Merge tag '0.5.3' into debian

0.5.3

1 files changed, 110 insertions, 152 deletions

diff --git a/rfc4251.H b/rfc4251.H
index 7d4c0d3..41d466f 100644
--- a/rfc4251.H
+++ b/rfc4251.H
@@ -5,12 +5,14 @@
  * rfc4251::boolean	boolean
  * rfc4251::uint32	uint32
  * rfc4251::uint64	uint64
- * rfc4251::string	string, incl. mpint and name-list
+ * rfc4251::string	string
+ * rfc4251::mpint	mpint
+ * rfc4251::name_list	name-list
  *
  * those structs contain the objects in their RFC 4251 representation,
  * conversions are provided via constructors and cast operators
  *
- * Copyright (C) 2013-2015 Timo Weingärtner <timo@tiwe.de>
+ * Copyright (C) 2013-2015,2021 Timo Weingärtner <timo@tiwe.de>
  *
  * This file is part of ssh-agent-filter.
  *
@@ -28,187 +30,143 @@
  * along with ssh-agent-filter.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <type_traits>
+#include <cstdint>
+#include <array>
 #include <vector>
 #include <string>
 #include <iostream>
 #include <limits>
 #include <stdexcept>
-#include <arpa/inet.h>	// ntohl() / htonl()
 #include <gmpxx.h>
 #include <boost/operators.hpp>
 
 namespace rfc4251 {
 
-struct byte {
-	union {
-		uint8_t value;
-		char buf[1];
-	};
-
-	byte () = default;
-	explicit byte (uint8_t v) : value(v) {}
-	inline explicit byte (std::istream &);
-
-	operator uint8_t () const { return value; }
-};
-
-inline std::istream & operator>> (std::istream & is, byte & x) {
-	return is.read(x.buf, sizeof(x.buf));
-}
-
-inline std::ostream & operator<< (std::ostream & os, byte const & x) {
-	return os.write(x.buf, sizeof(x.buf));
-}
+namespace internal {
+	template<typename T>
+	constexpr inline auto host_to_network (T value) noexcept {
+		static_assert(std::is_unsigned_v<T>, "shift is only supported on unsigned");
+
+		std::array<char, sizeof(T)> ret;
+		for (auto it{rbegin(ret)}; it != rend(ret); ++it) {
+			*it = value & 0xff;
+			if constexpr (sizeof(T) > 1) value >>= 8;
+		}
+		return ret;
+	}
 
-inline byte::byte (std::istream & is) {
-	is >> *this;
-}
+	template<typename T>
+	constexpr inline auto network_to_host (std::array<char, sizeof(T)> const buf) noexcept {
+		static_assert(std::is_unsigned_v<T>, "shift is only supported on unsigned");
 
-struct boolean {
-	union {
-		bool value;
-		char buf[1];
-	};
+		T ret{0};
+		for (auto it{cbegin(buf)}; it != cend(buf); ++it) {
+			if constexpr (sizeof(T) > 1) ret <<= 8;
+			ret |= static_cast<uint8_t>(*it);
+		}
+		return ret;
+	}
 
-	boolean () = default;
-	explicit boolean (uint8_t v) : value(v) {}
-	inline explicit boolean (std::istream &);
+	template<typename T>
+	struct fixed_length {
+		static_assert(std::is_unsigned_v<T>, "support for signed types might need more work");
 
-	operator uint8_t () const { return value; }
-};
+		std::array<char, sizeof(T)> buf{};
 
-inline std::istream & operator>> (std::istream & is, boolean & x) {
-	return is.read(x.buf, sizeof(x.buf));
-}
+		constexpr fixed_length () noexcept = default;
+		constexpr explicit fixed_length (T const v) noexcept : buf{host_to_network(v)} {}
+		explicit fixed_length (std::istream & is) { is >> *this; }
 
-inline std::ostream & operator<< (std::ostream & os, boolean const & x) {
-	return os.write(x.buf, sizeof(x.buf));
-}
+		constexpr operator T () const noexcept { return network_to_host<T>(buf); }
 
-inline boolean::boolean (std::istream & is) {
-	is >> *this;
-}
-
-struct uint32 {
-	union {
-		uint32_t value;
-		char buf[4];
+		friend std::istream & operator>> (std::istream & is, fixed_length & x) {
+			return is.read(x.buf.data(), x.buf.size());
+		}
+		friend std::ostream & operator<< (std::ostream & os, fixed_length const & x) {
+			return os.write(x.buf.data(), x.buf.size());
+		}
 	};
 
