/* $OpenBSD: bf_buff.c,v 1.27 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 <errno.h>

#include <stdio.h>

#include <string.h>

#include <openssl/bio.h>

#include <openssl/err.h>

#include "bio_local.h"

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

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

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

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

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

static int buffer_new(BIO *h);

static int buffer_free(BIO *data);

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

#define DEFAULT_BUFFER_SIZE 4096

static const BIO_METHOD methods_buffer = {

  .type = BIO_TYPE_BUFFER,

  .name = "buffer",

  .bwrite = buffer_write,

  .bread = buffer_read,

  .bputs = buffer_puts,

  .bgets = buffer_gets,

  .ctrl = buffer_ctrl,

  .create = buffer_new,

  .destroy = buffer_free,

  .callback_ctrl = buffer_callback_ctrl

};

const BIO_METHOD *

BIO_f_buffer(void)

{

  return (&methods_buffer);

}

static int

buffer_new(BIO *bi)

{

  BIO_F_BUFFER_CTX *ctx;

  ctx = malloc(sizeof(BIO_F_BUFFER_CTX));

  if (ctx == NULL)

    return (0);

  ctx->ibuf = malloc(DEFAULT_BUFFER_SIZE);

  if (ctx->ibuf == NULL) {

    free(ctx);

    return (0);

  }

  ctx->obuf = malloc(DEFAULT_BUFFER_SIZE);

  if (ctx->obuf == NULL) {

    free(ctx->ibuf);

    free(ctx);

    return (0);

  }

  ctx->ibuf_size = DEFAULT_BUFFER_SIZE;

  ctx->obuf_size = DEFAULT_BUFFER_SIZE;

  ctx->ibuf_len = 0;

  ctx->ibuf_off = 0;

  ctx->obuf_len = 0;

  ctx->obuf_off = 0;

  bi->init = 1;

  bi->ptr = (char *)ctx;

  bi->flags = 0;

  return (1);

}

static int

buffer_free(BIO *a)

{

  BIO_F_BUFFER_CTX *b;

  if (a == NULL)

    return (0);

  b = (BIO_F_BUFFER_CTX *)a->ptr;

  free(b->ibuf);

  free(b->obuf);

  free(a->ptr);

  a->ptr = NULL;

  a->init = 0;

  a->flags = 0;

  return (1);

}

static int

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

{

  int i, num = 0;

  BIO_F_BUFFER_CTX *ctx;

  if (out == NULL)

    return (0);

  ctx = (BIO_F_BUFFER_CTX *)b->ptr;

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

    return (0);

  num = 0;

  BIO_clear_retry_flags(b);

start:

  i = ctx->ibuf_len;

  /* If there is stuff left over, grab it */

  if (i != 0) {

    if (i > outl)

      i = outl;

    memcpy(out, &(ctx->ibuf[ctx->ibuf_off]), i);

    ctx->ibuf_off += i;

    ctx->ibuf_len -= i;

    num += i;

    if (outl == i)

      return (num);

    outl -= i;

    out += i;

  }

  /* We may have done a partial read. try to do more.

   * We have nothing in the buffer.

   * If we get an error and have read some data, just return it

   * and let them retry to get the error again.

   * copy direct to parent address space */

  if (outl > ctx->ibuf_size) {

    for (;;) {

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

      if (i <= 0) {

        BIO_copy_next_retry(b);

        if (i < 0)

          return ((num > 0) ? num : i);

        if (i == 0)

          return (num);

      }

      num += i;

      if (outl == i)

        return (num);

      out += i;

      outl -= i;

    }

  }

  /* else */

  /* we are going to be doing some buffering */

  i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);

  if (i <= 0) {

    BIO_copy_next_retry(b);

    if (i < 0)

      return ((num > 0) ? num : i);

    if (i == 0)

      return (num);

  }

  ctx->ibuf_off = 0;

  ctx->ibuf_len = i;

  /* Lets re-read using ourselves :-) */

  goto start;

}

static int

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

{

  int i, num = 0;

