initial commit

crypto/openssl/rand.cpp

@@ -0,0 +1,122 @@
+/*
+    This file is part of TON Blockchain Library.
+
+    TON Blockchain Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 2 of the License, or
+    (at your option) any later version.
+
+    TON Blockchain Library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2017-2019 Telegram Systems LLP
+*/
+#include "openssl/rand.hpp"
+
+#include "td/utils/common.h"
+
+#include <openssl/rand.h>
+#include <openssl/opensslv.h>
+
+namespace prng {
+int os_get_random_bytes(void *buf, int n);
+
+bool RandomGen::ok() const {
+  return RAND_status();
+}
+
+void RandomGen::seed_add(const void *data, std::size_t size, double entropy) {
+  RAND_add(data, static_cast<int>(size), entropy > 0 ? entropy : static_cast<double>(size));
+}
+
+void RandomGen::randomize(bool force) {
+  if (!force && ok()) {
+    return;
+  }
+  unsigned char buffer[128];
+  int n = os_get_random_bytes(buffer, 128);
+  seed_add(buffer, n);
+  assert(ok());
+}
+
+bool RandomGen::rand_bytes(void *data, std::size_t size, bool strong) {
+#if OPENSSL_VERSION_NUMBER < 0x10101000L
+  int res = (strong ? RAND_bytes : RAND_pseudo_bytes)((unsigned char *)data, static_cast<int>(size));
+#else
+  int res = RAND_bytes((unsigned char *)data, static_cast<int>(size));
+#endif
+  if (res != 0 && res != 1) {
+    throw rand_error();
+  }
+  return res;
+}
+
+std::string RandomGen::rand_string(std::size_t size, bool strong) {
+  std::string result(size, '\0');
+  if (size > 0 && !rand_bytes(&result[0], size, strong)) {
+    throw rand_error();
+  }
+  return result;
+}
+
+RandomGen &rand_gen() {
+  // RandomGen is stateless, OpenSSL will handle concurrent access
+  static RandomGen MainPRNG;
+  return MainPRNG;
+}
+}  // namespace prng
+
+//------------------------- move to separate OS-dependent file?
+#if TD_WINDOWS
+namespace prng {
+int os_get_random_bytes(void *buf, int n) {
+  return 0;
+}
+}  // namespace prng
+#else
+#include <fcntl.h>
+#include <unistd.h>
+
+namespace prng {
+
+int os_get_random_bytes(void *buf, int n) {
+  using namespace std;
+  int r = 0;
+  int h = open("/dev/random", O_RDONLY | O_NONBLOCK);
+  if (h >= 0) {
+    r = static_cast<int>(read(h, buf, n));
+    if (r > 0) {
+      //std::cerr << "added " << r << " bytes of real entropy to secure random numbers seed" << std::endl;
+    } else {
+      r = 0;
+    }
+    close(h);
+  }
+
+  if (r < n) {
+    h = open("/dev/urandom", O_RDONLY);
+    if (h < 0) {
+      return r;
+    }
+    int s = static_cast<int>(read(h, (char *)buf + r, n - r));
+    close(h);
+    if (s < 0) {
+      return r;
+    }
+    r += s;
+  }
+
+  if (r >= 8) {
+    *(long *)buf ^= lrand48();
+    srand48(*(long *)buf);
+  }
+
+  return r;
+}
+}  // namespace prng
+#endif