Add function to automaticaly validate checksum string

Author: ddalu5

pyntegrity/config.py

@@ -20,8 +20,8 @@
 SHA256_LENGTH = 64
 MD5_LENGTH = 32
 
-SHA256_REX = rf"^[A-Fa-f0-9]{SHA256_LENGTH}$"
-MD5_REX = rf"^[a-fA-F\d]{MD5_LENGTH}$"
+SHA256_REX = r"^[A-Fa-f\d]{64}$"
+MD5_REX = r"^[a-fA-F\d]{32}$"
 
 SUPPORTED_HASH_ALGOS = {
     "sha256": {"REX": SHA256_REX, "LENGTH": SHA256_LENGTH},

pyntegrity/core.py

@@ -15,6 +15,8 @@
 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <https://www.gnu.org/licenses/>.
 """
+import re
+
 from .exceptions import HashStrNotValidException
 from .exceptions import HashAlgorithmNotSupportedException
 
@@ -38,3 +40,19 @@ def detect_hash_algo(hash_str: str):
         raise HashAlgorithmNotSupportedException(
             detected_length=hash_len, hash_str=hash_str
         )
+
+
+def validate_hash_str(hash_str: str):
+    """
+    Checks if the str is a valid checksum in the detected algorithm
+
+    :param hash_str:the hash string
+    :return: True if valid
+    :raises HashStrNotValidException: raised if the hash str isn't valid
+    """
+    hash_name = detect_hash_algo(hash_str)
+    pattern = re.compile(SUPPORTED_HASH_ALGOS[hash_name]["REX"])
+    if pattern.match(hash_str):
+        return True
+    else:
+        raise HashStrNotValidException(detected_hash_algo=hash_name, hash_str=hash_str)

tests/test_core.py

@@ -1,5 +1,9 @@
 from unittest import TestCase
+
 from pyntegrity.core import detect_hash_algo
+from pyntegrity.core import validate_hash_str
+
+from pyntegrity.exceptions import HashStrNotValidException
 from pyntegrity.exceptions import HashAlgorithmNotSupportedException
 
 
@@ -16,3 +20,27 @@ def test_detect_hash_algo_nok(self):
         invalid_hash_str = "6545ed"
         with self.assertRaises(HashAlgorithmNotSupportedException):
             detect_hash_algo(invalid_hash_str)
+
+
+class TestValidateHashStr(TestCase):
+    def test_validate_hash_str_md5_ok(self):
+        valid_md5 = "098f6bcd4621d373cade4e832627b4f6"
+        self.assertTrue(validate_hash_str(valid_md5))
+
+    def test_validate_hash_str_md5_nok(self):
+        invalid_md5 = "098f6bcd4621d373xade4e832627b4f6"
+        with self.assertRaises(HashStrNotValidException):
+            validate_hash_str(invalid_md5)
+
+    def test_validate_hash_str_sha256_ok(self):
+        valid_sha256 = (
+            "9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08"
+        )
+        self.assertTrue(validate_hash_str(valid_sha256))
+
+    def test_validate_hash_str_sha256_nok(self):
+        invalid_sha256 = (
+            "9f86d081884x7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08"
+        )
+        with self.assertRaises(HashStrNotValidException):
+            validate_hash_str(invalid_sha256)