simplify byte encodings, use prefixes for crypto data types

README.md

@@ -82,6 +82,30 @@ Terms can be interpreted in a number of different ways, depending on the context
 
 Terms further have mappings as different data types:
 
-- BYTES: if the term maps as a STRING, decode it using base64
 - INT: if the term maps as a STRING, decode it as an integer written in decimal notation
+- BYTES: if the term maps as a STRING, decode it using base64. Since a STRING cannot be empty, the string `-` is used to represent an empty byte string.
+- Cryptographic data types (see below)
+
+## Cryptographic data types
+
+Cryptographic values such as keys, hashes, signatures, etc. are encoded
+as STRING with a prefix indicating the algorithm used, followed by ":",
+followed by the base64-encoded value.
+
+Prefixes are as follows:
+
+- `pk.box:` public key for NaCl's box API
+- `sk.box:` secret key for NaCl's box API
+- `sk.sbox:` secret key for NaCl's secretbox API
+- `h.sha256:` sha256 hash
+- `h.sha512:` sha512 hash
+- `h.sha3:` sha3 hash
+- `h.b2:` blake2b hash
+- `h.b3:` blake3 hash
+- `sig.ed25519:` ed25519 signature
+- `pk.ed25519:` ed25519 public signing key
+- `sk.ed25519:` ed25519 secret signing key
+
+More can be added.
+
 - HASH, PUBKEY, SECKEY, SIGNATURE, ENCKEY, DECKEY, SYMKEY: a bunch of things that interpret BYTES as specific cryptographic items

src/crypto/mod.rs

@@ -1,48 +1,156 @@
 //! Helpers to use cryptographic data types in nettext
 
+pub use dryoc::types::Bytes;
 pub use dryoc::*;
 
-use dryoc::types::{Bytes, StackByteArray};
+use crate::dec;
-
 use crate::enc;
 
-pub type SigningKeyPair = sign::SigningKeyPair<sign::PublicKey, sign::SecretKey>;
+const BM_HASH: &str = "h.b2";
 
-impl<const N: usize> enc::Encode for StackByteArray<N> {
+const BM_SIGNATURE: &str = "sig.ed25519";
+const BM_SIGN_KEYPAIR: &str = "sk.ed25519";
+const BM_SIGN_PUBKEY: &str = "pk.ed25519";
+
+// ---- types ----
+
+#[derive(Eq, PartialEq, Clone, Debug)]
+pub struct Hash(pub generichash::Hash);
+
+#[derive(Eq, PartialEq, Clone, Debug)]
+pub struct Signature(pub sign::Signature);
+#[derive(Eq, PartialEq, Clone, Debug)]
+pub struct SigningPublicKey(pub sign::PublicKey);
+#[derive(PartialEq, Clone, Debug)]
+pub struct SigningKeyPair(pub sign::SigningKeyPair<sign::PublicKey, sign::SecretKey>);
+
+impl SigningKeyPair {
+    /// Return the public key of this keypair
+    pub fn public_key(&self) -> SigningPublicKey {
+        SigningPublicKey(self.0.public_key.clone())
+    }
+}
+
+// ---- encoding ----
+
+impl enc::Encode for Hash {
     fn term(&self) -> enc::Result<'_> {
-        Ok(enc::bytes(self.as_slice()))
+        enc::marked_bytes(BM_HASH, self.0.as_slice())
     }
 }
 
-impl enc::Encode for sign::SigningKeyPair<sign::PublicKey, sign::SecretKey> {
+impl enc::Encode for Signature {
     fn term(&self) -> enc::Result<'_> {
-        Ok(enc::bytes(self.secret_key.as_slice()))
+        enc::marked_bytes(BM_SIGNATURE, self.0.as_slice())
     }
 }
 
-// ---- helpers ----
+impl enc::Encode for SigningPublicKey {
+    fn term(&self) -> enc::Result<'_> {
+        enc::marked_bytes(BM_SIGN_PUBKEY, self.0.as_slice())
+    }
+}
+
+impl enc::Encode for SigningKeyPair {
+    fn term(&self) -> enc::Result<'_> {
+        enc::marked_bytes(BM_SIGN_KEYPAIR, self.0.secret_key.as_slice())
+    }
+}
+
+// ---- calculating hashes, signatures, etc ----
 
