Miscellaneous Support Functions

These functions include:

• display_status() — Shows the status returned by the last GSS-API function called.

• write_all() — Writes a buffer to a file.

• read_all() — Reads a file into a buffer.

• display_ctx_flags() — Shows in a readable form information about the current context, such as whether confidentiality or mutual authentication is allowed.

• print_token() — Prints out a token's value.

Example A–17 Miscellaneous GSS-API Support Functions

/*
 * Copyright 1994 by OpenVision Technologies, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appears in all copies and
 * that both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of OpenVision not be used
 * in advertising or publicity pertaining to distribution of the software
 * without specific, written prior permission. OpenVision makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#if !defined(lint) && !defined(__CODECENTER__)
static char *rcsid = "$Header: /afs/athena.mit.edu/astaff/project/krbdev/.cvsroot
/src/appl/gss-sample/gss-misc.c,v 1.15 1996/07/22 20:21:20 marc Exp $";
#endif

#include <stdio.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <errno.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>

#include <gssapi/gssapi.h>
#include "gss-misc.h"
#include <stdlib.h>

FILE *display_file;
extern gss_OID g_mechOid;


static void display_status_1(char *m, OM_uint32 code, int type);

static int write_all(int fildes, char *buf, unsigned int nbyte)
{
     int ret;
     char *ptr;

     for (ptr = buf; nbyte; ptr += ret, nbyte -= ret) {
          ret = write(fildes, ptr, nbyte);
          if (ret < 0) {
               if (errno == EINTR)
                    continue;
               return(ret);
          } else if (ret == 0) {
               return(ptr-buf);
          }
     }

     return(ptr-buf);
}

static int read_all(int fildes, char *buf, unsigned int nbyte)
{
     int ret;
     char *ptr;

     for (ptr = buf; nbyte; ptr += ret, nbyte -= ret) {
          ret = read(fildes, ptr, nbyte);
          if (ret < 0) {
               if (errno == EINTR)
                    continue;
               return(ret);
          } else if (ret == 0) {
               return(ptr-buf);
          }
     }

     return(ptr-buf);
}

static void display_status_1(m, code, type)
     char *m;
     OM_uint32 code;
     int type;
{
     OM_uint32 maj_stat, min_stat;
     gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
     OM_uint32 msg_ctx;

     msg_ctx = 0;
     while (1) {
          maj_stat = gss_display_status(&min_stat, code,
                                       type, g_mechOid,
                                       &msg_ctx, &msg);
          if (maj_stat != GSS_S_COMPLETE) {
                  if (display_file) {
                        fprintf(display_file, "error in gss_display_status"
                                        " called from <%s>\n", m);
                  }
                  break;
          }
          else if (display_file)
                fprintf(display_file, "GSS-API error %s: %s\n", m,
                      (char *)msg.value);
          if (msg.length != 0)
                (void) gss_release_buffer(&min_stat, &msg);

          if (!msg_ctx)
               break;
     }
}

/*
 * Function: display_status
 *
 * Purpose: displays GSS-API messages
 *
 * Arguments:
 *
 *      msg             a string to be displayed with the message
 *      maj_stat        the GSS-API major status code
 *      min_stat        the GSS-API minor status code
 *
 * Effects:
 *
 * The GSS-API messages associated with maj_stat and min_stat are
 * displayed on stderr, each preceeded by "GSS-API error <msg>:
" and
 * followed by a newline.
 */
void display_status(msg, maj_stat, min_stat)
     char *msg;
     OM_uint32 maj_stat;
     OM_uint32 min_stat;
{
     display_status_1(msg, maj_stat, GSS_C_GSS_CODE);
     display_status_1(msg, min_stat, GSS_C_MECH_CODE);
}


/*
 * Function: display_ctx_flags
 *
 * Purpose: displays the flags returned by context initation in
 *          a human-readable form
 *
 * Arguments:
 *
 *      int             ret_flags
 *
 * Effects:
 *
 * Strings corresponding to the context flags are printed on
 * stdout, preceded by "context flag: " and followed by a newline
 */

void display_ctx_flags(flags)
     OM_uint32 flags;
{
     if (flags & GSS_C_DELEG_FLAG)
          fprintf(display_file, "context flag: GSS_C_DELEG_FLAG\n");
     if (flags & GSS_C_MUTUAL_FLAG)
          fprintf(display_file, "context flag: GSS_C_MUTUAL_FLAG\n");
     if (flags & GSS_C_REPLAY_FLAG)
          fprintf(display_file, "context flag: GSS_C_REPLAY_FLAG\n");
     if (flags & GSS_C_SEQUENCE_FLAG)
          fprintf(display_file, "context flag: GSS_C_SEQUENCE_FLAG\n");
     if (flags & GSS_C_CONF_FLAG )
          fprintf(display_file, "context flag: GSS_C_CONF_FLAG \n");
     if (flags & GSS_C_INTEG_FLAG )
          fprintf(display_file, "context flag: GSS_C_INTEG_FLAG \n");
}

void print_token(tok)
     gss_buffer_t tok;
{
    int i;
    unsigned char *p = tok->value;

    if (!display_file)
        return;
    for (i=0; i < tok->length; i++, p++) {
        fprintf(display_file, "%02x ", *p);
        if ((i % 16) == 15) {
            fprintf(display_file, "\n");
        }
    }
    fprintf(display_file, "\n");
    fflush(display_file);
}