How to do md5 checksum verification on files after download from ftp server using pysftp

Question

I am new to pysftp I am trying to do the following task

1. Connect to ftp server and download the files
2. Generate md5 checksum on files and making sure they are not tampered with

Can someone help me with this script?

I tried connecting to the server but I am unsure how to go about downloading the files and generating a checksum for the files on the downloaded files using python.

As of now I have connected to the server with the below code: *

import pysftp
cnopts = pysftp.CnOpts()
cnopts.hostkeys = None   
myHostname = "abc.org"
myUsername = "username"
myPassword = "password"

with pysftp.Connection(host=myHostname, username=myUsername, password=myPassword, cnopts=cnopts) as sftp:
    print ("Connection succesfully stablished ... ")
    directory_structure = sftp.listdir_attr()
    for attr in directory_structure:
        print (attr.filename, attr)

**

Answer 1

The psftp get() method is documented here.

The python hashlib module is documented here. It provides many hash algorithms including MD5 and SHA256.

Example :

import hashlib

content = "header\foobar\nfooter\n"  # your file content as a string
h = hashlib.sha256(content.encode())

tampered_content = "header\foobar2\nfooter\n"  # your file content (modified) as a string
h2 = hashlib.sha256(tampered_content.encode())

h.digest() == h2.digest()  # False

print(h.hexdigest())  # an hexadecimal human-readable string to provide on the server

# 17f1212df75eac78cd7c01c19ea44823add3f778ebe39b22cb5d7415c94c8395