Add tx sechashes as entropy src for established acct addr gen

.changelog/unreleased/improvements/2781-addr-generator-randomness.md

@@ -0,0 +1,3 @@
+- Adds a transaction's code and data section hashes as additional
+  sources of entropy, to compute an established account's address.
+  ([\#2781](https://github.com/anoma/namada/pull/2781))

crates/core/src/address.rs

@@ -8,7 +8,6 @@ use std::hash::Hash;
 use std::str::FromStr;
 
 use borsh::{BorshDeserialize, BorshSchema, BorshSerialize};
-use borsh_ext::BorshSerializeExt;
 use data_encoding::HEXUPPER;
 use serde::{Deserialize, Serialize};
 use sha2::{Digest, Sha256};
@@ -460,14 +459,14 @@ impl EstablishedAddressGen {
         &mut self,
         rng_source: impl AsRef<[u8]>,
     ) -> Address {
-        let gen_bytes = self.serialize_to_vec();
-        let bytes = [&gen_bytes, rng_source.as_ref()].concat();
-        let full_hash = Sha256::digest(&bytes);
-        // take first 20 bytes of the hash
-        let mut hash: [u8; HASH_LEN] = Default::default();
-        hash.copy_from_slice(&full_hash[..HASH_LEN]);
-        self.last_hash = full_hash.into();
-        Address::Established(EstablishedAddress { hash })
+        self.last_hash = {
+            let mut hasher_state = Sha256::new();
+            hasher_state.update(self.last_hash);
+            hasher_state.update(rng_source);
+            hasher_state.finalize()
+        }
+        .into();
+        Address::Established(self.last_hash.into())
     }
 }
 
@@ -586,6 +585,7 @@ impl InternalAddress {
 
 #[cfg(test)]
 pub mod tests {
+    use borsh_ext::BorshSerializeExt;
     use proptest::prelude::*;
 
     use super::*;
@@ -652,17 +652,13 @@ pub fn gen_established_address(seed: impl AsRef<str>) -> Address {
     use rand::prelude::ThreadRng;
     use rand::{thread_rng, RngCore};
 
-    let mut key_gen = EstablishedAddressGen::new(seed);
+    EstablishedAddressGen::new(seed).generate_address({
+        let mut thread_local_rng: ThreadRng = thread_rng();
+        let mut buffer = [0u8; 32];
 
-    let mut rng: ThreadRng = thread_rng();
-    let mut rng_bytes = [0u8; 32];
-    rng.fill_bytes(&mut rng_bytes[..]);
-    let rng_source = rng_bytes
-        .iter()
-        .map(|b| format!("{:02X}", b))
-        .collect::<Vec<String>>()
-        .join("");
-    key_gen.generate_address(rng_source)
+        thread_local_rng.fill_bytes(&mut buffer[..]);
+        buffer
+    })
 }
 
 /// Generate a new established address. Unlike `gen_established_address`, this

crates/namada/src/vm/host_env.rs

@@ -1481,12 +1481,15 @@ where
 }
 
 /// Initialize a new account established address.
+#[allow(clippy::too_many_arguments)]
 pub fn tx_init_account<MEM, D, H, CA>(
     env: &TxVmEnv<MEM, D, H, CA>,
     code_hash_ptr: u64,
     code_hash_len: u64,
     code_tag_ptr: u64,
     code_tag_len: u64,
+    entropy_source_ptr: u64,
+    entropy_source_len: u64,
     result_ptr: u64,
 ) -> TxResult<()>
 where
@@ -1511,14 +1514,20 @@ where
 
     tx_validate_vp_code_hash::<MEM, D, H, CA>(env, &code_hash, &code_tag)?;
 
