diff options
Diffstat (limited to 'gr-digital/python/digital/crc.py')
| -rw-r--r-- | gr-digital/python/digital/crc.py | 31 |
1 files changed, 19 insertions, 12 deletions
diff --git a/gr-digital/python/digital/crc.py b/gr-digital/python/digital/crc.py index 0b48da69a6..2cec0d446e 100644 --- a/gr-digital/python/digital/crc.py +++ b/gr-digital/python/digital/crc.py @@ -5,21 +5,28 @@ # # SPDX-License-Identifier: GPL-3.0-or-later # -# +""" +Backward-compatible wrapper for CRC32 +""" -from . import digital_python as digital +import zlib import struct -def gen_and_append_crc32(s): - crc = digital.crc32(s) - return s + struct.pack(">I", crc) +def gen_and_append_crc32(data): + """ + Return a binary string with its CRC appended + """ + return data + struct.pack(">I", zlib.crc32(data)) + +def check_crc32(data): + """ + Check if the byte string 's' has a valid CRC on its last four bytes -def check_crc32(s): - if len(s) < 4: + Returns a tuple (is CRC valid, string-without-CRC). + """ + if len(data) < 4: return (False, '') - msg = s[:-4] - #print "msg = '%s'" % (msg,) - actual = digital.crc32(msg) - (expected,) = struct.unpack(">I", s[-4:]) - # print "actual =", hex(actual), "expected =", hex(expected) + msg = data[:-4] # Message without the CRC + actual = zlib.crc32(msg) + (expected,) = struct.unpack(">I", data[-4:]) return (actual == expected, msg) |