/*-
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Copyright (C) 1990 by the Massachusetts Institute of Technology
 *
 * Export of this software from the United States of America may
 * require a specific license from the United States Government.
 * It is the responsibility of any person or organization contemplating
 * export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 */

#include <config.h>

RCSID("$Id$");

#ifdef  KRB5

#include <arpa/telnet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>
#include <ctype.h>
#include <pwd.h>
#define Authenticator k5_Authenticator
#include <krb5.h>
#undef Authenticator
#include <roken.h>
#ifdef SOCKS
#include <socks.h>
#endif


#include "encrypt.h"
#include "auth.h"
#include "misc.h"

#if defined(DCE)
int dfsk5ok = 0;
int dfspag = 0;
int dfsfwd = 0;
#endif

int forward_flags = 0;  /* Flags get set in telnet/main.c on -f and -F */

int forward(int);
int forwardable(int);

/* These values need to be the same as those defined in telnet/main.c. */
/* Either define them in both places, or put in some common header file. */
#define OPTS_FORWARD_CREDS      0x00000002
#define OPTS_FORWARDABLE_CREDS  0x00000001


void kerberos5_forward (Authenticator *);

static unsigned char str_data[4] = { IAC, SB, TELOPT_AUTHENTICATION, 0 };

#define KRB_AUTH                0       /* Authentication data follows */
#define KRB_REJECT              1       /* Rejected (reason might follow) */
#define KRB_ACCEPT              2       /* Accepted */
#define KRB_RESPONSE            3       /* Response for mutual auth. */

#define KRB_FORWARD             4       /* Forwarded credentials follow */
#define KRB_FORWARD_ACCEPT      5       /* Forwarded credentials accepted */
#define KRB_FORWARD_REJECT      6       /* Forwarded credentials rejected */

static  krb5_data auth;
static  krb5_ticket *ticket;

static krb5_context context;
static krb5_auth_context auth_context;

static int
Data(Authenticator *ap, int type, const void *d, int c)
{
    const unsigned char *cp, *cd = d;
    unsigned char *p0, *p;
    size_t len = sizeof(str_data) + 3 + 2;
    int ret;

    if (c == -1)
        c = strlen((const char*)cd);

    for (cp = cd; cp - cd < c; cp++, len++)
        if (*cp == IAC)
            len++;

    p0 = malloc(len);
    if (p0 == NULL)
        return 0;

    memcpy(p0, str_data, sizeof(str_data));
    p = p0 + sizeof(str_data);

    if (auth_debug_mode) {
        printf("%s:%d: [%d] (%d)",
               str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
               str_data[3],
               type, c);
        printd(d, c);
        printf("\r\n");
    }
    *p++ = ap->type;
    *p++ = ap->way;
    *p++ = type;
    while (c-- > 0) {
        if ((*p++ = *cd++) == IAC)
            *p++ = IAC;
    }
    *p++ = IAC;
    *p++ = SE;
    if (str_data[3] == TELQUAL_IS)
        printsub('>', &p0[2], len - 2);
    ret = telnet_net_write(p0, len);
    free(p0);
    return ret;
}

int
kerberos5_init(Authenticator *ap, int server)
{
    krb5_error_code ret;

    ret = krb5_init_context(&context);
    if (ret)
        return 0;
    if (server) {
        krb5_keytab kt;
        krb5_kt_cursor cursor;

        ret = krb5_kt_default(context, &kt);
        if (ret)
            return 0;

        ret = krb5_kt_start_seq_get (context, kt, &cursor);
        if (ret) {
            krb5_kt_close (context, kt);
            return 0;
        }
        krb5_kt_end_seq_get (context, kt, &cursor);
        krb5_kt_close (context, kt);

        str_data[3] = TELQUAL_REPLY;
    } else
        str_data[3] = TELQUAL_IS;
    return(1);
}

extern int net;
static int
kerberos5_send(char *name, Authenticator *ap)
{
    krb5_error_code ret;
    krb5_ccache ccache;
    int ap_opts;
    krb5_data cksum_data;
    char ap_msg[2];

    if (!UserNameRequested) {
        if (auth_debug_mode) {
            printf("Kerberos V5: no user name supplied\r\n");
        }
        return(0);
    }

