def _get_candidate_block_from(self, block):
integer = BytesToInt(block).value()
root = NthRoot(self.e).value(integer)
next_power = (root + 1)**self.e
candidate_block = self._to_bytes(next_power)
return root + 1, LeftPadder(candidate_block).value(self.n_size,
char='\x00')
def _decode(self, string):
bin_string = str()
string = string.strip()
for char in string:
if char == '=':
break
index = self._index_of(char)
if index is None:
continue
bin_index = IntToBinary(index).value()
padded_bin_index = LeftPadder(bin_index).value(6)
bin_string += padded_bin_index
bin_string = self._remove_base64_padding(string, bin_string)
return bin_string
def value(self, size=None):
hex_string = IntToHex(self.integer).value()
int_bytes = HexToBytes(hex_string).value()
if size is not None and len(int_bytes) < size:
int_bytes = LeftPadder(int_bytes).value(size, char='\0')
return int_bytes
def _ensure_length_multiple_of(string, value):
length = len(string)
if length % value != 0:
pad_size = int(value*math.ceil(length/float(value)))
string = LeftPadder(string).value(pad_size)
return string
def _to_bin(self, char):
bin_string = bin(ord(char))[2:]
return LeftPadder(bin_string).value(8)
def _decrypt(self, signature):
decrypted_block = self.rsa.encrypt(signature)
return LeftPadder(decrypted_block).value(self.n_size, char='\0')
def has_valid_padding(self, ciphertext):
plaintext = self.rsa.decrypt(ciphertext)
plaintext = LeftPadder(plaintext).value(self.n_size, char='\0')
return plaintext[0] == '\x00' and plaintext[1] == '\x02'
def _from_int(self, integer):
converter = self._from_int_converter()
string = converter(integer).value()
length = max(map(len, self.strings))
pad_char = self._pad_char()
return LeftPadder(string).value(length, char=pad_char)