  BIO_F_BUFFER_CTX *ctx;

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

    return (0);

  ctx = (BIO_F_BUFFER_CTX *)b->ptr;

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

    return (0);

  BIO_clear_retry_flags(b);

start:

  i = ctx->obuf_size - (ctx->obuf_len + ctx->obuf_off);

  /* add to buffer and return */

  if (i >= inl) {

    memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, inl);

    ctx->obuf_len += inl;

    return (num + inl);

  }

  /* else */

  /* stuff already in buffer, so add to it first, then flush */

  if (ctx->obuf_len != 0) {

    if (i > 0) /* lets fill it up if we can */

    {

      memcpy(&(ctx->obuf[ctx->obuf_off + ctx->obuf_len]), in, i);

      in += i;

      inl -= i;

      num += i;

      ctx->obuf_len += i;

    }

    /* we now have a full buffer needing flushing */

    for (;;) {

      i = BIO_write(b->next_bio, &(ctx->obuf[ctx->obuf_off]),

          ctx->obuf_len);

      if (i <= 0) {

        BIO_copy_next_retry(b);

        if (i < 0)

          return ((num > 0) ? num : i);

        if (i == 0)

          return (num);

      }

      ctx->obuf_off += i;

      ctx->obuf_len -= i;

      if (ctx->obuf_len == 0)

        break;

    }

  }

  /* we only get here if the buffer has been flushed and we

   * still have stuff to write */

  ctx->obuf_off = 0;

  /* we now have inl bytes to write */

  while (inl >= ctx->obuf_size) {

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

    if (i <= 0) {

      BIO_copy_next_retry(b);

      if (i < 0)

        return ((num > 0) ? num : i);

      if (i == 0)

        return (num);

    }

    num += i;

    in += i;

    inl -= i;

    if (inl == 0)

      return (num);

  }

  /* copy the rest into the buffer since we have only a small

   * amount left */

  goto start;

}

static long

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

{

  BIO *dbio;

  BIO_F_BUFFER_CTX *ctx;

  long ret = 1;

  char *p1, *p2;

  int r, i, *ip;

  int ibs, obs;

  ctx = (BIO_F_BUFFER_CTX *)b->ptr;

  switch (cmd) {

  case BIO_CTRL_RESET:

    ctx->ibuf_off = 0;

    ctx->ibuf_len = 0;

    ctx->obuf_off = 0;

    ctx->obuf_len = 0;

    if (b->next_bio == NULL)

      return (0);

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

    break;

  case BIO_CTRL_INFO:

    ret = (long)ctx->obuf_len;

    break;

  case BIO_C_GET_BUFF_NUM_LINES:

    ret = 0;

    p1 = ctx->ibuf;

    for (i = 0; i < ctx->ibuf_len; i++) {

      if (p1[ctx->ibuf_off + i] == '\n')

        ret++;

    }

    break;

  case BIO_CTRL_WPENDING:

    ret = (long)ctx->obuf_len;

    if (ret == 0) {

      if (b->next_bio == NULL)

        return (0);

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

    }

    break;

  case BIO_CTRL_PENDING:

    ret = (long)ctx->ibuf_len;

    if (ret == 0) {

      if (b->next_bio == NULL)

        return (0);

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

    }

    break;

  case BIO_C_SET_BUFF_READ_DATA:

    if (num > ctx->ibuf_size) {

      p1 = malloc(num);

      if (p1 == NULL)

        goto malloc_error;

      free(ctx->ibuf);

      ctx->ibuf = p1;

    }

    ctx->ibuf_off = 0;

    ctx->ibuf_len = (int)num;

    memcpy(ctx->ibuf, ptr, num);

    ret = 1;

    break;

  case BIO_C_SET_BUFF_SIZE:

    if (ptr != NULL) {

      ip = (int *)ptr;

      if (*ip == 0) {

        ibs = (int)num;

        obs = ctx->obuf_size;

      }

      else /* if (*ip == 1) */

      {

        ibs = ctx->ibuf_size;

        obs = (int)num;

