text: /*
   * Copyright 2008-2018 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include BOSS_OPENSSL_V_openssl__asn1_h //original-code:<openssl/asn1.h>
  #include BOSS_OPENSSL_V_openssl__asn1t_h //original-code:<openssl/asn1t.h>
  #include BOSS_OPENSSL_V_openssl__bio_h //original-code:<openssl/bio.h>
  #include BOSS_OPENSSL_V_openssl__err_h //original-code:<openssl/err.h>
  
  #include <stdio.h>
  
  /* Experimental NDEF ASN1 BIO support routines */
  
  /*
   * The usage is quite simple, initialize an ASN1 structure, get a BIO from it
   * then any data written through the BIO will end up translated to
   * appropriate format on the fly. The data is streamed out and does *not*
   * need to be all held in memory at once. When the BIO is flushed the output
   * is finalized and any signatures etc written out. The BIO is a 'proper'
   * BIO and can handle non blocking I/O correctly. The usage is simple. The
   * implementation is *not*...
   */
  
  /* BIO support data stored in the ASN1 BIO ex_arg */
  
  typedef struct ndef_aux_st {
      /* ASN1 structure this BIO refers to */
      ASN1_VALUE *val;
      const ASN1_ITEM *it;
      /* Top of the BIO chain */
      BIO *ndef_bio;
      /* Output BIO */
      BIO *out;
      /* Boundary where content is inserted */
      unsigned char **boundary;
      /* DER buffer start */
      unsigned char *derbuf;
  } NDEF_SUPPORT;
  
  static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
  static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
                              void *parg);
  static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg);
  static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
                              void *parg);
  
  BIO *BIO_new_NDEF(BIO *out, ASN1_VALUE *val, const ASN1_ITEM *it)
  {
      NDEF_SUPPORT *ndef_aux = NULL;
      BIO *asn_bio = NULL;
      const ASN1_AUX *aux = it->funcs;
      ASN1_STREAM_ARG sarg;
  
      if (!aux || !aux->asn1_cb) {
          ASN1err(ASN1_F_BIO_NEW_NDEF, ASN1_R_STREAMING_NOT_SUPPORTED);
          return NULL;
      }
      ndef_aux = OPENSSL_zalloc(sizeof(*ndef_aux));
      asn_bio = BIO_new(BIO_f_asn1());
      if (ndef_aux == NULL || asn_bio == NULL)
          goto err;
  
      /* ASN1 bio needs to be next to output BIO */
      out = BIO_push(asn_bio, out);
      if (out == NULL)
          goto err;
  
      BIO_asn1_set_prefix(asn_bio, ndef_prefix, ndef_prefix_free);
      BIO_asn1_set_suffix(asn_bio, ndef_suffix, ndef_suffix_free);
  
      /*
       * Now let callback prepends any digest, cipher etc BIOs ASN1 structure
       * needs.
       */
  
      sarg.out = out;
      sarg.ndef_bio = NULL;
      sarg.boundary = NULL;
  
      if (aux->asn1_cb(ASN1_OP_STREAM_PRE, &val, it, &sarg) <= 0)
          goto err;
  
      ndef_aux->val = val;
      ndef_aux->it = it;
      ndef_aux->ndef_bio = sarg.ndef_bio;
      ndef_aux->boundary = sarg.boundary;
      ndef_aux->out = out;
  
      BIO_ctrl(asn_bio, BIO_C_SET_EX_ARG, 0, ndef_aux);
  
      return sarg.ndef_bio;
  
   err:
      BIO_free(asn_bio);
      OPENSSL_free(ndef_aux);
      return NULL;
  }
  
  static int ndef_prefix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
  {
      NDEF_SUPPORT *ndef_aux;
      unsigned char *p;
      int derlen;
  
      if (!parg)
          return 0;
  
      ndef_aux = *(NDEF_SUPPORT **)parg;
  
      derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
      if ((p = OPENSSL_malloc(derlen)) == NULL) {
          ASN1err(ASN1_F_NDEF_PREFIX, ERR_R_MALLOC_FAILURE);
          return 0;
      }
  
      ndef_aux->derbuf = p;
      *pbuf = p;
      derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
  
      if (!*ndef_aux->boundary)
          return 0;
  
      *plen = *ndef_aux->boundary - *pbuf;
  
      return 1;
  }
  
  static int ndef_prefix_free(BIO *b, unsigned char **pbuf, int *plen,
                              void *parg)
  {
      NDEF_SUPPORT *ndef_aux;
  
      if (!parg)
          return 0;
  
      ndef_aux = *(NDEF_SUPPORT **)parg;
  
      OPENSSL_free(ndef_aux->derbuf);
  
      ndef_aux->derbuf = NULL;
      *pbuf = NULL;
      *plen = 0;
      return 1;
  }
  
  static int ndef_suffix_free(BIO *b, unsigned char **pbuf, int *plen,
                              void *parg)
  {
      NDEF_SUPPORT **pndef_aux = (NDEF_SUPPORT **)parg;
      if (!ndef_prefix_free(b, pbuf, plen, parg))
          return 0;
      OPENSSL_free(*pndef_aux);
      *pndef_aux = NULL;
      return 1;
  }
  
  static int ndef_suffix(BIO *b, unsigned char **pbuf, int *plen, void *parg)
  {
      NDEF_SUPPORT *ndef_aux;
      unsigned char *p;
      int derlen;
      const ASN1_AUX *aux;
      ASN1_STREAM_ARG sarg;
  
      if (!parg)
          return 0;
  
      ndef_aux = *(NDEF_SUPPORT **)parg;
  
      aux = ndef_aux->it->funcs;
  
      /* Finalize structures */
      sarg.ndef_bio = ndef_aux->ndef_bio;
      sarg.out = ndef_aux->out;
      sarg.boundary = ndef_aux->boundary;
      if (aux->asn1_cb(ASN1_OP_STREAM_POST,
                       &ndef_aux->val, ndef_aux->it, &sarg) <= 0)
          return 0;
  
      derlen = ASN1_item_ndef_i2d(ndef_aux->val, NULL, ndef_aux->it);
      if ((p = OPENSSL_malloc(derlen)) == NULL) {
          ASN1err(ASN1_F_NDEF_SUFFIX, ERR_R_MALLOC_FAILURE);
          return 0;
      }
  
      ndef_aux->derbuf = p;
      *pbuf = p;
      derlen = ASN1_item_ndef_i2d(ndef_aux->val, &p, ndef_aux->it);
  
      if (!*ndef_aux->boundary)
          return 0;
      *pbuf = *ndef_aux->boundary;
      *plen = derlen - (*ndef_aux->boundary - ndef_aux->derbuf);
  
      return 1;
  }
  