def encrypt_cbc(data, iv, key):
enc_data = []
keylen = len(key)
xor_with = binascii.hexlify(iv)
for block in [data[i:i + keylen] for i in range(0, len(data), keylen)]:
xored = hex_xor(binascii.hexlify(block), xor_with)
enc_aes = aes_ecb_encrypt(binascii.unhexlify(xored), key)
enc_data.append(''.join(enc_aes))
xor_with = binascii.hexlify(enc_aes)
return ''.join(enc_data)
#repeats=0
for chunk in [
data[i + offset:i + offset + chunksize]
for i in range(0, len(data), chunksize)
]:
if chunk in chunks:
return True #if duplicate chunk found then ECB
else:
chunks.add(chunk)
#all_repeats.append(repeats)
return False #(max(all_repeats)>0) #CBC
if __name__ == '__main__':
key = random_key(16)
iv = random_key(16)
mode = random.randint(0, 1)
pre_buffer = random_key(random.randrange(5))
post_buffer = random_key(random.randrange(5))
script_dir = os.path.dirname(__file__)
fo = open(os.path.join(script_dir, "asciidata.txt"), "r")
raw_data = fo.read()
fo.close()
rand_data = pkcs7_key(str(pre_buffer) + raw_data + str(post_buffer), key)
if mode: #1
enc_data = aes_ecb_encrypt(rand_data, key)
else: #0
enc_data = encrypt_cbc(rand_data, iv, key)
print(key, mode, oracle(enc_data))
def make_enc_str(s1,s2,key):
return(aes_ecb_encrypt(pkcs7_key(s1+s2,key),key))
def decrypt_ecb(str,key):
keylen=len(key)
hashes=make_hashes(keylen,key)
indexes=[hashes.index(aes_ecb_encrypt("a"*(keylen-1)+x,key)) for x in str]
return ''.join([chr(x) for x in indexes])
def make_hashes(keylen,key):
return [aes_ecb_encrypt("a"*(keylen-1)+chr(x),key) for x in range(256)]