You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
69 lines
1.4 KiB
Go
69 lines
1.4 KiB
Go
// Copyright (c) 2020, The Garble Authors.
|
|
// See LICENSE for licensing information.
|
|
|
|
package literals
|
|
|
|
import (
|
|
"fmt"
|
|
"go/ast"
|
|
"go/token"
|
|
mathrand "math/rand"
|
|
)
|
|
|
|
// obfuscator takes a byte slice and converts it to a ast.BlockStmt
|
|
type obfuscator interface {
|
|
obfuscate(obfRand *mathrand.Rand, data []byte) *ast.BlockStmt
|
|
}
|
|
|
|
// obfuscators contains all types which implement the obfuscator Interface
|
|
var obfuscators = []obfuscator{
|
|
simple{},
|
|
swap{},
|
|
split{},
|
|
shuffle{},
|
|
// seed{}, TODO: re-enable once https://go.dev/issue/47631 is fixed in Go 1.20
|
|
}
|
|
|
|
func genRandIntSlice(obfRand *mathrand.Rand, max, count int) []int {
|
|
indexes := make([]int, count)
|
|
for i := 0; i < count; i++ {
|
|
indexes[i] = obfRand.Intn(max)
|
|
}
|
|
return indexes
|
|
}
|
|
|
|
func randOperator(obfRand *mathrand.Rand) token.Token {
|
|
operatorTokens := [...]token.Token{token.XOR, token.ADD, token.SUB}
|
|
return operatorTokens[obfRand.Intn(len(operatorTokens))]
|
|
}
|
|
|
|
func evalOperator(t token.Token, x, y byte) byte {
|
|
switch t {
|
|
case token.XOR:
|
|
return x ^ y
|
|
case token.ADD:
|
|
return x + y
|
|
case token.SUB:
|
|
return x - y
|
|
default:
|
|
panic(fmt.Sprintf("unknown operator: %s", t))
|
|
}
|
|
}
|
|
|
|
func operatorToReversedBinaryExpr(t token.Token, x, y ast.Expr) *ast.BinaryExpr {
|
|
expr := &ast.BinaryExpr{X: x, Y: y}
|
|
|
|
switch t {
|
|
case token.XOR:
|
|
expr.Op = token.XOR
|
|
case token.ADD:
|
|
expr.Op = token.SUB
|
|
case token.SUB:
|
|
expr.Op = token.ADD
|
|
default:
|
|
panic(fmt.Sprintf("unknown operator: %s", t))
|
|
}
|
|
|
|
return expr
|
|
}
|