Sha256: 7558403af9fc3164553fe6042a4344ecc42444d0590365c6c76050ca980924ea
Contents?: true
Size: 1.31 KB
Versions: 3
Compression:
Stored size: 1.31 KB
Contents
# encoding: ascii-8bit
# Copyright 2023 OpenC3, Inc.
# All Rights Reserved.
#
# Licensed for Evaluation and Educational Use
#
# This file may only be used commercially under the terms of a commercial license
# purchased from OpenC3, Inc.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# The development of this software was funded in-whole or in-part by MethaneSAT LLC.
class CfdpChecksum
def initialize
@checksum = 0
end
def add(offset, data)
front_pad_bytes = offset % 4
if front_pad_bytes != 0
data = ("\x00" * front_pad_bytes) << data
end
end_pad_bytes = 4 - data.length % 4
if end_pad_bytes != 4
data = data + ("\x00" * end_pad_bytes)
end
values = data.unpack('N*')
values.each do |value|
@checksum += value
end
return @checksum
end
# Expected to be calculated as we go using add, so file unused
def checksum(file, full_checksum_needed)
if full_checksum_needed
file.rewind
data = file.read
@checksum = 0
add(0, data)
end
return @checksum & 0xFFFFFFFF
end
def check(file, other_checksum, full_checksum_needed)
checksum(file, full_checksum_needed) == other_checksum
end
end
Version data entries
3 entries across 3 versions & 1 rubygems