AES Decryption throws ValueError: Input strings must be a multiple of 16 in length
AES Decryption throws ValueError: Input strings must be a multiple of 16 in length
我得到了 Github(@Cahlen Humphreys) 的当前代码，最初它无法正常工作，但经过微小的更改后它可以运行以进行加密，
but decryption gives me the following error:
return self.func(*args)
File "C:/Users/W4RL0RD/Desktop/websec.py", line 183, in cipher_open
decrypt(filename,password)
File "C:/Users/W4RL0RD/Desktop/websec.py", line 117, in decrypt
decrypted = obj2.decrypt(ciphertext)
File "C:\Users\W4RL0RD\Anaconda2\lib\site-packages\Crypto\Cipher\blockalgo.py", line 295, in decrypt
return self._cipher.decrypt(ciphertext)
ValueError: Input strings must be a multiple of 16 in length
from Tkinter import *
from tkFileDialog import *
import tkMessageBox
import os
import PIL
import math
from Crypto.Cipher import AES
import hashlib
import binascii
global password
# encryption method
# -----------------
def encrypt(imagename,password):
# initialize variables
plaintext = list()
plaintextstr = ""
# load the image
im = PIL.Image.open(imagename) # open target image
pix = im.load()
#print im.size # print size of image (width,height)
width = im.size[0]
height = im.size[1]
# break up the image into a list, each with pixel values and then append to a string
for y in range(0,height):
#print("Row: %d") %y # print row number
for x in range(0,width):
#print pix[x,y] # print each pixel RGB tuple
plaintext.append(pix[x,y])
# add 100 to each tuple value to make sure each are 3 digits long. being able to do this is really just a PoC
# that you'll be able to use a raw application of RSA to encrypt, rather than PyCrypto if you wanted.
for i in range(0,len(plaintext)):
for j in range(0,3):
plaintextstr = plaintextstr + "%d" %(int(plaintext[i][j])+100)
# length save for encrypted image reconstruction
relength = len(plaintext)
# append dimensions of image for reconstruction after decryption
plaintextstr += "h" + str(height) + "h" + "w" + str(width) + "w"
# make sure that plantextstr length is a multiple of 16 for AES. if not, append "n". not safe in theory
# and i should probably replace this with an initialization vector IV = 16 * '\x00' at some point. In practice
# this IV buffer should be random.
while (len(plaintextstr) % 16 != 0):
plaintextstr = plaintextstr + "n"
# encrypt plaintext
obj = AES.new(password, AES.MODE_CBC, 'This is an IV456')
ciphertext = obj.encrypt(plaintextstr)
# write ciphertext to file for analysis
cipher_name = imagename + ".crypt"
g = open(cipher_name, 'w')
g.write(ciphertext)
# -----------------
# construct encrypted image (not currently using since Tkinter isn't very nice)
# -----------------
def construct_enc_image():
# hexlify the ciphertext
asciicipher = binascii.hexlify(ciphertext)
# replace function
def replace_all(text, dic):
for i, j in dic.iteritems():
text = text.replace(i, j)
return text
# use replace function to replace ascii cipher characters with numbers
reps = {'a':'1', 'b':'2', 'c':'3', 'd':'4', 'e':'5', 'f':'6', 'g':'7', 'h':'8', 'i':'9', 'j':'10', 'k':'11', 'l':'12', 'm':'13', 'n':'14', 'o':'15', 'p':'16', 'q':'17', 'r':'18', 's':'19', 't':'20', 'u':'21', 'v':'22', 'w':'23', 'x':'24', 'y':'25', 'z':'26'}
asciiciphertxt = replace_all(asciicipher, reps)
# construct encrypted image
step = 3
encimageone=[asciiciphertxt[i:i+step] for i in range(0, len(asciiciphertxt), step)]
# if the last pixel RGB value is less than 3-digits, add a digit a 1
if int(encimageone[len(encimageone)-1]) < 100:
encimageone[len(encimageone)-1] += "1"
# check to see if we can divide the string into partitions of 3 digits. if not, fill in with some garbage RGB values
if len(encimageone) % 3 != 0:
while (len(encimageone) % 3 != 0):
encimageone.append("101")
encimagetwo=[(int(encimageone[int(i)]),int(encimageone[int(i+1)]),int(encimageone[int(i+2)])) for i in range(0, len(encimageone), step)]
