/*
 * Copyright (c) 2004, PADL Software Pty Ltd.
 * 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 PADL Software 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 PADL SOFTWARE 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 PADL SOFTWARE 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.
 */

/*
 *  glue routine for _gsskrb5_inquire_sec_context_by_oid
 */

#include "gsskrb5_locl.h"

static OM_uint32
get_bool(OM_uint32 *minor_status,
	 const gss_buffer_t value,
	 int *flag)
{
    if (value->value == NULL || value->length != 1) {
	*minor_status = EINVAL;
	return GSS_S_FAILURE;
    }
    *flag = *((const char *)value->value) != 0;
    return GSS_S_COMPLETE;
}

static OM_uint32
get_string(OM_uint32 *minor_status,
	   const gss_buffer_t value,
	   char **str)
{
    if (value == NULL || value->length == 0) {
	*str = NULL;
    } else {
	*str = malloc(value->length + 1);
	if (*str == NULL) {
	    *minor_status = 0;
	    return GSS_S_UNAVAILABLE;
	}
	memcpy(*str, value->value, value->length);
	(*str)[value->length] = '\0';
    }
    return GSS_S_COMPLETE;
}

static OM_uint32
get_int32(OM_uint32 *minor_status,
	  const gss_buffer_t value,
	  OM_uint32 *ret)
{
    *minor_status = 0;
    if (value == NULL || value->length == 0)
	*ret = 0;
    else if (value->length == sizeof(*ret))
	memcpy(ret, value->value, sizeof(*ret));
    else
	return GSS_S_UNAVAILABLE;

    return GSS_S_COMPLETE;
}

static OM_uint32
set_int32(OM_uint32 *minor_status,
	  const gss_buffer_t value,
	  OM_uint32 set)
{
    *minor_status = 0;
    if (value->length == sizeof(set))
	memcpy(value->value, &set, sizeof(set));
    else
	return GSS_S_UNAVAILABLE;

    return GSS_S_COMPLETE;
}

/*
 * GSS_KRB5_IMPORT_RFC4121_CONTEXT_X is an internal, private interface
 * to allow SAnon to create a skeletal context for using RFC4121 message
 * protection services.
 *
 * rfc4121_args ::= initiator_flag || flags || enctype || session key
 */
static OM_uint32
make_rfc4121_context(OM_uint32 *minor,
		     krb5_context context,
		     gss_ctx_id_t *context_handle,
		     gss_const_buffer_t rfc4121_args)
{
    OM_uint32 major = GSS_S_FAILURE, tmp;
    krb5_error_code ret;
    krb5_storage *sp = NULL;
    gsskrb5_ctx ctx = NULL;
    uint8_t initiator_flag;
    int32_t enctype;
    size_t keysize;
    krb5_keyblock *key;

    *minor = 0;

    sp = krb5_storage_from_readonly_mem(rfc4121_args->value, rfc4121_args->length);
    if (sp == NULL) {
	ret = ENOMEM;
	goto out;
    }

    krb5_storage_set_byteorder(sp, KRB5_STORAGE_BYTEORDER_HOST);

    ctx = calloc(1, sizeof(*ctx));
    if (ctx == NULL) {
	ret = ENOMEM;
	goto out;
    }

    ret = krb5_ret_uint8(sp, &initiator_flag);
    if (ret != 0)
	goto out;

    ret = krb5_ret_uint32(sp, &ctx->flags);
    if (ret != 0)
	goto out;

    ctx->more_flags = IS_CFX | ACCEPTOR_SUBKEY | OPEN;
    if (initiator_flag)
	ctx->more_flags |= LOCAL;

    ctx->state = initiator_flag ? INITIATOR_READY : ACCEPTOR_READY;

    ret = krb5_ret_int32(sp, &enctype);
    if (ret != 0)
	goto out;

    ret = krb5_enctype_keysize(context, enctype, &keysize);
    if (ret != 0)
	goto out;

    ctx->auth_context = calloc(1, sizeof(*ctx->auth_context));
    if (ctx->auth_context == NULL) {
	ret = ENOMEM;
	goto out;
    }

    key = calloc(1, sizeof(*key));
    if (key == NULL) {
	ret = ENOMEM;
	goto out;
    }
    if (initiator_flag)
	ctx->auth_context->remote_subkey = key;
    else
	ctx->auth_context->local_subkey = key;

    key->keytype = enctype;
    key->keyvalue.data = malloc(keysize);
    if (key->keyvalue.data == NULL) {
	ret = ENOMEM;
	goto out;
    }

    if (krb5_storage_read(sp, key->keyvalue.data, keysize) != keysize) {
	ret = EINVAL;
	goto out;
    }
    key->keyvalue.length = keysize;

    ret = krb5_crypto_init(context, key, 0, &ctx->crypto);
    if (ret != 0)
	goto out;

    major = _gssapi_msg_order_create(minor, &ctx->order,
				     _gssapi_msg_order_f(ctx->flags),
				     0, 0, 1);
    if (major != GSS_S_COMPLETE)
	goto out;

out:
    krb5_storage_free(sp);

    if (major != GSS_S_COMPLETE) {
	if (*minor == 0)
	    *minor = ret;
	_gsskrb5_delete_sec_context(&tmp, (gss_ctx_id_t *)&ctx, GSS_C_NO_BUFFER);
    } else {
	*context_handle = (gss_ctx_id_t)ctx;
    }

    return major;
}

OM_uint32 GSSAPI_CALLCONV
_gsskrb5_set_sec_context_option
           (OM_uint32 *minor_status,
            gss_ctx_id_t *context_handle,
            const gss_OID desired_object,
            const gss_buffer_t value)
{
    krb5_context context;
    OM_uint32 maj_stat;

