【随笔记】NDK 编译开源库 nghttp2/openssl/curl

工作中有遇到需要使用支持 http2 访问的 https 安全加密的开源库，便于使用 http2 与云端通信，经过调研发现 libcurl 可以满足需求，但是 libcurl 本身也是需要依赖于 nghttp2 来支持 http2 通信，以及需要 openssl 来实现安全加密的通信（访问带 https 的连接）。

编译第三方开源库，主要的原理是在于通过设置环境变量，来指明编译工具链和头文件所在的位置，再通过 configure 生成合适的 makefile。

一、环境准备

官方网站下载 NDK：

wget https://dl.google.com/android/repository/android-ndk-r19c-linux-x86_64.zip

解压并拷贝到指定目录：

unzip android-ndk-r19c-linux-x86_64.zip
sudo mkdir /opt/ndk
sudo cp -r android-ndk-r19c /opt/ndk

额外知识记录：(本文未使用此方法)

NDK 目录中有一个脚本可以创建独立编译工具链，具体可以参考：独立工具链（已弃用）  |  Android NDK  |  Android Developers

./make-standalone-toolchain.sh --install-dir=指定独立编译工具链存放的路径

二、编译 nghttp2

源码下载和解压：

wget https://github.com/nghttp2/nghttp2/releases/download/v1.44.0/nghttp2-1.44.0.tar.gz
tar -zxvf nghttp2-1.44.0.tar.gz 

编写编译脚本，并放置到 nghttp2 源码根目录：android_build_nghttp2.sh

#!/bin/sh

export PREFIX=`pwd`/../build/nghttp2
export TOOLCHAIN=/opt/ndk/android-ndk-r19c/toolchains/llvm/prebuilt/linux-x86_64
export PATH="$TOOLCHAIN"/bin:"$PATH"
export CC="$TOOLCHAIN"/bin/armv7a-linux-androideabi19-clang
export CXX="$TOOLCHAIN"/bin/armv7a-linux-androideabi19-clang++
export CPPFLAGS="-fPIE -I$PREFIX/include"
export PKG_CONFIG_LIBDIR="$PREFIX/lib/pkgconfig"
export LDFLAGS="-fPIE -pie -L$PREFIX/lib"
export TOOL=arm-linux-androideabi
export LD=$TOOLCHAIN/bin/${TOOL}-ld
export AR=$TOOLCHAIN/bin/${TOOL}-ar
export RANLIB=$TOOLCHAIN/bin/${TOOL}-ranlib
export STRIP=$TOOLCHAIN/bin/${TOOL}-strip

./configure \
    --enable-shared \
    --host=arm-linux-androideabi \
    --build=`dpkg-architecture -qDEB_BUILD_GNU_TYPE` \
    --prefix="$PREFIX" \
    --without-libxml2 \
    --disable-python-bindings \
    --disable-examples \
    --disable-threads    

if [ $? -eq 0 ]; then
	make -j16 && make install
fi

执行编译脚本后会在源码外层目录 build/nghttp2 生成编译的动态库、静态库、头文件：

./android_build_nghttp2.sh

三、编译 openssl

源码下载和解压：

wget https://www.openssl.org/source/openssl-1.1.1k.tar.gz
tar -zxvf openssl-1.1.1k.tar.gz

修改编译配置脚本，并放置到 openssl 源码根目录，该编译脚本同时适用于目前最新版的  3.0.0 ：android_build_openssl.sh

配置脚本修改自官方的配置脚本(其实可以精简)：https://wiki.openssl.org/images/7/70/Setenv-android.sh

#!/bin/bash
# Cross-compile environment for Android on ARMv7 and x86
#
# Contents licensed under the terms of the OpenSSL license
# http://www.openssl.org/source/license.html
#
# See http://wiki.openssl.org/index.php/FIPS_Library_and_Android
#   and http://wiki.openssl.org/index.php/Android

