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author | Guido van Rossum <guido@python.org> | 2007-05-22 21:56:47 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 2007-05-22 21:56:47 (GMT) |
commit | 4581ae5fa2450db3f00384e4b2e86654605100d4 (patch) | |
tree | 3029bdbbfd3495e4d832036cc17d7ab0bc2f1c02 /Lib/base64.py | |
parent | 0e225aa09bb8059c333424d58beecd833b2d2b6c (diff) | |
download | cpython-4581ae5fa2450db3f00384e4b2e86654605100d4.zip cpython-4581ae5fa2450db3f00384e4b2e86654605100d4.tar.gz cpython-4581ae5fa2450db3f00384e4b2e86654605100d4.tar.bz2 |
Make test_base64 pass.
Change binascii.Error to derive from ValueError
and raise binascii.Error everywhere where values are bad
(why on earth did the old code use TypeError?!?).
Diffstat (limited to 'Lib/base64.py')
-rwxr-xr-x | Lib/base64.py | 255 |
1 files changed, 139 insertions, 116 deletions
diff --git a/Lib/base64.py b/Lib/base64.py index 4eb60f1..de3f184 100755 --- a/Lib/base64.py +++ b/Lib/base64.py @@ -4,6 +4,7 @@ # Modified 04-Oct-1995 by Jack Jansen to use binascii module # Modified 30-Dec-2003 by Barry Warsaw to add full RFC 3548 support +# Modified 22-May-2007 by Guido van Rossum to use bytes everywhere import re import struct @@ -25,122 +26,131 @@ __all__ = [ 'urlsafe_b64encode', 'urlsafe_b64decode', ] -_translation = [chr(_x) for _x in range(256)] -EMPTYSTRING = '' - def _translate(s, altchars): - translation = _translation[:] + assert isinstance(s, bytes), type(s) + translation = bytes(range(256)) for k, v in altchars.items(): - translation[ord(k)] = v - return s.translate(''.join(translation)) + translation[ord(k)] = v[0] + return s.translate(translation) # Base64 encoding/decoding uses binascii def b64encode(s, altchars=None): - """Encode a string using Base64. + """Encode a byte string using Base64. - s is the string to encode. Optional altchars must be a string of at least - length 2 (additional characters are ignored) which specifies an - alternative alphabet for the '+' and '/' characters. This allows an - application to e.g. generate url or filesystem safe Base64 strings. + s is the byte string to encode. Optional altchars must be a byte + string of length 2 which specifies an alternative alphabet for the + '+' and '/' characters. This allows an application to + e.g. generate url or filesystem safe Base64 strings. - The encoded string is returned. + The encoded byte string is returned. """ + if not isinstance(s, bytes): + s = bytes(s) # Strip off the trailing newline encoded = binascii.b2a_base64(s)[:-1] if altchars is not None: - return _translate(encoded, {'+': altchars[0], '/': altchars[1]}) + if not isinstance(altchars, bytes): + altchars = bytes(altchars) + assert len(altchars) == 2, repr(altchars) + return _translate(encoded, {'+': altchars[0:1], '/': altchars[1:2]}) return encoded def b64decode(s, altchars=None): - """Decode a Base64 encoded string. + """Decode a Base64 encoded byte string. - s is the string to decode. Optional altchars must be a string of at least - length 2 (additional characters are ignored) which specifies the - alternative alphabet used instead of the '+' and '/' characters. + s is the byte string to decode. Optional altchars must be a + string of length 2 which specifies the alternative alphabet used + instead of the '+' and '/' characters. - The decoded string is returned. A TypeError is raised if s were - incorrectly padded or if there are non-alphabet characters present in the - string. + The decoded byte string is returned. binascii.Error is