modernize and improve type-safety of the DHT put implementation and test (#929)

modernize and improve type-safety of the DHT put implementation and tests. use unique_ptr instead of malloc for dht put items.

Jamfile

@@ -297,6 +297,8 @@ rule warnings ( properties * )
 		result += <cflags>/wd4251 ;
 # disable warning C4275: non DLL-interface classkey 'identifier' used as base for DLL-interface classkey 'identifier'
 		result += <cflags>/wd4275 ;
+# disable warning C4373: virtual function overrides, previous versions of the compiler did not override when parameters only differed by const/volatile qualifiers
+		result += <cflags>/wd4373 ;
 	}
 
 	return $(result) ;

bindings/python/src/session.cpp

@@ -457,9 +457,9 @@ namespace
         ses.dht_get_item(public_key, salt);
     }
 
-    void put_string(entry& e, std::array<char, 64>& sig, std::uint64_t& seq,
+    void put_string(entry& e, std::array<char, 64>& sig, std::uint64_t& seq
-                    std::string const& salt, std::string public_key, std::string private_key,
+        , std::string const& salt, std::string pk, std::string sk
-                    std::string data)
+        , std::string data)
     {
         using libtorrent::dht::sign_mutable_item;
 
@@ -467,21 +467,25 @@ namespace
         std::vector<char> buf;
         bencode(std::back_inserter(buf), e);
         ++seq;
-        sign_mutable_item(std::pair<char const*, int>(&buf[0], int(buf.size()))
+        dht::signature sign;
-                          , std::pair<char const*, int>(&salt[0], int(salt.size()))
+        sign_mutable_item(buf, salt
-                          , seq, public_key.c_str(), private_key.c_str(), sig.data());
+            , dht::sequence_number(seq)
+            , dht::public_key(pk.data())
+            , dht::secret_key(sk.data())
+            , sign);
+        sig = sign.bytes;
     }
 
     void dht_put_mutable_item(lt::session& ses, std::string private_key, std::string public_key,
-                              std::string data, std::string salt)
+        std::string data, std::string salt)
     {
         TORRENT_ASSERT(private_key.size() == 64);
         TORRENT_ASSERT(public_key.size() == 32);
         std::array<char, 32> key;
         std::copy(public_key.begin(), public_key.end(), key.begin());
         ses.dht_put_item(key, boost::bind(&put_string, _1, _2, _3, _4
-                                          , public_key, private_key, data)
+            , public_key, private_key, data)
-                         , salt);
+            , salt);
     }
 #endif
 

include/libtorrent/Makefile.am

@@ -194,6 +194,7 @@ nobase_include_HEADERS = \
   kademlia/routing_table.hpp        \
   kademlia/rpc_manager.hpp          \
   kademlia/traversal_algorithm.hpp  \
+  kademlia/types.hpp                \
   kademlia/item.hpp                 \
   kademlia/get_item.hpp             \
   kademlia/get_peers.hpp

include/libtorrent/bdecode.hpp

@@ -42,6 +42,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/aux_/disable_warnings_pop.hpp"
 
 #include "libtorrent/assert.hpp"
+#include "libtorrent/span.hpp"
 
 /*
 
@@ -238,6 +239,8 @@ struct bdecode_token
 // There are 5 different types of nodes, see type_t.
 struct TORRENT_EXPORT bdecode_node
 {
+	// TODO: 3 make this take span<char const> for buffer, and make it return a
+	// bdecode_node
 	TORRENT_EXPORT friend int bdecode(char const* start, char const* end, bdecode_node& ret
 		, error_code& ec, int* error_pos, int depth_limit
 		, int token_limit);
@@ -280,7 +283,7 @@ struct TORRENT_EXPORT bdecode_node
 	// buffer where this node is defined. For a dictionary for instance, this
 	// starts with ``d`` and ends with ``e``, and has all the content of the
 	// dictionary in between.
-	std::pair<char const*, int> data_section() const;
+	span<char const> data_section() const;
 
 	// functions with the ``list_`` prefix operate on lists. These functions are
 	// only valid if ``type()`` == ``list_t``. ``list_at()`` returns the item

include/libtorrent/ed25519.hpp

@@ -20,6 +20,8 @@ extern "C" {
 void TORRENT_EXPORT ed25519_create_seed(unsigned char *seed);
 #endif
 
+// TODO: 3 wrap these into C++ calls with proper types (dht::signature,
+// public_key and secret_key)
 void TORRENT_EXPORT ed25519_create_keypair(unsigned char *public_key, unsigned char *private_key, const unsigned char *seed);
 void TORRENT_EXPORT ed25519_sign(unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *public_key, const unsigned char *private_key);
 int TORRENT_EXPORT ed25519_verify(const unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *private_key);

include/libtorrent/hex.hpp

@@ -49,6 +49,7 @@ namespace libtorrent
 	namespace aux {
 
 	TORRENT_EXTRA_EXPORT int hex_to_int(char in);
+	// TODO: 3 take an span here instead
 	TORRENT_EXTRA_EXPORT bool is_hex(char const *in, int len);
 
 	// The overload taking a ``std::string`` converts (binary) the string ``s``
@@ -58,6 +59,7 @@ namespace libtorrent
 	// ``out``. The caller is responsible for making sure the buffer pointed to
 	// by ``out`` is large enough, i.e. has at least len * 2 bytes of space.
 	TORRENT_DEPRECATED_EXPORT std::string to_hex(std::string const& s);
+	// TODO: 3 take an span here instead
 	TORRENT_DEPRECATED_EXPORT void to_hex(char const *in, int len, char* out);
 
 	// converts the buffer [``in``, ``in`` + len) from hexadecimal to
@@ -65,6 +67,7 @@ namespace libtorrent
 	// by ``out``. The caller is responsible for making sure the buffer
 	// at ``out`` has enough space for the result to be written to, i.e.
 	// (len + 1) / 2 bytes.
+	// TODO: 3 take an span here instead
 	TORRENT_DEPRECATED_EXPORT bool from_hex(char const *in, int len, char* out);
 
 	}

include/libtorrent/kademlia/dht_storage.hpp

@@ -40,10 +40,12 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/aux_/disable_warnings_pop.hpp"
 
 #include <libtorrent/kademlia/node_id.hpp>
+#include <libtorrent/kademlia/types.hpp>
 
 #include <libtorrent/socket.hpp>
 #include <libtorrent/sha1_hash.hpp>
 #include <libtorrent/address.hpp>
+#include <libtorrent/span.hpp>
 
 namespace libtorrent
 {
@@ -164,7 +166,7 @@ namespace dht
 		// dht_settings::max_dht_items.
 		//
 		virtual void put_immutable_item(sha1_hash const& target
-			, char const* buf, int size
+			, span<char const> buf
 			, address const& addr) = 0;
 
 		// This function retrieves the sequence number of a mutable item.
@@ -173,7 +175,7 @@ namespace dht
 		// inside the out parameter seq.
 		//
 		virtual bool get_mutable_item_seq(sha1_hash const& target
-			, std::int64_t& seq) const = 0;
+			, sequence_number& seq) const = 0;
 
 		// This function retrieves the mutable stored in the DHT.
 		//
@@ -189,7 +191,7 @@ namespace dht
 		// inside the (entry) out parameter item.
 		//
 		virtual bool get_mutable_item(sha1_hash const& target
-			, std::int64_t seq, bool force_fill
+			, sequence_number seq, bool force_fill
 			, entry& item) const = 0;
 
 		// Store the item's data. This layer is only for storage.
@@ -201,11 +203,11 @@ namespace dht
 		// dht_settings::max_dht_items.
 		//
 		virtual void put_mutable_item(sha1_hash const& target
-			, char const* buf, int size
+			, span<char const> buf
-			, char const* sig
+			, signature const& sig
-			, std::int64_t seq
+			, sequence_number seq
-			, char const* pk
+			, public_key const& pk
-			, char const* salt, int salt_size
+			, span<char const> salt
 			, address const& addr) = 0;
 
 		// This function is called periodically (non-constant frequency).

include/libtorrent/kademlia/dht_tracker.hpp

@@ -106,7 +106,7 @@ namespace libtorrent { namespace dht
 
 		// key is a 32-byte binary string, the public key to look up.
 		// the salt is optional
-		void get_item(char const* key
+		void get_item(public_key const& key
 			, boost::function<void(item const&, bool)> cb
 			, std::string salt = std::string());
 
@@ -119,7 +119,7 @@ namespace libtorrent { namespace dht
 		// for mutable_item.
 		// the data_cb will be called when we get authoritative mutable_item,
 		// the cb is same as put immutable_item.
-		void put_item(char const* key
+		void put_item(public_key const& key
 			, boost::function<void(item const&, int)> cb
 			, boost::function<void(item&)> data_cb, std::string salt = std::string());
 

include/libtorrent/kademlia/find_data.hpp

@@ -65,7 +65,7 @@ struct find_data : traversal_algorithm
 {
 	typedef boost::function<void(std::vector<std::pair<node_entry, std::string> > const&)> nodes_callback;
 
-	find_data(node & node, node_id target
+	find_data(node& node, node_id target
 		, nodes_callback const& ncallback);
 
 	void got_write_token(node_id const& n, std::string const& write_token);

include/libtorrent/kademlia/get_item.hpp

@@ -46,9 +46,9 @@ public:
 	typedef boost::function<void(item const&, bool)> data_callback;
 
 	void got_data(bdecode_node const& v,
-		char const* pk,
+		public_key const& pk,
-		std::uint64_t seq,
+		sequence_number seq,
-		char const* sig);
+		signature const& sig);
 
 	// for immutable itms
 	get_item(node& dht_node
@@ -58,8 +58,8 @@ public:
 
 	// for mutable items
 	get_item(node& dht_node
-		, char const* pk
+		, public_key const& pk
-		, std::string const& salt
+		, span<char const> salt
 		, data_callback const& dcallback
 		, nodes_callback const& ncallback);
 

include/libtorrent/kademlia/item.hpp

@@ -1,6 +1,6 @@
 /*
 
-Copyright (c) 2013, Steven Siloti
+Copyright (c) 2013, Steven Siloti, Arvid Norberg
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -36,6 +36,9 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <libtorrent/sha1_hash.hpp>
 #include <libtorrent/bdecode.hpp>
 #include <libtorrent/entry.hpp>
+#include <libtorrent/span.hpp>
+#include <libtorrent/kademlia/types.hpp>
+
 #include <vector>
 #include <exception>
 #include <array>
@@ -44,19 +47,18 @@ namespace libtorrent { namespace dht
 {
 
 // calculate the target hash for an immutable item.
-sha1_hash TORRENT_EXTRA_EXPORT item_target_id(
+sha1_hash TORRENT_EXTRA_EXPORT item_target_id(span<char const> v);
-	std::pair<char const*, int> v);
 
 // calculate the target hash for a mutable item.
-sha1_hash TORRENT_EXTRA_EXPORT item_target_id(std::pair<char const*, int> salt
+sha1_hash TORRENT_EXTRA_EXPORT item_target_id(span<char const> salt
-	, char const* pk);
+	, public_key const& pk);
 
 bool TORRENT_EXTRA_EXPORT verify_mutable_item(
-	std::pair<char const*, int> v
+	span<char const> v
-	, std::pair<char const*, int> salt
+	, span<char const> salt
-	, std::uint64_t seq
+	, sequence_number seq
-	, char const* pk
+	, public_key const& pk
-	, char const* sig);
+	, signature const& sig);
 
 // TODO: since this is a public function, it should probably be moved
 // out of this header and into one with other public functions.
@@ -68,47 +70,40 @@ bool TORRENT_EXTRA_EXPORT verify_mutable_item(
 // is responsible for allocating the destination buffer that's passed in
 // as the ``sig`` argument. Typically it would be allocated on the stack.
 void TORRENT_EXPORT sign_mutable_item(
-	std::pair<char const*, int> v
+	span<char const> v
-	, std::pair<char const*, int> salt
+	, span<char const> salt
-	, std::uint64_t seq
+	, sequence_number seq
-	, char const* pk
+	, public_key const& pk
-	, char const* sk
+	, secret_key const& sk
-	, char* sig);
+	, signature& sig);
-
-enum
-{
-	item_pk_len = 32,
-	item_sk_len = 64,
-	item_sig_len = 64
-};
 
 class TORRENT_EXTRA_EXPORT item
 {
 public:
 	item() : m_seq(0), m_mutable(false)  {}
-	item(char const* pk, std::string const& salt);
+	item(public_key const& pk, span<char const> salt);
-	item(entry const& v) { assign(v); }
+	item(entry v);
-	item(entry const& v
+	item(entry v
-		, std::pair<char const*, int> salt
+		, span<char const> salt
-		, std::uint64_t seq, char const* pk, char const* sk);
+		, sequence_number seq
-	item(bdecode_node const& v) { assign(v); }
+		, public_key const& pk
+		, secret_key const& sk);
+	item(bdecode_node const& v);
 
-	void assign(entry const& v)
+	void assign(entry v);
-	{
+	void assign(entry v, span<char const> salt
-		assign(v, std::pair<char const*, int>(static_cast<char const*>(nullptr)
+		, sequence_number seq
-			, 0), 0, nullptr, nullptr);
+		, public_key const& pk
-	}
+		, secret_key const& sk);
-	void assign(entry const& v, std::pair<char const*, int> salt
+	void assign(bdecode_node const& v);
-		, std::uint64_t seq, char const* pk, char const* sk);
+	bool assign(bdecode_node const& v, span<char const> salt
-	void assign(bdecode_node const& v)
+		, sequence_number seq
-	{
+		, public_key const& pk
-		assign(v, std::pair<char const*, int>(static_cast<char const*>(nullptr)
+		, signature const& sig);
-			, 0), 0, nullptr, nullptr);
+	void assign(entry v, span<char const> salt
-	}
+		, sequence_number seq
-	bool assign(bdecode_node const& v, std::pair<char const*, int> salt
+		, public_key const& pk
-		, std::uint64_t seq, char const* pk, char const* sig);
+		, signature const& sig);
-	void assign(entry const& v, std::string salt, std::uint64_t seq
-		, char const* pk, char const* sig);
 
 	void clear() { m_value = entry(); }
 	bool empty() const { return m_value.type() == entry::undefined_t; }
@@ -116,19 +111,19 @@ public:
 	bool is_mutable() const { return m_mutable; }
 
 	entry const& value() const { return m_value; }
-	std::array<char, item_pk_len> const& pk() const
+	public_key const& pk() const
 	{ return m_pk; }
-	std::array<char, item_sig_len> const& sig() const
+	signature const& sig() const
 	{ return m_sig; }
-	std::uint64_t seq() const { return m_seq; }
+	sequence_number seq() const { return m_seq; }
 	std::string const& salt() const { return m_salt; }
 
 private:
 	entry m_value;
 	std::string m_salt;
-	std::array<char, item_pk_len> m_pk;
+	public_key m_pk;
-	std::array<char, item_sig_len> m_sig;
+	signature m_sig;
-	std::uint64_t m_seq;
+	sequence_number m_seq;
 	bool m_mutable;
 };
 

include/libtorrent/kademlia/msg.hpp

@@ -93,6 +93,7 @@ void incoming_error(entry& e, char const* msg, int error_code = 203);
 // given a redundant name to avoid clashing with libtorrent::detail
 namespace dht_detail {
 
+//#error move this to its own .hpp/.cpp pair and make it take an span instead of being a template
 TORRENT_EXPORT bool verify_message(bdecode_node const& msg, key_desc_t const desc[]
 	, bdecode_node ret[], int size, char* error, int error_size);
 

include/libtorrent/kademlia/node.hpp

@@ -150,17 +150,17 @@ public:
 		, boost::function<void(msg const&)> f);
 
 	void get_item(sha1_hash const& target, boost::function<void(item const&)> f);
-	void get_item(char const* pk, std::string const& salt, boost::function<void(item const&, bool)> f);
+	void get_item(public_key const& pk, std::string const& salt, boost::function<void(item const&, bool)> f);
 
 	void put_item(sha1_hash const& target, entry const& data, boost::function<void(int)> f);
-	void put_item(char const* pk, std::string const& salt
+	void put_item(public_key const& pk, std::string const& salt
 		, boost::function<void(item const&, int)> f
 		, boost::function<void(item&)> data_cb);
 
-	bool verify_token(std::string const& token, char const* info_hash
+	bool verify_token(std::string const& token, sha1_hash const& info_hash
 		, udp::endpoint const& addr) const;
 
-	std::string generate_token(udp::endpoint const& addr, char const* info_hash);
+	std::string generate_token(udp::endpoint const& addr, sha1_hash const& info_hash);
 
