/src/libressl/crypto/asn1/tasn_dec.c

Source (jump to first uncovered line)
/* $OpenBSD: tasn_dec.c,v 1.78 2022/06/29 08:56:44 beck Exp $ */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * Copyright (c) 2000-2005 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).
 *
 */

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

#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/buffer.h>
#include <openssl/err.h>
#include <openssl/objects.h>

#include "asn1_locl.h"
#include "bytestring.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.
 */
#define ASN1_MAX_CONSTRUCTED_NEST 30

#ifndef ASN1_MAX_STRING_NEST
/*
 * This determines how many levels of recursion are permitted in ASN.1 string
 * types. If it is not limited stack overflows can occur. If set to zero no
 * recursion is allowed at all.
 */
#define ASN1_MAX_STRING_NEST 5
#endif

static int asn1_template_d2i(ASN1_VALUE **pval, CBS *cbs,
    const ASN1_TEMPLATE *at, int optional, int depth);

static int
asn1_check_eoc(CBS *cbs)
{
  uint16_t eoc;

  if (!CBS_peek_u16(cbs, &eoc))
    return 0;
  if (eoc != 0)
    return 0;

  return CBS_skip(cbs, 2);
}

static int
asn1_check_tag(CBS *cbs, size_t *out_len, int *out_tag, uint8_t *out_class,
    int *out_indefinite, int *out_constructed, int expected_tag,
    int expected_class, int optional)
{
  int constructed, indefinite;
  uint32_t tag_number;
  uint8_t tag_class;
  size_t length;

  if (out_len != NULL)
    *out_len = 0;
  if (out_tag != NULL)
    *out_tag = 0;
  if (out_class != NULL)
    *out_class = 0;
  if (out_indefinite != NULL)
    *out_indefinite = 0;
  if (out_constructed != NULL)
    *out_constructed = 0;

  if (!asn1_get_identifier_cbs(cbs, 0, &tag_class, &constructed,
      &tag_number)) {
    ASN1error(ASN1_R_BAD_OBJECT_HEADER);
    return 0;
  }
  if (expected_tag >= 0) {
    if (expected_tag != tag_number ||
        expected_class != tag_class << 6) {
      /* Indicate missing type if this is OPTIONAL. */
      if (optional)
        return -1;

      ASN1error(ASN1_R_WRONG_TAG);
      return 0;
    }
  }
  if (!asn1_get_length_cbs(cbs, 0, &indefinite, &length)) {
    ASN1error(ASN1_R_BAD_OBJECT_HEADER);
    return 0;
  }

  /* Indefinite length can only be used with constructed encoding. */
  if (indefinite && !constructed) {
    ASN1error(ASN1_R_BAD_OBJECT_HEADER);
    return 0;
  }

  if (!indefinite && CBS_len(cbs) < length) {
    ASN1error(ASN1_R_TOO_LONG);
    return 0;
  }

  if (tag_number > INT_MAX) {
    ASN1error(ASN1_R_TOO_LONG);
    return 0;
  }

  if (indefinite)
    length = CBS_len(cbs);

  if (out_len != NULL)
    *out_len = length;
  if (out_tag != NULL)
    *out_tag = tag_number;
  if (out_class != NULL)
    *out_class = tag_class << 6;
  if (out_indefinite != NULL)
    *out_indefinite = indefinite;
  if (out_constructed != NULL)
    *out_constructed = constructed;

  return 1;
}

/* Collect the contents from a constructed ASN.1 object. */
static int
asn1_collect(CBB *cbb, CBS *cbs, int indefinite, int expected_tag,
    int expected_class, int depth)
{
  int constructed;
  size_t length;
  CBS content;
  int need_eoc;

  if (depth > ASN1_MAX_STRING_NEST) {
    ASN1error(ASN1_R_NESTED_ASN1_STRING);
    return 0;
  }

  need_eoc = indefinite;

  while (CBS_len(cbs) > 0) {
    if (asn1_check_eoc(cbs)) {
      if (!need_eoc) {
        ASN1error(ASN1_R_UNEXPECTED_EOC);
        return 0;
      }
      return 1;
    }
    if (!asn1_check_tag(cbs, &length, NULL, NULL, &indefinite,
        &constructed, expected_tag, expected_class, 0)) {
      ASN1error(ERR_R_NESTED_ASN1_ERROR);
      return 0;
    }

    if (constructed) {
      if (!asn1_collect(cbb, cbs, indefinite, expected_tag,
          expected_class, depth + 1))
        return 0;
      continue;
    }