 /// Compute the hash of a payload with default dryoc parameters and optionnal key
-pub fn compute_hash(bytes: &[u8], key: Option<&[u8; 32]>) -> generichash::Hash {
+pub fn compute_hash(bytes: &[u8], key: Option<&[u8; 32]>) -> Hash {
-    generichash::GenericHash::hash_with_defaults(bytes, key).unwrap()
+    Hash(generichash::GenericHash::hash_with_defaults(bytes, key).unwrap())
+}
+
+/// Generate a new signing keypair
+pub fn gen_signing_keypair() -> SigningKeyPair {
+    SigningKeyPair(sign::SigningKeyPair::gen_with_defaults())
 }
 
 /// Compute the ed25519 signature of a message using a secret key
-pub fn compute_signature(message: &[u8], secret_key: &sign::SecretKey) -> sign::Signature {
+pub fn compute_signature(message: &[u8], keypair: &SigningKeyPair) -> Signature {
-    SigningKeyPair::from_secret_key(secret_key.clone())
+    Signature(
+        keypair
+            .0
             .sign_with_defaults(message)
             .unwrap()
             .into_parts()
-        .0
+            .0,
+    )
 }
 
 /// Verify the ed25519 signature of a message using a public key
 pub fn verify_signature(
-    signature: &sign::Signature,
+    signature: &Signature,
     message: &[u8],
-    public_key: &sign::PublicKey,
+    public_key: &SigningPublicKey,
 ) -> bool {
-    sign::SignedMessage::from_parts(signature.clone(), message)
+    sign::SignedMessage::from_parts(signature.0.clone(), message)
-        .verify(public_key)
+        .verify(&public_key.0)
         .is_ok()
 }
+
+// ---- decode helpers ----
+
+pub trait CryptoDec {
+    /// Try to interpret this string as a Blake2b512 digest
+    /// (32-bytes base64 encoded, prefixed by `h.b2:`)
+    ///
+    /// Example:
+    ///
+    /// ```
+    /// use nettext::dec::decode;
+    /// use nettext::crypto::{compute_hash, CryptoDec};
+    ///
+    /// let term = decode(b"{
+    ///     message = hello;
+    ///     hash = h.b2:Mk3PAn3UowqTLEQfNlol6GsXPe-kuOWJSCU0cbgbcs8;
+    /// }").unwrap();
+    /// let [msg, hash] = term.dict_of(["message", "hash"], false).unwrap();
+    /// let expected_hash = compute_hash(msg.raw(), None);
+    /// assert_eq!(hash.hash().unwrap(), expected_hash);
+    /// ```
+    fn hash(&self) -> Result<Hash, dec::TypeError>;
+
+    /// Try to interpret this string as an ed25519 signature
+    /// (64 bytes base64 encoded, prefixed by `sig.ed25519:`)
+    fn signature(&self) -> Result<Signature, dec::TypeError>;
+
+    /// Try to interpret this string as an ed25519 keypair
+    /// (64 bytes base64 encoded, prefixed by `sk.ed25519:`)
+    fn keypair(&self) -> Result<SigningKeyPair, dec::TypeError>;
+
+    /// Try to interpret this string as an ed25519 public key
+    /// (32 bytes base64 encoded, prefixed by `pk.ed25519:`)
+    fn public_key(&self) -> Result<SigningPublicKey, dec::TypeError>;
+}
+
+impl<'a, 'b> CryptoDec for dec::Term<'a, 'b> {
+    fn hash(&self) -> Result<Hash, dec::TypeError> {
+        Ok(Hash(generichash::Hash::from(
+            self.marked_bytes_exact(BM_HASH)?,
+        )))
+    }
+
+    /// Try to interpret this string as an ed25519 signature (64 bytes base64 encoded)
+    fn signature(&self) -> Result<Signature, dec::TypeError> {
+        Ok(Signature(sign::Signature::from(
+            self.marked_bytes_exact(BM_SIGNATURE)?,
+        )))
+    }
+
+    fn keypair(&self) -> Result<SigningKeyPair, dec::TypeError> {
+        let secret_key = sign::SecretKey::from(self.marked_bytes_exact(BM_SIGN_KEYPAIR)?);
+        Ok(SigningKeyPair(sign::SigningKeyPair::from_secret_key(
+            secret_key,
+        )))
+    }
+
+    fn public_key(&self) -> Result<SigningPublicKey, dec::TypeError> {
+        Ok(SigningPublicKey(sign::PublicKey::from(
+            self.marked_bytes_exact(BM_SIGN_PUBKEY)?,
+        )))
+    }
+}

