/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
 * Authors: Doug Rabson <dfr@rabson.org>
 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
 *
 * 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 <sys/param.h>
#include <sys/kernel.h>
#include <sys/kobj.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>

#include <kgssapi/gssapi.h>
#include <kgssapi/gssapi_impl.h>
#include <rpc/rpc.h>

#include "gssd.h"
#include "kgss_if.h"

/*
 * This function should only be called when the gssd
 * daemon running on the system is an old one that
 * does not use gss_krb5_export_lucid_sec_context().
 */
OM_uint32 gss_accept_sec_context(OM_uint32 *minor_status,
    gss_ctx_id_t *context_handle,
    const gss_cred_id_t acceptor_cred_handle,
    const gss_buffer_t input_token,
    const gss_channel_bindings_t input_chan_bindings,
    gss_name_t *src_name,
    gss_OID *mech_type,
    gss_buffer_t output_token,
    OM_uint32 *ret_flags,
    OM_uint32 *time_rec,
    gss_cred_id_t *delegated_cred_handle)
{
        struct accept_sec_context_res res;
        struct accept_sec_context_args args;
        enum clnt_stat stat;
        gss_ctx_id_t ctx = *context_handle;
        gss_name_t name;
        gss_cred_id_t cred;
        CLIENT *cl;

        cl = kgss_gssd_client();
        if (cl == NULL) {
                *minor_status = 0;
                return (GSS_S_FAILURE);
        }

        if (ctx)
                args.ctx = ctx->handle;
        else
                args.ctx = 0;
        if (acceptor_cred_handle)
                args.cred = acceptor_cred_handle->handle;
        else
                args.cred = 0;
        args.input_token = *input_token;
        args.input_chan_bindings = input_chan_bindings;

        bzero(&res, sizeof(res));
        stat = gssd_accept_sec_context_1(&args, &res, cl);
        CLNT_RELEASE(cl);
        if (stat != RPC_SUCCESS) {
                *minor_status = stat;
                return (GSS_S_FAILURE);
        }

        if (res.major_status != GSS_S_COMPLETE
            && res.major_status != GSS_S_CONTINUE_NEEDED) {
                *minor_status = res.minor_status;
                xdr_free((xdrproc_t) xdr_accept_sec_context_res, &res);
                return (res.major_status);
        }

        *minor_status = res.minor_status;

        if (!ctx) {
                ctx = kgss_create_context(res.mech_type);
                if (!ctx) {
                        xdr_free((xdrproc_t) xdr_accept_sec_context_res, &res);
                        *minor_status = 0;
                        return (GSS_S_BAD_MECH);
                }
        }
        *context_handle = ctx;

        ctx->handle = res.ctx;
        name = malloc(sizeof(struct _gss_name_t), M_GSSAPI, M_WAITOK);
        name->handle = res.src_name;
        if (src_name) {
                *src_name = name;
        } else {
                OM_uint32 junk;
                gss_release_name(&junk, &name);
        }
        if (mech_type)
                *mech_type = KGSS_MECH_TYPE(ctx);
        kgss_copy_buffer(&res.output_token, output_token);
        if (ret_flags)
                *ret_flags = res.ret_flags;
        if (time_rec)
                *time_rec = res.time_rec;
        cred = malloc(sizeof(struct _gss_cred_id_t), M_GSSAPI, M_WAITOK);
        cred->handle = res.delegated_cred_handle;
        if (delegated_cred_handle) {
                *delegated_cred_handle = cred;
        } else {
                OM_uint32 junk;
                gss_release_cred(&junk, &cred);
        }

        xdr_free((xdrproc_t) xdr_accept_sec_context_res, &res);

        /*
         * If the context establishment is complete, export it from
         * userland and hand the result (which includes key material
         * etc.) to the kernel implementation.
         */
        if (res.major_status == GSS_S_COMPLETE)
                res.major_status = kgss_transfer_context(ctx, NULL);

