#!/usr/bin/env python3
from pwn import *

HOST = "130.192.5.212"
PORT = "6543"

server = remote(HOST,PORT)
sleepT = 0.1

firstBlock=b"CRYPTO25{e3ab216"
#If the pad generated is correct the second and third block are equal
#Then I guessed the random pad
for i in range(16):
  pad=b'A'*i
  secondBlock=b'B'*16
  thirdBlock=b'B'*16
  server.send(b'enc\n')
  server.recv(1024)
  sleep(sleepT)
  #The second pad can be whatever
  toSend = pad + secondBlock + thirdBlock
  print(f"Sending {toSend} with len {len(toSend)}")
  server.send( toSend.hex())
  server.send(b'\n')
  sleep(sleepT)
  ciphertext = server.recv(1024)
  ciphertext = bytes.fromhex(ciphertext.strip(b" >").split(b"\n")[0].decode('utf-8'))
  if ciphertext[16:32] == ciphertext[32:48]:
      PAD_NUM=i
      print(f"Found the right padding num:{PAD_NUM}")
      break
firstBlock=b"CRYPTO25{e3ab216"
secondBlock="9-39d5-43aa-bde7"
thirdBlock="-02286c2e2e56}"
flag="CRYPTO25{e3ab2169-39d5-43aa-bde7-02286c2e2e56}"
lastBlock=b'A'*16
#lastBlock=firstBlock
flagGuessed=b''
#beginning=32
#end=48
beginning=48
end=64
flag=b''

for j in range(1,3):
    print(f"{'-'*5} Finding block n:{j+1} {'-'*5}")
    for i in range(16):
        beforePad = b'A'*PAD_NUM
        pad = lastBlock[(i+1):]
        #pad =  b'A'*(16 - (len(flagGuessed)+1) )
        fPayload =  pad + flagGuessed
        for guess in string.printable:
            guess = bytes(guess,'utf-8')
            server.send(b'enc\n')
            server.recv(1024)
            sleep(sleepT)
            #The second pad can be whatever
            toSend = beforePad + fPayload+guess+pad
            print(f"Payload len: {len(fPayload+guess)} Pad len: {len(pad)}")
            print(f"Sending {toSend} with len {len(toSend)}")
            server.send( toSend.hex())
            server.send(b'\n')
            sleep(sleepT)
            ciphertext = server.recv(1024)
            ciphertext = bytes.fromhex(ciphertext.strip(b" >").split(b"\n")[0].decode('utf-8'))
            if ciphertext[16:32] == ciphertext[beginning:end]:
                #print(f"Block1:{ciphertext[0:16]} Block2:{ciphertext[16:32]}")
                print(f"Matched guess: {guess}")
                flagGuessed += guess
                print(f"Already Guessed: {flagGuessed}")
                break
            sleep(sleepT)
    lastBlock=flagGuessed
    flag+=lastBlock
    print(f"Entire block guessed:{lastBlock}")
    flagGuessed=b''
    beginning+=16
    end+=16
    if(b'}' in flagGuessed):
        break
print(flag)