#####################################################################

export ANDROID_NDK_HOME=/opt/ndk/android-ndk-r19c
export ANDROID_NDK_ROOT=/opt/ndk/android-ndk-r19c
export PATH=$PATH:$ANDROID_NDK_ROOT/toolchains/llvm/prebuilt/linux-x86_64/bin:$ANDROID_NDK_ROOT/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin

# Set ANDROID_NDK_ROOT to you NDK location. For example,
# /opt/android-ndk-r8e or /opt/android-ndk-r9. This can be done in a
# login script. If ANDROID_NDK_ROOT is not specified, the script will
# try to pick it up with the value of _ANDROID_NDK_ROOT below. If
# ANDROID_NDK_ROOT is set, then the value is ignored.
# _ANDROID_NDK="android-ndk-r8e"
_ANDROID_NDK="android-ndk-r19c"
# _ANDROID_NDK="android-ndk-r10"

# Set _ANDROID_EABI to the EABI you want to use. You can find the
# list in $ANDROID_NDK_ROOT/toolchains. This value is always used.
# _ANDROID_EABI="x86-4.6"
# _ANDROID_EABI="arm-linux-androideabi-4.6"
_ANDROID_EABI="arm-linux-androideabi-4.9"

# Set _ANDROID_ARCH to the architecture you are building for.
# This value is always used.
# _ANDROID_ARCH=arch-x86
_ANDROID_ARCH=arch-arm

# Set _ANDROID_API to the API you want to use. You should set it
# to one of: android-14, android-9, android-8, android-14, android-5
# android-4, or android-3. You can't set it to the latest (for
# example, API-17) because the NDK does not supply the platform. At
# Android 5.0, there will likely be another platform added (android-22?).
# This value is always used.
# _ANDROID_API="android-14"
_ANDROID_API="android-19"
# _ANDROID_API="android-19"

#####################################################################

# If the user did not specify the NDK location, try and pick it up.
# We expect something like ANDROID_NDK_ROOT=/opt/android-ndk-r8e
# or ANDROID_NDK_ROOT=/usr/local/android-ndk-r8e.

if [ -z "$ANDROID_NDK_ROOT" ]; then

  _ANDROID_NDK_ROOT=""
  if [ -z "$_ANDROID_NDK_ROOT" ] && [ -d "/usr/local/$_ANDROID_NDK" ]; then
    _ANDROID_NDK_ROOT="/usr/local/$_ANDROID_NDK"
  fi

  if [ -z "$_ANDROID_NDK_ROOT" ] && [ -d "/opt/$_ANDROID_NDK" ]; then
    _ANDROID_NDK_ROOT="/opt/$_ANDROID_NDK"
  fi

  if [ -z "$_ANDROID_NDK_ROOT" ] && [ -d "$HOME/$_ANDROID_NDK" ]; then
    _ANDROID_NDK_ROOT="$HOME/$_ANDROID_NDK"
  fi

  if [ -z "$_ANDROID_NDK_ROOT" ] && [ -d "$PWD/$_ANDROID_NDK" ]; then
    _ANDROID_NDK_ROOT="$PWD/$_ANDROID_NDK"
  fi

  # If a path was set, then export it
  if [ ! -z "$_ANDROID_NDK_ROOT" ] && [ -d "$_ANDROID_NDK_ROOT" ]; then
    export ANDROID_NDK_ROOT="$_ANDROID_NDK_ROOT"
  fi
fi

# Error checking
# ANDROID_NDK_ROOT should always be set by the user (even when not running this script)
# http://groups.google.com/group/android-ndk/browse_thread/thread/a998e139aca71d77
if [ -z "$ANDROID_NDK_ROOT" ] || [ ! -d "$ANDROID_NDK_ROOT" ]; then
  echo "Error: ANDROID_NDK_ROOT is not a valid path. Please edit this script."
  # echo "$ANDROID_NDK_ROOT"
  # exit 1
fi

