Support message separation for multiple inputs from same user. (#142)

src/crypto.cpp

@@ -35,8 +35,8 @@ namespace crypto
         seckey[0] = KEYPFX_ed25519;
 
         crypto_sign_ed25519_keypair(
-            reinterpret_cast<unsigned char *>(pubkey.data() + 1),   // +1 to skip the prefix byte.
-            reinterpret_cast<unsigned char *>(seckey.data() + 1));  // +1 to skip the prefix byte.
+            reinterpret_cast<unsigned char *>(pubkey.data() + 1),  // +1 to skip the prefix byte.
+            reinterpret_cast<unsigned char *>(seckey.data() + 1)); // +1 to skip the prefix byte.
     }
 
     /**
@@ -196,4 +196,26 @@ namespace crypto
         return hash;
     }
 
+    /**
+     * Generates blake3 hash for the given string view vector using stream hashing.
+     */
+    std::string get_hash(const std::vector<std::string_view> &sw_vect)
+    {
+        std::string hash;
+        hash.resize(BLAKE3_OUT_LEN);
+
+        // Init stream hashing.
+        blake3_hasher hasher;
+        blake3_hasher_init(&hasher);
+
+        // Hash is generated only using message in contract output struct.
+        for (std::string_view sw : sw_vect)
+            blake3_hasher_update(&hasher, reinterpret_cast<const unsigned char *>(sw.data()), sw.length());
+
+        // Get the final hash.
+        blake3_hasher_finalize(&hasher, reinterpret_cast<unsigned char *>(hash.data()), hash.length());
+
+        return hash;
+    }
+
 } // namespace crypto