From 16fb32cf351aca678dd6bafaa86a319647efc33a Mon Sep 17 00:00:00 2001
From: Kaushal Kumar Agarwal <kaushalag29@gmail.com>
Date: Thu, 21 Jun 2018 20:44:47 +0530
Subject: [PATCH] Issue Why recovered key using shares is not the same as
 key?Even though the string part is matching but then also decryption is not
 possible.Go through the comments in code to get better explanation.

---
 Check.py | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)
 create mode 100644 Check.py

diff --git a/Check.py b/Check.py
new file mode 100644
index 0000000..406eadb
--- /dev/null
+++ b/Check.py
@@ -0,0 +1,94 @@
+from secretsharing import PlaintextToHexSecretSharer
+import subprocess
+import json
+import os
+from Crypto.Cipher import AES
+
+# This function splits the secret and returns a list of shares
+def splitSecret(secret,threshold,splits):
+	shares = PlaintextToHexSecretSharer.split_secret(secret, threshold, splits)
+	return shares
+
+# This function recovers the secret using the list of shares and returns the reconstructed secret
+def recoverSecret(shares):
+	secret = PlaintextToHexSecretSharer.recover_secret(shares)
+	return secret
+
+
+def pad(data):
+    padding = 16 - len(data) % 16
+    return data + padding * ' '
+
+
+def unpad(data):
+    return data[:length]
+
+
+def keyGen():
+    # Generating random key of 32 bytes
+    key = os.urandom(32)
+    # print("Key Generated")
+    # print(key)
+    return key
+
+
+def encryptMsg(plaintext, key):
+    # Initialization vector in AES should be 16 bytes
+    IV = 16 * '\x00'
+    # Creation of encryptor and decryptor object using above details
+    cipher = AES.new(key, AES.MODE_CBC, IV)
+    return cipher.encrypt(pad(plaintext))
+
+
+def decryptMsg(ciphertext, key):
+    # Initialization vector in AES should be 16 bytes
+    IV = 16 * '\x00'
+    # Creation of encryptor and decryptor object using above details
+    cipher = AES.new(key, AES.MODE_CBC, IV)
+    return unpad(cipher.decrypt(ciphertext));
+
+
+msg = input('Enter The Message To Be Encrypted : ')
+length = len(msg)
+key = keyGen()
+print("Key generated : " + str(key))
+
+#Enter Threshold And No of splits for key
+threshold=0
+splits=0
+while(True):
+    splits=input('Enter Max No of splits\n')
+    splits=int(splits)
+    threshold=input('Enter Threshold Value\n')
+    threshold=int(threshold)
+    if(splits>=threshold and threshold>=2):
+        break
+    else:
+        print("Please Choose Correct Pair Of values bcoz threshold<=split and threshold>=2")
+
+#Formatting key inorder to remove b' at the beginning and ' in the end
+key_formatted=str(key)
+key_formatted=key_formatted[2:-1]
+print("Formatted Key="+key_formatted)
+#Generating shares of formatted key
+shared_key=splitSecret(key_formatted,threshold,splits)
+print("Shared Keys="+str(shared_key))
+
+#Recovering Keys using first threshold
+recovered_key=recoverSecret(shared_key[:threshold])
+#Converting recovered_key to bytes
+recovered_key=recovered_key.encode()
+print("Recovered Key="+str(recovered_key))
+print(type(recovered_key))
+
+#issue why recovered key!=key?
+if(recovered_key==key):
+    print("True")
+
+#Encryption using key generated
+ciphertext = encryptMsg(msg,key)
+print("Encrypted Text : " + str(ciphertext))
+
+#Decryption using recovered key gives error(issue)
+plaintext = decryptMsg(ciphertext,recovered_key)
+print("Decrypted Text : " + str(plaintext))