Botan::BER_Decoder Class Reference

#include <ber_dec.h>

Public Member Functions
	BER_Decoder (const BER_Decoder &)
	BER_Decoder (const byte[], size_t)
	BER_Decoder (const MemoryRegion< byte > &)
	BER_Decoder (DataSource &)
BER_Decoder &	decode (bool &)
BER_Decoder &	decode (bool &, ASN1_Tag, ASN1_Tag=CONTEXT_SPECIFIC)
BER_Decoder &	decode (class ASN1_Object &)
BER_Decoder &	decode (class BigInt &)
BER_Decoder &	decode (class BigInt &, ASN1_Tag, ASN1_Tag=CONTEXT_SPECIFIC)
BER_Decoder &	decode (MemoryRegion< byte > &, ASN1_Tag)
BER_Decoder &	decode (MemoryRegion< byte > &, ASN1_Tag, ASN1_Tag, ASN1_Tag=CONTEXT_SPECIFIC)
BER_Decoder &	decode (size_t &)
BER_Decoder &	decode (size_t &, ASN1_Tag, ASN1_Tag=CONTEXT_SPECIFIC)
template<typename T>
BER_Decoder &	decode_and_check (const T &expected, const std::string &error_msg)
template<typename T>
BER_Decoder &	decode_list (std::vector< T > &out, bool clear_out=true)
BER_Decoder &	decode_null ()
BER_Decoder &	decode_octet_string_bigint (class BigInt &)
template<typename T>
BER_Decoder &	decode_optional (T &out, ASN1_Tag type_tag, ASN1_Tag class_tag, const T &default_value=T())
BER_Decoder &	decode_optional_string (MemoryRegion< byte > &, ASN1_Tag, u16bit)
BER_Decoder &	discard_remaining ()
BER_Decoder &	end_cons ()
BER_Object	get_next_object ()
bool	more_items () const
void	push_back (const BER_Object &)
BER_Decoder &	raw_bytes (MemoryRegion< byte > &)
BER_Decoder	start_cons (ASN1_Tag, ASN1_Tag=UNIVERSAL)
BER_Decoder &	verify_end ()
	~BER_Decoder ()

Detailed Description

BER Decoding Object

Definition at line 19 of file ber_dec.h.

Constructor & Destructor Documentation

BER_Decoder() [1/4]

Botan::BER_Decoder::BER_Decoder

(

DataSource &

src

)

Definition at line 264 of file ber_dec.cpp.

   {
   source = &src;
   owns = false;
   pushed.type_tag = pushed.class_tag = NO_OBJECT;
   parent = 0;
   }

References Botan::NO_OBJECT.

Referenced by BER_Decoder(), decode(), decode(), decode(), decode(), decode(), decode(), decode(), decode(), decode(), decode_and_check(), Botan::EAC1_1_gen_CVC< Derived >::decode_info(), decode_list(), decode_null(), decode_octet_string_bigint(), decode_optional(), decode_optional_string(), discard_remaining(), Botan::DL_Scheme_PrivateKey::DL_Scheme_PrivateKey(), Botan::DL_Scheme_PublicKey::DL_Scheme_PublicKey(), Botan::EC_Group::EC_Group(), Botan::EC_PrivateKey::EC_PrivateKey(), Botan::ECDSA_Signature::ECDSA_Signature(), end_cons(), Botan::IF_Scheme_PrivateKey::IF_Scheme_PrivateKey(), Botan::IF_Scheme_PublicKey::IF_Scheme_PublicKey(), Botan::X509::load_key(), raw_bytes(), start_cons(), and verify_end().

BER_Decoder() [2/4]

Botan::BER_Decoder::BER_Decoder	(	const byte	data[],
		size_t	length )

Definition at line 275 of file ber_dec.cpp.

   {
   source = new DataSource_Memory(data, length);
   owns = true;
   pushed.type_tag = pushed.class_tag = NO_OBJECT;
   parent = 0;
   }

References Botan::DataSource_Memory::DataSource_Memory(), and Botan::NO_OBJECT.

BER_Decoder() [3/4]

Botan::BER_Decoder::BER_Decoder

(

const MemoryRegion< byte > &

data

)

Definition at line 286 of file ber_dec.cpp.

   {
   source = new DataSource_Memory(data);
   owns = true;
   pushed.type_tag = pushed.class_tag = NO_OBJECT;
   parent = 0;
   }

References Botan::DataSource_Memory::DataSource_Memory(), and Botan::NO_OBJECT.