 	// the returned time is the delay until connection_timeout()
 	// should be called again the next time

include/libtorrent/kademlia/types.hpp

@@ -0,0 +1,96 @@
+/*
+
+Copyright (c) 2016, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#ifndef LIBTORRENT_TYPES_HPP
+#define LIBTORRENT_TYPES_HPP
+
+#include <cstdint>
+
+namespace libtorrent { namespace dht
+{
+	struct public_key
+	{
+		public_key() = default;
+		explicit public_key(char const* b)
+		{ std::copy(b, b + len, bytes.begin()); }
+		bool operator==(public_key const& rhs) const
+		{ return bytes == rhs.bytes; }
+		constexpr static int len = 32;
+		std::array<char, len> bytes;
+	};
+
+	struct secret_key
+	{
+		secret_key() = default;
+		explicit secret_key(char const* b)
+		{ std::copy(b, b + len, bytes.begin()); }
+		bool operator==(secret_key const& rhs) const
+		{ return bytes == rhs.bytes; }
+		constexpr static int len = 64;
+		std::array<char, len> bytes;
+	};
+
+	struct signature
+	{
+		signature() = default;
+		explicit signature(char const* b)
+		{ std::copy(b, b + len, bytes.begin()); }
+		bool operator==(signature const& rhs) const
+		{ return bytes == rhs.bytes; }
+		constexpr static int len = 64;
+		std::array<char, len> bytes;
+	};
+
+	struct sequence_number
+	{
+		sequence_number() : value(0) {}
+		explicit sequence_number(std::uint64_t v) : value(v) {}
+		sequence_number(sequence_number const& sqn) = default;
+		bool operator<(sequence_number rhs) const
+		{ return value < rhs.value; }
+		bool operator>(sequence_number rhs) const
+		{ return value > rhs.value; }
+		sequence_number& operator=(sequence_number rhs)
+		{ value = rhs.value; return *this; }
+		bool operator<=(sequence_number rhs) const
+		{ return value <= rhs.value; }
+		bool operator==(sequence_number const& rhs) const
+		{ return value == rhs.value; }
+		sequence_number& operator++()
+		{ ++value; return *this; }
+		std::uint64_t value;
+	};
+
+}}
+
+#endif // LIBTORRENT_TYPES_HPP
+

include/libtorrent/session_handle.hpp

@@ -419,7 +419,7 @@ namespace libtorrent
 		// calling the callback in between is convenient.
 		void dht_put_item(std::array<char, 32> key
 			, boost::function<void(entry&, std::array<char,64>&
-			, std::uint64_t&, std::string const&)> cb
+				, std::uint64_t&, std::string const&)> cb
 			, std::string salt = std::string());
 
 		void dht_get_peers(sha1_hash const& info_hash);

include/libtorrent/stack_allocator.hpp

@@ -84,6 +84,7 @@ namespace libtorrent { namespace aux
 			return ret;
 		}
 
+		// TODO: 3 use span<> here
 		int copy_buffer(char const* buf, int const size)
 		{
 			int const ret = int(m_storage.size());

simulation/test_dht.cpp

@@ -284,8 +284,8 @@ TORRENT_TEST(dht_dual_stack_mutable_item)
 	dht_network dht(sim, 100);
 	dht_network dht6(sim, 100, dht_network::bind_ipv6);
 
-	std::array<char, ed25519_private_key_size> sk;
+	lt::dht::secret_key sk;
-	std::array<char, ed25519_public_key_size> pk;
+	lt::dht::public_key pk;
 	int put_count = 0;
 	bool got_item = false;
 
@@ -302,7 +302,7 @@ TORRENT_TEST(dht_dual_stack_mutable_item)
 			{
 				TEST_CHECK(!got_item);
 				if (p->authoritative)
-					got_item = p->key == pk && p->item.string() == "mutable item";
+					got_item = p->key == pk.bytes && p->item.string() == "mutable item";
 			}
 		}
 		// terminate?
@@ -315,28 +315,28 @@ TORRENT_TEST(dht_dual_stack_mutable_item)
 			if (ticks == 2)
 			{
 				std::array<unsigned char, ed25519_seed_size> seed;
-				ed25519_create_keypair((unsigned char*)pk.data()
+				ed25519_create_keypair((unsigned char*)pk.bytes.data()
-					, (unsigned char*)sk.data(), seed.data());
+					, (unsigned char*)sk.bytes.data(), seed.data());
 
-				ses.dht_put_item(pk, [&](lt::entry& item, std::array<char, 64>& sig
+				ses.dht_put_item(pk.bytes, [&](lt::entry& item, std::array<char, 64>& sig
 					, std::uint64_t& seq, std::string const& salt)
 				{
 					item = "mutable item";
 					seq = 1;
 					std::vector<char> v;
+					lt::dht::signature sign;
 					lt::bencode(std::back_inserter(v), item);
-					lt::dht::sign_mutable_item(
+					lt::dht::sign_mutable_item(v, salt
-						std::make_pair(v.data(), int(v.size()))
+						, lt::dht::sequence_number(seq), pk, sk, sign);
-						, std::make_pair(salt.data(), int(salt.size()))
-						, seq, pk.data(), sk.data(), sig.data());
 					put_count++;
+					sig = sign.bytes;
 				});
 			}
 			if (ticks == 4)
 			{
 				// should be one for each stack, ipv4 and ipv6
 				TEST_EQUAL(put_count, 2);
-				ses.dht_get_item(pk);
+				ses.dht_get_item(pk.bytes);
 			}
 			if (ticks == 6)
 			{

simulation/test_dht_storage.cpp

@@ -107,7 +107,7 @@ void test_expiration(high_resolution_clock::duration const& expiry_time
 {
 	default_config cfg;
 	simulation sim(cfg);
-	sim::asio::io_service ios(sim, asio::ip::address_v4::from_string("10.0.0.1"));
+	sim::asio::io_service ios(sim, addr("10.0.0.1"));
 
 	sim::asio::high_resolution_timer timer(ios);
 	timer.expires_from_now(expiry_time);
@@ -139,16 +139,15 @@ TORRENT_TEST(dht_storage_counters)
 	s->announce_peer(n2, p3, "torrent_name1", false);
 	s->announce_peer(n3, p4, "torrent_name2", false);
 
-	s->put_immutable_item(n4, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n4, {"123", 3}, addr("124.31.75.21"));
+	s->put_immutable_item(n1, {"123", 3}, addr("124.31.75.21"));
+	s->put_immutable_item(n2, {"123", 3}, addr("124.31.75.21"));
+	s->put_immutable_item(n3, {"123", 3}, addr("124.31.75.21"));
 
-	s->put_immutable_item(n1, "123", 3, address::from_string("124.31.75.21"));
+	dht::public_key pk;
-	s->put_immutable_item(n2, "123", 3, address::from_string("124.31.75.21"));
+	dht::signature sig;
-	s->put_immutable_item(n3, "123", 3, address::from_string("124.31.75.21"));
+	s->put_mutable_item(n4, {"123", 3}, sig, sequence_number(1), pk, {"salt", 4}
-
+		, addr("124.31.75.21"));
-	char public_key[item_pk_len];
-	char signature[item_sig_len];
-	s->put_mutable_item(n4, "123", 3, signature, 1, public_key, "salt", 4
-		, address::from_string("124.31.75.21"));
 
 	dht_storage_counters c;
 	// note that we are using the aux global timer

src/alert.cpp

@@ -1886,6 +1886,7 @@ namespace libtorrent {
 		return ret;
 	}
 
+	// TODO: 3 use span<> here
 	dht_pkt_alert::dht_pkt_alert(aux::stack_allocator& alloc
 		, char const* buf, int size, dht_pkt_alert::direction_t d, udp::endpoint ep)
 		: dir(d)
@@ -1987,8 +1988,9 @@ namespace libtorrent {
 		aux::stack_allocator& alloc, void* userdata_
 		, udp::endpoint const& addr_, bdecode_node const& response)
 		: userdata(userdata_), addr(addr_), m_alloc(alloc)
-		, m_response_idx(alloc.copy_buffer(response.data_section().first, response.data_section().second))
+		, m_response_idx(alloc.copy_buffer(response.data_section().data()
-		, m_response_size(response.data_section().second)
+				, int(response.data_section().size())))
+		, m_response_size(int(response.data_section().size()))
 	{}
 
 	dht_direct_response_alert::dht_direct_response_alert(

src/bdecode.cpp

@@ -303,14 +303,14 @@ namespace libtorrent
 	bdecode_node::operator bool() const
 	{ return m_token_idx != -1; }
 
-	std::pair<char const*, int> bdecode_node::data_section() const
+	span<char const> bdecode_node::data_section() const
 	{
-		if (m_token_idx == -1) return std::make_pair(m_buffer, 0);
+		if (m_token_idx == -1) return span<char const>();
 
 		TORRENT_ASSERT(m_token_idx != -1);
 		bdecode_token const& t = m_root_tokens[m_token_idx];
 		bdecode_token const& next = m_root_tokens[m_token_idx + t.next_item];
-		return std::make_pair(m_buffer + t.offset, next.offset - t.offset);
+		return { m_buffer + t.offset, size_t(next.offset - t.offset) };
 	}
 
 	bdecode_node bdecode_node::list_at(int i) const

src/bt_peer_connection.cpp

@@ -95,8 +95,8 @@ namespace libtorrent
 		, sha1_hash const& stream_key, bool const outgoing)
 	{
 		hasher h;
-		static const char keyA[] = "keyA";
+		static const char keyA[] = {'k', 'e', 'y', 'A'};
-		static const char keyB[] = "keyB";
+		static const char keyB[] = {'k', 'e', 'y', 'B'};
 
 		// encryption rc4 longkeys
 		// outgoing connection : hash ('keyA',S,SKEY)
@@ -105,10 +105,10 @@ namespace libtorrent
 		std::array<char, 96> secret_buf;
 		mp::export_bits(secret, reinterpret_cast<std::uint8_t*>(secret_buf.data()), 8);
 
-		if (outgoing) h.update(keyA, 4); else h.update(keyB, 4);
+		if (outgoing) h.update(keyA); else h.update(keyB);
 		h.update(secret_buf);
 		h.update(stream_key);
-		const sha1_hash local_key = h.final();
+		sha1_hash const local_key = h.final();
 
 		h.reset();
 
@@ -116,10 +116,10 @@ namespace libtorrent
 		// outgoing connection : hash ('keyB',S,SKEY)
 		// incoming connection : hash ('keyA',S,SKEY)
 
-		if (outgoing) h.update(keyB, 4); else h.update(keyA, 4);
+		if (outgoing) h.update(keyB); else h.update(keyA);
 		h.update(secret_buf);
 		h.update(stream_key);
-		const sha1_hash remote_key = h.final();
+		sha1_hash const remote_key = h.final();
 
 		boost::shared_ptr<rc4_handler> ret = boost::make_shared<rc4_handler>();
 
@@ -557,27 +557,30 @@ namespace libtorrent
 		char msg[20 + 20 + 8 + 4 + 2 + 512 + 2];
 		char* ptr = msg;
 
+		static char const req1[4] = {'r', 'e', 'q', '1'};
 		// sync hash (hash('req1',S))
 		h.reset();
-		h.update("req1",4);
+		h.update(req1);
 		h.update(secret);
 		sha1_hash const sync_hash = h.final();
 
-		memcpy(ptr, sync_hash.data(), 20);
+		std::memcpy(ptr, sync_hash.data(), 20);
 		ptr += 20;
 
+		static char const req2[4] = {'r', 'e', 'q', '2'};
 		// stream key obfuscated hash [ hash('req2',SKEY) xor hash('req3',S) ]
 		h.reset();
-		h.update("req2",4);
+		h.update(req2);
 		h.update(info_hash);
 		sha1_hash const streamkey_hash = h.final();
 
+		static char const req3[4] = {'r', 'e', 'q', '3'};
 		h.reset();
-		h.update("req3",4);
+		h.update(req3);
 		h.update(secret);
 		sha1_hash const obfsc_hash = h.final() ^ streamkey_hash;
 
-		memcpy(ptr, obfsc_hash.data(), 20);
+		std::memcpy(ptr, obfsc_hash.data(), 20);
 		ptr += 20;
 
 		// Discard DH key exchange data, setup RC4 keys
@@ -726,7 +729,7 @@ namespace libtorrent
 			// if we're encrypting this buffer, we need to make a copy
 			// since we'll mutate it
 			char* buf = static_cast<char*>(malloc(size));
-			memcpy(buf, buffer, size);
+			std::memcpy(buf, buffer, size);
 			append_send_buffer(buf, size, &regular_c_free, nullptr);
 			destructor(const_cast<char*>(buffer), userdata, ref);
 		}
@@ -757,7 +760,7 @@ namespace libtorrent
 		// length of version string
 		detail::write_uint8(string_len, ptr);
 		// protocol identifier
-		memcpy(ptr, version_string, string_len);
+		std::memcpy(ptr, version_string, string_len);
 		ptr += string_len;
 		// 8 zeroes
 		memset(ptr, 0, 8);
@@ -798,7 +801,7 @@ namespace libtorrent
 
 		// info hash
 		sha1_hash const& ih = t->torrent_file().info_hash();
-		memcpy(ptr, &ih[0], 20);
+		std::memcpy(ptr, ih.data(), ih.size());
 		ptr += 20;
 
 		// peer id
@@ -810,7 +813,7 @@ namespace libtorrent
 				m_our_peer_id[i] = random() & 0xff;
 		}
 
-		memcpy(ptr, &m_our_peer_id[0], 20);
+		std::memcpy(ptr, m_our_peer_id.data(), 20);
 		ptr += 20;
 
 #ifndef TORRENT_DISABLE_LOGGING
@@ -2632,15 +2635,14 @@ namespace libtorrent
 			if (!m_sync_hash.get())
 			{
 				TORRENT_ASSERT(m_sync_bytes_read == 0);
-				hasher h;
 
+				static char const req1[4] = {'r', 'e', 'q', '1'};
 				// compute synchash (hash('req1',S))
 				std::array<char, 96> buffer;
 				mp::export_bits(m_dh_key_exchange->get_secret()
 					, reinterpret_cast<std::uint8_t*>(buffer.data()), 8);
-				h.update("req1", 4);
+				hasher h(req1);
 				h.update(buffer);
-
 				m_sync_hash.reset(new sha1_hash(h.final()));
 			}
 

src/create_torrent.cpp

@@ -570,7 +570,7 @@ namespace libtorrent
 
 				std::string split = split_path(m_files.symlink(0));
 				for (char const* e = split.c_str(); e != nullptr; e = next_path_element(e))
-					sympath_e.list().push_back(entry(e));
+					sympath_e.list().push_back(e);
 			}
 			if (!m_filehashes.empty())
 			{

src/kademlia/dht_storage.cpp

@@ -85,27 +85,13 @@ namespace
 		std::set<peer_entry> peers;
 	};
 
-#ifndef TORRENT_NO_DEPRECATE
-	struct count_peers
-	{
-		int* count;
-		explicit count_peers(int* c): count(c) {}
-		void operator()(std::pair<libtorrent::sha1_hash
-			, torrent_entry> const& t)
-		{
-			*count += int(t.second.peers.size());
-		}
-	};
-#endif
-
 	// TODO: 2 make this configurable in dht_settings
 	enum { announce_interval = 30 };
 
 	struct dht_immutable_item
 	{
-		dht_immutable_item() : value(nullptr), num_announcers(0), size(0) {}
+		// the actual value
-		// malloced space for the actual value
+		std::unique_ptr<char[]> value;
-		char* value;
 		// this counts the number of IPs we have seen
 		// announcing this item, this is used to determine
 		// popularity if we reach the limit of items to store
@@ -113,20 +99,17 @@ namespace
 		// the last time we heard about this
 		time_point last_seen;
 		// number of IPs in the bloom filter
-		int num_announcers;
+		int num_announcers = 0;
 		// size of malloced space pointed to by value
-		int size;
+		int size = 0;
 	};
 
-	struct ed25519_public_key { char bytes[item_pk_len]; };
-
 	struct dht_mutable_item : dht_immutable_item
 	{
-		char sig[item_sig_len];
+		signature sig;
-		std::int64_t seq;
+		sequence_number seq;
-		ed25519_public_key key;
+		public_key key;
-		char* salt;
+		std::string salt;
-		int salt_size;
 	};
 
 	void touch_item(dht_immutable_item* f, address const& address)
@@ -150,11 +133,12 @@ namespace
 		explicit immutable_item_comparator(std::vector<node_id> const& node_ids) : m_node_ids(node_ids) {}
 		immutable_item_comparator(immutable_item_comparator const&) = default;
 