    if (!CBS_get_bytes(cbs, &content, length)) {
      ASN1error(ERR_R_NESTED_ASN1_ERROR);
      return 0;
    }
    if (!CBB_add_bytes(cbb, CBS_data(&content), CBS_len(&content)))
      return 0;
  }

  if (need_eoc) {
    ASN1error(ASN1_R_MISSING_EOC);
    return 0;
  }

  return 1;
}

/* Find the end of an ASN.1 object. */
static int
asn1_find_end(CBS *cbs, size_t length, int indefinite)
{
  size_t eoc_count;

  if (!indefinite) {
    if (!CBS_skip(cbs, length)) {
      ASN1error(ERR_R_NESTED_ASN1_ERROR);
      return 0;
    }
    return 1;
  }

  eoc_count = 1;

  while (CBS_len(cbs) > 0) {
    if (asn1_check_eoc(cbs)) {
      if (--eoc_count == 0)
        break;
      continue;
    }
    if (!asn1_check_tag(cbs, &length, NULL, NULL,
        &indefinite, NULL, -1, 0, 0)) {
      ASN1error(ERR_R_NESTED_ASN1_ERROR);
      return 0;
    }
    if (indefinite) {
      eoc_count++;
      continue;
    }
    if (!CBS_skip(cbs, length))
      return 0;
  }

  if (eoc_count > 0) {
    ASN1error(ASN1_R_MISSING_EOC);
    return 0;
  }

  return 1;
}

static int
asn1_c2i_primitive(ASN1_VALUE **pval, CBS *content, int utype, const ASN1_ITEM *it)
{
  ASN1_STRING *stmp;
  ASN1_INTEGER **tint;
  ASN1_BOOLEAN *tbool;
  uint8_t u8val;
  int ret = 0;

  if (it->funcs != NULL)
    return 0;

  if (CBS_len(content) > INT_MAX)
    return 0;

  switch (utype) {
  case V_ASN1_OBJECT:
    if (!c2i_ASN1_OBJECT_cbs((ASN1_OBJECT **)pval, content))
      goto err;
    break;

  case V_ASN1_NULL:
    if (CBS_len(content) != 0) {
      ASN1error(ASN1_R_NULL_IS_WRONG_LENGTH);
      goto err;
    }
    *pval = (ASN1_VALUE *)1;
    break;

  case V_ASN1_BOOLEAN:
    tbool = (ASN1_BOOLEAN *)pval;
    if (CBS_len(content) != 1) {
      ASN1error(ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
      goto err;
    }
    if (!CBS_get_u8(content, &u8val))
      goto err;
    *tbool = u8val;
    break;

  case V_ASN1_BIT_STRING:
    if (!c2i_ASN1_BIT_STRING_cbs((ASN1_BIT_STRING **)pval, content))
      goto err;
    break;

  case V_ASN1_INTEGER:
  case V_ASN1_ENUMERATED:
    tint = (ASN1_INTEGER **)pval;
    if (!c2i_ASN1_INTEGER_cbs(tint, content))
      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 && (CBS_len(content) & 1)) {
      ASN1error(ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
      goto err;
    }
    if (utype == V_ASN1_UNIVERSALSTRING && (CBS_len(content) & 3)) {
      ASN1error(ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
      goto err;
    }
    if (utype == V_ASN1_UTCTIME || utype == V_ASN1_GENERALIZEDTIME) {
      if (!asn1_time_parse_cbs(content,
          utype == V_ASN1_GENERALIZEDTIME, NULL))  {
        ASN1error(ASN1_R_INVALID_TIME_FORMAT);
        goto err;
      }
    }
    /* All based on ASN1_STRING and handled the same way. */
    if (*pval == NULL) {
      if ((stmp = ASN1_STRING_type_new(utype)) == NULL) {
        ASN1error(ERR_R_MALLOC_FAILURE);
        goto err;
      }
      *pval = (ASN1_VALUE *)stmp;
    } else {
      stmp = (ASN1_STRING *)*pval;
      stmp->type = utype;
    }
    if (!ASN1_STRING_set(stmp, CBS_data(content), CBS_len(content))) {
      ASN1_STRING_free(stmp);
      *pval = NULL;
      goto err;
    }
    break;
  }

  ret = 1;

 err:
  return ret;
}

static int
asn1_c2i_any(ASN1_VALUE **pval, CBS *content, int utype, const ASN1_ITEM *it)
{
  ASN1_TYPE *atype;

  if (it->utype != V_ASN1_ANY || it->funcs != NULL)
    return 0;

  if (*pval != NULL) {
    ASN1_TYPE_free((ASN1_TYPE *)*pval);
    *pval = NULL;
  }

  if ((atype = ASN1_TYPE_new()) == NULL)
    return 0;

  if (!asn1_c2i_primitive(&atype->value.asn1_value, content, utype, it)) {
    ASN1_TYPE_free(atype);
    return 0;
  }
  atype->type = utype;

