/* 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 <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/bytestring.h>
#include <openssl/err.h>
#include <openssl/mem.h>

#include <limits.h>
#include <string.h>

#include "../internal.h"
#include "internal.h"

/*
 * Constructed types with a recursive definition (such as can be found in PKCS7)
 * could eventually exceed the stack given malicious input with excessive
 * recursion. Therefore we limit the stack depth. This is the maximum number of
 * recursive invocations of asn1_item_embed_d2i().
 */
#define ASN1_MAX_CONSTRUCTED_NEST 30

static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
                           char *cst, const unsigned char **in, long len,
                           int exptag, int expclass, char opt);

static int asn1_template_ex_d2i(ASN1_VALUE **pval, const unsigned char **in,
                                long len, const ASN1_TEMPLATE *tt, char opt,
                                int depth);
static int asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in,
                                   long len, const ASN1_TEMPLATE *tt, char opt,
                                   int depth);
static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
                       int utype, const ASN1_ITEM *it);
static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in,
                                 long len, const ASN1_ITEM *it, int tag,
                                 int aclass, char opt);
static int asn1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in,
                            long len, const ASN1_ITEM *it, int tag, int aclass,
                            char opt, int depth);

/* Table to convert tags to bit values, used for MSTRING type */
static const unsigned long tag2bit[31] = {
    0, /* (reserved) */
    0, /* BOOLEAN */
    0, /* INTEGER */
    B_ASN1_BIT_STRING,
    B_ASN1_OCTET_STRING,
    0,              /* NULL */
    0,              /* OBJECT IDENTIFIER */
    B_ASN1_UNKNOWN, /* ObjectDescriptor */
    B_ASN1_UNKNOWN, /* EXTERNAL */
    B_ASN1_UNKNOWN, /* REAL */
    B_ASN1_UNKNOWN, /* ENUMERATED */
    B_ASN1_UNKNOWN, /* EMBEDDED PDV */
    B_ASN1_UTF8STRING,
    B_ASN1_UNKNOWN, /* RELATIVE-OID */
    B_ASN1_UNKNOWN, /* TIME */
    B_ASN1_UNKNOWN, /* (reserved) */
    B_ASN1_SEQUENCE,
    0, /* SET */
    B_ASN1_NUMERICSTRING,
    B_ASN1_PRINTABLESTRING,
    B_ASN1_T61STRING,
    B_ASN1_VIDEOTEXSTRING,
    B_ASN1_IA5STRING,
    B_ASN1_UTCTIME,
    B_ASN1_GENERALIZEDTIME,
    B_ASN1_GRAPHICSTRING,
    B_ASN1_ISO64STRING,
    B_ASN1_GENERALSTRING,
    B_ASN1_UNIVERSALSTRING,
    B_ASN1_UNKNOWN, /* CHARACTER STRING */
    B_ASN1_BMPSTRING,
};

unsigned long ASN1_tag2bit(int tag) {
  if (tag < 0 || tag > 30)
    return 0;
  return tag2bit[tag];
}

/* Macro to initialize and invalidate the cache */

/*
 * Decode an ASN1 item, this currently behaves just like a standard 'd2i'
 * function. 'in' points to a buffer to read the data from, in future we
 * will have more advanced versions that can input data a piece at a time and
 * this will simply be a special case.
 */

ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
                          const ASN1_ITEM *it) {
  ASN1_VALUE *ptmpval = NULL;
  if (!pval)
    pval = &ptmpval;

  if (asn1_item_ex_d2i(pval, in, len, it, -1, 0, 0, 0) > 0)
    return *pval;
  return NULL;
}

/*
 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
 * tag mismatch return -1 to handle OPTIONAL
 */

static int asn1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in,
                            long len, const ASN1_ITEM *it, int tag, int aclass,
                            char opt, int depth) {
  const ASN1_TEMPLATE *tt, *errtt = NULL;
  const ASN1_EXTERN_FUNCS *ef;
  const unsigned char *p = NULL, *q;
  unsigned char oclass;
  char cst, isopt;
  int i;
  int otag;
  int ret = 0;
  ASN1_VALUE **pchptr;
  int combine = aclass & ASN1_TFLG_COMBINE;
  aclass &= ~ASN1_TFLG_COMBINE;
  if (!pval)
    return 0;