    ret = krb5_cc_default(context, &ccache);
    if (ret) {
        if (auth_debug_mode) {
            printf("Kerberos V5: could not get default ccache: %s\r\n",
                   krb5_get_err_text (context, ret));
        }
        return 0;
    }

    if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL)
        ap_opts = AP_OPTS_MUTUAL_REQUIRED;
    else
        ap_opts = 0;

    ap_opts |= AP_OPTS_USE_SUBKEY;

    ret = krb5_auth_con_init (context, &auth_context);
    if (ret) {
        if (auth_debug_mode) {
            printf("Kerberos V5: krb5_auth_con_init failed (%s)\r\n",
                   krb5_get_err_text(context, ret));
        }
        return(0);
    }

    ret = krb5_auth_con_setaddrs_from_fd (context,
                                          auth_context,
                                          &net);
    if (ret) {
        if (auth_debug_mode) {
            printf ("Kerberos V5:"
                    " krb5_auth_con_setaddrs_from_fd failed (%s)\r\n",
                    krb5_get_err_text(context, ret));
        }
        return(0);
    }

    krb5_auth_con_setkeytype (context, auth_context, KRB5_ENCTYPE_DES_CBC_CRC);

    ap_msg[0] = ap->type;
    ap_msg[1] = ap->way;

    cksum_data.length = sizeof(ap_msg);
    cksum_data.data   = ap_msg;


    {
        krb5_principal service;
        char sname[128];


        ret = krb5_sname_to_principal (context,
                                       RemoteHostName,
                                       NULL,
                                       KRB5_NT_SRV_HST,
                                       &service);
        if(ret) {
            if (auth_debug_mode) {
                printf ("Kerberos V5:"
                        " krb5_sname_to_principal(%s) failed (%s)\r\n",
                        RemoteHostName, krb5_get_err_text(context, ret));
            }
            return 0;
        }
        ret = krb5_unparse_name_fixed(context, service, sname, sizeof(sname));
        if(ret) {
            if (auth_debug_mode) {
                printf ("Kerberos V5:"
                        " krb5_unparse_name_fixed failed (%s)\r\n",
                        krb5_get_err_text(context, ret));
            }
            return 0;
        }
        printf("[ Trying %s (%s)... ]\r\n", name, sname);
        ret = krb5_mk_req_exact(context, &auth_context, ap_opts,
                                service,
                                &cksum_data, ccache, &auth);
        krb5_free_principal (context, service);

    }
    if (ret) {
        if (1 || auth_debug_mode) {
            printf("Kerberos V5: mk_req failed (%s)\r\n",
                   krb5_get_err_text(context, ret));
        }
        return(0);
    }

    if (!auth_sendname((unsigned char *)UserNameRequested,
                       strlen(UserNameRequested))) {
        if (auth_debug_mode)
            printf("Not enough room for user name\r\n");
        return(0);
    }
    if (!Data(ap, KRB_AUTH, auth.data, auth.length)) {
        if (auth_debug_mode)
            printf("Not enough room for authentication data\r\n");
        return(0);
    }
    if (auth_debug_mode) {
        printf("Sent Kerberos V5 credentials to server\r\n");
    }
    return(1);
}

int
kerberos5_send_mutual(Authenticator *ap)
{
    return kerberos5_send("mutual KERBEROS5", ap);
}

int
kerberos5_send_oneway(Authenticator *ap)
{
    return kerberos5_send("KERBEROS5", ap);
}

static void log_message(const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    if (auth_debug_mode) {
        va_start(ap, fmt);
        vfprintf(stdout, fmt, ap);
        va_end(ap);
        fprintf(stdout, "\r\n");
    }
    va_start(ap, fmt);
    vsyslog(LOG_NOTICE, fmt, ap);
    va_end(ap);
}

void
kerberos5_is(Authenticator *ap, unsigned char *data, int cnt)
{
    krb5_error_code ret;
    krb5_data outbuf;
    krb5_keyblock *key_block;
    char *name;
    krb5_principal server;
    int zero = 0;

    if (cnt-- < 1)
        return;
    switch (*data++) {
    case KRB_AUTH:
        auth.data = (char *)data;
        auth.length = cnt;