  /* Fix up value for ASN.1 NULL. */
  if (atype->type == V_ASN1_NULL)
    atype->value.ptr = NULL;

  *pval = (ASN1_VALUE *)atype;

  return 1;
}

static int
asn1_c2i(ASN1_VALUE **pval, CBS *content, int utype, const ASN1_ITEM *it)
{
  if (CBS_len(content) > INT_MAX)
    return 0;

  if (it->funcs != NULL) {
    const ASN1_PRIMITIVE_FUNCS *pf = it->funcs;
    char free_content = 0;

    if (pf->prim_c2i == NULL)
      return 0;

    return pf->prim_c2i(pval, CBS_data(content), CBS_len(content),
        utype, &free_content, it);
  }

  if (it->utype == V_ASN1_ANY)
    return asn1_c2i_any(pval, content, utype, it);

  return asn1_c2i_primitive(pval, content, utype, it);
}

/*
 * Decode ASN.1 content into a primitive type. There are three possible forms -
 * a SEQUENCE/SET/OTHER that is stored verbatim (including the ASN.1 tag and
 * length octets), constructed objects and non-constructed objects. In the
 * first two cases indefinite length is permitted, which we may need to handle.
 * When this function is called the *cbs should reference the start of the
 * ASN.1 object (i.e. the tag/length header), while *cbs_object should
 * reference the start of the object contents (i.e. after the tag/length
 * header. Additionally, the *cbs_object offset should be relative to the
 * ASN.1 object being parsed. On success the *cbs will point at the octet
 * after the object.
 */
static int
asn1_d2i_primitive_content(ASN1_VALUE **pval, CBS *cbs, CBS *cbs_object,
    int utype, int constructed, int indefinite, size_t length,
    const ASN1_ITEM *it)
{
  CBS cbs_content, cbs_initial;
  uint8_t *data = NULL;
  size_t data_len = 0;
  CBB cbb;
  int ret = 0;

  memset(&cbb, 0, sizeof(cbb));

  CBS_dup(cbs, &cbs_initial);
  CBS_init(&cbs_content, NULL, 0);

  /* XXX - check primitive vs constructed based on utype. */

  /* SEQUENCE and SET must be constructed. */
  if ((utype == V_ASN1_SEQUENCE || utype == V_ASN1_SET) && !constructed) {
    ASN1error(ASN1_R_TYPE_NOT_CONSTRUCTED);
    goto err;
  }

  /* SEQUENCE, SET and "OTHER" are left in encoded form. */
  if (utype == V_ASN1_SEQUENCE || utype == V_ASN1_SET ||
      utype == V_ASN1_OTHER) {
    if (!asn1_find_end(cbs_object, length, indefinite))
      goto err;
    if (!CBS_get_bytes(&cbs_initial, &cbs_content,
        CBS_offset(cbs_object)))
      goto err;
  } else if (constructed) {
    /*
     * Should really check the internal tags are correct but
     * some things may get this wrong. The relevant specs
     * say that constructed string types should be OCTET STRINGs
     * internally irrespective of the type. So instead just check
     * for UNIVERSAL class and ignore the tag.
     */
    if (!CBB_init(&cbb, 0))
      goto err;
    if (!asn1_collect(&cbb, cbs_object, indefinite, -1,
        V_ASN1_UNIVERSAL, 0))
      goto err;
    if (!CBB_finish(&cbb, &data, &data_len))
      goto err;

    CBS_init(&cbs_content, data, data_len);
  } else {
    if (!CBS_get_bytes(cbs_object, &cbs_content, length))
      goto err;
  }

  if (!asn1_c2i(pval, &cbs_content, utype, it))
    goto err;

  if (!CBS_skip(cbs, CBS_offset(cbs_object)))
    goto err;

  ret = 1;

 err:
  CBB_cleanup(&cbb);
  freezero(data, data_len);

  return ret;
}

static int
asn1_d2i_any(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
    int tag_number, int tag_class, int optional)
{
  int constructed, indefinite;
  uint8_t object_class;
  int object_type;
  CBS cbs_object;
  size_t length;

