Android 中 SHA1 哈希实现的问题 [英] Issues with SHA1 hash implementation in Android

问题描述

我有两个用于计算 SHA1 的小片段.

I have two small snippets for calculating SHA1.

一个非常快但似乎不正确，另一个很慢但正确.
我认为将 FileInputStream 转换为 ByteArrayInputStream 是问题所在.

One is very fast but it seems that it isn't correct and the other is very slow but correct.
I think the FileInputStream conversion to ByteArrayInputStream is the problem.

快速版本:

MessageDigest md = MessageDigest.getInstance("SHA1");
FileInputStream fis = new FileInputStream("path/to/file.exe");
ByteArrayInputStream byteArrayInputStream =
    new ByteArrayInputStream(fis.toString().getBytes());
DigestInputStream dis = new DigestInputStream(byteArrayInputStream, md);
BufferedInputStream bis = new BufferedInputStream(fis);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();

int ch;
while ((ch = dis.read()) != -1) {
    byteArrayOutputStream.write(ch);
}

byte[] newInput = byteArrayOutputStream.toByteArray();
System.out.println("in digest : " +
    byteArray2Hex(dis.getMessageDigest().digest()));

byteArrayOutputStream = new ByteArrayOutputStream();
DigestOutputStream digestOutputStream =
    new DigestOutputStream(byteArrayOutputStream, md);
digestOutputStream.write(newInput);

System.out.println("out digest: " +
    byteArray2Hex(digestOutputStream.getMessageDigest().digest()));
System.out.println("length: " + 
    new String(
        byteArray2Hex(digestOutputStream.getMessageDigest().digest())).length());

digestOutputStream.close();
byteArrayOutputStream.close();
dis.close();

慢版:

MessageDigest algorithm = MessageDigest.getInstance("SHA1");
FileInputStream fis = new FileInputStream("path/to/file.exe");
BufferedInputStream bis = new BufferedInputStream(fis);
DigestInputStream   dis = new DigestInputStream(bis, algorithm);

// read the file and update the hash calculation
while (dis.read() != -1);

 // get the hash value as byte array
byte[] hash = algorithm.digest();

转换方法:

private static String byteArray2Hex(byte[] hash) {
    Formatter formatter = new Formatter();
    for (byte b : hash) {
        formatter.format("%02x", b);
    }
    return formatter.toString();
}

我希望有另一种可能让它运行，因为我需要性能.

I hope there is another possibility to get it running because I need the performance.

推荐答案

我使用了一个用 JNI 加载的高性能 C++ 实现.
欲了解更多详情，请发表评论.

I used a high performance c++ implementation which I load with JNI.
For more details write a comment, please.

JNI 的要求是 Android NDK.对于 Windows，还需要 cygwin 或类似的东西.
如果你决定使用 cygwin，我会给你一些关于如何让它与 NDK 一起工作的小说明:

Requirements for JNI is the Android NDK. For Windows is needed in addition cygwin or something similar.
If you decided for cygwin, I give you some little instructions how to get it working with the NDK:

1. 从 cygwin 下载 setup.exe 并执行它.
2. 点击下一步并选择从互联网安装确认下一步.
3. 接下来的两个步骤根据需要调整设置，并一如既往地单击下一步.
4. 选择您的互联网连接以及与最后阶段相同的过程.
5. 下载页面会吸引眼球，请选择它或仅获取您所在国家/地区的下载页面.没什么好说的了.
6. 我们需要make 和gcc-g++ 包.您可以使用左上角的搜索找到它们，点击跳过，直到显示一个版本并选择第一个字段.选择之后，我们总是这样做.
7. 您将获得信息，即存在必须解决的依赖项.通常不需要自己做并确认.
8. 下载和安装开始.
9. 如果需要，您可以创建快捷方式，否则请点击特殊的完成.
10. 下载 zip 文件并将 NDK 解压缩到不包含空格的路径.
11. 您现在可以开始使用 cygwin.
12. 导航到 NDK.路径 /cydrive 为您提供所有可用的驱动器 f.e.cd/cygdrive/d 导航到带有字母 D 的驱动器.
13. 在 NDK 的根文件夹中，您可以使用 ./ndk-build 执行文件 ndk-build.应该会出现Android NDK:Could not find application project directory !之类的错误.
    您必须在 Android 项目中导航才能执行该命令.那么让我们从一个项目开始吧.