-		bool operator() (std::pair<node_id, dht_immutable_item> const& lhs
+		template <typename Item>
-			, std::pair<node_id, dht_immutable_item> const& rhs) const
+		bool operator()(std::pair<node_id const, Item> const& lhs
+			, std::pair<node_id const, Item> const& rhs) const
 		{
-			int l_distance = min_distance_exp(lhs.first, m_node_ids);
+			int const l_distance = min_distance_exp(lhs.first, m_node_ids);
-			int r_distance = min_distance_exp(rhs.first, m_node_ids);
+			int const r_distance = min_distance_exp(rhs.first, m_node_ids);
 
 			// this is a score taking the popularity (number of announcers) and the
 			// fit, in terms of distance from ideal storing node, into account.
@@ -180,16 +164,15 @@ namespace
 	typename std::map<node_id, Item>::const_iterator pick_least_important_item(
 		std::vector<node_id> const& node_ids, std::map<node_id, Item> const& table)
 	{
-		return std::min_element(table.begin()
+		return std::min_element(table.begin(), table.end()
-			, table.end()
 			, immutable_item_comparator(node_ids));
 	}
 
 	class dht_default_storage final : public dht_storage_interface, boost::noncopyable
 	{
-	typedef std::map<node_id, torrent_entry> table_t;
+		using table_t = std::map<node_id, torrent_entry>;
-	typedef std::map<node_id, dht_immutable_item> dht_immutable_table_t;
+		using dht_immutable_table_t = std::map<node_id, dht_immutable_item>;
-	typedef std::map<node_id, dht_mutable_item> dht_mutable_table_t;
+		using dht_mutable_table_t = std::map<node_id, dht_mutable_item>;
 
 	public:
 
@@ -205,8 +188,9 @@ namespace
 		size_t num_torrents() const override { return m_map.size(); }
 		size_t num_peers() const override
 		{
-			int ret = 0;
+			size_t ret = 0;
-			std::for_each(m_map.begin(), m_map.end(), count_peers(&ret));
+			for (auto const& t : m_map)
+				ret += t.second.peers.size();
 			return ret;
 		}
 #endif
@@ -216,7 +200,7 @@ namespace
 		}
 
 		bool get_peers(sha1_hash const& info_hash
-			, bool noseed, bool scrape
+			, bool const noseed, bool const scrape
 			, entry& peers) const override
 		{
 			table_t::const_iterator i = m_map.lower_bound(info_hash);
@@ -275,7 +259,7 @@ namespace
 
 		void announce_peer(sha1_hash const& info_hash
 			, tcp::endpoint const& endp
-			, std::string const& name, bool seed) override
+			, std::string const& name, bool const seed) override
 		{
 			table_t::iterator ti = m_map.find(info_hash);
 			torrent_entry* v;
@@ -348,12 +332,13 @@ namespace
 			dht_immutable_table_t::const_iterator i = m_immutable_table.find(target);
 			if (i == m_immutable_table.end()) return false;
 
-			item["v"] = bdecode(i->second.value, i->second.value + i->second.size);
+			item["v"] = bdecode(i->second.value.get()
+				, i->second.value.get() + i->second.size);
 			return true;
 		}
 
 		void put_immutable_item(sha1_hash const& target
-			, char const* buf, int size
+			, span<char const> buf
 			, address const& addr) override
 		{
 			TORRENT_ASSERT(!m_node_ids.empty());
@@ -367,17 +352,16 @@ namespace
 						, m_immutable_table);
 
 					TORRENT_ASSERT(j != m_immutable_table.end());
-					free(j->second.value);
 					m_immutable_table.erase(j);
 					m_counters.immutable_data -= 1;
 				}
 				dht_immutable_item to_add;
-				to_add.value = static_cast<char*>(malloc(size));
+				to_add.value.reset(new char[buf.size()]);
-				to_add.size = size;
+				to_add.size = int(buf.size());
-				memcpy(to_add.value, buf, size);
+				memcpy(to_add.value.get(), buf.data(), buf.size());
 
 				std::tie(i, std::ignore) = m_immutable_table.insert(
-					std::make_pair(target, to_add));
+					std::make_pair(target, std::move(to_add)));
 				m_counters.immutable_data += 1;
 			}
 
@@ -387,7 +371,7 @@ namespace
 		}
 
 		bool get_mutable_item_seq(sha1_hash const& target
-			, std::int64_t& seq) const override
+			, sequence_number& seq) const override
 		{
 			dht_mutable_table_t::const_iterator i = m_mutable_table.find(target);
 			if (i == m_mutable_table.end()) return false;
@@ -397,29 +381,29 @@ namespace
 		}
 
 		bool get_mutable_item(sha1_hash const& target
-			, std::int64_t seq, bool force_fill
+			, sequence_number seq, bool force_fill
 			, entry& item) const override
 		{
 			dht_mutable_table_t::const_iterator i = m_mutable_table.find(target);
 			if (i == m_mutable_table.end()) return false;
 
 			dht_mutable_item const& f = i->second;
-			item["seq"] = f.seq;
+			item["seq"] = f.seq.value;
-			if (force_fill || (0 <= seq && seq < f.seq))
+			if (force_fill || (sequence_number(0) <= seq && seq < f.seq))
 			{
-				item["v"] = bdecode(f.value, f.value + f.size);
+				item["v"] = bdecode(f.value.get(), f.value.get() + f.size);
-				item["sig"] = std::string(f.sig, f.sig + sizeof(f.sig));
+				item["sig"] = f.sig.bytes;
-				item["k"] = std::string(f.key.bytes, f.key.bytes + sizeof(f.key.bytes));
+				item["k"] = f.key.bytes;
 			}
 			return true;
 		}
 
 		void put_mutable_item(sha1_hash const& target
-			, char const* buf, int size
+			, span<char const> buf
-			, char const* sig
+			, signature const& sig
-			, std::int64_t seq
+			, sequence_number seq
-			, char const* pk
+			, public_key const& pk
-			, char const* salt, int salt_size
+			, span<char const> salt
 			, address const& addr) override
 		{
 			TORRENT_ASSERT(!m_node_ids.empty());
@@ -434,47 +418,37 @@ namespace
 						, m_mutable_table);
 
 					TORRENT_ASSERT(j != m_mutable_table.end());
-					free(j->second.value);
-					free(j->second.salt);
 					m_mutable_table.erase(j);
 					m_counters.mutable_data -= 1;
 				}
 				dht_mutable_item to_add;
-				to_add.value = static_cast<char*>(malloc(size));
+				to_add.value.reset(new char[buf.size()]);
-				to_add.size = size;
+				to_add.size = int(buf.size());
 				to_add.seq = seq;
-				to_add.salt = nullptr;
+				to_add.salt.assign(salt.data(), salt.size());
-				to_add.salt_size = 0;
+				to_add.sig = sig;
-				if (salt_size > 0)
+				to_add.key = pk;
-				{
+				memcpy(to_add.value.get(), buf.data(), buf.size());
-					to_add.salt = static_cast<char*>(malloc(salt_size));
-					to_add.salt_size = salt_size;
-					memcpy(to_add.salt, salt, salt_size);
-				}
-				memcpy(to_add.sig, sig, sizeof(to_add.sig));
-				memcpy(to_add.value, buf, size);
-				memcpy(&to_add.key, pk, sizeof(to_add.key));
 
 				std::tie(i, std::ignore) = m_mutable_table.insert(
-					std::make_pair(target, to_add));
+					std::make_pair(target, std::move(to_add)));
 				m_counters.mutable_data += 1;
 			}
 			else
 			{
 				// this is the case where we already
-				dht_mutable_item* item = &i->second;
+				dht_mutable_item& item = i->second;
 
-				if (item->seq < seq)
+				if (item.seq < seq)
 				{
-					if (item->size != size)
+					if (item.size != buf.size())
 					{
-						free(item->value);
+						item.value.reset(new char[buf.size()]);
-						item->value = static_cast<char*>(malloc(size));
+						item.size = int(buf.size());
-						item->size = size;
 					}
-					item->seq = seq;
+					item.seq = seq;
-					memcpy(item->sig, sig, sizeof(item->sig));
+					item.sig = sig;
-					memcpy(item->value, buf, size);
+					memcpy(item.value.get(), buf.data(), buf.size());
 				}
 			}
 
@@ -516,7 +490,6 @@ namespace
 					++i;
 					continue;
 				}
-				free(i->second.value);
 				m_immutable_table.erase(i++);
 				m_counters.immutable_data -= 1;
 			}
@@ -529,8 +502,6 @@ namespace
 					++i;
 					continue;
 				}
-				free(i->second.value);
-				free(i->second.salt);
 				m_mutable_table.erase(i++);
 				m_counters.mutable_data -= 1;
 			}
@@ -556,7 +527,7 @@ namespace
 				, end(peers.end()); i != end;)
 			{
 				// the peer has timed out
-				if (i->added + minutes(int(announce_interval * 1.5f)) < aux::time_now())
+				if (i->added + minutes(int(announce_interval * 3 / 2)) < aux::time_now())
 				{
 					peers.erase(i++);
 					m_counters.peers -= 1;

src/kademlia/dht_tracker.cpp

@@ -444,7 +444,7 @@ namespace libtorrent { namespace dht
 
 	// key is a 32-byte binary string, the public key to look up.
 	// the salt is optional
-	void dht_tracker::get_item(char const* key
+	void dht_tracker::get_item(public_key const& key
 		, boost::function<void(item const&, bool)> cb
 		, std::string salt)
 	{
@@ -461,8 +461,7 @@ namespace libtorrent { namespace dht
 	{
 		std::string flat_data;
 		bencode(std::back_inserter(flat_data), data);
-		sha1_hash target = item_target_id(
+		sha1_hash const target = item_target_id(flat_data);
-			std::pair<char const*, int>(flat_data.c_str(), flat_data.size()));
 
 		boost::shared_ptr<put_item_ctx>
 			ctx = boost::make_shared<put_item_ctx>((TORRENT_USE_IPV6) ? 2 : 1);
@@ -474,7 +473,7 @@ namespace libtorrent { namespace dht
 #endif
 	}
 
-	void dht_tracker::put_item(char const* key
+	void dht_tracker::put_item(public_key const& key
 		, boost::function<void(item const&, int)> cb
 		, boost::function<void(item&)> data_cb, std::string salt)
 	{

src/kademlia/get_item.cpp

@@ -45,9 +45,9 @@ namespace libtorrent { namespace dht
 {
 
 void get_item::got_data(bdecode_node const& v,
-	char const* pk,
+	public_key const& pk,
-	std::uint64_t seq,
+	sequence_number const seq,
-	char const* sig)
+	signature const& sig)
 {
 	// we received data!
 	// if no data_callback, we needn't care about the data we get.
@@ -74,13 +74,11 @@ void get_item::got_data(bdecode_node const& v,
 		return;
 	}
 
-	// immutalbe data should has been handled before this line, only mutable
+	// immutable data should have been handled before this line, only mutable
-	// data can reach here, which means pk and sig must be valid.
+	// data can reach here, which means pk, sig and seq must be valid.
-	if (!pk || !sig) return;
 
-	std::string temp_copy(m_data.salt());
+	std::string const salt_copy(m_data.salt());
-	std::pair<char const*, int> salt(temp_copy.c_str(), int(temp_copy.size()));
+	sha1_hash const incoming_target = item_target_id(salt_copy, pk);
-	sha1_hash incoming_target = item_target_id(salt, pk);
 	if (incoming_target != m_target) return;
 
 	// this is mutable data. If it passes the signature
@@ -88,7 +86,7 @@ void get_item::got_data(bdecode_node const& v,
 	// the highest sequence number.
 	if (m_data.empty() || m_data.seq() < seq)
 	{
-		if (!m_data.assign(v, salt, seq, pk, sig))
+		if (!m_data.assign(v, salt_copy, seq, pk, sig))
 			return;
 
 		// for get_item, we should call callback when we get data,
@@ -114,13 +112,11 @@ get_item::get_item(
 
 get_item::get_item(
 	node& dht_node
-	, char const* pk
+	, public_key const& pk
-	, std::string const& salt
+	, span<char const> salt
 	, data_callback const& dcallback
 	, nodes_callback const& ncallback)
-	: find_data(dht_node, item_target_id(
+	: find_data(dht_node, item_target_id(salt, pk), ncallback)
-		std::make_pair(salt.c_str(), int(salt.size())), pk)
-		, ncallback)
 	, m_data_callback(dcallback)
 	, m_data(pk, salt)
 	, m_immutable(false)
@@ -172,10 +168,7 @@ void get_item::done()
 #if TORRENT_USE_ASSERTS
 		if (m_data.is_mutable())
 		{
-			TORRENT_ASSERT(m_target
+			TORRENT_ASSERT(m_target == item_target_id(m_data.salt(), m_data.pk()));
-				== item_target_id(std::pair<char const*, int>(m_data.salt().c_str()
-					, m_data.salt().size())
-					, m_data.pk().data()));
 		}
 #endif
 	}
@@ -185,9 +178,9 @@ void get_item::done()
 
 void get_item_observer::reply(msg const& m)
 {
-	char const* pk = nullptr;
+	public_key pk;
-	char const* sig = nullptr;
+	signature sig;
-	std::uint64_t seq = 0;
+	sequence_number seq{0};
 
 	bdecode_node r = m.message.dict_find_dict("r");
 	if (!r)
@@ -201,17 +194,19 @@ void get_item_observer::reply(msg const& m)
 	}
 
 	bdecode_node k = r.dict_find_string("k");
-	if (k && k.string_length() == item_pk_len)
+	if (k && k.string_length() == public_key::len)
-		pk = k.string_ptr();
+		std::memcpy(pk.bytes.data(), k.string_ptr(), public_key::len);
 
 	bdecode_node s = r.dict_find_string("sig");
-	if (s && s.string_length() == item_sig_len)
+	if (s && s.string_length() == signature::len)
-		sig = s.string_ptr();
+		std::memcpy(sig.bytes.data(), s.string_ptr(), signature::len);
 
 	bdecode_node q = r.dict_find_int("seq");
 	if (q)
-		seq = q.int_value();
+	{
-	else if (pk && sig)
+		seq = sequence_number(q.int_value());
+	}
+	else if (k && s)
 	{
 		timeout();
 		return;

src/kademlia/item.cpp

@@ -33,10 +33,12 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <libtorrent/hasher.hpp>
 #include <libtorrent/kademlia/item.hpp>
 #include <libtorrent/bencode.hpp>
+#include <libtorrent/span.hpp>
 #include <libtorrent/ed25519.hpp>
 
 #include <cstdio> // for snprintf
 #include <cinttypes> // for PRId64 et.al.
+#include <cstring> // for memcpy
 
 #if TORRENT_USE_ASSERTS
 #include "libtorrent/bdecode.hpp"
@@ -47,67 +49,67 @@ namespace libtorrent { namespace dht
 
 namespace
 {
-	enum { canonical_length = 1200 };
+	int canonical_string(span<char const> v
-	int canonical_string(std::pair<char const*, int> v, std::uint64_t seq
+		, sequence_number const seq
-		, std::pair<char const*, int> salt, char out[canonical_length])
+		, span<char const> salt
+		, span<char> out)
 	{
 		// v must be valid bencoding!
 #if TORRENT_USE_ASSERTS
 		bdecode_node e;
 		error_code ec;
-		TORRENT_ASSERT(bdecode(v.first, v.first + v.second, e, ec) == 0);
+		TORRENT_ASSERT(bdecode(v.data(), v.data() + v.size(), e, ec) == 0);
 #endif
-		char* ptr = out;
+		char* ptr = out.data();
 
-		int left = canonical_length - (ptr - out);
+		size_t left = out.size() - (ptr - out.data());
-		if (salt.second > 0)
+		if (salt.size() > 0)
 		{
-			ptr += std::snprintf(ptr, left, "4:salt%d:", salt.second);
+			ptr += std::snprintf(ptr, left, "4:salt%d:", int(salt.size()));
-			left = canonical_length - (ptr - out);
+			left = out.size() - (ptr - out.data());
-			memcpy(ptr, salt.first, (std::min)(salt.second, left));
+			std::memcpy(ptr, salt.data(), (std::min)(salt.size(), left));
-			ptr += (std::min)(salt.second, left);
+			ptr += (std::min)(salt.size(), left);
-			left = canonical_length - (ptr - out);
+			left = out.size() - (ptr - out.data());
 		}
-		ptr += std::snprintf(ptr, canonical_length - (ptr - out)
+		ptr += std::snprintf(ptr, out.size() - (ptr - out.data())
-			, "3:seqi%" PRId64 "e1:v", seq);
+			, "3:seqi%" PRId64 "e1:v", seq.value);
-		left = canonical_length - (ptr - out);
+		left = out.size() - (ptr - out.data());
-		memcpy(ptr, v.first, (std::min)(v.second, left));
+		std::memcpy(ptr, v.data(), (std::min)(v.size(), left));
-		ptr += (std::min)(v.second, left);
+		ptr += (std::min)(v.size(), left);
-		TORRENT_ASSERT((ptr - out) <= canonical_length);
+		TORRENT_ASSERT((ptr - out.data()) <= out.size());
-		return ptr - out;
+		return ptr - out.data();
 	}
 }
 