  CBS_init(&cbs_object, CBS_data(cbs), CBS_len(cbs));

  if (it->utype != V_ASN1_ANY)
    return 0;

  if (tag_number >= 0) {
    ASN1error(ASN1_R_ILLEGAL_TAGGED_ANY);
    return 0;
  }
  if (optional) {
    ASN1error(ASN1_R_ILLEGAL_OPTIONAL_ANY);
    return 0;
  }

  /* Determine type from ASN.1 tag. */
  if (asn1_check_tag(&cbs_object, &length, &object_type, &object_class,
      &indefinite, &constructed, -1, 0, 0) != 1) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    return 0;
  }
  if (object_class != V_ASN1_UNIVERSAL)
    object_type = V_ASN1_OTHER;

  return asn1_d2i_primitive_content(pval, cbs, &cbs_object, object_type,
      constructed, indefinite, length, it);
}

static int
asn1_d2i_mstring(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
    int tag_number, int tag_class, int optional)
{
  int constructed, indefinite;
  uint8_t object_class;
  int object_tag;
  CBS cbs_object;
  size_t length;

  CBS_init(&cbs_object, CBS_data(cbs), CBS_len(cbs));

  /*
   * It never makes sense for multi-strings to have implicit tagging, so
   * if tag_number != -1, then this looks like an error in the template.
   */
  if (tag_number != -1) {
    ASN1error(ASN1_R_BAD_TEMPLATE);
    return 0;
  }

  if (asn1_check_tag(&cbs_object, &length, &object_tag, &object_class,
      &indefinite, &constructed, -1, 0, 1) != 1) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    return 0;
  }

  /* Class must be UNIVERSAL. */
  if (object_class != V_ASN1_UNIVERSAL) {
    if (optional)
      return -1;
    ASN1error(ASN1_R_MSTRING_NOT_UNIVERSAL);
    return 0;
  }
  /* Check tag matches bit map. */
  if ((ASN1_tag2bit(object_tag) & it->utype) == 0) {
    if (optional)
      return -1;
    ASN1error(ASN1_R_MSTRING_WRONG_TAG);
    return 0;
  }

  return asn1_d2i_primitive_content(pval, cbs, &cbs_object,
      object_tag, constructed, indefinite, length, it);
}

static int
asn1_d2i_primitive(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
    int tag_number, int tag_class, int optional)
{
  CBS cbs_object;
  int constructed, indefinite;
  int utype = it->utype;
  size_t length;
  int ret;

  CBS_init(&cbs_object, CBS_data(cbs), CBS_len(cbs));

  if (it->itype == ASN1_ITYPE_MSTRING)
    return 0;

  if (it->utype == V_ASN1_ANY)
    return asn1_d2i_any(pval, cbs, it, tag_number, tag_class, optional);

  if (tag_number == -1) {
    tag_number = it->utype;
    tag_class = V_ASN1_UNIVERSAL;
  }

  ret = asn1_check_tag(&cbs_object, &length, NULL, NULL, &indefinite,
      &constructed, tag_number, tag_class, optional);
  if (ret == -1)
    return -1;
  if (ret != 1) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    return 0;
  }

  return asn1_d2i_primitive_content(pval, cbs, &cbs_object, utype,
      constructed, indefinite, length, it);
}

static int
asn1_item_d2i_choice(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
    int tag_number, int tag_class, int optional, int depth)
{
  const ASN1_TEMPLATE *at, *errat = NULL;
  const ASN1_AUX *aux;
  ASN1_aux_cb *asn1_cb = NULL;
  ASN1_VALUE *achoice = NULL;
  ASN1_VALUE **pchptr;
  int i, ret;

  if ((aux = it->funcs) != NULL)
    asn1_cb = aux->asn1_cb;

  if (it->itype != ASN1_ITYPE_CHOICE)
    goto err;

  /*
   * It never makes sense for CHOICE types to have implicit tagging, so
   * if tag_number != -1, then this looks like an error in the template.
   */
  if (tag_number != -1) {
    ASN1error(ASN1_R_BAD_TEMPLATE);
    goto err;
  }

  if (*pval != NULL) {
    ASN1_item_ex_free(pval, it);
    *pval = NULL;
  }

  if (!ASN1_item_ex_new(&achoice, it)) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    goto err;
  }

  if (asn1_cb != NULL && !asn1_cb(ASN1_OP_D2I_PRE, &achoice, it, NULL)) {
    ASN1error(ASN1_R_AUX_ERROR);
    goto err;
  }