        auth_context = NULL;

        ret = krb5_auth_con_init (context, &auth_context);
        if (ret) {
            Data(ap, KRB_REJECT, "krb5_auth_con_init failed", -1);
            auth_finished(ap, AUTH_REJECT);
            log_message("Kerberos V5: krb5_auth_con_init failed (%s)",
                        krb5_get_err_text(context, ret));
            return;
        }

        ret = krb5_auth_con_setaddrs_from_fd (context,
                                              auth_context,
                                              &zero);
        if (ret) {
            Data(ap, KRB_REJECT, "krb5_auth_con_setaddrs_from_fd failed", -1);
            auth_finished(ap, AUTH_REJECT);
            log_message("Kerberos V5: "
                        "krb5_auth_con_setaddrs_from_fd failed (%s)",
                        krb5_get_err_text(context, ret));
            return;
        }

        ret = krb5_sock_to_principal (context,
                                      0,
                                      "host",
                                      KRB5_NT_SRV_HST,
                                      &server);
        if (ret) {
            Data(ap, KRB_REJECT, "krb5_sock_to_principal failed", -1);
            auth_finished(ap, AUTH_REJECT);
            log_message("Kerberos V5: "
                        "krb5_sock_to_principal failed (%s)",
                        krb5_get_err_text(context, ret));
            return;
        }

        ret = krb5_rd_req(context,
                          &auth_context,
                          &auth,
                          server,
                          NULL,
                          NULL,
                          &ticket);

        krb5_free_principal (context, server);
        if (ret) {
            const char *errbuf2 = "Read req failed";
            char *errbuf;
            int ret2;

            ret2 = asprintf(&errbuf,
                            "Read req failed: %s",
                            krb5_get_err_text(context, ret));
            if (ret2 != -1)
                errbuf2 = errbuf;
            Data(ap, KRB_REJECT, errbuf2, -1);
            log_message("%s", errbuf2);
            if (ret2 != -1)
                free (errbuf);
            return;
        }

        {
            char ap_msg[2];

            ap_msg[0] = ap->type;
            ap_msg[1] = ap->way;

            ret = krb5_verify_authenticator_checksum(context,
                                                     auth_context,
                                                     ap_msg,
                                                     sizeof(ap_msg));

            if (ret) {
                const char *errbuf2 = "Bad checksum";
                char *errbuf;
                int ret2;

                ret2 = asprintf(&errbuf, "Bad checksum: %s",
                                krb5_get_err_text(context, ret));
                if (ret2 != -1)
                    errbuf2 = errbuf;
                Data(ap, KRB_REJECT, errbuf2, -1);
                log_message("%s", errbuf2);
                if (ret2 != -1)
                    free(errbuf);
                return;
            }
        }
        ret = krb5_auth_con_getremotesubkey (context,
                                             auth_context,
                                             &key_block);

        if (ret) {
            Data(ap, KRB_REJECT, "krb5_auth_con_getremotesubkey failed", -1);
            auth_finished(ap, AUTH_REJECT);
            log_message("Kerberos V5: "
                        "krb5_auth_con_getremotesubkey failed (%s)",
                        krb5_get_err_text(context, ret));
            return;
        }

        if (key_block == NULL) {
            ret = krb5_auth_con_getkey(context,
                                       auth_context,
                                       &key_block);
        }
        if (ret) {
            Data(ap, KRB_REJECT, "krb5_auth_con_getkey failed", -1);
            auth_finished(ap, AUTH_REJECT);
            log_message("Kerberos V5: "
                        "krb5_auth_con_getkey failed (%s)",
                        krb5_get_err_text(context, ret));
            return;
        }
        if (key_block == NULL) {
            Data(ap, KRB_REJECT, "no subkey received", -1);
            auth_finished(ap, AUTH_REJECT);
            log_message("Kerberos V5: "
                        "krb5_auth_con_getremotesubkey returned NULL key");
            return;
        }

