OpenSSL实践 Android下的编译和使用

# 在D盘下建立NDK目录
mkdir /mnt/d/ndk
cd /mnt/d/ndk
wget https://dl.google.com/android/repository/android-ndk-r14b-linux-x86_64.zip

# 解压
unzip android-ndk-r14b-linux-x86_64.zip

# 如果提示unzip为无效命令，可以使用apt-get进行安装
sudo apt-get install unzip

# 下载源码
cd /mnt/d
wget https://www.openssl.org/source/openssl-1.1.0f.tar.gz
# 解压源码
tar -zxvf openssl-1.1.0f.tar.gz

#拉取setenv-android.sh，我们需要这个脚本来给我们配置环境
cd /mnt/d/openssl-1.1.0f
wget https://wiki.openssl.org/images/7/70/Setenv-android.sh
# 注意这个文件是大写开头的，我们稍微修改一下名称，方便使用
mv Setenv-android.sh setenv-android.sh

_ANDROID_NDK="android-ndk-r9"
# 修改为：
_ANDROID_NDK="android-ndk-r14b"
# 因为我们使用的是R14B这个版本的NDK

_ANDROID_EABI="arm-linux-androideabi-4.8"
修改为GCC 4.9
_ANDROID_EABI="arm-linux-androideabi-4.9"

export ANDROID_NDK_ROOT=/mnt/d/ndk/android-ndk-r14b
source ./setenv-android.sh
# 输出
ANDROID_NDK_ROOT: /mnt/d/ndk/android-ndk-r14b
ANDROID_ARCH: arch-arm
ANDROID_EABI: arm-linux-androideabi-4.9
ANDROID_API: android-18
ANDROID_SYSROOT: /mnt/d/ndk/android-ndk-r14b/platforms/android-18/arch-arm
ANDROID_TOOLCHAIN: /mnt/d/ndk/android-ndk-r14b/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin
FIPS_SIG: /mnt/d/openssl-1.1.0f/util/incore
CROSS_COMPILE: arm-linux-androideabi-
ANDROID_DEV: /mnt/d/ndk/android-ndk-r14b/platforms/android-18/arch-arm/usr

mkdir /mnt/d/openssl-output

# 配置openssl
./config no-shared no-ssl2 no-ssl3 no-comp no-hw no-engine \
     --openssldir=/mnt/d/openssl-output/$ANDROID_API --prefix=/mnt/d/openssl-output/$ANDROID_API

#编译
make depend
make all -j8 
# -j8 表示并发的编译"线程数"，建议设置成CPU线程数一致

make install

├─androidTest
│  └─java
│      └─com
│          └─example
│              └─summer
│                  └─myapplication
├─main
│  ├─cpp
│  │  ├─libs
│  │  └─openssl
│  ├─java
│  │  └─com
│  │      └─example
│  │          └─summer

# 表示把src/main/cpp加入include目录，这样在代码中，使用：#include <...>就能访问到头文件
include_directories(src/main/cpp)

# 添加两个预编译库
add_library(openssl-crypto
    STATIC
    IMPORTED)

set_target_properties(openssl-crypto
                      PROPERTIES IMPORTED_LOCATION
                      ${CMAKE_SOURCE_DIR}/src/main/cpp/libs/libcrypto.a )

add_library(openssl-ssl
  STATIC
  IMPORTED)

set_target_properties(openssl-ssl
                    PROPERTIES IMPORTED_LOCATION
                    ${CMAKE_SOURCE_DIR}/src/main/cpp/libs/libssl.a )

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib})

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       ${log-lib} openssl-ssl openssl-crypto)

android {
    compileSdkVersion 25
    buildToolsVersion "26.0.0"
    defaultConfig {
        applicationId "com.example.summer.myapplication"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                cppFlags "-std=c++11 -frtti -fexceptions"
                // 下面这样是增加的
                arguments "-DANDROID_ABI=armeabi-v7a"
            }
        }
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    externalNativeBuild {
        cmake {
            path "CMakeLists.txt"
        }
    }
}

#include "openssl/crypto.h"

    std::string hello = "Hello from C++";
    return env->NewStringUTF(hello.c_str());

return env->NewStringUTF(OpenSSL_version(OPENSSL_VERSION));