  /*
   * Bound |len| to comfortably fit in an int. Lengths in this module often
   * switch between int and long without overflow checks.
   */
  if (len > INT_MAX / 2) {
    len = INT_MAX / 2;
  }

  if (++depth > ASN1_MAX_CONSTRUCTED_NEST) {
    OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_TOO_DEEP);
    goto err;
  }

  switch (it->itype) {
    case ASN1_ITYPE_PRIMITIVE:
      if (it->templates) {
        /*
         * tagging or OPTIONAL is currently illegal on an item template
         * because the flags can't get passed down. In practice this
         * isn't a problem: we include the relevant flags from the item
         * template in the template itself.
         */
        if ((tag != -1) || opt) {
          OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
          goto err;
        }
        return asn1_template_ex_d2i(pval, in, len, it->templates, opt, depth);
      }
      return asn1_d2i_ex_primitive(pval, in, len, it, tag, aclass, opt);
      break;

    case ASN1_ITYPE_MSTRING:
      /*
       * It never makes sense for multi-strings to have implicit tagging, so
       * if tag != -1, then this looks like an error in the template.
       */
      if (tag != -1) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_TEMPLATE);
        goto err;
      }

      p = *in;
      /* Just read in tag and class */
      ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, &p, len, -1, 0, 1);
      if (!ret) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
        goto err;
      }

      /* Must be UNIVERSAL class */
      if (oclass != V_ASN1_UNIVERSAL) {
        /* If OPTIONAL, assume this is OK */
        if (opt)
          return -1;
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_MSTRING_NOT_UNIVERSAL);
        goto err;
      }
      /* Check tag matches bit map */
      if (!(ASN1_tag2bit(otag) & it->utype)) {
        /* If OPTIONAL, assume this is OK */
        if (opt)
          return -1;
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_MSTRING_WRONG_TAG);
        goto err;
      }
      return asn1_d2i_ex_primitive(pval, in, len, it, otag, 0, 0);

    case ASN1_ITYPE_EXTERN:
      /* Use new style d2i */
      ef = it->funcs;
      return ef->asn1_ex_d2i(pval, in, len, it, tag, aclass, opt, NULL);

    case ASN1_ITYPE_CHOICE: {
      /*
       * It never makes sense for CHOICE types to have implicit tagging, so if
       * tag != -1, then this looks like an error in the template.
       */
      if (tag != -1) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_TEMPLATE);
        goto err;
      }

      const ASN1_AUX *aux = it->funcs;
      ASN1_aux_cb *asn1_cb = aux != NULL ? aux->asn1_cb : NULL;
      if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
        goto auxerr;

      if (*pval) {
        /* Free up and zero CHOICE value if initialised */
        i = asn1_get_choice_selector(pval, it);
        if ((i >= 0) && (i < it->tcount)) {
          tt = it->templates + i;
          pchptr = asn1_get_field_ptr(pval, tt);
          ASN1_template_free(pchptr, tt);
          asn1_set_choice_selector(pval, -1, it);
        }
      } else if (!ASN1_item_ex_new(pval, it)) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
        goto err;
      }
      /* CHOICE type, try each possibility in turn */
      p = *in;
      for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
        pchptr = asn1_get_field_ptr(pval, tt);
        /*
         * We mark field as OPTIONAL so its absence can be recognised.
         */
        ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, depth);
        /* If field not present, try the next one */
        if (ret == -1)
          continue;
        /* If positive return, read OK, break loop */
        if (ret > 0)
          break;
        /* Otherwise must be an ASN1 parsing error */
        errtt = tt;
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
        goto err;
      }

      /* Did we fall off the end without reading anything? */
      if (i == it->tcount) {
        /* If OPTIONAL, this is OK */
        if (opt) {
          /* Free and zero it */
          ASN1_item_ex_free(pval, it);
          return -1;
        }
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_NO_MATCHING_CHOICE_TYPE);
        goto err;
      }

      asn1_set_choice_selector(pval, i, it);
      if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
        goto auxerr;
      *in = p;
      return 1;
    }

    case ASN1_ITYPE_SEQUENCE: {
      p = *in;

