Reject trailing characters in hashes and encoded values

Author: xiehuanyi

src/validators/encoding.py

@@ -25,7 +25,7 @@ def base16(value: str, /):
         (Literal[True]): If `value` is a valid base16 encoding.
         (ValidationError): If `value` is an invalid base16 encoding.
     """
-    return re.match(r"^[0-9A-Fa-f]+$", value) if value else False
+    return re.fullmatch(r"^[0-9A-Fa-f]+$", value) if value else False
 
 
 @validator
@@ -46,7 +46,7 @@ def base32(value: str, /):
         (Literal[True]): If `value` is a valid base32 encoding.
         (ValidationError): If `value` is an invalid base32 encoding.
     """
-    return re.match(r"^[A-Z2-7]+=*$", value) if value else False
+    return re.fullmatch(r"^[A-Z2-7]+=*$", value) if value else False
 
 
 @validator
@@ -67,7 +67,7 @@ def base58(value: str, /):
         (Literal[True]): If `value` is a valid base58 encoding.
         (ValidationError): If `value` is an invalid base58 encoding.
     """
-    return re.match(r"^[1-9A-HJ-NP-Za-km-z]+$", value) if value else False
+    return re.fullmatch(r"^[1-9A-HJ-NP-Za-km-z]+$", value) if value else False
 
 
 @validator
@@ -89,7 +89,7 @@ def base64(value: str, /):
         (ValidationError): If `value` is an invalid base64 encoding.
     """
     return (
-        re.match(r"^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$", value)
+        re.fullmatch(r"^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$", value)
         if value
         else False
     )

src/validators/hashes.py

@@ -25,7 +25,7 @@ def md5(value: str, /):
         (Literal[True]): If `value` is a valid MD5 hash.
         (ValidationError): If `value` is an invalid MD5 hash.
     """
-    return re.match(r"^[0-9a-f]{32}$", value, re.IGNORECASE) if value else False
+    return re.fullmatch(r"^[0-9a-f]{32}$", value, re.IGNORECASE) if value else False
 
 
 @validator
@@ -46,7 +46,7 @@ def sha1(value: str, /):
         (Literal[True]): If `value` is a valid SHA1 hash.
         (ValidationError): If `value` is an invalid SHA1 hash.
     """
-    return re.match(r"^[0-9a-f]{40}$", value, re.IGNORECASE) if value else False
+    return re.fullmatch(r"^[0-9a-f]{40}$", value, re.IGNORECASE) if value else False
 
 
 @validator
@@ -67,7 +67,7 @@ def sha224(value: str, /):
         (Literal[True]): If `value` is a valid SHA224 hash.
         (ValidationError): If `value` is an invalid SHA224 hash.
     """
-    return re.match(r"^[0-9a-f]{56}$", value, re.IGNORECASE) if value else False
+    return re.fullmatch(r"^[0-9a-f]{56}$", value, re.IGNORECASE) if value else False
 
 
 @validator
@@ -91,7 +91,7 @@ def sha256(value: str, /):
         (Literal[True]): If `value` is a valid SHA256 hash.
         (ValidationError): If `value` is an invalid SHA256 hash.
     """
-    return re.match(r"^[0-9a-f]{64}$", value, re.IGNORECASE) if value else False
+    return re.fullmatch(r"^[0-9a-f]{64}$", value, re.IGNORECASE) if value else False
 
 
 @validator
@@ -115,7 +115,7 @@ def sha384(value: str, /):
         (Literal[True]): If `value` is a valid SHA384 hash.
         (ValidationError): If `value` is an invalid SHA384 hash.
     """
-    return re.match(r"^[0-9a-f]{96}$", value, re.IGNORECASE) if value else False
+    return re.fullmatch(r"^[0-9a-f]{96}$", value, re.IGNORECASE) if value else False
 
 
 @validator
@@ -140,4 +140,4 @@ def sha512(value: str, /):
         (Literal[True]): If `value` is a valid SHA512 hash.
         (ValidationError): If `value` is an invalid SHA512 hash.
     """
-    return re.match(r"^[0-9a-f]{128}$", value, re.IGNORECASE) if value else False
+    return re.fullmatch(r"^[0-9a-f]{128}$", value, re.IGNORECASE) if value else False

tests/test_encoding.py

@@ -1,5 +1,8 @@
 """Test Encodings."""
 
+# standard
+from typing import Callable
+
 # external
 import pytest
 
@@ -115,3 +118,15 @@ def test_returns_true_on_valid_base64(value: str):
 def test_returns_failed_validation_on_invalid_base64(value: str):
     """Test returns failed validation on invalid base64."""
     assert isinstance(base64(value), ValidationError)
+
+
+@pytest.mark.parametrize(
+    "validate, value",
+    [(base16, "a3f4b2"), (base32, "MFZWIZLTOQ======"), (base58, "18KToMF5"), (base64, "SGVsbG8=")],
+)
+@pytest.mark.parametrize("suffix", ["\n", "\r\n", " ", "\nextra"])
+def test_encoding_rejects_trailing_characters(
+    validate: Callable[[str], object], value: str, suffix: str
+):
+    """Reject characters outside the encoded value."""
+    assert isinstance(validate(value + suffix), ValidationError)

tests/test_hashes.py

@@ -1,5 +1,8 @@
 """Test Hashes."""
 
+# standard
+from typing import Callable
+
 # external
 import pytest
 
@@ -229,3 +232,15 @@ def test_returns_true_on_valid_sha512(value: str):
 def test_returns_failed_validation_on_invalid_sha512(value: str):
     """Test returns failed validation on invalid sha512."""
     assert isinstance(sha512(value), ValidationError)
+
+
+@pytest.mark.parametrize(
+    "validate, size",
+    [(md5, 32), (sha1, 40), (sha224, 56), (sha256, 64), (sha384, 96), (sha512, 128)],
+)
+@pytest.mark.parametrize("suffix", ["\n", "\r\n", " ", "\nextra"])
+def test_hash_rejects_trailing_characters(
+    validate: Callable[[str], object], size: int, suffix: str
+):
+    """Reject characters outside the fixed-length digest."""
+    assert isinstance(validate("a" * size + suffix), ValidationError)