ucspi-tls(2)                  System Calls Manual                 ucspi-tls(2)



NAME
       UCSPI-TLS - advanced and secure communication between server and prog

DESCRIPTON
       A  UCSPI-TLS  enhanced  server makes optional SSL services available to
       the client by providing three file descriptors:  a  control  socket,  a
       reading pipe, and a writing pipe.

       The  file  descriptor number of the control socket will be in the envi‐
       ronment variable $SSLCTLFD.

       The file descriptor number of the reading pipe will be in the  environ‐
       ment variable $SSLREADFD, and the file descriptor number of the writing
       pipe will be in the environment variable $SSLWRITEFD.

       It's possible for all three of these file descriptors to be the same.


USAGE
       UCSPI-TLS provides standard IN and OUT (file descriptors 0  and  1)  to
       connected directly to the socket, for unencrypted communication.

       The control socket must accept at least these two commands:

       y      Start TLS.

       Y      Start  TLS,  and  send  optional SSL connection information back
              over the control socket.

       The SSL connection information will be in the in the form of  an  envi‐
       ronment  string, with zero or more environment variables, terminated by
       two ASCII NULL's.  Each environment variable is stored  as  "VAR=val ",
       and  an  additional trailing   is used to indicate the end of all envi‐
       ronment variables.  If there are no variables to set,  "  "  should  be
       used.

       When  TLS is started, the UCSPI-TLS enabled server will take control of
       the socket, and the application is  expected  to  switch  to  the  file
       descriptors  in  $SSLREADFD  and  $SSLWRITEFD for all future communica‐
       tions.  Using the regular socket after  activating  TLS  will  probably
       just confuse the client.

REFERENCE
       Where  possible,  the environment variables set should be the same ones
       as Apache's mod_ssl:

       http://httpd.apache.org/docs-2.4/mod/mod_ssl.html

CREDITS
       Scott Gifford, Charlie Brady



                                                                  ucspi-tls(2)