Create main.py

scripts/RSA_algo_EtoE_Encryption/main.py

@@ -0,0 +1,74 @@
+import rsa
+
+
+##this function generates the keys
+def generate_keys():
+    (pubKey, privKey) = rsa.newkeys(1024)
+    with open('keys/pubkey.pem', 'wb') as f:
+        f.write(pubKey.save_pkcs1('PEM'))
+
+    with open('keys/privkey.pem', 'wb') as f:
+        f.write(privKey.save_pkcs1('PEM'))
+
+##Loads the keys from the .pem files to pubkey and privkey variables
+def load_keys():
+    with open('keys/pubkey.pem', 'rb') as f:
+        pubKey = rsa.PublicKey.load_pkcs1(f.read())
+
+    with open('keys/privkey.pem', 'rb') as f:
+        privKey = rsa.PrivateKey.load_pkcs1(f.read())
+
+    return pubKey, privKey
+
+##encrypts the messages using the public key
+def encrypt(msg, key):
+    return rsa.encrypt(msg.encode('ascii'), key)
+
+##decrypts the encrypted message or ciphertext using the privatekey
+def decrypt(ciphertext, key):
+    try:
+        return rsa.decrypt(ciphertext, key).decode('ascii')
+    except:
+        return False
+
+##the sha is generated for the message and key
+def sign_sha1(msg, key):
+    return rsa.sign(msg.encode('ascii'), key, 'SHA-1')
+
+##this function verifies the sha
+def verify_sha1(msg, signature, key):
+    try:
+        return rsa.verify(msg.encode('ascii'), signature, key) == 'SHA-1'
+    except:
+        return False
+
+##generates keys
+generate_keys()
+
+##loads keys
+pubKey, privKey = load_keys()
+
+##Takes in the message and encrypts it
+message = input('Enter a message:')
+ciphertext = encrypt(message, pubKey)
+
+signature = sign_sha1(message, privKey)
+
+##It then decrypts the message.
+plaintext = decrypt(ciphertext, privKey)
+
+##the cipher of the message is displayed
+print(f'Cipher text: {ciphertext}')
+##the sgnature of the message is displayed
+print(f'Signature: {signature}')
+
+##the decrypted message is displayed
+if plaintext:
+    print(f'Plain text: {plaintext}')
+else:
+    print('Could not decrypt the message.')
+
+if verify_sha1(plaintext, signature, pubKey):
+    print('Signature verified!')
+else:
+    print('Could not verify the message signature.')