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authorPhilip Kaufmann <phil.kaufmann@t-online.de>2014-06-26 14:41:53 +0200
committerPhilip Kaufmann <phil.kaufmann@t-online.de>2014-07-09 09:42:19 +0200
commit6354935c485d116e1965567561c197ab3fbc0e11 (patch)
tree9dc218c1ed2fad513df1cf309f5ecd271069067a /src/random.cpp
parent001a53d7427dcbcceef3c6754d9cca19df6dafa1 (diff)
move rand functions from util to new random.h/.cpp
Diffstat (limited to 'src/random.cpp')
-rw-r--r--src/random.cpp140
1 files changed, 140 insertions, 0 deletions
diff --git a/src/random.cpp b/src/random.cpp
new file mode 100644
index 0000000000..4c7f150f75
--- /dev/null
+++ b/src/random.cpp
@@ -0,0 +1,140 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2014 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "random.h"
+
+#ifdef WIN32
+#include "compat.h" // for Windows API
+#endif
+#include "util.h" // for LogPrint()
+
+#ifndef WIN32
+#include <sys/time.h>
+#endif
+#include <cstring> // for memset()
+
+#include <openssl/crypto.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+
+static inline int64_t GetPerformanceCounter()
+{
+ int64_t nCounter = 0;
+#ifdef WIN32
+ QueryPerformanceCounter((LARGE_INTEGER*)&nCounter);
+#else
+ timeval t;
+ gettimeofday(&t, NULL);
+ nCounter = (int64_t)(t.tv_sec * 1000000 + t.tv_usec);
+#endif
+ return nCounter;
+}
+
+void RandAddSeed()
+{
+ // Seed with CPU performance counter
+ int64_t nCounter = GetPerformanceCounter();
+ RAND_add(&nCounter, sizeof(nCounter), 1.5);
+ memset(&nCounter, 0, sizeof(nCounter));
+}
+
+void RandAddSeedPerfmon()
+{
+ RandAddSeed();
+
+ // This can take up to 2 seconds, so only do it every 10 minutes
+ static int64_t nLastPerfmon;
+ if (GetTime() < nLastPerfmon + 10 * 60)
+ return;
+ nLastPerfmon = GetTime();
+
+#ifdef WIN32
+ // Don't need this on Linux, OpenSSL automatically uses /dev/urandom
+ // Seed with the entire set of perfmon data
+ std::vector <unsigned char> vData(250000,0);
+ long ret = 0;
+ unsigned long nSize = 0;
+ const size_t nMaxSize = 10000000; // Bail out at more than 10MB of performance data
+ while (true)
+ {
+ nSize = vData.size();
+ ret = RegQueryValueExA(HKEY_PERFORMANCE_DATA, "Global", NULL, NULL, begin_ptr(vData), &nSize);
+ if (ret != ERROR_MORE_DATA || vData.size() >= nMaxSize)
+ break;
+ vData.resize(std::max((vData.size()*3)/2, nMaxSize)); // Grow size of buffer exponentially
+ }
+ RegCloseKey(HKEY_PERFORMANCE_DATA);
+ if (ret == ERROR_SUCCESS)
+ {
+ RAND_add(begin_ptr(vData), nSize, nSize/100.0);
+ OPENSSL_cleanse(begin_ptr(vData), nSize);
+ LogPrint("rand", "%s: %lu bytes\n", __func__, nSize);
+ } else {
+ static bool warned = false; // Warn only once
+ if (!warned)
+ {
+ LogPrintf("%s: Warning: RegQueryValueExA(HKEY_PERFORMANCE_DATA) failed with code %i\n", __func__, ret);
+ warned = true;
+ }
+ }
+#endif
+}
+
+bool GetRandBytes(unsigned char *buf, int num)
+{
+ if (RAND_bytes(buf, num) != 1) {
+ LogPrintf("%s: OpenSSL RAND_bytes() failed with error: %s\n", __func__, ERR_error_string(ERR_get_error(), NULL));
+ return false;
+ }
+ return true;
+}
+
+uint64_t GetRand(uint64_t nMax)
+{
+ if (nMax == 0)
+ return 0;
+
+ // The range of the random source must be a multiple of the modulus
+ // to give every possible output value an equal possibility
+ uint64_t nRange = (std::numeric_limits<uint64_t>::max() / nMax) * nMax;
+ uint64_t nRand = 0;
+ do {
+ GetRandBytes((unsigned char*)&nRand, sizeof(nRand));
+ } while (nRand >= nRange);
+ return (nRand % nMax);
+}
+
+int GetRandInt(int nMax)
+{
+ return GetRand(nMax);
+}
+
+uint256 GetRandHash()
+{
+ uint256 hash;
+ GetRandBytes((unsigned char*)&hash, sizeof(hash));
+ return hash;
+}
+
+uint32_t insecure_rand_Rz = 11;
+uint32_t insecure_rand_Rw = 11;
+void seed_insecure_rand(bool fDeterministic)
+{
+ // The seed values have some unlikely fixed points which we avoid.
+ if(fDeterministic)
+ {
+ insecure_rand_Rz = insecure_rand_Rw = 11;
+ } else {
+ uint32_t tmp;
+ do {
+ GetRandBytes((unsigned char*)&tmp, 4);
+ } while(tmp == 0 || tmp == 0x9068ffffU);
+ insecure_rand_Rz = tmp;
+ do {
+ GetRandBytes((unsigned char*)&tmp, 4);
+ } while(tmp == 0 || tmp == 0x464fffffU);
+ insecure_rand_Rw = tmp;
+ }
+}