/* $OpenBSD: bio_asn1.c,v 1.17 2022/01/14 08:40:57 tb Exp $ */

/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL

 * project.

 */

/* ====================================================================

 * Copyright (c) 2006 The OpenSSL Project.  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. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED 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 OpenSSL PROJECT OR

 * ITS 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.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

/* Experimental ASN1 BIO. When written through the data is converted

 * to an ASN1 string type: default is OCTET STRING. Additional functions

 * can be provided to add prefix and suffix data.

 */

#include <stdlib.h>

#include <string.h>

#include <openssl/bio.h>

#include <openssl/asn1.h>

#include "bio_local.h"

/* Must be large enough for biggest tag+length */

#define DEFAULT_ASN1_BUF_SIZE 20

typedef enum {

  ASN1_STATE_START,

  ASN1_STATE_PRE_COPY,

  ASN1_STATE_HEADER,

  ASN1_STATE_HEADER_COPY,

  ASN1_STATE_DATA_COPY,

  ASN1_STATE_POST_COPY,

  ASN1_STATE_DONE

} asn1_bio_state_t;

typedef struct BIO_ASN1_EX_FUNCS_st {

  asn1_ps_func  *ex_func;

  asn1_ps_func  *ex_free_func;

} BIO_ASN1_EX_FUNCS;

typedef struct BIO_ASN1_BUF_CTX_t {

  /* Internal state */

  asn1_bio_state_t state;

  /* Internal buffer */

  unsigned char *buf;

  /* Size of buffer */

  int bufsize;

  /* Current position in buffer */

  int bufpos;

  /* Current buffer length */

  int buflen;

  /* Amount of data to copy */

  int copylen;

  /* Class and tag to use */

  int asn1_class, asn1_tag;

  asn1_ps_func *prefix, *prefix_free, *suffix, *suffix_free;

  /* Extra buffer for prefix and suffix data */

  unsigned char *ex_buf;

  int ex_len;

  int ex_pos;

  void *ex_arg;

} BIO_ASN1_BUF_CTX;

static int asn1_bio_write(BIO *h, const char *buf, int num);

static int asn1_bio_read(BIO *h, char *buf, int size);

static int asn1_bio_puts(BIO *h, const char *str);

static int asn1_bio_gets(BIO *h, char *str, int size);

static long asn1_bio_ctrl(BIO *h, int cmd, long arg1, void *arg2);

static int asn1_bio_new(BIO *h);

static int asn1_bio_free(BIO *data);

static long asn1_bio_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);

static int asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,

    asn1_ps_func *cleanup, asn1_bio_state_t next);

static int asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx,

    asn1_ps_func *setup, asn1_bio_state_t ex_state,

    asn1_bio_state_t other_state);

static const BIO_METHOD methods_asn1 = {

  .type = BIO_TYPE_ASN1,

  .name = "asn1",

  .bwrite = asn1_bio_write,

  .bread = asn1_bio_read,

  .bputs = asn1_bio_puts,

  .bgets = asn1_bio_gets,

  .ctrl = asn1_bio_ctrl,

  .create = asn1_bio_new,

  .destroy = asn1_bio_free,

  .callback_ctrl = asn1_bio_callback_ctrl

};

const BIO_METHOD *

BIO_f_asn1(void)

{

  return (&methods_asn1);

}

static int

asn1_bio_new(BIO *b)

{

  BIO_ASN1_BUF_CTX *ctx;

  if ((ctx = calloc(1, sizeof(*ctx))) == NULL)

    return 0;

  if ((ctx->buf = malloc(DEFAULT_ASN1_BUF_SIZE)) == NULL) {

    free(ctx);

    return 0;

  }

  ctx->bufsize = DEFAULT_ASN1_BUF_SIZE;

  ctx->asn1_class = V_ASN1_UNIVERSAL;

  ctx->asn1_tag = V_ASN1_OCTET_STRING;

  ctx->state = ASN1_STATE_START;

  b->init = 1;

  b->ptr = (char *)ctx;

  b->flags = 0;

  return 1;

}

static int

asn1_bio_free(BIO *b)

{

  BIO_ASN1_BUF_CTX *ctx;

  ctx = (BIO_ASN1_BUF_CTX *) b->ptr;

  if (ctx == NULL)

    return 0;

  free(ctx->buf);

  free(ctx);

  b->init = 0;

  b->ptr = NULL;

  b->flags = 0;

  return 1;

