做自己的Android ROM,屏蔽对framework中的系统APK的签名检查 - 风言枫语

时间:2024-03-05 09:00:14

最近两天一直在尝试更新Android中的关键库以达到定制ROM的效果,中间比较曲折,记录下来供自己和大家参考。


因为我需要基于Android的原生代码做一定的修改,所以如果无法将我自己编译出的APK或Jar替换系统中的东西,则无法达成我的目标。

我的测试的机器:htc one 电信定制版(802d),Android版本:4.2.2;LG Nexus 4,Android版本:4.3。

测试第一步:

    将手机root掉,以替换修改系统文件的权限。不同厂商的手机的root步骤不一样,自己上网搜索吧。

测试第二步:

   使用我自己编译出来的SystemUI.apk,替换Nexus 4的SystemUI.apk,通过 adb logcat > 1.txt 查看日志,直接报下面的错;

W/PackageManager(  530): Signature mismatch for shared user : SharedUserSetting{41ea0bc8 android.uid.system/1000}

E/PackageManager(  530): Package com.android.systemui has no signatures that match those in shared user android.uid.system; ignoring!

  签名有问题,根据这个关键字“has no signatures that match those” 去搜索Android源代码,可以在PackageManagerService.java中找到如下函数:

    private boolean verifySignaturesLP(PackageSetting pkgSetting,
            PackageParser.Package pkg) {
        if (pkgSetting.signatures.mSignatures != null) {
            // Already existing package. Make sure signatures match
            if (compareSignatures(pkgSetting.signatures.mSignatures, pkg.mSignatures) !=
                PackageManager.SIGNATURE_MATCH) {
                    Slog.e(TAG, "Package " + pkg.packageName
                            + " signatures do not match the previously installed version; ignoring!");
                    mLastScanError = PackageManager.INSTALL_FAILED_UPDATE_INCOMPATIBLE;
                    return false;
                }
        }
        // Check for shared user signatures
        if (pkgSetting.sharedUser != null && pkgSetting.sharedUser.signatures.mSignatures != null) {
            if (compareSignatures(pkgSetting.sharedUser.signatures.mSignatures,
                    pkg.mSignatures) != PackageManager.SIGNATURE_MATCH) {
                Slog.e(TAG, "Package " + pkg.packageName
                        + " has no signatures that match those in shared user "
                        + pkgSetting.sharedUser.name + "; ignoring!");
                mLastScanError = PackageManager.INSTALL_FAILED_SHARED_USER_INCOMPATIBLE;
                return false;
            }
        }
        return true;
    }

  直接替换,肯定是不行了,签名通不过,那我可否尝试将签名检查的代码给屏蔽掉?


测试第三步:

  尝试屏蔽对系统级APK的签名检查,代码已经找到,在这个目录下:frameworks/base/services/java/com/android/server/pm。

  进一步分析,services目录下的内容,最终会被编译成 services.jar,adb shell 后,在 /system/framework 下可以找到 services.jar。

root@android:/system/framework # ls servi*
ls servi*
services.jar

在 out/target/product/generic/dex_bootjars/system/framework 这个目录下可以找到 services.jar,

直接使用自己编译出来的services.jar去替换 /system/framework下的同名jar包,重启os后,好像报的这个错误:DexOpt: mismatch dep signature

然后os一直处于死循环中,无法开机成功。

根据“DexOpt: mismatch dep signature”这个关键字搜索,在DexPrepare.cpp中有对应的检查:

if (memcmp(signature, ptr, kSHA1DigestLen) != 0) {  
    LOGI("DexOpt: mismatch dep signature for \'%s\'", cacheFileName);  
    goto bail;  
}  


测试第四步:

  既然第三步也不行,那我用自己编译出来的“libdvm.so” 将/system/lib下的同名文件更新掉,重启os后,还是类似的错误,签名摘要校验不过。

 

当前陷入了短时间的僵局,上网找了很多资料参考,大部分仅能参考,写得太不详细,直接我遇到了这个文档:《MIUI ROM定制教程》,

已经在我的百度网盘共享: http://pan.baidu.com/share/link?shareid=198381908&uk=4145338314

神一般的文档,将Android的系统框架,到刷机原理,再到一些刷机的具体细节,都写得非常清楚。

 

下面的过程是基于HTC ONE(802d)来测试的:

1、先找一个可刷机的ROM,我找到的是Nic_One_M7_802d_4.2.2_Devil_3.5_signed.zip,这个包可以刷机成功并且系统可用。

之前找的两个包可以刷机成功,但屏幕驱动似乎有问题,触屏无反应。

2、将原有包中的services.jar转成smali文件,通过 baksmali-1.4.2.jar 进行将 jar中的dex文件转成smali文件,将PackageManagerService.smali中的verifySignaturesLP函数的实现给修改掉,然后再使用smali-1.4.2.jar将反编译出的包含smali文件的目录转成dex文件,使用winrar打开services.jar,将新生成的classes.dex覆盖jar包中的classes.dex,将这个新jar包替换原ROM zip包中的同名文件。

