NAME

       gss_unwrap - API function

SYNOPSIS

       #include <gss.h>

       OM_uint32  gss_unwrap(OM_uint32  *  minor_status, const gss_ctx_id_t context_handle, const
       gss_buffer_t input_message_buffer, gss_buffer_t output_message_buffer, int  *  conf_state,
       gss_qop_t * qop_state);

ARGUMENTS

       OM_uint32 * minor_status
                   (Integer, modify) Mechanism specific status code.

       const gss_ctx_id_t context_handle
                   (gss_ctx_id_t, read) Identifies the context on
                     which the message arrived.

       const gss_buffer_t input_message_buffer
                   (buffer, opaque, read) Protected message.

       gss_buffer_t output_message_buffer
                   (buffer, opaque, modify) Buffer to receive
                     unwrapped message.  Storage associated with this buffer must be
                     freed by the application after use use with a call to
                     gss_release_buffer().

       int * conf_state
                   (boolean, modify, optional) Non-zero - Confidentiality
                     and integrity protection were used. Zero - Integrity service only
                     was used.  Specify NULL if not required.

       gss_qop_t * qop_state
                   (gss_qop_t, modify, optional) Quality of protection
                     provided.  Specify NULL if not required.

DESCRIPTION

       Converts  a  message previously protected by gss_wrap back to a usable form, verifying the
       embedded MIC.  The conf_state parameter indicates whether the message was  encrypted;  the
       qop_state  parameter  indicates  the  strength  of protection that was used to provide the
       confidentiality and integrity services.

       Since some application-level protocols may wish to use tokens  emitted  by  gss_wrap()  to
       provide  "secure  framing",  implementations  must  support the wrapping and unwrapping of
       zero-length messages.

RETURN VALUE

       `GSS_S_COMPLETE`: Successful completion.

       `GSS_S_DEFECTIVE_TOKEN`: The token failed consistency checks.

       `GSS_S_BAD_SIG`: The MIC was incorrect.

       `GSS_S_DUPLICATE_TOKEN`: The token was valid, and contained a
        correct MIC for the message, but it had already been processed.

       `GSS_S_OLD_TOKEN`: The token was valid, and contained a correct MIC for the  message,  but
       it is too old to check for duplication.

       `GSS_S_UNSEQ_TOKEN`: The token was valid, and contained a correct MIC for the message, but
       has been verified out of sequence; a later token has already been received.

       `GSS_S_GAP_TOKEN`: The token was valid, and contained a correct MIC for the  message,  but
       has been verified out of sequence; an earlier expected token has not yet been received.

       `GSS_S_CONTEXT_EXPIRED`: The context has already expired.

       `GSS_S_NO_CONTEXT`: The context_handle parameter did not identify a valid context.

REPORTING BUGS

       Report   bugs   to   <bug-gss@gnu.org>.    GNU   Generic   Security   Service  home  page:
       http://www.gnu.org/software/gss/      General      help      using      GNU      software:
       http://www.gnu.org/gethelp/

COPYRIGHT

       Copyright © 2003-2013 Simon Josefsson.
       Copying  and distribution of this file, with or without modification, are permitted in any
       medium without royalty provided the copyright notice and this notice are preserved.

SEE ALSO

       The full documentation for gss is maintained as a Texinfo manual.  If  the  info  and  gss
       programs are properly installed at your site, the command

              info gss

       should give you access to the complete manual.