}

static int

asn1_bio_write(BIO *b, const char *in , int inl)

{

  BIO_ASN1_BUF_CTX *ctx;

  int wrmax, wrlen, ret, buflen;

  unsigned char *p;

  if (!in || (inl < 0) || (b->next_bio == NULL))

    return 0;

  ctx = (BIO_ASN1_BUF_CTX *) b->ptr;

  if (ctx == NULL)

    return 0;

  wrlen = 0;

  ret = -1;

  for (;;) {

    switch (ctx->state) {

      /* Setup prefix data, call it */

    case ASN1_STATE_START:

      if (!asn1_bio_setup_ex(b, ctx, ctx->prefix,

            ASN1_STATE_PRE_COPY, ASN1_STATE_HEADER))

        return 0;

      break;

      /* Copy any pre data first */

    case ASN1_STATE_PRE_COPY:

      ret = asn1_bio_flush_ex(b, ctx, ctx->prefix_free,

          ASN1_STATE_HEADER);

      if (ret <= 0)

        goto done;

      break;

    case ASN1_STATE_HEADER:

      buflen = ASN1_object_size(0, inl, ctx->asn1_tag) - inl;

      if (buflen <= 0 || buflen > ctx->bufsize)

        return -1;

      ctx->buflen = buflen;

      p = ctx->buf;

      ASN1_put_object(&p, 0, inl,

          ctx->asn1_tag, ctx->asn1_class);

      ctx->copylen = inl;

      ctx->state = ASN1_STATE_HEADER_COPY;

      break;

    case ASN1_STATE_HEADER_COPY:

      ret = BIO_write(b->next_bio,

          ctx->buf + ctx->bufpos, ctx->buflen);

      if (ret <= 0)

        goto done;

      ctx->buflen -= ret;

      if (ctx->buflen)

        ctx->bufpos += ret;

      else {

        ctx->bufpos = 0;

        ctx->state = ASN1_STATE_DATA_COPY;

      }

      break;

    case ASN1_STATE_DATA_COPY:

      if (inl > ctx->copylen)

        wrmax = ctx->copylen;

      else

        wrmax = inl;

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

      if (ret <= 0)

        break;

      wrlen += ret;

      ctx->copylen -= ret;

      in += ret;

      inl -= ret;

      if (ctx->copylen == 0)

        ctx->state = ASN1_STATE_HEADER;

      if (inl == 0)

        goto done;

      break;

    default:

      BIO_clear_retry_flags(b);

      return 0;

    }

  }

 done:

  BIO_clear_retry_flags(b);

  BIO_copy_next_retry(b);

  return (wrlen > 0) ? wrlen : ret;

}

static int

asn1_bio_flush_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx, asn1_ps_func *cleanup,

    asn1_bio_state_t next)

{

  int ret;

  if (ctx->ex_len <= 0)

    return 1;

  for (;;) {

    ret = BIO_write(b->next_bio, ctx->ex_buf + ctx->ex_pos,

        ctx->ex_len);

    if (ret <= 0)

      break;

    ctx->ex_len -= ret;

    if (ctx->ex_len > 0)

      ctx->ex_pos += ret;

    else {

      if (cleanup)

        cleanup(b, &ctx->ex_buf, &ctx->ex_len,

            &ctx->ex_arg);

      ctx->state = next;

      ctx->ex_pos = 0;

      break;

    }

  }

  return ret;

}

static int

asn1_bio_setup_ex(BIO *b, BIO_ASN1_BUF_CTX *ctx, asn1_ps_func *setup,

    asn1_bio_state_t ex_state, asn1_bio_state_t other_state)

{

  if (setup && !setup(b, &ctx->ex_buf, &ctx->ex_len, &ctx->ex_arg)) {

    BIO_clear_retry_flags(b);

    return 0;

  }

  if (ctx->ex_len > 0)

    ctx->state = ex_state;

  else

    ctx->state = other_state;

  return 1;

}

static int

asn1_bio_read(BIO *b, char *in , int inl)

{

  if (!b->next_bio)

    return 0;

  return BIO_read(b->next_bio, in , inl);

}

static int

asn1_bio_puts(BIO *b, const char *str)

{

  return asn1_bio_write(b, str, strlen(str));

}

static int

asn1_bio_gets(BIO *b, char *str, int size)

{

  if (!b->next_bio)

    return 0;

  return BIO_gets(b->next_bio, str , size);

