ssh-encoding: bytes feature

Adds (optional) support for decoding/encoding `bytes::Bytes` as
`byte[n]`.

ssh-encoding/Cargo.toml

@@ -16,6 +16,7 @@ rust-version = "1.60"
 
 [dependencies]
 base64 = { package = "base64ct", version = "1.4", optional = true }
+bytes = { version = "1", optional = true, default-features = false }
 pem = { package = "pem-rfc7468", version = "0.7", optional = true }
 sha2 = { version = "0.10", optional = true, default-features = false }
 
@@ -26,6 +27,7 @@ hex-literal = "0.4.1"
 alloc = ["base64?/alloc", "pem?/alloc"]
 std = ["alloc", "base64?/std", "pem?/std", "sha2?/std"]
 
+bytes = ["alloc", "dep:bytes"]
 pem = ["base64", "dep:pem"]
 
 [package.metadata.docs.rs]

ssh-encoding/src/decode.rs

@@ -8,6 +8,9 @@ use crate::{reader::Reader, Error, Result};
 #[cfg(feature = "alloc")]
 use alloc::{string::String, vec::Vec};
 
+#[cfg(feature = "bytes")]
+use bytes::Bytes;
+
 #[cfg(feature = "pem")]
 use {crate::PEM_LINE_WIDTH, pem::PemLabel};
 
@@ -177,3 +180,19 @@ impl Decode for Vec<String> {
         })
     }
 }
+
+/// Decodes `Bytes` from `byte[n]` as described in [RFC4251 § 5]:
+///
+/// > A byte represents an arbitrary 8-bit value (octet).  Fixed length
+/// > data is sometimes represented as an array of bytes, written
+/// > `byte[n]`, where n is the number of bytes in the array.
+///
+/// [RFC4251 § 5]: https://datatracker.ietf.org/doc/html/rfc4251#section-5
+#[cfg(feature = "bytes")]
+impl Decode for Bytes {
+    type Error = Error;
+
+    fn decode(reader: &mut impl Reader) -> Result<Self> {
+        Vec::<u8>::decode(reader).map(Into::into)
+    }
+}

ssh-encoding/src/encode.rs

@@ -9,6 +9,9 @@ use core::str;
 #[cfg(feature = "alloc")]
 use alloc::{string::String, vec::Vec};
 
+#[cfg(feature = "bytes")]
+use bytes::Bytes;
+
 #[cfg(feature = "pem")]
 use {
     crate::PEM_LINE_WIDTH,
@@ -249,3 +252,14 @@ impl Encode for Vec<String> {
         Ok(())
     }
 }
+
+#[cfg(feature = "bytes")]
+impl Encode for Bytes {
+    fn encoded_len(&self) -> Result<usize, Error> {
+        self.as_ref().encoded_len()
+    }
+
+    fn encode(&self, writer: &mut impl Writer) -> Result<(), Error> {
+        self.as_ref().encode(writer)
+    }
+}