再使用“土豆ROM工具箱” 将新ROM zip包重新签名下,再进行刷机。

经过几分钟的等待后,系统可用,并且使用我自己编译出的 SystemUI.apk 直接覆盖 /system/framework/ 下的同名文件,也不会再报签名错误,只是无法正常运行。

为了进一步验证,我将系统的 SystemUI.apk 复制我的电脑上,使用“土豆ROM工具箱”将其重新签名,然后再替换原生 SystemUI.apk,HTC手机也是可以正常运行的。

终于成功将系统APK签名验证这步给屏蔽了,这样我就可以基于此ROM做很多其它想做的事件了。

 

smali-1.4.2.jar、baksmali-1.4.2.jar的使用命令参考:

C:\Users\zhao3546\Desktop\Android\Android_framework_4.2>java -jar smali-1.4.2.jar -h
usage: java -jar smali.jar [options] [--] [<smali-file>|folder]*
assembles a set of smali files into a dex file
 -?,--help                      prints the help message then exits. Specify
                                twice for debug options
 -a,--api-level <API_LEVEL>     The numeric api-level of the file to generate,
                                e.g. 14 for ICS. If not specified, it defaults
                                to 14 (ICS).
 -o,--output <FILE>             the name of the dex file that will be written.
                                The default is out.dex
 -v,--version                   prints the version then exits
 -x,--allow-odex-instructions   allow odex instructions to be compiled into the
                                dex file. Only a few instructions are supported
                                - the ones that can exist in a dead code path
                                and not cause dalvik to reject the class


C:\Users\zhao3546\Desktop\Android\Android_framework_4.2>java -jar baksmali-1.4.2.jar -h
usage: java -jar baksmali.jar [options] <dex-file>
disassembles and/or dumps a dex file
 -?,--help                                  prints the help message then exits.
                                            Specify twice for debug options
 -a,--api-level <API_LEVEL>                 The numeric api-level of the file
                                            being disassembled. If not
                                            specified, it defaults to 14 (ICS).
 -b,--no-debug-info                         don\'t write out debug info (.local,
                                            .param, .line, etc.)
 -c,--bootclasspath <BOOTCLASSPATH>         the bootclasspath jars to use, for
                                            analysis. Defaults to
                                            core.jar:ext.jar:framework.jar:andro
                                            id.policy.jar:services.jar. If the
                                            value begins with a :, it will be
                                            appended to the default
                                            bootclasspath instead of replacing
                                            it
 -d,--bootclasspath-dir <DIR>               the base folder to look for the
                                            bootclasspath files in. Defaults to
                                            the current directory
 -f,--code-offsets                          add comments to the disassembly
                                            containing the code offset for each
                                            address
 -l,--use-locals                            output the .locals directive with
                                            the number of non-parameter
                                            registers, rather than the .register
                                            directive with the total number of
                                            register
 -m,--no-accessor-comments                  don\'t output helper comments for
                                            synthetic accessors
 -o,--output <DIR>                          the directory where the disassembled
                                            files will be placed. The default is
                                            out
 -p,--no-parameter-registers                use the v<n> syntax instead of the
                                            p<n> syntax for registers mapped to
                                            method parameters
 -r,--register-info <REGISTER_INFO_TYPES>   print the specificed type(s) of
                                            register information for each
                                            instruction. "ARGS,DEST" is the
                                            default if no types are specified.
                                            Valid values are:
                                            ALL: all pre- and post-instruction
                                            registers.
                                            ALLPRE: all pre-instruction
                                            registers
                                            ALLPOST: all post-instruction
                                            registers
                                            ARGS: any pre-instruction registers
                                            used as arguments to the instruction
                                            DEST: the post-instruction
                                            destination register, if any
                                            MERGE: Any pre-instruction register
                                            has been merged from more than 1
                                            different post-instruction register
                                            from its predecessors
                                            FULLMERGE: For each register that
                                            would be printed by MERGE, also show
                                            the incoming register types that
                                            were merged
 -s,--sequential-labels                     create label names using a
                                            sequential numbering scheme per
                                            label type, rather than using the
                                            bytecode address
 -v,--version                               prints the version then exits
 -x,--deodex                                deodex the given odex file. This
                                            option is ignored if the input file
                                            is not an odex file


 

 

posted on 2013-09-04 19:06  风言枫语  阅读(3000)  评论(0编辑  收藏  举报