# Error checking
if [ ! -d "$ANDROID_NDK_ROOT/toolchains" ]; then
  echo "Error: ANDROID_NDK_ROOT/toolchains is not a valid path. Please edit this script."
  # echo "$ANDROID_NDK_ROOT/toolchains"
  # exit 1
fi

# Error checking
if [ ! -d "$ANDROID_NDK_ROOT/toolchains/$_ANDROID_EABI" ]; then
  echo "Error: ANDROID_EABI is not a valid path. Please edit this script."
  # echo "$ANDROID_NDK_ROOT/toolchains/$_ANDROID_EABI"
  # exit 1
fi

#####################################################################

# Based on ANDROID_NDK_ROOT, try and pick up the required toolchain. We expect something like:
# /opt/android-ndk-r83/toolchains/arm-linux-androideabi-4.7/prebuilt/linux-x86_64/bin
# Once we locate the toolchain, we add it to the PATH. Note: this is the 'hard way' of
# doing things according to the NDK documentation for Ice Cream Sandwich.
# https://android.googlesource.com/platform/ndk/+/ics-mr0/docs/STANDALONE-TOOLCHAIN.html

ANDROID_TOOLCHAIN=""
for host in "linux-x86_64" "linux-x86" "darwin-x86_64" "darwin-x86"
do
  if [ -d "$ANDROID_NDK_ROOT/toolchains/$_ANDROID_EABI/prebuilt/$host/bin" ]; then
    ANDROID_TOOLCHAIN="$ANDROID_NDK_ROOT/toolchains/$_ANDROID_EABI/prebuilt/$host/bin"
    break
  fi
done

# Error checking
if [ -z "$ANDROID_TOOLCHAIN" ] || [ ! -d "$ANDROID_TOOLCHAIN" ]; then
  echo "Error: ANDROID_TOOLCHAIN is not valid. Please edit this script."
  # echo "$ANDROID_TOOLCHAIN"
  # exit 1
fi

case $_ANDROID_ARCH in
	arch-arm)
      ANDROID_TOOLS="arm-linux-androideabi-ranlib arm-linux-androideabi-ld"
	  ;;
	arch-x86)
      ANDROID_TOOLS="i686-linux-android-gcc i686-linux-android-ranlib i686-linux-android-ld"
	  ;;
	*)
	  echo "ERROR ERROR ERROR"
	  ;;
esac

for tool in $ANDROID_TOOLS
do
  # Error checking
  if [ ! -e "$ANDROID_TOOLCHAIN/$tool" ]; then
    echo "Error: Failed to find $tool. Please edit this script."
    # echo "$ANDROID_TOOLCHAIN/$tool"
    # exit 1
  fi
done

# Only modify/export PATH if ANDROID_TOOLCHAIN good
if [ ! -z "$ANDROID_TOOLCHAIN" ]; then
  export ANDROID_TOOLCHAIN="$ANDROID_TOOLCHAIN"
  export PATH="$ANDROID_TOOLCHAIN":"$PATH"
fi

#####################################################################

# For the Android SYSROOT. Can be used on the command line with --sysroot
# https://android.googlesource.com/platform/ndk/+/ics-mr0/docs/STANDALONE-TOOLCHAIN.html
export ANDROID_SYSROOT="$ANDROID_NDK_ROOT/platforms/$_ANDROID_API/$_ANDROID_ARCH"
export CROSS_SYSROOT="$ANDROID_SYSROOT"
export NDK_SYSROOT="$ANDROID_SYSROOT"

# Error checking
if [ -z "$ANDROID_SYSROOT" ] || [ ! -d "$ANDROID_SYSROOT" ]; then
  echo "Error: ANDROID_SYSROOT is not valid. Please edit this script."
  # echo "$ANDROID_SYSROOT"
  # exit 1
fi