  /* Try each possible CHOICE in turn. */
  for (i = 0; i < it->tcount; i++) {
    at = &it->templates[i];

    pchptr = asn1_get_field_ptr(&achoice, at);

    /* Mark field as OPTIONAL so its absence can be identified. */
    ret = asn1_template_d2i(pchptr, cbs, at, 1, depth);
    if (ret == -1)
      continue;
    if (ret != 1) {
      ASN1error(ERR_R_NESTED_ASN1_ERROR);
      errat = at;
      goto err;
    }

    /* We've successfully decoded an ASN.1 object. */
    asn1_set_choice_selector(&achoice, i, it);
    break;
  }

  /* Did we fall off the end without reading anything? */
  if (i == it->tcount) {
    if (optional) {
      ASN1_item_ex_free(&achoice, it);
      return -1;
    }
    ASN1error(ASN1_R_NO_MATCHING_CHOICE_TYPE);
    goto err;
  }

  if (asn1_cb != NULL && !asn1_cb(ASN1_OP_D2I_POST, &achoice, it, NULL)) {
    ASN1error(ASN1_R_AUX_ERROR);
    goto err;
  }

  *pval = achoice;
  achoice = NULL;

  return 1;

 err:
  ASN1_item_ex_free(&achoice, it);

  if (errat != NULL)
    ERR_asprintf_error_data("Field=%s, Type=%s", errat->field_name,
        it->sname);
  else
    ERR_asprintf_error_data("Type=%s", it->sname);

  return 0;
}

static int
asn1_item_d2i_sequence(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
    int tag_number, int tag_class, int optional, int depth)
{
  CBS cbs_seq, cbs_seq_content, cbs_object;
  int constructed, indefinite, optional_field;
  const ASN1_TEMPLATE *errat = NULL;
  const ASN1_TEMPLATE *seqat, *at;
  ASN1_aux_cb *asn1_cb = NULL;
  const ASN1_AUX *aux;
  ASN1_VALUE *aseq = NULL;
  ASN1_VALUE **pseqval;
  int eoc_needed, i;
  size_t length;
  int ret = 0;

  CBS_init(&cbs_seq, CBS_data(cbs), CBS_len(cbs));

  if ((aux = it->funcs) != NULL)
    asn1_cb = aux->asn1_cb;

  if (it->itype != ASN1_ITYPE_NDEF_SEQUENCE &&
      it->itype != ASN1_ITYPE_SEQUENCE)
    goto err;

  if (*pval != NULL) {
    ASN1_item_ex_free(pval, it);
    *pval = NULL;
  }

  /* If no IMPLICIT tagging use UNIVERSAL/SEQUENCE. */
  if (tag_number == -1) {
    tag_class = V_ASN1_UNIVERSAL;
    tag_number = V_ASN1_SEQUENCE;
  }

  /* Read ASN.1 SEQUENCE header. */
  ret = asn1_check_tag(&cbs_seq, &length, NULL, NULL, &indefinite,
      &constructed, tag_number, tag_class, optional);
  if (ret == -1)
    return -1;
  if (ret != 1) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    goto err;
  }

  if (!constructed) {
    ASN1error(ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
    goto err;
  }

  if (indefinite) {
    eoc_needed = 1;
    CBS_init(&cbs_seq_content, CBS_data(&cbs_seq), CBS_len(&cbs_seq));
  } else {
    eoc_needed = 0;
    if (!CBS_get_bytes(&cbs_seq, &cbs_seq_content, length))
      goto err;
  }

  if (!ASN1_item_ex_new(&aseq, it)) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    goto err;
  }

  if (asn1_cb != NULL && !asn1_cb(ASN1_OP_D2I_PRE, &aseq, it, NULL)) {
    ASN1error(ASN1_R_AUX_ERROR);
    goto err;
  }

  for (i = 0; i < it->tcount; i++) {
    at = &it->templates[i];

    if (asn1_check_eoc(&cbs_seq_content)) {
      if (!indefinite) {
        ASN1error(ASN1_R_UNEXPECTED_EOC);
        goto err;
      }
      eoc_needed = 0;
      break;
    }
    if (CBS_len(&cbs_seq_content) == 0)
      break;

    if ((seqat = asn1_do_adb(&aseq, at, 1)) == NULL)
      goto err;

    pseqval = asn1_get_field_ptr(&aseq, seqat);

