/*
 * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * 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. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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.
 */

#include "gsskrb5_locl.h"

/*
 * copy the addresses from `input_chan_bindings' (if any) to
 * the auth context `ac'
 */

static OM_uint32
set_addresses (krb5_context context,
               krb5_auth_context ac,
               const gss_channel_bindings_t input_chan_bindings)
{
    /* Port numbers are expected to be in application_data.value,
     * initator's port first */

    krb5_address initiator_addr, acceptor_addr;
    krb5_error_code kret;

    if (input_chan_bindings == GSS_C_NO_CHANNEL_BINDINGS
        || input_chan_bindings->application_data.length !=
        2 * sizeof(ac->local_port))
        return 0;

    memset(&initiator_addr, 0, sizeof(initiator_addr));
    memset(&acceptor_addr, 0, sizeof(acceptor_addr));

    ac->local_port =
        *(int16_t *) input_chan_bindings->application_data.value;

    ac->remote_port =
        *((int16_t *) input_chan_bindings->application_data.value + 1);

    kret = _gsskrb5i_address_to_krb5addr(context,
                                         input_chan_bindings->acceptor_addrtype,
                                         &input_chan_bindings->acceptor_address,
                                         ac->remote_port,
                                         &acceptor_addr);
    if (kret)
        return kret;

    kret = _gsskrb5i_address_to_krb5addr(context,
                                         input_chan_bindings->initiator_addrtype,
                                         &input_chan_bindings->initiator_address,
                                         ac->local_port,
                                         &initiator_addr);
    if (kret) {
        krb5_free_address (context, &acceptor_addr);
        return kret;
    }

    kret = krb5_auth_con_setaddrs(context,
                                  ac,
                                  &initiator_addr,  /* local address */
                                  &acceptor_addr);  /* remote address */

    krb5_free_address (context, &initiator_addr);
    krb5_free_address (context, &acceptor_addr);

#if 0
    free(input_chan_bindings->application_data.value);
    input_chan_bindings->application_data.value = NULL;
    input_chan_bindings->application_data.length = 0;
#endif

    return kret;
}

OM_uint32
_gsskrb5_create_ctx(
        OM_uint32 * minor_status,
        gss_ctx_id_t * context_handle,
        krb5_context context,
        const gss_channel_bindings_t input_chan_bindings,
        enum gss_ctx_id_t_state state)
{
    krb5_error_code kret;
    gsskrb5_ctx ctx;

    *context_handle = NULL;

    ctx = malloc(sizeof(*ctx));
    if (ctx == NULL) {
        *minor_status = ENOMEM;
        return GSS_S_FAILURE;
    }
    ctx->auth_context           = NULL;
    ctx->deleg_auth_context     = NULL;
    ctx->source                 = NULL;
    ctx->target                 = NULL;
    ctx->kcred                  = NULL;
    ctx->ccache                 = NULL;
    ctx->state                  = state;
    ctx->flags                  = 0;
    ctx->more_flags             = 0;
    ctx->service_keyblock       = NULL;
    ctx->ticket                 = NULL;
    krb5_data_zero(&ctx->fwd_data);
    ctx->lifetime               = GSS_C_INDEFINITE;
    ctx->order                  = NULL;
    ctx->crypto                 = NULL;
    HEIMDAL_MUTEX_init(&ctx->ctx_id_mutex);

    kret = krb5_auth_con_init (context, &ctx->auth_context);
    if (kret) {
        *minor_status = kret;
        HEIMDAL_MUTEX_destroy(&ctx->ctx_id_mutex);
        return GSS_S_FAILURE;
    }

    kret = krb5_auth_con_init (context, &ctx->deleg_auth_context);
    if (kret) {
        *minor_status = kret;
        krb5_auth_con_free(context, ctx->auth_context);
        HEIMDAL_MUTEX_destroy(&ctx->ctx_id_mutex);
        return GSS_S_FAILURE;
    }

    kret = set_addresses(context, ctx->auth_context, input_chan_bindings);
    if (kret) {
        *minor_status = kret;

        krb5_auth_con_free(context, ctx->auth_context);
        krb5_auth_con_free(context, ctx->deleg_auth_context);