# make sizes of images equal
while (int(relength) != len(encimagetwo)):
encimagetwo.pop()
# encrypted image
encim = PIL.Image.new("RGB", (int(width),int(height)))
encim.putdata(encimagetwo)
#encim.show()
# alert success and path to image
enc_success(cipher_name)
construct_enc_image()
# decryption method
# -----------------
def decrypt(ciphername,password):
# reach ciphertext into memory
cipher = open(ciphername,'r')
ciphertext = cipher.read()
# decrypt ciphertext with password
obj2 = AES.new(password, AES.MODE_CBC, 'This is an IV456')
decrypted = obj2.decrypt(ciphertext)
# parse the decrypted text back into integer string
decrypted = decrypted.replace("n","")
# extract dimensions of images
newwidth = decrypted.split("w")[1]
newheight = decrypted.split("h")[1]
# replace height and width with emptyspace in decrypted plaintext
heightr = "h" + str(newheight) + "h"
widthr = "w" + str(newwidth) + "w"
decrypted = decrypted.replace(heightr,"")
decrypted = decrypted.replace(widthr,"")
# reconstruct the list of RGB tuples from the decrypted plaintext
step = 3
finaltextone=[decrypted[i:i+step] for i in range(0, len(decrypted), step)]
finaltexttwo=[(int(finaltextone[int(i)])-100,int(finaltextone[int(i+1)])-100,int(finaltextone[int(i+2)])-100) for i in range(0, len(finaltextone), step)]
# reconstruct image from list of pixel RGB tuples
newim = Image.new("RGB", (int(newwidth), int(newheight)))
newim.putdata(finaltexttwo)
newim.show()
# ---------------------
# GUI stuff starts here
# ---------------------
# empty password alert
def pass_alert():
tkMessageBox.showinfo("Password Alert","Please enter a password.")
def enc_success(imagename):
tkMessageBox.showinfo("Success","Encrypted Image: " + imagename)
# image encrypt button event
def image_open():
# useless for now, may need later
global file_path_e
# check to see if password entry is null. if yes, alert
enc_pass = passg.get()
if enc_pass == "":
pass_alert()
else:
password = hashlib.sha256(enc_pass).digest()
filename = askopenfilename()
file_path_e = os.path.dirname(filename)
# encrypt the image
encrypt(filename,password)
# image decrypt button event
def cipher_open():
# useless for now, may need later
global file_path_d
# check to see if password entry is null. if yes, alert
dec_pass = passg.get()
if dec_pass == "":
pass_alert()
else:
password = hashlib.sha256(dec_pass).digest()
filename = askopenfilename()
file_path_d = os.path.dirname(filename)
# decrypt the ciphertext
decrypt(filename,password)
# main gui app starts here
class App:
def __init__(self, master):
# make passg global to use in functions
global passg
# setup frontend titles etc blah blah
title = "Image Encryption"
author = "Kumod Arya\n16BCI0172"
msgtitle = Message(master, text =title)
msgtitle.config(font=('helvetica', 17, 'bold'), width=200)
msgauthor = Message(master, text=author)
msgauthor.config(font=('helvetica',10), width=200)
# draw canvas
canvas_width = 200
canvas_height = 50
w = Canvas(master,
width=canvas_width,
height=canvas_height)
# pack the GUI, this is basic, we shold use a grid system
msgtitle.pack()
msgauthor.pack()
w.pack()
# password field here above buttons
passlabel = Label(master, text="Enter Encrypt/Decrypt Password:")
passlabel.pack()
passg = Entry(master, show="*", width=20)
passg.pack()
# add both encrypt/decrypt buttons here which trigger file browsers
self.encrypt = Button(master,
text="Encrypt", fg="black",
command=image_open, width=25,height=5)
self.encrypt.pack(side=LEFT)
self.decrypt = Button(master,
text="Decrypt", fg="black",
command=cipher_open, width=25,height=5)
self.decrypt.pack(side=RIGHT)
root = Tk()
root.wm_title("Image Encryption")
app = App(root)
root.mainloop()
您的代码存在一些安全问题：
- 直接使用填充的明文密码作为加密密钥是不安全的。请改用 scrypt 或 PBKDF2 等密钥派生函数。
- 固定的 IV 基本上没有用。使用随机字节作为 IV 与密文一起存储。
- 最好使用 MAC（例如 HMAC 或 GCM）来验证解密数据。
话虽如此，我猜测它不起作用的原因是您在 Windows 上 运行 或使用非拉丁语默认字符集。
尝试将二进制模式添加到 open() 个调用：
