Reuse txn rlp (#547)

* Reuse RLP for txn signature checking * Apply comment * Change comments
0xPolygonZero · Aug 26, 2024 · 4ac1f5d · 4ac1f5d
1 parent 9529cf8
commit 4ac1f5d
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Showing 4 changed files with 71 additions and 283 deletions.
diff --git a/evm_arithmetization/src/cpu/kernel/asm/transactions/type_0.asm b/evm_arithmetization/src/cpu/kernel/asm/transactions/type_0.asm
@@ -18,131 +18,97 @@ global process_type_0_txn:
     %stack (rlp_addr, len) -> (rlp_addr)
 
     // stack: rlp_addr, retdest
+    // Keep track of the nonce position.
+    DUP1
+    // stack: rlp_addr, nonce_addr, retdest
     %decode_and_store_nonce
     %decode_and_store_gas_price_legacy
     %decode_and_store_gas_limit
     %decode_and_store_to
     %decode_and_store_value
     %decode_and_store_data
-    // stack: rlp_addr, retdest
+    // stack: rlp_addr, nonce_addr, retdest
+    DUP1
 
     // Parse the "v" field.
-    // stack: rlp_addr, retdest
+    // stack: rlp_addr, after_data_addr, nonce_addr, retdest
     %decode_rlp_scalar
-    // stack: rlp_addr, v, retdest
+    // stack: rlp_addr, v, after_data_addr, nonce_addr, retdest
     SWAP1
-    // stack: v, rlp_addr, retdest
+    // stack: v, rlp_addr, after_data_addr, nonce_addr, retdest
     DUP1
     %gt_const(28)
-    // stack: v > 28, v, rlp_addr, retdest
+    // stack: v > 28, v, rlp_addr, after_data_addr, nonce_addr, retdest
     %jumpi(process_v_new_style)
 
     // We have an old style v, so y_parity = v - 27.
     // No chain ID is present, so we can leave TXN_FIELD_CHAIN_ID_PRESENT and
     // TXN_FIELD_CHAIN_ID with their default values of zero.
-    // stack: v, rlp_addr, retdest
+    // stack: v, rlp_addr, after_data_addr, nonce_addr, retdest
     %sub_const(27)
-    %stack (y_parity, rlp_addr) -> (y_parity, rlp_addr)
     %mstore_txn_field(@TXN_FIELD_Y_PARITY)
 
-    // stack: rlp_addr, retdest
+    // stack: rlp_addr, after_data_addr, nonce_addr, retdest
     %jump(decode_r_and_s)
 
 process_v_new_style:
-    // stack: v, rlp_addr, retdest
+    // stack: v, rlp_addr, after_data_addr, nonce_addr, retdest
     // We have a new style v, so chain_id_present = 1,
     // chain_id = (v - 35) / 2, and y_parity = (v - 35) % 2.
     %stack (v, rlp_addr) -> (1, v, rlp_addr)
     %mstore_txn_field(@TXN_FIELD_CHAIN_ID_PRESENT)
 
-    // stack: v, rlp_addr, retdest
+    // stack: v, rlp_addr, after_data_addr, nonce_addr, retdest
     %sub_const(35)
     DUP1
-    // stack: v - 35, v - 35, rlp_addr, retdest
+    // stack: v - 35, v - 35, rlp_addr, after_data_addr, nonce_addr, retdest
     %div2
-    // stack: chain_id, v - 35, rlp_addr, retdest
+    // stack: chain_id, v - 35, rlp_addr, after_data_addr, nonce_addr, retdest
     %mstore_txn_field(@TXN_FIELD_CHAIN_ID)
 