src/dec/error.rs

@@ -8,6 +8,9 @@ pub enum TypeError {
     /// The term could not be decoded in the given type
     #[error(display = "Not a {}", _0)]
     WrongType(&'static str),
+    /// The term did not have the correct marker
+    #[error(display = "Byte marker was not {}", _0)]
+    WrongMarker(&'static str),
 
     /// The term is not an array of the requested length
     #[error(display = "Expected {} items, got {}", _0, _1)]

src/dec/mod.rs

@@ -5,9 +5,6 @@ mod error;
 
 use std::collections::HashMap;
 
-#[cfg(any(feature = "dryoc"))]
-use crate::crypto;
-
 use crate::debug;
 
 pub use decode::*;
@@ -420,7 +417,7 @@ impl<'a, 'b> Term<'a, 'b> {
         };
         match self.0.mkref() {
             AnyTerm::Str(encoded) => {
-                if encoded == b"." {
+                if encoded == b"-" {
                     Ok(vec![])
                 } else {
                     decode(encoded)
@@ -442,68 +439,40 @@ impl<'a, 'b> Term<'a, 'b> {
     }
 
     /// Try to interpret this string as base64-encoded bytes,
-    /// with an exact length.
+    /// with a marker prefix and an exact byte length.
+    /// This is typically used for cryptographic data types such as hashes,
+    /// keys, signatures, ...
     ///
     /// Example:
     ///
     /// ```
     /// use nettext::dec::decode;
     ///
-    /// let term = decode(b"aGVsbG8sIHdvcmxkIQ").unwrap();
+    /// let term = decode(b"test:aGVsbG8sIHdvcmxkIQ").unwrap();
-    /// assert_eq!(&term.bytes_exact::<13>().unwrap(), b"hello, world!");
+    /// assert_eq!(&term.marked_bytes_exact::<13>("test").unwrap(), b"hello, world!");
     /// ```
-    pub fn bytes_exact<const N: usize>(&self) -> Result<[u8; N], TypeError> {
+    pub fn marked_bytes_exact<const N: usize>(
-        let bytes = self.bytes()?;
+        &self,
+        marker: &'static str,
+    ) -> Result<[u8; N], TypeError> {
+        let mkr = marker.as_bytes();
+        match &self.0 {
+            AnyTerm::Str(s)
+                if s.len() >= mkr.len() + 2 && &s[..mkr.len()] == mkr && s[mkr.len()] == b':' =>
+            {
+                let bytes = match &s[mkr.len() + 1..] {
+                    b"-" => vec![],
+                    bytes => base64::decode_config(bytes, base64::URL_SAFE_NO_PAD)
+                        .map_err(|_| TypeError::WrongType("BYTES"))?,
+                };
                 let bytes_len = bytes.len();
                 bytes
                     .try_into()
                     .map_err(|_| TypeError::WrongLength(bytes_len, N))
             }
+            AnyTerm::Str(_) => Err(TypeError::WrongMarker(marker)),
+            _ => Err(TypeError::WrongType("BYTES")),
         }
-
-// ---- CRYPTO HELPERS ----
-
-#[cfg(feature = "dryoc")]
-impl<'a, 'b> Term<'a, 'b> {
-    /// Try to interpret this string as a Blake2b512 digest (32-bytes base64 encoded)
-    ///
-    /// Example:
-    ///
-    /// ```
-    /// use nettext::dec::decode;
-    /// use nettext::crypto::generichash::GenericHash;
-    ///
-    /// let term = decode(b"{
-    ///     message = hello;
-    ///     hash = Mk3PAn3UowqTLEQfNlol6GsXPe-kuOWJSCU0cbgbcs8;
-    /// }").unwrap();
-    /// let [msg, hash] = term.dict_of(["message", "hash"], false).unwrap();
-    /// let expected_hash = GenericHash::hash_with_defaults(msg.raw(), None::<&Vec<u8>>).unwrap();
-    /// assert_eq!(hash.hash().unwrap(), expected_hash);
-    /// ```
-    pub fn hash(&self) -> Result<crypto::generichash::Hash, TypeError> {
-        Ok(crypto::generichash::Hash::from(self.bytes_exact()?))
-    }
-
-    /// Try to interpret this string as an ed25519 keypair (64 bytes base64 encoded)
-    pub fn keypair(&self) -> Result<crypto::SigningKeyPair, TypeError> {
-        let secret_key = crypto::sign::SecretKey::from(self.bytes_exact()?);
-        Ok(crypto::SigningKeyPair::from_secret_key(secret_key))
-    }
-
-    /// Try to interpret this string as an ed25519 public key (32 bytes base64 encoded)
-    pub fn public_key(&self) -> Result<crypto::sign::PublicKey, TypeError> {
-        Ok(crypto::sign::PublicKey::from(self.bytes_exact()?))
-    }
-
-    /// Try to interpret this string as an ed25519 secret key (32 bytes base64 encoded)
-    pub fn secret_key(&self) -> Result<crypto::sign::SecretKey, TypeError> {
-        Ok(crypto::sign::SecretKey::from(self.bytes_exact()?))
-    }
-
-    /// Try to interpret this string as an ed25519 signature (64 bytes base64 encoded)
-    pub fn signature(&self) -> Result<crypto::sign::Signature, TypeError> {
-        Ok(crypto::sign::Signature::from(self.bytes_exact()?))
     }
 }
 

