title: Why is QsslSocket working with Qt 5.3 but not Qt 5.7 on Debian Stretch?
body: <p>I have an app that uses the <a href="http://doc.qt.io/qt-5/qwebsocket.html" rel="noreferrer" title="QWebsocket class">QWebSocket class</a> but not SSL. It works fine when I execute a version compiled with Qt 5.3 but a Qt 5.7 executable freezes on the following warnings:</p>
  
  <pre><code>QSslSocket: cannot resolve CRYPTO_num_locks
  QSslSocket: cannot resolve CRYPTO_set_id_callback
  QSslSocket: cannot resolve CRYPTO_set_locking_callback
  QSslSocket: cannot resolve ERR_free_strings
  QSslSocket: cannot resolve EVP_CIPHER_CTX_cleanup
  QSslSocket: cannot resolve EVP_CIPHER_CTX_init
  QSslSocket: cannot resolve sk_new_null
  QSslSocket: cannot resolve sk_push
  QSslSocket: cannot resolve sk_free
  QSslSocket: cannot resolve sk_num
  QSslSocket: cannot resolve sk_pop_free
  QSslSocket: cannot resolve sk_value
  QSslSocket: cannot resolve SSL_library_init
  QSslSocket: cannot resolve SSL_load_error_strings
  QSslSocket: cannot resolve SSL_get_ex_new_index
  QSslSocket: cannot resolve SSLv2_client_method
  QSslSocket: cannot resolve SSLv3_client_method
  QSslSocket: cannot resolve SSLv23_client_method
  QSslSocket: cannot resolve SSLv2_server_method
  QSslSocket: cannot resolve SSLv3_server_method
  QSslSocket: cannot resolve SSLv23_server_method
  QSslSocket: cannot resolve X509_STORE_CTX_get_chain
  QSslSocket: cannot resolve OPENSSL_add_all_algorithms_noconf
  QSslSocket: cannot resolve OPENSSL_add_all_algorithms_conf
  QSslSocket: cannot resolve SSLeay
  QSslSocket: cannot resolve SSLeay_version
  QSslSocket: cannot call unresolved function CRYPTO_num_locks
  QSslSocket: cannot call unresolved function CRYPTO_set_id_callback
  QSslSocket: cannot call unresolved function CRYPTO_set_locking_callback
  QSslSocket: cannot call unresolved function SSL_library_init
  QSslSocket: cannot call unresolved function SSLv23_client_method
  QSslSocket: cannot call unresolved function sk_num
  </code></pre>
  
  <p>I am not seeing these warnings in the 5.3 version (that works properly), which suggests that I should not ignore them, <a href="https://stackoverflow.com/questions/26361145/qsslsocket-error-when-ssl-is-not-used">as asked in this question</a>. Also, <a href="https://stackoverflow.com/questions/10846536/unresolved-functions-while-working-with-qsslsocket"><code>QT += network</code> is already in my src.pro</a>.</p>
  
  <p>I was led to believe that <a href="https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=797926" rel="noreferrer">Debian dropped these symbols from the openssl package</a>. Could anyone tell me what's going on here and how I could fix this?</p>
  
  <h2>System information</h2>
  
  <p>I'm running on Debian stretch</p>
  
  <pre><code>$ uname -r
  4.8.0-2-amd64
  </code></pre>
  
  <p>I have openssl and libssl-dev installed</p>
  
  <pre><code>openssl is already the newest version (1.1.0c-2). 
  libssl-dev is already the newest version (1.1.0c-2).
  </code></pre>
  
  <p>I've tried running this with Qt 5.3 and 5.7</p>
  
  <pre><code>$ qmake -v
  QMake version 3.0
  Using Qt version 5.7.1 in /usr/lib/x86_64-linux-gnu
  </code></pre>