Solaris 开发者安全性指南

服务器端应用程序

以下示例提供了服务器端程序 gss_server 的源代码。


注 –

此示例的源代码也可以通过 Sun 下载中心获得。请访问 http://www.sun.com/download/products.xml?id=41912db5



示例 A–2 gss-server.c 样例程序的完整代码

/*

 * 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: /cvs/krbdev/krb5/src/appl/gss-sample/gss-server.c, \

    v 1.21 1998/12/22 \

04:10:08 tytso Exp $";

#endif



#include <stdio.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/time.h>

#include <netinet/in.h>

#include <unistd.h>

#include <stdlib.h>

#include <ctype.h>



#include <gssapi/gssapi.h>

#include <gssapi/gssapi_ext.h>

#include <gss-misc.h>



#include <string.h>



void usage()

{

     fprintf(stderr, "Usage: gss-server [-port port] [-verbose]\n");

     fprintf(stderr, "       [-inetd] [-logfile file] [service_name]\n");

     exit(1);

}



FILE *log;



int verbose = 0;



/*

 * Function: server_acquire_creds

 *

 * Purpose: imports a service name and acquires credentials for it

 *

 * Arguments:

 *

 *      service_name    (r) the ASCII service name

 *      server_creds    (w) the GSS-API service credentials

 *

 * Returns: 0 on success, -1 on failure

 *

 * Effects:

 *

 * The service name is imported with gss_import_name, and service

 * credentials are acquired with gss_acquire_cred.  If either operation

 * fails, an error message is displayed and -1 is returned; otherwise,

 * 0 is returned.

 */

int server_acquire_creds(service_name, server_creds)

     char *service_name;

     gss_cred_id_t *server_creds;

{

     gss_buffer_desc name_buf;

     gss_name_t server_name;

     OM_uint32 maj_stat, min_stat;



     name_buf.value = service_name;

     name_buf.length = strlen(name_buf.value) + 1;

     maj_stat = gss_import_name(&min_stat, &name_buf, 

         (gss_OID) GSS_C_NT_HOSTBASED_SERVICE, &server_name);

     if (maj_stat != GSS_S_COMPLETE) {

         display_status("importing name", maj_stat, min_stat);

         return -1;

     }



     maj_stat = gss_acquire_cred(&min_stat, server_name, 0,

                                 GSS_C_NULL_OID_SET, GSS_C_ACCEPT,

                                 server_creds, NULL, NULL);

     if (maj_stat != GSS_S_COMPLETE) {

          display_status("acquiring credentials", maj_stat, min_stat);

          return -1;

     }



     (void) gss_release_name(&min_stat, &server_name);



     return 0;

}



/*

 * Function: server_establish_context

 *

 * Purpose: establishes a GSS-API context as a specified service with

 * an incoming client, and returns the context handle and associated

 * client name

 *

 * Arguments:

 *

 *      s               (r) an established TCP connection to the client

 *      service_creds   (r) server credentials, from gss_acquire_cred

 *      context         (w) the established GSS-API context

 *      client_name     (w) the client's ASCII name

 *

 * Returns: 0 on success, -1 on failure

 *

 * Effects:

 *

 * Any valid client request is accepted.  If a context is established,

 * its handle is returned in context and the client name is returned

 * in client_name and 0 is returned.  If unsuccessful, an error

 * message is displayed and -1 is returned.

 */

int server_establish_context(s, server_creds, context, client_name, \

     ret_flags)



     int s;

     gss_cred_id_t server_creds;

     gss_ctx_id_t *context;

     gss_buffer_t client_name;

     OM_uint32 *ret_flags;

{

     gss_buffer_desc send_tok, recv_tok;

     gss_name_t client;

     gss_OID doid;

     OM_uint32 maj_stat, min_stat, acc_sec_min_stat;

     gss_buffer_desc    oid_name;



     *context = GSS_C_NO_CONTEXT;

     

     do {

          if (recv_token(s, &recv_tok) < 0)

               return -1;



          if (verbose && log) {

              fprintf(log, "Received token (size=%d): \n", recv_tok.length);

              print_token(&recv_tok);

          }



          maj_stat =

               gss_accept_sec_context(&acc_sec_min_stat,

                                      context,

                                      server_creds,

                                      &recv_tok,

                                      GSS_C_NO_CHANNEL_BINDINGS,

                                      &client,

                                      &doid,

                                      &send_tok,

                                      ret_flags,

                                      NULL,     /* ignore time_rec */

                                      NULL);    /* ignore del_cred_handle */



          (void) gss_release_buffer(&min_stat, &recv_tok);



          if (send_tok.length != 0) {

              if (verbose && log) {

                  fprintf(log,

                          "Sending accept_sec_context token (size=%d):\n",

                          send_tok.length);

                  print_token(&send_tok);

              }

               if (send_token(s, &send_tok) < 0) {

                    fprintf(log, "failure sending token\n");

                    return -1;

               }



               (void) gss_release_buffer(&min_stat, &send_tok);