src/enc/mod.rs

@@ -22,9 +22,9 @@ mod error;
 use std::borrow::{Borrow, Cow};
 use std::collections::HashMap;
 
-use crate::*;
 use crate::dec::{self, decode};
-use crate::{is_string_char, is_whitespace, BytesEncoding};
+use crate::*;
+use crate::{is_string_char, is_whitespace};
 
 pub use error::Error;
 
@@ -100,41 +100,36 @@ pub fn raw(bytes: &[u8]) -> Result<'_> {
 /// Term corresponding to a byte slice,
 /// encoding using base64 url-safe encoding without padding.
 /// Since empty strings are not possible in nettext,
-/// an empty byte string is encoded as an empty list (`[]`).
+/// an empty byte string is encoded as the special string `-`.
 ///
 /// Example:
 ///
 /// ```
 /// use nettext::enc::*;
 ///
+/// assert_eq!(bytes(b"").encode(), b"-");
 /// assert_eq!(bytes(b"hello, world!").encode(), b"aGVsbG8sIHdvcmxkIQ");
 /// ```
 pub fn bytes(bytes: &[u8]) -> Term<'static> {
-    bytes_format(bytes, BytesEncoding::Base64 { split: false })
+    if bytes.is_empty() {
+        Term(T::Str(b"-"))
+    } else {
+        Term(T::OwnedStr(
+            base64::encode_config(bytes, base64::URL_SAFE_NO_PAD).into_bytes(),
+        ))
+    }
 }
 
