From d4391d883a552cb8db59f78a65f295b0ee753fd3 Mon Sep 17 00:00:00 2001
From: Jan Hnatek <jan.hnatek@showmax.com>
Date: Thu, 5 Sep 2024 11:47:10 +0200
Subject: [PATCH] fix(core): add EIP-712 nested arrays support (#2963)

---
 .../fixtures/ethereum/sign_typed_data.json    | 80 +++++++++++++++++++
 core/.changelog.d/2963.fixed                  |  1 +
 core/src/apps/ethereum/sign_typed_data.py     | 12 ++-
 python/src/trezorlib/ethereum.py              |  3 -
 4 files changed, 92 insertions(+), 4 deletions(-)
 create mode 100644 core/.changelog.d/2963.fixed

diff --git a/common/tests/fixtures/ethereum/sign_typed_data.json b/common/tests/fixtures/ethereum/sign_typed_data.json
index 35b484a160..7ac80d9222 100644
--- a/common/tests/fixtures/ethereum/sign_typed_data.json
+++ b/common/tests/fixtures/ethereum/sign_typed_data.json
@@ -757,6 +757,86 @@
                 "address": "0x73d0385F4d8E00C5e6504C6030F47BF6212736A8",
                 "sig": "0x4873bf73cf22e35776d8b23a249f93f38a6d5aa8c1a121281675094f5fac64b55a3b6cf28e140930f9185156d07f171a17e06925b5cebd95a2a8761d074e43f91c"
             }
+        },
+        {
+            "name": "nested_array_of_string",
+            "comment": "Nested arrays (issue #2963)",
+            "parameters": {
+                "path": "m/44'/60'/0'/0/0",
+                "metamask_v4_compat": true,
+                "data": {
+                    "types": {
+                        "EIP712Domain": [],
+                        "Message": [
+                            {
+                                "name": "text",
+                                "type": "string[][]"
+                            }
+                        ]
+                    },
+                    "primaryType": "Message",
+                    "message": {
+                        "text": [
+                            ["1", "2"],
+                            ["3", "4"]
+                        ]
+                    },
+                    "domain": {}
+                },
+                "message_hash": "0xc40dc798242ec8a6a0f2974e8f687583c118a6b74f161dc39cd79025d228ca1d",
+                "domain_separator_hash": null
+            },
+            "result": {
+                "address": "0x73d0385F4d8E00C5e6504C6030F47BF6212736A8",
+                "sig": "0x26df1807221e9a0ce4d3f0a6422c55f9cca7de55268a9d6c4772fd28893730b8755f3d23cef14ea02ea74c9045a3a8ae6a3f1ceb252cd2a6f3a43832d8a0c7b01c"
+            }
+        },
+        {
+            "name": "nested_array_of_object",
+            "comment": "Nested arrays (issue #2963)",
+            "parameters": {
+                "path": "m/44'/60'/0'/0/0",
+                "metamask_v4_compat": true,
+                "data": {
+                    "types": {
+                        "EIP712Domain": [],
+                        "Message": [
+                            {
+                                "name": "element",
+                                "type": "Element[][]"
+                            }
+                        ],
+                        "Element": [
+                            {
+                                "name": "foo",
+                                "type": "int8"
+                            }
+                        ]
+                    },
+                    "primaryType": "Message",
+                    "message": {
+                        "element": [
+                            [
+                                {
+                                    "foo": 1
+                                }
+                            ],
+                            [
+                                {
+                                    "foo": 2
+                                }
+                            ]
+                        ]
+                    },
+                    "domain": {}
+                },
+                "message_hash": "0x56034f4b5afe2fb032f1e60b3bc649c8725396d1e9b4d85725bdff1d366a86e6",
+                "domain_separator_hash": null
+            },
+            "result": {
+                "address": "0x73d0385F4d8E00C5e6504C6030F47BF6212736A8",
+                "sig": "0x6f2c2e2392ca20374679b4d34a2e910cf2357c32ce06c25592c1ebe5a77e76433e4b38d853ccce71930df085861a90c36611a24ba673964bf6a889a063c568311b"
+            }
         }
     ]
 }
diff --git a/core/.changelog.d/2963.fixed b/core/.changelog.d/2963.fixed
new file mode 100644
index 0000000000..2d2a691f97
--- /dev/null
+++ b/core/.changelog.d/2963.fixed
@@ -0,0 +1 @@
+Fixed EIP-712 nested arrays support.
diff --git a/core/src/apps/ethereum/sign_typed_data.py b/core/src/apps/ethereum/sign_typed_data.py
index 4fc2f0c095..848466f92d 100644
--- a/core/src/apps/ethereum/sign_typed_data.py
+++ b/core/src/apps/ethereum/sign_typed_data.py
@@ -374,7 +374,6 @@ class TypedDataEnvelope:
         for i in range(array_size):
             field_member_path[-1] = i
 
-            # TODO: we do not support arrays of arrays, check if we should
             if entry_type.data_type == EthereumDataType.STRUCT:
                 assert entry_type.struct_name is not None  # validate_field_type
 
@@ -387,6 +386,17 @@ class TypedDataEnvelope:
                     is_array_member=True,
                 )
 
+            elif entry_type.data_type == EthereumDataType.ARRAY:
+                await self.encode_array(
+                    arr_w,
+                    array_name,
+                    entry_type,
+                    field_member_path,
+                    show_array,
+                    parent_objects,
+                    current_parent_objects,
+                )
+
             else:
                 await self.encode_nonref(
                     arr_w,
diff --git a/python/src/trezorlib/ethereum.py b/python/src/trezorlib/ethereum.py
index 1cf2eeeaed..1be8983228 100644
--- a/python/src/trezorlib/ethereum.py
+++ b/python/src/trezorlib/ethereum.py
@@ -87,9 +87,6 @@ def get_field_type(type_name: str, types: dict) -> messages.EthereumFieldType:
         size = parse_array_n(type_name)
         member_typename = typeof_array(type_name)
         entry_type = get_field_type(member_typename, types)
-        # Not supporting nested arrays currently
-        if entry_type.data_type == messages.EthereumDataType.ARRAY:
-            raise NotImplementedError("Nested arrays are not supported")
     elif type_name.startswith("uint"):
         data_type = messages.EthereumDataType.UINT
         size = get_byte_size_for_int_type(type_name)