一、问题：

qt.network.ssl: QSslSocket: cannot resolve CRYPTO_num_locks
qt.network.ssl: QSslSocket: cannot resolve CRYPTO_set_id_callback
qt.network.ssl: QSslSocket: cannot resolve CRYPTO_set_locking_callback
qt.network.ssl: QSslSocket: cannot resolve ERR_free_strings
qt.network.ssl: QSslSocket: cannot resolve sk_new_null
qt.network.ssl: QSslSocket: cannot resolve sk_push
qt.network.ssl: QSslSocket: cannot resolve sk_free
qt.network.ssl: QSslSocket: cannot resolve sk_num
qt.network.ssl: QSslSocket: cannot resolve sk_pop_free
qt.network.ssl: QSslSocket: cannot resolve sk_value
qt.network.ssl: QSslSocket: cannot resolve SSL_library_init
qt.network.ssl: QSslSocket: cannot resolve SSL_load_error_strings
qt.network.ssl: QSslSocket: cannot resolve SSLv2_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv3_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv23_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv2_server_method
qt.network.ssl: QSslSocket: cannot resolve SSLv3_server_method
qt.network.ssl: QSslSocket: cannot resolve SSLv23_server_method
qt.network.ssl: QSslSocket: cannot resolve X509_STORE_CTX_get_chain
qt.network.ssl: QSslSocket: cannot resolve OPENSSL_add_all_algorithms_noconf
qt.network.ssl: QSslSocket: cannot resolve OPENSSL_add_all_algorithms_conf
qt.network.ssl: QSslSocket: cannot resolve SSLeay
qt.network.ssl: QSslSocket: cannot resolve SSLeay_version
qt.network.ssl: QSslSocket: cannot call unresolved function CRYPTO_num_locks
qt.network.ssl: QSslSocket: cannot call unresolved function CRYPTO_set_id_callback
qt.network.ssl: QSslSocket: cannot call unresolved function CRYPTO_set_locking_callback
qt.network.ssl: QSslSocket: cannot call unresolved function SSL_library_init
Could not register file downloader for https protocol: QSslSocket::supportsSsl() returns false
[1] Warning: QSslSocket: cannot call unresolved function SSLv23_client_method
[4] Warning: QSslSocket: cannot call unresolved function sk_num

二、原因： openssl不兼容

三、解决：

3.1.编译安装openssl报错

POD document had syntax errors at /usr/bin/pod2man line 69. make: *** [install_docs]

解决办法：

rm -f /usr/bin/pod2man 

3.2.清除老的openssl

apt-get purge openssl
rm -rf /etc/ssl #删除配置文件

3.3.安装兼容版本的openssl

 prefix 是安装目录，openssldir 是配置文件目录，另外建议安装两次，shared 作用是生成动态连接库。

wget ftp://ftp.openssl.org/source/openssl-1.0.0c.tar.gz
tar -zxf openssl-1.0.0c.tar.gz
cd openssl-1.0.0c/
./config  --prefix=/usr/local --openssldir=/usr/local/ssl
make && make install

./config shared --prefix=/usr/local --openssldir=/usr/local/ssl
make clean
make && make install

3.4.查看安装目录应该在/usr/local/lib下.

3.5.在命令行输入:

export LD_LIBRARY_PATH=/usr/local/lib/:$LD_LIBRARY_PATH

  备注:网上有说将编译好的openssl的拷贝到Qt安装目录，然并不起作用

3.6. 在命令行输入

./qt-opensource-linux-x64-5.5.1.run