#####################################################################

# If the user did not specify the FIPS_SIG location, try and pick it up
# If the user specified a bad location, then try and pick it up too.
if [ -z "$FIPS_SIG" ] || [ ! -e "$FIPS_SIG" ]; then

  # Try and locate it
  _FIPS_SIG=""
  if [ -d "/usr/local/ssl/$_ANDROID_API" ]; then
    _FIPS_SIG=`find "/usr/local/ssl/$_ANDROID_API" -name incore`
  fi

  if [ ! -e "$_FIPS_SIG" ]; then
    _FIPS_SIG=`find $PWD -name incore`
  fi

  # If a path was set, then export it
  if [ ! -z "$_FIPS_SIG" ] && [ -e "$_FIPS_SIG" ]; then
    export FIPS_SIG="$_FIPS_SIG"
  fi
fi

# Error checking. Its OK to ignore this if you are *not* building for FIPS
if [ -z "$FIPS_SIG" ] || [ ! -e "$FIPS_SIG" ]; then
  echo "Error: FIPS_SIG does not specify incore module. Please edit this script."
  # echo "$FIPS_SIG"
  # exit 1
fi

#####################################################################

# Most of these should be OK (MACHINE, SYSTEM, ARCH). RELEASE is ignored.
export MACHINE=armv7
export RELEASE=2.6.37
export SYSTEM=android
export ARCH=arm
export CROSS_COMPILE="arm-linux-androideabi-"

if [ "$_ANDROID_ARCH" == "arch-x86" ]; then
	export MACHINE=i686
	export RELEASE=2.6.37
	export SYSTEM=android
	export ARCH=x86
	export CROSS_COMPILE="i686-linux-android-"
fi

# For the Android toolchain
# https://android.googlesource.com/platform/ndk/+/ics-mr0/docs/STANDALONE-TOOLCHAIN.html
export ANDROID_SYSROOT="$ANDROID_NDK_ROOT/platforms/$_ANDROID_API/$_ANDROID_ARCH"
export SYSROOT="$ANDROID_SYSROOT"
export NDK_SYSROOT="$ANDROID_SYSROOT"
export ANDROID_NDK_SYSROOT="$ANDROID_SYSROOT"
export ANDROID_API="$_ANDROID_API"

# CROSS_COMPILE and ANDROID_DEV are DFW (Don't Fiddle With). Its used by OpenSSL build system.
# export CROSS_COMPILE="arm-linux-androideabi-"
export ANDROID_DEV="$ANDROID_NDK_ROOT/platforms/$_ANDROID_API/$_ANDROID_ARCH/usr"
export HOSTCC=gcc

VERBOSE=1
if [ ! -z "$VERBOSE" ] && [ "$VERBOSE" != "0" ]; then
  echo "ANDROID_NDK_ROOT: $ANDROID_NDK_ROOT"
  echo "ANDROID_ARCH: $_ANDROID_ARCH"
  echo "ANDROID_EABI: $_ANDROID_EABI"
  echo "ANDROID_API: $ANDROID_API"
  echo "ANDROID_SYSROOT: $ANDROID_SYSROOT"
  echo "ANDROID_TOOLCHAIN: $ANDROID_TOOLCHAIN"
  echo "FIPS_SIG: $FIPS_SIG"
  echo "CROSS_COMPILE: $CROSS_COMPILE"
  echo "ANDROID_DEV: $ANDROID_DEV"

  ./Configure android-arm --prefix=`pwd`/../build/openssl -D__ANDROID_API__=19 && make -j16 && make install
fi

