static int asn1_ex_c2i()

in crypto/asn1/tasn_dec.c [788:935]

• 133 lines of code
• 48 McCabe index (conditional complexity)

static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, long 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) {
          goto err;
        }
        *pval = (ASN1_VALUE *)stmp;
      } else {
        stmp = (ASN1_STRING *)*pval;
        stmp->type = utype;
      }
      if (!ASN1_STRING_set(stmp, cont, len)) {
        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;
}