        HEIMDAL_MUTEX_destroy(&ctx->ctx_id_mutex);

        return GSS_S_BAD_BINDINGS;
    }

    kret = set_addresses(context, ctx->deleg_auth_context, input_chan_bindings);
    if (kret) {
        *minor_status = kret;

        krb5_auth_con_free(context, ctx->auth_context);
        krb5_auth_con_free(context, ctx->deleg_auth_context);

        HEIMDAL_MUTEX_destroy(&ctx->ctx_id_mutex);

        return GSS_S_BAD_BINDINGS;
    }

    /*
     * We need a sequence number
     */

    krb5_auth_con_addflags(context,
                           ctx->auth_context,
                           KRB5_AUTH_CONTEXT_DO_SEQUENCE |
                           KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED,
                           NULL);

    /*
     * We need a sequence number
     */

    krb5_auth_con_addflags(context,
                           ctx->deleg_auth_context,
                           KRB5_AUTH_CONTEXT_DO_SEQUENCE |
                           KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED,
                           NULL);

    *context_handle = (gss_ctx_id_t)ctx;

    return GSS_S_COMPLETE;
}


static OM_uint32
gsskrb5_get_creds(
        OM_uint32 * minor_status,
        krb5_context context,
        krb5_ccache ccache,
        gsskrb5_ctx ctx,
        const gss_name_t target_name,
        int use_dns,
        OM_uint32 time_req,
        OM_uint32 * time_rec)
{
    OM_uint32 ret;
    krb5_error_code kret;
    krb5_creds this_cred;
    OM_uint32 lifetime_rec;

    if (ctx->target) {
        krb5_free_principal(context, ctx->target);
        ctx->target = NULL;
    }
    if (ctx->kcred) {
        krb5_free_creds(context, ctx->kcred);
        ctx->kcred = NULL;
    }

    ret = _gsskrb5_canon_name(minor_status, context, use_dns,
                              ctx->source, target_name, &ctx->target);
    if (ret)
        return ret;

    memset(&this_cred, 0, sizeof(this_cred));
    this_cred.client = ctx->source;
    this_cred.server = ctx->target;

    if (time_req && time_req != GSS_C_INDEFINITE) {
        krb5_timestamp ts;

        krb5_timeofday (context, &ts);
        this_cred.times.endtime = ts + time_req;
    } else {
        this_cred.times.endtime   = 0;
    }

    this_cred.session.keytype = KEYTYPE_NULL;

    kret = krb5_get_credentials(context,
                                0,
                                ccache,
                                &this_cred,
                                &ctx->kcred);
    if (kret) {
        *minor_status = kret;
        return GSS_S_FAILURE;
    }

    ctx->lifetime = ctx->kcred->times.endtime;

    ret = _gsskrb5_lifetime_left(minor_status, context,
                                 ctx->lifetime, &lifetime_rec);
    if (ret) return ret;

    if (lifetime_rec == 0) {
        *minor_status = 0;
        return GSS_S_CONTEXT_EXPIRED;
    }

    if (time_rec) *time_rec = lifetime_rec;

    return GSS_S_COMPLETE;
}

static OM_uint32
gsskrb5_initiator_ready(
        OM_uint32 * minor_status,
        gsskrb5_ctx ctx,
        krb5_context context)
{
    OM_uint32 ret;
    int32_t seq_number;
    int is_cfx = 0;
    OM_uint32 flags = ctx->flags;

    krb5_free_creds(context, ctx->kcred);
    ctx->kcred = NULL;

    if (ctx->more_flags & CLOSE_CCACHE)
        krb5_cc_close(context, ctx->ccache);
    ctx->ccache = NULL;

    krb5_auth_con_getremoteseqnumber (context, ctx->auth_context, &seq_number);

    _gsskrb5i_is_cfx(context, ctx, 0);
    is_cfx = (ctx->more_flags & IS_CFX);

    ret = _gssapi_msg_order_create(minor_status,
                                   &ctx->order,
                                   _gssapi_msg_order_f(flags),
                                   seq_number, 0, is_cfx);
    if (ret) return ret;

    ctx->state  = INITIATOR_READY;
    ctx->more_flags     |= OPEN;

    return GSS_S_COMPLETE;
}

/*
 * handle delegated creds in init-sec-context
 */

static void
do_delegation (krb5_context context,
               krb5_auth_context ac,
               krb5_ccache ccache,
               krb5_creds *cred,
               krb5_const_principal name,
               krb5_data *fwd_data,
               uint32_t flagmask,
               uint32_t *flags)
{
    krb5_creds creds;
    KDCOptions fwd_flags;
    krb5_error_code kret;

