Cryptography With Python 简明教程

Decryption of files

在本章中，让我们讨论使用 Python 对密码学中的文件进行解密。请注意，对于解密过程，我们将遵循相同的过程，但不是指定输出路径，而是关注输入路径或加密的必要文件。

In this chapter, let us discuss decryption of files in cryptography using Python. Note that for decryption process, we will follow the same procedure, but instead of specifying the output path, we will focus on input path or the necessary file which is encrypted.

Code

以下是使用 Python 对密码学中的文件进行解密的示例代码：

The following is a sample code for decrypting files in cryptography using Python −

#!/usr/bin/python
# ---------------- READ ME ---------------------------------------------
# This Script is Created Only For Practise And Educational Purpose Only
# This Script Is Created For http://bitforestinfo.blogspot.in
# This Script is Written By
#
#
##################################################
######## Please Don't Remove Author Name #########
############### Thanks ###########################
##################################################
#
#
# =================Other Configuration================
# Usages :
usage = "usage: %prog [options] "
# Version
Version="%prog 0.0.1"
# ====================================================
# Import Modules
import optparse, sys,os
from toolkit import processor as ps
def main():
   parser = optparse.OptionParser(usage = usage,version = Version)
   parser.add_option(
      '-i','--input',type = 'string',dest = 'inputfile',
      help = "File Input Path For Encryption", default = None)

   parser.add_option(
      '-o','--output',type = "string",dest = 'outputfile',
      help = "File Output Path For Saving Encrypter Cipher",default = ".")

   parser.add_option(
      '-p','--password',type = "string",dest = 'password',
      help = "Provide Password For Encrypting File",default = None)
      (options, args) =  parser.parse_args()
      # Input Conditions Checkings
      if not options.inputfile or not os.path.isfile(options.inputfile):
         print " [Error] Please Specify Input File Path"
         exit(0)
      if not options.outputfile or not os.path.isdir(options.outputfile):
         print " [Error] Please Specify Output Path"
         exit(0)
      if not options.password:
         print " [Error] No
         exit(0)
      inputfile = options.inputfile
      outputfile = options.outputfile
      password = options.password
      work = "D"
      ps.FileCipher(inputfile,outputfile,password,work)
      return
if __name__ == '__main__':
   main()

可以使用以下命令执行上述代码：

You can use the following command for executing the above code −

python pyfilecipher-decrypt.py -i encrypted_file_path -p password

Output

执行上述命令时，可以看到以下代码：

You can observe the following code when you execute the command shown above −

Note - 输出指定加密前和解密后的哈希值，这会记录加密相同的文件并且该过程成功。

Note − The output specifies the hash values before encryption and after decryption, which keeps a note that the same file is encrypted and the process was successful.