安全加密C语言库OpenSSL&＃xff0c;在Android中服务器和客户端之间的签名验证和数据加密通信等。
OpenSSL系列文章&＃xff1a;
一、Android CMake轻松实现基于OpenSSL的HmacSHA1签名
二、Android CMake轻松实现基于OpenSSL的SHA(1-512)签名
三、Android CMake轻松实现基于OpenSSL的MD5信息摘要&异或加解密
四、Android CMake轻松实现基于OpenSSL的AES加解密
五、Android CMake轻松实现基于OpenSSL的RSA加解密
六、Android CMake轻松实现基于OpenSSL的RSA签名和验证
七、在Retrofit的基础上结合OpenSSL实现服务器和客户端之间数据加密通信
最近有这么一个需求&＃xff0c;要对接口进行签名验证以防止被刷。开始想到了在Java中实现HmacSHA1签名&＃xff0c;但由于Java代码较容易反编译直接获取秘钥&＃xff0c;而否定了这个方案。为了解决这个问题&＃xff0c;把实现签名的逻辑代码用C/C&＃43;&＃43;来编写&＃xff0c;编译成xxx.so库&＃xff0c;大大提高了反编译的门槛&＃xff0c;从而降低了被反编译的风险。
在C/C&＃43;&＃43;中要实现HmacSHA1签名&＃xff0c;只有依赖一个很出名的C语言中常用的加解密库OpenSSL。什么是OpenSSL请自行百度&＃xff0c;随便搜都是一大堆。难点在于在Android中进行Jni开发&＃xff0c;在C/C&＃43;&＃43;文件中要调用第三方OpenSSL的xxx.so库&＃xff0c;那怎样才能把OpenSSL的xxx.so库引入我们的C/C&＃43;&＃43;文件中呢&＃xff1f;换句话说就是最终我们的C/C&＃43;&＃43;文件会被编译成一个.so库&＃xff0c;就叫libsignature.so吧&＃xff01;而这个库又引用了第三方xxx.so库。不过不用担心&＃xff0c;自从Android支持CMake后&＃xff0c;一切都变得简单了。网络上也有很多博客&＃xff0c;也有很多代码片段&＃xff0c;但是对于初学者来说&＃xff0c;根本不知道那是什么玩意儿&＃xff01;所以我想写细一点。
一&＃xff1a;新建项目
如下图勾选include C&＃43;&＃43; support&＃xff0c;然后一路next&＃xff0c;直到finish。
新建NDK工程.png
二&＃xff1a;编译OpenSSL源码得到.so库
OpenSSL源码:github上搜索关键字【OpenSSL for Android】下载并编译&＃xff0c;拷贝所有.so到app/alley/lib/目录下&＃xff0c;拷贝OpenSSL所有头文件到app/alley/include/openssl/目录下。
alley文件目录.png
三&＃xff1a;gradle配置
#app目录下build.gradleapply plugin: &＃39;com.android.application&＃39;android {
compileSdkVersion 25
buildToolsVersion "25.0.2"
defaultConfig {
applicationId "com.alley.openssl"
minSdkVersion 15
targetSdkVersion 25
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
externalNativeBuild {
cmake {
cppFlags "-std&＃61;c&＃43;&＃43;11 -frtti -fexceptions"
//目标平台&＃xff0c;若需要更多平台的请自行配置
abiFilters &＃39;armeabi&＃39;
}
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile(&＃39;proguard-android.txt&＃39;), &＃39;proguard-rules.pro&＃39;
}
}
sourceSets {
main { //第三方.so库路径
jniLibs.srcDirs &＃61; [&＃39;E:\\AndroidSpace\\OpenSSL\\app\\alley\\lib&＃39;]
}
}
externalNativeBuild {
cmake {
path "CMakeLists.txt"
}
}
}
dependencies {
compile fileTree(dir: &＃39;libs&＃39;, include: [&＃39;*.jar&＃39;])
androidTestCompile(&＃39;com.android.support.test.espresso:espresso-core:2.2.2&＃39;, {
exclude group: &＃39;com.android.support&＃39;, module: &＃39;support-annotations&＃39;
})
compile &＃39;com.android.support:appcompat-v7:25.3.1&＃39;
compile &＃39;com.android.support.constraint:constraint-layout:1.0.0-alpha8&＃39;
testCompile &＃39;junit:junit:4.12&＃39;}
四&＃xff1a;CMakeLists脚本
CMakeLists脚本语法请自行查阅
# For more information about using CMake with Android Studio, read the# documentation: https://d.android.com/studio/projects/add-native-code.html# Sets the minimum version of CMake required to build the native library.cmake_minimum_required(VERSION 3.4.1)#C&＃43;&＃43;编译set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std&＃61;gnu&＃43;&＃43;11")#配置加载头文件include_directories(E:/AndroidSpace/OpenSSL/app/alley/include)#动态方式加载add_library(openssl SHARED IMPORTED )
add_library(ssl SHARED IMPORTED )#引入第三方.so库set_target_properties(openssl PROPERTIES IMPORTED_LOCATION E:/AndroidSpace/OpenSSL/app/alley/lib/${ANDROID_ABI}/libcrypto.so)
set_target_properties(ssl PROPERTIES IMPORTED_LOCATION E:/AndroidSpace/OpenSSL/app/alley/lib/${ANDROID_ABI}/libssl.so)# Creates and names a library, sets it as either STATIC# or SHARED, and provides the relative paths to its source code.# You can define multiple libraries, and CMake builds them for you.# Gradle automatically packages shared libraries with your APK.add_library( # Sets the name of the library.