raised if + s were incorrectly padded or if there are non-alphabet characters + present in the string. """ + if not isinstance(s, bytes): + s = bytes(s) if altchars is not None: - s = _translate(s, {altchars[0]: '+', altchars[1]: '/'}) - try: - return binascii.a2b_base64(s) - except binascii.Error as msg: - # Transform this exception for consistency - raise TypeError(msg) + if not isinstance(altchars, bytes): + altchars = bytes(altchars) + assert len(altchars) == 2, repr(altchars) + s = _translate(s, {chr(altchars[0]): b'+', chr(altchars[1]): b'/'}) + return binascii.a2b_base64(s) def standard_b64encode(s): - """Encode a string using the standard Base64 alphabet. + """Encode a byte string using the standard Base64 alphabet. - s is the string to encode. The encoded string is returned. + s is the byte string to encode. The encoded byte string is returned. """ return b64encode(s) def standard_b64decode(s): - """Decode a string encoded with the standard Base64 alphabet. + """Decode a byte string encoded with the standard Base64 alphabet. - s is the string to decode. The decoded string is returned. A TypeError - is raised if the string is incorrectly padded or if there are non-alphabet - characters present in the string. + s is the byte string to decode. The decoded byte string is + returned. binascii.Error is raised if the input is incorrectly + padded or if there are non-alphabet characters present in the + input. """ return b64decode(s) def urlsafe_b64encode(s): - """Encode a string using a url-safe Base64 alphabet. + """Encode a byte string using a url-safe Base64 alphabet. - s is the string to encode. The encoded string is returned. The alphabet - uses '-' instead of '+' and '_' instead of '/'. + s is the byte string to encode. The encoded byte string is + returned. The alphabet uses '-' instead of '+' and '_' instead of + '/'. """ - return b64encode(s, '-_') + return b64encode(s, b'-_') def urlsafe_b64decode(s): - """Decode a string encoded with the standard Base64 alphabet. + """Decode a byte string encoded with the standard Base64 alphabet. - s is the string to decode. The decoded string is returned. A TypeError - is raised if the string is incorrectly padded or if there are non-alphabet - characters present in the string. + s is the byte string to decode. The decoded byte string is + returned. binascii.Error is raised if the input is incorrectly + padded or if there are non-alphabet characters present in the + input. The alphabet uses '-' instead of '+' and '_' instead of '/'. """ - return b64decode(s, '-_') + return b64decode(s, b'-_') # Base32 encoding/decoding must be done in Python _b32alphabet = { - 0: 'A', 9: 'J', 18: 'S', 27: '3', - 1: 'B', 10: 'K', 19: 'T', 28: '4', - 2: 'C', 11: 'L', 20: 'U', 29: '5', - 3: 'D', 12: 'M', 21: 'V', 30: '6', - 4: 'E', 13: 'N', 22: 'W', 31: '7', - 5: 'F', 14: 'O', 23: 'X', - 6: 'G', 15: 'P', 24: 'Y', - 7: 'H', 16: 'Q', 25: 'Z', - 8: 'I', 17: 'R', 26: '2', + 0: b'A', 9: b'J', 18: b'S', 27: b'3', + 1: b'B', 10: b'K', 19: b'T', 28: b'4', + 2: b'C', 11: b'L', 20: b'U', 29: b'5', + 3: b'D', 12: b'M', 21: b'V', 30: b'6', + 4: b'E', 13: b'N', 22: b'W', 31: b'7', + 5: b'F', 14: b'O', 23: b'X', + 6: b'G', 15: b'P', 24: b'Y', + 7: b'H', 16: b'Q', 25: b'Z', + 8: b'I', 17: b'R', 26: b'2', } -_b32tab = [v for k, v in sorted(_b32alphabet.items())] -_b32rev = dict([(v, int(k)) for k, v in _b32alphabet.items()]) +_b32tab = [v[0] for k, v in sorted(_b32alphabet.items())] +_b32rev = dict([(v[0], k) for k, v in _b32alphabet.items()]) def