/* crypto/buffer/buffer.c */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 *

 * This library is free for commercial and non-commercial use as long as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 *

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 *

 * 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 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. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 *

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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.

 *

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */

#include <stdio.h>

#include "cryptlib.h"

#include <openssl/buffer.h>

/*

 * LIMIT_BEFORE_EXPANSION is the maximum n such that (n+3)/3*4 < 2**31. That

 * function is applied in several functions in this file and this limit

 * ensures that the result fits in an int.

 */

#define LIMIT_BEFORE_EXPANSION 0x5ffffffc

BUF_MEM *BUF_MEM_new(void)

{

    BUF_MEM *ret;

    ret = OPENSSL_malloc(sizeof(BUF_MEM));

    if (ret == NULL) {

        BUFerr(BUF_F_BUF_MEM_NEW, ERR_R_MALLOC_FAILURE);

        return (NULL);

    }

    ret->length = 0;

    ret->max = 0;

    ret->data = NULL;

    return (ret);

}

void BUF_MEM_free(BUF_MEM *a)

{

    if (a == NULL)

        return;

    if (a->data != NULL) {

        OPENSSL_cleanse(a->data, a->max);

        OPENSSL_free(a->data);

    }

    OPENSSL_free(a);

}

int BUF_MEM_grow(BUF_MEM *str, size_t len)

{

    char *ret;

    size_t n;

    if (str->length >= len) {

        str->length = len;

        return (len);

    }

    if (str->max >= len) {

        memset(&str->data[str->length], 0, len - str->length);

        str->length = len;

        return (len);

    }

    /* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */

    if (len > LIMIT_BEFORE_EXPANSION) {

        BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    n = (len + 3) / 3 * 4;

    if (str->data == NULL)

        ret = OPENSSL_malloc(n);

    else

        ret = OPENSSL_realloc(str->data, n);

    if (ret == NULL) {

        BUFerr(BUF_F_BUF_MEM_GROW, ERR_R_MALLOC_FAILURE);

        len = 0;

    } else {

        str->data = ret;

        str->max = n;

        memset(&str->data[str->length], 0, len - str->length);

        str->length = len;

    }

    return (len);

}

int BUF_MEM_grow_clean(BUF_MEM *str, size_t len)

{

    char *ret;

    size_t n;

    if (str->length >= len) {

        memset(&str->data[len], 0, str->length - len);

        str->length = len;

        return (len);

    }

    if (str->max >= len) {

        memset(&str->data[str->length], 0, len - str->length);

        str->length = len;

        return (len);

    }

    /* This limit is sufficient to ensure (len+3)/3*4 < 2**31 */

    if (len > LIMIT_BEFORE_EXPANSION) {

        BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    n = (len + 3) / 3 * 4;

    if (str->data == NULL)

        ret = OPENSSL_malloc(n);

    else

        ret = OPENSSL_realloc_clean(str->data, str->max, n);

    if (ret == NULL) {

        BUFerr(BUF_F_BUF_MEM_GROW_CLEAN, ERR_R_MALLOC_FAILURE);

        len = 0;

    } else {

        str->data = ret;

        str->max = n;

        memset(&str->data[str->length], 0, len - str->length);

        str->length = len;

    }

    return (len);

}

void BUF_reverse(unsigned char *out, const unsigned char *in, size_t size)

{

    size_t i;

    if (in) {

        out += size - 1;

        for (i = 0; i < size; i++)

            *out-- = *in++;

    } else {

        unsigned char *q;

        char c;

        q = out + size - 1;

        for (i = 0; i < size / 2; i++) {

            c = *q;

            *q-- = *out;

            *out++ = c;

        }

    }

}