signature # Sets the library as a shared library.
SHARED # Provides a relative path to your source file(s).
src/main/cpp/signature.cpp )# Searches for a specified prebuilt library and stores the path as a# variable. Because CMake includes system libraries in the search path by# default, you only need to specify the name of the public NDK library# you want to add. CMake verifies that the library exists before# completing its build.find_library( # Sets the name of the path variable.
log-lib # Specifies the name of the NDK library that
# you want CMake to locate.
log )# Specifies libraries CMake should link to your target library. You# can link multiple libraries, such as libraries you define in this# build script, prebuilt third-party libraries, or system libraries.target_link_libraries( # Specifies the target library.
signature
openssl
ssl
android # Links the target library to the log library
# included in the NDK.
${log-lib} )
五&＃xff1a;加解密
HmacSHA1算法得到签名结果为十六进制数。在本项目中对其进行Base64编码&＃xff0c;发现编码结果为28位的&＃xff0c;这和用Java代码实现的完全不同&＃xff08;Java实现的是56位&＃xff09;&＃xff0c;在线base64编码测试结果也为56位。原因是什么呢&＃xff1f;
待编码数据是按照** %02x 格式输出的值&＃xff0c;然后用这个值再次进行base64编码。在这里解释一下 %02x&＃xff1a;按照十六进制进行数据输出&＃xff0c;不足两位&＃xff0c;则在之前补0&＃xff0c;否则按实际数据输出。 所以用到了sprintf(char *, const char *, ...)和strcat(char , const char )函数&＃xff0c;这才是重点啊&＃xff0c;不太容易发现。在开发过程中注意C&＃43;&＃43;函数名与native方法的关系。将最后编译生成的libsignature.so拷贝你的项目中就可以使用了。秘钥自己设定&＃xff0c;注意不要泄露了。更多详情请阅读源码。
#include
LOGI("HmacSHA1->准备获取待加密数据");
jbyte *value &＃61; env->GetByteArrayElements(value_, NULL);
LOGI("HmacSHA1->准备计算待加密数据长度"); size_t value_Len &＃61; env->GetArrayLength(value_); unsigned int result_len; unsigned char result[EVP_MAX_MD_SIZE]; char buff[EVP_MAX_MD_SIZE]; char hex[EVP_MAX_MD_SIZE];
LOGI("HmacSHA1->准备进行加密计算");
HMAC(EVP_sha1(), key, strlen(key), (unsigned char *) value, value_Len, result, &result_len);
LOGI("HmacSHA1->加密计算结束"); strcpy(hex, ""); for (int i &＃61; 0; i !&＃61; result_len; i&＃43;&＃43;) { sprintf(buff, "%02x", result[i]); strcat(hex, buff);
}
LOGI("HmacSHA1->");
LOGI("%s", hex);
env->ReleaseByteArrayElements(value_, value, 0);
LOGI("HmacSHA1->jni释放数据结束");
jbyteArray signature &＃61; env->NewByteArray(strlen(hex));
env->SetByteArrayRegion(signature, 0, strlen(hex), (jbyte *) hex);
LOGI("HmacSHA1->准备以ByteArray格式返回数据"); return signature;
}
六&＃xff1a;测试
待签名数据&＃xff1a;Android CMake轻松实现基于OpenSSL的HmacSHA1签名
秘钥&＃xff1a;5fd6s4gs8f7s1dfv23sdf4ag65rg4arhb4fb1f54bgf5gbvf1534as
在线签名校验&＃xff1a;http://tool.oschina.net/encrypt?type&＃61;2&＃xff0c;经测试代码签名和在线签名结果相同。
下载代码运行&＃xff0c;在控制台中输入“body”&＃xff0c;将看到所有调试信息。欢迎star&＃xff0c;fork&＃xff0c;转载。
源码&＃xff1a;https://github.com/GitPhoenix/OpenSSL
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