Merge pull request #21333 from Chocobo1/random

Improve PRNG functions

src/base/utils/random.cpp

@@ -30,39 +30,37 @@
 
 #include <random>
 
+#include <QtLogging>
 #include <QtSystemDetection>
 
-#ifdef Q_OS_WIN
+#if defined(Q_OS_WIN)
 #include <windows.h>
-#include <ntsecapi.h>
-#else  // Q_OS_WIN
+#include "base/global.h"
+#include "base/utils/os.h"
+#elif defined(Q_OS_LINUX)
+#include <cerrno>
+#include <cstring>
+#include <sys/random.h>
+#else
 #include <cerrno>
 #include <cstdio>
 #include <cstring>
 #endif
 
-#include <QString>
-
-#include "base/global.h"
-
-#ifdef Q_OS_WIN
-#include "base/utils/os.h"
-#endif
-
 namespace
 {
-#ifdef Q_OS_WIN
+#if defined(Q_OS_WIN)
     class RandomLayer
     {
     // need to satisfy UniformRandomBitGenerator requirements
     public:
         using result_type = uint32_t;
 
         RandomLayer()
-            : m_rtlGenRandom {Utils::OS::loadWinAPI<PRTLGENRANDOM>(u"Advapi32.dll"_s, "SystemFunction036")}
+            : m_processPrng {Utils::OS::loadWinAPI<PPROCESSPRNG>(u"BCryptPrimitives.dll"_s, "ProcessPrng")}
         {
-            if (!m_rtlGenRandom)
-                qFatal("Failed to load RtlGenRandom()");
+            if (!m_processPrng)
+                qFatal("Failed to load ProcessPrng().");
         }
 
         static constexpr result_type min()
@@ -78,18 +76,57 @@ namespace
         result_type operator()()
         {
             result_type buf = 0;
-            const bool result = m_rtlGenRandom(&buf, sizeof(buf));
+            const bool result = m_processPrng(reinterpret_cast<PBYTE>(&buf), sizeof(buf));
             if (!result)
-                qFatal("RtlGenRandom() failed");
+                qFatal("ProcessPrng() failed.");
 
             return buf;
         }
 
     private:
-        using PRTLGENRANDOM = BOOLEAN (WINAPI *)(PVOID, ULONG);
-        const PRTLGENRANDOM m_rtlGenRandom;
+        using PPROCESSPRNG = BOOL (WINAPI *)(PBYTE, SIZE_T);
+        const PPROCESSPRNG m_processPrng;
+    };
+#elif defined(Q_OS_LINUX)
+    class RandomLayer
+    {
+    // need to satisfy UniformRandomBitGenerator requirements
+    public:
+        using result_type = uint32_t;
+
+        RandomLayer()
+        {
+        }
+
+        static constexpr result_type min()
+        {
+            return std::numeric_limits<result_type>::min();
+        }
+
+        static constexpr result_type max()
+        {
+            return std::numeric_limits<result_type>::max();
+        }
+
+        result_type operator()()
+        {
+            const int RETRY_MAX = 3;
+
+            for (int i = 0; i < RETRY_MAX; ++i)
+            {
+                result_type buf = 0;
+                const ssize_t result = ::getrandom(&buf, sizeof(buf), 0);
+                if (result == sizeof(buf))  // success
+                    return buf;
+
+                if (result < 0)
+                    qFatal("getrandom() error. Reason: %s. Error code: %d.", std::strerror(errno), errno);
+            }
+
+            qFatal("getrandom() failed. Reason: too many retries.");
+        }
     };
-#else  // Q_OS_WIN
+#else
     class RandomLayer
     {
     // need to satisfy UniformRandomBitGenerator requirements
@@ -100,7 +137,7 @@ namespace
             : m_randDev {fopen("/dev/urandom", "rb")}
         {
             if (!m_randDev)
-                qFatal("Failed to open /dev/urandom. Reason: %s. Error code: %d.\n", std::strerror(errno), errno);
+                qFatal("Failed to open /dev/urandom. Reason: %s. Error code: %d.", std::strerror(errno), errno);
         }
 
         ~RandomLayer()
@@ -122,7 +159,7 @@ namespace
         {
             result_type buf = 0;
             if (fread(&buf, sizeof(buf), 1, m_randDev) != 1)
-                qFatal("Read /dev/urandom error. Reason: %s. Error code: %d.\n", std::strerror(errno), errno);
+                qFatal("Read /dev/urandom error. Reason: %s. Error code: %d.", std::strerror(errno), errno);
 
             return buf;
         }