      /* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
      if (tag == -1) {
        tag = V_ASN1_SEQUENCE;
        aclass = V_ASN1_UNIVERSAL;
      }
      /* Get SEQUENCE length and update len, p */
      ret = asn1_check_tlen(&len, NULL, NULL, &cst, &p, len, tag, aclass, opt);
      if (!ret) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
        goto err;
      } else if (ret == -1)
        return -1;
      if (!cst) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
        goto err;
      }

      if (!*pval && !ASN1_item_ex_new(pval, it)) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
        goto err;
      }

      const ASN1_AUX *aux = it->funcs;
      ASN1_aux_cb *asn1_cb = aux != NULL ? aux->asn1_cb : NULL;
      if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
        goto auxerr;

      /* Free up and zero any ADB found */
      for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
        if (tt->flags & ASN1_TFLG_ADB_MASK) {
          const ASN1_TEMPLATE *seqtt;
          ASN1_VALUE **pseqval;
          seqtt = asn1_do_adb(pval, tt, 0);
          if (seqtt == NULL)
            continue;
          pseqval = asn1_get_field_ptr(pval, seqtt);
          ASN1_template_free(pseqval, seqtt);
        }
      }

      /* Get each field entry */
      for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
        const ASN1_TEMPLATE *seqtt;
        ASN1_VALUE **pseqval;
        seqtt = asn1_do_adb(pval, tt, 1);
        if (seqtt == NULL)
          goto err;
        pseqval = asn1_get_field_ptr(pval, seqtt);
        /* Have we ran out of data? */
        if (!len)
          break;
        q = p;
        /*
         * This determines the OPTIONAL flag value. The field cannot be
         * omitted if it is the last of a SEQUENCE and there is still
         * data to be read. This isn't strictly necessary but it
         * increases efficiency in some cases.
         */
        if (i == (it->tcount - 1))
          isopt = 0;
        else
          isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
        /*
         * attempt to read in field, allowing each to be OPTIONAL
         */

        ret = asn1_template_ex_d2i(pseqval, &p, len, seqtt, isopt, depth);
        if (!ret) {
          errtt = seqtt;
          goto err;
        } else if (ret == -1) {
          /*
           * OPTIONAL component absent. Free and zero the field.
           */
          ASN1_template_free(pseqval, seqtt);
          continue;
        }
        /* Update length */
        len -= p - q;
      }

      /* Check all data read */
      if (len) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_SEQUENCE_LENGTH_MISMATCH);
        goto err;
      }

      /*
       * If we get here we've got no more data in the SEQUENCE, however we
       * may not have read all fields so check all remaining are OPTIONAL
       * and clear any that are.
       */
      for (; i < it->tcount; tt++, i++) {
        const ASN1_TEMPLATE *seqtt;
        seqtt = asn1_do_adb(pval, tt, 1);
        if (seqtt == NULL)
          goto err;
        if (seqtt->flags & ASN1_TFLG_OPTIONAL) {
          ASN1_VALUE **pseqval;
          pseqval = asn1_get_field_ptr(pval, seqtt);
          ASN1_template_free(pseqval, seqtt);
        } else {
          errtt = seqtt;
          OPENSSL_PUT_ERROR(ASN1, ASN1_R_FIELD_MISSING);
          goto err;
        }
      }
      /* Save encoding */
      if (!asn1_enc_save(pval, *in, p - *in, it))
        goto auxerr;
      if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
        goto auxerr;
      *in = p;
      return 1;
    }

    default:
      return 0;
  }
auxerr:
  OPENSSL_PUT_ERROR(ASN1, ASN1_R_AUX_ERROR);
err:
  if (combine == 0)
    ASN1_item_ex_free(pval, it);
  if (errtt)
    ERR_add_error_data(4, "Field=", errtt->field_name, ", Type=", it->sname);
  else
    ERR_add_error_data(2, "Type=", it->sname);
  return 0;
}

int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
                     const ASN1_ITEM *it, int tag, int aclass, char opt,
                     ASN1_TLC *ctx) {
  return asn1_item_ex_d2i(pval, in, len, it, tag, aclass, opt, 0);
}