1. Download the setup.exe from cygwin and execute it.
2. Click on Next and choice Install from Internet confirm with Next.
3. The next two steps adjust the settings as desired and as always click Next.
4. Select your internet connection and the same procedure as in the final stages.
5. A download page will catch the eye select it or take just a download page, which is in your country. There is nothing more to say.
6. We need the packages make and gcc-g++. You can find them using the search in the left upper corner, click on the Skip til a version is displayed and the first field is selected. Do that what we have always done after a selection.
7. You will get the information, that there are dependencies, which must be resolved. It is usually not necessary to do it yourself and confirm it.
8. The download and installation started.
9. If you need you can create shortcuts otherwise click on exceptional Finish.
10. Download the zip file and extract the NDK to a non space containing path.
11. You can start now cygwin.
12. Navigate to the NDK. The path /cydrive gives you all available drives f.e. cd /cygdrive/d navigates to the drive with the letter D.
13. In the root folder of the NDK you can execute the file ndk-build with ./ndk-build. There should be an error occurs like Android NDK: Could not find application project directory !.
    You have to navigate in an Android project to execute the command. So let's start with a project.

在我们开始项目之前，搜索哈希算法的 C/C++ 实现.我从这个网站CSHA1获取了代码.
您应该根据您的要求编辑源代码.

Before we can start with the project search for a C/C++ implementation of the hash algorithm. I took the code from this site CSHA1.
You should edit the source code for your requirements.

现在我们可以从 JNI 开始.
您在 Android 项目中创建了一个名为 jni 的文件夹.它包含所有本机源文件和 Android.mk(稍后会详细介绍该文件).
将您下载(和编辑)的源文件复制到该文件夹​​中.

Now we can start with JNI.
You create a folder called jni in your Android project. It contains all native source files and the Android.mk (more about that file later), too.
Copy your downloaded (and edited) source files in that folder.

我的 java 包名为 de.dhbw.file.sha1，因此我将源文件命名为类似的名称，以便于查找.

My java package is called de.dhbw.file.sha1, so I named my source files similar to find them easily.

Android.mk:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_LDLIBS := -llog

# How the lib is called?
LOCAL_MODULE    := SHA1Calc
# Which is your main SOURCE(!) file?
LOCAL_SRC_FILES := de_dhbw_file_sha1_SHA1Calc.cpp

include $(BUILD_SHARED_LIBRARY)

Java 代码:
我使用 AsyncTask 和 ProgressDialog 来向用户提供有关操作的一些反馈.

Java code:
I used the AsyncTask with a ProgressDialog to give the user some feedback about the action.

package de.dhbw.file.sha1;

// TODO: Add imports

public class SHA1HashFileAsyncTask extends AsyncTask<String, Integer, String> {
    // [...]

    static {
        // loads a native library
        System.loadLibrary("SHA1Calc");
    }

    // [...]

    // native is the indicator for native written methods
    protected native void calcFileSha1(String filePath);

    protected native int getProgress();

    protected native void unlockMutex();

    protected native String getHash();

    // [...]
}

本机代码(C++):

记住访问本机代码中的变量或使用线程的其他方式需要同步，否则您很快就会遇到分段错误！

对于 JNI 用法，您必须添加 #include .

For JNI usage you have to add #include <jni.h>.

对于记录插入以下包括#include .
现在您可以使用 __android_log_print(ANDROID_LOG_DEBUG, DEBUG_TAG, "Version [%s]", "19"); 登录.
第一个参数是消息的类型，第二个参数是导致库.
你可以看到我的代码中有一个版本号.这非常有用，因为有时 apk 构建器不使用新的本机库.如果在线版本错误，则可以极大地缩短故障排除时间.

For logging insert following include #include <android/log.h>.
Now you can log with __android_log_print(ANDROID_LOG_DEBUG, DEBUG_TAG, "Version [%s]", "19");.
The first argument is the type of message and the second the causing library.
You can see I had a version number in my code. It is very helpful because sometimes the apk builder doesn't use the new native libraries. Troubleshooting can be extremely shortened, if the wrong version is online.

原生代码中的命名约定有点疯狂:Java_[包名]_[类名]_[方法名].

The naming conventions in the native code are a little bit crasier: Java_[package name]_[class name]_[method name].