BER_Decoder() [4/4]

Botan::BER_Decoder::BER_Decoder

(

const BER_Decoder &

other

)

Definition at line 297 of file ber_dec.cpp.

   {
   source = other.source;
   owns = false;
   if(other.owns)
      {
      other.owns = false;
      owns = true;
      }
   pushed.type_tag = pushed.class_tag = NO_OBJECT;
   parent = other.parent;
   }

References BER_Decoder(), and Botan::NO_OBJECT.

~BER_Decoder()

Botan::BER_Decoder::~BER_Decoder

(

)

Definition at line 313 of file ber_dec.cpp.

   {
   if(owns)
      delete source;
   source = 0;
   }

Member Function Documentation

decode() [1/9]

BER_Decoder & Botan::BER_Decoder::decode

(

bool &

out

)

Definition at line 344 of file ber_dec.cpp.

   {
   return decode(out, BOOLEAN, UNIVERSAL);
   }

References BER_Decoder(), Botan::BOOLEAN, decode(), and Botan::UNIVERSAL.

Referenced by Botan::DL_Group::BER_decode(), Botan::PK_Verifier::check_signature(), decode(), decode(), decode(), decode(), decode(), decode_and_check(), Botan::AlgorithmIdentifier::decode_from(), Botan::AlternativeName::decode_from(), Botan::Attribute::decode_from(), Botan::CRL_Entry::decode_from(), Botan::Extensions::decode_from(), Botan::X509_DN::decode_from(), decode_list(), decode_octet_string_bigint(), decode_optional(), and decode_optional_string().

decode() [2/9]

BER_Decoder & Botan::BER_Decoder::decode	(	bool &	out,
		ASN1_Tag	type_tag,
		ASN1_Tag	class_tag = CONTEXT_SPECIFIC )

Definition at line 376 of file ber_dec.cpp.

   {
   BER_Object obj = get_next_object();
   obj.assert_is_a(type_tag, class_tag);
 
   if(obj.value.size() != 1)
      throw BER_Decoding_Error("BER boolean value had invalid size");
 
   out = (obj.value[0]) ? true : false;
   return (*this);
   }

References Botan::BER_Object::assert_is_a(), BER_Decoder(), Botan::BER_Decoding_Error::BER_Decoding_Error(), get_next_object(), Botan::MemoryRegion< T >::size(), and Botan::BER_Object::value.

decode() [3/9]

BER_Decoder & Botan::BER_Decoder::decode

(

class ASN1_Object &

obj

)

Definition at line 323 of file ber_dec.cpp.

   {
   obj.decode_from(*this);
   return (*this);
   }

References BER_Decoder(), and Botan::ASN1_Object::decode_from().

decode() [4/9]

BER_Decoder & Botan::BER_Decoder::decode

(

class BigInt &

out

)

Definition at line 360 of file ber_dec.cpp.

   {
   return decode(out, INTEGER, UNIVERSAL);
   }

References BER_Decoder(), decode(), Botan::INTEGER, and Botan::UNIVERSAL.

decode() [5/9]

BER_Decoder & Botan::BER_Decoder::decode	(	class BigInt &	out,
		ASN1_Tag	type_tag,
		ASN1_Tag	class_tag = CONTEXT_SPECIFIC )

Definition at line 411 of file ber_dec.cpp.

   {
   BER_Object obj = get_next_object();
   obj.assert_is_a(type_tag, class_tag);
 
   if(obj.value.empty())
      out = 0;
   else
      {
      const bool negative = (obj.value[0] & 0x80) ? true : false;
 
      if(negative)
         {
         for(size_t i = obj.value.size(); i > 0; --i)
            if(obj.value[i-1]--)
               break;
         for(size_t i = 0; i != obj.value.size(); ++i)
            obj.value[i] = ~obj.value[i];
         }
 
      out = BigInt(&obj.value[0], obj.value.size());
 
      if(negative)
         out.flip_sign();
      }
 
   return (*this);
   }

References Botan::BER_Object::assert_is_a(), BER_Decoder(), Botan::BigInt::BigInt(), Botan::MemoryRegion< T >::empty(), Botan::BigInt::flip_sign(), get_next_object(), Botan::MemoryRegion< T >::size(), and Botan::BER_Object::value.

decode() [6/9]

BER_Decoder & Botan::BER_Decoder::decode	(	MemoryRegion< byte > &	out,
		ASN1_Tag	real_type )

Definition at line 444 of file ber_dec.cpp.

