Update base64.py and test_base64.py from CPython v3.11.2

Author: MegasKomnenos

Lib/base64.py

@@ -1,4 +1,4 @@
-#! /usr/bin/python3.6
+#! /usr/bin/env python3
 
 """Base16, Base32, Base64 (RFC 3548), Base85 and Ascii85 data encodings"""
 
@@ -16,7 +16,7 @@
     'encode', 'decode', 'encodebytes', 'decodebytes',
     # Generalized interface for other encodings
     'b64encode', 'b64decode', 'b32encode', 'b32decode',
-    'b16encode', 'b16decode',
+    'b32hexencode', 'b32hexdecode', 'b16encode', 'b16decode',
     # Base85 and Ascii85 encodings
     'b85encode', 'b85decode', 'a85encode', 'a85decode',
     # Standard Base64 encoding
@@ -76,15 +76,16 @@ def b64decode(s, altchars=None, validate=False):
     normal base-64 alphabet nor the alternative alphabet are discarded prior
     to the padding check.  If validate is True, these non-alphabet characters
     in the input result in a binascii.Error.
+    For more information about the strict base64 check, see:
+
+    https://docs.python.org/3.11/library/binascii.html#binascii.a2b_base64
     """
     s = _bytes_from_decode_data(s)
     if altchars is not None:
         altchars = _bytes_from_decode_data(altchars)
         assert len(altchars) == 2, repr(altchars)
         s = s.translate(bytes.maketrans(altchars, b'+/'))
-    if validate and not re.match(b'^[A-Za-z0-9+/]*={0,2}$', s):
-        raise binascii.Error('Non-base64 digit found')
-    return binascii.a2b_base64(s)
+    return binascii.a2b_base64(s, strict_mode=validate)
 
 
 def standard_b64encode(s):
@@ -135,19 +136,40 @@ def urlsafe_b64decode(s):
 
 
 # Base32 encoding/decoding must be done in Python
+_B32_ENCODE_DOCSTRING = '''
+Encode the bytes-like objects using {encoding} and return a bytes object.
+'''
+_B32_DECODE_DOCSTRING = '''
+Decode the {encoding} encoded bytes-like object or ASCII string s.
+
+Optional casefold is a flag specifying whether a lowercase alphabet is
+acceptable as input.  For security purposes, the default is False.
+{extra_args}
+The result is returned as a bytes object.  A binascii.Error is raised if
+the input is incorrectly padded or if there are non-alphabet
+characters present in the input.
+'''
+_B32_DECODE_MAP01_DOCSTRING = '''
+RFC 3548 allows for optional mapping of the digit 0 (zero) to the
+letter O (oh), and for optional mapping of the digit 1 (one) to
+either the letter I (eye) or letter L (el).  The optional argument
+map01 when not None, specifies which letter the digit 1 should be
+mapped to (when map01 is not None, the digit 0 is always mapped to
+the letter O).  For security purposes the default is None, so that
+0 and 1 are not allowed in the input.
+'''
 _b32alphabet = b'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567'
-_b32tab2 = None
-_b32rev = None
+_b32hexalphabet = b'0123456789ABCDEFGHIJKLMNOPQRSTUV'
+_b32tab2 = {}
+_b32rev = {}
 
-def b32encode(s):
-    """Encode the bytes-like object s using Base32 and return a bytes object.
-    """
+def _b32encode(alphabet, s):
     global _b32tab2
     # Delay the initialization of the table to not waste memory
     # if the function is never called
-    if _b32tab2 is None:
-        b32tab = [bytes((i,)) for i in _b32alphabet]
-        _b32tab2 = [a + b for a in b32tab for b in b32tab]
+    if alphabet not in _b32tab2:
+        b32tab = [bytes((i,)) for i in alphabet]
+        _b32tab2[alphabet] = [a + b for a in b32tab for b in b32tab]
         b32tab = None
 
     if not isinstance(s, bytes_types):
@@ -158,9 +180,9 @@ def b32encode(s):
         s = s + b'\0' * (5 - leftover)  # Don't use += !
     encoded = bytearray()
     from_bytes = int.from_bytes
-    b32tab2 = _b32tab2
+    b32tab2 = _b32tab2[alphabet]
     for i in range(0, len(s), 5):
-        c = from_bytes(s[i: i + 5], 'big')
+        c = from_bytes(s[i: i + 5])              # big endian
         encoded += (b32tab2[c >> 30] +           # bits 1 - 10
                     b32tab2[(c >> 20) & 0x3ff] + # bits 11 - 20
                     b32tab2[(c >> 10) & 0x3ff] + # bits 21 - 30
@@ -177,29 +199,12 @@ def b32encode(s):
         encoded[-1:] = b'='
     return bytes(encoded)
 