/*
 * Templates are handled with two separate functions. One handles any
 * EXPLICIT tag and the other handles the rest.
 */

static int asn1_template_ex_d2i(ASN1_VALUE **val, const unsigned char **in,
                                long inlen, const ASN1_TEMPLATE *tt, char opt,
                                int depth) {
  int flags, aclass;
  int ret;
  long len;
  const unsigned char *p, *q;
  if (!val)
    return 0;
  flags = tt->flags;
  aclass = flags & ASN1_TFLG_TAG_CLASS;

  p = *in;

  /* Check if EXPLICIT tag expected */
  if (flags & ASN1_TFLG_EXPTAG) {
    char cst;
    /*
     * Need to work out amount of data available to the inner content and
     * where it starts: so read in EXPLICIT header to get the info.
     */
    ret = asn1_check_tlen(&len, NULL, NULL, &cst, &p, inlen, tt->tag, aclass,
                          opt);
    q = p;
    if (!ret) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
      return 0;
    } else if (ret == -1)
      return -1;
    if (!cst) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
      return 0;
    }
    /* We've found the field so it can't be OPTIONAL now */
    ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, depth);
    if (!ret) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
      return 0;
    }
    /* We read the field in OK so update length */
    len -= p - q;
    /* Check for trailing data. */
    if (len) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_EXPLICIT_LENGTH_MISMATCH);
      goto err;
    }
  } else
    return asn1_template_noexp_d2i(val, in, inlen, tt, opt, depth);

  *in = p;
  return 1;

err:
  ASN1_template_free(val, tt);
  return 0;
}

static int asn1_template_noexp_d2i(ASN1_VALUE **val, const unsigned char **in,
                                   long len, const ASN1_TEMPLATE *tt, char opt,
                                   int depth) {
  int flags, aclass;
  int ret;
  const unsigned char *p;
  if (!val)
    return 0;
  flags = tt->flags;
  aclass = flags & ASN1_TFLG_TAG_CLASS;

  p = *in;

  if (flags & ASN1_TFLG_SK_MASK) {
    /* SET OF, SEQUENCE OF */
    int sktag, skaclass;
    /* First work out expected inner tag value */
    if (flags & ASN1_TFLG_IMPTAG) {
      sktag = tt->tag;
      skaclass = aclass;
    } else {
      skaclass = V_ASN1_UNIVERSAL;
      if (flags & ASN1_TFLG_SET_OF)
        sktag = V_ASN1_SET;
      else
        sktag = V_ASN1_SEQUENCE;
    }
    /* Get the tag */
    ret =
        asn1_check_tlen(&len, NULL, NULL, NULL, &p, len, sktag, skaclass, opt);
    if (!ret) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
      return 0;
    } else if (ret == -1)
      return -1;
    if (!*val)
      *val = (ASN1_VALUE *)sk_ASN1_VALUE_new_null();
    else {
      /*
       * We've got a valid STACK: free up any items present
       */
      STACK_OF(ASN1_VALUE) *sktmp = (STACK_OF(ASN1_VALUE) *)*val;
      ASN1_VALUE *vtmp;
      while (sk_ASN1_VALUE_num(sktmp) > 0) {
        vtmp = sk_ASN1_VALUE_pop(sktmp);
        ASN1_item_ex_free(&vtmp, ASN1_ITEM_ptr(tt->item));
      }
    }

    if (!*val) {
      OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
      goto err;
    }

    /* Read as many items as we can */
    while (len > 0) {
      ASN1_VALUE *skfield;
      const unsigned char *q = p;
      skfield = NULL;
      if (!asn1_item_ex_d2i(&skfield, &p, len, ASN1_ITEM_ptr(tt->item), -1, 0,
                            0, depth)) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
        goto err;
      }
      len -= p - q;
      if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val, skfield)) {
        ASN1_item_ex_free(&skfield, ASN1_ITEM_ptr(tt->item));
        OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
        goto err;
      }
    }
  } else if (flags & ASN1_TFLG_IMPTAG) {
    /* IMPLICIT tagging */
    ret = asn1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), tt->tag,
                           aclass, opt, depth);
    if (!ret) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
      goto err;
    } else if (ret == -1)
      return -1;
  } else {
    /* Nothing special */
    ret = asn1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item), -1,
                           tt->flags & ASN1_TFLG_COMBINE, opt, depth);
    if (!ret) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
      goto err;
    } else if (ret == -1)
      return -1;
  }

