crypto: do not make inner hash public

This allows ToBase58Check to no longer return results, since we
know the hashes will _always_ be correctly constructed.

CHANGELOG.md

@@ -17,14 +17,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 parameterized by the lifetime of the input byte slice.
 - Altered hashes to implement `AsRef<[u8]>` instead of `AsRef<Vec<u8>>`.
 - Renamed `hash::Signature` to `hash::UnknownSignature`.
+- All hash structs no longer publicly expose the underlying `Hash`. Instead, use `Into<Vec<u8>>` and `AsRef<[u8]>`.
+- `ToBase58Check` no longer returns a `Result` type.
 
 ### Deprecated
 
 - Nothing.
 
 ### Removed
 
-- Nothing.
+- Removed `ToBase58CheckError`.
 
 ### Fixed
 

crypto/src/base58.rs

@@ -24,14 +24,6 @@ pub enum FromBase58CheckError {
     IncorrectBase58Prefix,
 }
 
-/// Possible errors for ToBase58Check
-#[derive(Debug, Error)]
-pub enum ToBase58CheckError {
-    /// Data is too long
-    #[error("data too long")]
-    DataTooLong,
-}
-
 /// Create double hash of given binary data
 fn double_sha256(data: &[u8]) -> [u8; 32] {
     let digest = sha256(data);
@@ -41,7 +33,7 @@ fn double_sha256(data: &[u8]) -> [u8; 32] {
 /// A trait for converting a value to base58 encoded string.
 pub trait ToBase58Check {
     /// Converts a value of `self` to a base58 value, returning the owned string.
-    fn to_base58check(&self) -> Result<String, ToBase58CheckError>;
+    fn to_base58check(&self) -> String;
 }
 
 /// A trait for converting base58check encoded values.
@@ -55,14 +47,14 @@ pub trait FromBase58Check {
 }
 
 impl ToBase58Check for [u8] {
-    fn to_base58check(&self) -> Result<String, ToBase58CheckError> {
+    fn to_base58check(&self) -> String {
         // 4 bytes checksum
         let mut payload = Vec::with_capacity(self.len() + 4);
         payload.extend(self);
         let checksum = double_sha256(self);
         payload.extend(&checksum[..4]);
 
-        Ok(bs58::encode(payload).into_string())
+        bs58::encode(payload).into_string()
     }
 }
 
@@ -99,7 +91,7 @@ mod tests {
 
     #[test]
     fn test_encode() -> Result<(), anyhow::Error> {
-        let decoded = hex::decode("8eceda2f")?.to_base58check().unwrap();
+        let decoded = hex::decode("8eceda2f")?.to_base58check();
         let expected = "QtRAcc9FSRg";
         assert_eq!(expected, &decoded);
 

crypto/src/hash.rs

@@ -84,7 +84,7 @@ pub enum FromBytesError {
 macro_rules! define_hash {
     ($name:ident) => {
         #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-        pub struct $name(pub Hash);
+        pub struct $name(pub(crate) Hash);
 
         impl $name {
             fn from_bytes(data: &[u8]) -> Result<Self, FromBytesError> {
@@ -472,12 +472,8 @@ impl HashType {
                 hash.extend(self.base58check_prefix());
             }
             hash.extend(data);
-            hash.to_base58check()
-                // currently the error is returned if the input lenght exceeds 128 bytes
-                // that is the limitation of base58 crate, and there are no hash types
-                // exceeding that limit.
-                // TODO: remove this when TE-373 is implemented
-                .map_err(|_| unreachable!("Hash size should not exceed allowed 128 bytes"))
+
+            Ok(hash.to_base58check())
         }
     }
 

crypto/src/signature.rs

@@ -11,8 +11,8 @@
 
 use crate::base58::FromBase58CheckError;
 use crate::hash::{
-    BlsSignature, Ed25519Signature, FromBytesError, HashTrait, HashType, P256Signature,
-    Secp256k1Signature, UnknownSignature,
+    BlsSignature, Ed25519Signature, FromBytesError, HashTrait, P256Signature, Secp256k1Signature,
+    UnknownSignature,
 };
 use serde::{Deserialize, Serialize};
 
@@ -57,23 +57,23 @@ impl Signature {
 impl AsRef<[u8]> for Signature {
     fn as_ref(&self) -> &[u8] {
         match self {
-            Self::Ed25519(s) => s.0.as_ref(),
-            Self::Secp256k1(s) => s.0.as_ref(),
-            Self::P256(s) => s.0.as_ref(),
-            Self::Bls(s) => s.0.as_ref(),
-            Self::Unknown(s) => s.0.as_ref(),
+            Self::Ed25519(s) => s.as_ref(),
+            Self::Secp256k1(s) => s.as_ref(),
+            Self::P256(s) => s.as_ref(),
+            Self::Bls(s) => s.as_ref(),
+            Self::Unknown(s) => s.as_ref(),
         }
     }
 }
 
 impl From<Signature> for Vec<u8> {
     fn from(s: Signature) -> Self {
         match s {
-            Signature::Ed25519(s) => s.0,
-            Signature::Secp256k1(s) => s.0,
-            Signature::P256(s) => s.0,
-            Signature::Bls(s) => s.0,
-            Signature::Unknown(s) => s.0,
+            Signature::Ed25519(s) => s.into(),
+            Signature::Secp256k1(s) => s.into(),
+            Signature::P256(s) => s.into(),
+            Signature::Bls(s) => s.into(),
+            Signature::Unknown(s) => s.into(),
         }
     }
 }
@@ -82,12 +82,10 @@ impl TryFrom<Vec<u8>> for Signature {
     type Error = FromBytesError;
 
     fn try_from(hash: Vec<u8>) -> Result<Self, Self::Error> {
-        if hash.len() == HashType::BlsSignature.size() {
-            Ok(Signature::Bls(BlsSignature(hash)))
-        } else if hash.len() == HashType::UnknownSignature.size() {
-            Ok(Signature::Unknown(UnknownSignature(hash)))
+        if hash.len() == BlsSignature::hash_size() {
+            Ok(Signature::Bls(BlsSignature::try_from(hash)?))
         } else {
-            Err(FromBytesError::InvalidSize)
+            Ok(Signature::Unknown(UnknownSignature::try_from(hash)?))
         }
     }
 }
@@ -96,12 +94,10 @@ impl TryFrom<&[u8]> for Signature {
     type Error = FromBytesError;
 
     fn try_from(hash: &[u8]) -> Result<Self, Self::Error> {
-        if hash.len() == HashType::BlsSignature.size() {
-            Ok(Signature::Bls(BlsSignature(hash.to_vec())))
-        } else if hash.len() == HashType::UnknownSignature.size() {
-            Ok(Signature::Unknown(UnknownSignature(hash.to_vec())))
+        if let Ok(s) = BlsSignature::try_from(hash) {
+            Ok(Signature::Bls(s))
         } else {
-            Err(FromBytesError::InvalidSize)
+            Ok(Signature::Unknown(UnknownSignature::try_from(hash)?))
         }
     }
 }