Initial commit. Basic models mostly done.

venv/lib/python3.8/site-packages/django/utils/crypto.py

@@ -0,0 +1,61 @@
+"""
+Django's standard crypto functions and utilities.
+"""
+import hashlib
+import hmac
+import secrets
+
+from django.conf import settings
+from django.utils.encoding import force_bytes
+
+
+def salted_hmac(key_salt, value, secret=None):
+    """
+    Return the HMAC-SHA1 of 'value', using a key generated from key_salt and a
+    secret (which defaults to settings.SECRET_KEY).
+
+    A different key_salt should be passed in for every application of HMAC.
+    """
+    if secret is None:
+        secret = settings.SECRET_KEY
+
+    key_salt = force_bytes(key_salt)
+    secret = force_bytes(secret)
+
+    # We need to generate a derived key from our base key.  We can do this by
+    # passing the key_salt and our base key through a pseudo-random function and
+    # SHA1 works nicely.
+    key = hashlib.sha1(key_salt + secret).digest()
+
+    # If len(key_salt + secret) > sha_constructor().block_size, the above
+    # line is redundant and could be replaced by key = key_salt + secret, since
+    # the hmac module does the same thing for keys longer than the block size.
+    # However, we need to ensure that we *always* do this.
+    return hmac.new(key, msg=force_bytes(value), digestmod=hashlib.sha1)
+
+
+def get_random_string(length=12,
+                      allowed_chars='abcdefghijklmnopqrstuvwxyz'
+                                    'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'):
+    """
+    Return a securely generated random string.
+
+    The default length of 12 with the a-z, A-Z, 0-9 character set returns
+    a 71-bit value. log_2((26+26+10)^12) =~ 71 bits
+    """
+    return ''.join(secrets.choice(allowed_chars) for i in range(length))
+
+
+def constant_time_compare(val1, val2):
+    """Return True if the two strings are equal, False otherwise."""
+    return secrets.compare_digest(force_bytes(val1), force_bytes(val2))
+
+
+def pbkdf2(password, salt, iterations, dklen=0, digest=None):
+    """Return the hash of password using pbkdf2."""
+    if digest is None:
+        digest = hashlib.sha256
+    dklen = dklen or None
+    password = force_bytes(password)
+    salt = force_bytes(salt)
+    return hashlib.pbkdf2_hmac(digest().name, password, salt, iterations, dklen)