From 0f450672b19c2bd4c501ce1e3c9105919c6d9ba7 Mon Sep 17 00:00:00 2001
From: Eli Ribble <eli@theribbles.org>
Date: Tue, 7 Nov 2023 15:07:54 -0700
Subject: [PATCH] Pull out a main function, remove global state.

Makes it easier to see what inputs I need.
---
 temp/ecc-hybrid-encryption-example.py | 38 +++++++++++++++------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/temp/ecc-hybrid-encryption-example.py b/temp/ecc-hybrid-encryption-example.py
index a78b6cb..b444a1b 100644
--- a/temp/ecc-hybrid-encryption-example.py
+++ b/temp/ecc-hybrid-encryption-example.py
@@ -17,9 +17,8 @@ def ecc_point_to_256_bit_key(point):
     sha.update(int.to_bytes(point.y, 32, 'big'))
     return sha.digest()
 
-curve = registry.get_curve('brainpoolP256r1')
 
-def encrypt_ECC(msg, pubKey):
+def encrypt_ECC(curve, msg, pubKey):
     ciphertextPrivKey = secrets.randbelow(curve.field.n)
     sharedECCKey = ciphertextPrivKey * pubKey
     secretKey = ecc_point_to_256_bit_key(sharedECCKey)
@@ -34,20 +33,25 @@ def decrypt_ECC(encryptedMsg, privKey):
     plaintext = decrypt_AES_GCM(ciphertext, nonce, authTag, secretKey)
     return plaintext
 
-msg = b'Text to be encrypted by ECC public key and ' \
-      b'decrypted by its corresponding ECC private key'
-print("original msg:", msg)
-privKey = secrets.randbelow(curve.field.n)
-pubKey = privKey * curve.g
+def main():
+	curve = registry.get_curve('brainpoolP256r1')
+	msg = b'Text to be encrypted by ECC public key and ' \
+		  b'decrypted by its corresponding ECC private key'
+	print("original msg:", msg)
+	privKey = secrets.randbelow(curve.field.n)
+	pubKey = privKey * curve.g
 
-encryptedMsg = encrypt_ECC(msg, pubKey)
-encryptedMsgObj = {
-    'ciphertext': binascii.hexlify(encryptedMsg[0]),
-    'nonce': binascii.hexlify(encryptedMsg[1]),
-    'authTag': binascii.hexlify(encryptedMsg[2]),
-    'ciphertextPubKey': hex(encryptedMsg[3].x) + hex(encryptedMsg[3].y % 2)[2:]
-}
-print("encrypted msg:", encryptedMsgObj)
+	encryptedMsg = encrypt_ECC(curve, msg, pubKey)
+	encryptedMsgObj = {
+		'ciphertext': binascii.hexlify(encryptedMsg[0]),
+		'nonce': binascii.hexlify(encryptedMsg[1]),
+		'authTag': binascii.hexlify(encryptedMsg[2]),
+		'ciphertextPubKey': hex(encryptedMsg[3].x) + hex(encryptedMsg[3].y % 2)[2:]
+	}
+	print("encrypted msg:", encryptedMsgObj)
 
-decryptedMsg = decrypt_ECC(encryptedMsg, privKey)
-print("decrypted msg:", decryptedMsg)
+	decryptedMsg = decrypt_ECC(encryptedMsg, privKey)
+	print("decrypted msg:", decryptedMsg)
+
+if __name__ == "__main__":
+	main()