From 0cd530e4dba40331eeac135035934a651ab250c3 Mon Sep 17 00:00:00 2001
From: p4u <pau@dabax.net>
Date: Fri, 8 Sep 2023 00:07:42 +0200
Subject: [PATCH] fix anonymous maxCensusSize check

Signed-off-by: p4u <pau@dabax.net>
---
 crypto/zk/circuit/config.go        |  8 +++++---
 vochain/transaction/election_tx.go | 20 +++++++++-----------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/crypto/zk/circuit/config.go b/crypto/zk/circuit/config.go
index 026d8c81d..d589e7cea 100644
--- a/crypto/zk/circuit/config.go
+++ b/crypto/zk/circuit/config.go
@@ -57,10 +57,12 @@ func (conf *ZkCircuitConfig) KeySize() int {
 // or not. If it is not precalculated, it will calculate and initialise it. In
 // any case, the value is returned as big.Int.
 func (conf *ZkCircuitConfig) MaxCensusSize() *big.Int {
-	circuitMaxCensusSize := new(big.Int).Exp(big.NewInt(2), big.NewInt(int64(conf.Levels)), nil)
-	if conf.maxCensusSize == nil {
-		conf.maxCensusSize = circuitMaxCensusSize
+	if conf.maxCensusSize != nil {
+		return conf.maxCensusSize
 	}
+
+	circuitMaxCensusSize := new(big.Int).Exp(big.NewInt(2), big.NewInt(int64(conf.Levels)), nil)
+	conf.maxCensusSize = circuitMaxCensusSize
 	return circuitMaxCensusSize
 }
 
diff --git a/vochain/transaction/election_tx.go b/vochain/transaction/election_tx.go
index 0204182a2..7f85f30e6 100644
--- a/vochain/transaction/election_tx.go
+++ b/vochain/transaction/election_tx.go
@@ -59,17 +59,24 @@ func (t *TransactionHandler) NewProcessTxCheck(vtx *vochaintx.Tx) (*models.Proce
 	}
 
 	// check MaxCensusSize is properly set and within the allowed range
-	if tx.Process.GetMaxCensusSize() == 0 {
+	txMaxCensusSize := tx.Process.GetMaxCensusSize()
+	if txMaxCensusSize == 0 {
 		return nil, ethereum.Address{}, fmt.Errorf("maxCensusSize is zero")
 	}
 	maxProcessSize, err := t.state.MaxProcessSize()
 	if err != nil {
 		return nil, ethereum.Address{}, fmt.Errorf("cannot get maxProcessSize: %w", err)
 	}
-	if maxProcessSize > 0 && tx.Process.GetMaxCensusSize() > maxProcessSize {
+	if maxProcessSize > 0 && txMaxCensusSize > maxProcessSize {
 		return nil, ethereum.Address{},
 			fmt.Errorf("maxCensusSize is greater than the maximum allowed (%d)", maxProcessSize)
 	}
+	// check that the census size is not bigger than the circuit levels
+	if tx.Process.EnvelopeType.Anonymous && !t.ZkCircuit.Config.SupportsCensusSize(txMaxCensusSize) {
+		return nil, ethereum.Address{}, fmt.Errorf("maxCensusSize for anonymous envelope "+
+			"cannot be bigger than the number of levels of the circuit (max:%d provided:%d)",
+			t.ZkCircuit.Config.MaxCensusSize().Int64(), txMaxCensusSize)
+	}
 
 	// check signature
 	addr, acc, err := t.state.AccountFromSignature(vtx.SignedBody, vtx.Signature)
@@ -121,15 +128,6 @@ func (t *TransactionHandler) NewProcessTxCheck(vtx *vochaintx.Tx) (*models.Proce
 	}
 	tx.Process.ProcessId = pid.Marshal()
 
-	// if pre-register is enabled, check that the census size is not bigger than the circuit levels
-	if tx.Process.Mode.PreRegister && tx.Process.EnvelopeType.Anonymous {
-		if !t.ZkCircuit.Config.SupportsCensusSize(tx.Process.GetMaxCensusSize()) {
-			return nil, ethereum.Address{}, fmt.Errorf("maxCensusSize for anonymous envelope "+
-				"cannot be bigger than the number of levels of the circuit (%d)",
-				t.ZkCircuit.Config.Levels)
-		}
-	}
-
 	// TODO: Enable support for PreRegiser without Anonymous.  Figure out
 	// all the required changes to support a process with a rolling census
 	// that is not Anonymous.