}

static long

asn1_bio_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)

{

  if (b->next_bio == NULL)

    return (0);

  return BIO_callback_ctrl(b->next_bio, cmd, fp);

}

static long

asn1_bio_ctrl(BIO *b, int cmd, long arg1, void *arg2)

{

  BIO_ASN1_BUF_CTX *ctx;

  BIO_ASN1_EX_FUNCS *ex_func;

  long ret = 1;

  ctx = (BIO_ASN1_BUF_CTX *) b->ptr;

  if (ctx == NULL)

    return 0;

  switch (cmd) {

  case BIO_C_SET_PREFIX:

    ex_func = arg2;

    ctx->prefix = ex_func->ex_func;

    ctx->prefix_free = ex_func->ex_free_func;

    break;

  case BIO_C_GET_PREFIX:

    ex_func = arg2;

    ex_func->ex_func = ctx->prefix;

    ex_func->ex_free_func = ctx->prefix_free;

    break;

  case BIO_C_SET_SUFFIX:

    ex_func = arg2;

    ctx->suffix = ex_func->ex_func;

    ctx->suffix_free = ex_func->ex_free_func;

    break;

  case BIO_C_GET_SUFFIX:

    ex_func = arg2;

    ex_func->ex_func = ctx->suffix;

    ex_func->ex_free_func = ctx->suffix_free;

    break;

  case BIO_C_SET_EX_ARG:

    ctx->ex_arg = arg2;

    break;

  case BIO_C_GET_EX_ARG:

    *(void **)arg2 = ctx->ex_arg;

    break;

  case BIO_CTRL_FLUSH:

    if (!b->next_bio)

      return 0;

    /* Call post function if possible */

    if (ctx->state == ASN1_STATE_HEADER) {

      if (!asn1_bio_setup_ex(b, ctx, ctx->suffix,

          ASN1_STATE_POST_COPY, ASN1_STATE_DONE))

        return 0;

    }

    if (ctx->state == ASN1_STATE_POST_COPY) {

      ret = asn1_bio_flush_ex(b, ctx, ctx->suffix_free,

          ASN1_STATE_DONE);

      if (ret <= 0)

        return ret;

    }

    if (ctx->state == ASN1_STATE_DONE)

      return BIO_ctrl(b->next_bio, cmd, arg1, arg2);

    else {

      BIO_clear_retry_flags(b);

      return 0;

    }

    break;

  default:

    if (!b->next_bio)

      return 0;

    return BIO_ctrl(b->next_bio, cmd, arg1, arg2);

  }

  return ret;

}

static int

asn1_bio_set_ex(BIO *b, int cmd, asn1_ps_func *ex_func, asn1_ps_func

    *ex_free_func)

{

  BIO_ASN1_EX_FUNCS extmp;

  extmp.ex_func = ex_func;

  extmp.ex_free_func = ex_free_func;

  return BIO_ctrl(b, cmd, 0, &extmp);

}

static int

asn1_bio_get_ex(BIO *b, int cmd, asn1_ps_func **ex_func,

    asn1_ps_func **ex_free_func)

{

  BIO_ASN1_EX_FUNCS extmp;

  int ret;

  ret = BIO_ctrl(b, cmd, 0, &extmp);

  if (ret > 0) {

    *ex_func = extmp.ex_func;

    *ex_free_func = extmp.ex_free_func;

  }

  return ret;

}

int

BIO_asn1_set_prefix(BIO *b, asn1_ps_func *prefix, asn1_ps_func *prefix_free)

{

  return asn1_bio_set_ex(b, BIO_C_SET_PREFIX, prefix, prefix_free);

}

int

BIO_asn1_get_prefix(BIO *b, asn1_ps_func **pprefix, asn1_ps_func **pprefix_free)

{

  return asn1_bio_get_ex(b, BIO_C_GET_PREFIX, pprefix, pprefix_free);

}

int

BIO_asn1_set_suffix(BIO *b, asn1_ps_func *suffix, asn1_ps_func *suffix_free)

{

  return asn1_bio_set_ex(b, BIO_C_SET_SUFFIX, suffix, suffix_free);

}

int

BIO_asn1_get_suffix(BIO *b, asn1_ps_func **psuffix, asn1_ps_func **psuffix_free)

{

  return asn1_bio_get_ex(b, BIO_C_GET_SUFFIX, psuffix, psuffix_free);

}