 // calculate the target hash for an immutable item.
-sha1_hash item_target_id(std::pair<char const*, int> v)
+sha1_hash item_target_id(span<char const> v)
 {
-	return hasher(v.first, v.second).final();
+	return hasher(v).final();
 }
 
 // calculate the target hash for a mutable item.
-sha1_hash item_target_id(std::pair<char const*, int> salt
+sha1_hash item_target_id(span<char const> salt
-	, char const* pk)
+	, public_key const& pk)
 {
-	hasher h;
+	hasher h(pk.bytes);
-	h.update(pk, item_pk_len);
+	if (salt.size() > 0) h.update(salt);
-	if (salt.second > 0) h.update(salt.first, salt.second);
 	return h.final();
 }
 
 bool verify_mutable_item(
-	std::pair<char const*, int> v
+	span<char const> v
-	, std::pair<char const*, int> salt
+	, span<char const> salt
-	, std::uint64_t seq
+	, sequence_number const seq
-	, char const* pk
+	, public_key const& pk
-	, char const* sig)
+	, signature const& sig)
 {
-	char str[canonical_length];
+	char str[1200];
 	int len = canonical_string(v, seq, salt, str);
 
-	return ed25519_verify(reinterpret_cast<unsigned char const*>(sig)
+	return ed25519_verify(reinterpret_cast<unsigned char const*>(sig.bytes.data())
 		, reinterpret_cast<unsigned char const*>(str)
 		, len
-		, reinterpret_cast<unsigned char const*>(pk)) == 1;
+		, reinterpret_cast<unsigned char const*>(pk.bytes.data())) == 1;
 }
 
 // given the bencoded buffer ``v``, the salt (which is optional and may have
@@ -117,104 +119,107 @@ bool verify_mutable_item(
 // at least 64 bytes of available space. This space is where the signature is
 // written.
 void sign_mutable_item(
-	std::pair<char const*, int> v
+	span<char const> v
-	, std::pair<char const*, int> salt
+	, span<char const> salt
-	, std::uint64_t seq
+	, sequence_number const seq
-	, char const* pk
+	, public_key const& pk
-	, char const* sk
+	, secret_key const& sk
-	, char* sig)
+	, signature& sig)
 {
-	char str[canonical_length];
+	char str[1200];
-	int len = canonical_string(v, seq, salt, str);
+	int const len = canonical_string(v, seq, salt, str);
 
-	ed25519_sign(reinterpret_cast<unsigned char*>(sig)
+	ed25519_sign(reinterpret_cast<unsigned char*>(sig.bytes.data())
 		, reinterpret_cast<unsigned char const*>(str)
 		, len
-		, reinterpret_cast<unsigned char const*>(pk)
+		, reinterpret_cast<unsigned char const*>(pk.bytes.data())
-		, reinterpret_cast<unsigned char const*>(sk)
+		, reinterpret_cast<unsigned char const*>(sk.bytes.data())
 	);
 }
 
-item::item(char const* pk, std::string const& salt)
+item::item(public_key const& pk, span<char const> salt)
-	: m_salt(salt)
+	: m_salt(salt.data(), salt.size())
+	, m_pk(pk)
 	, m_seq(0)
 	, m_mutable(true)
+{}
+
+item::item(entry v)
+	: m_value(std::move(v))
+	, m_seq(0)
+	, m_mutable(false)
+{}
+
+item::item(bdecode_node const& v)
+	: m_value(std::move(v))
+	, m_seq(0)
+	, m_mutable(false)
+{}
+
+item::item(entry v, span<char const> salt
+	, sequence_number const seq, public_key const& pk, secret_key const& sk)
 {
-	memcpy(m_pk.data(), pk, item_pk_len);
+	assign(std::move(v), salt, seq, pk, sk);
 }
 
-item::item(entry const& v
+void item::assign(entry v)
-	, std::pair<char const*, int> salt
-	, std::uint64_t seq, char const* pk, char const* sk)
 {
-	assign(v, salt, seq, pk, sk);
+	m_mutable = false;
+	m_value = std::move(v);
 }
 
-void item::assign(entry const& v, std::pair<char const*, int> salt
+void item::assign(entry v, span<char const> salt
-	, std::uint64_t seq, char const* pk, char const* sk)
+	, sequence_number const seq, public_key const& pk, secret_key const& sk)
 {
+	char buffer[1000];
+	int bsize = bencode(buffer, v);
+	TORRENT_ASSERT(bsize <= 1000);
+	sign_mutable_item(span<char const>(buffer, bsize)
+		, salt, seq, pk, sk, m_sig);
+	m_salt.assign(salt.data(), salt.size());
+	m_pk = pk;
+	m_seq = seq;
+	m_mutable = true;
+	m_value = std::move(v);
+}
+
+void item::assign(bdecode_node const& v)
+{
+	m_mutable = false;
 	m_value = v;
-	if (pk && sk)
-	{
-		char buffer[1000];
-		int bsize = bencode(buffer, v);
-		TORRENT_ASSERT(bsize <= 1000);
-		sign_mutable_item(std::make_pair(buffer, bsize)
-			, salt, seq, pk, sk, m_sig.data());
-		m_salt.assign(salt.first, salt.second);
-		memcpy(m_pk.data(), pk, item_pk_len);
-		m_seq = seq;
-		m_mutable = true;
-	}
-	else
-		m_mutable = false;
 }
 
-bool item::assign(bdecode_node const& v
+bool item::assign(bdecode_node const& v, span<char const> salt
-	, std::pair<char const*, int> salt
+	, sequence_number const seq, public_key const& pk, signature const& sig)
-	, std::uint64_t seq, char const* pk, char const* sig)
 {
-	TORRENT_ASSERT(v.data_section().second <= 1000);
+	TORRENT_ASSERT(v.data_section().size() <= 1000);
-	if (pk && sig)
+	if (!verify_mutable_item(v.data_section(), salt, seq, pk, sig))
-	{
+		return false;
-		if (!verify_mutable_item(v.data_section(), salt, seq, pk, sig))
+	m_pk = pk;
-			return false;
+	m_sig = sig;
-		memcpy(m_pk.data(), pk, item_pk_len);
+	if (salt.size() > 0)
-		memcpy(m_sig.data(), sig, item_sig_len);
+		m_salt.assign(salt.data(), salt.size());
-		if (salt.second > 0)
-			m_salt.assign(salt.first, salt.second);
-		else
-			m_salt.clear();
-		m_seq = seq;
-		m_mutable = true;
-	}
 	else
-		m_mutable = false;
+		m_salt.clear();
+	m_seq = seq;
+	m_mutable = true;
 
 	m_value = v;
 	return true;
 }
 
-void item::assign(entry const& v, std::string salt, std::uint64_t seq
+void item::assign(entry v, span<char const> salt
-	, char const* pk, char const* sig)
+	, sequence_number const seq
+	, public_key const& pk, signature const& sig)
 {
-#if TORRENT_USE_ASSERTS
-	TORRENT_ASSERT(pk && sig);
-	char buffer[1000];
-	int bsize = bencode(buffer, v);
-	TORRENT_ASSERT(bsize <= 1000);
-	TORRENT_ASSERT(verify_mutable_item(
-		std::make_pair(buffer, bsize)
-		, std::make_pair(salt.data(), int(salt.size()))
-		, seq, pk, sig));
-#endif
 
-	memcpy(m_pk.data(), pk, item_pk_len);
+	m_pk = pk;
-	memcpy(m_sig.data(), sig, item_sig_len);
+	m_sig = sig;
-	m_salt = salt;
+	m_salt.assign(salt.data(), salt.size());
 	m_seq = seq;
 	m_mutable = true;
-	m_value = v;
+	m_value = std::move(v);
 }
 
 } } // namespace libtorrent::dht
+

src/kademlia/node.cpp

@@ -145,7 +145,7 @@ void node::update_node_id()
 	m_table.update_node_id(m_id);
 }
 
-bool node::verify_token(std::string const& token, char const* info_hash
+bool node::verify_token(std::string const& token, sha1_hash const& info_hash
 	, udp::endpoint const& addr) const
 {
 	if (token.length() != 4)
@@ -166,7 +166,7 @@ bool node::verify_token(std::string const& token, char const* info_hash
 	if (ec) return false;
 	h1.update(address);
 	h1.update(reinterpret_cast<char const*>(&m_secret[0]), sizeof(m_secret[0]));
-	h1.update(info_hash, 20);
+	h1.update(info_hash);
 
 	sha1_hash h = h1.final();
 	if (std::equal(token.begin(), token.end(), reinterpret_cast<char*>(&h[0])))
@@ -175,7 +175,7 @@ bool node::verify_token(std::string const& token, char const* info_hash
 	hasher h2;
 	h2.update(address);
 	h2.update(reinterpret_cast<char const*>(&m_secret[1]), sizeof(m_secret[1]));
-	h2.update(info_hash, 20);
+	h2.update(info_hash);
 	h = h2.final();
 	if (std::equal(token.begin(), token.end(), reinterpret_cast<char*>(&h[0])))
 		return true;
@@ -183,7 +183,7 @@ bool node::verify_token(std::string const& token, char const* info_hash
 }
 
 std::string node::generate_token(udp::endpoint const& addr
-	, char const* info_hash)
+	, sha1_hash const& info_hash)
 {
 	std::string token;
 	token.resize(4);
@@ -193,7 +193,7 @@ std::string node::generate_token(udp::endpoint const& addr
 	TORRENT_ASSERT(!ec);
 	h.update(address);
 	h.update(reinterpret_cast<char*>(&m_secret[0]), sizeof(m_secret[0]));
-	h.update(info_hash, 20);
+	h.update(info_hash);
 
 	sha1_hash const hash = h.final();
 	std::copy(hash.begin(), hash.begin() + 4, reinterpret_cast<char*>(&token[0]));
@@ -360,7 +360,7 @@ namespace
 		if (node.observer())
 		{
 			char hex_ih[41];
-			aux::to_hex(reinterpret_cast<char const*>(&ih[0]), 20, hex_ih);
+			aux::to_hex(ih.data(), 20, hex_ih);
 			node.observer()->log(dht_logger::node, "sending announce_peer [ ih: %s "
 				" p: %d nodes: %d ]", hex_ih, listen_port, int(v.size()));
 		}
@@ -391,7 +391,7 @@ namespace
 			e["y"] = "q";
 			e["q"] = "announce_peer";
 			entry& a = e["a"];
-			a["info_hash"] = ih.to_string();
+			a["info_hash"] = ih;
 			a["port"] = listen_port;
 			a["token"] = i->second;
 			a["seed"] = (flags & node::flag_seed) ? 1 : 0;
@@ -450,7 +450,7 @@ void node::announce(sha1_hash const& info_hash, int listen_port, int flags
 	if (m_observer)
 	{
 		char hex_ih[41];
-		aux::to_hex(reinterpret_cast<char const*>(&info_hash[0]), 20, hex_ih);
+		aux::to_hex(info_hash.data(), 20, hex_ih);
 		m_observer->log(dht_logger::node, "announcing [ ih: %s p: %d ]"
 			, hex_ih, listen_port);
 	}
@@ -484,7 +484,7 @@ void node::get_item(sha1_hash const& target
 	if (m_observer)
 	{
 		char hex_target[41];
-		aux::to_hex(reinterpret_cast<char const*>(&target[0]), 20, hex_target);
+		aux::to_hex(target.data(), 20, hex_target);
 		m_observer->log(dht_logger::node, "starting get for [ hash: %s ]"
 			, hex_target);
 	}
@@ -495,14 +495,14 @@ void node::get_item(sha1_hash const& target
 	ta->start();
 }
 
-void node::get_item(char const* pk, std::string const& salt
+void node::get_item(public_key const& pk, std::string const& salt
 	, boost::function<void(item const&, bool)> f)
 {
 #ifndef TORRENT_DISABLE_LOGGING
 	if (m_observer)
 	{
 		char hex_key[65];
-		aux::to_hex(pk, 32, hex_key);
+		aux::to_hex(pk.bytes.data(), 32, hex_key);
 		m_observer->log(dht_logger::node, "starting get for [ key: %s ]", hex_key);
 	}
 #endif
@@ -559,7 +559,7 @@ void node::put_item(sha1_hash const& target, entry const& data, boost::function<
 	ta->start();
 }
 
-void node::put_item(char const* pk, std::string const& salt
+void node::put_item(public_key const& pk, std::string const& salt
 	, boost::function<void(item const&, int)> f
 	, boost::function<void(item&)> data_cb)
 {
@@ -567,7 +567,7 @@ void node::put_item(char const* pk, std::string const& salt
 	if (m_observer)
 	{
 		char hex_key[65];
-		aux::to_hex(pk, 32, hex_key);
+		aux::to_hex(pk.bytes.data(), 32, hex_key);
 		m_observer->log(dht_logger::node, "starting get for [ key: %s ]", hex_key);
 	}
 	#endif
@@ -866,7 +866,7 @@ void node::incoming_request(msg const& m, entry& e)
 			return;
 		}
 
-		reply["token"] = generate_token(m.addr, msg_keys[0].string_ptr());
+		reply["token"] = generate_token(m.addr, sha1_hash(msg_keys[0].string_ptr()));
 
 		m_counters.inc_stats_counter(counters::dht_get_peers_in);
 
@@ -944,7 +944,8 @@ void node::incoming_request(msg const& m, entry& e)
 		if (m_observer)
 			m_observer->announce(info_hash, m.addr.address(), port);
 
-		if (!verify_token(msg_keys[2].string_value(), msg_keys[0].string_ptr(), m.addr))
+		if (!verify_token(msg_keys[2].string_value()
+			, sha1_hash(msg_keys[0].string_ptr()), m.addr))
 		{
 			m_counters.inc_stats_counter(counters::dht_invalid_announce);
 			incoming_error(e, "invalid token");
@@ -973,8 +974,8 @@ void node::incoming_request(msg const& m, entry& e)
 			{"v", bdecode_node::none_t, 0, 0},
 			{"seq", bdecode_node::int_t, 0, key_desc_t::optional},
 			// public key
-			{"k", bdecode_node::string_t, item_pk_len, key_desc_t::optional},
+			{"k", bdecode_node::string_t, public_key::len, key_desc_t::optional},
-			{"sig", bdecode_node::string_t, item_sig_len, key_desc_t::optional},
+			{"sig", bdecode_node::string_t, signature::len, key_desc_t::optional},
 			{"cas", bdecode_node::int_t, 0, key_desc_t::optional},
 			{"salt", bdecode_node::string_t, 0, key_desc_t::optional},
 		};
@@ -994,38 +995,35 @@ void node::incoming_request(msg const& m, entry& e)
 		bool mutable_put = (msg_keys[2] && msg_keys[3] && msg_keys[4]);
 
 		// public key (only set if it's a mutable put)
-		char const* pk = nullptr;
+		char const* pub_key = nullptr;
-		if (msg_keys[3]) pk = msg_keys[3].string_ptr();
+		if (msg_keys[3]) pub_key = msg_keys[3].string_ptr();
 
 		// signature (only set if it's a mutable put)
-		char const* sig = nullptr;
+		char const* sign = nullptr;
-		if (msg_keys[4]) sig = msg_keys[4].string_ptr();
+		if (msg_keys[4]) sign = msg_keys[4].string_ptr();
 
 		// pointer and length to the whole entry
-		std::pair<char const*, int> buf = msg_keys[1].data_section();
+		span<char const> buf = msg_keys[1].data_section();
-		if (buf.second > 1000 || buf.second <= 0)
+		if (buf.size() > 1000 || buf.size() <= 0)
 		{
 			m_counters.inc_stats_counter(counters::dht_invalid_put);
 			incoming_error(e, "message too big", 205);
 			return;
 		}
 
