ccm: enable and fix workspace-level lints

ccm/Cargo.toml

@@ -31,3 +31,9 @@ arrayvec = ["aead/arrayvec"]
 bytes = ["aead/bytes"]
 getrandom = ["aead/getrandom"]
 rand_core = ["aead/rand_core"]
+
+[lints]
+workspace = true
+
+[package.metadata.docs.rs]
+all-features = true

ccm/src/lib.rs

@@ -1,11 +1,10 @@
 #![no_std]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 #![doc = include_str!("../README.md")]
 #![doc(
     html_logo_url = "https://raw.githubusercontent.com/RustCrypto/meta/master/logo.svg",
     html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/meta/master/logo.svg"
 )]
-#![deny(unsafe_code)]
-#![warn(missing_docs, rust_2018_idioms)]
 
 //! # Usage
 //!
@@ -102,7 +101,7 @@ use aead::{
 use cipher::{
     Block, BlockCipherEncrypt, BlockSizeUser, InnerIvInit, StreamCipher, StreamCipherSeek,
 };
-use core::marker::PhantomData;
+use core::{fmt, marker::PhantomData};
 use ctr::{Ctr32BE, Ctr64BE, CtrCore};
 use subtle::ConstantTimeEq;
 
@@ -174,7 +173,7 @@ where
     ) -> Result<Tag<C::BlockSize>, Error> {
         let is_ad = !adata.is_empty();
         let l = N::get_l();
-        let flags = 64 * (is_ad as u8) + 8 * M::get_m_tick() + (l - 1);
+        let flags = 64 * u8::from(is_ad) + 8 * M::get_m_tick() + (l - 1);
 
         if buffer.len() > N::get_max_len() {
             return Err(Error);
@@ -186,8 +185,10 @@ where
         b0[1..n].copy_from_slice(nonce);
 
         let cb = b0.len() - n;
+
         // the max len check makes certain that we discard only
         // zero bytes from `b`
+        #[allow(clippy::cast_possible_truncation, reason = "TODO")]
         if cb > 4 {
             let b = (buffer.len() as u64).to_be_bytes();
             b0[n..].copy_from_slice(&b[b.len() - cb..]);
@@ -292,7 +293,7 @@ where
             ctr.apply_keystream_inout(buffer);
         }
 
-        Ok(Tag::try_from(&full_tag[..M::to_usize()]).expect("tag size mismatch"))
+        full_tag[..M::to_usize()].try_into().map_err(|_| Error)
     }
 
     fn decrypt_inout_detached(
@@ -335,6 +336,17 @@ where
     }
 }
 
+impl<C, M, N> fmt::Debug for Ccm<C, M, N>
+where
+    C: BlockSizeUser<BlockSize = U16> + BlockCipherEncrypt,
+    M: ArraySize + TagSize,
+    N: ArraySize + NonceSize,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Ccm").finish_non_exhaustive()
+    }
+}
+
 struct CbcMac<'a, C: BlockCipherEncrypt> {
     cipher: &'a C,
     state: Block<C>,
@@ -378,14 +390,15 @@ where
     }
 }
 
+#[allow(clippy::cast_possible_truncation, reason = "TODO")]
 fn fill_aad_header(adata_len: usize) -> (usize, Array<u8, U16>) {
     debug_assert_ne!(adata_len, 0);
 
     let mut b = Array::<u8, U16>::default();
     let n = if adata_len < 0xFF00 {
         b[..2].copy_from_slice(&(adata_len as u16).to_be_bytes());
         2
-    } else if adata_len <= u32::MAX as usize {
+    } else if u32::try_from(adata_len).is_ok() {
         b[0] = 0xFF;
         b[1] = 0xFE;
         b[2..6].copy_from_slice(&(adata_len as u32).to_be_bytes());

ccm/src/private.rs

@@ -14,7 +14,7 @@ pub trait SealedNonce: Unsigned {
     fn get_max_len() -> usize {
         // a somewhat ugly code to prevent overflow.
         // compiler should be able to completely optimize it out
-        let l = Self::get_l() as u128;
+        let l = u128::from(Self::get_l());
         let v = (1 << (8 * l)) - 1;
         core::cmp::min(v, usize::MAX as u128) as usize
     }

ccm/tests/mod.rs → ccm/tests/ccm.rs

@@ -1,3 +1,5 @@
+//! CCM integration tests.
+
 #![cfg(feature = "alloc")]
 
 use aead::{Aead, AeadInOut, KeyInit, Payload, array::Array};
@@ -13,7 +15,7 @@ fn test_data_len_check() {
     let key = hex!("D7828D13B2B0BDC325A76236DF93CC6B");
     let nonce = hex!("2F1DBD38CE3EDA7C23F04DD650");
 
-    type Cipher = Ccm<aes::Aes128, U10, U13>;
+    type Cipher = Ccm<Aes128, U10, U13>;
     let key = Array(key);
     let nonce = Array(nonce);
     let c = Cipher::new(&key);
@@ -37,7 +39,7 @@ fn sp800_38c_examples() {
             nonce: $nonce:expr, adata: $adata:expr, pt: $pt:expr, ct: $ct:expr,
         ) => {
             let key = Array($key);
-            let c = Ccm::<aes::Aes128, $m, $n>::new(&key);
+            let c = Ccm::<Aes128, $m, $n>::new(&key);
             let nonce = Array($nonce);
             let res = c.encrypt(&nonce, Payload { aad: &$adata, msg: &$pt })
                 .unwrap();
@@ -80,7 +82,9 @@ fn sp800_38c_examples() {
         "),
     );
 
-    let adata = (0..524288 / 8).map(|i| i as u8).collect::<Vec<u8>>();
+    #[allow(clippy::cast_possible_truncation, reason = "TODO")]
+    let adata = (0u32..524288 / 8).map(|i| i as u8).collect::<Vec<u8>>();
+
     check!(
         key, U14, U13,
         nonce: hex!("10111213 14151617 18191a1b 1c"),