   {
   return decode(out, real_type, real_type, UNIVERSAL);
   }

References BER_Decoder(), decode(), and Botan::UNIVERSAL.

decode() [7/9]

BER_Decoder & Botan::BER_Decoder::decode	(	MemoryRegion< byte > &	buffer,
		ASN1_Tag	real_type,
		ASN1_Tag	type_tag,
		ASN1_Tag	class_tag = CONTEXT_SPECIFIC )

Definition at line 452 of file ber_dec.cpp.

   {
   if(real_type != OCTET_STRING && real_type != BIT_STRING)
      throw BER_Bad_Tag("Bad tag for {BIT,OCTET} STRING", real_type);
 
   BER_Object obj = get_next_object();
   obj.assert_is_a(type_tag, class_tag);
 
   if(real_type == OCTET_STRING)
      buffer = obj.value;
   else
      {
      if(obj.value.empty())
         throw BER_Decoding_Error("Invalid BIT STRING");
      if(obj.value[0] >= 8)
         throw BER_Decoding_Error("Bad number of unused bits in BIT STRING");
 
      buffer.resize(obj.value.size() - 1);
      copy_mem(&buffer[0], &obj.value[1], obj.value.size() - 1);
      }
   return (*this);
   }

References Botan::BER_Object::assert_is_a(), Botan::BER_Bad_Tag::BER_Bad_Tag(), BER_Decoder(), Botan::BER_Decoding_Error::BER_Decoding_Error(), Botan::BIT_STRING, Botan::copy_mem(), Botan::MemoryRegion< T >::empty(), get_next_object(), Botan::OCTET_STRING, Botan::MemoryRegion< T >::resize(), Botan::MemoryRegion< T >::size(), and Botan::BER_Object::value.

decode() [8/9]

BER_Decoder & Botan::BER_Decoder::decode

(

size_t &

out

)

Definition at line 352 of file ber_dec.cpp.

   {
   return decode(out, INTEGER, UNIVERSAL);
   }

References BER_Decoder(), decode(), Botan::INTEGER, and Botan::UNIVERSAL.

decode() [9/9]

BER_Decoder & Botan::BER_Decoder::decode	(	size_t &	out,
		ASN1_Tag	type_tag,
		ASN1_Tag	class_tag = CONTEXT_SPECIFIC )

Definition at line 392 of file ber_dec.cpp.

   {
   BigInt integer;
   decode(integer, type_tag, class_tag);
 
   if(integer.bits() > 32)
      throw BER_Decoding_Error("Decoded integer value larger than expected");
 
   out = 0;
   for(size_t i = 0; i != 4; ++i)
      out = (out << 8) | integer.byte_at(3-i);
 
   return (*this);
   }

References BER_Decoder(), Botan::BER_Decoding_Error::BER_Decoding_Error(), Botan::BigInt::bits(), Botan::BigInt::byte_at(), and decode().

decode_and_check()

template<typename T>

BER_Decoder & Botan::BER_Decoder::decode_and_check ( const T & expected, const std::string & error_msg )

inline

Definition at line 62 of file ber_dec.h.

         {
         T actual;
         decode(actual);
 
         if(actual != expected)
            throw Decoding_Error(error_msg);
 
         return (*this);
         }

References BER_Decoder(), and decode().

decode_list()

template<typename T>

BER_Decoder & Botan::BER_Decoder::decode_list	(	std::vector< T > &	out,
		bool	clear_out = true )

Definition at line 125 of file ber_dec.h.

   {
   if(clear_it)
      vec.clear();
 
   while(more_items())
      {
      T value;
      decode(value);
      vec.push_back(value);
      }
   return (*this);
   }

References BER_Decoder(), decode(), and more_items().

decode_null()

BER_Decoder & Botan::BER_Decoder::decode_null

(

)

Definition at line 332 of file ber_dec.cpp.