    GSSAPI_KRB5_INIT (&context);

    if (value == GSS_C_NO_BUFFER) {
	*minor_status = EINVAL;
	return GSS_S_FAILURE;
    }

    if (gss_oid_equal(desired_object, GSS_KRB5_COMPAT_DES3_MIC_X)) {
	gsskrb5_ctx ctx;
	int flag;

	if (*context_handle == GSS_C_NO_CONTEXT) {
	    *minor_status = EINVAL;
	    return GSS_S_NO_CONTEXT;
	}

	maj_stat = get_bool(minor_status, value, &flag);
	if (maj_stat != GSS_S_COMPLETE)
	    return maj_stat;

	ctx = (gsskrb5_ctx)*context_handle;
	HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
	if (flag)
	    ctx->more_flags |= COMPAT_OLD_DES3;
	else
	    ctx->more_flags &= ~COMPAT_OLD_DES3;
	ctx->more_flags |= COMPAT_OLD_DES3_SELECTED;
	HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
	return GSS_S_COMPLETE;
    } else if (gss_oid_equal(desired_object, GSS_KRB5_SET_DNS_CANONICALIZE_X)) {
	int flag;

	maj_stat = get_bool(minor_status, value, &flag);
	if (maj_stat != GSS_S_COMPLETE)
	    return maj_stat;

	krb5_set_dns_canonicalize_hostname(context, flag);
	return GSS_S_COMPLETE;

    } else if (gss_oid_equal(desired_object, GSS_KRB5_REGISTER_ACCEPTOR_IDENTITY_X)) {
	char *str;

	maj_stat = get_string(minor_status, value, &str);
	if (maj_stat != GSS_S_COMPLETE)
	    return maj_stat;

	maj_stat = _gsskrb5_register_acceptor_identity(minor_status, str);
	free(str);

	return maj_stat;

    } else if (gss_oid_equal(desired_object, GSS_KRB5_SET_DEFAULT_REALM_X)) {
	char *str;

	maj_stat = get_string(minor_status, value, &str);
	if (maj_stat != GSS_S_COMPLETE)
	    return maj_stat;
	if (str == NULL) {
	    *minor_status = 0;
	    return GSS_S_CALL_INACCESSIBLE_READ;
	}

	krb5_set_default_realm(context, str);
	free(str);

	*minor_status = 0;
	return GSS_S_COMPLETE;

    } else if (gss_oid_equal(desired_object, GSS_KRB5_SEND_TO_KDC_X)) {

	*minor_status = EINVAL;
	return GSS_S_FAILURE;

    } else if (gss_oid_equal(desired_object, GSS_KRB5_SET_TIME_OFFSET_X)) {
	OM_uint32 offset;
	time_t t;

	maj_stat = get_int32(minor_status, value, &offset);
	if (maj_stat != GSS_S_COMPLETE)
	    return maj_stat;

	t = time(NULL) + offset;

	krb5_set_real_time(context, t, 0);

	*minor_status = 0;
	return GSS_S_COMPLETE;
    } else if (gss_oid_equal(desired_object, GSS_KRB5_GET_TIME_OFFSET_X)) {
	krb5_timestamp sec;
	int32_t usec;
	time_t t;

	t = time(NULL);

	krb5_us_timeofday (context, &sec, &usec);

	maj_stat = set_int32(minor_status, value, sec - t);
	if (maj_stat != GSS_S_COMPLETE)
	    return maj_stat;

	*minor_status = 0;
	return GSS_S_COMPLETE;
    } else if (gss_oid_equal(desired_object, GSS_KRB5_PLUGIN_REGISTER_X)) {
	struct gsskrb5_krb5_plugin c;

	if (value->length != sizeof(c)) {
	    *minor_status = EINVAL;
	    return GSS_S_FAILURE;
	}
	memcpy(&c, value->value, sizeof(c));
	krb5_plugin_register(context, c.type, c.name, c.symbol);

	*minor_status = 0;
	return GSS_S_COMPLETE;
    } else if (gss_oid_equal(desired_object, GSS_KRB5_CCACHE_NAME_X)) {
	struct gsskrb5_ccache_name_args *args = value->value;

	if (value->length != sizeof(*args)) {
	    *minor_status = EINVAL;
	    return GSS_S_FAILURE;
	}

	return _gsskrb5_krb5_ccache_name(minor_status, args->name, &args->out_name);
    } else if (gss_oid_equal(desired_object, GSS_KRB5_IMPORT_RFC4121_CONTEXT_X)) {
	return make_rfc4121_context(minor_status, context, context_handle, value);
    }

    *minor_status = EINVAL;
    return GSS_S_FAILURE;
}