/*
 * Copyright (c) 1997 - 2007 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 "krb5_locl.h"

/**
 * Reset the (potentially uninitialized) krb5_data structure.
 *
 * @param p krb5_data to reset.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_data_zero(krb5_data *p)
{
    p->length = 0;
    p->data   = NULL;
}

/**
 * Free the content of krb5_data structure, its ok to free a zeroed
 * structure (with memset() or krb5_data_zero()). When done, the
 * structure will be zeroed. The same function is called
 * krb5_free_data_contents() in MIT Kerberos.
 *
 * @param p krb5_data to free.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_data_free(krb5_data *p)
{
    free(p->data);
    krb5_data_zero(p);
}

/**
 * Free krb5_data (and its content).
 *
 * @param context Kerberos 5 context.
 * @param p krb5_data to free.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION void KRB5_LIB_CALL
krb5_free_data(krb5_context context,
	       krb5_data *p)
{
    krb5_data_free(p);
    free(p);
}

/**
 * Allocate data of and krb5_data.
 *
 * @param p krb5_data to allocate.
 * @param len size to allocate.
 *
 * @return Returns 0 to indicate success. Otherwise an kerberos et
 * error code is returned.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_data_alloc(krb5_data *p, int len)
{
    p->data = malloc(len);
    if(len && p->data == NULL)
	return ENOMEM;
    p->length = len;
    return 0;
}

/**
 * Grow (or shrink) the content of krb5_data to a new size.
 *
 * @param p krb5_data to free.
 * @param len new size.
 *
 * @return Returns 0 to indicate success. Otherwise an kerberos et
 * error code is returned.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_data_realloc(krb5_data *p, int len)
{
    void *tmp;
    tmp = realloc(p->data, len);
    if(len && !tmp)
	return ENOMEM;
    p->data = tmp;
    p->length = len;
    return 0;
}

/**
 * Copy the data of len into the krb5_data.
 *
 * @param p krb5_data to copy into.
 * @param data data to copy..
 * @param len new size.
 *
 * @return Returns 0 to indicate success. Otherwise an kerberos et
 * error code is returned.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_data_copy(krb5_data *p, const void *data, size_t len)
{
    if (len) {
	if(krb5_data_alloc(p, len))
	    return ENOMEM;
	memcpy(p->data,	data, len);
    } else
	p->data = NULL;
    p->length = len;
    return 0;
}

/**
 * Copy the data into a newly allocated krb5_data.
 *
 * @param context Kerberos 5 context.
 * @param indata the krb5_data data to copy
 * @param outdata new krb5_date to copy too. Free with krb5_free_data().
 *
 * @return Returns 0 to indicate success. Otherwise an kerberos et
 * error code is returned.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_copy_data(krb5_context context,
	       const krb5_data *indata,
	       krb5_data **outdata)
{
    krb5_error_code ret;
    ALLOC(*outdata, 1);
    if(*outdata == NULL)
	return krb5_enomem(context);
    ret = der_copy_octet_string(indata, *outdata);
    if(ret) {
	krb5_clear_error_message (context);
	free(*outdata);
	*outdata = NULL;
    }
    return ret;
}

/**
 * Compare to data.
 *
 * @param data1 krb5_data to compare
 * @param data2 krb5_data to compare
 *
 * @return return the same way as memcmp(), useful when sorting.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION int KRB5_LIB_CALL
krb5_data_cmp(const krb5_data *data1, const krb5_data *data2)
{
    size_t len = data1->length < data2->length ? data1->length : data2->length;
    int cmp = memcmp(data1->data, data2->data, len);

    if (cmp == 0)
	return data1->length - data2->length;
    return cmp;
}

/**
 * Compare to data not exposing timing information from the checksum data
 *
 * @param data1 krb5_data to compare
 * @param data2 krb5_data to compare
 *
 * @return returns zero for same data, otherwise non zero.
 *
 * @ingroup krb5
 */

KRB5_LIB_FUNCTION int KRB5_LIB_CALL
krb5_data_ct_cmp(const krb5_data *data1, const krb5_data *data2)
{
    if (data1->length != data2->length)
	return data1->length - data2->length;
    return ct_memcmp(data1->data, data2->data, data1->length);
}
