Fletcher_checksum

Implementation of fletcher-16, fletcher-32, and fletcher-64 checksums in Python3 for working with string and bytes data.

Description

The Fletcher checksum is an algorithm for computing a position-dependent checksum devised by John G. Fletcher (1934–2012) at Lawrence Livermore Labs in the late 1970s. The objective of the Fletcher checksum was to provide error-detection properties approaching those of a cyclic redundancy check but with the lower computational effort associated with summation techniques.

API

This library has functions for working with string and byte data (which also allows you to calculate the checksum for your files). An example of usage is shown below.

# Importing classes with static methods for working with strings and bytes
from FletcherChecksumLib import FletcherChecksumStr, FletcherChecksumBytes

# Example of using string input
test_string_input = 'Hello, world!'
checksum_result = FletcherChecksumStr.get_fletcher16(test_string_input)
print(checksum_result)

>>>   { 
>>>     'Fletcher16_dec': 29069,
>>>     'Fletcher16_hex': '0x718d' 
>>>   }

# Example of using bytes input
test_bytes_input = b'\xd0\x91\xd0\xb0\xd0\xb9\xd1\x82\xd1\x8b'
checksum_result = FletcherChecksumBytes.get_fletcher32(test_bytes_input)
print(checksum_result)

>>>   { 
>>>     'Fletcher32_dec': 670893849,
>>>     'Fletcher32_hex': '0x27fd0719'
>>>   }

# Example of using file(bytes) input
test_file_input = open('test.txt', 'rb')
test_bytes_input = test_file_input.read()
checksum_result = FletcherChecksumBytes.get_fletcher64(test_bytes_input)
print(checksum_result)

>>>   { 
>>>     'Fletcher64_dec': 35532264440969,
>>>     'Fletcher64_hex': '0x205100000489'
>>>   }