 /// Same as `bytes()`, but splits the byte slice in 48-byte chunks
 /// and encodes each chunk separately, putting them in a sequence of terms.
-/// Usefull for long byte slices to have cleaner representations,
+/// Usefull for long byte slices to have cleaner representations.
-/// mainly usefull for dictionnary keys.
 pub fn bytes_split(bytes: &[u8]) -> Term<'static> {
-    bytes_format(bytes, BytesEncoding::Base64 { split: true })
+    if bytes.is_empty() {
-}
+        Term(T::Str(b"-"))
-
+    } else {
-pub fn bytes_format(bytes: &[u8], encoding: BytesEncoding) -> Term<'static> {
-    match encoding {
-        BytesEncoding::Base64 { .. } | BytesEncoding::Hex { .. } if bytes.is_empty() => {
-            Term(T::List(vec![]))
-        }
-        BytesEncoding::Base64 { split: false } => Term(T::OwnedStr(
-            base64::encode_config(bytes, base64::URL_SAFE_NO_PAD).into_bytes(),
-        )),
-        BytesEncoding::Base64 { split: true } => {
         let chunks = bytes
             .chunks(48)
-                .map(|b| {
+            .map(|b| T::OwnedStr(base64::encode_config(b, base64::URL_SAFE_NO_PAD).into_bytes()))
-                    T::OwnedStr(base64::encode_config(b, base64::URL_SAFE_NO_PAD).into_bytes())
-                })
             .collect::<Vec<_>>();
         if chunks.len() > 1 {
             Term(T::Seq(chunks))
@@ -142,18 +137,39 @@ pub fn bytes_format(bytes: &[u8], encoding: BytesEncoding) -> Term<'static> {
             Term(chunks.into_iter().next().unwrap())
         }
     }
-        BytesEncoding::Hex { split: false } => Term(T::OwnedStr(hex::encode(bytes).into_bytes())),
+}
-        BytesEncoding::Hex { split: true } => {
+
-            let chunks = bytes
+/// Term corresponding to a byte slice,
-                .chunks(32)
+/// encoding using base64 url-safe encoding without padding,
-                .map(|b| T::OwnedStr(hex::encode(b).into_bytes()))
+/// with a prefix used to identify its content type.
-                .collect::<Vec<_>>();
+/// The marker prefix is typically used in crypto settings to identify
-            if chunks.len() > 1 {
+/// a cryptographic protocol or algorithm; it may not contain the `:` character.
-                Term(T::Seq(chunks))
+///
+/// Example:
+///
+/// ```
+/// use nettext::enc::*;
+///
+/// assert_eq!(marked_bytes("mytype", b"").unwrap().encode(), b"mytype:-");
+/// assert_eq!(marked_bytes("mytype", b"hello, world!").unwrap().encode(), b"mytype:aGVsbG8sIHdvcmxkIQ");
+/// ```
+pub fn marked_bytes(marker: &str, bytes: &[u8]) -> Result<'static> {
+    for c in marker.as_bytes().iter() {
+        if !is_string_char(*c) || *c == b':' {
+            return Err(Error::InvalidCharacter(*c));
+        }
+    }
+    if bytes.is_empty() {
+        Ok(Term(T::OwnedStr(format!("{}:-", marker).into_bytes())))
     } else {
-                Term(chunks.into_iter().next().unwrap())
+        Ok(Term(T::OwnedStr(
-            }
+            format!(
-        }
+                "{}:{}",
+                marker,
+                base64::encode_config(bytes, base64::URL_SAFE_NO_PAD)
+            )
+            .into_bytes(),
+        )))
     }
 }
 

src/lib.rs

@@ -6,7 +6,7 @@
 //! use nettext::crypto::*;
 //!
 //! let final_payload = {
-//!     let keypair = SigningKeyPair::gen_with_defaults();
+//!     let keypair = gen_signing_keypair();
 //!
 //!     // Encode a fist object that represents a payload that will be hashed and signed
 //!     let signed_payload = seq([
@@ -18,12 +18,12 @@
 //!             ("c", raw(b"{ a = 12; b = 42 }").unwrap()),
 //!             ("d", bytes_split(&((0..128u8).collect::<Vec<_>>()))),
 //!         ]).unwrap(),
-//!         keypair.public_key.term().unwrap(),
+//!         keypair.public_key().term().unwrap(),
 //!     ]).unwrap().encode();
 //!     eprintln!("{}", std::str::from_utf8(&signed_payload).unwrap());
 //!
 //!     let hash = compute_hash(&signed_payload, None);
-//!     let sign = compute_signature(&signed_payload[..], &keypair.secret_key);
+//!     let sign = compute_signature(&signed_payload[..], &keypair);
 //!
 //!     // Encode a second object that represents the signed and hashed payload
 //!     dict([
@@ -62,13 +62,13 @@
 //!     d = AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIjJCUmJygpKissLS4v
 //!       MDEyMzQ1Njc4OTo7PD0-P0BBQkNERUZHSElKS0xNTk9QUVJTVFVWV1hZWltcXV5f
 //!       YGFiY2RlZmdoaWprbG1ub3BxcnN0dXZ3eHl6e3x9fn8;
-//!   } ZCkE-mTMlK3355u_0UzabRbSNcNO3CWAur7dAhglYtI
+//!   } pk.ed25519:inYgWFyL_BzZTsXNKp71r2aVct_3Izi_bkerbzOiz94
 //! ```
 //!
 //! And the value of `final_payload` would be as follows:
 //! ```raw
 //! {
-//!   hash = fTTk8Hm0HLGwaskCIqFBzRVMrVTeXGetmNBK2X3pNyY;
+//!   hash = h.b2:B1AnRocS90DmqxynGyvvBNuh-brucNO7-5hrsGplJr0;
 //!   payload = CALL myfunction {
 //!     a = hello;
 //!     b = world;
@@ -76,8 +76,8 @@
 //!     d = AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIjJCUmJygpKissLS4v
 //!       MDEyMzQ1Njc4OTo7PD0-P0BBQkNERUZHSElKS0xNTk9QUVJTVFVWV1hZWltcXV5f
 //!       YGFiY2RlZmdoaWprbG1ub3BxcnN0dXZ3eHl6e3x9fn8;
-//!   } ZCkE-mTMlK3355u_0UzabRbSNcNO3CWAur7dAhglYtI;
+//!   } pk.ed25519:inYgWFyL_BzZTsXNKp71r2aVct_3Izi_bkerbzOiz94;
-//!   signature = XPMrlhAIMfZb6a5Fh5F_ZaEf61olJ1hK4I2kh7vEPT1n20S-943X5cH35bb0Bfwkvy_ENfOTbb3ep1zn2lSIBg;
+//!   signature = sig.ed25519:LvLC1gHxNxUH44HHQRO-zWtLM4WyXhiYLFr94qTdI311Wa-kmgZsaWqSWe3jcjkS4PnsWSNt5apgbhR68cWWCg;
 //! }
 //! ```
 //!
@@ -93,30 +93,6 @@ pub mod crypto;
 #[cfg(feature = "serde")]
 pub mod serde;
 
