In [4]:

    

import sys
sys.path.insert(0, '../')

from blockcrypto import *
globalkey=randomkey(16)


    

In [27]:

    

import random
rcount=random.randint(1,64)
rprefix=randomkey(rcount)


    

In [28]:

    

def myoracle(key,attack):
    global rprefix
    return encryptECBAES(key,pad(rprefix+attack+"decryptme",16))


    

In [29]:

    

print newECBorCBCoracle(globalkey,16,myoracle)


    

    




ECB

In [30]:

    

import numpy as np

def wherearewe(blackbox, key):
    #return offset to block
    pastblocks=np.zeros(16)
    blocksnoinput = splitblocks(blackbox(key,""), 16)
    blocksonebyte=splitblocks(blackbox(key,"A"), 16)
    #numsameorig=np.sum(np.array(blocksnoinput)==np.array(blocksonebyte))
    numsameorig=len(set(blocksnoinput).intersection(set(blocksonebyte)))
    for b in xrange(1,18):
        blocks = splitblocks(blackbox(key,"A"*b), 16)
        #numsame=np.sum(np.array(blocksnoinput)==np.array(blocks))
        numsame=len(set(blocks).intersection(set(pastblocks)))
        if numsame>numsameorig:
            return ((b-1)%16, np.max(np.where(np.array(blocks[:len(pastblocks)])==np.array(pastblocks)) ))
        pastblocks=blocks
    return None

(offset,ourblock) =wherearewe(myoracle,globalkey) #expect 10
print offset, ourblock
lengthprefix = (ourblock)*16 + (16-offset)
###So we want to start with 35As, then reduce

### TODO - We need to set the starting block correctly - want to extract from second block not first to begin with

#print len(rprefix)
print lengthprefix


    

    




8 1
24
24

In [40]:

    

print unpad(newpadoracle(myoracle, 16,len(myoracle(globalkey,"")), globalkey, offset=offset, ourblock=ourblock ))


    

    




decryptme

In [39]:

    

def newcreatedict(blackbox, key,blocksize,curblock=0,byte=1,knownletters=[], offset=0):
    d={}
    z=(curblock*blocksize)
    #print z, z+blocksize, byte
    #print ascii2hex(blackbox(key,("A"*((blocksize-1)+offset))+"&"))
    #print ':'.join(x.encode('hex') for x in blackbox(key,("A"*((blocksize-2)+offset))+"=u")[16:32])
    for a in xrange(0,128):
        #print ("A"*((blocksize-byte)))+"".join(knownletters)+chr(a)
        d[blackbox(key,("A"*((blocksize-byte)+offset))+"".join(knownletters)+chr(a))[z:z+blocksize]]=chr(a)
    #print ("A"*((blocksize-byte)))+"".join(knownletters)+chr(a)
    return d

# TODO CANNOT GET FIRST BYTE ?!?

def newpadoracle(blackbox,blocksize,totalbytes,key, offset=0, ourblock=0):
    outs=[]
    knownletters=[]
    for b in xrange((ourblock+1),(totalbytes/blocksize)+1):
        o=""
        for byte in xrange(1,blocksize+1):
            #print b,byte,offset,blocksize,((blocksize-byte)+offset)
            #print b*blocksize, (b+1)*blocksize
            #print blackbox(key, "A"*((blocksize-1)+offset))
            #print ':'.join(x.encode('hex') for x in blackbox(key, "A"*((blocksize-2)+offset)+"=")[16:32])

            onebyteshort=blackbox(key, "A"*((blocksize-byte)+offset))
            d=newcreatedict(blackbox,key,blocksize,curblock=b,byte=byte,knownletters=knownletters, offset=offset)
            #print d
            #print d
            try: #TODO: Hack for last byte
                knownletters.append(d[onebyteshort[b*blocksize:(b+1)*blocksize]])
                o+=d[onebyteshort[b*blocksize:(b+1)*blocksize]]
                #print o
            except Exception as e:
                #print e
                pass
           # print o, b
        outs.append(o)
       #print outs,b
    return "".join(outs)


    

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