Merge pull request ethereum#101 from zama-ai/petar/recover-verified-d…

…epths-for-precompile-calls

Recover verified depths for calls to precompiles

core/vm/contracts.go

@@ -239,7 +239,7 @@ func ActivePrecompiles(rules params.Rules) []common.Address {
 // - any error that occurred
 func RunPrecompiledContract(p PrecompiledContract, accessibleState PrecompileAccessibleState, caller common.Address, addr common.Address, input []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error) {
 	if accessibleState.Interpreter().evm.Commit {
-		accessibleState.Interpreter().evm.Logger.Info("Calling precompiled contract", "callerAddr", caller, "precompile", addr)
+		accessibleState.Interpreter().evm.Logger.Info("Calling precompile", "callerAddr", caller, "precompile", addr)
 	}
 	gasCost := p.RequiredGas(accessibleState, input)
 	if suppliedGas < gasCost {

core/vm/contracts_test.go

@@ -488,7 +488,7 @@ func FheAdd(t *testing.T, fheUintType fheUintType) {
 	}
 	decrypted := res.ciphertext.decrypt()
 	if decrypted.Uint64() != expected {
-		t.Fatalf("invalid decrypted result")
+		t.Fatalf("invalid decrypted result, decrypted %v != expected %v", decrypted.Uint64(), expected)
 	}
 }
 
@@ -525,7 +525,7 @@ func FheSub(t *testing.T, fheUintType fheUintType) {
 	}
 	decrypted := res.ciphertext.decrypt()
 	if decrypted.Uint64() != expected {
-		t.Fatalf("invalid decrypted result")
+		t.Fatalf("invalid decrypted result, decrypted %v != expected %v", decrypted.Uint64(), expected)
 	}
 }
 
@@ -562,7 +562,7 @@ func FheMul(t *testing.T, fheUintType fheUintType) {
 	}
 	decrypted := res.ciphertext.decrypt()
 	if decrypted.Uint64() != expected {
-		t.Fatalf("invalid decrypted result")
+		t.Fatalf("invalid decrypted result, decrypted %v != expected %v", decrypted.Uint64(), expected)
 	}
 }
 
@@ -600,7 +600,7 @@ func FheLte(t *testing.T, fheUintType fheUintType) {
 	}
 	decrypted := res.ciphertext.decrypt()
 	if decrypted.Uint64() != 0 {
-		t.Fatalf("invalid decrypted result")
+		t.Fatalf("invalid decrypted result, decrypted %v != expected %v", decrypted.Uint64(), 0)
 	}
 
 	// rhs <= lhs
@@ -615,7 +615,7 @@ func FheLte(t *testing.T, fheUintType fheUintType) {
 	}
 	decrypted = res.ciphertext.decrypt()
 	if decrypted.Uint64() != 1 {
-		t.Fatalf("invalid decrypted result")
+		t.Fatalf("invalid decrypted result, decrypted %v != expected %v", decrypted.Uint64(), 1)
 	}
 }
 
@@ -654,7 +654,7 @@ func FheLt(t *testing.T, fheUintType fheUintType) {
 	}
 	decrypted := res.ciphertext.decrypt()
 	if decrypted.Uint64() != 0 {
-		t.Fatalf("invalid decrypted result")
+		t.Fatalf("invalid decrypted result, decrypted %v != expected %v", decrypted.Uint64(), 0)
 	}
 
 	// rhs < lhs
@@ -669,7 +669,7 @@ func FheLt(t *testing.T, fheUintType fheUintType) {
 	}
 	decrypted = res.ciphertext.decrypt()
 	if decrypted.Uint64() != 1 {
-		t.Fatalf("invalid decrypted result")
+		t.Fatalf("invalid decrypted result, decrypted %v != expected %v", decrypted.Uint64(), 1)
 	}
 }
 
@@ -794,7 +794,7 @@ func TestCiphertextNotAutomaticallyDelegated(t *testing.T) {
 
 	ct := getVerifiedCiphertext(state, hash)
 	if ct != nil {
-		t.Fatalf("expected that ciphertext is not verified")
+		t.Fatalf("expected that ciphertext is not verified at depth (%d)", state.interpreter.evm.depth)
 	}
 }
 