-def b32decode(s, casefold=False, map01=None):
-    """Decode the Base32 encoded bytes-like object or ASCII string s.
-
-    Optional casefold is a flag specifying whether a lowercase alphabet is
-    acceptable as input.  For security purposes, the default is False.
-
-    RFC 3548 allows for optional mapping of the digit 0 (zero) to the
-    letter O (oh), and for optional mapping of the digit 1 (one) to
-    either the letter I (eye) or letter L (el).  The optional argument
-    map01 when not None, specifies which letter the digit 1 should be
-    mapped to (when map01 is not None, the digit 0 is always mapped to
-    the letter O).  For security purposes the default is None, so that
-    0 and 1 are not allowed in the input.
-
-    The result is returned as a bytes object.  A binascii.Error is raised if
-    the input is incorrectly padded or if there are non-alphabet
-    characters present in the input.
-    """
+def _b32decode(alphabet, s, casefold=False, map01=None):
     global _b32rev
     # Delay the initialization of the table to not waste memory
     # if the function is never called
-    if _b32rev is None:
-        _b32rev = {v: k for k, v in enumerate(_b32alphabet)}
+    if alphabet not in _b32rev:
+        _b32rev[alphabet] = {v: k for k, v in enumerate(alphabet)}
     s = _bytes_from_decode_data(s)
     if len(s) % 8:
         raise binascii.Error('Incorrect padding')
@@ -220,7 +225,7 @@ def b32decode(s, casefold=False, map01=None):
     padchars = l - len(s)
     # Now decode the full quanta
     decoded = bytearray()
-    b32rev = _b32rev
+    b32rev = _b32rev[alphabet]
     for i in range(0, len(s), 8):
         quanta = s[i: i + 8]
         acc = 0
@@ -229,18 +234,38 @@ def b32decode(s, casefold=False, map01=None):
                 acc = (acc << 5) + b32rev[c]
         except KeyError:
             raise binascii.Error('Non-base32 digit found') from None
-        decoded += acc.to_bytes(5, 'big')
+        decoded += acc.to_bytes(5)  # big endian
     # Process the last, partial quanta
     if l % 8 or padchars not in {0, 1, 3, 4, 6}:
         raise binascii.Error('Incorrect padding')
     if padchars and decoded:
         acc <<= 5 * padchars
-        last = acc.to_bytes(5, 'big')
+        last = acc.to_bytes(5)  # big endian
         leftover = (43 - 5 * padchars) // 8  # 1: 4, 3: 3, 4: 2, 6: 1
         decoded[-5:] = last[:leftover]
     return bytes(decoded)
 
 
+def b32encode(s):
+    return _b32encode(_b32alphabet, s)
+b32encode.__doc__ = _B32_ENCODE_DOCSTRING.format(encoding='base32')
+
+def b32decode(s, casefold=False, map01=None):
+    return _b32decode(_b32alphabet, s, casefold, map01)
+b32decode.__doc__ = _B32_DECODE_DOCSTRING.format(encoding='base32',
+                                        extra_args=_B32_DECODE_MAP01_DOCSTRING)
+
+def b32hexencode(s):
+    return _b32encode(_b32hexalphabet, s)
+b32hexencode.__doc__ = _B32_ENCODE_DOCSTRING.format(encoding='base32hex')
+
+def b32hexdecode(s, casefold=False):
+    # base32hex does not have the 01 mapping
+    return _b32decode(_b32hexalphabet, s, casefold)
+b32hexdecode.__doc__ = _B32_DECODE_DOCSTRING.format(encoding='base32hex',
+                                                    extra_args='')
+
+
 # RFC 3548, Base 16 Alphabet specifies uppercase, but hexlify() returns
 # lowercase.  The RFC also recommends against accepting input case
 # insensitively.
@@ -320,7 +345,7 @@ def a85encode(b, *, foldspaces=False, wrapcol=0, pad=False, adobe=False):
     global _a85chars, _a85chars2
     # Delay the initialization of tables to not waste memory
     # if the function is never called
-    if _a85chars is None:
+    if _a85chars2 is None:
         _a85chars = [bytes((i,)) for i in range(33, 118)]
         _a85chars2 = [(a + b) for a in _a85chars for b in _a85chars]
 
@@ -428,7 +453,7 @@ def b85encode(b, pad=False):
     global _b85chars, _b85chars2
     # Delay the initialization of tables to not waste memory
     # if the function is never called
-    if _b85chars is None:
+    if _b85chars2 is None:
         _b85chars = [bytes((i,)) for i in _b85alphabet]
         _b85chars2 = [(a + b) for a in _b85chars for b in _b85chars]
     return _85encode(b, _b85chars, _b85chars2, pad)
@@ -531,49 +556,36 @@ def encodebytes(s):
         pieces.append(binascii.b2a_base64(chunk))
     return b"".join(pieces)
 
-def encodestring(s):
-    """Legacy alias of encodebytes()."""
-    import warnings
-    warnings.warn("encodestring() is a deprecated alias since 3.1, "
-                  "use encodebytes()",
-                  DeprecationWarning, 2)
-    return encodebytes(s)
-
 
 def decodebytes(s):
     """Decode a bytestring of base-64 data into a bytes object."""
     _input_type_check(s)
     return binascii.a2b_base64(s)
 
-def decodestring(s):
-    """Legacy alias of decodebytes()."""
-    import warnings
-    warnings.warn("decodestring() is a deprecated alias since Python 3.1, "
-                  "use decodebytes()",
-                  DeprecationWarning, 2)
-    return decodebytes(s)
-
 
 # Usable as a script...
 def main():
     """Small main program"""
     import sys, getopt
+    usage = """usage: %s [-h|-d|-e|-u|-t] [file|-]
+        -h: print this help message and exit
+        -d, -u: decode
+        -e: encode (default)
+        -t: encode and decode string 'Aladdin:open sesame'"""%sys.argv[0]
     try:
-        opts, args = getopt.getopt(sys.argv[1:], 'deut')
+        opts, args = getopt.getopt(sys.argv[1:], 'hdeut')
     except getopt.error as msg:
         sys.stdout = sys.stderr
         print(msg)
-        print("""usage: %s [-d|-e|-u|-t] [file|-]
-        -d, -u: decode
-        -e: encode (default)
-        -t: encode and decode string 'Aladdin:open sesame'"""%sys.argv[0])
+        print(usage)
         sys.exit(2)
     func = encode
     for o, a in opts:
         if o == '-e': func = encode
         if o == '-d': func = decode
         if o == '-u': func = decode
         if o == '-t': test(); return
+        if o == '-h': print(usage); return
     if args and args[0] != '-':
         with open(args[0], 'rb') as f:
             func(f, sys.stdout.buffer)