RSA encryption and decryption in Python

Question

I need help using RSA encryption and decryption in Python    I am creating a private public key pair  encrypting a message with keys and writing message to a file  Then I am reading ciphertext from file and decrypting text using key    I am having trouble with the decryption portion  As you can see in my code below  when I put in decrypted   key decrypt message  that the program works  yet the decrypted message is encrypted again  It seems like it is not reading the ciphertext from the file    Can anyone help me write this code so decryption reads ciphertext from file and then uses key to decrypt ciphertext   import Crypto from Crypto PublicKey import RSA from Crypto import Random  random generator   Random new   read key   RSA generate 1024  random generator   generate public and private keys  publickey   key publickey   pub key export for exchange  encrypted   publickey encrypt  encrypt this message   32   message to encrypt is in the above line  encrypt this message   print  encrypted message    encrypted  ciphertext  f   open   encryption txt    w w  f write str encrypted    write ciphertext to file f close     decrypted code below  f   open   encryption txt    r   message   f read    decrypted   key decrypt message   print  decrypted   decrypted  f   open   encryption txt    w   f write str message   f write str decrypted   f close

User · Answer

Here is my implementation for python 3 and pycrypto  from Crypto PublicKey import RSA key   RSA generate 4096  f   open   home john Desktop my rsa public pem    wb   f write key publickey   exportKey  PEM    f close   f   open   home john Desktop my rsa private pem    wb   f write key exportKey  PEM    f close    f   open   home john Desktop my rsa public pem    rb   f1   open   home john Desktop my rsa private pem    rb   key   RSA importKey f read    key1   RSA importKey f1 read     x   key encrypt b dddddd  32   print x  z   key1 decrypt x  print z

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PKCS 1 OAEP is an asymmetric cipher based on RSA and the OAEP padding  from Crypto PublicKey import RSA from Crypto import Random from Crypto Cipher import PKCS1 OAEP   def rsa encrypt decrypt        key   RSA generate 2048      private key   key export key  PEM       public key   key publickey   exportKey  PEM       message   input  plain text for RSA encryption and decryption        message   str encode message       rsa public key   RSA importKey public key      rsa public key   PKCS1 OAEP new rsa public key      encrypted text   rsa public key encrypt message       encrypted text   b64encode encrypted text       print  your encrypted text is       format encrypted text         rsa private key   RSA importKey private key      rsa private key   PKCS1 OAEP new rsa private key      decrypted text   rsa private key decrypt encrypted text       print  your decrypted text is       format decrypted text

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coding  utf-8 from   future   import unicode literals import base64 import os  import six from Crypto import Random from Crypto PublicKey import RSA   class PublicKeyFileExists Exception   pass   class RSAEncryption object       PRIVATE KEY FILE PATH   None     PUBLIC KEY FILE PATH   None      def encrypt self  message           public key   self  get public key           public key object   RSA importKey public key          random phrase    M          encrypted message   public key object encrypt self  to format for encrypt message   random phrase  0            use base64 for save encrypted message in database without problems with encoding         return base64 b64encode encrypted message       def decrypt self  encoded encrypted message           encrypted message   base64 b64decode encoded encrypted message          private key   self  get private key           private key object   RSA importKey private key          decrypted message   private key object decrypt encrypted message          return six text type decrypted message  encoding  utf8        def generate keys self              Be careful rewrite your keys            random generator   Random new   read         key   RSA generate 1024  random generator          private  public   key exportKey    key publickey   exportKey            if os path isfile self PUBLIC KEY FILE PATH               raise PublicKeyFileExists                                                             self create directories            with open self PRIVATE KEY FILE PATH   w   as private file              private file write private          with open self PUBLIC KEY FILE PATH   w   as public file              public file write public          return private  public      def create directories self  for private key True           public key path   self PUBLIC KEY FILE PATH rsplit      1          if not os path exists public key path               os makedirs public key path          if for private key              private key path   self PRIVATE KEY FILE PATH rsplit      1              if not os path exists private key path                   os makedirs private key path       def  get public key self              run generate keys   before get keys             with open self PUBLIC KEY FILE PATH   r   as  file              return  file read        def  get private key self              run generate keys   before get keys             with open self PRIVATE KEY FILE PATH   r   as  file              return  file read        def  to format for encrypt value           if isinstance value  int               return six binary type value          for str type in six string types              if isinstance value  str type                   return value encode  utf8           if isinstance value  six binary type               return value   And use  KEYS DIRECTORY   settings SURVEY DIR WITH ENCRYPTED KEYS  class TestingEncryption RSAEncryption       PRIVATE KEY FILE PATH   KEYS DIRECTORY    private key      PUBLIC KEY FILE PATH   KEYS DIRECTORY    public key      django flask from django core files import File  class ProductionEncryption RSAEncryption       PUBLIC KEY FILE PATH   settings SURVEY DIR WITH ENCRYPTED KEYS    public key       def  get private key self              run generate keys   before get keys             from corportal utils import global elements         private key   global elements request FILES get  private key           if private key              private key file   File private key              return private key file read    message    Hello     friend  encrypted mes   ProductionEncryption   encrypt message  decrypted mes   ProductionEncryption   decrypt message

User · Answer

Watch out using Crypto     It is a wonderful library but it has an issue in python3 8  cause from the library time was removed the attribute clock    To fix it just modify the source in  usr lib python3 8 site-packages Crypto Random  UserFriendlyRNG pyline 77 changing t   time clock   int t   time perf counter

User · Answer

You can  use simple way for genarate RSA   Use rsa library   pip install rsa

User · Answer

In order to make it work you need to convert key from str to tuple before decryption ast literal eval function   Here is fixed code   import Crypto from Crypto PublicKey import RSA from Crypto import Random import ast  random generator   Random new   read key   RSA generate 1024  random generator   generate pub and priv key  publickey   key publickey     pub key export for exchange  encrypted   publickey encrypt  encrypt this message   32   message to encrypt is in the above line  encrypt this message   print  encrypted message    encrypted  ciphertext f   open   encryption txt    w   f write str encrypted    write ciphertext to file f close     decrypted code below  f   open  encryption txt    r   message   f read     decrypted   key decrypt ast literal eval str encrypted     print  decrypted   decrypted  f   open   encryption txt    w   f write str message   f write str decrypted   f close

[python] RSA encryption and decryption in Python

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