        if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
            ret = krb5_mk_rep(context, auth_context, &outbuf);
            if (ret) {
                Data(ap, KRB_REJECT,
                     "krb5_mk_rep failed", -1);
                auth_finished(ap, AUTH_REJECT);
                log_message("Kerberos V5: "
                            "krb5_mk_rep failed (%s)",
                            krb5_get_err_text(context, ret));
                krb5_free_keyblock(context, key_block);
                return;
            }
            Data(ap, KRB_RESPONSE, outbuf.data, outbuf.length);
        }
        if (krb5_unparse_name(context, ticket->client, &name))
            name = 0;

        if(UserNameRequested && krb5_kuserok(context,
                                             ticket->client,
                                             UserNameRequested)) {
            Data(ap, KRB_ACCEPT, name, name ? -1 : 0);
            log_message("%s accepted as user %s from %s",
                        name ? name : "<unknown>",
                        UserNameRequested ? UserNameRequested : "<unknown>",
                        RemoteHostName ? RemoteHostName : "<unknown>");

            if(key_block->keytype == ETYPE_DES_CBC_MD5 ||
               key_block->keytype == ETYPE_DES_CBC_MD4 ||
               key_block->keytype == ETYPE_DES_CBC_CRC) {
                Session_Key skey;

                skey.type = SK_DES;
                skey.length = 8;
                skey.data = key_block->keyvalue.data;
                encrypt_session_key(&skey, 0);
            }

        } else {
            const char *msg2 = "user is not authorized to login";
            char *msg;

            ret = asprintf (&msg, "user `%s' is not authorized to "
                            "login as `%s'",
                            name ? name : "<unknown>",
                            UserNameRequested ? UserNameRequested : "<nobody>");
            if (ret != -1)
                msg2 = msg;
            Data(ap, KRB_REJECT, (void *)msg2, -1);
            if (ret != -1)
                free(msg);
            auth_finished (ap, AUTH_REJECT);
            krb5_free_keyblock(context, key_block);
            break;
        }
        auth_finished(ap, AUTH_USER);
        krb5_free_keyblock(context, key_block);

        break;
    case KRB_FORWARD: {
        struct passwd *pwd;
        char ccname[1024];      /* XXX */
        krb5_data inbuf;
        krb5_ccache ccache;
        inbuf.data = (char *)data;
        inbuf.length = cnt;

        pwd = getpwnam (UserNameRequested);
        if (pwd == NULL)
            break;

        snprintf (ccname, sizeof(ccname),
                  "FILE:/tmp/krb5cc_%lu", (unsigned long)pwd->pw_uid);

        ret = krb5_cc_resolve (context, ccname, &ccache);
        if (ret) {
            log_message("Kerberos V5: could not get ccache: %s",
                        krb5_get_err_text(context, ret));
            break;
        }

        ret = krb5_cc_initialize (context,
                                  ccache,
                                  ticket->client);
        if (ret) {
            log_message("Kerberos V5: could not init ccache: %s",
                        krb5_get_err_text(context, ret));
            break;
        }

#if defined(DCE)
        esetenv("KRB5CCNAME", ccname, 1);
#endif
        ret = krb5_rd_cred2 (context,
                             auth_context,
                             ccache,
                             &inbuf);
        if(ret) {
            const char *errbuf2 = "Read forwarded creds failed";
            char *errbuf;
            int ret2;

            ret2 = asprintf (&errbuf,
                             "Read forwarded creds failed: %s",
                             krb5_get_err_text (context, ret));
            if (ret2 != -1)
                errbuf2 = errbuf;
            Data(ap, KRB_FORWARD_REJECT, errbuf, -1);
            log_message("Could not read forwarded credentials: %s", errbuf);

            if (ret2 != -1)
                free (errbuf);
        } else {
            Data(ap, KRB_FORWARD_ACCEPT, 0, 0);
#if defined(DCE)
            dfsfwd = 1;
#endif
        }
        chown (ccname + 5, pwd->pw_uid, -1);
        log_message("Forwarded credentials obtained");
        break;
    }
    default:
        log_message("Unknown Kerberos option %d", data[-1]);
        Data(ap, KRB_REJECT, 0, 0);
        break;
    }
}

void
kerberos5_reply(Authenticator *ap, unsigned char *data, int cnt)
{
    static int mutual_complete = 0;

