/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2005 Doug Rabson
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <gssapi/gssapi.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "mech_switch.h"
#include "name.h"
#include "cred.h"
#include "context.h"
#include "utils.h"

static gss_cred_id_t
_gss_mech_cred_find(gss_cred_id_t cred_handle, gss_OID mech_type)
{
        struct _gss_cred *cred = (struct _gss_cred *)cred_handle;
        struct _gss_mechanism_cred *mc;

        if (cred == NULL)
                return GSS_C_NO_CREDENTIAL;

        SLIST_FOREACH(mc, &cred->gc_mc, gmc_link) {
                if (gss_oid_equal(mech_type, mc->gmc_mech_oid))
                        return mc->gmc_cred;
        }
        return GSS_C_NO_CREDENTIAL;
}

OM_uint32
gss_init_sec_context(OM_uint32 * minor_status,
    const gss_cred_id_t initiator_cred_handle,
    gss_ctx_id_t * context_handle,
    const gss_name_t target_name,
    const gss_OID input_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 major_status;
        struct _gss_mech_switch *m;
        struct _gss_name *name = (struct _gss_name *) target_name;
        struct _gss_mechanism_name *mn;
        struct _gss_context *ctx = (struct _gss_context *) *context_handle;
        gss_cred_id_t cred_handle;
        int allocated_ctx;
        gss_OID mech_type = input_mech_type;

        *minor_status = 0;

        _gss_buffer_zero(output_token);
        if (actual_mech_type)
                *actual_mech_type = GSS_C_NO_OID;
        if (ret_flags)
                *ret_flags = 0;
        if (time_rec)
                *time_rec = 0;

        /*
         * If we haven't allocated a context yet, do so now and lookup
         * the mechanism switch table. If we have one already, make
         * sure we use the same mechanism switch as before.
         */
        if (!ctx) {
                if (mech_type == GSS_C_NO_OID) {
                        _gss_load_mech();
                        if (_gss_mech_oids == GSS_C_NO_OID_SET
                            || _gss_mech_oids->count == 0)
                                return (GSS_S_BAD_MECH);
                        mech_type = &_gss_mech_oids->elements[0];
                }

                ctx = malloc(sizeof(struct _gss_context));
                if (!ctx) {
                        *minor_status = ENOMEM;
                        return (GSS_S_FAILURE);
                }
                memset(ctx, 0, sizeof(struct _gss_context));
                m = ctx->gc_mech = _gss_find_mech_switch(mech_type);
                if (!m) {
                        free(ctx);
                        return (GSS_S_BAD_MECH);
                }
                allocated_ctx = 1;
        } else {
                m = ctx->gc_mech;
                mech_type = &ctx->gc_mech->gm_mech_oid;
                allocated_ctx = 0;
        }

        /*
         * Find the MN for this mechanism.
         */
        major_status = _gss_find_mn(minor_status, name, mech_type, &mn);
        if (major_status != GSS_S_COMPLETE) {
                if (allocated_ctx)
                        free(ctx);
                return (major_status);
        }

        /*
         * If we have a cred, find the cred for this mechanism.
         */
        cred_handle = _gss_mech_cred_find(initiator_cred_handle, mech_type);

        major_status = m->gm_init_sec_context(minor_status,
            cred_handle,
            &ctx->gc_ctx,
            mn->gmn_name,
            mech_type,
            req_flags,
            time_req,
            input_chan_bindings,
            input_token,
            actual_mech_type,
            output_token,
            ret_flags,
            time_rec);

        if (major_status != GSS_S_COMPLETE
            && major_status != GSS_S_CONTINUE_NEEDED) {
                if (allocated_ctx)
                        free(ctx);
                _gss_buffer_zero(output_token);
                _gss_mg_error(m, major_status, *minor_status);
        } else {
                *context_handle = (gss_ctx_id_t) ctx;
        }

        return (major_status);
}