-		std::pair<char const*, int> salt(static_cast<char const*>(nullptr), 0);
+		span<char const> salt;
 		if (msg_keys[6])
-			salt = std::pair<char const*, int>(
+			salt = { msg_keys[6].string_ptr(), size_t(msg_keys[6].string_length()) };
-				msg_keys[6].string_ptr(), msg_keys[6].string_length());
+		if (salt.size() > 64)
-		if (salt.second > 64)
 		{
 			m_counters.inc_stats_counter(counters::dht_invalid_put);
 			incoming_error(e, "salt too big", 207);
 			return;
 		}
 
-		sha1_hash target;
+		sha1_hash const target = pub_key
-		if (pk)
+			? item_target_id(salt, public_key(pub_key))
-			target = item_target_id(salt, pk);
+			: item_target_id(buf);
-		else
-			target = item_target_id(buf);
 
 //		std::fprintf(stderr, "%s PUT target: %s salt: %s key: %s\n"
 //			, mutable_put ? "mutable":"immutable"
@@ -1035,8 +1033,7 @@ void node::incoming_request(msg const& m, entry& e)
 
 		// verify the write-token. tokens are only valid to write to
 		// specific target hashes. it must match the one we got a "get" for
-		if (!verify_token(msg_keys[0].string_value()
+		if (!verify_token(msg_keys[0].string_value(), target, m.addr))
-				, reinterpret_cast<char const*>(&target[0]), m.addr))
 		{
 			m_counters.inc_stats_counter(counters::dht_invalid_put);
 			incoming_error(e, "invalid token");
@@ -1045,14 +1042,16 @@ void node::incoming_request(msg const& m, entry& e)
 
 		if (!mutable_put)
 		{
-			m_storage.put_immutable_item(target, buf.first, buf.second, m.addr.address());
+			m_storage.put_immutable_item(target, buf, m.addr.address());
 		}
 		else
 		{
 			// mutable put, we must verify the signature
-			std::int64_t const seq = msg_keys[2].int_value();
+			sequence_number const seq(msg_keys[2].int_value());
+			public_key const pk(pub_key);
+			signature const sig(sign);
 
-			if (seq < 0)
+			if (seq < sequence_number(0))
 			{
 				m_counters.inc_stats_counter(counters::dht_invalid_put);
 				incoming_error(e, "invalid (negative) sequence number");
@@ -1060,23 +1059,19 @@ void node::incoming_request(msg const& m, entry& e)
 			}
 
 			// msg_keys[4] is the signature, msg_keys[3] is the public key
-			if (!verify_mutable_item(buf, salt
+			if (!verify_mutable_item(buf, salt, seq, pk, sig))
-				, seq, pk, sig))
 			{
 				m_counters.inc_stats_counter(counters::dht_invalid_put);
 				incoming_error(e, "invalid signature", 206);
 				return;
 			}
 
-			TORRENT_ASSERT(item_sig_len == msg_keys[4].string_length());
+			TORRENT_ASSERT(signature::len == msg_keys[4].string_length());
 
-			std::int64_t item_seq;
+			sequence_number item_seq;
 			if (!m_storage.get_mutable_item_seq(target, item_seq))
 			{
-				m_storage.put_mutable_item(target
+				m_storage.put_mutable_item(target, buf, sig, seq, pk, salt
-					, buf.first, buf.second
-					, sig, seq, pk
-					, salt.first, salt.second
 					, m.addr.address());
 			}
 			else
@@ -1086,7 +1081,7 @@ void node::incoming_request(msg const& m, entry& e)
 				// number matches the expected value before replacing it
 				// this is critical for avoiding race conditions when multiple
 				// writers are accessing the same slot
-				if (msg_keys[5] && item_seq != msg_keys[5].int_value())
+				if (msg_keys[5] && item_seq.value != msg_keys[5].int_value())
 				{
 					m_counters.inc_stats_counter(counters::dht_invalid_put);
 					incoming_error(e, "CAS mismatch", 301);
@@ -1100,10 +1095,7 @@ void node::incoming_request(msg const& m, entry& e)
 					return;
 				}
 
-				m_storage.put_mutable_item(target
+				m_storage.put_mutable_item(target, buf, sig, seq, pk, salt
-					, buf.first, buf.second
-					, sig, seq, pk
-					, salt.first, salt.second
 					, m.addr.address());
 			}
 		}
@@ -1137,7 +1129,7 @@ void node::incoming_request(msg const& m, entry& e)
 //			, msg_keys[1] ? "mutable":"immutable"
 //			, aux::to_hex(target.to_string()).c_str());
 
-		reply["token"] = generate_token(m.addr, msg_keys[1].string_ptr());
+		reply["token"] = generate_token(m.addr, sha1_hash(msg_keys[1].string_ptr()));
 
 		// always return nodes as well as peers
 		write_nodes_entries(target, msg_keys[2], reply);
@@ -1148,13 +1140,14 @@ void node::incoming_request(msg const& m, entry& e)
 		{
 			if (!m_storage.get_immutable_item(target, reply)) // ok, check for a mutable one
 			{
-				m_storage.get_mutable_item(target, 0, true, reply);
+				m_storage.get_mutable_item(target, sequence_number(0)
+					, true, reply);
 			}
 		}
 		else
 		{
 			m_storage.get_mutable_item(target
-				, msg_keys[0].int_value(), false
+				, sequence_number(msg_keys[0].int_value()), false
 				, reply);
 		}
 	}

src/kademlia/put_data.cpp

@@ -106,9 +106,9 @@ bool put_data::invoke(observer_ptr o)
 	a["token"] = po->m_token;
 	if (m_data.is_mutable())
 	{
-		a["k"] = std::string(m_data.pk().data(), item_pk_len);
+		a["k"] = m_data.pk().bytes;
-		a["seq"] = m_data.seq();
+		a["seq"] = m_data.seq().value;
-		a["sig"] = std::string(m_data.sig().data(), item_sig_len);
+		a["sig"] = m_data.sig().bytes;
 		if (!m_data.salt().empty())
 		{
 			a["salt"] = m_data.salt();

src/pe_crypto.cpp

@@ -96,11 +96,9 @@ namespace libtorrent
 		std::array<char, 96> buffer;
 		mp::export_bits(m_dh_shared_secret, reinterpret_cast<std::uint8_t*>(buffer.data()), 8);
 
+		static char const req3[4] = {'r', 'e', 'q', '3'};
 		// calculate the xor mask for the obfuscated hash
-		hasher h;
+		m_xor_mask = hasher(req3).update(buffer).final();
-		h.update("req3", 4);
-		h.update(buffer);
-		m_xor_mask = h.final();
 	}
 
 	std::tuple<int, span<aux::const_buffer>>
@@ -148,7 +146,7 @@ namespace libtorrent
 		if (num_bufs != 0)
 		{
 			std::tie(next_barrier, out_iovec)
-				= m_send_barriers.front().enc_handler->encrypt({bufs, num_bufs});
+				= m_send_barriers.front().enc_handler->encrypt({bufs, size_t(num_bufs)});
 		}
 
 		if (m_send_barriers.front().next != INT_MAX)

src/read_resume_data.cpp

@@ -97,8 +97,7 @@ namespace libtorrent
 		{
 			// verify the info-hash of the metadata stored in the resume file matches
 			// the torrent we're loading
-			sha1_hash const resume_ih = hasher(info.data_section().first
+			sha1_hash const resume_ih = hasher(info.data_section()).final();
-				, info.data_section().second).final();
 
 			// if url is set, the info_hash is not actually the info-hash of the
 			// torrent, but the hash of the URL, until we have the full torrent

src/session_handle.cpp

@@ -521,6 +521,8 @@ namespace libtorrent
 #endif
 	}
 
+	// TODO: 3 expose the sequence_number, public_key, secret_key and signature
+	// types to the client
 	sha1_hash session_handle::dht_put_item(entry data)
 	{
 		std::vector<char> buf;

src/session_impl.cpp

@@ -81,6 +81,7 @@ const rlim_t rlim_infinity = RLIM_INFINITY;
 #include "libtorrent/aux_/session_impl.hpp"
 #ifndef TORRENT_DISABLE_DHT
 #include "libtorrent/kademlia/dht_tracker.hpp"
+#include "libtorrent/kademlia/types.hpp"
 #endif
 #include "libtorrent/enum_net.hpp"
 #include "libtorrent/config.hpp"
@@ -4716,9 +4717,9 @@ namespace aux {
 		TORRENT_ASSERT(m_torrents.size() >= m_torrent_lru.size());
 
 #if !defined(TORRENT_DISABLE_ENCRYPTION) && !defined(TORRENT_DISABLE_EXTENSIONS)
-		hasher h;
+		static char const req2[4] = {'r', 'e', 'q', '2'};
-		h.update("req2", 4);
+		hasher h(req2);
-		h.update(params.info_hash.data(), 20);
+		h.update(params.info_hash);
 		// this is SHA1("req2" + info-hash), used for
 		// encrypted hand shakes
 		m_obfuscated_torrents.insert(std::make_pair(h.final(), torrent_ptr));
@@ -5044,8 +5045,7 @@ namespace aux {
 		if (i == m_torrents.end() && !tptr->url().empty())
 		{
 			std::string const& url = tptr->url();
-			sha1_hash urlhash = hasher(&url[0], int(url.size())).final();
+			i = m_torrents.find(hasher(url).final());
-			i = m_torrents.find(urlhash);
 		}
 #endif
 
@@ -5085,9 +5085,9 @@ namespace aux {
 		TORRENT_ASSERT(m_torrents.size() >= m_torrent_lru.size());
 
 #if !defined(TORRENT_DISABLE_ENCRYPTION) && !defined(TORRENT_DISABLE_EXTENSIONS)
-		hasher h;
+		static char const req2[4] = {'r', 'e', 'q', '2'};
-		h.update("req2", 4);
+		hasher h(req2);
-		h.update(tptr->info_hash().data(), 20);
+		h.update(tptr->info_hash());
 		m_obfuscated_torrents.erase(h.final());
 #endif
 
@@ -5714,20 +5714,23 @@ namespace aux {
 	}
 
 	// callback for dht_mutable_get
-	void session_impl::get_mutable_callback(dht::item const& i, bool authoritative)
+	void session_impl::get_mutable_callback(dht::item const& i
+		, bool const authoritative)
 	{
 		TORRENT_ASSERT(i.is_mutable());
-		m_alerts.emplace_alert<dht_mutable_item_alert>(i.pk(), i.sig(), i.seq()
+		m_alerts.emplace_alert<dht_mutable_item_alert>(i.pk().bytes
+			, i.sig().bytes, i.seq().value
 			, i.salt(), i.value(), authoritative);
 	}
 
 	// key is a 32-byte binary string, the public key to look up.
 	// the salt is optional
+	// TODO: 3 use public_key here instead of std::array
 	void session_impl::dht_get_mutable_item(std::array<char, 32> key
 		, std::string salt)
 	{
 		if (!m_dht) return;
-		m_dht->get_item(key.data(), std::bind(&session_impl::get_mutable_callback
+		m_dht->get_item(dht::public_key(key.data()), std::bind(&session_impl::get_mutable_callback
 			, this, _1, _2), salt);
 	}
 
@@ -5741,26 +5744,29 @@ namespace aux {
 
 		void on_dht_put_mutable_item(alert_manager& alerts, dht::item const& i, int num)
 		{
-			std::array<char, 64> sig = i.sig();
+			dht::signature sig = i.sig();
-			std::array<char, 32> pk = i.pk();
+			dht::public_key pk = i.pk();
-			std::uint64_t seq = i.seq();
+			dht::sequence_number seq = i.seq();
 			std::string salt = i.salt();
 
 			if (alerts.should_post<dht_put_alert>())
-				alerts.emplace_alert<dht_put_alert>(pk, sig, salt, seq, num);
+			{
+				alerts.emplace_alert<dht_put_alert>(pk.bytes, sig.bytes, salt
+					, seq.value, num);
+			}
 		}
 
 		void put_mutable_callback(dht::item& i
-			, boost::function<void(entry&, std::array<char,64>&
+			, boost::function<void(entry&, std::array<char, 64>&
 				, std::uint64_t&, std::string const&)> cb)
 		{
 			entry value = i.value();
-			std::array<char, 64> sig = i.sig();
+			dht::signature sig = i.sig();
-			std::array<char, 32> pk = i.pk();
+			dht::public_key pk = i.pk();
-			std::uint64_t seq = i.seq();
+			dht::sequence_number seq = i.seq();
 			std::string salt = i.salt();
-			cb(value, sig, seq, salt);
+			cb(value, sig.bytes, seq.value, salt);
-			i.assign(value, salt, seq, pk.data(), sig.data());
+			i.assign(std::move(value), salt, seq, pk, sig);
 		}
 
 		void on_dht_get_peers(alert_manager& alerts, sha1_hash info_hash, std::vector<tcp::endpoint> const& peers)
@@ -5792,9 +5798,9 @@ namespace aux {
 		, std::string salt)
 	{
 		if (!m_dht) return;
-		m_dht->put_item(key.data(),
+		m_dht->put_item(dht::public_key(key.data())
-			std::bind(&on_dht_put_mutable_item, boost::ref(m_alerts), _1, _2),
+			, std::bind(&on_dht_put_mutable_item, boost::ref(m_alerts), _1, _2)
-			std::bind(&put_mutable_callback, _1, cb), salt);
+			, std::bind(&put_mutable_callback, _1, cb), salt);
 	}
 
 	void session_impl::dht_get_peers(sha1_hash const& info_hash)

src/smart_ban.cpp

@@ -195,7 +195,7 @@ namespace
 			h.update(j->buffer.disk_block, j->d.io.buffer_size);
 			h.update(reinterpret_cast<char const*>(&m_salt), sizeof(m_salt));
 
-			std::pair<peer_list::iterator, peer_list::iterator> range
+			std::pair<peer_list::iterator, peer_list::iterator> const range
 				= m_torrent.find_peers(a);
 
 			// there is no peer with this address anymore
@@ -270,7 +270,7 @@ namespace
 			hasher h;
 			h.update(j->buffer.disk_block, j->d.io.buffer_size);
 			h.update(reinterpret_cast<char const*>(&m_salt), sizeof(m_salt));
-			sha1_hash ok_digest = h.final();
+			sha1_hash const ok_digest = h.final();
 
 			if (b.second.digest == ok_digest) return;
 

src/torrent.cpp

@@ -537,8 +537,8 @@ namespace libtorrent
 		m_web_seeds.insert(m_web_seeds.end(), web_seeds.begin(), web_seeds.end());
 
 #if !defined(TORRENT_DISABLE_ENCRYPTION) && !defined(TORRENT_DISABLE_EXTENSIONS)
-		hasher h;
+		static char const req2[4] = {'r', 'e', 'q', '2'};
-		h.update("req2", 4);
+		hasher h(req2);
 		h.update(m_torrent_file->info_hash());
 		m_ses.add_obfuscated_hash(h.final(), shared_from_this());
 #endif
@@ -7011,6 +7011,7 @@ namespace libtorrent
 		return peerinfo->connection != nullptr;
 	}
 
+	// TODO: 3 make this take a span<char const> instead
 	bool torrent::set_metadata(char const* metadata_buf, int metadata_size)
 	{
 		TORRENT_ASSERT(is_single_thread());
@@ -7031,7 +7032,8 @@ namespace libtorrent
 
 		bdecode_node metadata;
 		error_code ec;
-		int ret = bdecode(metadata_buf, metadata_buf + metadata_size, metadata, ec);
+		int ret = bdecode(metadata_buf
+			, metadata_buf + metadata_size, metadata, ec);
 		if (ret != 0 || !m_torrent_file->parse_info_section(metadata, ec, 0))
 		{
 			update_gauge();

src/torrent_info.cpp

@@ -1050,28 +1050,25 @@ namespace libtorrent
 		}
 
 		// hash the info-field to calculate info-hash
-		hasher h;
+		auto section = info.data_section();
-		std::pair<char const*, int> section = info.data_section();
+		m_info_hash = hasher(section).final();
-		h.update(section.first, section.second);
+		if (info.data_section().size() >= (std::numeric_limits<std::uint32_t>::max)())
-		m_info_hash = h.final();
-
-		if (section.second >= (std::numeric_limits<std::uint32_t>::max)())
 		{
 			ec = errors::metadata_too_large;
 			return false;
 		}
 
 		// copy the info section
-		m_info_section_size = section.second;
+		m_info_section_size = int(section.size());
 		m_info_section.reset(new char[m_info_section_size]);
-		std::memcpy(m_info_section.get(), section.first, m_info_section_size);
+		std::memcpy(m_info_section.get(), section.data(), m_info_section_size);
-		TORRENT_ASSERT(section.first[0] == 'd');
+		TORRENT_ASSERT(section[0] == 'd');
-		TORRENT_ASSERT(section.first[m_info_section_size-1] == 'e');
+		TORRENT_ASSERT(section[m_info_section_size-1] == 'e');
 
