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Diffstat (limited to 'src/lib/asn1/ber_dec.h')
| -rw-r--r-- | src/lib/asn1/ber_dec.h | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/src/lib/asn1/ber_dec.h b/src/lib/asn1/ber_dec.h new file mode 100644 index 000000000..ebfa91c85 --- /dev/null +++ b/src/lib/asn1/ber_dec.h @@ -0,0 +1,260 @@ +/* +* 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(); + + std::vector<byte> get_next_octet_string(); + + void push_back(const BER_Object& obj); + + bool more_items() const; + BER_Decoder& verify_end(); + BER_Decoder& discard_remaining(); + + BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag = UNIVERSAL); + BER_Decoder& end_cons(); + + BER_Decoder& get_next(BER_Object& ber); + + BER_Decoder& raw_bytes(secure_vector<byte>& v); + BER_Decoder& raw_bytes(std::vector<byte>& v); + + BER_Decoder& decode_null(); + BER_Decoder& decode(bool& v); + BER_Decoder& decode(size_t& v); + BER_Decoder& decode(class BigInt& v); + BER_Decoder& decode(std::vector<byte>& v, ASN1_Tag type_tag); + BER_Decoder& decode(secure_vector<byte>& v, ASN1_Tag type_tag); + + BER_Decoder& decode(bool& v, + ASN1_Tag type_tag, + ASN1_Tag class_tag = CONTEXT_SPECIFIC); + + BER_Decoder& decode(size_t& v, + ASN1_Tag type_tag, + ASN1_Tag class_tag = CONTEXT_SPECIFIC); + + BER_Decoder& decode(class BigInt& v, + ASN1_Tag type_tag, + ASN1_Tag class_tag = CONTEXT_SPECIFIC); + + BER_Decoder& decode(std::vector<byte>& v, + ASN1_Tag real_type, + ASN1_Tag type_tag, + ASN1_Tag class_tag = CONTEXT_SPECIFIC); + + BER_Decoder& decode(secure_vector<byte>& v, + ASN1_Tag real_type, + ASN1_Tag type_tag, + ASN1_Tag class_tag = CONTEXT_SPECIFIC); + + BER_Decoder& decode(class ASN1_Object& obj, + ASN1_Tag type_tag = NO_OBJECT, + ASN1_Tag class_tag = NO_OBJECT); + + BER_Decoder& decode_octet_string_bigint(class BigInt& b); + + u64bit decode_constrained_integer(ASN1_Tag type_tag, + ASN1_Tag class_tag, + size_t T_bytes); + + template<typename T> BER_Decoder& decode_integer_type(T& out) + { + return decode_integer_type<T>(out, INTEGER, UNIVERSAL); + } + + template<typename T> + BER_Decoder& decode_integer_type(T& out, + ASN1_Tag type_tag, + ASN1_Tag class_tag = CONTEXT_SPECIFIC) + { + out = decode_constrained_integer(type_tag, class_tag, sizeof(out)); + return (*this); + } + + 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_optional_implicit( + T& out, + ASN1_Tag type_tag, + ASN1_Tag class_tag, + ASN1_Tag real_type, + ASN1_Tag real_class, + const T& default_value = T()); + + template<typename T> + BER_Decoder& decode_list(std::vector<T>& out, + ASN1_Tag type_tag = SEQUENCE, + ASN1_Tag class_tag = UNIVERSAL); + + 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); + } + + /* + * Decode an OPTIONAL string type + */ + template<typename Alloc> + BER_Decoder& decode_optional_string(std::vector<byte, Alloc>& out, + ASN1_Tag real_type, + u16bit type_no, + ASN1_Tag class_tag = CONTEXT_SPECIFIC) + { + BER_Object obj = get_next_object(); + + ASN1_Tag type_tag = static_cast<ASN1_Tag>(type_no); + + if(obj.type_tag == type_tag && obj.class_tag == class_tag) + { + if((class_tag & CONSTRUCTED) && (class_tag & CONTEXT_SPECIFIC)) + BER_Decoder(obj.value).decode(out, real_type).verify_end(); + else + { + push_back(obj); + decode(out, real_type, type_tag, class_tag); + } + } + else + { + out.clear(); + push_back(obj); + } + + return (*this); + } + + BER_Decoder& operator=(const BER_Decoder&) = delete; + + BER_Decoder(DataSource&); + + BER_Decoder(const byte[], size_t); + + BER_Decoder(const secure_vector<byte>&); + + BER_Decoder(const std::vector<byte>& vec); + + BER_Decoder(const BER_Decoder&); + ~BER_Decoder(); + private: + 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) && (class_tag & CONTEXT_SPECIFIC)) + 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 an OPTIONAL or DEFAULT element +*/ +template<typename T> +BER_Decoder& BER_Decoder::decode_optional_implicit( + T& out, + ASN1_Tag type_tag, + ASN1_Tag class_tag, + ASN1_Tag real_type, + ASN1_Tag real_class, + const T& default_value) + { + BER_Object obj = get_next_object(); + + if(obj.type_tag == type_tag && obj.class_tag == class_tag) + { + obj.type_tag = real_type; + obj.class_tag = real_class; + push_back(obj); + decode(out, real_type, real_class); + } + 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, + ASN1_Tag type_tag, + ASN1_Tag class_tag) + { + BER_Decoder list = start_cons(type_tag, class_tag); + + while(list.more_items()) + { + T value; + list.decode(value); + vec.push_back(value); + } + + list.end_cons(); + + return (*this); + } + +} + +#endif |