Support sha256 ABI

Cargo.toml

@@ -21,6 +21,7 @@ rand = "0.8"
 displaydoc = "0.2"
 thiserror = "1.0"
 chrono = { version = "0.4", features = ["clock"], default-features = false }
+sha2 = "0.10.6"
 # for gas_calibration middleware
 regex = "1"
 more-asserts = "0.3"

src/as_execution/abi.rs

@@ -1078,6 +1078,21 @@ where
     Ok(buffer)
 }
 
+/// performs a sha256 hash on byte array and returns the hash as byte array
+#[named]
+pub(crate) fn assembly_script_hash_sha256(
+    mut ctx: FunctionEnvMut<ASEnv>,
+    bytes: i32,
+) -> ABIResult<i32> {
+    let env = ctx.data().clone();
+    sub_remaining_gas_abi(&env, &mut ctx, function_name!())?;
+    let memory = get_memory!(env);
+    let bytes = read_buffer(memory, &ctx, bytes)?;
+    let hash = env.get_interface().hash_sha256(&bytes)?.to_vec();
+    let ptr = pointer_from_bytearray(&env, &mut ctx, &hash)?.offset();
+    Ok(ptr as i32)
+}
+
 #[cfg(test)]
 mod tests {
     use crate::as_execution::abi::ser_bytearray_vec;

src/as_execution/context.rs

@@ -257,6 +257,7 @@ impl ASContext {
                 "assembly_script_local_execution" => Function::new_typed_with_env(store, &fenv, assembly_script_local_execution),
                 "assembly_script_caller_has_write_access" => Function::new_typed_with_env(store, &fenv, assembly_script_caller_has_write_access),
                 "assembly_script_function_exists" => Function::new_typed_with_env(store, &fenv, assembly_script_function_exists),
+                "assembly_script_hash_sha256" =>  Function::new_typed_with_env(store, &fenv, assembly_script_hash_sha256),
             },
         };
 

src/tests/mod.rs

@@ -4,7 +4,7 @@ use crate::{GasCosts, RuntimeModule};
 
 use anyhow::{bail, Result};
 use parking_lot::Mutex;
-
+use sha2::{Digest, Sha256};
 use std::sync::Arc;
 use std::{collections::BTreeMap, str::FromStr};
 
@@ -230,6 +230,14 @@ impl Interface for TestInterface {
             .try_into()
             .unwrap())
     }
+
+    // Sha256 hash data
+    fn hash_sha256(&self, bytes: &[u8]) -> Result<[u8; 32]> {
+        let mut hasher = Sha256::new();
+        hasher.update(bytes);
+        let hash = hasher.finalize().into();
+        Ok(hash)
+    }
 }
 
 #[cfg(feature = "gas_calibration")]

src/types.rs

@@ -118,6 +118,7 @@ impl Default for GasCosts {
         abi_costs.insert(String::from("assembly_script_date_now"), 11);
         abi_costs.insert(String::from("assembly_script_console_log"), 36); // same cost as for generate_event
         abi_costs.insert(String::from("assembly_script_trace"), 36);
+        abi_costs.insert(String::from("assembly_script_hash_sha256"), 83);
         Self {
             operator_cost: 1,
             launch_cost: 10000,
@@ -381,6 +382,11 @@ pub trait Interface: Send + Sync + InterfaceClone {
     ) -> Result<()> {
         unimplemented!("send_message")
     }
+
+    // Sha256 hash bytes
+    fn hash_sha256(&self, bytes: &[u8]) -> Result<[u8; 32]> {
+        unimplemented!("hash_sha256")
+    }
 }
 
 impl dyn Interface {