add support for ctAddress

Author: spencer-xyz

README.md

@@ -246,7 +246,30 @@ int_cipher_text, signature = build_string_input_text(plaintext, user_aes_key, se
 
 - `input_text`: A dictionary of the form { "ciphertext": { "value": int[] }, "signature": bytes[] }
 
-### 9. `generate_rsa_keypair()`
+### 9. `build_address_input_text(plaintext, user_aes_key, sender, contract, func_selector, signing_key)`
+
+**Purpose:** Builds input text by encrypting the plaintext and signing it.
+
+**Usage:**
+
+```python
+int_cipher_text, signature = build_address_input_text(plaintext, user_aes_key, sender, contract, func_selector, signing_key)
+```
+
+**Parameters:**
+
+- `plaintext`: The plaintext message.
+- `user_aes_key`: The user's AES key.
+- `sender`: The sender's address.
+- `contract`: The contract address.
+- `func_selector`: The function selector.
+- `signing_key`: The private key used for signing.
+
+**Returns:**
+
+- `input_text`: A dictionary of the form { "ciphertext": { "ct1": int, "ct2": int, "ct3": int }, "signature1": bytes, "signature2": bytes, "signature3": bytes }
+
+### 10. `generate_rsa_keypair()`
 
 **Purpose:** Generates an RSA key pair.
 
@@ -261,7 +284,7 @@ private_key_bytes, public_key_bytes = generate_rsa_keypair()
 - `private_key_bytes`: The serialized private key.
 - `public_key_bytes`: The serialized public key.
 
-### 10. `encrypt_rsa(public_key_bytes, plaintext)`
+### 11. `encrypt_rsa(public_key_bytes, plaintext)`
 
 **Purpose:** Encrypts plaintext using RSA encryption with a provided public key.
 
@@ -280,7 +303,7 @@ ciphertext = encrypt_rsa(public_key_bytes, plaintext)
 
 - `ciphertext`: The encrypted message.
 
-### 11. `decrypt_rsa(private_key_bytes, ciphertext)`
+### 12. `decrypt_rsa(private_key_bytes, ciphertext)`
 
 **Purpose:** Decrypts ciphertext using RSA decryption with a provided private key.
 
@@ -299,7 +322,7 @@ plaintext = decrypt_rsa(private_key_bytes, ciphertext)
 
 - `plaintext`: The decrypted message.
 
-### 12. `decrypt_uint(ciphertext, user_key)`
+### 13. `decrypt_uint(ciphertext, user_key)`
 
 **Purpose:** Decrypts a value stored in a contract using a user key
 
@@ -318,7 +341,7 @@ plaintext = decrypt_uint(ciphertext, user_key)
 
 - `result`: The decrypted value.
 
-### 13. `decrypt_string(ciphertext, user_key)`
+### 14. `decrypt_string(ciphertext, user_key)`
 
 **Purpose:** Decrypts a value stored in a contract using a user key
 
@@ -337,6 +360,25 @@ plaintext = decrypt_string(ciphertext, user_key)
 
 - `result`: The decrypted value.
 
+### 15. `decrypt_address(ciphertext, user_key)`
+
+**Purpose:** Decrypts a value stored in a contract and encrypted using a user key
+
+**Usage:**
+
+```python
+plaintext = decrypt_string(ciphertext, user_key)
+```
+
+**Parameters:**
+
+- `ciphertext`: A dictionary of the form { "ct1": int, "ct2": int, "ct3": int } where each cell holds a portion of the address encrypted
+- `userKey`: The user's AES key.
+
+**Returns:**
+
+- `result`: The decrypted address.
+
 # Utilities (utils.py) Functions
 
 ### 1. `web3_connected(web3)`

coti/crypto_utils.py

@@ -6,6 +6,7 @@
 from cryptography.hazmat.primitives.asymmetric import rsa
 from eth_keys import keys
 from math import ceil
+from web3 import Web3
 
 block_size = AES.block_size
 address_size = 20
@@ -153,6 +154,47 @@ def build_string_input_text(plaintext, user_aes_key, sender, contract, function_
 
     return input_text
 
+def build_address_input_text(plaintext, user_aes_key, sender, contract, function_selector, signing_key):
+    ct_int_1, sig_1 = build_input_text(
+        int(plaintext[2:18], 16), # bytes 1 - 8
+        user_aes_key,
+        sender,
+        contract,
+        function_selector,
+        signing_key
+    )
+
+    ct_int_2, sig_2 = build_input_text(
+        int(plaintext[18:34], 16), # bytes 9 - 16
+        user_aes_key,
+        sender,
+        contract,
+        function_selector,
+        signing_key
+    )
+
+    ct_int_3, sig_3 = build_input_text(
+        int(plaintext[34:42], 16), # bytes 17 - 20
+        user_aes_key,
+        sender,
+        contract,
+        function_selector,
+        signing_key
+    )
+    
+    input_text = {
+        'ciphertext': {
+            'ct1': ct_int_1,
+            'ct2': ct_int_2,
+            'ct3': ct_int_3
+        },
+        'signature1': sig_1,
+        'signature2': sig_2,
+        'signature3': sig_3
+    }
+    
+    return input_text
+
 
 def decrypt_uint(ciphertext, user_key):
     # Convert ct to bytes (big-endian)
@@ -194,6 +236,28 @@ def decrypt_string(ciphertext, user_key):
 
     return decrypted_string.strip('\0')
 
+def decrypt_address(ciphertext, user_key):
+    if isinstance(ciphertext, list): # format when reading ciphertext from a state variable
+        __ciphertext = ciphertext
+    else: # format when reading ciphertext from an event
+        __ciphertext = list(ciphertext.values())
+
+    addr = '0x'
+    
+    decrypted = decrypt_uint(__ciphertext[0], user_key)
+
+    addr += hex(decrypted)[2:].rjust(16, '0') # 8 bytes is 16 characters
+
+    decrypted = decrypt_uint(__ciphertext[1], user_key)
+
+    addr += hex(decrypted)[2:].rjust(16, '0') # 8 bytes is 16 characters
+
+    decrypted = decrypt_uint(__ciphertext[2], user_key)
+
+    addr += hex(decrypted)[2:].rjust(8, '0') # 4 bytes is 8 characters
+    
+    return Web3.to_checksum_address(addr)
+
 
 def generate_rsa_keypair():
     # Generate RSA key pair