  *in = p;
  return 1;

err:
  ASN1_template_free(val, tt);
  return 0;
}

static int asn1_d2i_ex_primitive(ASN1_VALUE **pval, const unsigned char **in,
                                 long inlen, const ASN1_ITEM *it, int tag,
                                 int aclass, char opt) {
  int ret = 0, utype;
  long plen;
  char cst;
  const unsigned char *p;
  const unsigned char *cont = NULL;
  long len;
  if (!pval) {
    OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_NULL);
    return 0; /* Should never happen */
  }

  if (it->itype == ASN1_ITYPE_MSTRING) {
    utype = tag;
    tag = -1;
  } else
    utype = it->utype;

  if (utype == V_ASN1_ANY) {
    /* If type is ANY need to figure out type from tag */
    unsigned char oclass;
    if (tag >= 0) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_TAGGED_ANY);
      return 0;
    }
    if (opt) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_ILLEGAL_OPTIONAL_ANY);
      return 0;
    }
    p = *in;
    ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, &p, inlen, -1, 0, 0);
    if (!ret) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
      return 0;
    }
    if (oclass != V_ASN1_UNIVERSAL)
      utype = V_ASN1_OTHER;
  }
  if (tag == -1) {
    tag = utype;
    aclass = V_ASN1_UNIVERSAL;
  }
  p = *in;
  /* Check header */
  ret = asn1_check_tlen(&plen, NULL, NULL, &cst, &p, inlen, tag, aclass, opt);
  if (!ret) {
    OPENSSL_PUT_ERROR(ASN1, ASN1_R_NESTED_ASN1_ERROR);
    return 0;
  } else if (ret == -1)
    return -1;
  ret = 0;
  /* SEQUENCE, SET and "OTHER" are left in encoded form */
  if ((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) ||
      (utype == V_ASN1_OTHER)) {
    /* SEQUENCE and SET must be constructed */
    if (utype != V_ASN1_OTHER && !cst) {
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_TYPE_NOT_CONSTRUCTED);
      return 0;
    }

    cont = *in;
    len = p - cont + plen;
    p += plen;
  } else if (cst) {
    /* This parser historically supported BER constructed strings. We no
     * longer do and will gradually tighten this parser into a DER
     * parser. BER types should use |CBS_asn1_ber_to_der|. */
    OPENSSL_PUT_ERROR(ASN1, ASN1_R_TYPE_NOT_PRIMITIVE);
    return 0;
  } else {
    cont = p;
    len = plen;
    p += plen;
  }

  /* We now have content length and type: translate into a structure */
  if (!asn1_ex_c2i(pval, cont, len, utype, it))
    goto err;

  *in = p;
  ret = 1;
err:
  return ret;
}

/* Translate ASN1 content octets into a structure */

static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
                       int utype, const ASN1_ITEM *it) {
  ASN1_VALUE **opval = NULL;
  ASN1_STRING *stmp;
  ASN1_TYPE *typ = NULL;
  int ret = 0;
  ASN1_INTEGER **tint;

  /* Historically, |it->funcs| for primitive types contained an
   * |ASN1_PRIMITIVE_FUNCS| table of callbacks. */
  assert(it->funcs == NULL);

  /* If ANY type clear type and set pointer to internal value */
  if (it->utype == V_ASN1_ANY) {
    if (!*pval) {
      typ = ASN1_TYPE_new();
      if (typ == NULL)
        goto err;
      *pval = (ASN1_VALUE *)typ;
    } else
      typ = (ASN1_TYPE *)*pval;

    if (utype != typ->type)
      ASN1_TYPE_set(typ, utype, NULL);
    opval = pval;
    pval = &typ->value.asn1_value;
  }
  switch (utype) {
    case V_ASN1_OBJECT:
      if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
        goto err;
      break;

    case V_ASN1_NULL:
      if (len) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_NULL_IS_WRONG_LENGTH);
        goto err;
      }
      *pval = (ASN1_VALUE *)1;
      break;

