Implement ecdsa_to_eth_address() and remove eth_compatibility cra…

…te (#1233)

* ink_eth_compatibility::to_eth_address() removed, as well as libsecp256k1 dep

* added edcsa_to_eth_address() (except offchain env)

* added off-chain impl

* removed eth_compatibility crate

* removed dep on eth_compatibility

* fix: clean dependency on a struct from removed crate

* Apply suggestions from code review

Co-authored-by: Michael Müller <mich@elmueller.net>

* save

* bugfix for old offchain env impl of to_eth_address

* + doc comments

* ecdsa_to_default_account_id func ported from ink_eth_compatibility crate

* revert examples

* fix

* another fix

* more fix

* Apply suggestions from code review

Co-authored-by: Michael Müller <mich@elmueller.net>

* Revert "ecdsa_to_default_account_id func ported from ink_eth_compatibility crate"

This reverts commit 70a9189.

* missed clean up

Co-authored-by: Michael Müller <mich@elmueller.net>

Cargo.toml

@@ -12,7 +12,6 @@ members = [
     "crates/primitives",
     "crates/engine",
     "crates/env",
-    "crates/eth_compatibility",
     "crates/storage",
     "crates/storage/derive",
 ]

crates/env/src/api.rs

@@ -511,6 +511,34 @@ pub fn ecdsa_recover(
     })
 }
 
+/// Returns an Ethereum address from the ECDSA compressed public key.
+///
+/// # Example
+///
+/// ```
+/// let pub_key = [
+///     2, 141, 181, 91, 5, 219, 134, 192, 177, 120, 108, 164, 159, 9, 93, 118,
+///     52, 76, 158, 96, 86, 178, 240, 39, 1, 167, 231, 243, 194, 10, 171, 253,
+///     145,
+/// ];
+///  let EXPECTED_ETH_ADDRESS = [
+///     9, 35, 29, 167, 177, 154, 1, 111, 158, 87, 109, 35, 177, 98, 119, 6, 47,
+///     77, 70, 168,
+/// ];
+/// let mut output = [0; 20];
+/// ink_env::ecdsa_to_eth_address(&pub_key, &mut output);
+/// assert_eq!(output, EXPECTED_ETH_ADDRESS);
+/// ```
+///
+/// # Errors
+///
+/// - If the ECDSA public key cannot be recovered from the provided public key.
+pub fn ecdsa_to_eth_address(pubkey: &[u8; 33], output: &mut [u8; 20]) -> Result<()> {
+    <EnvInstance as OnInstance>::on_instance(|instance| {
+        instance.ecdsa_to_eth_address(pubkey, output)
+    })
+}
+
 /// Checks whether the specified account is a contract.
 ///
 /// # Errors

crates/env/src/backend.rs

@@ -253,6 +253,14 @@ pub trait EnvBackend {
         output: &mut [u8; 33],
     ) -> Result<()>;
 
+    /// Retrieves an Ethereum address from the ECDSA compressed `pubkey`
+    /// and stores the result in `output`.
+    fn ecdsa_to_eth_address(
+        &mut self,
+        pubkey: &[u8; 33],
+        output: &mut [u8; 20],
+    ) -> Result<()>;
+
     /// Low-level interface to call a chain extension method.
     ///
     /// Returns the output of the chain extension of the specified type.

crates/env/src/engine/off_chain/impls.rs

@@ -293,6 +293,20 @@ impl EnvBackend for EnvInstance {
         }
     }
 
+    fn ecdsa_to_eth_address(
+        &mut self,
+        pubkey: &[u8; 33],
+        output: &mut [u8; 20],
+    ) -> Result<()> {
+        let pk = secp256k1::PublicKey::from_slice(pubkey)
+            .map_err(|_| Error::EcdsaRecoveryFailed)?;
+        let uncompressed = pk.serialize_uncompressed();
+        let mut hash = <Keccak256 as HashOutput>::Type::default();
+        <Keccak256>::hash(&uncompressed[1..], &mut hash);
+        output.as_mut().copy_from_slice(&hash[12..]);
+        Ok(())
+    }
+
     fn call_chain_extension<I, T, E, ErrorCode, F, D>(
         &mut self,
         func_id: u32,

crates/env/src/engine/on_chain/ext.rs

@@ -378,6 +378,11 @@ mod sys {
             message_hash_ptr: Ptr32<[u8]>,
             output_ptr: Ptr32Mut<[u8]>,
         ) -> ReturnCode;
+
+        pub fn seal_ecdsa_to_eth_address(
+            public_key_ptr: Ptr32<[u8]>,
+            output_ptr: Ptr32Mut<[u8]>,
+        ) -> ReturnCode;
     }
 }
 
