[mod] #301 : create a function gen_checksum

    * gets a pubkey in for input
    * returns the checksum

silkaj/crypto_tools.py

@@ -35,12 +35,7 @@ def check_public_key(pubkey, display_error):
         return pubkey
     elif re.search(re.compile(PUBKEY_CHECKSUM_PATTERN), pubkey):
         pubkey, checksum = pubkey.split(":")
-        pubkey_byte = b58_decode(pubkey)
-        checksum_calculed = b58_encode(
-            hash.sha256(
-                hash.sha256(pubkey_byte, encoding.RawEncoder), encoding.RawEncoder
-            )
-        )[:3]
+        checksum_calculed = gen_checksum(pubkey)
         if checksum_calculed == checksum:
             return pubkey
         else:
@@ -52,6 +47,16 @@ def check_public_key(pubkey, display_error):
     return False
 
 
+def gen_checksum(pubkey):
+    """
+    Returns the checksum of the input pubkey (encoded in b58)
+    """
+    pubkey_byte = b58_decode(pubkey)
+    return b58_encode(
+        hash.sha256(hash.sha256(pubkey_byte, encoding.RawEncoder), encoding.RawEncoder)
+    )[:3]
+
+
 b58_digits = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz"
 
 

tests/test_crypto_tools.py

+"""
+Copyright  2016-2020 Maël Azimi <m.a@moul.re>
+
+Silkaj is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+Silkaj is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with Silkaj. If not, see <https://www.gnu.org/licenses/>.
+"""
+
+import pytest
+
+from silkaj import crypto_tools
+
+
+@pytest.mark.parametrize(
+    "pubkey, checksum",
+    [
+        ("J4c8CARmP9vAFNGtHRuzx14zvxojyRWHW2darguVqjtX", "KAv"),
+    ],
+)
+def test_gen_checksum(pubkey, checksum):
+    assert checksum == crypto_tools.gen_checksum(pubkey)