      }

    } else {

      ibs = (int)num;

      obs = (int)num;

    }

    p1 = ctx->ibuf;

    p2 = ctx->obuf;

    if ((ibs > DEFAULT_BUFFER_SIZE) && (ibs != ctx->ibuf_size)) {

      p1 = malloc(num);

      if (p1 == NULL)

        goto malloc_error;

    }

    if ((obs > DEFAULT_BUFFER_SIZE) && (obs != ctx->obuf_size)) {

      p2 = malloc(num);

      if (p2 == NULL) {

        if (p1 != ctx->ibuf)

          free(p1);

        goto malloc_error;

      }

    }

    if (ctx->ibuf != p1) {

      free(ctx->ibuf);

      ctx->ibuf = p1;

      ctx->ibuf_off = 0;

      ctx->ibuf_len = 0;

      ctx->ibuf_size = ibs;

    }

    if (ctx->obuf != p2) {

      free(ctx->obuf);

      ctx->obuf = p2;

      ctx->obuf_off = 0;

      ctx->obuf_len = 0;

      ctx->obuf_size = obs;

    }

    break;

  case BIO_C_DO_STATE_MACHINE:

    if (b->next_bio == NULL)

      return (0);

    BIO_clear_retry_flags(b);

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

    BIO_copy_next_retry(b);

    break;

  case BIO_CTRL_FLUSH:

    if (b->next_bio == NULL)

      return (0);

    if (ctx->obuf_len <= 0) {

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

      break;

    }

    for (;;) {

      BIO_clear_retry_flags(b);

      if (ctx->obuf_len > 0) {

        r = BIO_write(b->next_bio,

            &(ctx->obuf[ctx->obuf_off]),

            ctx->obuf_len);

        BIO_copy_next_retry(b);

        if (r <= 0)

          return ((long)r);

        ctx->obuf_off += r;

        ctx->obuf_len -= r;

      } else {

        ctx->obuf_len = 0;

        ctx->obuf_off = 0;

        break;

      }

    }

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

    break;

  case BIO_CTRL_DUP:

    dbio = (BIO *)ptr;

    if (!BIO_set_read_buffer_size(dbio, ctx->ibuf_size) ||

        !BIO_set_write_buffer_size(dbio, ctx->obuf_size))

      ret = 0;

    break;

  default:

    if (b->next_bio == NULL)

      return (0);

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

    break;

  }

  return (ret);

malloc_error:

  BIOerror(ERR_R_MALLOC_FAILURE);

  return (0);

}

static long

buffer_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

buffer_gets(BIO *b, char *buf, int size)

{

  BIO_F_BUFFER_CTX *ctx;

  int num = 0, i, flag;

  char *p;

  ctx = (BIO_F_BUFFER_CTX *)b->ptr;

  size--; /* reserve space for a '\0' */

  BIO_clear_retry_flags(b);

  for (;;) {

    if (ctx->ibuf_len > 0) {

      p = &(ctx->ibuf[ctx->ibuf_off]);

      flag = 0;

      for (i = 0; (i < ctx->ibuf_len) && (i < size); i++) {

        *(buf++) = p[i];

        if (p[i] == '\n') {

          flag = 1;

          i++;

          break;

        }

      }

      num += i;

      size -= i;

      ctx->ibuf_len -= i;

      ctx->ibuf_off += i;

      if (flag || size == 0) {

        *buf = '\0';

        return (num);

      }

    }

    else  /* read another chunk */

    {

      i = BIO_read(b->next_bio, ctx->ibuf, ctx->ibuf_size);

      if (i <= 0) {

        BIO_copy_next_retry(b);

        *buf = '\0';

        if (i < 0)

          return ((num > 0) ? num : i);

        if (i == 0)

          return (num);

      }

      ctx->ibuf_len = i;

      ctx->ibuf_off = 0;

    }

  }

}

static int

buffer_puts(BIO *b, const char *str)

{

  return (buffer_write(b, str, strlen(str)));

}