 		// when translating a pointer that points into the 'info' tree's
 		// backing buffer, into a pointer to our copy of the info section,
 		// this is the pointer offset to use.
-		ptrdiff_t info_ptr_diff = m_info_section.get() - section.first;
+		ptrdiff_t const info_ptr_diff = m_info_section.get() - section.data();
 
 		// extract piece length
 		int piece_length = info.dict_find_int_value("piece length", -1);

test/Jamfile

@@ -143,6 +143,7 @@ test-suite libtorrent :
 
 	[ run test_dht.cpp
 		test_dht_storage.cpp
+		test_direct_dht.cpp
 		]
 
 	[ run test_string.cpp
@@ -154,7 +155,6 @@ test-suite libtorrent :
 	[ run test_crc32.cpp ]
 	[ run test_receive_buffer.cpp ]
 	[ run test_alert_manager.cpp ]
-	[ run test_direct_dht.cpp ]
 	[ run test_magnet.cpp ]
 	[ run test_storage.cpp ]
 	[ run test_session.cpp ]

test/test_bdecode.cpp

@@ -42,13 +42,13 @@ TORRENT_TEST(integer)
 	bdecode_node e;
 	error_code ec;
 	int ret = bdecode(b, b + sizeof(b)-1, e, ec);
-	TEST_CHECK(ret == 0);
+	TEST_EQUAL(ret, 0);
 	std::printf("%s\n", print_entry(e).c_str());
-	std::pair<const char*, int> section = e.data_section();
+	span<const char> section = e.data_section();
-	TEST_CHECK(std::memcmp(b, section.first, section.second) == 0);
+	TEST_CHECK(std::memcmp(b, section.data(), section.size()) == 0);
-	TEST_CHECK(section.second == sizeof(b) - 1);
+	TEST_EQUAL(section.size(), sizeof(b) - 1);
-	TEST_CHECK(e.type() == bdecode_node::int_t);
+	TEST_EQUAL(e.type(), bdecode_node::int_t);
-	TEST_CHECK(e.int_value() == 12453);
+	TEST_EQUAL(e.int_value(), 12453);
 }
 
 // test string
@@ -58,11 +58,11 @@ TORRENT_TEST(string)
 	bdecode_node e;
 	error_code ec;
 	int ret = bdecode(b, b + sizeof(b)-1, e, ec);
-	TEST_CHECK(ret == 0);
+	TEST_EQUAL(ret, 0);
 	std::printf("%s\n", print_entry(e).c_str());
-	std::pair<const char*, int> section = e.data_section();
+	span<const char> section = e.data_section();
-	TEST_CHECK(std::memcmp(b, section.first, section.second) == 0);
+	TEST_CHECK(std::memcmp(b, section.data(), section.size()) == 0);
-	TEST_EQUAL(section.second, sizeof(b) - 1);
+	TEST_EQUAL(section.size(), sizeof(b) - 1);
 	TEST_EQUAL(e.type(), bdecode_node::string_t);
 	TEST_EQUAL(e.string_value(), std::string("abcdefghijklmnopqrstuvwxyz"));
 	TEST_EQUAL(e.string_length(), 26);
@@ -79,11 +79,11 @@ TORRENT_TEST(string_prefix1)
 	bdecode_node e;
 	error_code ec;
 	int ret = bdecode(test.c_str(), test.c_str() + test.size(), e, ec);
-	TEST_CHECK(ret == 0);
+	TEST_EQUAL(ret, 0);
 	std::printf("%d bytes string\n", e.string_length());
-	std::pair<const char*, int> section = e.data_section();
+	span<const char> section = e.data_section();
-	TEST_CHECK(std::memcmp(test.c_str(), section.first, section.second) == 0);
+	TEST_CHECK(std::memcmp(test.c_str(), section.data(), section.size()) == 0);
-	TEST_EQUAL(section.second, int(test.size()));
+	TEST_EQUAL(section.size(), test.size());
 	TEST_EQUAL(e.type(), bdecode_node::string_t);
 	TEST_EQUAL(e.string_length(), 1000000);
 	TEST_EQUAL(e.string_ptr(), test.c_str() + 8);
@@ -96,21 +96,21 @@ TORRENT_TEST(list)
 	bdecode_node e;
 	error_code ec;
 	int ret = bdecode(b, b + sizeof(b)-1, e, ec);
-	TEST_CHECK(ret == 0);
+	TEST_EQUAL(ret, 0);
 	std::printf("%s\n", print_entry(e).c_str());
-	std::pair<const char*, int> section = e.data_section();
+	span<const char> section = e.data_section();
-	TEST_CHECK(std::memcmp(b, section.first, section.second) == 0);
+	TEST_CHECK(std::memcmp(b, section.data(), section.size()) == 0);
-	TEST_CHECK(section.second == sizeof(b) - 1);
+	TEST_EQUAL(section.size(), sizeof(b) - 1);
-	TEST_CHECK(e.type() == bdecode_node::list_t);
+	TEST_EQUAL(e.type(), bdecode_node::list_t);
-	TEST_CHECK(e.list_size() == 2);
+	TEST_EQUAL(e.list_size(), 2);
-	TEST_CHECK(e.list_at(0).type() == bdecode_node::int_t);
+	TEST_EQUAL(e.list_at(0).type(), bdecode_node::int_t);
-	TEST_CHECK(e.list_at(1).type() == bdecode_node::string_t);
+	TEST_EQUAL(e.list_at(1).type(), bdecode_node::string_t);
-	TEST_CHECK(e.list_at(0).int_value() == 12453);
+	TEST_EQUAL(e.list_at(0).int_value(), 12453);
-	TEST_CHECK(e.list_at(1).string_value() == std::string("aaa"));
+	TEST_EQUAL(e.list_at(1).string_value(), std::string("aaa"));
-	TEST_CHECK(e.list_at(1).string_length() == 3);
+	TEST_EQUAL(e.list_at(1).string_length(), 3);
 	section = e.list_at(1).data_section();
-	TEST_CHECK(std::memcmp("3:aaa", section.first, section.second) == 0);
+	TEST_CHECK(std::memcmp("3:aaa", section.data(), section.size()) == 0);
-	TEST_CHECK(section.second == 5);
+	TEST_EQUAL(section.size(), 5);
 }
 
 // test dict
@@ -122,20 +122,20 @@ TORRENT_TEST(dict)
 	int ret = bdecode(b, b + sizeof(b)-1, e, ec);
 	TEST_EQUAL(ret, 0);
 	std::printf("%s\n", print_entry(e).c_str());
-	std::pair<const char*, int> section = e.data_section();
+	span<const char> section = e.data_section();
-	TEST_CHECK(std::memcmp(b, section.first, section.second) == 0);
+	TEST_CHECK(std::memcmp(b, section.data(), section.size()) == 0);
-	TEST_CHECK(section.second == sizeof(b) - 1);
+	TEST_EQUAL(section.size(), sizeof(b) - 1);
-	TEST_CHECK(e.type() == bdecode_node::dict_t);
+	TEST_EQUAL(e.type(), bdecode_node::dict_t);
-	TEST_CHECK(e.dict_size() == 4);
+	TEST_EQUAL(e.dict_size(), 4);
-	TEST_CHECK(e.dict_find("a").type() == bdecode_node::int_t);
+	TEST_EQUAL(e.dict_find("a").type(), bdecode_node::int_t);
-	TEST_CHECK(e.dict_find("a").int_value() == 12453);
+	TEST_EQUAL(e.dict_find("a").int_value(), 12453);
-	TEST_CHECK(e.dict_find("b").type() == bdecode_node::string_t);
+	TEST_EQUAL(e.dict_find("b").type(), bdecode_node::string_t);
-	TEST_CHECK(e.dict_find("b").string_value() == std::string("aaa"));
+	TEST_EQUAL(e.dict_find("b").string_value(), std::string("aaa"));
-	TEST_CHECK(e.dict_find("b").string_length() == 3);
+	TEST_EQUAL(e.dict_find("b").string_length(), 3);
-	TEST_CHECK(e.dict_find("c").type() == bdecode_node::string_t);
+	TEST_EQUAL(e.dict_find("c").type(), bdecode_node::string_t);
-	TEST_CHECK(e.dict_find("c").string_value() == std::string("bbb"));
+	TEST_EQUAL(e.dict_find("c").string_value(), std::string("bbb"));
-	TEST_CHECK(e.dict_find("c").string_length() == 3);
+	TEST_EQUAL(e.dict_find("c").string_length(), 3);
-	TEST_CHECK(e.dict_find_string_value("X") == "0123456789");
+	TEST_EQUAL(e.dict_find_string_value("X"), "0123456789");
 }
 
 // test dictionary with a key without a value
@@ -173,7 +173,7 @@ TORRENT_TEST(dict_null_key)
 	bdecode_node e;
 	error_code ec;
 	int ret = bdecode(b, b + sizeof(b)-1, e, ec);
-	TEST_CHECK(ret == 0);
+	TEST_EQUAL(ret, 0);
 	TEST_CHECK(e.dict_size() == 1);
 	bdecode_node d = e.dict_find(std::string("a\0b", 3));
 	TEST_EQUAL(d.type(), bdecode_node::int_t);
@@ -350,7 +350,7 @@ TORRENT_TEST(64bit_int)
 	bdecode_node e;
 	error_code ec;
 	int ret = bdecode(b, b + sizeof(b)-1, e, ec);
-	TEST_CHECK(ret == 0);
+	TEST_EQUAL(ret, 0);
 	std::printf("%s\n", print_entry(e).c_str());
 	TEST_CHECK(e.int_value() == 9223372036854775807LL);
 }
@@ -362,7 +362,7 @@ TORRENT_TEST(64bit_int_negative)
 	bdecode_node e;
 	error_code ec;
 	int ret = bdecode(b, b + sizeof(b)-1, e, ec);
-	TEST_CHECK(ret == 0);
+	TEST_EQUAL(ret, 0);
 	std::printf("%s\n", print_entry(e).c_str());
 	TEST_CHECK(e.int_value() == -9223372036854775807LL);
 }

test/test_dht.cpp

@@ -70,11 +70,21 @@ sha1_hash to_hash(char const* s)
 	return ret;
 }
 
-void get_test_keypair(char* public_key, char* private_key)
+void get_test_keypair(public_key& pk, secret_key& sk)
 {
-	aux::from_hex("77ff84905a91936367c01360803104f92432fcd904a43511876df5cdf3e7e548", 64, public_key);
+	aux::from_hex("77ff84905a91936367c01360803104f92432fcd904a43511876df5cdf3e7e548", 64, pk.bytes.data());
 	aux::from_hex("e06d3183d14159228433ed599221b80bd0a5ce8352e4bdf0262f76786ef1c74d"
-		"b7e7a9fea2c0eb269d61e3b38e450a22e754941ac78479d6c54e1faf6037881d", 128, private_key);
+		"b7e7a9fea2c0eb269d61e3b38e450a22e754941ac78479d6c54e1faf6037881d", 128, sk.bytes.data());
+}
+
+sequence_number prev_seq(sequence_number s)
+{
+	return sequence_number(s.value - 1);
+}
+
+sequence_number next_seq(sequence_number s)
+{
+	return sequence_number(s.value + 1);
 }
 
 void add_and_replace(libtorrent::dht::node_id& dst, libtorrent::dht::node_id const& add)
@@ -163,8 +173,8 @@ struct msg_args
 	msg_args& port(int p)
 	{ a["port"] = p; return *this; }
 
-	msg_args& target(char const* t)
+	msg_args& target(sha1_hash const& t)
-	{ if (t) a["target"] = std::string(t, 20); return *this; }
+	{ a["target"] = t.to_string(); return *this; }
 
 	msg_args& value(entry const& v)
 	{ a["v"] = v; return *this; }
@@ -175,23 +185,23 @@ struct msg_args
 	msg_args& seed(bool s)
 	{ a["seed"] = s ? 1 : 0; return *this; }
 
-	msg_args& key(std::string k)
+	msg_args& key(public_key const& k)
-	{ a["k"] = k; return *this; }
+	{ a["k"] = k.bytes; return *this; }
 
-	msg_args& sig(std::string s)
+	msg_args& sig(signature const& s)
-	{ a["sig"] = s; return *this; }
+	{ a["sig"] = s.bytes; return *this; }
 
-	msg_args& seq(int s)
+	msg_args& seq(sequence_number s)
-	{ a["seq"] = s; return *this; }
+	{ a["seq"] = s.value; return *this; }
 
-	msg_args& cas(std::int64_t c)
+	msg_args& cas(sequence_number c)
-	{ a["cas"] = c; return *this; }
+	{ a["cas"] = c.value; return *this; }
 
 	msg_args& nid(sha1_hash const& n)
 	{ a["id"] = n.to_string(); return *this; }
 
-	msg_args& salt(char const* s)
+	msg_args& salt(span<char const> s)
-	{ if (s) a["salt"] = s; return *this; }
+	{ if (!s.empty()) a["salt"] = s; return *this; }
 
 	msg_args& want(std::string w)
 	{ a["want"].list().push_back(w); return *this; }
@@ -312,7 +322,7 @@ void announce_immutable_items(node& node, udp::endpoint const* eps
 			if ((i % items[j].num_peers) == 0) continue;
 			bdecode_node response;
 			send_dht_request(node, "get", eps[i], &response
-				, msg_args().target((char const*)&items[j].target[0]));
+				, msg_args().target(items[j].target));
 
 			key_desc_t const desc[] =
 			{
@@ -353,7 +363,7 @@ void announce_immutable_items(node& node, udp::endpoint const* eps
 			send_dht_request(node, "put", eps[i], &response
 				, msg_args()
 					.token(token)
-					.target((char const*)&items[j].target[0])
+					.target(items[j].target)
 					.value(items[j].ent));
 
 			key_desc_t const desc2[] =
@@ -385,7 +395,7 @@ void announce_immutable_items(node& node, udp::endpoint const* eps
 	{
 		bdecode_node response;
 		send_dht_request(node, "get", eps[j], &response
-			, msg_args().target((char const*)&items[j].target[0]));
+			, msg_args().target(items[j].target));
 
 		key_desc_t const desc[] =
 		{
@@ -554,9 +564,9 @@ dht::key_desc_t const put_mutable_item_desc[] = {
 	{"a", bdecode_node::dict_t, 0, key_desc_t::parse_children},
 		{"id", bdecode_node::string_t, 20, 0},
 		{"cas", bdecode_node::string_t, 20, key_desc_t::optional},
-		{"k", bdecode_node::string_t, item_pk_len, 0},
+		{"k", bdecode_node::string_t, public_key::len, 0},
 		{"seq", bdecode_node::int_t, 0, 0},
-		{"sig", bdecode_node::string_t, item_sig_len, 0},
+		{"sig", bdecode_node::string_t, signature::len, 0},
 		{"token", bdecode_node::string_t, 2, 0},
 		{"v", bdecode_node::none_t, 0, key_desc_t::last_child},
 };
@@ -820,7 +830,9 @@ void test_id_enforcement(address(&rand_addr)())
 	nid[0] = 0x18;
 	int nodes_num = std::get<0>(t.dht_node.size());
 	send_dht_request(t.dht_node, "find_node", t.source, &response
-		, msg_args().target("0101010101010101010101010101010101010101").nid(nid));
+		, msg_args()
+			.target(sha1_hash("0101010101010101010101010101010101010101"))
+			.nid(nid));
 
 	bdecode_node err_keys[2];
 	bool ret = dht::verify_message(response, err_desc, err_keys, t.error_string
@@ -855,7 +867,9 @@ void test_id_enforcement(address(&rand_addr)())
 	else
 		nid[0] = 0x0a;
 	send_dht_request(t.dht_node, "find_node", t.source, &response
-		, msg_args().target("0101010101010101010101010101010101010101").nid(nid));
+		, msg_args()
+			.target(sha1_hash("0101010101010101010101010101010101010101"))
+			.nid(nid));
 
 	dht::key_desc_t const nodes_desc[] = {
 		{"y", bdecode_node::string_t, 1, 0},
@@ -981,7 +995,7 @@ namespace {
 		return nodes;
 	}
 
-	std::pair<char const*, int> const empty_salt(nullptr, 0);
+	span<char const> const empty_salt;
 }
 
 // TODO: 3 split this up into smaller tests
@@ -1018,41 +1032,42 @@ void test_put(address(&rand_addr)())
 
