Update EIP-7702: 7702 validity (#8845)

* 7702: adjust tx validity

* 7702: write checks in python instead

* typo

Co-authored-by: Mario Vega <[email protected]>

---------

Co-authored-by: Mario Vega <[email protected]>

EIPS/eip-7702.md

@@ -44,19 +44,22 @@ rlp([chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, dest
 authorization_list = [[chain_id, address, nonce, y_parity, r, s], ...]
 ```
 
-Transaction is considered invalid if authorization list items can't be decoded as:
-
-* `chain_id`: unsigned 256-bit integer.
-* `nonce`: unsigned 64-bit integer.
-* `address`: 20 bytes array.
-* `y_parity`: Value 0 or 1.
-* `r`: unsigned 256-bit integer.
-* `s`: unsigned 256-bit integer and value less or equal than `secp256k1n/2`, specified in [EIP-2](./eip-2.md).
-
 The fields `chain_id`, `nonce`, `max_priority_fee_per_gas`, `max_fee_per_gas`, `gas_limit`, `destination`, `value`, `data`, and `access_list` of the outer transaction follow the same semantics as [EIP-4844](./eip-4844.md). *Note, this means a null destination is not valid.*
 
 The `authorization_list` is a list of tuples that store the address to code which the signer desires to execute in the context of their EOA. The transaction is considered invalid if the length of `authorization_list` is zero.
 
+The transaction is also considered invalid when any field in an authorization
+tuple cannot fit within the following bounds:
+
+```python
+assert auth.chain_id < 2**256
+assert auth.nonce < 2**64
+assert len(auth.address) == 20
+assert auth.y_parity < 2**256
+assert auth.r < 2**256
+assert auth.s < 2**256
+```
+
 The [EIP-2718](./eip-2718.md) `ReceiptPayload` for this transaction is `rlp([status, cumulative_transaction_gas_used, logs_bloom, logs])`.
 
 #### Behavior