title: No reference to BIO-functions when linking OpenSSL
body: <p>I'm trying to compile a c-program with openssl-references. I'm using Linux Mint 17.1 and the development package "libssl-dev" is installed.</p>
  
  <pre><code>#include &lt;openssl/bio.h&gt;
  #include &lt;openssl/err.h&gt;
  #include &lt;openssl/ssl.h&gt;
  ...
  
  void send_smtp_request(BIO *bio, const char *req)
  {
      BIO_puts(bio, req);
      BIO_flush(bio);
      printf("%s", req);     
  }
  </code></pre>
  
  <p>If I compile the code with:</p>
  
  <pre><code>gcc -o client bio-ssl-smtpcli2.c
  </code></pre>
  
  <p>I get the this error:</p>
  
  <pre><code>/tmp/ccCHrti2.o: In function 'send_smtp_request':
  bio-ssl-smtpcli2.c:(.text+0x1f):  undefined reference to 'BIO_puts'
  bio-ssl-smtpcli2.c:(.text+0x3a):  undefined reference to 'BIO_ctrl'
  </code></pre>
  
  <p>Does someone have an idea how to fix this?</p>