hasher.py

#! /usr/bin/python

import hashlib
import sys
import os

class Hasher():
    def __init__(self, filepath, hashtype='sha256', chunksize=64):
        if not hashtype in hashlib.algorithms:
            raise ValueError('hashtype not supported')
        self.hashtype = hashtype

        if not os.path.isfile(filepath):
            raise ValueError('file does not exist')
        self.fp = filepath

        self.chunksize = 64

    def hashFile(self):
        self.hasher = hashlib.new(self.hashtype)
        with open(self.fp, 'rb') as file:
            while 1:
                data = file.read(self.chunksize)
                self.hasher.update(data)
                if len(data) < self.chunksize:
                    break
        return self.hasher.hexdigest()

if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser(description='File hasher')
    parser.add_argument('-f', '--file', help='Path to file', action='store', dest='file', default=False)
    parser.add_argument('--hashtype', help='Hash type to use (must be supported by your hashlib version)', action='store', dest='hashtype', default='sha256')
    parser.add_argument('--chunksize', help='Chunk size', action='store', dest='cs', default='64')
    parser.add_argument('--list-types', help='List supported hash types', action='store_true', dest='list', default=False)
    args = parser.parse_args()
    if (len(sys.argv)==1) or ('--help' in sys.argv or '-h' in sys.argv):
        parser.print_help()
        sys.exit(0)
    else:
        pass
    if not args.file and not args.list:
        parser.error('No filepath given')
    else:
        pass
    try:
        chunksize = int(args.cs)
    except ValueError:
        parser.error('Invalid chunksize given')
    if args.list:
        print '[*] Listing supported hash types... '
        for i in hashlib.algorithms:
            print i.upper()
        sys.exit(0)
    try:
        print '[*] Hashing file... ',;sys.stdout.flush()
        hasher = Hasher(args.file, hashtype=args.hashtype.lower())
        hash = hasher.hashFile()
        print '[DONE]'
        print '[*] %s Hash: %s' %(args.hashtype.upper(), hash)
    except ValueError, e:
        if 'file does not exist' in e:
            parser.error('File does not exist')
        elif 'hashtype not supported' in e:
            parser.error('Hash type not supported')