@@ -704,6 +709,16 @@ pub fn ecdsa_recover(
     ret_code.into()
 }
 
+pub fn ecdsa_to_eth_address(pubkey: &[u8; 33], output: &mut [u8; 20]) -> Result {
+    let ret_code = unsafe {
+        sys::seal_ecdsa_to_eth_address(
+            Ptr32::from_slice(pubkey),
+            Ptr32Mut::from_slice(output),
+        )
+    };
+    ret_code.into()
+}
+
 pub fn is_contract(account_id: &[u8]) -> bool {
     let ret_val = unsafe { sys::seal_is_contract(Ptr32::from_slice(account_id)) };
     ret_val.into_bool()

crates/env/src/engine/on_chain/impls.rs

@@ -295,6 +295,14 @@ impl EnvBackend for EnvInstance {
         ext::ecdsa_recover(signature, message_hash, output).map_err(Into::into)
     }
 
+    fn ecdsa_to_eth_address(
+        &mut self,
+        pubkey: &[u8; 33],
+        output: &mut [u8; 20],
+    ) -> Result<()> {
+        ext::ecdsa_to_eth_address(pubkey, output).map_err(Into::into)
+    }
+
     fn call_chain_extension<I, T, E, ErrorCode, F, D>(
         &mut self,
         func_id: u32,

crates/lang/Cargo.toml

@@ -20,7 +20,6 @@ ink_storage = { version = "3.0.1", path = "../storage", default-features = false
 ink_primitives = { version = "3.0.1", path = "../primitives", default-features = false }
 ink_metadata = { version = "3.0.1", path = "../metadata", default-features = false, optional = true }
 ink_prelude = { version = "3.0.1", path = "../prelude", default-features = false }
-ink_eth_compatibility = { version = "3.0.1", path = "../eth_compatibility", default-features = false }
 ink_lang_macro = { version = "3.0.1", path = "macro", default-features = false }
 
 scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive", "full"] }

crates/lang/src/env_access.rs

@@ -29,7 +29,6 @@ use ink_env::{
     Error,
     Result,
 };
-use ink_eth_compatibility::ECDSAPublicKey;
 
 /// The API behind the `self.env()` and `Self::env()` syntax in ink!.
 ///
@@ -831,10 +830,59 @@ where
         self,
         signature: &[u8; 65],
         message_hash: &[u8; 32],
-    ) -> Result<ECDSAPublicKey> {
+    ) -> Result<[u8; 33]> {
         let mut output = [0; 33];
         ink_env::ecdsa_recover(signature, message_hash, &mut output)
-            .map(|_| output.into())
+            .map(|_| output)
+            .map_err(|_| Error::EcdsaRecoveryFailed)
+    }
+
+    /// Returns an Ethereum address from the ECDSA compressed public key.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use ink_lang as ink;
+    /// # #[ink::contract]
+    /// # pub mod my_contract {
+    /// #     #[ink(storage)]
+    /// #     pub struct MyContract { }
+    /// #
+    /// #     impl MyContract {
+    /// #         #[ink(constructor)]
+    /// #         pub fn new() -> Self {
+    /// #             Self {}
+    /// #         }
+    /// #
+    /// #[ink(message)]
+    /// pub fn ecdsa_to_eth_address(&self) {
+    ///     let pub_key = [
+    ///         2, 141, 181, 91, 5, 219, 134, 192, 177, 120, 108, 164, 159, 9, 93, 118,
+    ///         52, 76, 158, 96, 86, 178, 240, 39, 1, 167, 231, 243, 194, 10, 171, 253,
+    ///         145,
+    ///     ];
+    ///      let EXPECTED_ETH_ADDRESS = [
+    ///         9, 35, 29, 167, 177, 154, 1, 111, 158, 87, 109, 35, 177, 98, 119, 6, 47,
+    ///         77, 70, 168,
+    ///     ];
+    ///     let output = self
+    ///         .env()
+    ///         .ecdsa_to_eth_address(&pub_key)
+    ///         .expect("must return an Ethereum address for the compressed public key");
+    ///     assert_eq!(output, EXPECTED_ETH_ADDRESS);
+    /// }
+    /// #
+    /// #     }
+    /// # }
+    /// ```
+    ///
+    /// # Note
+    ///
+    /// For more details visit: [`ink_env::ecdsa_to_eth_address`]
+    pub fn ecdsa_to_eth_address(self, pubkey: &[u8; 33]) -> Result<[u8; 20]> {
+        let mut output = [0; 20];
+        ink_env::ecdsa_to_eth_address(pubkey, &mut output)
+            .map(|_| output)
             .map_err(|_| Error::EcdsaRecoveryFailed)
     }