b32encode(s): - """Encode a string using Base32. + """Encode a byte string using Base32. - s is the string to encode. The encoded string is returned. + s is the byte string to encode. The encoded byte string is returned. """ - parts = [] + if not isinstance(s, bytes): + s = bytes(s) quanta, leftover = divmod(len(s), 5) # Pad the last quantum with zero bits if necessary if leftover: - s += ('\0' * (5 - leftover)) + s = s + bytes(5 - leftover) # Don't use += ! quanta += 1 + encoded = bytes() for i in range(quanta): # c1 and c2 are 16 bits wide, c3 is 8 bits wide. The intent of this # code is to process the 40 bits in units of 5 bits. So we take the 1 @@ -150,57 +160,61 @@ def b32encode(s): c1, c2, c3 = struct.unpack('!HHB', s[i*5:(i+1)*5]) c2 += (c1 & 1) << 16 # 17 bits wide c3 += (c2 & 3) << 8 # 10 bits wide - parts.extend([_b32tab[c1 >> 11], # bits 1 - 5 - _b32tab[(c1 >> 6) & 0x1f], # bits 6 - 10 - _b32tab[(c1 >> 1) & 0x1f], # bits 11 - 15 - _b32tab[c2 >> 12], # bits 16 - 20 (1 - 5) - _b32tab[(c2 >> 7) & 0x1f], # bits 21 - 25 (6 - 10) - _b32tab[(c2 >> 2) & 0x1f], # bits 26 - 30 (11 - 15) - _b32tab[c3 >> 5], # bits 31 - 35 (1 - 5) - _b32tab[c3 & 0x1f], # bits 36 - 40 (1 - 5) - ]) - encoded = EMPTYSTRING.join(parts) + encoded += bytes([_b32tab[c1 >> 11], # bits 1 - 5 + _b32tab[(c1 >> 6) & 0x1f], # bits 6 - 10 + _b32tab[(c1 >> 1) & 0x1f], # bits 11 - 15 + _b32tab[c2 >> 12], # bits 16 - 20 (1 - 5) + _b32tab[(c2 >> 7) & 0x1f], # bits 21 - 25 (6 - 10) + _b32tab[(c2 >> 2) & 0x1f], # bits 26 - 30 (11 - 15) + _b32tab[c3 >> 5], # bits 31 - 35 (1 - 5) + _b32tab[c3 & 0x1f], # bits 36 - 40 (1 - 5) + ]) # Adjust for any leftover partial quanta if leftover == 1: - return encoded[:-6] + '======' + return encoded[:-6] + b'======' elif leftover == 2: - return encoded[:-4] + '====' + return encoded[:-4] + b'====' elif leftover == 3: - return encoded[:-3] + '===' + return encoded[:-3] + b'===' elif leftover == 4: - return encoded[:-1] + '=' + return encoded[:-1] + b'=' return encoded def b32decode(s, casefold=False, map01=None): - """Decode a Base32 encoded string. - - s is the string to decode. 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 decoded string is returned. A TypeError is raised if s were - incorrectly padded or if there are non-alphabet characters present in the - string. + """Decode a Base32 encoded byte string. + + s is the byte string to decode. 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 decoded byte string is returned. binascii.Error is raised if + the input is incorrectly padded or if there are non-alphabet + characters present in the input. """ + if not isinstance(s, bytes): + s = bytes(s) quanta, leftover = divmod(len(s), 8) if leftover: - raise TypeError('Incorrect padding') + raise binascii.Error('Incorrect padding') # Handle section 2.4 zero and one mapping. The flag map01 will be either # False, or the character to map the digit 1 (one) to. It should be # either L (el) or I (eye). if map01: - s = _translate(s, {'0': 'O', '1': map01}) + if not isinstance(map01, bytes): + map01 = bytes(map01) + assert len(map01) == 1, repr(map01) + s = _translate(s, {'0': b'O', '1': map01}) if casefold: - s = s.upper() + s = bytes(str(s, "ascii").upper(), "ascii") # Strip off pad characters from the right. We need to count the pad # characters because this will tell us how many null bytes to remove from # the end of the decoded string. @@ -225,9 +239,9 @@ def b32decode(s, casefold=False, map01=None): acc = 0 shift = 35 # Process the last, partial quanta - last = binascii.unhexlify('%010x' % acc) + last = binascii.unhexlify(bytes('%010x' % acc)) if padchars == 0: - last = '' # No characters + last = b'' # No characters elif padchars == 1: last = last[:-1] elif padchars == 3: @@ -237,9 +251,9 @@ def b32decode(s, casefold=False, map01=None): elif padchars == 6: last = last[:-4] else: - raise TypeError('Incorrect padding') + raise binascii.Error('Incorrect padding') parts.append(last) - return EMPTYSTRING.join(parts) + return b''.join(parts) @@ -247,35 +261,37 @@ def b32decode(s, casefold=False, map01=None): # lowercase. The RFC also recommends against accepting input case # insensitively. def b16encode(s): - """Encode a string using Base16. + """Encode a byte string using Base16. - s is the string to encode. The encoded string is returned. + s is the byte string to encode. The encoded byte string is returned. """ - return binascii.hexlify(s).upper() + return bytes(str(binascii.hexlify(s), "ascii").upper(), "ascii") def b16decode(s, casefold=False): - """Decode a Base16 encoded string. + """Decode a Base16 encoded byte string. - s is the string to decode. Optional casefold is a flag specifying whether - a lowercase alphabet is acceptable as input. For security purposes, the - default is False. + s is the byte string to decode. Optional casefold is a flag + specifying whether a lowercase alphabet is acceptable as input. + For security purposes, the default is False. - The decoded string is returned. A TypeError is raised if s were - incorrectly padded or if there are non-alphabet characters present in the - string. + The decoded byte string is returned. binascii.Error is raised if + s were incorrectly padded or if there are non-alphabet characters + present in the string. """ + if not isinstance(s, bytes): + s = bytes(s) if casefold: - s = s.upper() + s = bytes(str(s, "ascii").upper(), "ascii") if re.search('[^0-9A-F]', s): - raise TypeError('Non-base16 digit found') + raise binascii.Error('Non-base16 digit found') return binascii.unhexlify(s) # Legacy interface. This code could be cleaned up since I don't believe # binascii has any line length limitations. It just doesn't seem worth it -# though. +# though. The files should be opened in binary mode. MAXLINESIZE = 76 # Excluding the CRLF MAXBINSIZE = (MAXLINESIZE//4)*3 @@ -307,22 +323,26 @@ def decode(input, output): def encodestring(s): """Encode a string into multiple lines of base-64 data.""" + if not isinstance(s, bytes): + s = bytes(s) pieces = [] for i in range(0, len(s), MAXBINSIZE): chunk = s[i : i + MAXBINSIZE] pieces.append(binascii.b2a_base64(chunk)) - return "".join(pieces) + return b"".join(pieces) def decodestring(s): """Decode a string.""" + if not isinstance(s, bytes): + s = bytes(s) return binascii.a2b_base64(s) -# Useable as a script... -def test(): - """Small test program""" +# Usable as a script... +def main(): + """Small main program""" import sys, getopt try: opts, args = getopt.getopt(sys.argv[1:], 'deut') @@ -339,19 +359,22 @@ def test(): if o == '-e': func = encode if o == '-d': func = decode if o == '-u': func = decode - if o == '-t': test1(); return + if o == '-t': test(); return if args and args[0] != '-': func(open(args[0], 'rb'), sys.stdout) else: func(sys.stdin, sys.stdout) -def test1(): - s0 = "Aladdin:open sesame" +def test(): + s0 = b"Aladdin:open sesame" + print(repr(s0)) s1 = encodestring(s0) + print(repr(s1)) s2 = decodestring(s1) - print(s0, repr(s1), s2) + print(repr(s2)) + assert s0 == s2 if __name__ == '__main__': - test() + main() |