// Copyright 2017 The Chromium Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef BSSL_PKI_GENERAL_NAMES_H_
#define BSSL_PKI_GENERAL_NAMES_H_

#include <memory>
#include <string_view>
#include <vector>

#include <openssl/base.h>


#include "cert_error_id.h"

BSSL_NAMESPACE_BEGIN

class CertErrors;

OPENSSL_EXPORT extern const CertErrorId kFailedParsingGeneralName;

namespace der {
class Input;
}  // namespace der

// Bitfield values for the GeneralName types defined in RFC 5280. The ordering
// and exact values are not important, but match the order from the RFC for
// convenience.
enum GeneralNameTypes {
  GENERAL_NAME_NONE = 0,
  GENERAL_NAME_OTHER_NAME = 1 << 0,
  GENERAL_NAME_RFC822_NAME = 1 << 1,
  GENERAL_NAME_DNS_NAME = 1 << 2,
  GENERAL_NAME_X400_ADDRESS = 1 << 3,
  GENERAL_NAME_DIRECTORY_NAME = 1 << 4,
  GENERAL_NAME_EDI_PARTY_NAME = 1 << 5,
  GENERAL_NAME_UNIFORM_RESOURCE_IDENTIFIER = 1 << 6,
  GENERAL_NAME_IP_ADDRESS = 1 << 7,
  GENERAL_NAME_REGISTERED_ID = 1 << 8,
  GENERAL_NAME_ALL_TYPES = (1 << 9) - 1,
};

// Represents a GeneralNames structure. When processing GeneralNames, it is
// often necessary to know which types of names were present, and to check
// all the names of a certain type. Therefore, a bitfield of all the name
// types is kept, and the names are split into members for each type.
struct OPENSSL_EXPORT GeneralNames {
  // Controls parsing of iPAddress names in ParseGeneralName.
  // IP_ADDRESS_ONLY parses the iPAddress names as a 4 or 16 byte IP address.
  // IP_ADDRESS_AND_NETMASK parses the iPAddress names as 8 or 32 bytes
  // containing an IP address followed by a netmask.
  enum ParseGeneralNameIPAddressType {
    IP_ADDRESS_ONLY,
    IP_ADDRESS_AND_NETMASK,
  };

  GeneralNames();
  ~GeneralNames();

  // Create a GeneralNames object representing the DER-encoded
  // |general_names_tlv|. The returned object may reference data from
  // |general_names_tlv|, so is only valid as long as |general_names_tlv| is.
  // Returns nullptr on failure, and may fill |errors| with
  // additional information. |errors| must be non-null.
  static std::unique_ptr<GeneralNames> Create(der::Input general_names_tlv,
                                              CertErrors *errors);

  // As above, but takes the GeneralNames sequence value, without the tag and
  // length.
  static std::unique_ptr<GeneralNames> CreateFromValue(
      der::Input general_names_value, CertErrors *errors);

  // DER-encoded OtherName values.
  std::vector<der::Input> other_names;

  // ASCII rfc822names.
  std::vector<std::string_view> rfc822_names;

  // ASCII hostnames.
  std::vector<std::string_view> dns_names;

  // DER-encoded ORAddress values.
  std::vector<der::Input> x400_addresses;

  // DER-encoded Name values (not including the Sequence tag).
  std::vector<der::Input> directory_names;

  // DER-encoded EDIPartyName values.
  std::vector<der::Input> edi_party_names;

  // ASCII URIs.
  std::vector<std::string_view> uniform_resource_identifiers;

  // iPAddresses as sequences of octets in network byte order. This will be
  // populated if the GeneralNames represents a Subject Alternative Name. Each
  // address is guaranteed to be either 4 bytes (IPv4) or 16 bytes (IPv6) long.
  std::vector<der::Input> ip_addresses;

  // iPAddress ranges, as <IP, mask> pairs. This will be populated
  // if the GeneralNames represents a Name Constraints. Each address is
  // guaranteed to be either 4 bytes (IPv4) or 16 bytes (IPv6) long. The mask
  // half is guaranteed to be the same size, and consist of some number of 1
  // bits, followed by some number of 0 bits.
  //
  // WARNING: It is not guaranteed that the masked portions of the address are
  // zero.
  //
  // TODO(davidben): Should addresses with non-zero masked portions be rejected?
  std::vector<std::pair<der::Input, der::Input>> ip_address_ranges;

  // DER-encoded OBJECT IDENTIFIERs.
  std::vector<der::Input> registered_ids;

  // Which name types were present, as a bitfield of GeneralNameTypes.
  int present_name_types = GENERAL_NAME_NONE;
};

// Parses a GeneralName value and adds it to |subtrees|.
// |ip_address_type| specifies how to parse iPAddress names.
// Returns false on failure, and may fill |errors| with additional information.
// |errors| must be non-null.
// TODO(mattm): should this be a method on GeneralNames?
[[nodiscard]] OPENSSL_EXPORT bool ParseGeneralName(
    der::Input input,
    GeneralNames::ParseGeneralNameIPAddressType ip_address_type,
    GeneralNames *subtrees, CertErrors *errors);

BSSL_NAMESPACE_END

#endif  // BSSL_PKI_GENERAL_NAMES_H_