Self)?)
-        if response.len() != CCC_TMPL.len() {
-            return Err(Error::GenericError);
-        }
-
-        Ok(Self(response[..Self::BYTE_SIZE].try_into().unwrap()))
     }
 
     /// Set Cardholder Capability Container (CCC) ID

src/certificate.rs

@@ -223,12 +223,7 @@ pub(crate) fn write_certificate(
 ) -> Result<()> {
     let object_id = slot.object_id();
 
-    if data.is_none() {
+    if let Some(data) = data {
-        return txn.save_object(object_id, &[]);
-    }
-
-    let data = data.unwrap();
-
         let mut buf = [0u8; CB_OBJ_MAX];
         let mut offset = Tlv::write(&mut buf, TAG_CERT, data)?;
 
@@ -237,6 +232,9 @@ pub(crate) fn write_certificate(
         offset += Tlv::write(&mut buf[offset..], TAG_CERT_LRC, &[])?;
 
         txn.save_object(object_id, &buf[..offset])
+    } else {
+        txn.save_object(object_id, &[])
+    }
 }
 
 pub mod yubikey_signer {

src/chuid.rs

@@ -30,7 +30,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-use crate::{Error, Result, YubiKey};
+use crate::{Result, YubiKey};
 use std::fmt::{self, Debug, Display};
 use uuid::Uuid;
 
@@ -61,6 +61,7 @@ const OBJ_CHUID: u32 = 0x005f_c102;
 /// - 0x35: Exp. Date (hard-coded)
 /// - 0x3e: Signature (hard-coded, empty)
 /// - 0xfe: Error Detection Code (hard-coded)
+#[allow(dead_code)]
 const CHUID_TMPL: &[u8] = &[
     0x30, 0x19, 0xd4, 0xe7, 0x39, 0xda, 0x73, 0x9c, 0xed, 0x39, 0xce, 0x73, 0x9d, 0x83, 0x68, 0x58,
     0x21, 0x08, 0x42, 0x10, 0x84, 0x21, 0xc8, 0x42, 0x10, 0xc3, 0xeb, 0x34, 0x10, 0x00, 0x00, 0x00,
@@ -86,12 +87,13 @@ impl ChuId {
     pub fn fascn(&self) -> [u8; Self::FASCN_SIZE] {
         self.0[CHUID_FASCN_OFFS..(CHUID_FASCN_OFFS + Self::FASCN_SIZE)]
             .try_into()
-            .unwrap()
+            .expect("should be FASCN_SIZE")
     }
 
     /// Return Card UUID/GUID component of CHUID
     pub fn uuid(&self) -> Uuid {
-        Uuid::from_slice(&self.0[CHUID_GUID_OFFS..(CHUID_GUID_OFFS + 16)]).unwrap()
+        Uuid::from_slice(&self.0[CHUID_GUID_OFFS..(CHUID_GUID_OFFS + 16)])
+            .expect("should be UUID-sized")
     }
 
     /// Return expiration date component of CHUID
@@ -99,19 +101,14 @@ impl ChuId {
     pub fn expiration(&self) -> [u8; Self::EXPIRATION_SIZE] {
         self.0[CHUID_EXPIRATION_OFFS..(CHUID_EXPIRATION_OFFS + Self::EXPIRATION_SIZE)]
             .try_into()
-            .unwrap()
+            .expect("should be EXPIRATION_SIZE")
     }
 
     /// Get Cardholder Unique Identifier (CHUID)
     pub fn get(yubikey: &mut YubiKey) -> Result<ChuId> {
         let txn = yubikey.begin_transaction()?;
         let response = txn.fetch_object(OBJ_CHUID)?;
-
+        Ok(response[..Self::BYTE_SIZE].try_into().map(Self)?)
-        if response.len() != CHUID_TMPL.len() {
-            return Err(Error::GenericError);
-        }
-
-        Ok(ChuId(response[..Self::BYTE_SIZE].try_into().unwrap()))
     }
 
     /// Set Cardholder Unique Identifier (CHUID)

src/config.rs

@@ -111,7 +111,7 @@ impl Config {
                     error!("pin timestamp in admin metadata is an invalid size");
                 } else {
                     // TODO(tarcieri): double-check endianness is correct
-                    let pin_last_changed = u32::from_le_bytes(item.try_into().unwrap());
+                    let pin_last_changed = u32::from_le_bytes([item[0], item[1], item[2], item[3]]);
 
                     if pin_last_changed != 0 {
                         config.pin_last_changed =

src/error.rs

@@ -164,6 +164,18 @@ impl Display for Error {
     }
 }
 
+impl From<std::array::TryFromSliceError> for Error {
+    fn from(_: std::array::TryFromSliceError) -> Error {
+        Error::SizeError
+    }
+}
+
+impl From<std::time::SystemTimeError> for Error {
+    fn from(_: std::time::SystemTimeError) -> Error {
+        Error::GenericError
+    }
+}
+
 impl From<pcsc::Error> for Error {
     fn from(err: pcsc::Error) -> Error {
         Error::PcscError { inner: Some(err) }

src/lib.rs

@@ -4,7 +4,14 @@
 )]
 #![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #![forbid(unsafe_code)]
-#![warn(missing_docs, rust_2018_idioms, trivial_casts, unused_qualifications)]
+#![warn(
+    clippy::mod_module_files,
+    clippy::unwrap_used,
+    missing_docs,
+    rust_2018_idioms,
+    unused_lifetimes,
+    unused_qualifications
+)]
 