    memset (&creds, 0, sizeof(creds));
    krb5_data_zero (fwd_data);

    kret = krb5_cc_get_principal(context, ccache, &creds.client);
    if (kret)
        goto out;

    kret = krb5_make_principal(context,
                               &creds.server,
                               creds.client->realm,
                               KRB5_TGS_NAME,
                               creds.client->realm,
                               NULL);
    if (kret)
        goto out;

    creds.times.endtime = 0;

    memset(&fwd_flags, 0, sizeof(fwd_flags));
    fwd_flags.forwarded = 1;
    fwd_flags.forwardable = 1;

    if ( /*target_name->name.name_type != KRB5_NT_SRV_HST ||*/
        name->name.name_string.len < 2)
        goto out;

    kret = krb5_get_forwarded_creds(context,
                                    ac,
                                    ccache,
                                    KDCOptions2int(fwd_flags),
                                    name->name.name_string.val[1],
                                    &creds,
                                    fwd_data);

 out:
    if (kret)
        *flags &= ~flagmask;
    else
        *flags |= flagmask;

    if (creds.client)
        krb5_free_principal(context, creds.client);
    if (creds.server)
        krb5_free_principal(context, creds.server);
}

/*
 * first stage of init-sec-context
 */

static OM_uint32
init_auth
(OM_uint32 * minor_status,
 gsskrb5_cred cred,
 gsskrb5_ctx ctx,
 krb5_context context,
 gss_name_t name,
 const gss_OID mech_type,
 OM_uint32 req_flags,
 OM_uint32 time_req,
 const gss_buffer_t input_token,
 gss_OID * actual_mech_type,
 gss_buffer_t output_token,
 OM_uint32 * ret_flags,
 OM_uint32 * time_rec
    )
{
    OM_uint32 ret = GSS_S_FAILURE;
    krb5_error_code kret;
    krb5_data outbuf;
    krb5_data fwd_data;
    OM_uint32 lifetime_rec;
    int allow_dns = 1;

    krb5_data_zero(&outbuf);
    krb5_data_zero(&fwd_data);

    *minor_status = 0;

    if (actual_mech_type)
        *actual_mech_type = GSS_KRB5_MECHANISM;

    if (cred == NULL) {
        kret = krb5_cc_default (context, &ctx->ccache);
        if (kret) {
            *minor_status = kret;
            ret = GSS_S_FAILURE;
            goto failure;
        }
        ctx->more_flags |= CLOSE_CCACHE;
    } else
        ctx->ccache = cred->ccache;

    kret = krb5_cc_get_principal (context, ctx->ccache, &ctx->source);
    if (kret) {
        *minor_status = kret;
        ret = GSS_S_FAILURE;
        goto failure;
    }

    /*
     * This is hideous glue for (NFS) clients that wants to limit the
     * available enctypes to what it can support (encryption in
     * kernel). If there is no enctypes selected for this credential,
     * reset it to the default set of enctypes.
     */
    {
        krb5_enctype *enctypes = NULL;

        if (cred && cred->enctypes)
            enctypes = cred->enctypes;
        krb5_set_default_in_tkt_etypes(context, enctypes);
    }

    /* canon name if needed for client + target realm */
    kret = krb5_cc_get_config(context, ctx->ccache, NULL,
                              "realm-config", &outbuf);
    if (kret == 0) {
        /* XXX 2 is no server canon */
        if (outbuf.length < 1 || ((((unsigned char *)outbuf.data)[0]) & 2))
            allow_dns = 0;
        krb5_data_free(&outbuf);
    }

