NAME

       sslserver - accept TLS connections and setup SSL CTX


SYNOPSIS

       sslserver [ opts ] host port prog


DESCRIPTION

       opts is a series of getopt-style options, host is a host name or IP
       address, port is a TCP port, and prog is one or more arguments
       specifying a program to run for each accepted connection.

       The server's address is given by host and port.



BINDINGS

       sslserver will be attached to the primary IP address of host while the
       host name is fed through qualification using dns_ip6_qualify.  If host
       is given as dotted decimal IPv4 or compactified IPv6 address, sslserver
       will bind uniquely to those.  In order to bind sslserver to a LLU IPv6
       address (ie. fe80::a:b:c) additionally the interface name -Iifname has
       to be provided.

       Note: The kernel might use temporary changing SLAAC addresses.

       sslserver can be instructed to be multi-homing capable while binding to
       all available IP addresses. Now host is given as '0' or '::' perhaps
       accompanied by the flags -4 or -6.

       Further, sslserver can be forced to provide dual-stack capabilities,
       thus allowing IPv4 and IPv6 clients to attach to the same instance once
       host equals ':0' as pseudo IP address.

       port may be a numeric port number or a port name.  If port is 0,
       sslserver will choose a free port.



SERVING

       sslserver listens for connections from TCP clients.  Typically, for
       each connection, it runs prog, with file descriptor 0 reading from, and
       file descriptor 1 writing to a child process ssl.  If however sslserver
       is called with the option -n, it communcates with prog on mutually
       chosen, arbitrary file descriptors.  prog needs to support the UCSPI-
       TLS API.  The ssl process attempts an SSL accept via the network.  If
       it succeeds, it translates data between prog and the network,
       performing any necessary SSL encoding and decoding.  Before running
       prog, sslserver reads and sets certain environment variables.

       sslserver exits when it receives SIGTERM.


OPTIONS

       General Options:

       -q     Quiet. Do not print error messages.

       -Q     (Default.) Print error messages.
       -6     Use IPv6 connections. This will set PROTO to TCP6 and put IPv6
              addresses in TCP6LOCALIP and TCP6REMOTEIP.

       -c n   Do not handle more than n simultaneous connections.  If there
              are n simultaneous connections copies of prog running, defer
              acceptance of a new connection until one copy finishes.  n must
              be a positive integer. The default value is 40.

       -x cdb Follow the rules compiled into cdb by tcprules.  These rules may
              specify setting environment variables or rejecting connections
              from bad sources.  You can rerun tcprules to change the rules
              while sslserver is running.

       -X     With -x cdb, allow connections even if -I cdb does not exist.
              Normally sslserver will drop the connection if cdb does not
              exist.

       -B banner
              Write banner to the network immediately after each SSL
              connection is made. The banner is subject to SSL encryption.

       -g gid Switch group ID to gid after preparing to receive connections.
              gid must be a positive integer.

       -u uid Switch user ID to uid after preparing to receive connections.
              uid must be a positive integer.

       -U     Same as -g $GID -u $UID. Typically, $GID and $UID are set by
              envuidgid.

       -I ifname
              Bind to the network interface ifname ("eth0" on Linux, for
              example).  This is only defined and needed for IPv6 link-local
              addresses.

       -b n   Allow a backlog of approximately n pending connections.

       -o     Leave IP options alone. If the client is sending packets along
              an IP source route, send packets back along the same route.

       -O     (Default.) Kill IP options.  A client can still use source
              routing to connect and to send data, but packets will be sent
              back along the default route.

       -d     Delay sending data for a fraction of a second whenever the
              remote host is responding slowly. This is currently the default,
              but it may not be in the future; if you want it, set it
              explicitly.

       -D     Never delay sending data; enable TCP_NODELAY.

       -t n   Give up on the $SSLREMOTEINFO connection attempt after n
       -N     (Default.) Setup the SSL environment immediately.

       -s     Store client and server certificate information in the
              environment, a la mod_ssl.

       -S     (Default.) Do not store client and server certificate
              information in the environment.


       X509 certificate and encryption options:

       -3     Read a null-terminated key password from file descriptor 3.

       -m     (Mail.) Require valid client certificates, but don't check for
              matching FQDN.

       -z     (Host.) Require valid client certificates and match FQDN (if
              given) against SAN/DN.

       -Z     (Default.) Do not require client certificates.


       Data-gathering options:

       -h     (Default.) Look up the remote host name in DNS to set the
              environment variable $SSLREMOTEHOST.  In this case, additionally
              the CN/SAN in the X509 certificate can be checked, provided, the
              option -z is set.

       -H     Do not look up the remote host name in DNS; remove the
              environment variable $SSLREMOTEHOST.  To avoid loops, you must
              use this option for servers on TCP port 53.

       -p     Paranoid. After looking up the remote host name in DNS, look up
              the IP addresses in DNS for that host name, and remove the
              environment variable  $SSLREMOTEHOST if none of the addresses
              match the client's IP address.

       -P     (Default.) Not paranoid.

       -l localname
              Do not look up the local host name in DNS; use localname for the
              environment variable $SSLLOCALHOST.  A common choice for
              localname is 0. To avoid loops, you must use this option for
              servers on TCP port 53.

       -r     Attempt to obtain $SSLREMOTEINFO from the remote host.

       -R     (Default.) Do not attempt to obtain $SSLREMOTEINFO from the
              remote host.  To avoid loops, you must use this option for
              servers on TCP ports 53 and 113.

       or alternatively the environment variable $DNSREWRITEFILE points to a
       differnent file.