 // Adapted from yubico-piv-tool:
 // <https://github.com/Yubico/yubico-piv-tool/>

src/mscmap.rs

@@ -140,7 +140,7 @@ impl MsContainer {
         let name_bytes_len = Self::NAME_LEN * 2;
 
         for (i, chunk) in bytes[..name_bytes_len].chunks_exact(2).enumerate() {
-            name[i] = u16::from_le_bytes(chunk.try_into().unwrap());
+            name[i] = u16::from_le_bytes([chunk[0], chunk[1]]);
         }
 
         let mut cert_fingerprint = [0u8; 20];
@@ -150,11 +150,10 @@ impl MsContainer {
             name,
             slot: bytes[name_bytes_len].try_into()?,
             key_spec: bytes[name_bytes_len + 1],
-            key_size_bits: u16::from_le_bytes(
+            key_size_bits: u16::from_le_bytes([
-                bytes[(name_bytes_len + 2)..(name_bytes_len + 4)]
+                bytes[name_bytes_len + 2],
-                    .try_into()
+                bytes[name_bytes_len + 3],
-                    .unwrap(),
+            ]),
-            ),
             flags: bytes[name_bytes_len + 4],
             pin_id: bytes[name_bytes_len + 5],
             associated_echd_container: bytes[name_bytes_len + 6],
@@ -183,7 +182,10 @@ impl MsContainer {
         bytes.push(self.pin_id);
         bytes.push(self.associated_echd_container);
         bytes.extend_from_slice(&self.cert_fingerprint);
-        bytes.as_slice().try_into().unwrap()
+        bytes
+            .as_slice()
+            .try_into()
+            .expect("should be REC_LEN-sized")
     }
 }
 

src/piv.rs

@@ -767,6 +767,7 @@ impl RsaKeyData {
     /// Generates a new RSA key data set from two randomly generated, secret, primes.
     ///
     /// Panics if `secret_p` or `secret_q` are invalid primes.
+    #[allow(clippy::unwrap_used)] // TODO(tarcieri): make fallible and handle errors
     pub fn new(secret_p: &[u8], secret_q: &[u8]) -> Self {
         let p = BigUint::from_bytes_be(secret_p);
         let q = BigUint::from_bytes_be(secret_q);

src/reader.rs

@@ -1,6 +1,6 @@
 //! Support for enumerating available PC/SC card readers.
 
-use crate::{Result, YubiKey};
+use crate::{Error, Result, YubiKey};
 use std::{
     borrow::Cow,
     ffi::CStr,
@@ -43,7 +43,8 @@ impl Context {
         let Self { ctx, reader_names } = self;
 
         let reader_cstrs: Vec<_> = {
-            let c = ctx.lock().unwrap();
+            // TODO(tarcieri): better error?
+            let c = ctx.lock().map_err(|_| Error::GenericError)?;
 
             // ensure PC/SC context is valid
             c.is_valid()?;
@@ -90,7 +91,8 @@ impl<'ctx> Reader<'ctx> {
 
     /// Connect to this reader, returning its `pcsc::Card`.
     pub(crate) fn connect(&self) -> Result<pcsc::Card> {
-        let ctx = self.ctx.lock().unwrap();
+        // TODO(tarcieri): better error?
+        let ctx = self.ctx.lock().map_err(|_| Error::GenericError)?;
         Ok(ctx.connect(self.name, pcsc::ShareMode::Shared, pcsc::Protocols::T1)?)
     }
 }

src/transaction.rs

@@ -96,11 +96,7 @@ impl<'tx> Transaction<'tx> {
             return Err(Error::GenericError);
         }
 
-        if response.data().len() < 3 {
+        Ok(response.data()[..3].try_into().map(Version::new)?)
-            return Err(Error::SizeError);
-        }
-
-        Ok(Version::new(response.data()[..3].try_into().unwrap()))
     }
 
     /// Get YubiKey device serial number.

src/yubikey.rs

@@ -371,7 +371,7 @@ impl YubiKey {
         }
 
         // send a response to the cards challenge and a challenge of our own.
-        let response = mgm_key.decrypt(challenge.data()[4..12].try_into().unwrap());
+        let response = mgm_key.decrypt(challenge.data()[4..12].try_into()?);
 
         let mut data = [0u8; 22];
         data[0] = TAG_DYN_AUTH;
@@ -517,8 +517,7 @@ impl YubiKey {
 
         // TODO(tarcieri): double check this is little endian
         let tnow = SystemTime::now()
-            .duration_since(UNIX_EPOCH)
+            .duration_since(UNIX_EPOCH)?
-            .unwrap()
             .as_secs()
             .to_le_bytes();
 
@@ -648,7 +647,11 @@ impl YubiKey {
             return Err(Error::AuthenticationError);
         }
 
-        Ok(response.data()[4..12].try_into().unwrap())
+        Ok(response
+            .data()
+            .get(4..12)
+            .ok_or(Error::SizeError)?
+            .try_into()?)
     }
 
     /// Verify an auth response.