build: update version to 3.1.6

MinGW now has std::random_device support on Windows:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85494

CMakeLists.txt

@@ -15,7 +15,7 @@ include(cmake/CheckAtomic.cmake)
 include(CTest)
 
 set (opendht_VERSION_MAJOR 3)
-set (opendht_VERSION_MINOR 1.4)
+set (opendht_VERSION_MINOR 1.6)
 set (opendht_VERSION ${opendht_VERSION_MAJOR}.${opendht_VERSION_MINOR})
 set (PACKAGE_VERSION ${opendht_VERSION})
 set (VERSION "${opendht_VERSION}")

configure.ac

@@ -1,7 +1,7 @@
 dnl define macros
 m4_define([opendht_major_version], 3)
 m4_define([opendht_minor_version], 1)
-m4_define([opendht_patch_version], 4)
+m4_define([opendht_patch_version], 6)
 m4_define([opendht_version],
 		  [opendht_major_version.opendht_minor_version.opendht_patch_version])
 

include/opendht/crypto.h

@@ -685,7 +685,7 @@ public:
 
     static secure_vector<T> getRandom(size_t size) {
         secure_vector<T> ret(size);
-        crypto::random_device rdev;
+        std::random_device rdev;
 #ifdef _WIN32
         std::uniform_int_distribution<int> rand_byte{ 0, std::numeric_limits<uint8_t>::max() };
 #else

include/opendht/dht.h

@@ -65,7 +65,7 @@ public:
      * Initialise the Dht with two open sockets (for IPv4 and IP6)
      * and an ID for the node.
      */
-    Dht(std::unique_ptr<net::DatagramSocket>&& sock, const Config& config, const Sp<Logger>& l = {});
+    Dht(std::unique_ptr<net::DatagramSocket>&& sock, const Config& config, const Sp<Logger>& l = {}, std::unique_ptr<std::mt19937_64>&& rd = {});
 
     virtual ~Dht();
 
@@ -372,7 +372,7 @@ private:
     Dht(const Dht&) = delete;
     Dht& operator=(const Dht&) = delete;
 
-    std::mt19937_64 rd {crypto::getSeededRandomEngine<std::mt19937_64>()};
+    std::mt19937_64 rd;
 
     InfoHash myid {};
 

include/opendht/dhtrunner.h

@@ -79,6 +79,7 @@ public:
         CertificateStoreQuery certificateStore {};
         IdentityAnnouncedCb identityAnnouncedCb {};
         PublicAddressChangedCb publicAddressChangedCb {};
+        std::unique_ptr<std::mt19937_64> rng {};
         Context() {}
     };
 

include/opendht/infohash.h

@@ -323,7 +323,7 @@ Hash<N>
 Hash<N>::getRandom()
 {
     Hash h;
-    crypto::random_device rdev;
+    std::random_device rdev;
     std::uniform_int_distribution<uint32_t> rand_int;
     auto a = reinterpret_cast<uint32_t*>(h.data());
     auto b = reinterpret_cast<uint32_t*>(h.data() + h.size());

