/* * DataSource * (C) 1999-2007 Jack Lloyd * 2012 Markus Wanner * * Botan is released under the Simplified BSD License (see license.txt) */ #ifndef BOTAN_DATA_SRC_H__ #define BOTAN_DATA_SRC_H__ #include #include #include namespace Botan { /** * This class represents an abstract data source object. */ class BOTAN_DLL DataSource { public: /** * Read from the source. Moves the internal offset so that every * call to read will return a new portion of the source. * * @param out the byte array to write the result to * @param length the length of the byte array out * @return length in bytes that was actually read and put * into out */ virtual size_t read(byte out[], size_t length) = 0; virtual bool check_available(size_t n) = 0; /** * Read from the source but do not modify the internal * offset. Consecutive calls to peek() will return portions of * the source starting at the same position. * * @param out the byte array to write the output to * @param length the length of the byte array out * @param peek_offset the offset into the stream to read at * @return length in bytes that was actually read and put * into out */ virtual size_t peek(byte out[], size_t length, size_t peek_offset) const = 0; /** * Test whether the source still has data that can be read. * @return true if there is still data to read, false otherwise */ virtual bool end_of_data() const = 0; /** * return the id of this data source * @return std::string representing the id of this data source */ virtual std::string id() const { return ""; } /** * Read one byte. * @param out the byte to read to * @return length in bytes that was actually read and put * into out */ size_t read_byte(byte& out); /** * Peek at one byte. * @param out an output byte * @return length in bytes that was actually read and put * into out */ size_t peek_byte(byte& out) const; /** * Discard the next N bytes of the data * @param N the number of bytes to discard * @return number of bytes actually discarded */ size_t discard_next(size_t N); /** * @return number of bytes read so far. */ virtual size_t get_bytes_read() const = 0; DataSource() {} virtual ~DataSource() {} DataSource& operator=(const DataSource&) = delete; DataSource(const DataSource&) = delete; }; /** * This class represents a Memory-Based DataSource */ class BOTAN_DLL DataSource_Memory : public DataSource { public: size_t read(byte[], size_t) override; size_t peek(byte[], size_t, size_t) const override; bool check_available(size_t n) override; bool end_of_data() const override; /** * Construct a memory source that reads from a string * @param in the string to read from */ DataSource_Memory(const std::string& in); /** * Construct a memory source that reads from a byte array * @param in the byte array to read from * @param length the length of the byte array */ DataSource_Memory(const byte in[], size_t length) : m_source(in, in + length), m_offset(0) {} /** * Construct a memory source that reads from a secure_vector * @param in the MemoryRegion to read from */ DataSource_Memory(const secure_vector& in) : m_source(in), m_offset(0) {} /** * Construct a memory source that reads from a std::vector * @param in the MemoryRegion to read from */ DataSource_Memory(const std::vector& in) : m_source(in.begin(), in.end()), m_offset(0) {} size_t get_bytes_read() const override { return m_offset; } private: secure_vector m_source; size_t m_offset; }; /** * This class represents a Stream-Based DataSource. */ class BOTAN_DLL DataSource_Stream : public DataSource { public: size_t read(byte[], size_t) override; size_t peek(byte[], size_t, size_t) const override; bool check_available(size_t n) override; bool end_of_data() const override; std::string id() const override; DataSource_Stream(std::istream&, const std::string& id = ""); /** * Construct a Stream-Based DataSource from file * @param file the name of the file * @param use_binary whether to treat the file as binary or not */ DataSource_Stream(const std::string& file, bool use_binary = false); DataSource_Stream(const DataSource_Stream&) = delete; DataSource_Stream& operator=(const DataSource_Stream&) = delete; ~DataSource_Stream(); size_t get_bytes_read() const override { return m_total_read; } private: const std::string m_identifier; std::istream* m_source_p; std::istream& m_source; size_t m_total_read; }; } #endif