-	uint32 () = default;
-	explicit uint32 (uint32_t v) { value = htonl(v); }
-	inline explicit uint32 (std::istream &);
-
-	operator uint32_t () const { return ntohl(value); }
-};
-
-inline std::istream & operator>> (std::istream & is, uint32 & x) {
-	return is.read(x.buf, sizeof(x.buf));
-}
-
-inline std::ostream & operator<< (std::ostream & os, uint32 const & x) {
-	return os.write(x.buf, sizeof(x.buf));
-}
+	template<typename Length_Type>
+	struct variable_length  : boost::totally_ordered<variable_length<Length_Type>> {
+		using length_type = Length_Type;
+		static_assert(std::is_unsigned_v<length_type>, "negative lengths are not supported");
+
+		std::vector<char> buf;
+
+		variable_length () = default;
+		explicit variable_length (std::istream & is) { is >> *this; }
+
+		size_t size () const noexcept { return buf.size(); }
+		char const * data () const noexcept { return buf.data(); }
+		char * data () noexcept { return buf.data(); }
+
+		friend std::istream & operator>> (std::istream & is, variable_length & v) {
+			if (length_type const len{fixed_length<length_type>{is}}; is) {
+				v.buf.clear();
+				v.buf.resize(len);
+				is.read(v.buf.data(), len);
+			}
+			return is;
+		}
+		friend std::ostream & operator<< (std::ostream & os, variable_length const & v) {
+			check_length_against_limit(v.buf.size());
+			if (os << fixed_length<length_type>{static_cast<length_type>(v.buf.size())})
+				os.write(v.buf.data(), v.buf.size());
+			return os;
+		}
+		friend bool operator== (variable_length const & l, variable_length const & r) {
+			return l.buf == r.buf;
+		}
+		friend bool operator< (variable_length const & l, variable_length const & r) {
+			return l.buf < r.buf;
+		}
+
+		constexpr static void check_length_against_limit(size_t const length) {
+			if (length > std::numeric_limits<length_type>::max())
+				throw std::length_error{"numeric limit for length field in rfc4251::variable_length type exceeded"};
+		}
 
-inline uint32::uint32 (std::istream & is) {
-	is >> *this;
+	};
 }
 
-struct uint64 {
-	union {
-		uint64_t value;
-		char buf[8];
-	};
+using byte    = internal::fixed_length<uint8_t>;
+using boolean = internal::fixed_length<bool>;
+using uint32  = internal::fixed_length<uint32_t>;
+using uint64  = internal::fixed_length<uint64_t>;
 
-	uint64 () = default;
-	inline explicit uint64 (uint64_t v);
-	inline explicit uint64 (std::istream &);
+struct string : internal::variable_length<uint32_t> {
+	using variable_length::variable_length;
 
-	inline explicit operator uint64_t () const;
-};
-
-inline uint64::uint64 (uint64_t v) {
-	for (int_fast8_t i{7}; i >= 0; --i) {
-		buf[i] = v & 0xff;
-		v >>= 8;
+	inline explicit string (char const * s, size_t l) {
+		check_length_against_limit(l);
+		buf.insert(buf.end(), s, s + l);
 	}
-}
-
-inline uint64::operator uint64_t () const {
-	uint64_t ret{0};
-	for (uint_fast8_t i{0}; i < 8; ++i) {
-		ret <<= 8;
-		ret |= static_cast<uint8_t>(buf[i]);
+	explicit string (std::string const & s) : string{s.data(), s.size()} {}
+	string (std::initializer_list<char> init) {
+		check_length_against_limit(init.size());
+		buf = init;
 	}
-	return ret;
-}
-
-inline std::istream & operator>> (std::istream & is, uint64 & x) {
-	return is.read(x.buf, sizeof(x.buf));
-}
 
-inline std::ostream & operator<< (std::ostream & os, uint64 const & x) {
-	return os.write(x.buf, sizeof(x.buf));
-}
-
-inline uint64::uint64 (std::istream & is) {
-	is >> *this;
-}
+	operator std::string () const { return {buf.cbegin(), buf.cend()}; }
+};
 
-struct string : boost::totally_ordered<string> {
-	std::vector<char> value;
+struct name_list : internal::variable_length<uint32_t> {
+	using variable_length::variable_length;
+	
+	explicit name_list (std::vector<std::string> const &);
 	
-	string () = default;
-	inline explicit string (char const *, size_t);
-	explicit string (std::string const & s) : string{s.data(), s.size()} {}
-	explicit string (std::vector<std::string> const &);
-	explicit string (mpz_srcptr);
-	explicit string (mpz_class const & x) : string{x.get_mpz_t()} {}
-	inline explicit string (std::istream &);
-
-	size_t size () const { return value.size(); }
-	char const * data () const { return value.data(); }
-	char * data () { return value.data(); }
-
-	operator std::string () const { return {value.begin(), value.end()}; }
 	operator std::vector<std::string> () const;
-	operator mpz_class () const;
 };
 
-inline string::string (char const * s, size_t l) {
-	if (l > std::numeric_limits<uint32_t>::max())
-		throw std::length_error{"32-bit limit for rfc4251::string exceeded"};
-	value.insert(value.end(), s, s + l);
-}
-
-inline std::istream & operator>> (std::istream & is, string & s) {
-	s.value.clear();
-	uint32 len;
-	if (is >> len) {
-		s.value.resize(len);
-		is.read(s.value.data(), len);
-	}
-	return is;
-}
-
-inline std::ostream & operator<< (std::ostream & os, string const & s) {
-	if (s.value.size() > std::numeric_limits<uint32_t>::max())
-		throw std::length_error{"32-bit limit for rfc4251::string exceeded"};
-	if (os << uint32{static_cast<uint32_t>(s.value.size())})
-		os.write(s.value.data(), s.value.size());
-	return os;
-}
-
-inline string::string (std::istream & is) {
-	is >> *this;
-}
-
-inline bool operator== (string const & l, string const & r) {
-	return l.value == r.value;
-}
-
-inline bool operator< (string const & l, string const & r) {
-	return l.value < r.value;
-}
+struct mpint : internal::variable_length<uint32_t> {
+	using variable_length::variable_length;
+	
+	explicit mpint (mpz_srcptr);
+	explicit mpint (mpz_class const & x) : mpint{x.get_mpz_t()} {}
+	
+	operator mpz_class () const;
+};
 
 }