   {
   BER_Object obj = get_next_object();
   obj.assert_is_a(NULL_TAG, UNIVERSAL);
   if(obj.value.size())
      throw BER_Decoding_Error("NULL object had nonzero size");
   return (*this);
   }

References Botan::BER_Object::assert_is_a(), BER_Decoder(), Botan::BER_Decoding_Error::BER_Decoding_Error(), get_next_object(), Botan::NULL_TAG, Botan::MemoryRegion< T >::size(), Botan::UNIVERSAL, and Botan::BER_Object::value.

decode_octet_string_bigint()

BER_Decoder & Botan::BER_Decoder::decode_octet_string_bigint

(

class BigInt &

out

)

Definition at line 365 of file ber_dec.cpp.

   {
   SecureVector<byte> out_vec;
   decode(out_vec, OCTET_STRING);
   out = BigInt::decode(&out_vec[0], out_vec.size());
   return (*this);
   }

References BER_Decoder(), decode(), Botan::BigInt::decode(), Botan::OCTET_STRING, and Botan::MemoryRegion< T >::size().

decode_optional()

template<typename T>

BER_Decoder & Botan::BER_Decoder::decode_optional	(	T &	out,
		ASN1_Tag	type_tag,
		ASN1_Tag	class_tag,
		const T &	default_value = T() )

Definition at line 95 of file ber_dec.h.

   {
   BER_Object obj = get_next_object();
 
   if(obj.type_tag == type_tag && obj.class_tag == class_tag)
      {
      if(class_tag & CONSTRUCTED)
         BER_Decoder(obj.value).decode(out).verify_end();
      else
         {
         push_back(obj);
         decode(out, type_tag, class_tag);
         }
      }
   else
      {
      out = default_value;
      push_back(obj);
      }
 
   return (*this);
   }

References BER_Decoder(), Botan::BER_Object::class_tag, Botan::CONSTRUCTED, decode(), get_next_object(), push_back(), Botan::BER_Object::type_tag, and Botan::BER_Object::value.

Referenced by Botan::Extensions::decode_from().

decode_optional_string()

BER_Decoder & Botan::BER_Decoder::decode_optional_string	(	MemoryRegion< byte > &	out,
		ASN1_Tag	real_type,
		u16bit	type_no )

Definition at line 480 of file ber_dec.cpp.

   {
   BER_Object obj = get_next_object();
 
   ASN1_Tag type_tag = static_cast<ASN1_Tag>(type_no);
 
   out.clear();
   push_back(obj);
 
   if(obj.type_tag == type_tag && obj.class_tag == CONTEXT_SPECIFIC)
      decode(out, real_type, type_tag, CONTEXT_SPECIFIC);
 
   return (*this);
   }

References BER_Decoder(), Botan::BER_Object::class_tag, Botan::MemoryRegion< T >::clear(), Botan::CONTEXT_SPECIFIC, decode(), get_next_object(), push_back(), and Botan::BER_Object::type_tag.

discard_remaining()

BER_Decoder & Botan::BER_Decoder::discard_remaining

(

)

Definition at line 185 of file ber_dec.cpp.

   {
   byte buf;
   while(source->read_byte(buf))
      ;
   return (*this);
   }

References BER_Decoder().

Referenced by Botan::DL_Group::BER_decode().

end_cons()

BER_Decoder & Botan::BER_Decoder::end_cons

(

)

Definition at line 252 of file ber_dec.cpp.

   {
   if(!parent)
      throw Invalid_State("BER_Decoder::end_cons called with NULL parent");
   if(!source->end_of_data())
      throw Decoding_Error("BER_Decoder::end_cons called with data left");
   return (*parent);
   }

References BER_Decoder(), Botan::Decoding_Error::Decoding_Error(), and Botan::Invalid_State::Invalid_State().

Referenced by Botan::AlgorithmIdentifier::decode_from(), Botan::Attribute::decode_from(), Botan::CRL_Entry::decode_from(), Botan::Extensions::decode_from(), and Botan::X509_DN::decode_from().

get_next_object()

BER_Object Botan::BER_Decoder::get_next_object

(

)

Definition at line 196 of file ber_dec.cpp.

   {
   BER_Object next;
 
   if(pushed.type_tag != NO_OBJECT)
      {
      next = pushed;
      pushed.class_tag = pushed.type_tag = NO_OBJECT;
      return next;
      }
 
   decode_tag(source, next.type_tag, next.class_tag);
   if(next.type_tag == NO_OBJECT)
      return next;
 
   const size_t length = decode_length(source);
   if(!source->check_available(length))
      throw BER_Decoding_Error("Value truncated");
 
   next.value.resize(length);
   if(source->read(&next.value[0], length) != length)
      throw BER_Decoding_Error("Value truncated");
 
   if(next.type_tag == EOC && next.class_tag == UNIVERSAL)
      return get_next_object();
 
   return next;
   }

References Botan::BER_Decoding_Error::BER_Decoding_Error(), Botan::BER_Object::class_tag, Botan::EOC, get_next_object(), Botan::NO_OBJECT, Botan::MemoryRegion< T >::resize(), Botan::BER_Object::type_tag, Botan::UNIVERSAL, and Botan::BER_Object::value.