    /*
     * First we try w/o dns, hope that the KDC have register alias
     * (and referrals if cross realm) for this principal. If that
     * fails and if we are allowed to using this realm try again with
     * DNS canonicalizion.
     */
    ret = gsskrb5_get_creds(minor_status, context, ctx->ccache,
                            ctx, name, 0, time_req,
                            time_rec);
    if (ret && allow_dns)
        ret = gsskrb5_get_creds(minor_status, context, ctx->ccache,
                                ctx, name, 1, time_req,
                                time_rec);
    if (ret)
        goto failure;

    ctx->lifetime = ctx->kcred->times.endtime;

    ret = _gss_DES3_get_mic_compat(minor_status, ctx, context);
    if (ret)
        goto failure;

    ret = _gsskrb5_lifetime_left(minor_status,
                                 context,
                                 ctx->lifetime,
                                 &lifetime_rec);
    if (ret)
        goto failure;

    if (lifetime_rec == 0) {
        *minor_status = 0;
        ret = GSS_S_CONTEXT_EXPIRED;
        goto failure;
    }

    krb5_auth_con_setkey(context,
                         ctx->auth_context,
                         &ctx->kcred->session);

    kret = krb5_auth_con_generatelocalsubkey(context,
                                             ctx->auth_context,
                                             &ctx->kcred->session);
    if(kret) {
        *minor_status = kret;
        ret = GSS_S_FAILURE;
        goto failure;
    }

    return GSS_S_COMPLETE;

failure:
    if (ctx->ccache && (ctx->more_flags & CLOSE_CCACHE))
        krb5_cc_close(context, ctx->ccache);
    ctx->ccache = NULL;

    return ret;

}

static OM_uint32
init_auth_restart
(OM_uint32 * minor_status,
 gsskrb5_cred cred,
 gsskrb5_ctx ctx,
 krb5_context context,
 OM_uint32 req_flags,
 const gss_channel_bindings_t input_chan_bindings,
 const gss_buffer_t input_token,
 gss_OID * actual_mech_type,
 gss_buffer_t output_token,
 OM_uint32 * ret_flags,
 OM_uint32 * time_rec
    )
{
    OM_uint32 ret = GSS_S_FAILURE;
    krb5_error_code kret;
    krb5_flags ap_options;
    krb5_data outbuf;
    uint32_t flags;
    krb5_data authenticator;
    Checksum cksum;
    krb5_enctype enctype;
    krb5_data fwd_data, timedata;
    int32_t offset = 0, oldoffset = 0;
    uint32_t flagmask;

    krb5_data_zero(&outbuf);
    krb5_data_zero(&fwd_data);

    *minor_status = 0;

    /*
     * If the credential doesn't have ok-as-delegate, check if there
     * is a realm setting and use that.
     */
    if (!ctx->kcred->flags.b.ok_as_delegate) {
        krb5_data data;

        ret = krb5_cc_get_config(context, ctx->ccache, NULL,
                                 "realm-config", &data);
        if (ret == 0) {
            /* XXX 1 is use ok-as-delegate */
            if (data.length < 1 || ((((unsigned char *)data.data)[0]) & 1) == 0)
                req_flags &= ~(GSS_C_DELEG_FLAG|GSS_C_DELEG_POLICY_FLAG);
            krb5_data_free(&data);
        }
    }

    flagmask = 0;

    /* if we used GSS_C_DELEG_POLICY_FLAG, trust KDC */
    if ((req_flags & GSS_C_DELEG_POLICY_FLAG)
        && ctx->kcred->flags.b.ok_as_delegate)
        flagmask |= GSS_C_DELEG_FLAG | GSS_C_DELEG_POLICY_FLAG;
    /* if there still is a GSS_C_DELEG_FLAG, use that */
    if (req_flags & GSS_C_DELEG_FLAG)
        flagmask |= GSS_C_DELEG_FLAG;


    flags = 0;
    ap_options = 0;
    if (flagmask & GSS_C_DELEG_FLAG) {
        do_delegation (context,
                       ctx->deleg_auth_context,
                       ctx->ccache, ctx->kcred, ctx->target,
                       &fwd_data, flagmask, &flags);
    }

    if (req_flags & GSS_C_MUTUAL_FLAG) {
        flags |= GSS_C_MUTUAL_FLAG;
        ap_options |= AP_OPTS_MUTUAL_REQUIRED;
    }

    if (req_flags & GSS_C_REPLAY_FLAG)
        flags |= GSS_C_REPLAY_FLAG;
    if (req_flags & GSS_C_SEQUENCE_FLAG)
        flags |= GSS_C_SEQUENCE_FLAG;
#if 0
    if (req_flags & GSS_C_ANON_FLAG)
        ;                               /* XXX */
#endif
    if (req_flags & GSS_C_DCE_STYLE) {
        /* GSS_C_DCE_STYLE implies GSS_C_MUTUAL_FLAG */
        flags |= GSS_C_DCE_STYLE | GSS_C_MUTUAL_FLAG;
        ap_options |= AP_OPTS_MUTUAL_REQUIRED;
    }
    if (req_flags & GSS_C_IDENTIFY_FLAG)
        flags |= GSS_C_IDENTIFY_FLAG;
    if (req_flags & GSS_C_EXTENDED_ERROR_FLAG)
        flags |= GSS_C_EXTENDED_ERROR_FLAG;

