Update

unit02_symmetric/src/d_01.py

@@ -1,35 +1,56 @@
-from Crypto.Cipher import AES
+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes 
+from cryptography.hazmat.primitives import padding
+from cryptography.hazmat.backends import default_backend
+
 import hashlib
 import sys
 import binascii
-import Padding
 
 val='hello'
-password='hello'
+password='hello123'
 
 plaintext=val
 
 def encrypt(plaintext,key, mode):
-	encobj = AES.new(key,mode)
-	return(encobj.encrypt(plaintext))
+    method=algorithms.AES(key)
+    cipher = Cipher(method,mode, default_backend())
+    encryptor = cipher.encryptor()
+    ct = encryptor.update(plaintext) + encryptor.finalize()
+    return(ct)
 
 def decrypt(ciphertext,key, mode):
-	encobj = AES.new(key,mode)
-	return(encobj.decrypt(ciphertext))
+    method=algorithms.AES(key)
+    cipher = Cipher(method, mode, default_backend())
+    decryptor = cipher.decryptor()
+    pl = decryptor.update(ciphertext) + decryptor.finalize()
+    return(pl)
+
+def pad(data,size=128):
+    padder = padding.PKCS7(size).padder()
+    padded_data = padder.update(data)
+    padded_data += padder.finalize()
+    return(padded_data)
+
+def unpad(data,size=128):
+    padder = padding.PKCS7(size).unpadder()
+    unpadded_data = padder.update(data)
+    unpadded_data += padder.finalize()
+    return(unpadded_data)
 
 key = hashlib.sha256(password.encode()).digest()
 
+print("Before padding: ",plaintext)
 
-plaintext = Padding.appendPadding(plaintext,blocksize=Padding.AES_blocksize,mode='CMS')
+plaintext=pad(plaintext.encode())
 
-print("After padding (CMS): ",binascii.hexlify(bytearray(plaintext.encode())))
+print("After padding (CMS): ",binascii.hexlify(bytearray(plaintext)))
 
-ciphertext = encrypt(plaintext.encode(),key,AES.MODE_ECB)
+ciphertext = encrypt(plaintext,key,modes.ECB())
 print("Cipher (ECB): ",binascii.hexlify(bytearray(ciphertext)))
 
-plaintext = decrypt(ciphertext,key,AES.MODE_ECB)
+plaintext = decrypt(ciphertext,key,modes.ECB())
+
+plaintext = unpad(plaintext)
+print("  decrypt: ",plaintext.decode())
 
-plaintext = Padding.removePadding(plaintext.decode(),mode='CMS')
-print("  decrypt: ",plaintext)
 
-plaintext=val

unit02_symmetric/src/g_01.py

@@ -0,0 +1,33 @@
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.ciphers.aead import ChaCha20Poly1305
+import sys
+import binascii
+from cryptography.hazmat.backends import default_backend
+
+
+msg = "edinburgh"
+key = "qwerty"
+
+if (len(sys.argv)>1):
+	msg=str(sys.argv[1])
+
+if (len(sys.argv)>2):
+	key=str(sys.argv[2])
+
+print ("Data:\t",msg)
+print ("Key:\t",key)
+
+digest = hashes.Hash(hashes.SHA256(),default_backend())
+digest.update(key.encode())
+k=digest.finalize()
+
+chacha = ChaCha20Poly1305(k)
+nonce = '\0\0\0\0\0\0\0\0\0\0\0\0'
+add=''
+cipher = chacha.encrypt(nonce.encode(), msg.encode(), add.encode())
+rtn=chacha.decrypt(nonce.encode(), cipher, add.encode())
+
+print ("\nKey:\t",binascii.b2a_hex(key.encode()).decode())
+print ("Nonce:\t",binascii.b2a_hex(nonce.encode()).decode())
+print ("\nCipher:\t",binascii.b2a_hex(cipher).decode())
+print ("Decrypted:\t",rtn.decode())

unit02_symmetric/src/g_02.py

@@ -0,0 +1,38 @@
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms
+import sys
+import binascii
+from cryptography.hazmat.backends import default_backend
+
+
+
+
+msg = "edinburgh"
+key = "qwerty"
+
+if (len(sys.argv)>1):
+	msg=str(sys.argv[1])
+
+if (len(sys.argv)>2):
+	key=str(sys.argv[2])
+
+print ("Data:\t",msg)
+print ("Key:\t",key)
+
+digest = hashes.Hash(hashes.SHA256(),default_backend())
+digest.update(key.encode())
+k=digest.finalize()
+
+algorithm = algorithms.ARC4(k)
+cipher = Cipher(algorithm, mode=None, backend=default_backend())
+encryptor = cipher.encryptor()
+ct = encryptor.update(msg.encode())
+pt = cipher.decryptor()
+pt=pt.update(ct)
+
+
+
+print ("\nKey:\t",binascii.b2a_hex(key.encode()).decode())
+
+print ("\nCipher:\t",binascii.b2a_hex(ct).decode())
+print ("Decrypted:\t",pt.decode())

unit02_symmetric/src/old/d_01.py

@@ -0,0 +1,35 @@
+from Crypto.Cipher import AES
+import hashlib
+import sys
+import binascii
+import Padding
+
+val='hello'
+password='hello'
+
+plaintext=val
+
+def encrypt(plaintext,key, mode):
+	encobj = AES.new(key,mode)
+	return(encobj.encrypt(plaintext))
+
+def decrypt(ciphertext,key, mode):
+	encobj = AES.new(key,mode)
+	return(encobj.decrypt(ciphertext))
+
+key = hashlib.sha256(password.encode()).digest()
+
+
+plaintext = Padding.appendPadding(plaintext,blocksize=Padding.AES_blocksize,mode='CMS')
+
+print("After padding (CMS): ",binascii.hexlify(bytearray(plaintext.encode())))
+
+ciphertext = encrypt(plaintext.encode(),key,AES.MODE_ECB)
+print("Cipher (ECB): ",binascii.hexlify(bytearray(ciphertext)))
+
+plaintext = decrypt(ciphertext,key,AES.MODE_ECB)
+
+plaintext = Padding.removePadding(plaintext.decode(),mode='CMS')
+print("  decrypt: ",plaintext)
+
+plaintext=val