Updated script that can be controled by Nodejs web app

lib/python3.13/site-packages/dns/entropy.py

@@ -0,0 +1,130 @@
+# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license
+
+# Copyright (C) 2009-2017 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+import hashlib
+import os
+import random
+import threading
+import time
+from typing import Any, Optional
+
+
+class EntropyPool:
+    # This is an entropy pool for Python implementations that do not
+    # have a working SystemRandom.  I'm not sure there are any, but
+    # leaving this code doesn't hurt anything as the library code
+    # is used if present.
+
+    def __init__(self, seed: Optional[bytes] = None):
+        self.pool_index = 0
+        self.digest: Optional[bytearray] = None
+        self.next_byte = 0
+        self.lock = threading.Lock()
+        self.hash = hashlib.sha1()
+        self.hash_len = 20
+        self.pool = bytearray(b"\0" * self.hash_len)
+        if seed is not None:
+            self._stir(seed)
+            self.seeded = True
+            self.seed_pid = os.getpid()
+        else:
+            self.seeded = False
+            self.seed_pid = 0
+
+    def _stir(self, entropy: bytes) -> None:
+        for c in entropy:
+            if self.pool_index == self.hash_len:
+                self.pool_index = 0
+            b = c & 0xFF
+            self.pool[self.pool_index] ^= b
+            self.pool_index += 1
+
+    def stir(self, entropy: bytes) -> None:
+        with self.lock:
+            self._stir(entropy)
+
+    def _maybe_seed(self) -> None:
+        if not self.seeded or self.seed_pid != os.getpid():
+            try:
+                seed = os.urandom(16)
+            except Exception:  # pragma: no cover
+                try:
+                    with open("/dev/urandom", "rb", 0) as r:
+                        seed = r.read(16)
+                except Exception:
+                    seed = str(time.time()).encode()
+            self.seeded = True
+            self.seed_pid = os.getpid()
+            self.digest = None
+            seed = bytearray(seed)
+            self._stir(seed)
+
+    def random_8(self) -> int:
+        with self.lock:
+            self._maybe_seed()
+            if self.digest is None or self.next_byte == self.hash_len:
+                self.hash.update(bytes(self.pool))
+                self.digest = bytearray(self.hash.digest())
+                self._stir(self.digest)
+                self.next_byte = 0
+            value = self.digest[self.next_byte]
+            self.next_byte += 1
+        return value
+
+    def random_16(self) -> int:
+        return self.random_8() * 256 + self.random_8()
+
+    def random_32(self) -> int:
+        return self.random_16() * 65536 + self.random_16()
+
+    def random_between(self, first: int, last: int) -> int:
+        size = last - first + 1
+        if size > 4294967296:
+            raise ValueError("too big")
+        if size > 65536:
+            rand = self.random_32
+            max = 4294967295
+        elif size > 256:
+            rand = self.random_16
+            max = 65535
+        else:
+            rand = self.random_8
+            max = 255
+        return first + size * rand() // (max + 1)
+
+
+pool = EntropyPool()
+
+system_random: Optional[Any]
+try:
+    system_random = random.SystemRandom()
+except Exception:  # pragma: no cover
+    system_random = None
+
+
+def random_16() -> int:
+    if system_random is not None:
+        return system_random.randrange(0, 65536)
+    else:
+        return pool.random_16()
+
+
+def between(first: int, last: int) -> int:
+    if system_random is not None:
+        return system_random.randrange(first, last + 1)
+    else:
+        return pool.random_between(first, last)