    if (req_flags & GSS_C_CONF_FLAG) {
        flags |= GSS_C_CONF_FLAG;
    }
    if (req_flags & GSS_C_INTEG_FLAG) {
        flags |= GSS_C_INTEG_FLAG;
    }
    if (cred == NULL || !(cred->cred_flags & GSS_CF_NO_CI_FLAGS)) {
        flags |= GSS_C_CONF_FLAG;
        flags |= GSS_C_INTEG_FLAG;
    }
    flags |= GSS_C_TRANS_FLAG;

    if (ret_flags)
        *ret_flags = flags;
    ctx->flags = flags;
    ctx->more_flags |= LOCAL;

    ret = _gsskrb5_create_8003_checksum (minor_status,
                                         input_chan_bindings,
                                         flags,
                                         &fwd_data,
                                         &cksum);
    krb5_data_free (&fwd_data);
    if (ret)
        goto failure;

    enctype = ctx->auth_context->keyblock->keytype;

    ret = krb5_cc_get_config(context, ctx->ccache, ctx->target,
                             "time-offset", &timedata);
    if (ret == 0) {
        if (timedata.length == 4) {
            const u_char *p = timedata.data;
            offset = (p[0] <<24) | (p[1] << 16) | (p[2] << 8) | (p[3] << 0);
        }
        krb5_data_free(&timedata);
    }

    if (offset) {
        krb5_get_kdc_sec_offset (context, &oldoffset, NULL);
        krb5_set_kdc_sec_offset (context, offset, -1);
    }

    kret = _krb5_build_authenticator(context,
                                     ctx->auth_context,
                                     enctype,
                                     ctx->kcred,
                                     &cksum,
                                     &authenticator,
                                     KRB5_KU_AP_REQ_AUTH);

    if (kret) {
        if (offset)
            krb5_set_kdc_sec_offset (context, oldoffset, -1);
        *minor_status = kret;
        ret = GSS_S_FAILURE;
        goto failure;
    }

    kret = krb5_build_ap_req (context,
                              enctype,
                              ctx->kcred,
                              ap_options,
                              authenticator,
                              &outbuf);
    if (offset)
        krb5_set_kdc_sec_offset (context, oldoffset, -1);
    if (kret) {
        *minor_status = kret;
        ret = GSS_S_FAILURE;
        goto failure;
    }

    if (flags & GSS_C_DCE_STYLE) {
        output_token->value = outbuf.data;
        output_token->length = outbuf.length;
    } else {
        ret = _gsskrb5_encapsulate (minor_status, &outbuf, output_token,
                                    (u_char *)(intptr_t)"\x01\x00",
                                    GSS_KRB5_MECHANISM);
        krb5_data_free (&outbuf);
        if (ret)
            goto failure;
    }

    free_Checksum(&cksum);

    if (flags & GSS_C_MUTUAL_FLAG) {
        ctx->state = INITIATOR_WAIT_FOR_MUTAL;
        return GSS_S_CONTINUE_NEEDED;
    }

    return gsskrb5_initiator_ready(minor_status, ctx, context);
failure:
    if (ctx->ccache && (ctx->more_flags & CLOSE_CCACHE))
        krb5_cc_close(context, ctx->ccache);
    ctx->ccache = NULL;

    return ret;
}

static krb5_error_code
handle_error_packet(krb5_context context,
                    gsskrb5_ctx ctx,
                    krb5_data indata)
{
    krb5_error_code kret;
    KRB_ERROR error;

    kret = krb5_rd_error(context, &indata, &error);
    if (kret == 0) {
        kret = krb5_error_from_rd_error(context, &error, NULL);

