Expression Obfuscation
Obfuscate expressions appearing in code to increase reverse engineering difficulty.
Supported Expression Types
- Basic calculation expressions: add, sub, mul, div, neg
- Basic bitwise calculation expressions: and, or, xor, not
- Left shift or right shift calculation expressions: shl, shr
Supported Constant Types
- int, uint
- long, ulong
- float
- double
Settings
ObfuzSettings.ExprObfusSettings contains constant encryption related settings, detailed documentation can be found in Configuration.
Rule Files
By default, Obfuz encrypts all function calls, but also supports rule files to finely control the scope and effects of constant encryption. The ExprObfusSettings.RuleFiles option can configure 0-N rule files.
Rule file relative paths are from the project directory, valid rule file paths look like: Assets/XXX/YYY.xml.
Configuration example:
<?xml version="1.0" encoding="UTF-8"?>
<obfuz>
<global obfuscationLevel="Basic" obfuscationPercentage="0.3">
</global>
<assembly name="Obfus2">
<type name="*.TestNotObfusAnyMethods" obfuscationLevel="None"/>
<type name="*.TestObfusAll" obfuscationLevel="Advanced"/>
<type name="*.TestObfusSomeMethods" >
<method name="Foo" obfuscationLevel="MostAdvanced"/>
</type>
</assembly>
</obfuz>
- Top-level tag must be obfuz
- Second-level tags can be global and assembly
global
Global defines global default encryption parameters.
| Attribute | Nullable | Default | Description |
|---|---|---|---|
| obfuscationLevel | Yes | None | Obfuscation level, can take values None, Basic, Advanced, MostAdvanced |
| obfuscationPercentage | Yes | 0.5 | Obfuscation probability. Value range [0 - 1] |
assembly
| Attribute | Nullable | Default | Description |
|---|---|---|---|
| name | No | Assembly name, must be in the obfuscated assembly list | |
| Others | Yes | Inherit same-named options from global | All options in global can be used, if not defined, inherit the value of same-named option in global |
Assembly's child elements can only be type.
type
| Attribute | Nullable | Default | Description |
|---|---|---|---|
| name | No | Type name wildcard string, if empty means match all types | |
| Others | Yes | Inherit same-named options from assembly | All options in global can be used, if not defined, inherit the value of same-named option in assembly |
Since function calls can only appear in function code, type's child elements can only be method.
method
| Attribute | Nullable | Default | Description |
|---|---|---|---|
| name | No | Type name wildcard string, if empty means match all types | |
| Others | Yes | Inherit same-named options from assembly | All options in global can be used, if not defined, inherit the value of same-named option in assembly |