Merge pull request #3061 from poanetwork/vb-fix-contract-verification

Fix verification of contracts with error messages in require in parent contract

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 ### Fixes
 
+- [#3061](https://github.com/poanetwork/blockscout/pull/3061) - Fix verification of contracts with error messages in require in parent contract
+
 ### Chore
 
 

apps/explorer/lib/explorer/smart_contract/verifier.ex

@@ -59,12 +59,13 @@ defmodule Explorer.SmartContract.Verifier do
       address_hash,
       constructor_arguments,
       autodetect_contructor_arguments,
-      contract_source_code
+      contract_source_code,
+      name
     )
   end
 
-  defp compare_bytecodes({:error, :name}, _, _, _, _), do: {:error, :name}
+  defp compare_bytecodes({:error, :name}, _, _, _, _, _), do: {:error, :name}
-  defp compare_bytecodes({:error, _}, _, _, _, _), do: {:error, :compilation}
+  defp compare_bytecodes({:error, _}, _, _, _, _, _), do: {:error, :compilation}
 
   # credo:disable-for-next-line /Complexity/
   defp compare_bytecodes(
@@ -72,7 +73,8 @@ defmodule Explorer.SmartContract.Verifier do
          address_hash,
          arguments_data,
          autodetect_contructor_arguments,
-         contract_source_code
+         contract_source_code,
+         contract_name
        ) do
     generated_bytecode = extract_bytecode(bytecode)
 
@@ -89,7 +91,7 @@ defmodule Explorer.SmartContract.Verifier do
         {:error, :generated_bytecode}
 
       has_constructor_with_params?(abi) && autodetect_contructor_arguments ->
-        result = ConstructorArguments.find_constructor_arguments(address_hash, abi, contract_source_code)
+        result = ConstructorArguments.find_constructor_arguments(address_hash, abi, contract_source_code, contract_name)
 
         if result do
           {:ok, %{abi: abi, contructor_arguments: result}}
@@ -105,7 +107,8 @@ defmodule Explorer.SmartContract.Verifier do
             address_hash,
             blockchain_bytecode_without_whisper,
             arguments_data,
-            contract_source_code
+            contract_source_code,
+            contract_name
           ) ->
         {:error, :constructor_arguments}
 

apps/explorer/lib/explorer/smart_contract/verifier/constructor_arguments.ex

@@ -5,7 +5,7 @@ defmodule Explorer.SmartContract.Verifier.ConstructorArguments do
   alias ABI.{FunctionSelector, TypeDecoder}
   alias Explorer.Chain
 
-  def verify(address_hash, contract_code, arguments_data, contract_source_code) do
+  def verify(address_hash, contract_code, arguments_data, contract_source_code, contract_name) do
     arguments_data = arguments_data |> String.trim_trailing() |> String.trim_leading("0x")
 
     creation_code =
@@ -18,7 +18,7 @@ defmodule Explorer.SmartContract.Verifier.ConstructorArguments do
     if verify_older_version(creation_code, contract_code, check_func) do
       true
     else
-      extract_constructor_arguments(creation_code, check_func, contract_source_code)
+      extract_constructor_arguments(creation_code, check_func, contract_source_code, contract_name)
     end
   end
 
@@ -31,22 +31,22 @@ defmodule Explorer.SmartContract.Verifier.ConstructorArguments do
     |> check_func.()
   end
 
-  defp extract_constructor_arguments(code, check_func, contract_source_code) do
+  defp extract_constructor_arguments(code, check_func, contract_source_code, contract_name) do
     case code do
       # Solidity ~ 4.23 # https://solidity.readthedocs.io/en/v0.4.23/metadata.html
       "a165627a7a72305820" <> <<_::binary-size(64)>> <> "0029" <> constructor_arguments ->
-        extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code)
+        extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code, contract_name)
 
       # Solidity >= 0.5.10 https://solidity.readthedocs.io/en/v0.5.10/metadata.html
       "a265627a7a72305820" <>
           <<_::binary-size(64)>> <> "64736f6c6343" <> <<_::binary-size(6)>> <> "0032" <> constructor_arguments ->
-        extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code)
+        extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code, contract_name)
 
       # Solidity >= 0.5.11 https://github.com/ethereum/solidity/blob/develop/Changelog.md#0511-2019-08-12
       # Metadata: Update the swarm hash to the current specification, changes bzzr0 to bzzr1 and urls to use bzz-raw://
       "a265627a7a72315820" <>
           <<_::binary-size(64)>> <> "64736f6c6343" <> <<_::binary-size(6)>> <> "0032" <> constructor_arguments ->
-        extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code)
+        extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code, contract_name)
 