-    // stack: v - 35, rlp_addr, retdest
+    // stack: v - 35, rlp_addr, after_data_addr, nonce_addr, retdest
     %mod_const(2)
-    // stack: y_parity, rlp_addr, retdest
+    // stack: y_parity, rlp_addr, after_data_addr, nonce_addr, retdest
     %mstore_txn_field(@TXN_FIELD_Y_PARITY)
 
 decode_r_and_s:
-    // stack: rlp_addr, retdest
+    // stack: rlp_addr, after_data_addr, nonce_addr, retdest
     %decode_and_store_r
     %decode_and_store_s
-    // stack: rlp_addr, retdest
+    // stack: rlp_addr, after_data_addr, nonce_addr, retdest
     POP
-    // stack: retdest
+    // stack: after_data_addr, nonce_addr, retdest
 
 type_0_compute_signed_data:
     // If a chain_id is present in v, the signed data is
     //     keccak256(rlp([nonce, gas_price, gas_limit, to, value, data, chain_id, 0, 0]))
     // otherwise, it is
     //     keccak256(rlp([nonce, gas_price, gas_limit, to, value, data]))
+    // We know that [nonce, gas_price, gas_limit, to, value, data] is already encoded
+    // at `nonce_addr`.
 
-    %alloc_rlp_block
-    // stack: rlp_addr_start, retdest
-    %mload_txn_field(@TXN_FIELD_NONCE)
-    // stack: nonce, rlp_addr_start, retdest
-    DUP2
-    // stack: rlp_addr, nonce, rlp_addr_start, retdest
-    %encode_rlp_scalar
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_MAX_FEE_PER_GAS)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_GAS_LIMIT)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_TO)
-    %mload_global_metadata(@GLOBAL_METADATA_CONTRACT_CREATION) %jumpi(zero_to)
-    // stack: to, rlp_addr, rlp_addr_start, retdest
-    SWAP1 %encode_rlp_160
-    %jump(after_to)
-zero_to:
-    // stack: to, rlp_addr, rlp_addr_start, retdest
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-after_to:
-    %mload_txn_field(@TXN_FIELD_VALUE)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    // Encode txn data.
-    %mload_txn_field(@TXN_FIELD_DATA_LEN)
-    PUSH @SEGMENT_TXN_DATA
-    // stack: ADDR, len, rlp_addr, rlp_addr_start, retdest
-    PUSH after_serializing_txn_data
-    // stack: after_serializing_txn_data, ADDR, len, rlp_addr, rlp_addr_start, retdest
-    SWAP3
-    // stack: rlp_addr, ADDR, len, after_serializing_txn_data, rlp_addr_start, retdest
-    %jump(encode_rlp_string)
-
-after_serializing_txn_data:
-    // stack: rlp_addr, rlp_addr_start, retdest
+    // If there is a `chain_id`, we append it at the end. This will overwrite `v`, `r` and `s`
+    // but the transaction has already been inserted in the MPT so it's not an issue.
+    // stack: after_data_addr, nonce_addr, retdest
     %mload_txn_field(@TXN_FIELD_CHAIN_ID_PRESENT)
     ISZERO %jumpi(finish_rlp_list)
-    // stack: rlp_addr, rlp_addr_start, retdest
-
+    // stack: after_data_addr, nonce_addr, retdest
     %mload_txn_field(@TXN_FIELD_CHAIN_ID)
     %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
+    // stack: rlp_signed_end_addr, nonce_addr, retdest
 
     PUSH 0
     %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
+    // stack: rlp_signed_end_addr, rlp_addr_start, retdest
 
     PUSH 0
     %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
+    // stack: rlp_signed_end_addr, rlp_addr_start, retdest
 
 finish_rlp_list:
+    // stack: rlp_signed_end_addr, rlp_addr_start, retdest
+    // We will overwrite the original transaction RLP prefix. This is fine since we don't need the
+    // original encoding anymore.
     %prepend_rlp_list_prefix
     // stack: ADDR, rlp_len, retdest
     KECCAK_GENERAL

diff --git a/evm_arithmetization/src/cpu/kernel/asm/transactions/type_1.asm b/evm_arithmetization/src/cpu/kernel/asm/transactions/type_1.asm
@@ -16,6 +16,10 @@ global process_type_1_txn:
     %stack (rlp_addr, len) -> (rlp_addr)
 
     %store_chain_id_present_true
+    // stack: rlp_addr, retdest
+    // Keep track of the chain id position.
+    DUP1
+    // stack: rlp_addr, chain_id_addr, retdest
     %decode_and_store_chain_id
     %decode_and_store_nonce
     %decode_and_store_gas_price_legacy
@@ -24,80 +28,25 @@ global process_type_1_txn:
     %decode_and_store_value
     %decode_and_store_data
     %decode_and_store_access_list
+    // stack: rlp_addr, chain_id_addr, retdest
+    DUP1
+    // stack: rlp_addr, after_access_list_addr, chain_id_addr, retdest
     %decode_and_store_y_parity
     %decode_and_store_r
     %decode_and_store_s
 