          }

          if (maj_stat!=GSS_S_COMPLETE && maj_stat!=GSS_S_CONTINUE_NEEDED) {

               display_status("accepting context", maj_stat,

                              acc_sec_min_stat);

               if (*context == GSS_C_NO_CONTEXT)

                       gss_delete_sec_context(&min_stat, context,

                                              GSS_C_NO_BUFFER);

               return -1;

          }



          if (verbose && log) {

              if (maj_stat == GSS_S_CONTINUE_NEEDED)

                  fprintf(log, "continue needed...\n");

              else

                  fprintf(log, "\n");

              fflush(log);

          }

     } while (maj_stat == GSS_S_CONTINUE_NEEDED);



     /* display the flags */

     display_ctx_flags(*ret_flags);



     if (verbose && log) {

         maj_stat = gss_oid_to_str(&min_stat, doid, &oid_name);

         if (maj_stat != GSS_S_COMPLETE) {

             display_status("converting oid->string", maj_stat, min_stat);

             return -1;

         }

         fprintf(log, "Accepted connection using mechanism OID %.*s.\n",

                 (int) oid_name.length, (char *) oid_name.value);

         (void) gss_release_buffer(&min_stat, &oid_name);

     }



     maj_stat = gss_display_name(&min_stat, client, client_name, &doid);

     if (maj_stat != GSS_S_COMPLETE) {

          display_status("displaying name", maj_stat, min_stat);

          return -1;

     }

     maj_stat = gss_release_name(&min_stat, &client);

     if (maj_stat != GSS_S_COMPLETE) {

          display_status("releasing name", maj_stat, min_stat);

          return -1;

     }

     return 0;

}



/*

 * Function: create_socket

 *

 * Purpose: Opens a listening TCP socket.

 *

 * Arguments:

 *

 *      port            (r) the port number on which to listen

 *

 * Returns: the listening socket file descriptor, or -1 on failure

 *

 * Effects:

 *

 * A listening socket on the specified port is created and returned.

 * On error, an error message is displayed and -1 is returned.

 */

int create_socket(port)

     u_short port;

{

     struct sockaddr_in saddr;

     int s;

     int on = 1;

     

     saddr.sin_family = AF_INET;

     saddr.sin_port = htons(port);

     saddr.sin_addr.s_addr = INADDR_ANY;



     if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) {

          perror("creating socket");

          return -1;

     }

     /* Let the socket be reused right away */

     (void) setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&on, 

          sizeof(on));

     if (bind(s, (struct sockaddr *) &saddr, sizeof(saddr)) < 0) {

          perror("binding socket");

          (void) close(s);

          return -1;

     }

     if (listen(s, 5) < 0) {

          perror("listening on socket");

          (void) close(s);

          return -1;

     }

     return s;

}



static float timeval_subtract(tv1, tv2)

        struct timeval *tv1, *tv2;

{

        return ((tv1->tv_sec - tv2->tv_sec) +

                ((float) (tv1->tv_usec - tv2->tv_usec)) / 1000000);

}



/*

 * Yes, yes, this isn't the best place for doing this test.

 * DO NOT REMOVE THIS UNTIL A BETTER TEST HAS BEEN WRITTEN, THOUGH.

 *                                      -TYT

 */

int test_import_export_context(context)

        gss_ctx_id_t *context;

{

        OM_uint32       min_stat, maj_stat;

        gss_buffer_desc context_token, copied_token;

        struct timeval tm1, tm2;



        /*

         * Attempt to save and then restore the context.

         */

        gettimeofday(&tm1, (struct timezone *)0);

        maj_stat = gss_export_sec_context(&min_stat, context, \

            &context_token);

        if (maj_stat != GSS_S_COMPLETE) {

                display_status("exporting context", maj_stat, min_stat);

                return 1;

        }

        gettimeofday(&tm2, (struct timezone *)0);

        if (verbose && log)

                fprintf(log, "Exported context: %d bytes, %7.4f seconds\n",

                        context_token.length, timeval_subtract(&tm2, &tm1));

        copied_token.length = context_token.length;

        copied_token.value = malloc(context_token.length);

        if (copied_token.value == 0) {

            fprintf(log, "Couldn't allocate memory to copy context \

                token.\n");

            return 1;

        }

        memcpy(copied_token.value, context_token.value, \

            copied_token.length);

        maj_stat = gss_import_sec_context(&min_stat, &copied_token, \

            context);

        if (maj_stat != GSS_S_COMPLETE) {

                display_status("importing context", maj_stat, min_stat);

                return 1;

        }

        free(copied_token.value);

        gettimeofday(&tm1, (struct timezone *)0);

        if (verbose && log)

                fprintf(log, "Importing context: %7.4f seconds\n",

                        timeval_subtract(&tm1, &tm2));

        (void) gss_release_buffer(&min_stat, &context_token);

        return 0;

}



/*

 * Function: sign_server

 *

 * Purpose: Performs the "sign" service.