+    let (entropy_source, gas) = env
+        .memory
+        .read_bytes(entropy_source_ptr, entropy_source_len as _)
+        .map_err(|e| TxRuntimeError::MemoryError(Box::new(e)))?;
+    tx_charge_gas::<MEM, D, H, CA>(env, gas)?;
+
     tracing::debug!("tx_init_account");
 
     let code_hash = Hash::try_from(&code_hash[..])
         .map_err(|e| TxRuntimeError::InvalidVpCodeHash(e.to_string()))?;
     let mut state = env.state();
     let (write_log, in_mem, _db) = state.split_borrow();
     let gen = &in_mem.address_gen;
-    let (addr, gas) = write_log.init_account(gen, code_hash);
+    let (addr, gas) = write_log.init_account(gen, code_hash, &entropy_source);
     let addr_bytes = addr.serialize_to_vec();
     tx_charge_gas::<MEM, D, H, CA>(env, gas)?;
     let gas = env

crates/state/src/write_log.rs

@@ -353,13 +353,14 @@ impl WriteLog {
         &mut self,
         storage_address_gen: &EstablishedAddressGen,
         vp_code_hash: Hash,
+        entropy_source: &[u8],
     ) -> (Address, u64) {
         // If we've previously generated a new account, we use the local copy of
         // the generator. Otherwise, we create a new copy from the storage
-        let address_gen =
-            self.address_gen.get_or_insert(storage_address_gen.clone());
-        let addr =
-            address_gen.generate_address("TODO more randomness".as_bytes());
+        let address_gen = self
+            .address_gen
+            .get_or_insert_with(|| storage_address_gen.clone());
+        let addr = address_gen.generate_address(entropy_source);
         let key = storage::Key::validity_predicate(&addr);
         let gas = (key.len() + vp_code_hash.len()) as u64
             * STORAGE_WRITE_GAS_PER_BYTE;
@@ -743,7 +744,7 @@ mod tests {
         // init
         let init_vp = "initialized".as_bytes().to_vec();
         let vp_hash = Hash::sha256(init_vp);
-        let (addr, gas) = write_log.init_account(&address_gen, vp_hash);
+        let (addr, gas) = write_log.init_account(&address_gen, vp_hash, &[]);
         let vp_key = storage::Key::validity_predicate(&addr);
         assert_eq!(
             gas,
@@ -776,7 +777,7 @@ mod tests {
 
         let init_vp = "initialized".as_bytes().to_vec();
         let vp_hash = Hash::sha256(init_vp);
-        let (addr, _) = write_log.init_account(&address_gen, vp_hash);
+        let (addr, _) = write_log.init_account(&address_gen, vp_hash, &[]);
         let vp_key = storage::Key::validity_predicate(&addr);
 
         // update should fail
@@ -795,7 +796,7 @@ mod tests {
 
         let init_vp = "initialized".as_bytes().to_vec();
         let vp_hash = Hash::sha256(init_vp);
-        let (addr, _) = write_log.init_account(&address_gen, vp_hash);
+        let (addr, _) = write_log.init_account(&address_gen, vp_hash, &[]);
         let vp_key = storage::Key::validity_predicate(&addr);
 
         // delete should fail
@@ -830,7 +831,7 @@ mod tests {
 
         // initialize an account
         let vp1 = Hash::sha256("vp1".as_bytes());
-        let (addr1, _) = state.write_log.init_account(&address_gen, vp1);
+        let (addr1, _) = state.write_log.init_account(&address_gen, vp1, &[]);
         state.write_log.commit_tx();
 
         // write values

crates/tests/src/vm_host_env/ibc.rs

@@ -239,11 +239,15 @@ pub fn init_storage() -> (Address, Address) {
     });
 
     // initialize a token
-    let token = tx_host_env::ctx().init_account(code_hash, &None).unwrap();
+    let token = tx_host_env::ctx()
+        .init_account(code_hash, &None, &[])
+        .unwrap();
     let denom_key = token::storage_key::denom_key(&token);
     let token_denom = token::Denomination(ANY_DENOMINATION);
     // initialize an account
-    let account = tx_host_env::ctx().init_account(code_hash, &None).unwrap();
+    let account = tx_host_env::ctx()
+        .init_account(code_hash, &None, &[])
+        .unwrap();
     let key = token::storage_key::balance_key(&token, &account);
     let init_bal = Amount::from_uint(100, token_denom).unwrap();
     tx_host_env::with(|env| {

crates/tests/src/vm_host_env/mod.rs

@@ -214,7 +214,7 @@ mod tests {
         tx_host_env::init();
 
         let code = vec![];
-        tx::ctx().init_account(code, &None).unwrap();
+        tx::ctx().init_account(code, &None, &[]).unwrap();
     }
 
