diff options
| -rw-r--r-- | src/lib/asn1/ber_dec.cpp | 111 | ||||
| -rw-r--r-- | src/lib/asn1/ber_dec.h | 164 |
2 files changed, 194 insertions, 81 deletions
diff --git a/src/lib/asn1/ber_dec.cpp b/src/lib/asn1/ber_dec.cpp index 35f1a53b5..313e7fd15 100644 --- a/src/lib/asn1/ber_dec.cpp +++ b/src/lib/asn1/ber_dec.cpp @@ -1,6 +1,6 @@ /* * BER Decoder -* (C) 1999-2008,2015,2017 Jack Lloyd +* (C) 1999-2008,2015,2017,2018 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ @@ -145,6 +145,51 @@ size_t find_eoc(DataSource* ber, size_t allow_indef) return length; } +class DataSource_BERObject final : public DataSource + { + public: + size_t read(uint8_t out[], size_t length) override + { + BOTAN_ASSERT_NOMSG(m_offset <= m_obj.length()); + const size_t got = std::min<size_t>(m_obj.length() - m_offset, length); + copy_mem(out, m_obj.bits() + m_offset, got); + m_offset += got; + return got; + } + + size_t peek(uint8_t out[], size_t length, size_t peek_offset) const override + { + BOTAN_ASSERT_NOMSG(m_offset <= m_obj.length()); + const size_t bytes_left = m_obj.length() - m_offset; + + if(peek_offset >= bytes_left) + return 0; + + const size_t got = std::min(bytes_left - peek_offset, length); + copy_mem(out, m_obj.bits() + peek_offset, got); + return got; + } + + bool check_available(size_t n) override + { + BOTAN_ASSERT_NOMSG(m_offset <= m_obj.length()); + return (n <= (m_obj.length() - m_offset)); + } + + bool end_of_data() const override + { + return get_bytes_read() == m_obj.length(); + } + + size_t get_bytes_read() const override { return m_offset; } + + explicit DataSource_BERObject(BER_Object&& obj) : m_obj(std::move(obj)), m_offset(0) {} + + private: + BER_Object m_obj; + size_t m_offset; + }; + } /* @@ -225,12 +270,6 @@ BER_Object BER_Decoder::get_next_object() return next; } -BER_Decoder& BER_Decoder::get_next(BER_Object& ber) - { - ber = get_next_object(); - return (*this); - } - /* * Push a object back into the stream */ @@ -241,18 +280,18 @@ void BER_Decoder::push_back(const BER_Object& obj) m_pushed = obj; } -/* -* Begin decoding a CONSTRUCTED type -*/ -BER_Decoder BER_Decoder::start_cons(ASN1_Tag type_tag, - ASN1_Tag class_tag) +void BER_Decoder::push_back(BER_Object&& obj) + { + if(m_pushed.is_set()) + throw Invalid_State("BER_Decoder: Only one push back is allowed"); + m_pushed = std::move(obj); + } + +BER_Decoder BER_Decoder::start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag) { BER_Object obj = get_next_object(); obj.assert_is_a(type_tag, ASN1_Tag(class_tag | CONSTRUCTED)); - - BER_Decoder result(obj.bits(), obj.length()); - result.m_parent = this; - return result; + return BER_Decoder(std::move(obj), this); } /* @@ -261,14 +300,17 @@ BER_Decoder BER_Decoder::start_cons(ASN1_Tag type_tag, BER_Decoder& BER_Decoder::end_cons() { if(!m_parent) - throw Invalid_State("BER_Decoder::end_cons called with NULL parent"); + throw Invalid_State("BER_Decoder::end_cons called with null parent"); if(!m_source->end_of_data()) throw Decoding_Error("BER_Decoder::end_cons called with data left"); return (*m_parent); } -BER_Decoder::BER_Decoder(const BER_Object& obj) : BER_Decoder(obj.bits(), obj.length()) +BER_Decoder::BER_Decoder(BER_Object&& obj, BER_Decoder* parent) { + m_data_src.reset(new DataSource_BERObject(std::move(obj))); + m_source = m_data_src.get(); + m_parent = parent; } /* @@ -340,30 +382,6 @@ BER_Decoder& BER_Decoder::decode_null() return (*this); } -/* -* Decode a BER encoded BOOLEAN -*/ -BER_Decoder& BER_Decoder::decode(bool& out) - { - return decode(out, BOOLEAN, UNIVERSAL); - } - -/* -* Decode