    /*
     * This was originally implemented to "increase efficiency",
     * however it currently needs to remain since it papers over
     * the use of ASN.1 ANY with OPTIONAL in SEQUENCEs (which
     * asn1_d2i_primitive() currently rejects).
     */
    optional_field = (seqat->flags & ASN1_TFLG_OPTIONAL) != 0;
    if (i == it->tcount - 1)
      optional_field = 0;

    ret = asn1_template_d2i(pseqval, &cbs_seq_content,
        seqat, optional_field, depth);
    if (ret == -1) {
      /* Absent OPTIONAL component. */
      ASN1_template_free(pseqval, seqat);
      continue;
    }
    if (ret != 1) {
      errat = seqat;
      goto err;
    }
  }

  if (eoc_needed && !asn1_check_eoc(&cbs_seq_content)) {
    ASN1error(ASN1_R_MISSING_EOC);
    goto err;
  }

  if (indefinite) {
    if (!CBS_skip(&cbs_seq, CBS_offset(&cbs_seq_content)))
      goto err;
  } else if (CBS_len(&cbs_seq_content) != 0) {
    ASN1error(ASN1_R_SEQUENCE_LENGTH_MISMATCH);
    goto err;
  }

  /*
   * There is no more data in the ASN.1 SEQUENCE, however we may not have
   * populated all fields - check that any remaining are OPTIONAL.
   */
  for (; i < it->tcount; i++) {
    at = &it->templates[i];

    if ((seqat = asn1_do_adb(&aseq, at, 1)) == NULL)
      goto err;

    if ((seqat->flags & ASN1_TFLG_OPTIONAL) == 0) {
      ASN1error(ASN1_R_FIELD_MISSING);
      errat = seqat;
      goto err;
    }

    /* XXX - this is probably unnecessary with earlier free. */
    pseqval = asn1_get_field_ptr(&aseq, seqat);
    ASN1_template_free(pseqval, seqat);
  }

  if (!CBS_get_bytes(cbs, &cbs_object, CBS_offset(&cbs_seq)))
    goto err;

  if (!asn1_enc_save(&aseq, &cbs_object, it)) {
    ASN1error(ERR_R_MALLOC_FAILURE);
    goto err;
  }

  if (asn1_cb != NULL && !asn1_cb(ASN1_OP_D2I_POST, &aseq, it, NULL)) {
    ASN1error(ASN1_R_AUX_ERROR);
    goto err;
  }

  *pval = aseq;
  aseq = NULL;

  return 1;

 err:
  ASN1_item_ex_free(&aseq, it);

  if (errat != NULL)
    ERR_asprintf_error_data("Field=%s, Type=%s", errat->field_name,
        it->sname);
  else
    ERR_asprintf_error_data("Type=%s", it->sname);

  return 0;
}

static int
asn1_item_d2i_extern(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
    int tag_number, int tag_class, int optional)
{
  const ASN1_EXTERN_FUNCS *ef = it->funcs;
  const unsigned char *p = NULL;
  ASN1_TLC ctx = { 0 };
  int ret = 0;

  if (CBS_len(cbs) > LONG_MAX)
    return 0;

  p = CBS_data(cbs);

  if ((ret = ef->asn1_ex_d2i(pval, &p, (long)CBS_len(cbs), it,
      tag_number, tag_class, optional, &ctx)) == 1) {
    if (!CBS_skip(cbs, p - CBS_data(cbs)))
      goto err;
  }
  return ret;

 err:
  ASN1_item_ex_free(pval, it);

  ERR_asprintf_error_data("Type=%s", it->sname);

  return 0;
}

static int
asn1_item_d2i(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
    int tag_number, int tag_class, int optional, int depth)
{
  if (pval == NULL)
    return 0;

  if (++depth > ASN1_MAX_CONSTRUCTED_NEST) {
    ASN1error(ASN1_R_NESTED_TOO_DEEP);
    goto err;
  }

  switch (it->itype) {
  case ASN1_ITYPE_PRIMITIVE:
    if (it->templates != NULL) {
      /*
       * 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_number != -1 || optional) {
        ASN1error(ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
        goto err;
      }
      return asn1_template_d2i(pval, cbs, it->templates,
          optional, depth);
    }
    return asn1_d2i_primitive(pval, cbs, it, tag_number, tag_class,
        optional);

  case ASN1_ITYPE_MSTRING:
    return asn1_d2i_mstring(pval, cbs, it, tag_number, tag_class,
        optional);

  case ASN1_ITYPE_EXTERN:
    return asn1_item_d2i_extern(pval, cbs, it, tag_number,
        tag_class, optional);

  case ASN1_ITYPE_CHOICE:
    return asn1_item_d2i_choice(pval, cbs, it, tag_number,
        tag_class, optional, depth);

  case ASN1_ITYPE_NDEF_SEQUENCE:
  case ASN1_ITYPE_SEQUENCE:
    return asn1_item_d2i_sequence(pval, cbs, it, tag_number,
        tag_class, optional, depth);

  default:
    return 0;
  }

 err:
  ASN1_item_ex_free(pval, it);

