/*

* ASN.1 Internals

* (C) 1999-2007,2018 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#ifndef BOTAN_ASN1_H_

#define BOTAN_ASN1_H_

#include <botan/secmem.h>

#include <botan/exceptn.h>

namespace Botan {

class BER_Decoder;

class DER_Encoder;

/**

* ASN.1 Type and Class Tags

* This will become an enum class in a future major release

*/

enum ASN1_Tag : uint32_t {

   UNIVERSAL        = 0x00,

   APPLICATION      = 0x40,

   CONTEXT_SPECIFIC = 0x80,

   CONSTRUCTED      = 0x20,

   PRIVATE          = CONSTRUCTED | CONTEXT_SPECIFIC,

   EOC              = 0x00,

   BOOLEAN          = 0x01,

   INTEGER          = 0x02,

   BIT_STRING       = 0x03,

   OCTET_STRING     = 0x04,

   NULL_TAG         = 0x05,

   OBJECT_ID        = 0x06,

   ENUMERATED       = 0x0A,

   SEQUENCE         = 0x10,

   SET              = 0x11,

   UTF8_STRING      = 0x0C,

   NUMERIC_STRING   = 0x12,

   PRINTABLE_STRING = 0x13,

   T61_STRING       = 0x14,

   IA5_STRING       = 0x16,

   VISIBLE_STRING   = 0x1A,

   UNIVERSAL_STRING = 0x1C,

   BMP_STRING       = 0x1E,

   UTC_TIME                = 0x17,

   GENERALIZED_TIME        = 0x18,

   UTC_OR_GENERALIZED_TIME = 0x19,

   NO_OBJECT        = 0xFF00,

   DIRECTORY_STRING = 0xFF01

};

std::string BOTAN_UNSTABLE_API asn1_tag_to_string(ASN1_Tag type);

std::string BOTAN_UNSTABLE_API asn1_class_to_string(ASN1_Tag type);

/**

* Basic ASN.1 Object Interface

*/

class BOTAN_PUBLIC_API(2,0) ASN1_Object

   {

   public:

      /**

      * Encode whatever this object is into to

      * @param to the DER_Encoder that will be written to

      */

      virtual void encode_into(DER_Encoder& to) const = 0;

      /**

      * Decode whatever this object is from from

      * @param from the BER_Decoder that will be read from

      */

      virtual void decode_from(BER_Decoder& from) = 0;

      /**

      * Return the encoding of this object. This is a convenience

      * method when just one object needs to be serialized. Use

      * DER_Encoder for complicated encodings.

      */

      std::vector<uint8_t> BER_encode() const;

      ASN1_Object() = default;

      ASN1_Object(const ASN1_Object&) = default;

      ASN1_Object & operator=(const ASN1_Object&) = default;

      virtual ~ASN1_Object() = default;

   };

/**

* BER Encoded Object

*/

class BOTAN_PUBLIC_API(2,0) BER_Object final

   {

   public:

      BER_Object() : type_tag(NO_OBJECT), class_tag(UNIVERSAL) {}

      BER_Object(const BER_Object& other) = default;

      BER_Object& operator=(const BER_Object& other) = default;

      BER_Object(BER_Object&& other) = default;

      BER_Object& operator=(BER_Object&& other) = default;

      bool is_set() const { return type_tag != NO_OBJECT; }

      ASN1_Tag tagging() const { return ASN1_Tag(type() | get_class()); }

      ASN1_Tag type() const { return type_tag; }

      ASN1_Tag get_class() const { return class_tag; }

      const uint8_t* bits() const { return value.data(); }

      size_t length() const { return value.size(); }

      void assert_is_a(ASN1_Tag type_tag, ASN1_Tag class_tag,

                       const std::string& descr = "object") const;

      bool is_a(ASN1_Tag type_tag, ASN1_Tag class_tag) const;

      bool is_a(int type_tag, ASN1_Tag class_tag) const;

   BOTAN_DEPRECATED_PUBLIC_MEMBER_VARIABLES:

      /*

      * The following member variables are public for historical reasons, but

      * will be made private in a future major release. Use the accessor

      * functions above.

      */

      ASN1_Tag type_tag, class_tag;

      secure_vector<uint8_t> value;

   private:

      friend class BER_Decoder;

      void set_tagging(ASN1_Tag type_tag, ASN1_Tag class_tag);

      uint8_t* mutable_bits(size_t length)

         {

         value.resize(length);

         return value.data();

         }

   };

/*

* ASN.1 Utility Functions

*/

class DataSource;

namespace ASN1 {

std::vector<uint8_t> put_in_sequence(const std::vector<uint8_t>& val);

std::vector<uint8_t> put_in_sequence(const uint8_t bits[], size_t len);

std::string to_string(const BER_Object& obj);

/**

* Heuristics tests; is this object possibly BER?

* @param src a data source that will be peeked at but not modified

*/

bool maybe_BER(DataSource& src);

}

/**

* General BER Decoding Error Exception

*/

class BOTAN_PUBLIC_API(2,0) BER_Decoding_Error : public Decoding_Error

   {

   public:

      explicit BER_Decoding_Error(const std::string&);

   };

/**

* Exception For Incorrect BER Taggings

*/

class BOTAN_PUBLIC_API(2,0) BER_Bad_Tag final : public BER_Decoding_Error

   {

   public:

      BER_Bad_Tag(const std::string& msg, ASN1_Tag tag);

      BER_Bad_Tag(const std::string& msg, ASN1_Tag tag1, ASN1_Tag tag2);

   };

}

#endif