        /* save the time skrew for this host */
        if (kret == KRB5KRB_AP_ERR_SKEW) {
            krb5_data timedata;
            unsigned char p[4];
            int32_t t = error.stime - time(NULL);

            p[0] = (t >> 24) & 0xFF;
            p[1] = (t >> 16) & 0xFF;
            p[2] = (t >> 8)  & 0xFF;
            p[3] = (t >> 0)  & 0xFF;

            timedata.data = p;
            timedata.length = sizeof(p);

            krb5_cc_set_config(context, ctx->ccache, ctx->target,
                               "time-offset", &timedata);

            if ((ctx->more_flags & RETRIED) == 0)
                 ctx->state = INITIATOR_RESTART;
            ctx->more_flags |= RETRIED;
        }
        free_KRB_ERROR (&error);
    }
    return kret;
}


static OM_uint32
repl_mutual
(OM_uint32 * minor_status,
 gsskrb5_ctx ctx,
 krb5_context context,
 const gss_OID mech_type,
 OM_uint32 req_flags,
 OM_uint32 time_req,
 const gss_channel_bindings_t input_chan_bindings,
 const gss_buffer_t input_token,
 gss_OID * actual_mech_type,
 gss_buffer_t output_token,
 OM_uint32 * ret_flags,
 OM_uint32 * time_rec
    )
{
    OM_uint32 ret;
    krb5_error_code kret;
    krb5_data indata;
    krb5_ap_rep_enc_part *repl;

    output_token->length = 0;
    output_token->value = NULL;

    if (actual_mech_type)
        *actual_mech_type = GSS_KRB5_MECHANISM;

    if (IS_DCE_STYLE(ctx)) {
        /* There is no OID wrapping. */
        indata.length   = input_token->length;
        indata.data     = input_token->value;
        kret = krb5_rd_rep(context,
                           ctx->auth_context,
                           &indata,
                           &repl);
        if (kret) {
            ret = _gsskrb5_decapsulate(minor_status,
                                       input_token,
                                       &indata,
                                       "\x03\x00",
                                       GSS_KRB5_MECHANISM);
            if (ret == GSS_S_COMPLETE) {
                *minor_status = handle_error_packet(context, ctx, indata);
            } else {
                *minor_status = kret;
            }
            return GSS_S_FAILURE;
        }
    } else {
        ret = _gsskrb5_decapsulate (minor_status,
                                    input_token,
                                    &indata,
                                    "\x02\x00",
                                    GSS_KRB5_MECHANISM);
        if (ret == GSS_S_DEFECTIVE_TOKEN) {
            /* check if there is an error token sent instead */
            ret = _gsskrb5_decapsulate (minor_status,
                                        input_token,
                                        &indata,
                                        "\x03\x00",
                                        GSS_KRB5_MECHANISM);
            if (ret == GSS_S_COMPLETE) {
                *minor_status = handle_error_packet(context, ctx, indata);
                return GSS_S_FAILURE;
            }
        }
        kret = krb5_rd_rep (context,
                            ctx->auth_context,
                            &indata,
                            &repl);
        if (kret) {
            *minor_status = kret;
            return GSS_S_FAILURE;
        }
    }

    krb5_free_ap_rep_enc_part (context,
                               repl);

    *minor_status = 0;
    if (time_rec) {
        ret = _gsskrb5_lifetime_left(minor_status,
                                     context,
                                     ctx->lifetime,
                                     time_rec);
    } else {
        ret = GSS_S_COMPLETE;
    }
    if (ret_flags)
        *ret_flags = ctx->flags;

    if (req_flags & GSS_C_DCE_STYLE) {
        int32_t local_seq, remote_seq;
        krb5_data outbuf;

        /*
         * So DCE_STYLE is strange. The client echos the seq number
         * that the server used in the server's mk_rep in its own
         * mk_rep(). After when done, it resets to it's own seq number
         * for the gss_wrap calls.
         */

        krb5_auth_con_getremoteseqnumber(context, ctx->auth_context, &remote_seq);
        krb5_auth_con_getlocalseqnumber(context, ctx->auth_context, &local_seq);
        krb5_auth_con_setlocalseqnumber(context, ctx->auth_context, remote_seq);

        kret = krb5_mk_rep(context, ctx->auth_context, &outbuf);
        if (kret) {
            *minor_status = kret;
            return GSS_S_FAILURE;
        }

