add validator ETH addresses (ERC20)

pyproject.toml

@@ -49,6 +49,7 @@ include = ["CHANGES.md", "docs/*", "docs/validators.1", "validators/py.typed"]
 
 [tool.poetry.dependencies]
 python = "^3.8"
+eth-hash = {extras = ["pycryptodome"], version = "^0.5.2"}
 
 [tool.poetry.group.docs]
 optional = true

tests/crypto_addresses/__init__.py

@@ -0,0 +1,4 @@
+"""Test crypto addresses."""
+# -*- coding: utf-8 -*-
+
+# isort: skip_file

tests/crypto_addresses/test_eth_address.py

@@ -0,0 +1,45 @@
+"""Test ETH address."""
+# -*- coding: utf-8 -*-
+
+# external
+import pytest
+
+# local
+from validators import eth_address, ValidationFailure
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        "0x8ba1f109551bd432803012645ac136ddd64dba72",
+        "0x9cc14ba4f9f68ca159ea4ebf2c292a808aaeb598",
+        "0x5AEDA56215b167893e80B4fE645BA6d5Bab767DE",
+        "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
+        "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
+        "0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984",
+        "0x1234567890123456789012345678901234567890",
+        "0x57Ab1ec28D129707052df4dF418D58a2D46d5f51",
+    ],
+)
+def test_returns_true_on_valid_eth_address(value: str):
+    """Test returns true on valid eth address."""
+    assert eth_address(value)
+
+
+@pytest.mark.parametrize(
+    "value",
+    [
+        "0x742d35Cc6634C0532925a3b844Bc454e4438f44g",
+        "0x742d35Cc6634C0532925a3b844Bc454e4438f44",
+        "0xAbcdefg1234567890Abcdefg1234567890Abcdefg",
+        "0x7c8EE9977c6f96b6b9774b3e8e4Cc9B93B12b2c72",
+        "0x80fBD7F8B3f81D0e1d6EACAb69AF104A6508AFB1",
+        "0x7c8EE9977c6f96b6b9774b3e8e4Cc9B93B12b2c7g",
+        "0x7c8EE9977c6f96b6b9774b3e8e4Cc9B93B12b2c",
+        "0x7Fb21a171205f3B8d8E4d88A2d2f8A56E45DdB5c",
+        "validators.eth",
+    ],
+)
+def test_returns_failed_validation_on_invalid_eth_address(value: str):
+    """Test returns failed validation on invalid eth address."""
+    assert isinstance(eth_address(value), ValidationFailure)

validators/__init__.py

@@ -24,12 +24,14 @@
 from .utils import validator, ValidationFailure
 from .uuid import uuid
 
+from .crypto_addresses import eth_address
 from .i18n import es_cif, es_doi, es_nie, es_nif, fi_business_id, fi_ssn
 
 __all__ = (
     "amex",
     "between",
     "btc_address",
+    "eth_address",
     "card_number",
     "diners",
     "discover",

validators/crypto_addresses/__init__.py

@@ -0,0 +1,9 @@
+"""Crypto addresses."""
+# -*- coding: utf-8 -*-
+
+# isort: skip_file
+
+# local
+from .eth_address import eth_address
+
+__all__ = ("eth_address",)

validators/crypto_addresses/eth_address.py

@@ -0,0 +1,58 @@
+"""ETH Address."""
+# -*- coding: utf-8 -*-
+
+# standard
+import re
+
+# external
+from eth_hash.auto import keccak
+
+# local
+from validators.utils import validator
+
+
+def _validate_eth_checksum_address(addr: str):
+    """Validate ETH type checksum address."""
+    addr = addr.replace("0x", "")
+    addr_hash = keccak.new(addr.lower().encode("ascii")).digest().hex()
+
+    if len(addr) != 40:
+        return False
+
+    for i in range(0, 40):
+        if (int(addr_hash[i], 16) > 7 and addr[i].upper() != addr[i]) or (
+            int(addr_hash[i], 16) <= 7 and addr[i].lower() != addr[i]
+        ):
+            return False
+    return True
+
+
+@validator
+def eth_address(value: str, /):
+    """Return whether or not given value is a valid ethereum address.
+
+    Full validation is implemented for ERC20 addresses.
+
+    Examples:
+        >>> eth_address('0x9cc14ba4f9f68ca159ea4ebf2c292a808aaeb598')
+        # Output: True
+        >>> eth_address('0x8Ba1f109551bD432803012645Ac136ddd64DBa72')
+        # Output: ValidationFailure(func=eth_address, args=...)
+
+    Args:
+        value:
+            Ethereum address string to validate.
+
+    Returns:
+        (Literal[True]):
+            If `value` is a valid ethereum address.
+        (ValidationFailure):
+            If `value` is an invalid ethereum address.
+
+    """
+    if not value:
+        return False
+
+    return re.compile(r"^0x[0-9a-f]{40}$|^0x[0-9A-F]{40}$").match(
+        value
+    ) or _validate_eth_checksum_address(value)