     #[test]
@@ -229,7 +229,7 @@ mod tests {
             let key = Key::wasm_code(&code_hash);
             env.state.write_bytes(&key, &code).unwrap();
         });
-        tx::ctx().init_account(code_hash, &None).unwrap();
+        tx::ctx().init_account(code_hash, &None, &[]).unwrap();
     }
 
     /// Test that a tx updating validity predicate that is not in the allowlist
@@ -329,7 +329,7 @@ mod tests {
         });
 
         // Initializing a new account with the VP should fail
-        tx::ctx().init_account(vp_hash, &None).unwrap();
+        tx::ctx().init_account(vp_hash, &None, &[]).unwrap();
     }
 
     #[test]

crates/tests/src/vm_host_env/tx.rs

@@ -485,6 +485,8 @@ mod native_tx_host_env {
         code_hash_len: u64,
         code_tag_ptr: u64,
         code_tag_len: u64,
+        entropy_source_ptr: u64,
+        entropy_source_len: u64,
         result_ptr: u64
     ));
     native_host_fn!(tx_emit_ibc_event(event_ptr: u64, event_len: u64));

crates/tx_env/src/lib.rs

@@ -38,6 +38,7 @@ pub trait TxEnv: StorageRead + StorageWrite {
         &mut self,
         code_hash: impl AsRef<[u8]>,
         code_tag: &Option<String>,
+        entropy_source: &[u8],
     ) -> Result<Address>;
 
     /// Update a validity predicate

crates/tx_prelude/src/lib.rs

@@ -290,6 +290,7 @@ impl TxEnv for Ctx {
         &mut self,
         code_hash: impl AsRef<[u8]>,
         code_tag: &Option<String>,
+        entropy_source: &[u8],
     ) -> Result<Address, Error> {
         let code_hash = code_hash.as_ref();
         let code_tag = code_tag.serialize_to_vec();
@@ -300,6 +301,8 @@ impl TxEnv for Ctx {
                 code_hash.len() as _,
                 code_tag.as_ptr() as _,
                 code_tag.len() as _,
+                entropy_source.as_ptr() as _,
+                entropy_source.len() as _,
                 result.as_ptr() as _,
             )
         };

crates/vm_env/src/lib.rs

@@ -76,6 +76,8 @@ pub mod tx {
             code_hash_len: u64,
             code_tag_ptr: u64,
             code_tag_len: u64,
+            entropy_source_ptr: u64,
+            entropy_source_len: u64,
             result_ptr: u64,
         );
 

wasm/wasm_source/src/tx_init_account.rs

@@ -3,6 +3,8 @@
 
 use namada_tx_prelude::*;
 
+const HASH_LEN: usize = hash::HASH_LENGTH;
+
 #[transaction(gas = 885069)]
 fn apply_tx(ctx: &mut Ctx, tx_data: Tx) -> TxResult {
     let signed = tx_data;
@@ -28,8 +30,20 @@ fn apply_tx(ctx: &mut Ctx, tx_data: Tx) -> TxResult {
             err
         })?;
 
+    let entropy = {
+        let mut buffer = [0u8; HASH_LEN * 2];
+
+        // Add code hash as entropy
+        buffer[..HASH_LEN].copy_from_slice(&signed.code_sechash().0);
+
+        // Add data hash as entropy
+        buffer[HASH_LEN..].copy_from_slice(&signed.data_sechash().0);
+
+        buffer
+    };
+
     let address =
-        ctx.init_account(vp_code_sec.code.hash(), &vp_code_sec.tag)?;
+        ctx.init_account(vp_code_sec.code.hash(), &vp_code_sec.tag, &entropy)?;
 
     match account::init_account(ctx, &address, tx_data) {
         Ok(address) => {