include/opendht/rng.h

@@ -27,104 +27,47 @@
 namespace dht {
 namespace crypto {
 
-#ifndef _MSC_VER
-#ifdef _WIN32
-
-/**
- * Hardware random number generator using Intel RDRAND/RDSEED,
- * API-compatible with std::random_device.
+/** 
+ * Generate a seeded random engine.
  */
-class random_device {
-public:
-    using result_type = std::random_device::result_type;
-    using pseudo_engine = std::mt19937_64;
-
-    /**
-     * Current implementation assumption : result_type must be of a size
-     * supported by Intel RDRAND/RDSEED.
-     * result_type is unsigned int so this is currently safe.
-     */
-    static_assert(
-        sizeof(result_type) == 2 ||
-        sizeof(result_type) == 4 ||
-        sizeof(result_type) == 8,
-        "result_type must be 16, 32 or 64 bits");
-
-    random_device();
-
-    result_type operator()();
-
-    static constexpr result_type min() {
-        return std::numeric_limits<result_type>::lowest();
-    }
-
-    static constexpr result_type max() {
-        return std::numeric_limits<result_type>::max();
-    }
-
-    double entropy() const {
-        if (hasRdrand() or hasRdseed())
-            return 1.;
-        return 0.;
-    }
-
-    static bool hasRdrand() {
-        static const bool hasrdrand = _hasRdrand();
-        return hasrdrand;
-    }
-
-    static bool hasRdseed() {
-        static const bool hasrdseed = _hasRdseed();
-        return hasrdseed;
-    }
-
-private:
-    random_device& operator=(random_device&) = delete;
-
-    pseudo_engine gen;
-    std::uniform_int_distribution<result_type> dis {};
-
-    static bool hasIntelCpu();
-    static bool _hasRdrand();
-    static bool _hasRdseed();
-
-    struct CPUIDinfo {
-        unsigned int EAX;
-        unsigned int EBX;
-        unsigned int ECX;
-        unsigned int EDX;
-        CPUIDinfo(const unsigned int func, const unsigned int subfunc);
+template<class T = std::mt19937, std::size_t N = T::state_size+1>
+auto getSeededRandomEngine() -> typename std::enable_if<!!N, T>::type {
+    std::array<typename T::result_type, N> random_data;
+    constexpr auto gen = [](std::random_device& source) -> typename T::result_type {
+        for (unsigned j=0; j<64; j++) {
+            try {
+                return source();
+            } catch (...) {
+                std::this_thread::sleep_for(std::chrono::microseconds(500));
+            }
+        }
+        throw std::runtime_error("Can't generate random number");
     };
-    bool rdrandStep(result_type* r);
-    bool rdrand(result_type* r);
-    bool rdseedStep(result_type* r);
-    bool rdseed(result_type* r);
-};
-
-#else
-
-using random_device = std::random_device;
-
-#endif
-#else
-using random_device = std::random_device;
-#endif
-
-template<class T = std::mt19937, std::size_t N = T::state_size>
-auto getSeededRandomEngine () -> typename std::enable_if<!!N, T>::type {
-    typename T::result_type random_data[N];
-    for (unsigned i=0; i<256; i++) {
+    for (unsigned i=0; i<8; i++) {
         try {
-            random_device source;
-            std::generate(std::begin(random_data), std::end(random_data), std::ref(source));
-            std::seed_seq seeds(std::begin(random_data), std::end(random_data));
-            T seededEngine (seeds);
-            return seededEngine;
+            std::random_device source;
+            for (auto& r : random_data)
+                r = gen(source);
+            std::seed_seq seed(
+                (std::seed_seq::result_type*)random_data.data(),
+                (std::seed_seq::result_type*)(random_data.data() + random_data.size()));
+            return T(seed);
         } catch (...) {
-            std::this_thread::sleep_for(std::chrono::milliseconds(1));
+            std::this_thread::sleep_for(std::chrono::microseconds(500));
         }
     }
-    throw std::runtime_error("Can't seed random engine");
+    throw std::runtime_error("Can't seed random seed");
+}
+
+/**
+ * Generate a random engine from another source.
+ */
+template<class T = std::mt19937, std::size_t N = T::state_size+1>
+auto getDerivedRandomEngine(T& source) -> typename std::enable_if<!!N, T>::type {
+    std::array<typename T::result_type, N> random_data;
+    std::generate(random_data.begin(), random_data.end(), std::ref(source));
+    std::seed_seq seed(random_data.begin(), random_data.end());
+    return T(seed);
 }
 
 }} // dht::crypto

meson.build

@@ -1,5 +1,5 @@
 project('opendht', 'c', 'cpp',
-    version: '3.1.4',
+    version: '3.1.6',
     default_options: [
         'cpp_std=c++17',
         'warning_level=3'

src/crypto.cpp

@@ -92,7 +92,7 @@ Blob aesEncrypt(const uint8_t* data, size_t data_length, const Blob& key)
 
     Blob ret(data_length + GCM_IV_SIZE + GCM_DIGEST_SIZE);
     {
-        crypto::random_device rdev;
+        std::random_device rdev;
         std::generate_n(ret.begin(), GCM_IV_SIZE, std::bind(rand_byte, std::ref(rdev)));
     }
     struct gcm_aes_ctx aes;
@@ -191,7 +191,7 @@ Blob stretchKey(std::string_view password, Blob& salt, size_t key_length)
 {
     if (salt.empty()) {
         salt.resize(PASSWORD_SALT_LENGTH);
-        crypto::random_device rdev;
+        std::random_device rdev;
         std::generate_n(salt.begin(), salt.size(), std::bind(rand_byte, std::ref(rdev)));
     }
     Blob res;
@@ -539,7 +539,7 @@ PublicKey::encrypt(const uint8_t* data, size_t data_len) const
         throw CryptoException("Key is not long enough for AES128");
     Blob key(aes_key_sz);
     {
-        crypto::random_device rdev;
+        std::random_device rdev;
         std::generate_n(key.begin(), key.size(), std::bind(rand_byte, std::ref(rdev)));
     }
     auto data_encrypted = aesEncrypt(data, data_len, key);
@@ -1193,7 +1193,7 @@ setValidityPeriod(gnutls_x509_crt_t cert, int64_t validity)
 void
 setRandomSerial(gnutls_x509_crt_t cert)
 {
-    random_device rdev;
+    std::random_device rdev;
     std::uniform_int_distribution<int64_t> dist{1};
     int64_t cert_serial = dist(rdev);
     gnutls_x509_crt_set_serial(cert, &cert_serial, sizeof(cert_serial));
@@ -1666,7 +1666,7 @@ RevocationList::sign(const PrivateKey& key, const Certificate& ca, duration vali
     if (number == 0) {
         // initialize to a random number
         number_sz = sizeof(number);
-        random_device rdev;
+        std::random_device rdev;
         std::generate_n((uint8_t*)&number, sizeof(number), std::bind(rand_byte, std::ref(rdev)));
     } else
         number = endian(endian(number) + 1);