    case V_ASN1_BOOLEAN:
      if (len != 1) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
        goto err;
      } else {
        ASN1_BOOLEAN *tbool;
        tbool = (ASN1_BOOLEAN *)pval;
        *tbool = *cont;
      }
      break;

    case V_ASN1_BIT_STRING:
      if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
        goto err;
      break;

    case V_ASN1_INTEGER:
    case V_ASN1_ENUMERATED:
      tint = (ASN1_INTEGER **)pval;
      if (!c2i_ASN1_INTEGER(tint, &cont, len))
        goto err;
      /* Fixup type to match the expected form */
      (*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
      break;

    case V_ASN1_OCTET_STRING:
    case V_ASN1_NUMERICSTRING:
    case V_ASN1_PRINTABLESTRING:
    case V_ASN1_T61STRING:
    case V_ASN1_VIDEOTEXSTRING:
    case V_ASN1_IA5STRING:
    case V_ASN1_UTCTIME:
    case V_ASN1_GENERALIZEDTIME:
    case V_ASN1_GRAPHICSTRING:
    case V_ASN1_VISIBLESTRING:
    case V_ASN1_GENERALSTRING:
    case V_ASN1_UNIVERSALSTRING:
    case V_ASN1_BMPSTRING:
    case V_ASN1_UTF8STRING:
    case V_ASN1_OTHER:
    case V_ASN1_SET:
    case V_ASN1_SEQUENCE:
    default:
      if (utype == V_ASN1_BMPSTRING && (len & 1)) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
        goto err;
      }
      if (utype == V_ASN1_UNIVERSALSTRING && (len & 3)) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
        goto err;
      }
      if (utype == V_ASN1_UTCTIME) {
        CBS cbs;
        CBS_init(&cbs, cont, (size_t)len);
        if (!CBS_parse_utc_time(&cbs, NULL, /*allow_timezone_offset=*/1)) {
          OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_TIME_FORMAT);
          goto err;
        }
      }
      if (utype == V_ASN1_GENERALIZEDTIME) {
        CBS cbs;
        CBS_init(&cbs, cont, (size_t)len);
        if (!CBS_parse_generalized_time(&cbs, NULL,
                                        /*allow_timezone_offset=*/0)) {
          OPENSSL_PUT_ERROR(ASN1, ASN1_R_INVALID_TIME_FORMAT);
          goto err;
        }
      }
      /* All based on ASN1_STRING and handled the same */
      if (!*pval) {
        stmp = ASN1_STRING_type_new(utype);
        if (!stmp) {
          OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
          goto err;
        }
        *pval = (ASN1_VALUE *)stmp;
      } else {
        stmp = (ASN1_STRING *)*pval;
        stmp->type = utype;
      }
      if (!ASN1_STRING_set(stmp, cont, len)) {
        OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
        ASN1_STRING_free(stmp);
        *pval = NULL;
        goto err;
      }
      break;
  }
  /* If ASN1_ANY and NULL type fix up value */
  if (typ && (utype == V_ASN1_NULL))
    typ->value.ptr = NULL;

  ret = 1;
err:
  if (!ret) {
    ASN1_TYPE_free(typ);
    if (opval)
      *opval = NULL;
  }
  return ret;
}

/*
 * Check an ASN1 tag and length: a bit like ASN1_get_object but it
 * checks the expected tag.
 */

static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
                           char *cst, const unsigned char **in, long len,
                           int exptag, int expclass, char opt) {
  int i;
  int ptag, pclass;
  long plen;
  const unsigned char *p;
  p = *in;

  i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
  if (i & 0x80) {
    OPENSSL_PUT_ERROR(ASN1, ASN1_R_BAD_OBJECT_HEADER);
    return 0;
  }
  if (exptag >= 0) {
    if ((exptag != ptag) || (expclass != pclass)) {
      /*
       * If type is OPTIONAL, not an error: indicate missing type.
       */
      if (opt)
        return -1;
      OPENSSL_PUT_ERROR(ASN1, ASN1_R_WRONG_TAG);
      return 0;
    }
  }

  if (cst)
    *cst = i & V_ASN1_CONSTRUCTED;

  if (olen)
    *olen = plen;

  if (oclass)
    *oclass = pclass;

  if (otag)
    *otag = ptag;

  *in = p;
  return 1;
}