Android安全–加强版Smali Log注入

有的时候我们需要注入smali调用Log输出，打印字符串的值。

比如说：

如果我们要打印下面v1的值。

new-instance v1, Ljava/lang/String;

const-string v7, “this is my string”

invoke-direct {v1, v7}, Ljava/lang/String;-><init>(Ljava/lang/String;)V

那可能要先修改使用的寄存器数，然后添加打印：

这样注入是比较麻烦的，可以自己建一个crack.smali文件，并定义自己的Log信息输出函数，如下：

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.class public Lcrack;
.super Ljava/lang/Object;
.source "crack.java"

.method public static log1(Ljava/lang/String;)V #打印出info 1字符串
.locals 1
.prologue

const-string v0, "info 1"
invoke-static {v0, p0}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I
return-void
.end method

.method public static log2(Ljava/lang/String;)V #打印出info 2字符串
.locals 1
.prologue

const-string v0, "info 2"
invoke-static {v0, p0}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I
return-void
.end method

.method public static log3(Ljava/lang/String;)V #打印出info 3字符串
.locals 1
.prologue

const-string v0, "info 3"
invoke-static {v0, p0}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I
return-void
.end method

.method public static I(I)V #打印出int型值
.locals 2

.prologue

const-string v0, "info_int"

invoke-static {p0}, Ljava/lang/String;->valueOf(I)Ljava/lang/String;

move-result-object v1

invoke-static {v0, v1}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I

return-void
.end method

.method public static J(J)V #打印出long类型的值
.locals 2

.prologue

const-string v0, "info_long"

invoke-static {p0, p1}, Ljava/lang/String;->valueOf(J)Ljava/lang/String;

move-result-object v1

invoke-static {v0, v1}, Landroid/util/Log;->d(Ljava/lang/String;Ljava/lang/String;)I

return-void
.end method

这个时候就只需要添加一行代码就行了：

invoke-static {v1}, Lcrack;->log1(Ljava/lang/String;)V

就能打印出：