 	// ==== get / put mutable items ===
 
-	std::pair<char const*, int> itemv;
+	span<char const> itemv;
 
-	char signature[item_sig_len];
+	signature sig;
 	char buffer[1200];
-	int seq = 4;
+	sequence_number seq(4);
-	char public_key[item_pk_len];
+	public_key pk;
-	char private_key[item_sk_len];
+	secret_key sk;
-	get_test_keypair(public_key, private_key);
+	get_test_keypair(pk, sk);
 
+	// TODO: 4 pass in the actual salt as a parameter
 	for (int with_salt = 0; with_salt < 2; ++with_salt)
 	{
-		seq = 4;
+		seq = sequence_number(4);
 		std::fprintf(stderr, "\nTEST GET/PUT%s \ngenerating ed25519 keys\n\n"
 			, with_salt ? " with-salt" : " no-salt");
 		unsigned char seed[32];
 		ed25519_create_seed(seed);
 
-		ed25519_create_keypair((unsigned char*)public_key, (unsigned char*)private_key, seed);
+		ed25519_create_keypair((unsigned char*)pk.bytes.data()
+			, (unsigned char*)sk.bytes.data(), seed);
 		std::fprintf(stderr, "pub: %s priv: %s\n"
-			, aux::to_hex(std::string(public_key, item_pk_len)).c_str()
+			, aux::to_hex(std::string(pk.bytes.data(), public_key::len)).c_str()
-			, aux::to_hex(std::string(private_key, item_sk_len)).c_str());
+			, aux::to_hex(std::string(sk.bytes.data(), secret_key::len)).c_str());
 
-		std::pair<const char*, int> salt(nullptr, 0);
+		std::string salt;
-		if (with_salt)
+		if (with_salt) salt = "foobar";
-			salt = std::pair<char const*, int>("foobar", 6);
 
-		hasher h(public_key, 32);
+		hasher h(pk.bytes);
-		if (with_salt) h.update(salt.first, salt.second);
+		if (with_salt) h.update(salt);
 		sha1_hash target_id = h.final();
 
 		std::fprintf(stderr, "target_id: %s\n"
 			, aux::to_hex(target_id.to_string()).c_str());
 
 		send_dht_request(t.dht_node, "get", t.source, &response
-			, msg_args().target((char*)&target_id[0]));
+			, msg_args().target(target_id));
 
 		key_desc_t const desc[] =
 		{
@@ -1084,18 +1099,18 @@ void test_put(address(&rand_addr)())
 			TEST_ERROR(t.error_string);
 		}
 
-		itemv = std::pair<char const*, int>(buffer, bencode(buffer, items[0].ent));
+		itemv = span<char const>(buffer, bencode(buffer, items[0].ent));
-		sign_mutable_item(itemv, salt, seq, public_key, private_key, signature);
+		sign_mutable_item(itemv, salt, seq, pk, sk, sig);
-		TEST_EQUAL(verify_mutable_item(itemv, salt, seq, public_key, signature), true);
+		TEST_EQUAL(verify_mutable_item(itemv, salt, seq, pk, sig), true);
 
 		send_dht_request(t.dht_node, "put", t.source, &response
 			, msg_args()
 				.token(token)
 				.value(items[0].ent)
-				.key(std::string(public_key, item_pk_len))
+				.key(pk)
-				.sig(std::string(signature, item_sig_len))
+				.sig(sig)
 				.seq(seq)
-				.salt(salt.first));
+				.salt(salt));
 
 		ret = verify_message(response, desc2, desc2_keys, t.error_string
 			, sizeof(t.error_string));
@@ -1113,7 +1128,7 @@ void test_put(address(&rand_addr)())
 		}
 
 		send_dht_request(t.dht_node, "get", t.source, &response
-			, msg_args().target((char*)&target_id[0]));
+			, msg_args().target(target_id));
 
 		std::fprintf(stderr, "target_id: %s\n"
 			, aux::to_hex(target_id.to_string()).c_str());
@@ -1146,33 +1161,33 @@ void test_put(address(&rand_addr)())
 				, print_entry(response).c_str());
 			char value[1020];
 			char* ptr = value;
-			int value_len = bencode(ptr, items[0].ent);
+			int const value_len = bencode(ptr, items[0].ent);
-			TEST_EQUAL(value_len, desc3_keys[2].data_section().second);
+			TEST_EQUAL(value_len, int(desc3_keys[2].data_section().size()));
-			TEST_CHECK(memcmp(desc3_keys[2].data_section().first, value, value_len) == 0);
+			TEST_CHECK(memcmp(desc3_keys[2].data_section().data(), value, value_len) == 0);
 
-			TEST_EQUAL(seq, desc3_keys[3].int_value());
+			TEST_EQUAL(int(seq.value), desc3_keys[3].int_value());
 		}
 
 		// also test that invalid signatures fail!
 
-		itemv = std::pair<char const*, int>(buffer, bencode(buffer, items[0].ent));
+		itemv = span<char const>(buffer, bencode(buffer, items[0].ent));
-		sign_mutable_item(itemv, salt, seq, public_key, private_key, signature);
+		sign_mutable_item(itemv, salt, seq, pk, sk, sig);
-		TEST_EQUAL(verify_mutable_item(itemv, salt, seq, public_key, signature), 1);
+		TEST_EQUAL(verify_mutable_item(itemv, salt, seq, pk, sig), 1);
 		// break the signature
-		signature[2] ^= 0xaa;
+		sig.bytes[2] ^= 0xaa;
 
 		std::fprintf(stderr, "PUT broken signature\n");
 
-		TEST_CHECK(verify_mutable_item(itemv, salt, seq, public_key, signature) != 1);
+		TEST_CHECK(verify_mutable_item(itemv, salt, seq, pk, sig) != 1);
 
 		send_dht_request(t.dht_node, "put", t.source, &response
 			, msg_args()
 				.token(token)
 				.value(items[0].ent)
-				.key(std::string(public_key, item_pk_len))
+				.key(pk)
-				.sig(std::string(signature, item_sig_len))
+				.sig(sig)
 				.seq(seq)
-				.salt(salt.first));
+				.salt(salt));
 
 		ret = verify_message(response, desc_error, desc_error_keys, t.error_string
 			, sizeof(t.error_string));
@@ -1193,7 +1208,7 @@ void test_put(address(&rand_addr)())
 		// === test conditional get ===
 
 		send_dht_request(t.dht_node, "get", t.source, &response
-			, msg_args().target((char*)&target_id[0]).seq(seq - 1));
+			, msg_args().target(target_id).seq(prev_seq(seq)));
 
 		{
 			bdecode_node const r = response.dict_find_dict("r");
@@ -1203,7 +1218,7 @@ void test_put(address(&rand_addr)())
 		}
 
 		send_dht_request(t.dht_node, "get", t.source, &response
-			, msg_args().target((char*)&target_id[0]).seq(seq));
+			, msg_args().target(target_id).seq(seq));
 
 		{
 			bdecode_node r = response.dict_find_dict("r");
@@ -1215,16 +1230,16 @@ void test_put(address(&rand_addr)())
 		// === test CAS put ===
 
 		// this is the sequence number we expect to be there
-		std::uint64_t cas = seq;
+		sequence_number cas = seq;
 
 		// increment sequence number
-		++seq;
+		seq = next_seq(seq);
 		// put item 1
-		itemv = std::pair<char const*, int>(buffer, bencode(buffer, items[1].ent));
+		itemv = span<char const>(buffer, bencode(buffer, items[1].ent));
-		sign_mutable_item(itemv, salt, seq, public_key, private_key, signature);
+		sign_mutable_item(itemv, salt, seq, pk, sk, sig);
-		TEST_EQUAL(verify_mutable_item(itemv, salt, seq, public_key, signature), 1);
+		TEST_EQUAL(verify_mutable_item(itemv, salt, seq, pk, sig), 1);
 
-		TEST_CHECK(item_target_id(salt, public_key) == target_id);
+		TEST_CHECK(item_target_id(salt, pk) == target_id);
 
 		std::fprintf(stderr, "PUT CAS 1\n");
 
@@ -1232,11 +1247,11 @@ void test_put(address(&rand_addr)())
 			, msg_args()
 				.token(token)
 				.value(items[1].ent)
-				.key(std::string(public_key, item_pk_len))
+				.key(pk)
-				.sig(std::string(signature, item_sig_len))
+				.sig(sig)
 				.seq(seq)
 				.cas(cas)
-				.salt(salt.first));
+				.salt(salt));
 
 		ret = verify_message(response, desc2, desc2_keys, t.error_string
 			, sizeof(t.error_string));
@@ -1262,11 +1277,11 @@ void test_put(address(&rand_addr)())
 			, msg_args()
 				.token(token)
 				.value(items[1].ent)
-				.key(std::string(public_key, item_pk_len))
+				.key(pk)
-				.sig(std::string(signature, item_sig_len))
+				.sig(sig)
 				.seq(seq)
 				.cas(cas)
-				.salt(salt.first));
+				.salt(salt));
 
 		ret = verify_message(response, desc_error, desc_error_keys, t.error_string
 			, sizeof(t.error_string));
@@ -1767,23 +1782,22 @@ TORRENT_TEST(get_peers_v6)
 }
 #endif
 
+// TODO: 4 pass in th actual salt as the argument
 void test_mutable_get(address(&rand_addr)(), bool const with_salt)
 {
 	dht_test_setup t(udp::endpoint(rand_addr(), 20));
 
-	char public_key[item_pk_len];
+	public_key pk;
-	char private_key[item_sk_len];
+	secret_key sk;
-	get_test_keypair(public_key, private_key);
+	get_test_keypair(pk, sk);
 
-	char signature[item_sig_len];
 	char buffer[1200];
-	int seq = 4;
+	sequence_number seq(4);
-	std::pair<char const*, int> itemv;
+	span<char const> itemv;
 	bdecode_node response;
 
-	std::pair<const char*, int> salt(nullptr, 0);
+	std::string salt;
-	if (with_salt)
+	if (with_salt) salt = "foobar";
-		salt = std::pair<char const*, int>("foobar", 6);
 
 	// mutable get
 
@@ -1792,9 +1806,8 @@ void test_mutable_get(address(&rand_addr)(), bool const with_salt)
 	udp::endpoint const initial_node(rand_addr(), 1234);
 	t.dht_node.m_table.add_node(initial_node);
 
-	g_put_item.assign(items[0].ent, salt, seq, public_key, private_key);
+	g_put_item.assign(items[0].ent, salt, seq, pk, sk);
-	std::string sig(g_put_item.sig().data(), item_sig_len);
+	t.dht_node.put_item(pk, std::string()
-	t.dht_node.put_item(public_key, std::string()
 		, std::bind(&put_mutable_item_cb, _1, _2, 0)
 		, put_mutable_item_data_cb);
 
@@ -1804,7 +1817,7 @@ void test_mutable_get(address(&rand_addr)(), bool const with_salt)
 
 	g_sent_packets.clear();
 
-	t.dht_node.get_item(public_key, std::string(salt.first, salt.second), get_mutable_item_cb);
+	t.dht_node.get_item(pk, salt, get_mutable_item_cb);
 
 	TEST_EQUAL(g_sent_packets.size(), 1);
 	if (g_sent_packets.empty()) return;
@@ -1831,16 +1844,17 @@ void test_mutable_get(address(&rand_addr)(), bool const with_salt)
 
 	g_sent_packets.clear();
 
-	itemv = std::pair<char const*, int>(buffer, bencode(buffer, items[0].ent));
+	signature sig;
-	sign_mutable_item(itemv, salt, seq, public_key, private_key, signature);
+	itemv = span<char const>(buffer, bencode(buffer, items[0].ent));
+	sign_mutable_item(itemv, salt, seq, pk, sk, sig);
 	send_dht_response(t.dht_node, response, initial_node
 		, msg_args()
 			.token("10")
 			.port(1234)
 			.value(items[0].ent)
-			.key(std::string(public_key, item_pk_len))
+			.key(pk)
-			.sig(std::string(signature, item_sig_len))
+			.sig(sig)
-			.salt(salt.first)
+			.salt(salt)
 			.seq(seq));
 
 	TEST_CHECK(g_sent_packets.empty());
@@ -1848,9 +1862,9 @@ void test_mutable_get(address(&rand_addr)(), bool const with_salt)
 	if (g_got_items.empty()) return;
 
 	TEST_EQUAL(g_got_items.front().value(), items[0].ent);
-	TEST_CHECK(memcmp(g_got_items.front().pk().data(), public_key, item_pk_len) == 0);
+	TEST_CHECK(g_got_items.front().pk() == pk);
-	TEST_CHECK(memcmp(g_got_items.front().sig().data(), signature, item_sig_len) == 0);
+	TEST_CHECK(g_got_items.front().sig() == sig);
-	TEST_EQUAL(int(g_got_items.front().seq()), seq);
+	TEST_CHECK(g_got_items.front().seq() == seq);
 	g_got_items.clear();
 }
 
@@ -1929,7 +1943,7 @@ TORRENT_TEST(immutable_get)
 TORRENT_TEST(immutable_put)
 {
 	bdecode_node response;
-	std::pair<char const*, int> itemv;
+	span<char const> itemv;
 	char buffer[1200];
 
 	dht::key_desc_t const put_immutable_item_desc[] = {
@@ -1963,7 +1977,7 @@ TORRENT_TEST(immutable_put)
 		std::string flat_data;
 		bencode(std::back_inserter(flat_data), put_data);
 		sha1_hash target = item_target_id(
-			std::pair<char const*, int>(flat_data.c_str(), int(flat_data.size())));
+			span<char const>(flat_data.c_str(), int(flat_data.size())));
 
 		t.dht_node.put_item(target, put_data, std::bind(&put_immutable_item_cb, _1, loop));
 
@@ -1998,7 +2012,7 @@ TORRENT_TEST(immutable_put)
 		TEST_EQUAL(g_sent_packets.size(), 8);
 		if (g_sent_packets.size() != 8) break;
 
-		itemv = std::pair<char const*, int>(buffer, bencode(buffer, put_data));
+		itemv = span<char const>(buffer, bencode(buffer, put_data));
 
 		for (int i = 0; i < 8; ++i)
 		{
@@ -2013,8 +2027,8 @@ TORRENT_TEST(immutable_put)
 			{
 				TEST_EQUAL(put_immutable_item_keys[0].string_value(), "q");
 				TEST_EQUAL(put_immutable_item_keys[2].string_value(), "put");
-				std::pair<const char*, int> v = put_immutable_item_keys[6].data_section();
+				span<const char> v = put_immutable_item_keys[6].data_section();
-				TEST_EQUAL(std::string(v.first, v.second), flat_data);
+				TEST_EQUAL(std::string(v.data(), v.size()), flat_data);
 				char tok[10];
 				std::snprintf(tok, sizeof(tok), "%02d", i);
 				TEST_EQUAL(put_immutable_item_keys[5].string_value(), tok);
@@ -2039,14 +2053,14 @@ TORRENT_TEST(immutable_put)
 TORRENT_TEST(mutable_put)
 {
 	bdecode_node response;
-	std::pair<char const*, int> itemv;
+	span<char const> itemv;
 	char buffer[1200];
 	bdecode_node put_mutable_item_keys[11];
-	char public_key[item_pk_len];
+	public_key pk;
-	char private_key[item_sk_len];
+	secret_key sk;
-	get_test_keypair(public_key, private_key);
+	get_test_keypair(pk, sk);
 
-	int seq = 4;
+	sequence_number seq(4);
 
 	// mutable put
 	g_sent_packets.clear();
@@ -2063,9 +2077,9 @@ TORRENT_TEST(mutable_put)
 		for (int i = 0; i < num_test_nodes; ++i)
 			t.dht_node.m_table.add_node(nodes[i]);
 
-		g_put_item.assign(items[0].ent, empty_salt, seq, public_key, private_key);
+		g_put_item.assign(items[0].ent, empty_salt, seq, pk, sk);
-		std::string sig(g_put_item.sig().data(), item_sig_len);
+		signature const sig = g_put_item.sig();
-		t.dht_node.put_item(public_key, std::string()
+		t.dht_node.put_item(pk, std::string()
 				, std::bind(&put_mutable_item_cb, _1, _2, loop)
 				, put_mutable_item_data_cb);
 
@@ -2100,7 +2114,7 @@ TORRENT_TEST(mutable_put)
 		TEST_EQUAL(g_sent_packets.size(), 8);
 		if (g_sent_packets.size() != 8) break;
 