        /* reset local seq number */
        krb5_auth_con_setlocalseqnumber(context, ctx->auth_context, local_seq);

        output_token->length = outbuf.length;
        output_token->value  = outbuf.data;
    }

    return gsskrb5_initiator_ready(minor_status, ctx, context);
}

/*
 * gss_init_sec_context
 */

OM_uint32 GSSAPI_CALLCONV _gsskrb5_init_sec_context
(OM_uint32 * minor_status,
 const gss_cred_id_t cred_handle,
 gss_ctx_id_t * context_handle,
 const gss_name_t target_name,
 const gss_OID mech_type,
 OM_uint32 req_flags,
 OM_uint32 time_req,
 const gss_channel_bindings_t input_chan_bindings,
 const gss_buffer_t input_token,
 gss_OID * actual_mech_type,
 gss_buffer_t output_token,
 OM_uint32 * ret_flags,
 OM_uint32 * time_rec
    )
{
    krb5_context context;
    gsskrb5_cred cred = (gsskrb5_cred)cred_handle;
    gsskrb5_ctx ctx;
    OM_uint32 ret;

    GSSAPI_KRB5_INIT (&context);

    output_token->length = 0;
    output_token->value  = NULL;

    if (context_handle == NULL) {
        *minor_status = 0;
        return GSS_S_FAILURE | GSS_S_CALL_BAD_STRUCTURE;
    }

    if (ret_flags)
        *ret_flags = 0;
    if (time_rec)
        *time_rec = 0;

    if (target_name == GSS_C_NO_NAME) {
        if (actual_mech_type)
            *actual_mech_type = GSS_C_NO_OID;
        *minor_status = 0;
        return GSS_S_BAD_NAME;
    }

    if (mech_type != GSS_C_NO_OID &&
        !gss_oid_equal(mech_type, GSS_KRB5_MECHANISM))
        return GSS_S_BAD_MECH;

    if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
        OM_uint32 ret1;

        if (*context_handle != GSS_C_NO_CONTEXT) {
            *minor_status = 0;
            return GSS_S_FAILURE | GSS_S_CALL_BAD_STRUCTURE;
        }

        ret1 = _gsskrb5_create_ctx(minor_status,
                                  context_handle,
                                  context,
                                  input_chan_bindings,
                                  INITIATOR_START);
        if (ret1)
            return ret1;
    }

    if (*context_handle == GSS_C_NO_CONTEXT) {
        *minor_status = 0;
        return GSS_S_FAILURE | GSS_S_CALL_BAD_STRUCTURE;
    }

    ctx = (gsskrb5_ctx) *context_handle;

    HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);

 again:
    switch (ctx->state) {
    case INITIATOR_START:
        ret = init_auth(minor_status,
                        cred,
                        ctx,
                        context,
                        target_name,
                        mech_type,
                        req_flags,
                        time_req,
                        input_token,
                        actual_mech_type,
                        output_token,
                        ret_flags,
                        time_rec);
        if (ret != GSS_S_COMPLETE)
            break;
        /* FALL THOUGH */
    case INITIATOR_RESTART:
        ret = init_auth_restart(minor_status,
                                cred,
                                ctx,
                                context,
                                req_flags,
                                input_chan_bindings,
                                input_token,
                                actual_mech_type,
                                output_token,
                                ret_flags,
                                time_rec);
        break;
    case INITIATOR_WAIT_FOR_MUTAL:
        ret = repl_mutual(minor_status,
                          ctx,
                          context,
                          mech_type,
                          req_flags,
                          time_req,
                          input_chan_bindings,
                          input_token,
                          actual_mech_type,
                          output_token,
                          ret_flags,
                          time_rec);
        if (ctx->state == INITIATOR_RESTART)
            goto again;
        break;
    case INITIATOR_READY:
        /*
         * If we get there, the caller have called
         * gss_init_sec_context() one time too many.
         */
        _gsskrb5_set_status(EINVAL, "init_sec_context "
                            "called one time too many");
        *minor_status = EINVAL;
        ret = GSS_S_BAD_STATUS;
        break;
    default:
        _gsskrb5_set_status(EINVAL, "init_sec_context "
                            "invalid state %d for client",
                            (int)ctx->state);
        *minor_status = EINVAL;
        ret = GSS_S_BAD_STATUS;
        break;
    }
    HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);

    /* destroy context in case of error */
    if (GSS_ERROR(ret)) {
        OM_uint32 min2;
        _gsskrb5_delete_sec_context(&min2, context_handle, GSS_C_NO_BUFFER);
    }

    return ret;

}