@@ -806,18 +806,18 @@ func TestCiphertextVerificationConditions(t *testing.T) {
 	state.interpreter.evm.depth = verifiedDepth
 	ctPtr := getVerifiedCiphertext(state, hash)
 	if ctPtr == nil {
-		t.Fatalf("expected that ciphertext is verified at verifiedDepth")
+		t.Fatalf("expected that ciphertext is verified at verifiedDepth (%d)", verifiedDepth)
 	}
 
 	state.interpreter.evm.depth = verifiedDepth + 1
 	ct := getVerifiedCiphertext(state, hash)
 	if ct != nil {
-		t.Fatalf("expected that ciphertext is not verified at verifiedDepth + 1")
+		t.Fatalf("expected that ciphertext is not verified at verifiedDepth + 1 (%d)", verifiedDepth+1)
 	}
 
 	state.interpreter.evm.depth = verifiedDepth - 1
 	ct = getVerifiedCiphertext(state, hash)
 	if ct != nil {
-		t.Fatalf("expected that ciphertext is not verified at verifiedDepth - 1")
+		t.Fatalf("expected that ciphertext is not verified at verifiedDepth - 1 (%d)", verifiedDepth-1)
 	}
 }

core/vm/instructions.go

@@ -835,12 +835,22 @@ func opCreate2(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]
 }
 
 // If there are ciphertext handles in the arguments to a call, delegate them to the callee.
-func delegateCiphertextHandlesInArgs(interpreter *EVMInterpreter, args []byte) {
+// Return a map from ciphertext hash -> depthSet before delegation.
+func delegateCiphertextHandlesInArgs(interpreter *EVMInterpreter, args []byte) (verified map[common.Hash]*depthSet) {
+	verified = make(map[common.Hash]*depthSet)
 	for key, verifiedCiphertext := range interpreter.verifiedCiphertexts {
 		if contains(args, key.Bytes()) && isVerifiedAtCurrentDepth(interpreter, verifiedCiphertext) {
+			verified[key] = verifiedCiphertext.verifiedDepths.clone()
 			verifiedCiphertext.verifiedDepths.add(interpreter.evm.depth + 1)
 		}
 	}
+	return
+}
+
+func restoreVerifiedDepths(interpreter *EVMInterpreter, verified map[common.Hash]*depthSet) {
+	for k, v := range verified {
+		interpreter.verifiedCiphertexts[k].verifiedDepths = v
+	}
 }
 
 func opCall(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
@@ -867,15 +877,14 @@ func opCall(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byt
 		bigVal = value.ToBig()
 	}
 
-	delegateCiphertextHandlesInArgs(interpreter, args)
-
+	verifiedBefore := delegateCiphertextHandlesInArgs(interpreter, args)
 	ret, returnGas, err := interpreter.evm.Call(scope.Contract, toAddr, args, gas, bigVal)
-
 	if err != nil {
 		temp.Clear()
 	} else {
 		temp.SetOne()
 	}
+	restoreVerifiedDepths(interpreter, verifiedBefore)
 	stack.push(&temp)
 	if err == nil || err == ErrExecutionReverted {
 		ret = common.CopyBytes(ret)
@@ -906,14 +915,14 @@ func opCallCode(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([
 		bigVal = value.ToBig()
 	}
 
-	delegateCiphertextHandlesInArgs(interpreter, args)
-
+	verifiedBefore := delegateCiphertextHandlesInArgs(interpreter, args)
 	ret, returnGas, err := interpreter.evm.CallCode(scope.Contract, toAddr, args, gas, bigVal)
 	if err != nil {
 		temp.Clear()
 	} else {
 		temp.SetOne()
 	}
+	restoreVerifiedDepths(interpreter, verifiedBefore)
 	stack.push(&temp)
 	if err == nil || err == ErrExecutionReverted {
 		ret = common.CopyBytes(ret)
@@ -937,14 +946,14 @@ func opDelegateCall(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext
 	// Get arguments from the memory.
 	args := scope.Memory.GetPtr(int64(inOffset.Uint64()), int64(inSize.Uint64()))
 
-	delegateCiphertextHandlesInArgs(interpreter, args)
-
+	verifiedBefore := delegateCiphertextHandlesInArgs(interpreter, args)
 	ret, returnGas, err := interpreter.evm.DelegateCall(scope.Contract, toAddr, args, gas)
 	if err != nil {
 		temp.Clear()
 	} else {
 		temp.SetOne()
 	}
+	restoreVerifiedDepths(interpreter, verifiedBefore)
 	stack.push(&temp)
 	if err == nil || err == ErrExecutionReverted {
 		ret = common.CopyBytes(ret)
@@ -968,14 +977,14 @@ func opStaticCall(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext)
 	// Get arguments from the memory.
 	args := scope.Memory.GetPtr(int64(inOffset.Uint64()), int64(inSize.Uint64()))
 
-	delegateCiphertextHandlesInArgs(interpreter, args)
-
+	verifiedBefore := delegateCiphertextHandlesInArgs(interpreter, args)
 	ret, returnGas, err := interpreter.evm.StaticCall(scope.Contract, toAddr, args, gas)
 	if err != nil {
 		temp.Clear()
 	} else {
 		temp.SetOne()
 	}
+	restoreVerifiedDepths(interpreter, verifiedBefore)
 	stack.push(&temp)
 	if err == nil || err == ErrExecutionReverted {
 		ret = common.CopyBytes(ret)