-		itemv = std::pair<char const*, int>(buffer, bencode(buffer, items[0].ent));
+		itemv = span<char const>(buffer, bencode(buffer, items[0].ent));
 
 		for (int i = 0; i < 8; ++i)
 		{
@@ -2115,12 +2129,12 @@ TORRENT_TEST(mutable_put)
 			{
 				TEST_EQUAL(put_mutable_item_keys[0].string_value(), "q");
 				TEST_EQUAL(put_mutable_item_keys[2].string_value(), "put");
-				TEST_EQUAL(put_mutable_item_keys[6].string_value(), std::string(public_key, item_pk_len));
+				TEST_EQUAL(put_mutable_item_keys[6].string_value(), std::string(pk.bytes.data(), public_key::len));
-				TEST_EQUAL(put_mutable_item_keys[7].int_value(), seq);
+				TEST_EQUAL(put_mutable_item_keys[7].int_value(), int(seq.value));
-				TEST_EQUAL(put_mutable_item_keys[8].string_value(), sig);
+				TEST_EQUAL(put_mutable_item_keys[8].string_value(), std::string(sig.bytes.data(), signature::len));
-				std::pair<const char*, int> v = put_mutable_item_keys[10].data_section();
+				span<const char> v = put_mutable_item_keys[10].data_section();
-				TEST_EQUAL(v.second, itemv.second);
+				TEST_EQUAL(v.size(), itemv.size());
-				TEST_CHECK(memcmp(v.first, itemv.first, itemv.second) == 0);
+				TEST_CHECK(memcmp(v.data(), itemv.data(), itemv.size()) == 0);
 				char tok[10];
 				std::snprintf(tok, sizeof(tok), "%02d", i);
 				TEST_EQUAL(put_mutable_item_keys[9].string_value(), tok);
@@ -2149,18 +2163,18 @@ TORRENT_TEST(traversal_done)
 	// set the branching factor to k to make this a little easier
 	t.sett.search_branching = 8;
 
-	char public_key[item_pk_len];
+	public_key pk;
-	char private_key[item_sk_len];
+	secret_key sk;
-	get_test_keypair(public_key, private_key);
+	get_test_keypair(pk, sk);
 
-	int seq = 4;
+	sequence_number seq(4);
 	bdecode_node response;
 
 	// verify that done() is only invoked once
 	// See PR 252
 	g_sent_packets.clear();
 
-	sha1_hash target = hasher(public_key, item_pk_len).final();
+	sha1_hash const target = hasher(pk.bytes).final();
 	enum { num_test_nodes = 9 }; // we need K + 1 nodes to create the failing sequence
 
 	std::array<node_entry, 9> nodes = build_nodes(target);
@@ -2175,8 +2189,8 @@ TORRENT_TEST(traversal_done)
 		t.dht_node.m_table.add_node(nodes[i]);
 
 	// kick off a mutable put request
-	g_put_item.assign(items[0].ent, empty_salt, seq, public_key, private_key);
+	g_put_item.assign(items[0].ent, empty_salt, seq, pk, sk);
-	t.dht_node.put_item(public_key, std::string()
+	t.dht_node.put_item(pk, std::string()
 		, std::bind(&put_mutable_item_cb, _1, _2, 0)
 		, put_mutable_item_data_cb);
 	TEST_EQUAL(g_sent_packets.size(), 8);
@@ -2259,7 +2273,9 @@ TORRENT_TEST(dht_dual_stack)
 	udp::endpoint source(addr("10.0.0.1"), 20);
 
 	send_dht_request(node4, "find_node", source, &response
-		, msg_args().target("0101010101010101010101010101010101010101").want("n6"));
+		, msg_args()
+			.target(sha1_hash("0101010101010101010101010101010101010101"))
+			.want("n6"));
 
 	dht::key_desc_t const nodes6_desc[] = {
 		{ "y", bdecode_node::string_t, 1, 0 },
@@ -2366,50 +2382,47 @@ TORRENT_TEST(signing_test1)
 	// test vector 1
 
 	// test content
-	std::pair<char const*, int> test_content("12:Hello World!", 15);
+	span<char const> test_content("12:Hello World!", 15);
 	// test salt
-	std::pair<char const*, int> test_salt("foobar", 6);
+	span<char const> test_salt("foobar", 6);
 
-	char public_key[item_pk_len];
+	public_key pk;
-	char private_key[item_sk_len];
+	secret_key sk;
-	get_test_keypair(public_key, private_key);
+	get_test_keypair(pk, sk);
-	std::pair<char const*, int> empty_salt;
+	span<char const> empty_salt;
 
-	char signature[item_sig_len];
+	signature sig;
+	sign_mutable_item(test_content, empty_salt, sequence_number(1), pk, sk, sig);
 
-	sign_mutable_item(test_content, empty_salt, 1, public_key
+	TEST_EQUAL(aux::to_hex(std::string(sig.bytes.data(), signature::len))
-		, private_key, signature);
-
-	TEST_EQUAL(aux::to_hex(std::string(signature, 64))
 		, "305ac8aeb6c9c151fa120f120ea2cfb923564e11552d06a5d856091e5e853cff"
 		"1260d3f39e4999684aa92eb73ffd136e6f4f3ecbfda0ce53a1608ecd7ae21f01");
 
-	sha1_hash target_id = item_target_id(empty_salt, public_key);
+	sha1_hash target_id = item_target_id(empty_salt, pk);
 	TEST_EQUAL(aux::to_hex(target_id.to_string()), "4a533d47ec9c7d95b1ad75f576cffc641853b750");
 }
 
 TORRENT_TEST(signing_test2)
 {
-	char public_key[item_pk_len];
+	public_key pk;
-	char private_key[item_sk_len];
+	secret_key sk;
-	get_test_keypair(public_key, private_key);
+	get_test_keypair(pk, sk);
 
 	// test content
-	std::pair<char const*, int> test_content("12:Hello World!", 15);
+	span<char const> test_content("12:Hello World!", 15);
 
-	char signature[item_sig_len];
+	signature sig;
 	// test salt
-	std::pair<char const*, int> test_salt("foobar", 6);
+	span<char const> test_salt("foobar", 6);
 
 	// test vector 2 (the keypair is the same as test 1)
-	sign_mutable_item(test_content, test_salt, 1, public_key
+	sign_mutable_item(test_content, test_salt, sequence_number(1), pk, sk, sig);
-		, private_key, signature);
 
-	TEST_EQUAL(aux::to_hex(std::string(signature, 64))
+	TEST_EQUAL(aux::to_hex(std::string(sig.bytes.data(), signature::len))
 		, "6834284b6b24c3204eb2fea824d82f88883a3d95e8b4a21b8c0ded553d17d17d"
 		"df9a8a7104b1258f30bed3787e6cb896fca78c58f8e03b5f18f14951a87d9a08");
 
-	sha1_hash target_id = item_target_id(test_salt, public_key);
+	sha1_hash target_id = item_target_id(test_salt, pk);
 	TEST_EQUAL(aux::to_hex(target_id.to_string()), "411eba73b6f087ca51a3795d9c8c938d365e32c1");
 }
 
@@ -2418,7 +2431,7 @@ TORRENT_TEST(signing_test3)
 	// test vector 3
 
 	// test content
-	std::pair<char const*, int> test_content("12:Hello World!", 15);
+	span<char const> test_content("12:Hello World!", 15);
 
 	sha1_hash target_id = item_target_id(test_content);
 	TEST_EQUAL(aux::to_hex(target_id.to_string()), "e5f96f6f38320f0f33959cb4d3d656452117aadb");
@@ -2704,7 +2717,7 @@ TORRENT_TEST(read_only_node)
 	send_dht_request(node, "ping", source, &response, args, "10", false);
 	TEST_EQUAL(response.type(), bdecode_node::none_t);
 
-	args.target("01010101010101010101");
+	args.target(sha1_hash("01010101010101010101"));
 	send_dht_request(node, "get", source, &response, args, "10", false);
 	TEST_EQUAL(response.type(), bdecode_node::none_t);
 

test/test_dht_storage.cpp

@@ -34,7 +34,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "libtorrent/config.hpp"
 #include "libtorrent/session.hpp"
-#include "libtorrent/kademlia/node.hpp" // for verify_message
+#include "libtorrent/kademlia/msg.hpp" // for verify_message
 #include "libtorrent/bencode.hpp"
 #include "libtorrent/socket_io.hpp" // for hash_address
 #include "libtorrent/broadcast_socket.hpp" // for supports_ipv6
@@ -138,23 +138,24 @@ TORRENT_TEST(put_immutable_item)
 	bool r = s->get_immutable_item(n4, item);
 	TEST_CHECK(!r);
 
-	s->put_immutable_item(n4, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n4, {"123", 3}, addr("124.31.75.21"));
 	r = s->get_immutable_item(n4, item);
 	TEST_CHECK(r);
 
-	s->put_immutable_item(n1, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n1, {"123", 3}, addr("124.31.75.21"));
-	s->put_immutable_item(n2, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n2, {"123", 3}, addr("124.31.75.21"));
-	s->put_immutable_item(n3, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n3, {"123", 3}, addr("124.31.75.21"));
 	r = s->get_immutable_item(n1, item);
 	TEST_CHECK(!r);
 
-	r = s->get_mutable_item(n4, 0, false, item);
+	r = s->get_mutable_item(n4, sequence_number(0), false, item);
 	TEST_CHECK(!r);
 
-	char public_key[item_pk_len];
+	public_key pk;
-	char signature[item_sig_len];
+	signature sig;
-	s->put_mutable_item(n4, "123", 3, signature, 1, public_key, "salt", 4, address::from_string("124.31.75.21"));
+	s->put_mutable_item(n4, {"123", 3}, sig, sequence_number(1), pk
-	r = s->get_mutable_item(n4, 0, false, item);
+		, {"salt", 4}, addr("124.31.75.21"));
+	r = s->get_mutable_item(n4, sequence_number(0), false, item);
 	TEST_CHECK(r);
 }
 
@@ -188,17 +189,18 @@ TORRENT_TEST(counters)
 
 	entry item;
 
-	s->put_immutable_item(n4, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n4, {"123", 3}, addr("124.31.75.21"));
 	TEST_EQUAL(s->counters().immutable_data, 1);
 
-	s->put_immutable_item(n1, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n1, {"123", 3}, addr("124.31.75.21"));
-	s->put_immutable_item(n2, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n2, {"123", 3}, addr("124.31.75.21"));
-	s->put_immutable_item(n3, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(n3, {"123", 3}, addr("124.31.75.21"));
 	TEST_EQUAL(s->counters().immutable_data, 2);
 
-	char public_key[item_pk_len];
+	public_key pk;
-	char signature[item_sig_len];
+	signature sig;
-	s->put_mutable_item(n4, "123", 3, signature, 1, public_key, "salt", 4, address::from_string("124.31.75.21"));
+	s->put_mutable_item(n4, {"123", 3}, sig, sequence_number(1), pk
+		, {"salt", 4}, addr("124.31.75.21"));
 	TEST_EQUAL(s->counters().mutable_data, 1);
 }
 
@@ -286,7 +288,7 @@ TORRENT_TEST(immutable_item_limit)
 
 	for (int i = 0; i < 200; ++i)
 	{
-		s->put_immutable_item(rand_hash(), "123", 3, rand_v4());
+		s->put_immutable_item(rand_hash(), {"123", 3}, rand_v4());
 		dht_storage_counters cnt = s->counters();
 		TEST_CHECK(cnt.immutable_data <= 42);
 	}
@@ -300,11 +302,12 @@ TORRENT_TEST(mutable_item_limit)
 	sett.max_dht_items = 42;
 	std::unique_ptr<dht_storage_interface> s(create_default_dht_storage(sett));
 
-	char public_key[item_pk_len];
+	public_key pk;
-	char signature[item_sig_len];
+	signature sig;
 	for (int i = 0; i < 200; ++i)
 	{
-		s->put_mutable_item(rand_hash(), "123", 3, signature, 1, public_key, "salt", 4, rand_v4());
+		s->put_mutable_item(rand_hash(), {"123", 3}, sig, sequence_number(1)
+			, pk, {"salt", 4}, rand_v4());
 		dht_storage_counters cnt = s->counters();
 		TEST_CHECK(cnt.mutable_data <= 42);
 	}
@@ -342,15 +345,15 @@ TORRENT_TEST(update_node_ids)
 
 	// all items will have one announcer, all calculations
 	// for item erase will be reduced to the distance
-	s->put_immutable_item(h1, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(h1, {"123", 3}, addr("124.31.75.21"));
 	cnt = s->counters();
 	TEST_EQUAL(cnt.immutable_data, 1);
-	s->put_immutable_item(h2, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(h2, {"123", 3}, addr("124.31.75.21"));
 	cnt = s->counters();
 	TEST_EQUAL(cnt.immutable_data, 2);
 	// at this point, the least important (h2) will removed
 	// to make room for h3
-	s->put_immutable_item(h3, "123", 3, address::from_string("124.31.75.21"));
+	s->put_immutable_item(h3, {"123", 3}, addr("124.31.75.21"));
 	cnt = s->counters();
 	TEST_EQUAL(cnt.immutable_data, 2);
 

test/test_direct_dht.cpp

@@ -69,8 +69,8 @@ dht_direct_response_alert* get_direct_response(lt::session& ses)
 {
 	for (;;)
 	{
-		alert* a = ses.wait_for_alert(seconds(20));
+		alert* a = ses.wait_for_alert(seconds(30));
-		// it shouldn't take more than 20 seconds to get a response
+		// it shouldn't take more than 30 seconds to get a response
 		// so fail the test and bail out if we don't get an alert in that time
 		TEST_CHECK(a);
 		if (!a) return nullptr;

tools/dht_put.cpp

@@ -37,6 +37,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/bencode.hpp" // for bencode()
 #include "libtorrent/kademlia/item.hpp" // for sign_mutable_item
 #include "libtorrent/ed25519.hpp"
+#include "libtorrent/span.hpp"
 
 #include <functional>
 #include <cstdio> // for snprintf
@@ -112,8 +113,11 @@ alert* wait_for_alert(lt::session& s, int alert_type)
 	return ret;
 }
 
-void put_string(entry& e, std::array<char, 64>& sig, std::uint64_t& seq
+void put_string(entry& e, std::array<char, 64>& sig
-	, std::string const& salt, char const* public_key, char const* private_key
+	, std::uint64_t& seq
+	, std::string const& salt
+	, std::array<char, 32> const& pk
+	, std::array<char, 64> const& sk
 	, char const* str)
 {
 	using libtorrent::dht::sign_mutable_item;
@@ -121,13 +125,12 @@ void put_string(entry& e, std::array<char, 64>& sig, std::uint64_t& seq
 	e = std::string(str);
 	std::vector<char> buf;
 	bencode(std::back_inserter(buf), e);
+	dht::signature sign;
 	++seq;
-	sign_mutable_item(std::pair<char const*, int>(&buf[0], int(buf.size()))
+	sign_mutable_item(buf, salt, dht::sequence_number(seq)
-		, std::pair<char const*, int>(&salt[0], int(salt.size()))
+		, dht::public_key(pk.data())
-		, seq
+		, dht::secret_key(sk.data()), sign);
-		, public_key
+	sig = sign.bytes;
-		, private_key
-		, sig.data());
 }
 
 void bootstrap(lt::session& s)
@@ -156,14 +159,14 @@ int dump_key(char *filename)
 	}
 	std::fclose(f);
 
-	std::array<char, 32> public_key;
+	std::array<char, 32> pk;
-	std::array<char, 64> private_key;
+	std::array<char, 64> sk;
-	ed25519_create_keypair((unsigned char*)public_key.data()
+	ed25519_create_keypair((unsigned char*)pk.data()
-		, (unsigned char*)private_key.data(), seed);
+		, (unsigned char*)sk.data(), seed);
 
-	std::printf("public key: %s\nprivate key: %s\n",
+	std::printf("public key: %s\nprivate key: %s\n"
-		to_hex(std::string(public_key.data(), public_key.size())).c_str(),
+		, to_hex(std::string(pk.data(), pk.size())).c_str()
-		to_hex(std::string(private_key.data(), private_key.size())).c_str());
+		, to_hex(std::string(sk.data(), sk.size())).c_str());
 
 	return 0;
 }
@@ -359,7 +362,7 @@ int main(int argc, char* argv[])
 
 		bootstrap(s);
 		s.dht_put_item(public_key, std::bind(&put_string, _1, _2, _3, _4
-			, public_key.data(), private_key.data(), argv[0]));
+			, public_key, private_key, argv[0]));
 
 		std::printf("MPUT publick key: %s\n", to_hex(std::string(public_key.data()
 			, public_key.size())).c_str());