    if (cnt-- < 1)
        return;
    switch (*data++) {
    case KRB_REJECT:
        if (cnt > 0) {
            printf("[ Kerberos V5 refuses authentication because %.*s ]\r\n",
                   cnt, data);
        } else
            printf("[ Kerberos V5 refuses authentication ]\r\n");
        auth_send_retry();
        return;
    case KRB_ACCEPT: {
        krb5_error_code ret;
        Session_Key skey;
        krb5_keyblock *keyblock;

        if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL &&
            !mutual_complete) {
            printf("[ Kerberos V5 accepted you, but didn't provide mutual authentication! ]\r\n");
            auth_send_retry();
            return;
        }
        if (cnt)
            printf("[ Kerberos V5 accepts you as ``%.*s'' ]\r\n", cnt, data);
        else
            printf("[ Kerberos V5 accepts you ]\r\n");

        ret = krb5_auth_con_getlocalsubkey (context,
                                            auth_context,
                                            &keyblock);
        if (ret)
            ret = krb5_auth_con_getkey (context,
                                        auth_context,
                                        &keyblock);
        if(ret) {
            printf("[ krb5_auth_con_getkey: %s ]\r\n",
                   krb5_get_err_text(context, ret));
            auth_send_retry();
            return;
        }

        skey.type = SK_DES;
        skey.length = 8;
        skey.data = keyblock->keyvalue.data;
        encrypt_session_key(&skey, 0);
        krb5_free_keyblock (context, keyblock);
        auth_finished(ap, AUTH_USER);
        if (forward_flags & OPTS_FORWARD_CREDS)
            kerberos5_forward(ap);
        break;
    }
    case KRB_RESPONSE:
        if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
            /* the rest of the reply should contain a krb_ap_rep */
          krb5_ap_rep_enc_part *reply;
          krb5_data inbuf;
          krb5_error_code ret;

          inbuf.length = cnt;
          inbuf.data = (char *)data;

          ret = krb5_rd_rep(context, auth_context, &inbuf, &reply);
          if (ret) {
              printf("[ Mutual authentication failed: %s ]\r\n",
                     krb5_get_err_text (context, ret));
              auth_send_retry();
              return;
          }
          krb5_free_ap_rep_enc_part(context, reply);
          mutual_complete = 1;
        }
        return;
    case KRB_FORWARD_ACCEPT:
        printf("[ Kerberos V5 accepted forwarded credentials ]\r\n");
        return;
    case KRB_FORWARD_REJECT:
        printf("[ Kerberos V5 refuses forwarded credentials because %.*s ]\r\n",
               cnt, data);
        return;
    default:
        if (auth_debug_mode)
            printf("Unknown Kerberos option %d\r\n", data[-1]);
        return;
    }
}

int
kerberos5_status(Authenticator *ap, char *name, size_t name_sz, int level)
{
    if (level < AUTH_USER)
        return(level);

    if (UserNameRequested &&
        krb5_kuserok(context,
                     ticket->client,
                     UserNameRequested))
        {
            strlcpy(name, UserNameRequested, name_sz);
#if defined(DCE)
            dfsk5ok = 1;
#endif
            return(AUTH_VALID);
        } else
            return(AUTH_USER);
}

#define BUMP(buf, len)          while (*(buf)) {++(buf), --(len);}
#define ADDC(buf, len, c)       if ((len) > 0) {*(buf)++ = (c); --(len);}

void
kerberos5_printsub(unsigned char *data, size_t cnt,
                   unsigned char *buf, size_t buflen)
{
    int i;

    buf[buflen-1] = '\0';               /* make sure it's NULL terminated */
    buflen -= 1;

    switch(data[3]) {
    case KRB_REJECT:            /* Rejected (reason might follow) */
        strlcpy((char *)buf, " REJECT ", buflen);
        goto common;

    case KRB_ACCEPT:            /* Accepted (name might follow) */
        strlcpy((char *)buf, " ACCEPT ", buflen);
    common:
        BUMP(buf, buflen);
        if (cnt <= 4)
            break;
        ADDC(buf, buflen, '"');
        for (i = 4; i < cnt; i++)
            ADDC(buf, buflen, data[i]);
        ADDC(buf, buflen, '"');
        ADDC(buf, buflen, '\0');
        break;