-/// Possible encodings for byte strings in NetText
-#[derive(Clone, Copy)]
-pub enum BytesEncoding {
-    /// Base64 encoding (default)
-    Base64 { split: bool },
-    /// Hexadecimal encoding
-    Hex { split: bool },
-}
-
-impl Default for BytesEncoding {
-    fn default() -> Self {
-        BytesEncoding::Base64 { split: true }
-    }
-}
-
-impl BytesEncoding {
-    pub fn without_whitespace(&self) -> Self {
-        match self {
-            BytesEncoding::Base64 { .. } => BytesEncoding::Base64 { split: false },
-            BytesEncoding::Hex { .. } => BytesEncoding::Hex { split: false },
-        }
-    }
-}
-
 // ---- syntactic elements of the data format ----
 
 pub(crate) const DICT_OPEN: u8 = b'{';

src/serde/mod.rs

@@ -4,7 +4,6 @@ mod de;
 mod error;
 mod ser;
 
-pub use crate::BytesEncoding;
 pub use de::{from_bytes, from_term, Deserializer};
 pub use error::{Error, Result};
 pub use ser::{to_bytes, to_term, Serializer};

src/serde/ser.rs

@@ -2,15 +2,11 @@ use serde::{ser, Serialize};
 
 use crate::enc::*;
 use crate::serde::error::{Error, Result};
-use crate::BytesEncoding;
 use serde::ser::Error as SerError;
 
 /// Serde serializer for nettext
 #[derive(Clone, Copy, Default)]
-pub struct Serializer {
+pub struct Serializer;
-    pub string_format: BytesEncoding,
-    pub bytes_format: BytesEncoding,
-}
 
 /// Serialize value to nettext encoder term
 pub fn to_term<T>(value: &T) -> Result<Term<'static>>
@@ -94,11 +90,11 @@ impl<'a> ser::Serializer for &'a mut Serializer {
     }
 
     fn serialize_str(self, v: &str) -> Result<Self::Ok> {
-        Ok(bytes_format(v.as_bytes(), self.string_format))
+        Ok(bytes(v.as_bytes()))
     }
 
     fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok> {
-        Ok(bytes_format(v, self.bytes_format))
+        Ok(bytes(v))
     }
 
     fn serialize_none(self) -> Result<Self::Ok> {
@@ -313,10 +309,7 @@ impl ser::SerializeMap for MapSerializer {
     where
         T: ?Sized + Serialize,
     {
-        let mut ser = Serializer {
+        let mut ser = Serializer;
-            string_format: self.ser.string_format.without_whitespace(),
-            bytes_format: self.ser.bytes_format.without_whitespace(),
-        };
         self.next = Some(key.serialize(&mut ser)?.encode());
         Ok(())
     }