a small BER encoded INTEGER -*/ -BER_Decoder& BER_Decoder::decode(size_t& out) - { - return decode(out, INTEGER, UNIVERSAL); - } - -/* -* Decode a BER encoded INTEGER -*/ -BER_Decoder& BER_Decoder::decode(BigInt& out) - { - return decode(out, INTEGER, UNIVERSAL); - } - BER_Decoder& BER_Decoder::decode_octet_string_bigint(BigInt& out) { secure_vector<uint8_t> out_vec; @@ -372,13 +390,6 @@ BER_Decoder& BER_Decoder::decode_octet_string_bigint(BigInt& out) return (*this); } -std::vector<uint8_t> BER_Decoder::get_next_octet_string() - { - std::vector<uint8_t> out_vec; - decode(out_vec, OCTET_STRING); - return out_vec; - } - /* * Decode a BER encoded BOOLEAN */ @@ -405,6 +416,8 @@ BER_Decoder& BER_Decoder::decode(size_t& out, BigInt integer; decode(integer, type_tag, class_tag); + if(integer.is_negative()) + if(integer.bits() > 32) throw BER_Decoding_Error("Decoded integer value larger than expected"); diff --git a/src/lib/asn1/ber_dec.h b/src/lib/asn1/ber_dec.h index d454c45d6..2086eacd3 100644 --- a/src/lib/asn1/ber_dec.h +++ b/src/lib/asn1/ber_dec.h @@ -1,6 +1,6 @@ /* * BER Decoder -* (C) 1999-2010 Jack Lloyd +* (C) 1999-2010,2018 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ @@ -13,28 +13,103 @@ namespace Botan { +class BigInt; + /** * BER Decoding Object */ class BOTAN_PUBLIC_API(2,0) BER_Decoder final { public: + /** + * Set up to BER decode the data in buf of length len + */ + BER_Decoder(const uint8_t buf[], size_t len); + + /** + * Set up to BER decode the data in vec + */ + explicit BER_Decoder(const secure_vector<uint8_t>& vec); + + /** + * Set up to BER decode the data in vec + */ + explicit BER_Decoder(const std::vector<uint8_t>& vec); + + /** + * Set up to BER decode the data in src + */ + explicit BER_Decoder(DataSource& src); + + /** + * Set up to BER decode the data in obj + */ + BER_Decoder(const BER_Object& obj) : + BER_Decoder(obj.bits(), obj.length()) {} + + BER_Decoder(const BER_Decoder& other); + + BER_Decoder& operator=(const BER_Decoder&) = delete; + + /** + * Get the next object in the data stream. + * If EOF, returns an object with type NO_OBJECT. + */ BER_Object get_next_object(); - std::vector<uint8_t> get_next_octet_string(); + BER_Decoder& get_next(BER_Object& ber) + { + ber = get_next_object(); + return (*this); + } + /** + * Push an object back onto the stream. Throws if another + * object was previously pushed and has not been subsequently + * read out. + */ void push_back(const BER_Object& obj); + /** + * Push an object back onto the stream. Throws if another + * object was previously pushed and has not been subsequently + * read out. + */ + void push_back(BER_Object&& obj); + + /** + * Return true if there is at least one more item remaining + */ bool more_items() const; + + /** + * Verify the stream is concluded, throws otherwise. + * Returns (*this) + */ BER_Decoder& verify_end(); + + /** + * Verify the stream is concluded, throws otherwise. + * Returns (*this) + */ BER_Decoder& verify_end(const std::string& err_msg); + /** + * Discard any data that remains unread + * Returns (*this) + */ BER_Decoder& discard_remaining(); - BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag = UNIVERSAL); - BER_Decoder& end_cons(); + /** + * Start decoding a constructed data (sequence or set) + */ + BER_Decoder start_cons(ASN1_Tag type_tag, ASN1_Tag class_tag = UNIVERSAL); - BER_Decoder& get_next(BER_Object& ber); + /** + * Finish decoding a constructed data, throws if any data remains. + * Returns the parent of *this (ie the object on which start_cons