    case KRB_AUTH:                      /* Authentication data follows */
        strlcpy((char *)buf, " AUTH", buflen);
        goto common2;

    case KRB_RESPONSE:
        strlcpy((char *)buf, " RESPONSE", buflen);
        goto common2;

    case KRB_FORWARD:           /* Forwarded credentials follow */
        strlcpy((char *)buf, " FORWARD", buflen);
        goto common2;

    case KRB_FORWARD_ACCEPT:    /* Forwarded credentials accepted */
        strlcpy((char *)buf, " FORWARD_ACCEPT", buflen);
        goto common2;

    case KRB_FORWARD_REJECT:    /* Forwarded credentials rejected */
        /* (reason might follow) */
        strlcpy((char *)buf, " FORWARD_REJECT", buflen);
        goto common2;

    default:
        snprintf((char*)buf, buflen, " %d (unknown)", data[3]);
    common2:
        BUMP(buf, buflen);
        for (i = 4; i < cnt; i++) {
            snprintf((char*)buf, buflen, " %d", data[i]);
            BUMP(buf, buflen);
        }
        break;
    }
}

void
kerberos5_forward(Authenticator *ap)
{
    krb5_error_code ret;
    krb5_ccache     ccache;
    krb5_creds      creds;
    KDCOptions      flags;
    krb5_data       out_data;
    krb5_principal  principal;

    ret = krb5_cc_default (context, &ccache);
    if (ret) {
        if (auth_debug_mode)
            printf ("KerberosV5: could not get default ccache: %s\r\n",
                    krb5_get_err_text (context, ret));
        return;
    }

    ret = krb5_cc_get_principal (context, ccache, &principal);
    if (ret) {
        if (auth_debug_mode)
            printf ("KerberosV5: could not get principal: %s\r\n",
                    krb5_get_err_text (context, ret));
        return;
    }

    memset (&creds, 0, sizeof(creds));

    creds.client = principal;

    ret = krb5_make_principal(context,
                              &creds.server,
                              principal->realm,
                              "krbtgt",
                              principal->realm,
                              NULL);

    if (ret) {
        if (auth_debug_mode)
            printf ("KerberosV5: could not get principal: %s\r\n",
                    krb5_get_err_text (context, ret));
        return;
    }

    creds.times.endtime = 0;

    memset(&flags, 0, sizeof(flags));
    flags.forwarded = 1;
    if (forward_flags & OPTS_FORWARDABLE_CREDS)
        flags.forwardable = 1;

    ret = krb5_get_forwarded_creds (context,
                                    auth_context,
                                    ccache,
                                    KDCOptions2int(flags),
                                    RemoteHostName,
                                    &creds,
                                    &out_data);
    if (ret) {
        if (auth_debug_mode)
            printf ("Kerberos V5: error getting forwarded creds: %s\r\n",
                    krb5_get_err_text (context, ret));
        return;
    }

    if(!Data(ap, KRB_FORWARD, out_data.data, out_data.length)) {
        if (auth_debug_mode)
            printf("Not enough room for authentication data\r\n");
    } else {
        if (auth_debug_mode)
            printf("Forwarded local Kerberos V5 credentials to server\r\n");
    }
}

#if defined(DCE)
/* if this was a K5 authentication try and join a PAG for the user. */
void
kerberos5_dfspag(void)
{
    if (dfsk5ok) {
        dfspag = krb5_dfs_pag(context, dfsfwd, ticket->client,
                              UserNameRequested);
    }
}
#endif

int
kerberos5_set_forward(int on)
{
    if(on == 0)
        forward_flags &= ~OPTS_FORWARD_CREDS;
    if(on == 1)
        forward_flags |= OPTS_FORWARD_CREDS;
    if(on == -1)
        forward_flags ^= OPTS_FORWARD_CREDS;
    return 0;
}

int
kerberos5_set_forwardable(int on)
{
    if(on == 0)
        forward_flags &= ~OPTS_FORWARDABLE_CREDS;
    if(on == 1)
        forward_flags |= OPTS_FORWARDABLE_CREDS;
    if(on == -1)
        forward_flags ^= OPTS_FORWARDABLE_CREDS;
    return 0;
}

#endif /* KRB5 */