无法使用 Windows 的 OpenSSL 支持交叉编译 cURL

Question

我正在尝试从 Linux (Debian Jessie) 为 Windows 进行交叉编译。我编译了zlib 和OpenSSL，cURL 的配置脚本确实找到了这些库，但是它仍然说 SSL 支持已关闭。

这是我使用的构建脚本：

# ZLIB
cd /builds
curl -O -J http://www.zlib.net/zlib-1.2.11.tar.gz
tar xf zlib-1.2.11.tar.gz
cd /builds/zlib-1.2.11
CC=x86_64-w64-mingw32-gcc ./configure --prefix=/usr/x86_64-w64-mingw32 --static
make && make install

# OPENSSL
cd /builds
curl -O -J https://www.openssl.org/source/openssl-1.1.0c.tar.gz
tar xf openssl-1.1.0c.tar.gz
cd /builds/openssl-1.1.0c
CROSS_COMPILE="x86_64-w64-mingw32-" ./Configure -DHAVE_STRUCT_TIMESPEC -lz -lws2_32 zlib mingw64 no-shared --prefix=/usr/x86_64-w64-mingw32
make depend
make && make install

# CURL
cd /builds
curl -O -J https://curl.haxx.se/download/curl-7.52.1.tar.gz
cd /builds/curl-7.52.1
./configure --prefix=/usr/x86_64-w64-mingw32 --host=x86_64-w64-mingw32 --enable-optimize --with-ssl=/usr/x86_64-w64-mingw32

它成功找到了该库，但由于缺少--with-ssl，SSL 刚刚被禁用

checking whether to enable Windows native SSL/TLS (Windows native builds only)... no
checking whether to enable Apple OS native SSL/TLS... no
checking for gdi32... yes
configure: PKG_CONFIG_LIBDIR will be set to "/usr/x86_64-w64-mingw32/lib/pkgconfig"
checking for x86_64-w64-mingw32-pkg-config... /usr/bin/pkg-config
checking for openssl options with pkg-config... found
configure: pkg-config: SSL_LIBS: "-lssl -lcrypto "
configure: pkg-config: SSL_LDFLAGS: "-L/usr/x86_64-w64-mingw32/lib "
configure: pkg-config: SSL_CPPFLAGS: "-I/usr/x86_64-w64-mingw32/include "
checking for HMAC_Update in -lcrypto... no
checking for HMAC_Init_ex in -lcrypto... no
checking for ssl_version in -laxtls... no
configure: WARNING: SSL disabled, you will not be able to use HTTPS, FTPS, NTLM and more.
configure: WARNING: Use --with-ssl, --with-gnutls, --with-polarssl, --with-cyassl, --with-nss, --with-axtls, --with-winssl, or --with-darwinssl to address this.
checking default CA cert bundle/path... configure: WARNING: skipped the ca-cert path detection when cross-compiling
no
checking whether to use builtin CA store of SSL library... no

完整日志：https://paste.kde.org/pwzewydif

Answer 1

为了交叉编译 curl 支持 ssl，我直接在 CPP_FLAGS 和 LD_FLAGS 中提供了位置，而不是使用 --with-ssl 提供路径：

export DESTDIR="$CURL_INSTALL_DIR"
export CPPFLAGS="-I${OPENSSL_INSTALL_DIR}/include -I${ZLIB_INSTALL_DIR}/include"
export LDFLAGS="-L${OPENSSL_INSTALL_DIR}/lib -L${ZLIB_INSTALL_DIR}/lib"
export LIBS="-lssl -lcrypto"

CURL_ARGS="--with-ssl --with-zlib --disable-ftp --disable-gopher 
    --disable-file --disable-imap --disable-ldap --disable-ldaps 
    --disable-pop3 --disable-proxy --disable-rtsp --disable-smtp 
    --disable-telnet --disable-tftp --without-gnutls --without-libidn 
    --without-librtmp --disable-dict"

chmod 777 buildconf
./buildconf
./configure --host="${CROSS_COMPILE}" $CURL_ARGS

make -j16
make install

查看curl cross compilation script

Answer 2

我花了整整一周的时间才为 cURL 启用 SSL。 从您的配置日志中，您需要将这两行启用为yes

checking for HMAC_Update in -lcrypto... no
checking for HMAC_Init_ex in -lcrypto... no

问题在于如何构建 OpenSSL。就我而言，我通过添加-fPIC -ldl 来构建 OpenSSL，如下所示

#For OpenSSL 1.0.2s
export USING_OPENSSL=./openssl-1.0.2s
export CROSS_COMPILE_PREFIX=mips-unknown-linux-uclibc-
export SSL_OPTIONS="enable-ssl-trace enable-shared enable-ssl enable-ssl2 enable-ssl3 enable-ssl3-method enable-
tls enable-tls1_1 enable-tls1_2 enable-weak-ssl-ciphers enable-unit-test enable-async enable-md2"

cd $USING_OPENSSL && CC=gcc AR=ar RANLIB=ranlib LD=ld ./Configure linux-mips32 -fPIC -ldl --openssldir=$USING_OPENSSL/OPSSL --prefix=$USING_OP
ENSSL/OPSSL --cross-compile-prefix=$CROSS_COMPILE_PREFIX $SSL_OPTIONS

make -C $USING_OPENSSL;
make install -C $USING_OPENSSL;

如果链接器undefined reference to 'TLS_DTPREL_VALUE' 有错误，请参考链接https://codeleading.com/article/82492718270/，链接上的修复可能不适用于您的OpenSSL，您必须修改它以适应您的OpenSSL 版本。

使用我的 OpenSSL 1.0.2s，构建目标不同，因此需要修改如下：

@echo Patch Makefile
sed -i -e 's/build_all:.*/build_all: build_libs/g' $USING_OPENSSL/Makefile
sed -i -e 's/build_libs:.*/build_libs: build_libcrypto build_libssl build_engines openssl.pc/g' $USING_OPENSSL/Makefile
sed -i -e 's/DIRS=   crypto ssl engines.*/DIRS=  crypto ssl engines/g' $USING_OPENSSL/Makefile

---

对于 cURL v7.48.0，我必须在 ./configure 之前运行 autoreconf，因为在识别 configuration.ac 的 -ldl 时存在一些问题。

cd $APP_CURL_DIR && autoreconf && LIBS="-ldl -lpthread" ./configure --prefix=$APP_CURL_DIR/curl --target=$COMPILE_TOOLCHAIN --host=$HOST CC
=mips-unknown-linux-uclibc-gcc --with-ssl=$USING_OPENSSL/OPSSL --enable-static

构建脚本是从 Makefile 复制的，因此如果有任何部分在您的环境中不可用，只需修改它以适合您的目标。

最后，在编译 cURL 时，如果您遇到 OpenSSL 标头存在但无法像 example code below 那样编译的问题。也许您不需要修改configure.ac，请先尝试autoconf 或autoreconf，然后像我上面发布的那样运行带有-ldl 选项的./configure。

configure: WARNING: pi.h: present but cannot be compiled
     configure: WARNING: pi.h:     check for missing prerequisite headers?
     configure: WARNING: pi.h: see the Autoconf documentation
     configure: WARNING: pi.h:     section "Present But Cannot Be Compiled"
     configure: WARNING: pi.h: proceeding with the compiler's result
     configure: WARNING:     ## -------------------------------------- ##
     configure: WARNING:     ## Report this to bug-example@example.org ##
     configure: WARNING:     ## -------------------------------------- ##