  ERR_asprintf_error_data("Type=%s", it->sname);

  return 0;
}

static void
asn1_template_stack_of_free(STACK_OF(ASN1_VALUE) *avals, const ASN1_TEMPLATE *at) {
  ASN1_VALUE *aval;

  if (avals == NULL)
    return;

  while (sk_ASN1_VALUE_num(avals) > 0) {
    aval = sk_ASN1_VALUE_pop(avals);
    ASN1_item_ex_free(&aval, at->item);
  }
  sk_ASN1_VALUE_free(avals);
}

static int
asn1_template_stack_of_d2i(ASN1_VALUE **pval, CBS *cbs, const ASN1_TEMPLATE *at,
    int optional, int depth)
{
  CBS cbs_object, cbs_object_content;
  STACK_OF(ASN1_VALUE) *avals = NULL;
  ASN1_VALUE *aval = NULL;
  int tag_number, tag_class;
  int eoc_needed;
  int indefinite;
  size_t length;
  int ret;

  CBS_init(&cbs_object, CBS_data(cbs), CBS_len(cbs));

  if (pval == NULL)
    return 0;

  asn1_template_stack_of_free((STACK_OF(ASN1_VALUE) *)*pval, at);
  *pval = NULL;

  tag_number = at->tag;
  tag_class = at->flags & ASN1_TFLG_TAG_CLASS;

  /* Determine the inner tag value for SET OF or SEQUENCE OF. */
  if ((at->flags & ASN1_TFLG_IMPTAG) == 0) {
    tag_number = V_ASN1_SEQUENCE;
    tag_class = V_ASN1_UNIVERSAL;
    if ((at->flags & ASN1_TFLG_SET_OF) != 0)
      tag_number = V_ASN1_SET;
  }

  ret = asn1_check_tag(&cbs_object, &length, NULL, NULL, &indefinite,
      NULL, tag_number, tag_class, optional);
  if (ret == -1)
    return -1;
  if (ret != 1) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    return 0;
  }

  if (indefinite) {
    eoc_needed = 1;
    CBS_init(&cbs_object_content, CBS_data(&cbs_object),
        CBS_len(&cbs_object));
  } else {
    eoc_needed = 0;
    if (!CBS_get_bytes(&cbs_object, &cbs_object_content,
        length))
      goto err;
  }

  if ((avals = sk_ASN1_VALUE_new_null()) == NULL) {
    ASN1error(ERR_R_MALLOC_FAILURE);
    goto err;
  }

  /* Read as many items as possible. */
  while (CBS_len(&cbs_object_content) > 0) {
    if (asn1_check_eoc(&cbs_object_content)) {
      if (!eoc_needed) {
        ASN1error(ASN1_R_UNEXPECTED_EOC);
        goto err;
      }
      eoc_needed = 0;
      break;
    }
    if (!asn1_item_d2i(&aval, &cbs_object_content, at->item,
        -1, 0, 0, depth)) {
      ASN1error(ERR_R_NESTED_ASN1_ERROR);
      goto err;
    }
    if (!sk_ASN1_VALUE_push(avals, aval)) {
      ASN1error(ERR_R_MALLOC_FAILURE);
      goto err;
    }
    aval = NULL;
  }
  if (eoc_needed) {
    ASN1error(ASN1_R_MISSING_EOC);
    goto err;
  }

  if (indefinite) {
    if (!CBS_skip(&cbs_object, CBS_offset(&cbs_object_content)))
      goto err;
  }

  if (!CBS_skip(cbs, CBS_offset(&cbs_object)))
    goto err;