 *

 * Arguments:

 *

 *      s               (r) a TCP socket on which a connection has been

 *                      accept()ed

 *      service_name    (r) the ASCII name of the GSS-API service to

 *                      establish a context as

 * 

 * Returns: -1 on error

 *

 * Effects:

 *

 * sign_server establishes a context, and performs a single sign request.

 *

 * A sign request is a single GSS-API sealed token.  The token is

 * unsealed and a signature block, produced with gss_sign, is returned

 * to the sender.  The context is then destroyed and the connection

 * closed.

 *

 * If any error occurs, -1 is returned.

 */

int sign_server(s, server_creds)

     int s;

     gss_cred_id_t server_creds;

{

     gss_buffer_desc client_name, xmit_buf, msg_buf;

     gss_ctx_id_t context;

     OM_uint32 maj_stat, min_stat;

     int i, conf_state, ret_flags;

     char       *cp;

     

     /* Establish a context with the client */

     if (server_establish_context(s, server_creds, &context,

                                  &client_name, &ret_flags) < 0)

        return(-1);

          

     printf("Accepted connection: \"%.*s\"\n",

            (int) client_name.length, (char *) client_name.value);

     (void) gss_release_buffer(&min_stat, &client_name);



     for (i=0; i < 3; i++)

             if (test_import_export_context(&context))

                     return -1;



     /* Receive the sealed message token */

     if (recv_token(s, &xmit_buf) < 0)

        return(-1);

          

     if (verbose && log) {

        fprintf(log, "Sealed message token:\n");

        print_token(&xmit_buf);

     }



     maj_stat = gss_unwrap(&min_stat, context, &xmit_buf, &msg_buf,

                           &conf_state, (gss_qop_t *) NULL);

     if (maj_stat != GSS_S_COMPLETE) {

        display_status("unsealing message", maj_stat, min_stat);

        return(-1);

     } else if (! conf_state) {

        fprintf(stderr, "Warning!  Message not encrypted.\n");

     }



     (void) gss_release_buffer(&min_stat, &xmit_buf);



     fprintf(log, "Received message: ");

     cp = msg_buf.value;

     if ((isprint(cp[0]) || isspace(cp[0])) &&

         (isprint(cp[1]) || isspace(cp[1]))) {

        fprintf(log, "\"%.*s\"\n", msg_buf.length, msg_buf.value);

     } else {

        printf("\n");

        print_token(&msg_buf);

     }

          

     /* Produce a signature block for the message */

     maj_stat = gss_get_mic(&min_stat, context, GSS_C_QOP_DEFAULT,

                            &msg_buf, &xmit_buf);

     if (maj_stat != GSS_S_COMPLETE) {

        display_status("signing message", maj_stat, min_stat);

        return(-1);

     }



     (void) gss_release_buffer(&min_stat, &msg_buf);



     /* Send the signature block to the client */

     if (send_token(s, &xmit_buf) < 0)

        return(-1);



     (void) gss_release_buffer(&min_stat, &xmit_buf);



     /* Delete context */

     maj_stat = gss_delete_sec_context(&min_stat, &context, NULL);

     if (maj_stat != GSS_S_COMPLETE) {

        display_status("deleting context", maj_stat, min_stat);

        return(-1);

     }



     fflush(log);



     return(0);

}



int

main(argc, argv)

     int argc;

     char **argv;

{

     char *service_name;

     gss_cred_id_t server_creds;

     OM_uint32 min_stat;

     u_short port = 4444;

     int s;

     int once = 0;

     int do_inetd = 0;



     log = stdout;

     display_file = stdout;

     argc--; argv++;

     while (argc) {

          if (strcmp(*argv, "-port") == 0) {

               argc--; argv++;

               if (!argc) usage();

               port = atoi(*argv);

          } else if (strcmp(*argv, "-verbose") == 0) {

              verbose = 1;

          } else if (strcmp(*argv, "-once") == 0) {

              once = 1;

          } else if (strcmp(*argv, "-inetd") == 0) {

              do_inetd = 1;

          } else if (strcmp(*argv, "-logfile") == 0) {

              argc--; argv++;

              if (!argc) usage();

              log = fopen(*argv, "a");

              display_file = log;

              if (!log) {

                  perror(*argv);

                  exit(1);

              }

          } else

               break;

          argc--; argv++;

     }

     if (argc != 1)

          usage();



     if ((*argv)[0] == '-')

          usage();



     service_name = *argv;



     if (server_acquire_creds(service_name, &server_creds) < 0)

         return -1;

     

     if (do_inetd) {

         close(1);

         close(2);



         sign_server(0, server_creds);

         close(0);

     } else {

         int stmp;



         if ((stmp = create_socket(port)) >= 0) {

             do {

                 /* Accept a TCP connection */

                 if ((s = accept(stmp, NULL, 0)) < 0) {

                     perror("accepting connection");

                     continue;

                 }

                 /* this return value is not checked, because there's

                    not really anything to do if it fails */

                 sign_server(s, server_creds);

                 close(s);

             } while (!once);



             close(stmp);

         }

     }



     (void) gss_release_cred(&min_stat, &server_creds);



     /*NOTREACHED*/

     (void) close(s);

     return 0;

}