始终给出第一个参数，但您应该根据应用程序区分:

The first to arguments are always given, but depending on the application you should distinguish:

• func(JNIEnv * env, jobject jobj) -> JNI 调用是一个实例方法
• func(JNIEnv * env, jclass jclazz) -> JNI 调用是静态方法

• func(JNIEnv * env, jobject jobj) -> JNI call is an instance method
• func(JNIEnv * env, jclass jclazz) -> JNI call is a static method

方法的头文件calcFileSha1(...):
JNIEXPORT void JNICALL Java_de_dhbw_file_sha1_SHA1HashFileAsyncTask_calcFileSha1(JNIEnv * env, jobject jobj, jstring file)

JDK 提供二进制 javah.exe，它生成本机代码的头文件.用法很简单，直接用全限定类调用即可:
javah de.dhbw.file.sha1.SHA1HashFileAsyncTask

The JDK delivers the binary javah.exe, which generates the header file for the native code. The usage is very simple, simply call it with the full qualified class:
javah de.dhbw.file.sha1.SHA1HashFileAsyncTask

就我而言，我必须另外提供 bootclasspath，因为我使用 Android 类:javah -bootclasspath de.dhbw.file.sha1.SHA1HashFileAsyncTask

In my case I have to give the bootclasspath additionally, because I use Android classes: javah -bootclasspath <path_to_the_used_android_api> de.dhbw.file.sha1.SHA1HashFileAsyncTask

这将是生成的文件:

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class de_dhbw_file_sha1_SHA1HashFileAsyncTask */

#ifndef _Included_de_dhbw_file_sha1_SHA1HashFileAsyncTask
#define _Included_de_dhbw_file_sha1_SHA1HashFileAsyncTask
#ifdef __cplusplus
extern "C" {
#endif
#undef de_dhbw_file_sha1_SHA1HashFileAsyncTask_ERROR_CODE
#define de_dhbw_file_sha1_SHA1HashFileAsyncTask_ERROR_CODE -1L
#undef de_dhbw_file_sha1_SHA1HashFileAsyncTask_PROGRESS_CODE
#define de_dhbw_file_sha1_SHA1HashFileAsyncTask_PROGRESS_CODE 1L
/*
 * Class:     de_dhbw_file_sha1_SHA1HashFileAsyncTask
 * Method:    calcFileSha1
 * Signature: (Ljava/lang/String;)V
 */
JNIEXPORT void JNICALL Java_de_dhbw_file_sha1_SHA1HashFileAsyncTask_calcFileSha1
  (JNIEnv *, jobject, jstring);

/*
 * Class:     de_dhbw_file_sha1_SHA1HashFileAsyncTask
 * Method:    getProgress
 * Signature: ()I
 */
JNIEXPORT jint JNICALL Java_de_dhbw_file_sha1_SHA1HashFileAsyncTask_getProgress
  (JNIEnv *, jobject);

/*
 * Class:     de_dhbw_file_sha1_SHA1HashFileAsyncTask
 * Method:    unlockMutex
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_de_dhbw_file_sha1_SHA1HashFileAsyncTask_unlockMutex
  (JNIEnv *, jobject);

/*
 * Class:     de_dhbw_file_sha1_SHA1HashFileAsyncTask
 * Method:    getHash
 * Signature: ()Ljava/lang/String;
 */
JNIEXPORT jstring JNICALL Java_de_dhbw_file_sha1_SHA1HashFileAsyncTask_getHash
  (JNIEnv *, jobject);

#ifdef __cplusplus
}
#endif
#endif

您可以更改文件，恕不另行通知.但是不要再次使用javah！

类和方法
要获取类实例，您可以使用 jclass clz = callEnv->FindClass(CALL_CLASS);.在这种情况下，CALL_CLASS 是类 de/dhbw/file/sha1/SHA1HashFileAsyncTask 的完整限定路径.

Class and methods
To get a class instance you can use jclass clz = callEnv->FindClass(CALL_CLASS);. In this case is CALL_CLASS the full qualified path to the class de/dhbw/file/sha1/SHA1HashFileAsyncTask.