SSL ENVIRONMENT VARIABLES READ

       These variables define the run-time environment of sslserver and are
       used to specify X509 certificates and keyfile per connection.
       $SSL_USER=name The user, reading the certificates and keyfile.

       $SSL_GROUP=group
              The respective user group.

       $SSL_UID=uid
              The numerical UID of the $SSL_USER.

       $SSL_CHROOT=path
              Perform reading of certificates and keyfile in a $SSL_CHROOT
              jail.

       $CAFILE=path
              If set, overrides the compiled-in CA file name.  The CA file
              contains the list of CAs used to verify the client certificate.
              Certificates in $CAFILE are processed when the server starts.

       $CADIR=path
              If set, overrides the compiled-in CA directory name.  The CA
              directory contains certificates files used to verify the client
              certificate.  This list augments the list from $CAFILE.
              Certificates in $CADIR are processed during certificate
              verification.

       $CERTFILE=path
              If set, overrides the compiled-in certificate file name.  The
              server presents this certificate to clients.

       $CERTCHAINFILE=path
              If set, overrides the compiled-in certificate chainfile name.
              The server presents this list of certificats to clients.  Note:
              Providing $CERTCHAINFILE has precedence over $CERTFILE.
              Certificates in this file needs to be 'ordered' starting from
              the uppermost root certificates and placing your host's
              certificate at the end.

       $CIPHERS=string
              If set, override the compiled-in SSL cipher list defining the
              security level for the connection.  A typical choice would be
              'TLSv1+HIGH:!SSLv2:!MD5'.

       $DHFILE=path
              If set, overrides the compiled-in DH parameter file name.

       $KEYFILE=path
              If set, overrides the compiled-in key file name.  The key is
              connection base) the client certificate request.

       $CCAVERIFY
              If set, sslserver requests a valid client certificate on a per-
              connection base, unlike the general option -z.


SSL ENVIRONMENT VARAIBLES SET

       In case sslserver is called with the option -e, the following mod_ssl
       environment variables are provided:

       SSL_PROTOCOL
              The TLS protocol version (SSLv3, TLSv1, ...).

       SSL_SESSION_ID
              The hex-encoded SSL session id.

       SSL_CIPHER
              The cipher specification name.

       SSL_CIPHER_USEKEYSIZE
              Number of cipher bits (actually used).

       SSL_CIPHER_ALGKEYSIZE
              Number of cipher bits (possible).

       SSL_VERSION_INTERFACE
              The mod_ssl program version.

       SSL_VERSION_LIBRARY
              The OpenSSL program version.

       SSL_CLIENT_M_VERSION
              The version of the client certificate.

       SSL_CLIENT_M_SERIAL
              The serial of the client certificate.

       SSL_CLIENT_S_DN
              Subject DN in client's certificate.

       SSL_CLIENT_S_DN_x509
              Component of client's Subject DN.

       SSL_CLIENT_I_DN
              Issuer DN of client's certificate.

       SSL_CLIENT_I_DN_x509
              Component of client's Issuer DN.

       SSL_CLIENT_V_START
              Validity of client's certificate (start time).


       SSL_CLIENT_VERIFY
              NONE, SUCCESS, GENEROUS or FAILED:reason.

       SSL_SERVER_M_SERIAL
              The serial of the server certificate.

       SSL_SERVER_S_DN
              Subject DN in server's certificate.

       SSL_SERVER_S_DN_x509
              Component of server's Subject DN.

       SSL_SERVER_I_DN
              Issuer DN of server's certificate.

       SSL_SERVER_I_DN_x509
              Component of server's Issuer DN.

       SSL_SERVER_V_START
              Validity of server's certificate (start time).

       SSL_SERVER_V_END
              Validity of server's certificate (end time).

       SSL_SERVER_A_SIG
              Algorithm used for the signature of server's certificate.

       SSL_SERVER_A_KEY
              Algorithm used for the public key of server's certificate.

       SSL_SERVER_CERT
              PEM-encoded server certificate.

       For $SSL_CLIENT_x_DN_x509 and $SSL_SERVER_x_DN_x509, x509 denotes a
       component of the DN: C, ST, L, O, OU, CN, T, I, G, S, D, UID, Email.


       Other SSL environment variables set:

       PROTO, SSLLOCALHOST, SSLLOCALIP, SSLLOCALPORT, SSLREMOTEHOST,
       SSLREMOTEINFO, SSLREMOTEIP, SSLREMOTEPORT.


       TCP environment variables set:

       TCPLOCALHOST, TCPLOCALIP, TCPLOCALPORT, TCPREMOTEHOST, TCPREMOTEINFO,
       TCPREMOTEIP, TCPREMOTEPORT.


       TCP6 environment variables set:

       TCP6INTERFACE, TCP6LOCALHOST, TCP6LOCALIP, TCP6LOCALPORT,
       TCP6REMOTEHOST, TCP6REMOTEIP, TCP6REMOTEPORT.

LOGGING AND ERROR MESSAGES


       sslserver prints information about individual connections in case -v or
       -V is specified as argument.  TLS error messages are provided if
       possible:

	   unable to speak TLS for pid: ... DH lib
	               TLS handshake failure.

	   unable to accept TLS for pid: ...
	               The remote socket was prematurely closed.
       

SEE ALSO

       sslclient(1), sslconnect(1), sslcat(1), https@(1), ucspi-tls(2),
       tcprules(1), tcprulescheck(1), tcpserver(1), tcp-environ(5)


REFERENCE

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



                                                                  sslserver(1)

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