       # Solidity >= 0.6.0 https://github.com/ethereum/solidity/blob/develop/Changelog.md#060-2019-12-17
       # https://github.com/ethereum/solidity/blob/26b700771e9cc9c956f0503a05de69a1be427963/docs/metadata.rst#encoding-of-the-metadata-hash-in-the-bytecode
@@ -60,33 +60,40 @@ defmodule Explorer.SmartContract.Verifier.ConstructorArguments do
       # Fixing PR has been created https://github.com/ethereum/solidity/pull/8174
       "a264697066735822" <>
           <<_::binary-size(68)>> <> "64736f6c6343" <> <<_::binary-size(6)>> <> "0033" <> constructor_arguments ->
-        extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code)
+        extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code, contract_name)
 
       <<>> ->
         check_func.("")
 
       <<_::binary-size(2)>> <> rest ->
-        extract_constructor_arguments(rest, check_func, contract_source_code)
+        extract_constructor_arguments(rest, check_func, contract_source_code, contract_name)
     end
   end
 
-  defp extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code) do
+  defp extract_constructor_arguments_check_func(constructor_arguments, check_func, contract_source_code, contract_name) do
     constructor_arguments =
-      remove_require_messages_from_constructor_arguments(contract_source_code, constructor_arguments)
+      remove_require_messages_from_constructor_arguments(contract_source_code, constructor_arguments, contract_name)
 
     check_func_result = check_func.(constructor_arguments)
 
     if check_func_result do
       check_func_result
     else
-      extract_constructor_arguments(constructor_arguments, check_func, contract_source_code)
+      extract_constructor_arguments(constructor_arguments, check_func, contract_source_code, contract_name)
     end
   end
 
-  def remove_require_messages_from_constructor_arguments(contract_source_code, constructor_arguments) do
+  def remove_require_messages_from_constructor_arguments(contract_source_code, constructor_arguments, contract_name) do
-    msgs_list =
+    all_msgs =
       contract_source_code
-      |> extract_require_messages_from_constructor()
+      |> extract_require_messages_from_constructor(contract_name)
+
+    filtered_msgs =
+      all_msgs
+      |> Enum.filter(fn require_msg -> require_msg != nil end)
+
+    msgs_list =
+      filtered_msgs
       |> Enum.reverse()
 
     Enum.reduce(msgs_list, constructor_arguments, fn msg, pure_constructor_arguments ->
@@ -100,7 +107,7 @@ defmodule Explorer.SmartContract.Verifier.ConstructorArguments do
     end)
   end
 
-  def find_constructor_arguments(address_hash, abi, contract_source_code) do
+  def find_constructor_arguments(address_hash, abi, contract_source_code, contract_name) do
     creation_code =
       address_hash
       |> Chain.contract_creation_input_data()
@@ -123,17 +130,17 @@ defmodule Explorer.SmartContract.Verifier.ConstructorArguments do
       end
     end
 
-    extract_constructor_arguments(creation_code, check_func, contract_source_code)
+    extract_constructor_arguments(creation_code, check_func, contract_source_code, contract_name)
   end
 
-  def extract_require_messages_from_constructor(contract_source_code) do
+  def extract_require_messages_from_constructor(contract_source_code, _contract_name) do
-    constructor = find_constructor_content(contract_source_code)
+    # todo: _contract_name is for parsing of actually used constructor for concrete contract 
-    require_contents = find_require_in_constructor(constructor)
+    require_contents = find_all_requires(contract_source_code)
 
     messages_list =
       Enum.reduce(require_contents, [], fn require_content, msgs ->
         msg = get_require_message_hex(require_content)
-        if msg, do: [msg | msgs]
+        if msg, do: [msg | msgs], else: msgs
       end)
 
     if messages_list, do: messages_list, else: []
@@ -165,19 +172,35 @@ defmodule Explorer.SmartContract.Verifier.ConstructorArguments do
     end
   end
 
-  def get_require_message_hex(require_content) do
+  def find_all_requires(contract_source_code) do
-    case String.split(require_content, ",", parts: 2) do
+    if contract_source_code do
-      [_ | [msg]] ->
+      [_ | requires] = String.split(contract_source_code, "require")
-        msg
-        |> String.trim()
-        |> String.trim_leading("\"")
-        |> String.trim_trailing("\"")
-        |> String.trim_leading("'")
-        |> String.trim_trailing("'")
-        |> Base.encode16(case: :lower)
 
-      [_] ->
+      Enum.reduce(requires, [], fn right_from_require, requires_list ->
-        nil
+        [_ | [right_from_require_inside]] = String.split(right_from_require, "(", parts: 2)
+        [require_content | _] = String.split(right_from_require_inside, ");", parts: 2)
+        [require_content | requires_list]
+      end)
+    else
+      []
+    end
+  end
+
+  def get_require_message_hex(require_content) do
+    parts = String.split(require_content, ",")
+
+    if Enum.count(parts) > 1 do
+      [msg] = Enum.take(parts, -1)
+
+      msg
+      |> String.trim()
+      |> String.trim_leading("\"")
+      |> String.trim_trailing("\"")
+      |> String.trim_leading("'")
+      |> String.trim_trailing("'")
+      |> Base.encode16(case: :lower)
+    else
+      nil
     end
   end
 end