open(cipher_name, 'w')→open(cipher_name, 'wb')
open(ciphername,'r')→open(ciphername,'rb')
我得到了 Github(@Cahlen Humphreys) 的当前代码，最初它无法正常工作，但经过微小的更改后它可以运行以进行加密，
but decryption gives me the following error:
return self.func(*args) File "C:/Users/W4RL0RD/Desktop/websec.py", line 183, in cipher_open decrypt(filename,password) File "C:/Users/W4RL0RD/Desktop/websec.py", line 117, in decrypt decrypted = obj2.decrypt(ciphertext) File "C:\Users\W4RL0RD\Anaconda2\lib\site-packages\Crypto\Cipher\blockalgo.py", line 295, in decrypt return self._cipher.decrypt(ciphertext) ValueError: Input strings must be a multiple of 16 in length
from Tkinter import *
from tkFileDialog import *
import tkMessageBox
import os
import PIL
import math
from Crypto.Cipher import AES
import hashlib
import binascii
global password
# encryption method
# -----------------
def encrypt(imagename,password):
# initialize variables
plaintext = list()
plaintextstr = ""
# load the image
im = PIL.Image.open(imagename) # open target image
pix = im.load()
#print im.size # print size of image (width,height)
width = im.size[0]
height = im.size[1]
# break up the image into a list, each with pixel values and then append to a string
for y in range(0,height):
#print("Row: %d") %y # print row number
for x in range(0,width):
#print pix[x,y] # print each pixel RGB tuple
plaintext.append(pix[x,y])
# add 100 to each tuple value to make sure each are 3 digits long. being able to do this is really just a PoC
# that you'll be able to use a raw application of RSA to encrypt, rather than PyCrypto if you wanted.
for i in range(0,len(plaintext)):
for j in range(0,3):
plaintextstr = plaintextstr + "%d" %(int(plaintext[i][j])+100)
# length save for encrypted image reconstruction
relength = len(plaintext)
# append dimensions of image for reconstruction after decryption
plaintextstr += "h" + str(height) + "h" + "w" + str(width) + "w"
# make sure that plantextstr length is a multiple of 16 for AES. if not, append "n". not safe in theory
# and i should probably replace this with an initialization vector IV = 16 * '\x00' at some point. In practice
# this IV buffer should be random.
while (len(plaintextstr) % 16 != 0):
plaintextstr = plaintextstr + "n"
# encrypt plaintext
obj = AES.new(password, AES.MODE_CBC, 'This is an IV456')
ciphertext = obj.encrypt(plaintextstr)
# write ciphertext to file for analysis
cipher_name = imagename + ".crypt"
g = open(cipher_name, 'w')
g.write(ciphertext)
# -----------------
# construct encrypted image (not currently using since Tkinter isn't very nice)
# -----------------
def construct_enc_image():
# hexlify the ciphertext
asciicipher = binascii.hexlify(ciphertext)
# replace function
def replace_all(text, dic):
for i, j in dic.iteritems():
text = text.replace(i, j)
return text
# use replace function to replace ascii cipher characters with numbers
reps = {'a':'1', 'b':'2', 'c':'3', 'd':'4', 'e':'5', 'f':'6', 'g':'7', 'h':'8', 'i':'9', 'j':'10', 'k':'11', 'l':'12', 'm':'13', 'n':'14', 'o':'15', 'p':'16', 'q':'17', 'r':'18', 's':'19', 't':'20', 'u':'21', 'v':'22', 'w':'23', 'x':'24', 'y':'25', 'z':'26'}
asciiciphertxt = replace_all(asciicipher, reps)
# construct encrypted image
step = 3
encimageone=[asciiciphertxt[i:i+step] for i in range(0, len(asciiciphertxt), step)]
# if the last pixel RGB value is less than 3-digits, add a digit a 1
if int(encimageone[len(encimageone)-1]) < 100:
encimageone[len(encimageone)-1] += "1"
# check to see if we can divide the string into partitions of 3 digits. if not, fill in with some garbage RGB values
if len(encimageone) % 3 != 0:
while (len(encimageone) % 3 != 0):
encimageone.append("101")
encimagetwo=[(int(encimageone[int(i)]),int(encimageone[int(i+1)]),int(encimageone[int(i+2)])) for i in range(0, len(encimageone), step)]
# make sizes of images equal
while (int(relength) != len(encimagetwo)):
encimagetwo.pop()