        return (res.major_status);
}

/*
 * This function should be called when the gssd daemon is
 * one that uses gss_krb5_export_lucid_sec_context().
 * There is a lot of code common with
 * gss_accept_sec_context().  However, the structures used
 * are not the same and future changes may be needed for
 * this one.  As such, I have not factored out the common
 * code.
 * gss_supports_lucid() may be used to check to see if the
 * gssd daemon uses gss_krb5_export_lucid_sec_context().
 */
OM_uint32 gss_accept_sec_context_lucid_v1(OM_uint32 *minor_status,
    gss_ctx_id_t *context_handle,
    const gss_cred_id_t acceptor_cred_handle,
    const gss_buffer_t input_token,
    const gss_channel_bindings_t input_chan_bindings,
    gss_name_t *src_name,
    gss_OID *mech_type,
    gss_buffer_t output_token,
    OM_uint32 *ret_flags,
    OM_uint32 *time_rec,
    gss_cred_id_t *delegated_cred_handle,
    gss_buffer_t exported_name,
    uid_t *uidp,
    gid_t *gidp,
    int *numgroups,
    gid_t *groups)
{
        struct accept_sec_context_lucid_v1_res res;
        struct accept_sec_context_lucid_v1_args args;
        enum clnt_stat stat;
        gss_ctx_id_t ctx = *context_handle;
        gss_name_t name;
        gss_cred_id_t cred;
        CLIENT *cl;

        cl = kgss_gssd_client();
        if (cl == NULL) {
                *minor_status = 0;
                return (GSS_S_FAILURE);
        }

        if (ctx)
                args.ctx = ctx->handle;
        else
                args.ctx = 0;
        if (acceptor_cred_handle)
                args.cred = acceptor_cred_handle->handle;
        else
                args.cred = 0;
        args.input_token = *input_token;
        args.input_chan_bindings = input_chan_bindings;

        bzero(&res, sizeof(res));
        stat = gssd_accept_sec_context_lucid_v1_1(&args, &res, cl);
        CLNT_RELEASE(cl);
        if (stat != RPC_SUCCESS) {
                *minor_status = stat;
                return (GSS_S_FAILURE);
        }

        if (res.major_status != GSS_S_COMPLETE
            && res.major_status != GSS_S_CONTINUE_NEEDED) {
                *minor_status = res.minor_status;
                xdr_free((xdrproc_t) xdr_accept_sec_context_res, &res);
                return (res.major_status);
        }

        *minor_status = res.minor_status;

        if (!ctx) {
                ctx = kgss_create_context(res.mech_type);
                if (!ctx) {
                        xdr_free((xdrproc_t) xdr_accept_sec_context_res, &res);
                        *minor_status = 0;
                        return (GSS_S_BAD_MECH);
                }
        }
        *context_handle = ctx;

        ctx->handle = res.ctx;
        name = malloc(sizeof(struct _gss_name_t), M_GSSAPI, M_WAITOK);
        name->handle = res.src_name;
        if (src_name) {
                *src_name = name;
        } else {
                OM_uint32 junk;
                gss_release_name(&junk, &name);
        }
        if (mech_type)
                *mech_type = KGSS_MECH_TYPE(ctx);
        kgss_copy_buffer(&res.output_token, output_token);
        if (ret_flags)
                *ret_flags = res.ret_flags;
        if (time_rec)
                *time_rec = res.time_rec;
        cred = malloc(sizeof(struct _gss_cred_id_t), M_GSSAPI, M_WAITOK);
        cred->handle = res.delegated_cred_handle;
        if (delegated_cred_handle) {
                *delegated_cred_handle = cred;
        } else {
                OM_uint32 junk;
                gss_release_cred(&junk, &cred);
        }

        /*
         * If the context establishment is complete, export it from
         * userland and hand the result (which includes key material
         * etc.) to the kernel implementation.
         */
        if (res.major_status == GSS_S_COMPLETE) {
                int i, n;

                /* First, get the unix credentials. */
                *uidp = res.uid;
                *gidp = res.gid;
                n = res.gidlist.gidlist_len;
                if (n > *numgroups)
                        n = *numgroups;
                for (i = 0; i < n; i++)
                        groups[i] = res.gidlist.gidlist_val[i];
                *numgroups = n;

                /* Next, get the exported_name. */
                kgss_copy_buffer(&res.exported_name, exported_name);

                /* Now, handle the lucid credential setup. */
                res.major_status = kgss_transfer_context(ctx, &res.lucid);
                if (res.major_status != GSS_S_COMPLETE)
                        printf("gss_accept_sec_context_lucid_v1: "
                            "transfer failed\n");
        }

        xdr_free((xdrproc_t) xdr_accept_sec_context_res, &res);

        return (res.major_status);
}