src/dht.cpp

@@ -1815,8 +1815,9 @@ fromDhtConfig(const Config& config)
     return netConf;
 }
 
-Dht::Dht(std::unique_ptr<net::DatagramSocket>&& sock, const Config& config, const Sp<Logger>& l)
+Dht::Dht(std::unique_ptr<net::DatagramSocket>&& sock, const Config& config, const Sp<Logger>& l, std::unique_ptr<std::mt19937_64>&& rda)
     : DhtInterface(l),
+    rd(rda ? std::move(*rda) : crypto::getSeededRandomEngine<std::mt19937_64>()),
     myid(config.node_id ? config.node_id : InfoHash::getRandom(rd)),
     store(),
     store_quota(),

src/dht_proxy_client.cpp

@@ -98,7 +98,7 @@ std::string
 getRandomSessionId(size_t length = 8) {
     static constexpr const char chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!#$%&()*+,./:;<=>?@[]^_`{|}~";
     std::string str(length, 0);
-    crypto::random_device rdev;
+    std::random_device rdev;
     std::uniform_int_distribution<> dist(0, (sizeof(chars)/sizeof(char)) - 2);
     std::generate_n( str.begin(), length, [&]{ return chars[dist(rdev)]; } );
     return str;

src/dhtrunner.cpp

@@ -167,7 +167,7 @@ DhtRunner::run(const Config& config, Context&& context)
                 outConfig << context.sock->getBoundRef(AF_INET).getPort() << std::endl;
                 outConfig << context.sock->getBoundRef(AF_INET6).getPort() << std::endl;
             }
-            auto dht = std::make_unique<Dht>(std::move(context.sock), SecureDht::getConfig(config.dht_config), context.logger);
+            auto dht = std::make_unique<Dht>(std::move(context.sock), SecureDht::getConfig(config.dht_config), context.logger, std::move(context.rng));
             dht_ = std::make_unique<SecureDht>(std::move(dht), config.dht_config, std::move(context.identityAnnouncedCb), context.logger);
         } else {
             enableProxy(true);

src/indexation/pht.cpp

@@ -316,7 +316,7 @@ void Pht::updateCanary(Prefix p) {
     dht_->put(p.hash(), std::move(canary_value),
         [=](bool){
             static std::bernoulli_distribution d(0.5);
-            crypto::random_device rd;
+            std::random_device rd;
             if (p.size_ and d(rd))
                 updateCanary(p.getPrefix(-1));
         }

src/search.h

@@ -854,12 +854,17 @@ Dht::Search::insertNode(const Sp<Node>& snode, time_point now, const Blob& token
             expired = false;
         }
 
-        while (nodes.size() - bad >  SEARCH_NODES) {
+        while (nodes.size() - bad > SEARCH_NODES) {
+            bool removingNode = nodes.back()->node == snode;
             if (not expired and nodes.back()->isBad())
                 bad--;
             nodes.pop_back();
+            if (removingNode)
+                return false;
         }
     }
+    if (n == nodes.end() or not *n)
+        return false;
     if (not token.empty()) {
         (*n)->candidate = false;
         (*n)->last_get_reply = now;

src/securedht.cpp

@@ -337,7 +337,7 @@ SecureDht::putSigned(const InfoHash& hash, Sp<Value> val, DoneCallback callback,
         return;
     }
     if (val->id == Value::INVALID_ID) {
-        crypto::random_device rdev;
+        std::random_device rdev;
         std::uniform_int_distribution<Value::Id> rand_id;
         val->id = rand_id(rdev);
     }

tools/dhtchat.cpp

@@ -30,7 +30,7 @@ extern "C" {
 
 using namespace dht;
 
-static std::mt19937_64 rd {dht::crypto::random_device{}()};
+static std::mt19937_64 rd {dht::crypto::getSeededRandomEngine<std::mt19937_64>()};
 static std::uniform_int_distribution<dht::Value::Id> rand_id;
 
 const std::string printTime(const std::time_t& now) {