Add secp256k1_verify to Api

Implement secp256k1_verify for MockApi

packages/vm/src/backend.rs

@@ -127,6 +127,13 @@ pub trait Storage {
 pub trait Api: Copy + Clone + Send {
     fn canonical_address(&self, human: &HumanAddr) -> BackendResult<CanonicalAddr>;
     fn human_address(&self, canonical: &CanonicalAddr) -> BackendResult<HumanAddr>;
+
+    fn secp256k1_verify(
+        &self,
+        message_hash: &[u8],
+        signature: &[u8],
+        public_key: &[u8],
+    ) -> BackendResult<()>;
 }
 
 pub trait Querier {
@@ -168,6 +175,8 @@ pub enum BackendError {
     // This is the only error case of BackendError that is reported back to the contract.
     #[error("User error during call into backend: {msg}")]
     UserErr { msg: String },
+    #[error("Crypto error: {msg}")]
+    CryptoErr { msg: String },
 }
 
 impl BackendError {
@@ -203,6 +212,12 @@ impl BackendError {
             msg: msg.to_string(),
         }
     }
+
+    pub fn crypto_err<S: ToString>(msg: S) -> Self {
+        BackendError::CryptoErr {
+            msg: msg.to_string(),
+        }
+    }
 }
 
 impl From<FromUtf8Error> for BackendError {

packages/vm/src/testing/mock.rs

@@ -3,11 +3,13 @@ use cosmwasm_std::{BlockInfo, CanonicalAddr, Coin, ContractInfo, Env, HumanAddr,
 
 use super::querier::MockQuerier;
 use super::storage::MockStorage;
+use crate::crypto;
 use crate::{Api, Backend, BackendError, BackendResult, GasInfo};
 
 pub const MOCK_CONTRACT_ADDR: &str = "cosmos2contract";
 const GAS_COST_HUMANIZE: u64 = 44;
 const GAS_COST_CANONICALIZE: u64 = 55;
+const GAS_COST_VERIFY_SIGNATURE: u64 = 100;
 
 /// All external requirements that can be injected for unit tests.
 /// It sets the given balance for the contract itself, nothing else
@@ -134,6 +136,25 @@ impl Api for MockApi {
         };
         (result, gas_info)
     }
+
+    fn secp256k1_verify(
+        &self,
+        message_hash: &[u8],
+        signature: &[u8],
+        public_key: &[u8],
+    ) -> BackendResult<()> {
+        let gas_info = GasInfo::with_cost(GAS_COST_VERIFY_SIGNATURE);
+
+        if let Some(backend_error) = self.backend_error {
+            return (Err(BackendError::unknown(backend_error)), gas_info);
+        }
+
+        let result = match crypto::secp256k1_verify(message_hash, signature, public_key) {
+            Ok(_) => Ok(()),
+            Err(err) => Err(BackendError::crypto_err(err.to_string())),
+        };
+        (result, gas_info)
+    }
 }
 
 /// Returns a default enviroment with height, time, chain_id, and contract address