执行编译脚本后会在源码外层目录中的 build/openssl 生成编译的动态库和头文件：./android_build_openssl.sh

./android_build_openssl.sh

四、编译 curl

源码下载和解压：

wget https://curl.se/download/curl-7.78.0.tar.gz
tar -zxvf curl-7.78.0.tar.gz

编写支持 http2 和 ssl 的编译配置脚本：android_build_curl.sh

#!/bin/bash

export TOOLCHAIN=/opt/ndk/android-ndk-r19c/toolchains/llvm/prebuilt/linux-x86_64
export CC="$TOOLCHAIN"/bin/armv7a-linux-androideabi19-clang
export CXX="$TOOLCHAIN"/bin/armv7a-linux-androideabi19-clang++
export TOOL=arm-linux-androideabi
export LD=$TOOLCHAIN/bin/${TOOL}-ld
export AR=$TOOLCHAIN/bin/${TOOL}-ar
export RANLIB=$TOOLCHAIN/bin/${TOOL}-ranlib
export STRIP=$TOOLCHAIN/bin/${TOOL}-strip
export PATH="$TOOLCHAIN"/bin:"$PATH"
export ARCH_FLAGS="-mthumb"
export CFLAGS="${ARCH_FLAGS} -fpic -ffunction-sections -funwind-tables -fstack-protector-all -fno-strict-aliasing -finline-limit=64"
export CXXFLAGS="${CFLAGS} -frtti -fexceptions"

./configure --prefix=`pwd`/../build/libcurl/ \
       --with-sysroot=$TOOLCHAIN/sysroot \
       --host=arm-linux-androideabi \
       --with-ssl=`pwd`/../build/openssl/ \
       --with-nghttp2=`pwd`/../build/nghttp2/ \
       --enable-ipv6 \
       --enable-static \
       --enable-threaded-resolver \
       --disable-dict \
       --disable-gopher \
       --disable-ldap --disable-ldaps \
       --disable-manual \
       --disable-pop3 --disable-smtp --disable-imap \
       --disable-rtsp \
       --disable-shared \
       --disable-smb \
       --disable-telnet \
       --disable-verbose

if [ $? -eq 0 ]; then
	make -j16 && make install
fi

执行编译脚本后会在源码外层目录中的 build/libcurl 生成编译的动态库和头文件：./android_build_curl.sh

./android_build_curl.sh

将 nghttp2 和 openssl 以及 curl 相关的库文件推入到 /system/lib，并执行 curl --version，即可检查 curl 是否支持 HTTP2 和 SSL：

实测访问网站：（证书文件从这里下载 https://curl.se/ca/cacert.pem）

注意：记得要同步系统时间，如果系统时间没有同步，会出现验证失败无法访问的情况。

五、综合下载并编译脚本

#!/bin/bash

echo -----------------------------------------------
echo build nghttp2 ......
echo -----------------------------------------------
wget https://github.com/nghttp2/nghttp2/releases/download/v1.44.0/nghttp2-1.44.0.tar.gz
if [ $? -ne 0 ]; then
	echo download failed .......
	exit -1
fi
tar -zxvf nghttp2-1.44.0.tar.gz
cp android_build_nghttp2.sh nghttp2-1.44.0/
cd nghttp2-1.44.0
./android_build_nghttp2.sh

if [ $? -ne 0 ]; then
	echo build error .......
	exit -1
fi

echo -----------------------------------------------
echo build openssl ......
echo -----------------------------------------------
cd ..
wget https://www.openssl.org/source/openssl-1.1.1k.tar.gz
if [ $? -ne 0 ]; then
	echo download failed .......
	exit -1
fi
tar -zxvf openssl-1.1.1k.tar.gz
cp android_build_openssl.sh openssl-1.1.1k/
cd openssl-1.1.1k
./android_build_openssl.sh

if [ $? -ne 0 ]; then
	echo build error .......
	exit -1
fi

echo -----------------------------------------------
echo build curl ......
echo -----------------------------------------------
cd ..
wget https://curl.se/download/curl-7.78.0.tar.gz
if [ $? -ne 0 ]; then
	echo download failed .......
	exit -1
fi
tar -zxvf curl-7.78.0.tar.gz
cp android_build_curl.sh curl-7.78.0/
cd curl-7.78.0
./android_build_curl.sh