delete new function rand_str_minclass, optimize rand_user_password

Co-authored-by: shixuantong <shixuantong1@huawei.com>
Co-authored-by: James Falcon <james.falcon@canonical.com>

cloudinit/config/cc_set_passwords.py

@@ -8,8 +8,9 @@
 """Set Passwords: Set user passwords and enable/disable SSH password auth"""
 
 import logging
+import random
 import re
-from string import ascii_letters, digits
+import string
 from typing import List
 
 from cloudinit import features, lifecycle, subp, util
@@ -30,9 +31,6 @@
 
 LOG = logging.getLogger(__name__)
 
-# We are removing certain 'painful' letters/numbers
-PW_SET = "".join([x for x in ascii_letters + digits if x not in "loLOI01"])
-
 
 def get_users_by_type(users_list: list, pw_type: str) -> list:
     """either password or type: RANDOM is required, user is always required"""
@@ -248,4 +246,29 @@ def handle(name: str, cfg: Config, cloud: Cloud, args: list) -> None:
 
 
 def rand_user_password(pwlen=20):
-    return util.rand_str_minclass(pwlen, minclass=3, select_from=PW_SET)
+    if pwlen < 4:
+        raise ValueError("Password length must be at least 4 characters.")
+
+    # There are often restrictions on the minimum number of character
+    # classes required in a password, so ensure we at least one character
+    # from each class.
+    res_rand_list = [
+        random.choice(string.digits),
+        random.choice(string.ascii_lowercase),
+        random.choice(string.ascii_uppercase),
+        random.choice(string.punctuation),
+    ]
+
+    res_rand_list.extend(
+        list(
+            util.rand_str(
+                pwlen - len(res_rand_list),
+                select_from=string.digits
+                + string.ascii_lowercase
+                + string.ascii_uppercase
+                + string.punctuation,
+            )
+        )
+    )
+    random.shuffle(res_rand_list)
+    return "".join(res_rand_list)

cloudinit/util.py

@@ -299,31 +299,6 @@ def rand_str(strlen=32, select_from=None):
     return "".join([r.choice(select_from) for _x in range(strlen)])
 
 
-def rand_str_minclass(strlen=32, minclass=3, select_from=None):
-    if strlen <= 0:
-        strlen = 32
-        LOG.warning("strlen <= 0, use default value(32)")
-
-    if minclass <= 0:
-        minclass = 3
-        LOG.warning("minclass <= 0, use default value(3)")
-
-    res_rand_list = [
-        random.choice(string.digits),
-        random.choice(string.ascii_lowercase),
-        random.choice(string.ascii_uppercase),
-    ]
-    if minclass > 3:
-        res_rand_list.append(random.choice(string.punctuation))
-        if select_from:
-            select_from += string.punctuation
-
-    res_rand_list = random.sample(res_rand_list, min(minclass, strlen, 4))
-    res_rand_list.extend(list(rand_str(strlen - minclass, select_from)))
-    random.shuffle(res_rand_list)
-    return "".join(res_rand_list)
-
-
 def rand_dict_key(dictionary, postfix=None):
     if not postfix:
         postfix = ""

tests/unittests/config/test_cc_set_passwords.py

@@ -2,6 +2,7 @@
 
 import copy
 import logging
+import string
 from unittest import mock
 
 import pytest
@@ -559,6 +560,40 @@ def test_expire_old_behavior(self, cfg, mocker, caplog):
             assert "Expired passwords" not in caplog.text
 
 
+class TestRandUserPassword:
+    def _get_str_class_num(self, str):
+        return sum(
+            [
+                any(c.islower() for c in str),
+                any(c.isupper() for c in str),
+                any(c.isupper() for c in str),
+                any(c in string.punctuation for c in str),
+            ]
+        )
+
+    @pytest.mark.parametrize(
+        "strlen, expected_result",
+        [
+            (1, ValueError),
+            (2, ValueError),
+            (3, ValueError),
+            (4, 4),
+            (5, 4),
+            (5, 4),
+            (6, 4),
+            (20, 4),
+        ],
+    )
+    def test_get_str_class_num(self, strlen, expected_result):
+        if expected_result is ValueError:
+            with pytest.raises(expected_result):
+                setpass.rand_user_password(strlen)
+        else:
+            rand_password = setpass.rand_user_password(strlen)
+            assert len(rand_password) == strlen
+            assert self._get_str_class_num(rand_password) == expected_result
+
+
 class TestSetPasswordsSchema:
     @pytest.mark.parametrize(
         "config, expectation",

tests/unittests/test_util.py

@@ -3369,64 +3369,3 @@ def test_logexc_with_log_level(self, caplog, log_level):
             ),
             ("tests.unittests.test_util", logging.DEBUG, "an error occurred"),
         ]
-
-
-class TestRandStr:
-    def _get_str_class_num(self, str):
-        import string
-
-        str_class_num = 0
-        if any(c.islower() for c in str):
-            str_class_num += 1
-        if any(c.isupper() for c in str):
-            str_class_num += 1
-        if any(c.isdigit() for c in str):
-            str_class_num += 1
-        if any(c in string.punctuation for c in str):
-            str_class_num += 1
-        return str_class_num
-
-    @pytest.mark.parametrize(
-        "strlen, param_minclass, expected_minclass, expected_maxclass",
-        [
-            (1, 1, 1, 1),
-            (1, 2, 1, 1),
-            (1, 3, 1, 1),
-            (1, 4, 1, 1),
-            (2, 1, 1, 2),
-            (2, 2, 2, 2),
-            (2, 3, 2, 2),
-            (2, 4, 2, 2),
-            (3, 1, 1, 3),
-            (3, 2, 2, 3),
-            (3, 3, 3, 3),
-            (3, 4, 3, 3),
-            (4, 1, 1, 3),
-            (4, 2, 2, 3),
-            (4, 3, 3, 3),
-            (4, 4, 4, 4),
-            (5, 1, 1, 3),
-            (5, 2, 2, 3),
-            (5, 3, 3, 3),
-            (5, 4, 4, 4),
-            (5, 5, 4, 4),
-            (6, 1, 1, 3),
-            (6, 2, 2, 3),
-            (6, 3, 3, 3),
-            (6, 4, 4, 4),
-            (6, 5, 4, 4),
-            (6, 6, 4, 4),
-            (20, 1, 1, 3),
-            (20, 2, 2, 3),
-            (20, 3, 3, 3),
-            (20, 4, 4, 4),
-            (20, 5, 4, 4),
-        ],
-    )
-    def test_get_str_class_num(
-        self, strlen, param_minclass, expected_minclass, expected_maxclass
-    ):
-        res_rand_str = util.rand_str_minclass(strlen, param_minclass)
-        actual_class = self._get_str_class_num(res_rand_str)
-        assert actual_class >= expected_minclass
-        assert actual_class <= expected_maxclass