Examples for tutorial on symmetric ciphers available under https://mareknarozniak.com/2021/04/22/symmetric/

aes.py

from Crypto.Cipher import AES
from getpass import getpass

ciphertext = None
with open('ciphertext3.txt', 'r') as file:
    ciphertext = bytes.fromhex(file.read())

password = getpass('Password: ')
key = bytes(password, 'ascii')
key = key + b'\x00'*(16-len(key))

vect = getpass('IV: ')
IV = bytes.fromhex(vect)

cipher = AES.new(key, AES.MODE_CBC, IV=IV)
plaintext = cipher.decrypt(ciphertext)

print(plaintext)

caesar.py

def rotate(alphabet, rot):
    return alphabet[rot:] + alphabet[:rot]


def applyCipher(alphabet, cipher):
    unique = str(''.join(list(dict.fromkeys(list(cipher)))))
    applied = str(alphabet)
    for c in unique:
        applied = applied.replace(c, '')
    applied = unique + applied
    return applied


def encrypt(plaintext, alphabet, cipher, rot):
    lookup = rotate(applyCipher(alphabet, cipher), rot)
    ciphertext = ''
    for c in plaintext:
        index = alphabet.index(c)
        cp = lookup[index]
        ciphertext += cp
    return ciphertext


def decrypt(ciphertext, alphabet, cipher, rot):
    lookup = rotate(applyCipher(alphabet, cipher), rot)
    plaintext = ''
    for c in ciphertext:
        index = lookup.index(c)
        cp = alphabet[index]
        plaintext += cp
    return plaintext

poke = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz\'?!.,0123456789 '

for i in [1, 2]:
    filename = 'plaintext{0}.txt'.format(str(i))

    data = None
    with open(filename, 'r') as file:
        data = file.read().split('\n')

    plaintext = data[0]
    cipher = data[1]
    rot = int(data[2])

    ciphertext = encrypt(plaintext, poke, cipher, rot)
    decrypted = decrypt(ciphertext, poke, cipher, rot)

    assert plaintext == decrypted

    outfile = 'ciphertext{0}.txt'.format(str(i))
    with open(outfile, 'w') as file:
        file.write(ciphertext)

ciphertext1.txt

Iurt0rh0hz6rmugmzwvzhg5rIurgmzk?mzhzruvrvuhrouv.z5rHmghzr'lhrjbfh6rqmhzr'lhrzuboh5rIur'lhrz?urmurt0rgmzkybfh5rBvmqmukrlhb'6rz?tthyrz'hufl5r2Nhb'lr'lhrcqbfor'lhrzo0rqvvozrghbg5rCbqqrt0rubthr'lyv?klr'lhrfyhbt5rAugrI2qqrlhbyr0v?rzfyhbtrbkbmu5rBqbforlvqhrz?u6r.vu2'r0v?rfvthrbugr.bzlrb.b0r'lhrybmu3rBqbforlvqhrz?u6r.vu2'r0v?rfvth3rWvu2'r0v?rfvth3rWvu2'r0v?rfvth3

ciphertext2.txt

Et'X,tgczt'j??juftjut?gctzXju8tOXjubzvw'teXppjuftvutgcz8tPgctbjbu5?t'ccqt?vtZXzc8tPgct'X?t?gczctXubt'qjpcbtX?tqcmubtEtnuc,t'gctZv!pbtqXnctqctgXww28tApv,cz'tjutgcztgXjz tepv,cz'tc.cz2,gczc7tEtpv.ct?gctepv,cztfjzp8tKg tEtbvu5?tnuv,tk!'?t,g2t'gct'jqwp2tZX!fg?tq2tc2c8tEtpv.ct?gctepv,cztfjzpt'gct'ccqcbt'vt',cc?tXubtnjub8tPgctZzcw?tju?vtq2tqjub8

ciphertext3.txt

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

plaintext1.txt

In my eyes, indisposed. In disguises no one knows. Hides the face, lies the snake. In the sun in my disgrace. Boiling heat, summer stench. 'Neath the black the sky looks dead. Call my name through the cream. And I'll hear you scream again. Black hole sun, won't you come and wash away the rain? Black hole sun, won't you come? Won't you come? Won't you come?
disappear
7

plaintext2.txt

here put text
<here password>
0

requirements.txt

pycryptodome