Merge pull request #71 from Xlgd/master

#58 fixed encode and decode text using key

Author: chavarera

projects/Get meta information of images/README.md

@@ -2,7 +2,7 @@
 
 ### usage
 
-python get_meta_from_pic image_name
+python get_meta_from_pic.py image_file
 
 ### note
 

projects/create script to encode and decode text/README.md

@@ -0,0 +1,7 @@
+## create script to encode and decode text
+
+### usage
+
+python aes_encode.py file.txt
+
+An encrypted file("encrypted.bin") will be generated after the program is run

projects/create script to encode and decode text/aes_encode.py

@@ -0,0 +1,39 @@
+from Cryptodome.Cipher import AES
+from Cryptodome import Random
+from binascii import b2a_hex
+import sys
+
+# get the plaintext
+f = open(sys.argv[1])
+plain_text = f.read()
+
+# The key length must be 16 (AES-128), 24 (AES-192), or 32 (AES-256) Bytes.
+key = b'this is a 16 key'
+
+# Generate a non-repeatable key vector with a length equal to the size of the AES block
+iv = Random.new().read(AES.block_size)
+
+# Use key and iv to initialize AES object, use MODE_CFB mode
+mycipher = AES.new(key, AES.MODE_CFB, iv)
+
+# Add iv (key vector) to the beginning of the encrypted ciphertext and transmit it together
+ciphertext = iv + mycipher.encrypt(plain_text.encode())
+
+
+# To decrypt, use key and iv to generate a new AES object
+mydecrypt = AES.new(key, AES.MODE_CFB, ciphertext[:16])
+
+# Use the newly generated AES object to decrypt the encrypted ciphertext
+decrypttext = mydecrypt.decrypt(ciphertext[16:])
+
+# output
+file_out = open("encrypted.bin", "wb")
+file_out.write(ciphertext[16:])
+file_out.close()
+
+print("The key k is: ", key)
+print("iv is: ", b2a_hex(ciphertext)[:16])
+print("The encrypted data is: ", b2a_hex(ciphertext)[16:])
+print("The decrypted data is: ", decrypttext.decode())
+
+f.close()