# encrypted image
encim = PIL.Image.new("RGB", (int(width),int(height)))
encim.putdata(encimagetwo)
#encim.show()
# alert success and path to image
enc_success(cipher_name)
construct_enc_image()
# decryption method
# -----------------
def decrypt(ciphername,password):
# reach ciphertext into memory
cipher = open(ciphername,'r')
ciphertext = cipher.read()
# decrypt ciphertext with password
obj2 = AES.new(password, AES.MODE_CBC, 'This is an IV456')
decrypted = obj2.decrypt(ciphertext)
# parse the decrypted text back into integer string
decrypted = decrypted.replace("n","")
# extract dimensions of images
newwidth = decrypted.split("w")[1]
newheight = decrypted.split("h")[1]
# replace height and width with emptyspace in decrypted plaintext
heightr = "h" + str(newheight) + "h"
widthr = "w" + str(newwidth) + "w"
decrypted = decrypted.replace(heightr,"")
decrypted = decrypted.replace(widthr,"")
# reconstruct the list of RGB tuples from the decrypted plaintext
step = 3
finaltextone=[decrypted[i:i+step] for i in range(0, len(decrypted), step)]
finaltexttwo=[(int(finaltextone[int(i)])-100,int(finaltextone[int(i+1)])-100,int(finaltextone[int(i+2)])-100) for i in range(0, len(finaltextone), step)]
# reconstruct image from list of pixel RGB tuples
newim = Image.new("RGB", (int(newwidth), int(newheight)))
newim.putdata(finaltexttwo)
newim.show()
# ---------------------
# GUI stuff starts here
# ---------------------
# empty password alert
def pass_alert():
tkMessageBox.showinfo("Password Alert","Please enter a password.")
def enc_success(imagename):
tkMessageBox.showinfo("Success","Encrypted Image: " + imagename)
# image encrypt button event
def image_open():
# useless for now, may need later
global file_path_e
# check to see if password entry is null. if yes, alert
enc_pass = passg.get()
if enc_pass == "":
pass_alert()
else:
password = hashlib.sha256(enc_pass).digest()
filename = askopenfilename()
file_path_e = os.path.dirname(filename)
# encrypt the image
encrypt(filename,password)
# image decrypt button event
def cipher_open():
# useless for now, may need later
global file_path_d
# check to see if password entry is null. if yes, alert
dec_pass = passg.get()
if dec_pass == "":
pass_alert()
else:
password = hashlib.sha256(dec_pass).digest()
filename = askopenfilename()
file_path_d = os.path.dirname(filename)
# decrypt the ciphertext
decrypt(filename,password)
# main gui app starts here
class App:
def __init__(self, master):
# make passg global to use in functions
global passg
# setup frontend titles etc blah blah
title = "Image Encryption"
author = "Kumod Arya\n16BCI0172"
msgtitle = Message(master, text =title)
msgtitle.config(font=('helvetica', 17, 'bold'), width=200)
msgauthor = Message(master, text=author)
msgauthor.config(font=('helvetica',10), width=200)
# draw canvas
canvas_width = 200
canvas_height = 50
w = Canvas(master,
width=canvas_width,
height=canvas_height)
# pack the GUI, this is basic, we shold use a grid system
msgtitle.pack()
msgauthor.pack()
w.pack()
# password field here above buttons
passlabel = Label(master, text="Enter Encrypt/Decrypt Password:")
passlabel.pack()
passg = Entry(master, show="*", width=20)
passg.pack()
# add both encrypt/decrypt buttons here which trigger file browsers
self.encrypt = Button(master,
text="Encrypt", fg="black",
command=image_open, width=25,height=5)
self.encrypt.pack(side=LEFT)
self.decrypt = Button(master,
text="Decrypt", fg="black",
command=cipher_open, width=25,height=5)
self.decrypt.pack(side=RIGHT)
root = Tk()
root.wm_title("Image Encryption")
app = App(root)
root.mainloop()
您的代码存在一些安全问题：
- 直接使用填充的明文密码作为加密密钥是不安全的。请改用 scrypt 或 PBKDF2 等密钥派生函数。
- 固定的 IV 基本上没有用。使用随机字节作为 IV 与密文一起存储。
- 最好使用 MAC（例如 HMAC 或 GCM）来验证解密数据。
话虽如此，我猜测它不起作用的原因是您在 Windows 上 运行 或使用非拉丁语默认字符集。
尝试将二进制模式添加到 open() 个调用：
open(cipher_name, 'w')→open(cipher_name, 'wb')open(ciphername,'r')→open(ciphername,'rb')