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/*
* BER Decoder
* (C) 1999-2010 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#ifndef BOTAN_BER_DECODER_H__
#define BOTAN_BER_DECODER_H__
#include <botan/asn1_oid.h>
#include <botan/data_src.h>
namespace Botan {
/**
* BER Decoding Object
*/
class BOTAN_DLL BER_Decoder
{
public:
BER_Object get_next_object();
void push_back(const BER_Object&);
bool more_items() const;
BER_Decoder& verify_end();
BER_Decoder& discard_remaining();
BER_Decoder start_cons(ASN1_Tag, ASN1_Tag = UNIVERSAL);
BER_Decoder& end_cons();
BER_Decoder& raw_bytes(MemoryRegion<byte>&);
BER_Decoder& decode_null();
BER_Decoder& decode(bool&);
BER_Decoder& decode(u32bit&);
BER_Decoder& decode(class BigInt&);
BER_Decoder& decode(MemoryRegion<byte>&, ASN1_Tag);
BER_Decoder& decode(bool&, ASN1_Tag, ASN1_Tag = CONTEXT_SPECIFIC);
BER_Decoder& decode(u32bit&, ASN1_Tag, ASN1_Tag = CONTEXT_SPECIFIC);
BER_Decoder& decode(class BigInt&,
ASN1_Tag, ASN1_Tag = CONTEXT_SPECIFIC);
BER_Decoder& decode(MemoryRegion<byte>&, ASN1_Tag,
ASN1_Tag, ASN1_Tag = CONTEXT_SPECIFIC);
BER_Decoder& decode(class ASN1_Object&);
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());
template<typename T>
BER_Decoder& decode_list(std::vector<T>& out,
bool clear_out = true);
template<typename T>
BER_Decoder& decode_and_check(const T& expected,
const std::string& error_msg)
{
T actual;
decode(actual);
if(actual != expected)
throw Decoding_Error(error_msg);
return (*this);
}
BER_Decoder& decode_optional_string(MemoryRegion<byte>&,
ASN1_Tag, u16bit);
BER_Decoder(DataSource&);
BER_Decoder(const byte[], u32bit);
BER_Decoder(const MemoryRegion<byte>&);
BER_Decoder(const BER_Decoder&);
~BER_Decoder();
private:
BER_Decoder& operator=(const BER_Decoder&) { return (*this); }
BER_Decoder* parent;
DataSource* source;
BER_Object pushed;
mutable bool owns;
};
/*
* Decode an OPTIONAL or DEFAULT element
*/
template<typename T>
BER_Decoder& BER_Decoder::decode_optional(T& out,
ASN1_Tag type_tag,
ASN1_Tag class_tag,
const T& default_value)
{
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);
}
/*
* Decode a list of homogenously typed values
*/
template<typename T>
BER_Decoder& BER_Decoder::decode_list(std::vector<T>& vec, bool clear_it)
{
if(clear_it)
vec.clear();
while(more_items())
{
T value;
decode(value);
vec.push_back(value);
}
return (*this);
}
}
#endif
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