Merge pull request #8178

5d388eb Bump ring size to 16 for v15 & remove set default in wallet cli (j-berman)

1 files changed, 15 insertions, 9 deletions

diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 0b6a3abf3..5b7b4353d 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -3321,7 +3321,7 @@ bool Blockchain::check_tx_inputs(transaction& tx, tx_verification_context &tvc,
     size_t n_unmixable = 0, n_mixable = 0;
     size_t min_actual_mixin = std::numeric_limits<size_t>::max();
     size_t max_actual_mixin = 0;
-    const size_t min_mixin = hf_version >= HF_VERSION_MIN_MIXIN_10 ? 10 : hf_version >= HF_VERSION_MIN_MIXIN_6 ? 6 : hf_version >= HF_VERSION_MIN_MIXIN_4 ? 4 : 2;
+    const size_t min_mixin = hf_version >= HF_VERSION_MIN_MIXIN_15 ? 15 : hf_version >= HF_VERSION_MIN_MIXIN_10 ? 10 : hf_version >= HF_VERSION_MIN_MIXIN_6 ? 6 : hf_version >= HF_VERSION_MIN_MIXIN_4 ? 4 : 2;
     for (const auto& txin : tx.vin)
     {
       // non txin_to_key inputs will be rejected below
@@ -3364,14 +3364,11 @@ bool Blockchain::check_tx_inputs(transaction& tx, tx_verification_context &tvc,
       }
     }
 
-    if (((hf_version == HF_VERSION_MIN_MIXIN_10 || hf_version == HF_VERSION_MIN_MIXIN_10+1) && min_actual_mixin != 10) || (hf_version >= HF_VERSION_MIN_MIXIN_10+2 && min_actual_mixin > 10))
-    {
-      MERROR_VER("Tx " << get_transaction_hash(tx) << " has invalid ring size (" << (min_actual_mixin + 1) << "), it should be 11");
-      tvc.m_low_mixin = true;
-      return false;
-    }
-
-    if (min_actual_mixin < min_mixin)
+    // The only circumstance where ring sizes less than expected are
+    // allowed is when spending unmixable non-RCT outputs in the chain.
+    // Caveat: at HF_VERSION_MIN_MIXIN_15, temporarily allow ring sizes
+    // of 11 to allow a grace period in the transition to larger ring size.
+    if (min_actual_mixin < min_mixin && !(hf_version == HF_VERSION_MIN_MIXIN_15 && min_actual_mixin == 10))
     {
       if (n_unmixable == 0)
       {
@@ -3385,6 +3382,15 @@ bool Blockchain::check_tx_inputs(transaction& tx, tx_verification_context &tvc,
         tvc.m_low_mixin = true;
         return false;
       }
+    } else if ((hf_version > HF_VERSION_MIN_MIXIN_15 && min_actual_mixin > 15)
+      || (hf_version == HF_VERSION_MIN_MIXIN_15 && min_actual_mixin != 15 && min_actual_mixin != 10) // grace period to allow either 15 or 10
+      || (hf_version < HF_VERSION_MIN_MIXIN_15 && hf_version >= HF_VERSION_MIN_MIXIN_10+2 && min_actual_mixin > 10)
+      || ((hf_version == HF_VERSION_MIN_MIXIN_10 || hf_version == HF_VERSION_MIN_MIXIN_10+1) && min_actual_mixin != 10)
+    )
+    {
+      MERROR_VER("Tx " << get_transaction_hash(tx) << " has invalid ring size (" << (min_actual_mixin + 1) << "), it should be " << (min_mixin + 1));
+      tvc.m_low_mixin = true;
+      return false;
     }
 
     // min/max tx version based on HF, and we accept v1 txes if having a non mixable