decrypt function updated and authentication enabled for key images raw data

src/page.h

@@ -2027,11 +2027,15 @@ namespace xmreg {
             }
 
             // decrypt key images data using private view key
-            // dont use authentication (i.e., false), as we are
-            // not interested if this key image data is properly signed
             decoded_raw_data = xmreg::decrypt(
                     std::string(decoded_raw_data, magiclen),
-                    prv_view_key, false);
+                    prv_view_key, true);
+
+            if (decoded_raw_data.empty())
+            {
+                return string {"Failed to authenticate key images data. "
+                               "Maybe wrong viewkey was porvided?"};
+            }
 
             // header is public spend and keys
             const size_t header_lenght = 2 * sizeof(crypto::public_key);
@@ -2039,13 +2043,6 @@ namespace xmreg {
             const size_t record_lenght = key_img_size + sizeof(crypto::signature);
             const size_t chacha_length = sizeof(crypto::chacha8_key);
 
-
-//            cout << header_lenght << endl;
-//            cout << key_img_size << endl;
-//            cout << record_lenght << endl;
-//            cout << decoded_raw_data.size() - header_lenght << endl;
-//            cout << (decoded_raw_data.size() - header_lenght) % record_lenght << endl;
-
             if (decoded_raw_data.size() < header_lenght)
             {
                 cerr << "Bad data size from submitted key images raw data" << endl;

src/tools.cpp

@@ -793,16 +793,18 @@ namespace xmreg
             const crypto::secret_key &skey,
             bool authenticated)
     {
+
+        const size_t prefix_size = sizeof(chacha8_iv)
+                                   + (authenticated ? sizeof(crypto::signature) : 0);
+
         crypto::chacha8_key key;
 
         crypto::generate_chacha8_key(&skey, sizeof(skey), key);
 
         const crypto::chacha8_iv &iv = *(const crypto::chacha8_iv*)&ciphertext[0];
-
         std::string plaintext;
 
-        plaintext.resize(ciphertext.size() - sizeof(iv) -
+        plaintext.resize(ciphertext.size() - prefix_size);
-                                 (authenticated ? sizeof(crypto::signature) : 0));
 
         if (authenticated)
         {
@@ -811,8 +813,9 @@ namespace xmreg
             crypto::public_key pkey;
             crypto::secret_key_to_public_key(skey, pkey);
 
-            const crypto::signature &signature
+            const crypto::signature &signature =
-                    = *(const crypto::signature*)&ciphertext[ciphertext.size() - sizeof(crypto::signature)];
+                    *(const crypto::signature*)&ciphertext[ciphertext.size()
+                                                           - sizeof(crypto::signature)];
 
             if (!crypto::check_signature(hash, pkey, signature))
             {
@@ -822,10 +825,9 @@ namespace xmreg
 
         }
 
-        crypto::chacha8(
+        crypto::chacha8(ciphertext.data() + sizeof(iv),
-                ciphertext.data() + sizeof(iv),
+                        ciphertext.size() - prefix_size,
-                ciphertext.size() - sizeof(iv),
+                        key, iv, &plaintext[0]);
-                key, iv, &plaintext[0]);
 
         return plaintext;
     }