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Diffstat (limited to 'passlib/utils/h64.py')
| -rw-r--r-- | passlib/utils/h64.py | 286 |
1 files changed, 0 insertions, 286 deletions
diff --git a/passlib/utils/h64.py b/passlib/utils/h64.py deleted file mode 100644 index cf889d3..0000000 --- a/passlib/utils/h64.py +++ /dev/null @@ -1,286 +0,0 @@ -"""passlib.utils.h64 - hash64 encoding helpers""" -#================================================================================= -#imports -#================================================================================= -#core -import logging; log = logging.getLogger(__name__) -#site -#pkg -from passlib.utils import bytes, bjoin, bord, bjoin_elems, bjoin_ints -from passlib.utils.compat import irange, u, PY3 -#local -__all__ = [ - "CHARS", - - "decode_bytes", "encode_bytes", - "decode_transposed_bytes", "encode_transposed_bytes", - - "decode_int6", "encode_int6", - "decode_int12", "encode_int12" - "decode_int18", "encode_int18" - "decode_int24", "encode_int24", - "decode_int64", "encode_int64", - "decode_int", "encode_int", -] - -#================================================================================= -#6 bit value <-> char mapping, and other internal helpers -#================================================================================= - -#: hash64 char sequence -CHARS = u("./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz") -BCHARS = CHARS.encode("ascii") - -#: encode int -> hash64 char as efficiently as possible, w/ minimal checking -if PY3: - _encode_6bit = lambda v: BCHARS[v:v+1] -else: - _encode_6bit = BCHARS.__getitem__ - -#: decode hash64 char -> int as efficiently as possible, w/ minimal checking -_CHARIDX = dict((_encode_6bit(i),i) for i in irange(64)) -_decode_6bit = _CHARIDX.__getitem__ # char -> int - -#for py3, enhance _CHARIDX to also support int value of bytes -if PY3: - _CHARIDX.update((v,i) for i,v in enumerate(BCHARS)) - -#================================================================================= -#encode offsets from buffer - used by md5_crypt, sha_crypt, et al -#================================================================================= - -def _encode_bytes_helper(source): - #FIXME: do something much more efficient here. - # can't quite just use base64 and then translate chars, - # since this scheme is little-endian. - end = len(source) - tail = end % 3 - end -= tail - idx = 0 - while idx < end: - v1 = bord(source[idx]) - v2 = bord(source[idx+1]) - v3 = bord(source[idx+2]) - yield encode_int24(v1 + (v2<<8) + (v3<<16)) - idx += 3 - if tail: - v1 = bord(source[idx]) - if tail == 1: - #NOTE: 4 msb of int are always 0 - yield encode_int12(v1) - else: - #NOTE: 2 msb of int are always 0 - v2 = bord(source[idx+1]) - yield encode_int18(v1 + (v2<<8)) - -def encode_bytes(source): - "encode byte string to h64 format" - if not isinstance(source, bytes): - raise TypeError("source must be bytes, not %s" % (type(source),)) - return bjoin(_encode_bytes_helper(source)) - -def _decode_bytes_helper(source): - end = len(source) - tail = end % 4 - if tail == 1: - #only 6 bits left, can't encode a whole byte! - raise ValueError("input string length cannot be == 1 mod 4") - end -= tail - idx = 0 - while idx < end: - v = decode_int24(source[idx:idx+4]) - yield bjoin_ints([v&0xff, (v>>8)&0xff, v>>16]) - idx += 4 - if tail: - if tail == 2: - #NOTE: 2 msb of int are ignored (should be 0) - v = decode_int12(source[idx:idx+2]) - yield bjoin_ints([v&0xff]) - else: - #NOTE: 4 msb of int are ignored (should be 0) - v = decode_int18(source[idx:idx+3]) - yield bjoin_ints([v&0xff, (v>>8)&0xff]) - -def decode_bytes(source): - "decode h64 format into byte string" - if not isinstance(source, bytes): - raise TypeError("source must be bytes, not %s" % (type(source),)) - return bjoin(_decode_bytes_helper(source)) - -def encode_transposed_bytes(source, offsets): - "encode byte string to h64 format, using offset list to transpose elements" - if not isinstance(source, bytes): - raise TypeError("source must be bytes, not %s" % (type(source),)) - #XXX: could make this a dup of encode_bytes(), which directly accesses source[offsets[idx]], - # but speed isn't *that* critical for this function - tmp = bjoin_elems(source[off] for off in offsets) - return encode_bytes(tmp) - -def decode_transposed_bytes(source, offsets): - "decode h64 format into byte string, then undoing specified transposition; inverse of :func:`encode_transposed_bytes`" - #NOTE: if transposition does not use all bytes of source, original can't be recovered - tmp = decode_bytes(source) - buf = [None] * len(offsets) - for off, char in zip(offsets, tmp): - buf[off] = char - return bjoin_elems(buf) - -#================================================================================= -# int <-> b64 string, used by des_crypt, bsdi_crypt -#================================================================================= - -def decode_int6(source): - "decodes single hash64 character -> 6-bit integer" - if not isinstance(source, bytes): - raise TypeError("source must be bytes, not %s" % (type(source),)) - try: - return _decode_6bit(source) - except KeyError: - raise ValueError("invalid character") - -def encode_int6(value): - "encodes 6-bit integer -> single hash64 character" - if value < 0 or value > 63: - raise ValueError("value out of range") - return _encode_6bit(value) - -#--------------------------------------------------------------------- - -def decode_int12(source): - "decodes 2 char hash64 string -> 12-bit integer (little-endian order)" - #NOTE: this is optimized form of decode_int(value) for 4 chars - if not isinstance(source, bytes): - raise TypeError("source must be bytes, not %s" % (type(source),)) - try: - return (_decode_6bit(source[1])<<6)+_decode_6bit(source[0]) - except KeyError: - raise ValueError("invalid character") - -def encode_int12(value): - "encodes 12-bit integer -> 2 char hash64 string (little-endian order)" - #NOTE: this is optimized form of encode_int(value,2) - return _encode_6bit(value & 0x3f) + _encode_6bit((value>>6) & 0x3f) - -#--------------------------------------------------------------------- -def decode_int18(source): - "decodes 3 char hash64 string -> 18-bit integer (little-endian order)" - #NOTE: this is optimized form of decode_int(value) for 3 chars - if not isinstance(source, bytes): - raise TypeError("source must be bytes, not %s" % (type(source),)) - return ( - _decode_6bit(source[0]) + - (_decode_6bit(source[1])<<6) + - (_decode_6bit(source[2])<<12) - ) - -def encode_int18(value): - "encodes 18-bit integer -> 3 char hash64 string (little-endian order)" - #NOTE: this is optimized form of encode_int(value,3) - return ( - _encode_6bit(value & 0x3f) + - _encode_6bit((value>>6) & 0x3f) + - _encode_6bit((value>>12) & 0x3f) - ) - -#--------------------------------------------------------------------- - -def decode_int24(source): - "decodes 4 char hash64 string -> 24-bit integer (little-endian order)" - #NOTE: this is optimized form of decode_int(source) for 4 chars - if not isinstance(source, bytes): - raise TypeError("source must be bytes, not %s" % (type(source),)) - try: - return _decode_6bit(source[0]) +\ - (_decode_6bit(source[1])<<6)+\ - (_decode_6bit(source[2])<<12)+\ - (_decode_6bit(source[3])<<18) - except KeyError: - raise ValueError("invalid character") - -def encode_int24(value): - "encodes 24-bit integer -> 4 char hash64 string (little-endian order)" - #NOTE: this is optimized form of encode_int(value,4) - return _encode_6bit(value & 0x3f) + \ - _encode_6bit((value>>6) & 0x3f) + \ - _encode_6bit((value>>12) & 0x3f) + \ - _encode_6bit((value>>18) & 0x3f) - -#--------------------------------------------------------------------- - -def decode_int64(source): - "decodes 11 char hash64 string -> 64-bit integer (little-endian order; 2 msb assumed to be padding)" - return decode_int(source) - -def encode_int64(value): - "encodes 64-bit integer -> 11 char hash64 string (little-endian order; 2 msb of 0's added as padding)" - return encode_int(value, 11) - -def decode_dc_int64(source): - """decode 11 char hash64 string -> 64-bit integer (big-endian order; 2 lsb assumed to be padding) - - this format is used primarily by des-crypt & variants to encode the DES output value - used as a checksum. - """ - return decode_int(source, True)>>2 - -def encode_dc_int64(value): - """encode 64-bit integer -> 11 char hash64 string (big-endian order; 2 lsb added as padding) - - this format is used primarily by des-crypt & variants to encode the DES output value - used as a checksum. - """ - #NOTE: insert 2 padding bits as lsb, to make 66 bits total - return encode_int(value<<2,11,True) - -#--------------------------------------------------------------------- - -def decode_int(source, big=False): - """decode hash64 string -> integer - - :arg source: hash64 string of any length - :arg big: if ``True``, big-endian encoding is used instead of little-endian (the default). - - :raises ValueError: if the string contains invalid hash64 characters. - - :returns: - a integer whose value is in ``range(0,2**(6*len(source)))`` - """ - if not isinstance(source, bytes): - raise TypeError("source must be bytes, not %s" % (type(source),)) - #FORMAT: little-endian, each char contributes 6 bits, - # char value = index in H64_CHARS string - if not big: - source = reversed(source) - try: - out = 0 - for c in source: - #NOTE: under py3, 'c' is int, relying on _CHARIDX to support this. - out = (out<<6) + _decode_6bit(c) - return out - except KeyError: - raise ValueError("invalid character in string") - -def encode_int(value, count, big=False): - """encode integer into hash-64 format - - :arg value: non-negative integer to encode - :arg count: number of output characters / 6 bit chunks to encode - :arg big: if ``True``, big-endian encoding is used instead of little-endian (the default). - - :returns: - a hash64 string of length ``count``. - """ - if value < 0: - raise ValueError("value cannot be negative") - if big: - itr = irange(6*count-6, -6, -6) - else: - itr = irange(0, 6*count, 6) - return bjoin( - _encode_6bit((value>>off) & 0x3f) - for off in itr - ) - -#================================================================================= -#eof -#================================================================================= |