Referenced by Botan::BER::decode(), decode(), decode(), decode(), Botan::AlternativeName::decode_from(), Botan::ASN1_EAC_String::decode_from(), Botan::ASN1_String::decode_from(), Botan::EAC_Time::decode_from(), Botan::OID::decode_from(), Botan::X509_Time::decode_from(), decode_null(), decode_optional(), decode_optional_string(), Botan::EC_Group::EC_Group(), get_next_object(), and start_cons().

more_items()

bool Botan::BER_Decoder::more_items

(

)

const

Definition at line 153 of file ber_dec.cpp.

   {
   if(source->end_of_data() && (pushed.type_tag == NO_OBJECT))
      return false;
   return true;
   }

References Botan::NO_OBJECT.

Referenced by Botan::PK_Verifier::check_signature(), Botan::AlternativeName::decode_from(), Botan::CRL_Entry::decode_from(), Botan::Extensions::decode_from(), Botan::X509_DN::decode_from(), and decode_list().

push_back()

void Botan::BER_Decoder::push_back

(

const BER_Object &

obj

)

Definition at line 228 of file ber_dec.cpp.

   {
   if(pushed.type_tag != NO_OBJECT)
      throw Invalid_State("BER_Decoder: Only one push back is allowed");
   pushed = obj;
   }

References Botan::Invalid_State::Invalid_State(), and Botan::NO_OBJECT.

Referenced by decode_optional(), and decode_optional_string().

raw_bytes()

BER_Decoder & Botan::BER_Decoder::raw_bytes

(

MemoryRegion< byte > &

out

)

Definition at line 173 of file ber_dec.cpp.

   {
   out.clear();
   byte buf;
   while(source->read_byte(buf))
      out.push_back(buf);
   return (*this);
   }

References BER_Decoder(), Botan::MemoryRegion< T >::clear(), and Botan::MemoryRegion< T >::push_back().

Referenced by Botan::AlgorithmIdentifier::decode_from(), Botan::Attribute::decode_from(), and Botan::X509_DN::decode_from().

start_cons()

BER_Decoder Botan::BER_Decoder::start_cons	(	ASN1_Tag	type_tag,
		ASN1_Tag	class_tag = UNIVERSAL )

Definition at line 238 of file ber_dec.cpp.

   {
   BER_Object obj = get_next_object();
   obj.assert_is_a(type_tag, ASN1_Tag(class_tag | CONSTRUCTED));
 
   BER_Decoder result(&obj.value[0], obj.value.size());
   result.parent = this;
   return result;
   }

References Botan::BER_Object::assert_is_a(), BER_Decoder(), Botan::CONSTRUCTED, get_next_object(), Botan::MemoryRegion< T >::size(), and Botan::BER_Object::value.

Referenced by Botan::DL_Group::BER_decode(), Botan::PK_Verifier::check_signature(), Botan::AlgorithmIdentifier::decode_from(), Botan::AlternativeName::decode_from(), Botan::Attribute::decode_from(), Botan::CRL_Entry::decode_from(), Botan::Extensions::decode_from(), and Botan::X509_DN::decode_from().

verify_end()

BER_Decoder & Botan::BER_Decoder::verify_end

(

)

Definition at line 163 of file ber_dec.cpp.

   {
   if(!source->end_of_data() || (pushed.type_tag != NO_OBJECT))
      throw Invalid_State("BER_Decoder::verify_end called, but data remains");
   return (*this);
   }

References BER_Decoder(), Botan::Invalid_State::Invalid_State(), and Botan::NO_OBJECT.

Referenced by Botan::DL_Group::BER_decode(), Botan::AlternativeName::decode_from(), Botan::Extensions::decode_from(), and Botan::X509_DN::decode_from().

---

The documentation for this class was generated from the following files:

• src/asn1/ber_dec.h
• src/asn1/ber_dec.cpp