  *pval = (ASN1_VALUE *)avals;
  avals = NULL;

  return 1;

 err:
  asn1_template_stack_of_free(avals, at);
  ASN1_item_ex_free(&aval, at->item);

  return 0;
}

static int
asn1_template_noexp_d2i(ASN1_VALUE **pval, CBS *cbs, const ASN1_TEMPLATE *at,
    int optional, int depth)
{
  int tag_number, tag_class;
  int ret;

  if (pval == NULL)
    return 0;

  if ((at->flags & ASN1_TFLG_SK_MASK) != 0)
    return asn1_template_stack_of_d2i(pval, cbs, at, optional, depth);

  tag_number = -1;
  tag_class = V_ASN1_UNIVERSAL;

  /* See if we need to use IMPLICIT tagging. */
  if ((at->flags & ASN1_TFLG_IMPTAG) != 0) {
    tag_number = at->tag;
    tag_class = at->flags & ASN1_TFLG_TAG_CLASS;
  }

  ret = asn1_item_d2i(pval, cbs, at->item, tag_number, tag_class,
      optional, depth);
  if (ret == -1)
    return -1;
  if (ret != 1) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    goto err;
  }

  return 1;

 err:
  /* XXX - The called function should have freed already. */
  ASN1_template_free(pval, at);
  return 0;
}

static int
asn1_template_d2i(ASN1_VALUE **pval, CBS *cbs, const ASN1_TEMPLATE *at,
    int optional, int depth)
{
  CBS cbs_exp, cbs_exp_content;
  int constructed, indefinite;
  size_t length;
  int ret;

  if (pval == NULL)
    return 0;

  /* Check if EXPLICIT tag is expected. */
  if ((at->flags & ASN1_TFLG_EXPTAG) == 0)
    return asn1_template_noexp_d2i(pval, cbs, at, optional, depth);

  CBS_init(&cbs_exp, CBS_data(cbs), CBS_len(cbs));

  /* Read ASN.1 header for EXPLICIT tagged object. */
  ret = asn1_check_tag(&cbs_exp, &length, NULL, NULL, &indefinite,
      &constructed, at->tag, at->flags & ASN1_TFLG_TAG_CLASS, optional);
  if (ret == -1)
    return -1;
  if (ret != 1) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    return 0;
  }

  if (!constructed) {
    ASN1error(ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
    return 0;
  }

  if (indefinite) {
    CBS_init(&cbs_exp_content, CBS_data(&cbs_exp), CBS_len(&cbs_exp));
  } else {
    if (!CBS_get_bytes(&cbs_exp, &cbs_exp_content, length))
      goto err;
  }

  if ((ret = asn1_template_noexp_d2i(pval, &cbs_exp_content, at, 0,
      depth)) != 1) {
    ASN1error(ERR_R_NESTED_ASN1_ERROR);
    return 0;
  }

  if (indefinite) {
    if (!asn1_check_eoc(&cbs_exp_content)) {
      ASN1error(ASN1_R_MISSING_EOC);
      goto err;
    }
    if (!CBS_skip(&cbs_exp, CBS_offset(&cbs_exp_content)))
      goto err;
  } else if (CBS_len(&cbs_exp_content) != 0) {
    ASN1error(ASN1_R_SEQUENCE_LENGTH_MISMATCH);
    goto err;
  }

  if (!CBS_skip(cbs, CBS_offset(&cbs_exp)))
    goto err;

  return 1;

 err:
  ASN1_template_free(pval, at);
  return 0;
}

ASN1_VALUE *
ASN1_item_d2i(ASN1_VALUE **pval, const unsigned char **in, long inlen,
    const ASN1_ITEM *it)
{
  ASN1_VALUE *ptmpval = NULL;

  if (pval == NULL)
    pval = &ptmpval;
  if (ASN1_item_ex_d2i(pval, in, inlen, it, -1, 0, 0, NULL) <= 0)
    return NULL;

  return *pval;
}

int
ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long inlen,
    const ASN1_ITEM *it, int tag_number, int tag_class, char optional,
    ASN1_TLC *ctx)
{
  CBS cbs;
  int ret;

  if (inlen < 0)
    return 0;

  CBS_init(&cbs, *in, inlen);
  if ((ret = asn1_item_d2i(pval, &cbs, it, tag_number, tag_class,
      (int)optional, 0)) == 1)
    *in = CBS_data(&cbs);

  return ret;
}

int
ASN1_template_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
    const ASN1_TEMPLATE *at)
{
  CBS cbs;
  int ret;

  if (len < 0)
    return 0;

  CBS_init(&cbs, *in, len);
  if ((ret = asn1_template_d2i(pval, &cbs, at, 0, 0)) == 1)
    *in = CBS_data(&cbs);

  return ret;
}

Coverage Report

Created: 2022-08-24 06:31