-    // stack: rlp_addr, retdest
+    // stack: rlp_addr, after_access_list_addr, chain_id_addr, retdest
     POP
-    // stack: retdest
+    // stack: after_access_list_addr, chain_id_addr, retdest
 
 // From EIP-2930:
 // The signatureYParity, signatureR, signatureS elements of this transaction represent a secp256k1 signature
 // over keccak256(0x01 || rlp([chainId, nonce, gasPrice, gasLimit, to, value, data, accessList])).
+// We know that [chainId, nonce, gasPrice, gasLimit, to, value, data, accessList] is already encoded
+// at `chain_id_addr`; we just need to overwrite the existing RLP prefix. This is fine since we don't
+// need the original encoding anymore.
 type_1_compute_signed_data:
-    %alloc_rlp_block
-    // stack: rlp_addr_start, retdest
-    %mload_txn_field(@TXN_FIELD_CHAIN_ID)
-    // stack: chain_id, rlp_addr_start, retdest
-    DUP2
-    // stack: rlp_addr, chain_id, rlp_addr_start, retdest
-    %encode_rlp_scalar
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_NONCE)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_MAX_FEE_PER_GAS)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_GAS_LIMIT)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_TO)
-    %mload_global_metadata(@GLOBAL_METADATA_CONTRACT_CREATION) %jumpi(zero_to)
-    // stack: to, rlp_addr, rlp_addr_start, retdest
-    SWAP1 %encode_rlp_160
-    %jump(after_to)
-zero_to:
-    // stack: to, rlp_addr, rlp_addr_start, retdest
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-after_to:
-    %mload_txn_field(@TXN_FIELD_VALUE)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_addr_start, retdest
-
-    // Encode txn data.
-    %mload_txn_field(@TXN_FIELD_DATA_LEN)
-    PUSH @SEGMENT_TXN_DATA // ctx == virt == 0
-    // stack: ADDR, len, rlp_addr, rlp_addr_start, retdest
-    PUSH after_serializing_txn_data
-    // stack: after_serializing_txn_data, ADDR, len, rlp_addr, rlp_addr_start, retdest
-    SWAP3
-    // stack: rlp_addr, ADDR, len, after_serializing_txn_data, rlp_addr_start, retdest
-    %jump(encode_rlp_string)
-
-after_serializing_txn_data:
-    // Instead of manually encoding the access list, we just copy the raw RLP from the transaction.
-    %mload_global_metadata(@GLOBAL_METADATA_ACCESS_LIST_RLP_START)
-    %mload_global_metadata(@GLOBAL_METADATA_ACCESS_LIST_RLP_LEN)
-    %stack (al_len, al_start, rlp_addr, rlp_addr_start, retdest) ->
-        (
-            rlp_addr,
-            al_start,
-            al_len,
-            after_serializing_access_list,
-            rlp_addr, rlp_addr_start, retdest)
-    %jump(memcpy_bytes)
-after_serializing_access_list:
-    // stack: rlp_addr, rlp_addr_start, retdest
-    %mload_global_metadata(@GLOBAL_METADATA_ACCESS_LIST_RLP_LEN) ADD
-    // stack: rlp_addr, rlp_addr_start, retdest
+    // stack: after_access_list_addr, chain_id_addr, retdest
     %prepend_rlp_list_prefix
     // stack: prefix_start_rlp_addr, rlp_len, retdest
 

diff --git a/evm_arithmetization/src/cpu/kernel/asm/transactions/type_2.asm b/evm_arithmetization/src/cpu/kernel/asm/transactions/type_2.asm
@@ -18,6 +18,10 @@ global process_type_2_txn:
 
