/* $OpenBSD: bio_md.c,v 1.18 2022/01/14 08:40:57 tb Exp $ */

/* 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 <errno.h>

#include <openssl/buffer.h>

#include <openssl/evp.h>

#include "bio_local.h"

#include "evp_locl.h"

/* BIO_put and BIO_get both add to the digest,

 * BIO_gets returns the digest */

static int md_write(BIO *h, char const *buf, int num);

static int md_read(BIO *h, char *buf, int size);

/*static int md_puts(BIO *h, const char *str); */

static int md_gets(BIO *h, char *str, int size);

static long md_ctrl(BIO *h, int cmd, long arg1, void *arg2);

static int md_new(BIO *h);

static int md_free(BIO *data);

static long md_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);

static const BIO_METHOD methods_md = {

  .type = BIO_TYPE_MD,

  .name = "message digest",

  .bwrite = md_write,

  .bread = md_read,

  .bgets = md_gets,

  .ctrl = md_ctrl,

  .create = md_new,

  .destroy = md_free,

  .callback_ctrl = md_callback_ctrl

};

const BIO_METHOD *

BIO_f_md(void)

{

  return (&methods_md);

}

static int

md_new(BIO *bi)

{

  EVP_MD_CTX *ctx;

  ctx = EVP_MD_CTX_create();

  if (ctx == NULL)

    return (0);

  bi->init = 0;

  bi->ptr = (char *)ctx;

  bi->flags = 0;

  return (1);

}

static int

md_free(BIO *a)

{

  if (a == NULL)

    return (0);

  EVP_MD_CTX_destroy(a->ptr);

  a->ptr = NULL;

  a->init = 0;

  a->flags = 0;

  return (1);

}

static int

md_read(BIO *b, char *out, int outl)

{

  int ret = 0;

  EVP_MD_CTX *ctx;

  if (out == NULL)

    return (0);

  ctx = b->ptr;

  if ((ctx == NULL) || (b->next_bio == NULL))

    return (0);

  ret = BIO_read(b->next_bio, out, outl);

  if (b->init) {

    if (ret > 0) {

      if (EVP_DigestUpdate(ctx, (unsigned char *)out,

          (unsigned int)ret) <= 0)

        return (-1);

    }

  }

  BIO_clear_retry_flags(b);

  BIO_copy_next_retry(b);

  return (ret);

}

static int

md_write(BIO *b, const char *in, int inl)

{

  int ret = 0;

  EVP_MD_CTX *ctx;

  if ((in == NULL) || (inl <= 0))

    return (0);

  ctx = b->ptr;

  if ((ctx != NULL) && (b->next_bio != NULL))

    ret = BIO_write(b->next_bio, in, inl);

  if (b->init) {

    if (ret > 0) {

      if (!EVP_DigestUpdate(ctx, (const unsigned char *)in,

          (unsigned int)ret)) {

        BIO_clear_retry_flags(b);

        return 0;

      }

    }

  }

  if (b->next_bio != NULL) {

    BIO_clear_retry_flags(b);

    BIO_copy_next_retry(b);

  }

  return (ret);

}

static long

md_ctrl(BIO *b, int cmd, long num, void *ptr)

{

  EVP_MD_CTX *ctx, *dctx, **pctx;

  const EVP_MD **ppmd;

  EVP_MD *md;

  long ret = 1;

  BIO *dbio;

  ctx = b->ptr;

  switch (cmd) {

  case BIO_CTRL_RESET:

    if (b->init)

      ret = EVP_DigestInit_ex(ctx, ctx->digest, NULL);

    else

      ret = 0;

    if (ret > 0)

      ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

    break;

  case BIO_C_GET_MD:

    if (b->init) {

      ppmd = ptr;

      *ppmd = ctx->digest;

    } else

      ret = 0;

    break;

  case BIO_C_GET_MD_CTX:

    pctx = ptr;

    *pctx = ctx;

    b->init = 1;

    break;

  case BIO_C_SET_MD_CTX:

    if (b->init)

      b->ptr = ptr;

    else

      ret = 0;

    break;

  case BIO_C_DO_STATE_MACHINE:

    BIO_clear_retry_flags(b);

    ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

    BIO_copy_next_retry(b);

    break;

  case BIO_C_SET_MD:

    md = ptr;

    ret = EVP_DigestInit_ex(ctx, md, NULL);

    if (ret > 0)

      b->init = 1;

    break;

  case BIO_CTRL_DUP:

    dbio = ptr;

    dctx = dbio->ptr;

    if (!EVP_MD_CTX_copy_ex(dctx, ctx))

      return 0;

    b->init = 1;

    break;

  default:

    ret = BIO_ctrl(b->next_bio, cmd, num, ptr);

    break;

  }

  return (ret);

}

static long

md_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)

{

  long ret = 1;

  if (b->next_bio == NULL)

    return (0);

  switch (cmd) {

  default:

    ret = BIO_callback_ctrl(b->next_bio, cmd, fp);

    break;

  }

  return (ret);

}

static int

md_gets(BIO *bp, char *buf, int size)

{

  EVP_MD_CTX *ctx;

  unsigned int ret;

  ctx = bp->ptr;

  if (size < ctx->digest->md_size)

    return (0);

  if (EVP_DigestFinal_ex(ctx, (unsigned char *)buf, &ret) <= 0)

    return -1;

  return ((int)ret);

}

/*

static int md_puts(bp,str)

BIO *bp;

char *str;

  {

  return(-1);

  }

*/