title: Where are the header files & libraries of the OpenSSL package that comes with macOS?
body: <p>I just installed macOS Catalina version 10.15.4 (19E287).</p>
  
  <p>It comes with OpenSSL (well actually LibreSSL) installed.</p>
  
  <pre><code>$ openssl version
  LibreSSL 2.6.5
  </code></pre>
  
  <p>I'm installing PostgreSQL from source "with support for SSL (encrypted) connections", by supplying the <code>--with-openssl</code> command line option to <code>configure</code>.</p>
  
  <blockquote>
  <pre><code>--with-openssl
  
      Build with support for SSL (encrypted) connections. This
      requires the OpenSSL package to be installed. "configure" will
      check for the required header files and libraries to make sure
      that your OpenSSL installation is sufficient before proceeding.
  </code></pre>
  </blockquote>
  
  <p>So where do I tell the compiler to look for the "required header files and libraries"?</p>
  
  <p>Ie, what do I put for the <code>--with-includes</code> and <code>--with-libraries</code> command line options to <code>configure</code>?</p>
  
  <blockquote>
  <pre><code>--with-includes=DIRECTORIES
  
      "DIRECTORIES" is a colon-separated list of directories that will
      be added to the list the compiler searches for header files. If
      you have optional packages (such as GNU Readline) installed in a
      non-standard location, you have to use this option and probably
      also the corresponding "--with-libraries" option.
  
      Example: --with-includes=/opt/gnu/include:/usr/sup/include.
  
  --with-libraries=DIRECTORIES
  
      "DIRECTORIES" is a colon-separated list of directories to search
      for libraries. You will probably have to use this option (and
      the corresponding "--with-includes" option) if you have packages
      installed in non-standard locations.
  
      Example: --with-libraries=/opt/gnu/lib:/usr/sup/lib.
  </code></pre>
  </blockquote>
  
  <p>I don't want to use Homebrew. I'd rather install LibreSSL from source if I must.</p>