Merge pull request #2910 from onflow/supun/port-revertible-random

[v0.42] Port adding new `revertibleRandom` function

runtime/common/computationkind.go

@@ -133,7 +133,7 @@ const (
 	//
 	ComputationKindSTDLIBPanic
 	ComputationKindSTDLIBAssert
-	ComputationKindSTDLIBUnsafeRandom
+	ComputationKindSTDLIBRevertibleRandom
 	_
 	_
 	_

runtime/environment.go

@@ -127,7 +127,7 @@ type interpreterEnvironment struct {
 
 var _ Environment = &interpreterEnvironment{}
 var _ stdlib.Logger = &interpreterEnvironment{}
-var _ stdlib.UnsafeRandomGenerator = &interpreterEnvironment{}
+var _ stdlib.RandomGenerator = &interpreterEnvironment{}
 var _ stdlib.BlockAtHeightProvider = &interpreterEnvironment{}
 var _ stdlib.CurrentBlockProvider = &interpreterEnvironment{}
 var _ stdlib.PublicAccountHandler = &interpreterEnvironment{}

runtime/runtime_test.go

@@ -4734,7 +4734,7 @@ func TestRuntimeBlock(t *testing.T) {
 	)
 }
 
-func TestRuntimeUnsafeRandom(t *testing.T) {
+func TestRuntimeRandom(t *testing.T) {
 
 	t.Parallel()
 
@@ -4743,8 +4743,10 @@ func TestRuntimeUnsafeRandom(t *testing.T) {
 	script := []byte(`
       transaction {
         prepare() {
-          let rand = unsafeRandom()
-          log(rand)
+          let rand1 = revertibleRandom()
+          log(rand1)
+          let rand2 = unsafeRandom()
+          log(rand2)
         }
       }
     `)
@@ -4777,6 +4779,7 @@ func TestRuntimeUnsafeRandom(t *testing.T) {
 	assert.Equal(t,
 		[]string{
 			"7558174677681708339",
+			"7558174677681708339",
 		},
 		loggedMessages,
 	)

runtime/stdlib/builtin.go

@@ -20,7 +20,7 @@ package stdlib
 
 type StandardLibraryHandler interface {
 	Logger
-	UnsafeRandomGenerator
+	RandomGenerator
 	BlockAtHeightProvider
 	CurrentBlockProvider
 	PublicAccountHandler
@@ -40,6 +40,7 @@ func DefaultStandardLibraryValues(handler StandardLibraryHandler) []StandardLibr
 		SignatureAlgorithmConstructor,
 		RLPContract,
 		NewLogFunction(handler),
+		NewRevertibleRandomFunction(handler),
 		NewUnsafeRandomFunction(handler),
 		NewGetBlockFunction(handler),
 		NewGetCurrentBlockFunction(handler),

runtime/stdlib/random.go

@@ -26,26 +26,64 @@ import (
 	"github.com/onflow/cadence/runtime/sema"
 )
 
-const unsafeRandomFunctionDocString = `
+const revertibleRandomFunctionDocString = `
 Returns a pseudo-random number.
 
 NOTE: The use of this function is unsafe if not used correctly.
 
 Follow best practices to prevent security issues when using this function
 `
 
-var unsafeRandomFunctionType = &sema.FunctionType{
+var revertibleRandomFunctionType = &sema.FunctionType{
 	ReturnTypeAnnotation: sema.NewTypeAnnotation(
 		sema.UInt64Type,
 	),
 }
 
-type UnsafeRandomGenerator interface {
+type RandomGenerator interface {
 	// ReadRandom reads pseudo-random bytes into the input slice, using distributed randomness.
 	ReadRandom([]byte) error
 }
 
-func NewUnsafeRandomFunction(generator UnsafeRandomGenerator) StandardLibraryValue {
+func NewRevertibleRandomFunction(generator RandomGenerator) StandardLibraryValue {
+	return NewStandardLibraryFunction(
+		"revertibleRandom",
+		revertibleRandomFunctionType,
+		revertibleRandomFunctionDocString,
+		func(invocation interpreter.Invocation) interpreter.Value {
+			return interpreter.NewUInt64Value(
+				invocation.Interpreter,
+				func() uint64 {
+					var buffer [8]byte
+					var err error
+					errors.WrapPanic(func() {
+						err = generator.ReadRandom(buffer[:])
+					})
+					if err != nil {
+						panic(interpreter.WrappedExternalError(err))
+					}
+					return binary.LittleEndian.Uint64(buffer[:])
+				},
+			)
+		},
+	)
+}
+
+// `unsafeRandom` related constants and functions will be deleted
+// when the function is deprecated
+const unsafeRandomFunctionDocString = `
+Deprecated: Use revertibleRandom instead.
+
+Returns a pseudo-random number.
+
+NOTE: The use of this function is unsafe if not used correctly.
+
+Follow best practices to prevent security issues when using this function
+`
+
+var unsafeRandomFunctionType = revertibleRandomFunctionType
+
+func NewUnsafeRandomFunction(generator RandomGenerator) StandardLibraryValue {
 	return NewStandardLibraryFunction(
 		"unsafeRandom",
 		unsafeRandomFunctionType,