From 6a99c22cbca869558dcb2c5d5dd92cef67ce5665 Mon Sep 17 00:00:00 2001
From: jeffro256 <jeffro256@tutanota.com>
Date: Wed, 21 Jan 2026 00:44:49 -0600
Subject: [PATCH] rpc: return error gracefully on cryptonight v1 check

---
 .../cryptonote_format_utils.cpp               |  4 ++-
 src/cryptonote_config.h                       |  1 +
 src/rpc/core_rpc_server.cpp                   | 28 +++++++++++++++++--
 3 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/src/cryptonote_basic/cryptonote_format_utils.cpp b/src/cryptonote_basic/cryptonote_format_utils.cpp
index 0fa5161ef..f560fe77a 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.cpp
+++ b/src/cryptonote_basic/cryptonote_format_utils.cpp
@@ -1622,7 +1622,9 @@ namespace cryptonote
     }
     else // CryptoNight
     {
-      const int pow_variant = major_version >= 7 ? major_version - 6 : 0;
+      static_assert(HF_VERSION_CRYPTONIGHT_VARIANT_1 >= 1);
+      const int pow_variant = major_version >= HF_VERSION_CRYPTONIGHT_VARIANT_1
+        ? major_version - (HF_VERSION_CRYPTONIGHT_VARIANT_1 - 1) : 0;
       crypto::cn_slow_hash(block_hashing_blob.data(), block_hashing_blob.size(), res, pow_variant, height);
     }
 
diff --git a/src/cryptonote_config.h b/src/cryptonote_config.h
index 19b6f9ab8..31d3fd30f 100644
--- a/src/cryptonote_config.h
+++ b/src/cryptonote_config.h
@@ -174,6 +174,7 @@
 #define HF_VERSION_DYNAMIC_FEE                  4
 #define HF_VERSION_MIN_MIXIN_4                  6
 #define HF_VERSION_MIN_MIXIN_6                  7
+#define HF_VERSION_CRYPTONIGHT_VARIANT_1        7
 #define HF_VERSION_MIN_MIXIN_10                 8
 #define HF_VERSION_MIN_MIXIN_15                 15
 #define HF_VERSION_ENFORCE_RCT                  6
diff --git a/src/rpc/core_rpc_server.cpp b/src/rpc/core_rpc_server.cpp
index c1b5199f5..5b680b523 100644
--- a/src/rpc/core_rpc_server.cpp
+++ b/src/rpc/core_rpc_server.cpp
@@ -2081,6 +2081,20 @@ namespace cryptonote
       error_resp.message = "Wrong block blob";
       return false;
     }
+    if (req.major_version == HF_VERSION_CRYPTONIGHT_VARIANT_1 && req.major_version < RX_BLOCK_VERSION)
+    {
+      try
+      {
+        crypto::cn_variant1_check(blockblob.size(), /*variant=*/1);
+      }
+      catch(const std::exception& e)
+      {
+        error_resp.code = CORE_RPC_ERROR_CODE_WRONG_BLOCKBLOB_SIZE;
+        error_resp.message = "Block blob size is too small for CryptoNight v1, rejecting block";
+        return false;
+      }
+    }
+    
     if(!m_core.check_incoming_block_size(blockblob))
     {
       error_resp.code = CORE_RPC_ERROR_CODE_WRONG_BLOCKBLOB_SIZE;
@@ -2101,8 +2115,18 @@ namespace cryptonote
       buf.copy(reinterpret_cast<char *>(&seed_hash), sizeof(crypto::hash));
     }
 
-    cryptonote::get_block_longhash(&(m_core.get_blockchain_storage()), blockblob, pow_hash, req.height,
-      req.major_version, req.seed_hash.size() ? &seed_hash : NULL, 0);
+    try
+    {
+      cryptonote::get_block_longhash(&(m_core.get_blockchain_storage()), blockblob, pow_hash, req.height,
+        req.major_version, req.seed_hash.size() ? &seed_hash : NULL, 0);
+    }
+    catch (const std::exception &e)
+    {
+      MERROR("Caught unexpected error while hashing in " << __PRETTY_FUNCTION__ << ": " << e.what());
+      error_resp.code = CORE_RPC_ERROR_CODE_INTERNAL_ERROR;
+      error_resp.message = e.what();
+      return false;
+    }
     res = string_tools::pod_to_hex(pow_hash);
     return true;
   }