was called). + */ + BER_Decoder& end_cons(); /** * Get next object and copy value to POD type @@ -82,9 +157,37 @@ class BOTAN_PUBLIC_API(2,0) BER_Decoder final } BER_Decoder& decode_null(); - BER_Decoder& decode(bool& v); - BER_Decoder& decode(size_t& v); - BER_Decoder& decode(class BigInt& v); + + /** + * Decode a BER encoded BOOLEAN + */ + BER_Decoder& decode(bool& out) + { + return decode(out, BOOLEAN, UNIVERSAL); + } + + /* + * Decode a small BER encoded INTEGER + */ + BER_Decoder& decode(size_t& out) + { + return decode(out, INTEGER, UNIVERSAL); + } + + /* + * Decode a BER encoded INTEGER + */ + BER_Decoder& decode(BigInt& out) + { + return decode(out, INTEGER, UNIVERSAL); + } + + std::vector<uint8_t> get_next_octet_string() + { + std::vector<uint8_t> out_vec; + decode(out_vec, OCTET_STRING); + return out_vec; + } /* * BER decode a BIT STRING or OCTET STRING @@ -103,7 +206,7 @@ class BOTAN_PUBLIC_API(2,0) BER_Decoder final ASN1_Tag type_tag, ASN1_Tag class_tag = CONTEXT_SPECIFIC); - BER_Decoder& decode(class BigInt& v, + BER_Decoder& decode(BigInt& v, ASN1_Tag type_tag, ASN1_Tag class_tag = CONTEXT_SPECIFIC); @@ -121,11 +224,14 @@ class BOTAN_PUBLIC_API(2,0) BER_Decoder final ASN1_Tag type_tag = NO_OBJECT, ASN1_Tag class_tag = NO_OBJECT); - BER_Decoder& decode_octet_string_bigint(class BigInt& b); + /** + * Decode an integer value which is typed as an octet string + */ + BER_Decoder& decode_octet_string_bigint(BigInt& b); uint64_t decode_constrained_integer(ASN1_Tag type_tag, - ASN1_Tag class_tag, - size_t T_bytes); + ASN1_Tag class_tag, + size_t T_bytes); template<typename T> BER_Decoder& decode_integer_type(T& out) { @@ -190,36 +296,27 @@ class BOTAN_PUBLIC_API(2,0) BER_Decoder final if(obj.is_a(type_tag, class_tag)) { if((class_tag & CONSTRUCTED) && (class_tag & CONTEXT_SPECIFIC)) + { BER_Decoder(obj).decode(out, real_type).verify_end(); + } else { - push_back(obj); + push_back(std::move(obj)); decode(out, real_type, type_tag, class_tag); } } else { out.clear(); - push_back(obj); + push_back(std::move(obj)); } return (*this); } - BER_Decoder& operator=(const BER_Decoder&) = delete; - - explicit BER_Decoder(DataSource&); - - BER_Decoder(const uint8_t[], size_t); - - explicit BER_Decoder(const BER_Object& obj); - - explicit BER_Decoder(const secure_vector<uint8_t>&); - - explicit BER_Decoder(const std::vector<uint8_t>& vec); - - BER_Decoder(const BER_Decoder&); private: + BER_Decoder(BER_Object&& obj, BER_Decoder* parent); + BER_Decoder* m_parent = nullptr; BER_Object m_pushed; // either m_data_src.get() or an unowned pointer @@ -241,17 +338,19 @@ BER_Decoder& BER_Decoder::decode_optional(T& out, if(obj.is_a(type_tag, class_tag)) { if((class_tag & CONSTRUCTED) && (class_tag & CONTEXT_SPECIFIC)) + { BER_Decoder(obj).decode(out).verify_end(); + } else { - push_back(obj); + push_back(std::move(obj)); decode(out, type_tag, class_tag); } } else { out = default_value; - push_back(obj); + push_back(std::move(obj)); } return (*this); @@ -274,13 +373,14 @@ BER_Decoder& BER_Decoder::decode_optional_implicit( if(obj.is_a(type_tag, class_tag)) { obj.set_tagging(real_type, real_class); - push_back(obj); + push_back(std::move(obj)); decode(out, real_type, real_class); } else { + // Not what we wanted, push it back on the stream out = default_value; - push_back(obj); + push_back(std::move(obj)); } return (*this); @@ -299,7 +399,7 @@ BER_Decoder& BER_Decoder::decode_list(std::vector<T>& vec, { T value; list.decode(value); - vec.push_back(value); + vec.push_back(std::move(value)); } list.end_cons(); |