     // stack: rlp_addr, retdest
     %store_chain_id_present_true
+    // stack: rlp_addr, retdest
+    // Keep track of the chain id position.
+    DUP1
+    // stack: rlp_addr, chain_id_addr, retdest
     %decode_and_store_chain_id
     %decode_and_store_nonce
     %decode_and_store_max_priority_fee
@@ -27,84 +31,25 @@ global process_type_2_txn:
     %decode_and_store_value
     %decode_and_store_data
     %decode_and_store_access_list
+    // stack: rlp_addr, chain_id_addr, retdest
+    DUP1
+    // stack: rlp_addr, after_access_list_addr, chain_id_addr, retdest
     %decode_and_store_y_parity
     %decode_and_store_r
     %decode_and_store_s
 
-    // stack: rlp_addr, retdest
+    // stack: rlp_addr, after_access_list_addr, chain_id_addr, retdest
     POP
-    // stack: retdest
+    // stack: after_access_list_addr, chain_id_addr, retdest
 
 // From EIP-1559:
 // The signature_y_parity, signature_r, signature_s elements of this transaction represent a secp256k1 signature over
-// keccak256(0x02 || rlp([chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, destination, amount, data, access_list]))
+// keccak256(0x02 || rlp([chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, destination, amount, data, access_list])).
+// We know that [chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, destination, amount, data, access_list] is already encoded
+// at `chain_id_addr`; we just need to overwrite the existing RLP prefix. This is fine since we don't
+// need the original encoding anymore.
 type_2_compute_signed_data:
-    %alloc_rlp_block
-    // stack: rlp_addr_start, retdest
-    %mload_txn_field(@TXN_FIELD_CHAIN_ID)
-    // stack: chain_id, rlp_start, retdest
-    DUP2
-    // stack: rlp_addr, chain_id, rlp_start, retdest
-    %encode_rlp_scalar
-    // stack: rlp_addr, rlp_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_NONCE)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_MAX_PRIORITY_FEE_PER_GAS)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_MAX_FEE_PER_GAS)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_GAS_LIMIT)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_start, retdest
-
-    %mload_txn_field(@TXN_FIELD_TO)
-    %mload_global_metadata(@GLOBAL_METADATA_CONTRACT_CREATION) %jumpi(zero_to)
-    // stack: to, rlp_addr, rlp_start, retdest
-    SWAP1 %encode_rlp_160
-    %jump(after_to)
-zero_to:
-    // stack: to, rlp_addr, rlp_start, retdest
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_start, retdest
-
-after_to:
-    %mload_txn_field(@TXN_FIELD_VALUE)
-    %encode_rlp_scalar_swapped_inputs
-    // stack: rlp_addr, rlp_start, retdest
-
-    // Encode txn data.
-    %mload_txn_field(@TXN_FIELD_DATA_LEN)
-    PUSH @SEGMENT_TXN_DATA // ctx == virt == 0
-    // stack: ADDR, len, rlp_addr, rlp_start, retdest
-    PUSH after_serializing_txn_data
-    // stack: after_serializing_txn_data, ADDR, len, rlp_addr, rlp_start, retdest
-    SWAP3
-    // stack: rlp_addr, ADDR, len, after_serializing_txn_data, rlp_start, retdest
-    %jump(encode_rlp_string)
-
-after_serializing_txn_data:
-    // Instead of manually encoding the access list, we just copy the raw RLP from the transaction.
-    %mload_global_metadata(@GLOBAL_METADATA_ACCESS_LIST_RLP_START)
-    %mload_global_metadata(@GLOBAL_METADATA_ACCESS_LIST_RLP_LEN)
-    %stack (al_len, al_start, rlp_addr, rlp_start, retdest) ->
-        (
-            rlp_addr,
-            al_start,
-            al_len,
-            after_serializing_access_list,
-            rlp_addr, rlp_start, retdest)
-    %jump(memcpy_bytes)
-after_serializing_access_list:
-    // stack: rlp_addr, rlp_start, retdest
-    %mload_global_metadata(@GLOBAL_METADATA_ACCESS_LIST_RLP_LEN) ADD
-    // stack: rlp_addr, rlp_start, retdest
+    // stack: after_access_list_addr, chain_id_addr, retdest
     %prepend_rlp_list_prefix
     // stack: prefix_start_pos, rlp_len, retdest