def edit(self,offset,text):
if offset < 0:
return False
if offset + len(text) > len(self.encdata):
return False
if len(text) == 0:
return False
data = c18.ctrencrypt(self.encdata,self.nounce,self.key)
tmp = data[:offset]+text+data[len(text)+offset:]
self.encdata = c18.ctrencrypt(tmp,self.nounce,self.key)
return True
def __init__(self,data):
self.key = open("/dev/urandom").read(16)
self.nounce = int(open("/dev/urandom").read(8).encode('hex'),16)
self.encdata = c18.ctrencrypt(data,self.nounce,self.key)
SGUgaGFkIGRvbmUgbW9zdCBiaXR0ZXIgd3Jvbmc=\n\
VG8gc29tZSB3aG8gYXJlIG5lYXIgbXkgaGVhcnQs\n\
WWV0IEkgbnVtYmVyIGhpbSBpbiB0aGUgc29uZzs=\n\
SGUsIHRvbywgaGFzIHJlc2lnbmVkIGhpcyBwYXJ0\n\
SW4gdGhlIGNhc3VhbCBjb21lZHk7\n\
SGUsIHRvbywgaGFzIGJlZW4gY2hhbmdlZCBpbiBoaXMgdHVybiw=\n\
VHJhbnNmb3JtZWQgdXR0ZXJseTo=\n\
QSB0ZXJyaWJsZSBiZWF1dHkgaXMgYm9ybi4="
#### encrypting above messages
key = open("/dev/urandom").read(16)
cts = list()
mxlen = 0 # max length of the CT
milen = 999 # min length of the CT
for msg in msgs.split("\n"):
cts.append(c18.ctrencrypt(base64.b64decode(msg),0,key))
l = len(cts[-1])
if l > mxlen:
mxlen = l
if l < milen:
milen = l
#### breaking them
# prepare the key
key = [0]*mxlen
# automated guessing
key = basicautoguessing(cts,key,milen)
key = bigrams(cts,key)
key = trigrams(cts,key)
def myinput(self,s):
s = s.replace(";","\;").replace("=","\=")
prefix = "comment1=cooking%20MCs;userdata="
suffix = ";comment2=%20like%20a%20pound%20of%20bacon"
return c18.ctrencrypt(prefix+s+suffix,self.n,self.k)
