def __init__(self, parent):
""" Create a new ColumnTranspositionCipher instance.
Args:
parent: a class that provides an interafce to CryptographyStudio
"""
super().__init__(parent)
self._key_length = 1
self._cipher = ColumnTranspositionCipher(parent)
self._widget.show_all()
ngram_loader = NGramLoader()
ngram_loader.load("hr.json")
self._bigram_freqs = ngram_loader.get_ngrams(2)
self._update_key_length()
class ColumnTranspositionAnalyzer(WidgetController, CipherAnalyzer):
GLADE_LOCATION = path.dirname(__file__)
TRY_BUTTON_ID = "try_button"
CIPHER_GRID_ID = "cipher_grid"
KEY_ENTRY_ID = "key_entry"
KEY_LENGTH_ENTRY_ID = "key_length_entry"
LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
def __init__(self, parent):
""" Create a new ColumnTranspositionCipher instance.
Args:
parent: a class that provides an interafce to CryptographyStudio
"""
super().__init__(parent)
self._key_length = 1
self._cipher = ColumnTranspositionCipher(parent)
self._widget.show_all()
ngram_loader = NGramLoader()
ngram_loader.load("hr.json")
self._bigram_freqs = ngram_loader.get_ngrams(2)
self._update_key_length()
def _build_gui(self):
""" Build the widget UI of this WidgetController. """
super()._build_gui()
def _load_gui_objects(self):
""" Save references to required objects defined in the .glade file. """
super()._load_gui_objects()
self._try_button = self._builder.get_object(self.TRY_BUTTON_ID)
self._key_length_entry = \
self._builder.get_object(self.KEY_LENGTH_ENTRY_ID)
self._cipher_grid = self._builder.get_object(self.CIPHER_GRID_ID)
self._key_entry = self._builder.get_object(self.KEY_ENTRY_ID)
def _connect_handlers(self):
""" Connect signals with their handler methods. """
super()._connect_handlers()
self._try_button.connect("clicked", self._try_key)
self._key_length_entry.connect("value-changed",
self._update_key_length)
def _create_grid(self):
n = self._key_length
for child in self._cipher_grid.get_children():
child.destroy()
self._grid = [[None] * n for i in range(n)]
for i in range(n):
for j in range(n):
self._grid[i][j] = Gtk.ToggleButton(
str(self._bigram_freq(i, j))[:5])
self._cipher_grid.attach(self._grid[i][j], i, j, 1, 1)
self._grid[i][j].connect("toggled", self._bind_pair, i, j)
self._cipher_grid.show_all()
def _update_key_length(self, *args):
ciphertext = self._parent.get_ciphertext()
ciphertext = ''.join(filter(lambda x: x in self.LETTERS, ciphertext))
self._calculate_key_length(len(ciphertext))
csize = len(ciphertext) // self._key_length
if len(ciphertext) == 0:
self._columns = []
else:
self._columns = [ciphertext[i:i+csize]
for i in range(0, len(ciphertext), csize)]
self._create_grid()
self._blocks = [[i] for i in range(self._key_length)]
self._block_assoc = list(range(self._key_length))
self._update_display()
"""
self._create_key_selectors()
freq = [{} for _ in range(m)]
ttl = [0] * m
filtered = filter(lambda x: x in self.LETTERS, ciphertext.upper())
avg = 0
for i, c in enumerate("".join(filtered)):
ttl[i % m] += 1
if c in freq[i % m]:
freq[i % m][c] += 1
else:
freq[i % m][c] = 1
for i, cs in enumerate(self._cis):
ci = 0;
for value in freq[i].values():
ci += value * (value - 1)
if ttl[i] > 1:
ci /= ttl[i] * (ttl[i] - 1)
else:
ci = 0
avg += ci
cs.set_text(str(ci)[:5])
self._cindex_field.set_text(str(avg/m)[:5])
"""
def _calculate_key_length(self, ctext_length):
nl = int(self._key_length_entry.get_text())
if nl > ctext_length:
nl = ctext_length if ctext_length else 1
while ctext_length % nl != 0:
nl += 1 if self._key_length < nl else -1
self._key_length = nl
self._key_length_entry.set_text(str(nl))
def _bigram_freq(self, i, j):
return sum(self._bigram_freqs.get(f + s, 0)
for f, s in zip(self._columns[i], self._columns[j]))
def _bind_pair(self, button, fst, scnd, *args):
pass
def _update_display(self):
self._key_entry.set_text(
' '.join(map(lambda x: str(x+1), sum(self._blocks, []))))
self._parent.set_plaintext('\n'.join(
''.join(a) for a in zip(*self._columns)))
def _try_key(self, *args):
""" A handler method that trys to decrypt the text in the parents
ciphertext view.
Args:
*args: arguments passed from the signal
"""
key = self._get_key()
ciphertext = self._parent.get_ciphertext()
self._parent.set_plaintext(self._cipher.decrypt(ciphertext, key))
