cipher: use block_buffer::ReadBuffer in StreamCipherCoreWrapper (#1959)

This simplifies the wrapper code and allows to mark the `cipher` crate
with `#![forbid(unsafe_code)]`.

Author: newpavlov

Cargo.lock

@@ -21,4 +21,5 @@ signature = { path = "signature" }
 blobby = { git = "https://github.com/RustCrypto/utils" }
 # https://github.com/RustCrypto/utils/pull/1192
 # https://github.com/RustCrypto/utils/pull/1200
-block-buffer = { git = "https://github.com/RustCrypto/utils" }
+# https://github.com/RustCrypto/utils/pull/1201
+block-buffer = { git = "https://github.com/RustCrypto/utils", branch = "block-buffer/read-buf" }

Cargo.toml

@@ -18,16 +18,18 @@ inout = "0.2.0-rc.4"
 
 # optional dependencies
 blobby = { version = "0.4.0-pre.0", optional = true }
+block-buffer = { version = "0.11.0-rc.4", optional = true}
 zeroize = { version = "1.8", optional = true, default-features = false }
 
 [features]
 alloc = []
 block-padding = ["inout/block-padding"]
+stream-wrapper = ["block-buffer"]
 # Enable random key and IV generation methods
 rand_core = ["crypto-common/rand_core"]
 os_rng = ["crypto-common/os_rng", "rand_core"]
 dev = ["blobby"]
-zeroize = ["dep:zeroize", "crypto-common/zeroize"]
+zeroize = ["dep:zeroize", "crypto-common/zeroize", "block-buffer?/zeroize"]
 
 [package.metadata.docs.rs]
 all-features = true

cipher/Cargo.toml

@@ -57,8 +57,8 @@ macro_rules! stream_cipher_test {
             );
 
             for (i, tv) in TEST_VECTORS.iter().enumerate() {
-                let res = $crate::dev::stream::stream_cipher_test(tv);
-                if Err(reason) = res {
+                let res = $crate::dev::stream::stream_cipher_test::<$cipher>(tv);
+                if let Err(reason) = res {
                     panic!(
                         "\n\
                         Failed test #{i}\n\

cipher/src/dev/stream.rs

@@ -17,6 +17,7 @@
     unused_lifetimes,
     missing_debug_implementations
 )]
+#![forbid(unsafe_code)]
 
 #[cfg(feature = "alloc")]
 extern crate alloc;

cipher/src/lib.rs

@@ -9,13 +9,15 @@ use inout::{InOutBuf, NotEqualError};
 
 mod core_api;
 mod errors;
+#[cfg(feature = "stream-wrapper")]
 mod wrapper;
 
 pub use core_api::{
     StreamCipherBackend, StreamCipherClosure, StreamCipherCore, StreamCipherCounter,
     StreamCipherSeekCore,
 };
 pub use errors::{OverflowError, StreamCipherError};
+#[cfg(feature = "stream-wrapper")]
 pub use wrapper::StreamCipherCoreWrapper;
 
 /// Marker trait for block-level asynchronous stream ciphers