要查找需要 JNIEnv 和类的实例的方法:
jmethodID midSet = callEnv->GetMethodID(callClass, "setFileSize", "(J)V");第一个参数是类的实例，第二个是方法的名称，第三个是方法的签名.
您可以使用来自 JDK 的给定二进制 javap.exe 获得的签名.只需使用类 f.e. 的完全限定路径调用它.javap -s de.dhbw.file.sha1.SHA1HashFileAsyncTask.
你会得到这样的结果:

To find a method you need the JNIEnv and an instance of the class:
jmethodID midSet = callEnv->GetMethodID(callClass, "setFileSize", "(J)V"); The first argument is the instance of the class, the second the name of the method and the third is the signature of the method.
The signature you can get with the from JDK given binary javap.exe. Simply call it with the full qualified path of the class f.e. javap -s de.dhbw.file.sha1.SHA1HashFileAsyncTask.
You will get an result like:

Compiled from "SHA1HashFileAsyncTask.java"
public class de.dhbw.file.sha1.SHA1HashFileAsyncTask extends android.os.AsyncTas
k<java.lang.String, java.lang.Integer, java.lang.String> {
  [...]
  static {};
    Signature: ()V

  public de.dhbw.file.sha1.SHA1HashFileAsyncTask(android.content.Context, de.dhb
w.file.sha1.SHA1HashFileAsyncTask$SHA1AsyncTaskListener);
    Signature: (Landroid/content/Context;Lde/dhbw/file/sha1/SHA1HashFileAsyncTas
k$SHA1AsyncTaskListener;)V

  protected native void calcFileSha1(java.lang.String);
    Signature: (Ljava/lang/String;)V

  protected native int getProgress();
    Signature: ()I

  protected native void unlockMutex();
    Signature: ()V

  protected native java.lang.String getHash();
    Signature: ()Ljava/lang/String;

  [...]

  public void setFileSize(long);
    Signature: (J)V

  [...]
}

如果找到方法，则变量不等于 0.
调用方法很简单:

If the method is found the variable is not equal 0.
Calling the method is very easy:

callEnv->CallVoidMethod(callObj, midSet, size);

第一个参数是来自main"方法的给定 jobject，我认为其他参数很清楚.

The first argument is the given jobject from the "main" method and I think the others are clear.

请记住，虽然类的私有方法，但您可以从本机代码调用，因为本机代码是其中的一部分！

字符串
将使用以下代码转换给定的字符串:

Strings
The given string would be converted with following code:

jboolean jbol;
const char *fileName = env->GetStringUTFChars(file, &jbol);

另一种方式:

TCHAR* szReport = new TCHAR;
jstring result = callEnv->NewStringUTF(szReport);

它可以是每个 char* 变量.

It can be every char* variable.

例外
可以用 JNIEnv 抛出:

callEnv->ThrowNew(callEnv->FindClass("java/lang/Exception"), 
    "Hash generation failed");

您还可以使用 JNIEnv 检查是否发生了异常:

You can also check if there is an exception occurred also with JNIEnv:

if (callEnv->ExceptionOccurred()) {
    callEnv->ExceptionDescribe();
    callEnv->ExceptionClear();
}

规格

• Java 本机接口规范

构建/清理

构建
在我们创建了所有文件并用内容填充它们之后，我们就可以构建它了.
打开 cygwin，导航到项目根目录并从那里执行 ndk-build，它位于 NDK 根目录中.
开始编译，如果成功你会得到这样的输出:

Build
After we have created all files and filled them with content, we can build it.
Open cygwin, navigate to the project root and execute from there the ndk-build, which is in the NDK root.
This start the compile, if it is success you will get an output like that:

$ /cygdrive/d/android-ndk-r5c/ndk-build
Compile++ thumb  : SHA1Calc <= SHA1Calc.cpp
SharedLibrary  : libSHA1Calc.so
Install        : libSHA1Calc.so => libs/armeabi/libSHA1Calc.so

如果有任何错误，您将获得编译器的典型输出.

If there is any error, you will get the typical output from the compiler.

干净
打开cygwin，切换到你的Android项目并执行命令/cygdrive/d/android-ndk-r5c/ndk-build clean.

构建 apk
构建本机库后，您可以构建项目.我发现很干净，使用 Eclipse 功能 clean project 是有利的.

调试
java代码的调试和以前一样.
C++代码的调试会在下一次进行.

Debugging
Debugging of java code isn't different as before.
The debugging of c++ code will follow in the next time.

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