1 /* 2 * libjingle 3 * Copyright 2004--2005, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "talk/base/helpers.h" 29 30 #ifdef WIN32 31 #define WIN32_LEAN_AND_MEAN 32 #include <windows.h> 33 #include <ntsecapi.h> 34 #else 35 #ifdef SSL_USE_OPENSSL 36 #include <openssl/rand.h> 37 #endif 38 #endif 39 40 #include "talk/base/base64.h" 41 #include "talk/base/logging.h" 42 #include "talk/base/scoped_ptr.h" 43 #include "talk/base/time.h" 44 45 namespace talk_base { 46 47 // Base class for RNG implementations. 48 class RandomGenerator { 49 public: 50 virtual ~RandomGenerator() {} 51 virtual bool Init(const void* seed, size_t len) = 0; 52 virtual bool Generate(void* buf, size_t len) = 0; 53 }; 54 55 // The real random generators, using either CryptoAPI or OpenSSL. 56 // We also support the 'old' generator on Mac/Linux until we have time to 57 // fully test the OpenSSL one. 58 #ifdef WIN32 59 class SecureRandomGenerator : public RandomGenerator { 60 public: 61 SecureRandomGenerator() : advapi32_(NULL), rtl_gen_random_(NULL) {} 62 ~SecureRandomGenerator() { 63 FreeLibrary(advapi32_); 64 } 65 66 virtual bool Init(const void* seed, size_t seed_len) { 67 // We don't do any additional seeding on Win32, we just use the CryptoAPI 68 // RNG (which is exposed as a hidden function off of ADVAPI32 so that we 69 // don't need to drag in all of CryptoAPI) 70 if (rtl_gen_random_) { 71 return true; 72 } 73 74 advapi32_ = LoadLibrary(L"advapi32.dll"); 75 if (!advapi32_) { 76 return false; 77 } 78 79 rtl_gen_random_ = reinterpret_cast<RtlGenRandomProc>( 80 GetProcAddress(advapi32_, "SystemFunction036")); 81 if (!rtl_gen_random_) { 82 FreeLibrary(advapi32_); 83 return false; 84 } 85 86 return true; 87 } 88 virtual bool Generate(void* buf, size_t len) { 89 if (!rtl_gen_random_ && !Init(NULL, 0)) { 90 return false; 91 } 92 return (rtl_gen_random_(buf, len) != FALSE); 93 } 94 95 private: 96 typedef BOOL (WINAPI *RtlGenRandomProc)(PVOID, ULONG); 97 HINSTANCE advapi32_; 98 RtlGenRandomProc rtl_gen_random_; 99 }; 100 #else 101 #ifndef SSL_USE_OPENSSL 102 // The old RNG. 103 class SecureRandomGenerator : public RandomGenerator { 104 public: 105 SecureRandomGenerator() : seed_(1) { 106 } 107 ~SecureRandomGenerator() { 108 } 109 virtual bool Init(const void* seed, size_t len) { 110 uint32 hash = 0; 111 for (size_t i = 0; i < len; ++i) { 112 hash = ((hash << 2) + hash) + static_cast<const char*>(seed)[i]; 113 } 114 115 seed_ = Time() ^ hash; 116 return true; 117 } 118 virtual bool Generate(void* buf, size_t len) { 119 for (size_t i = 0; i < len; ++i) { 120 static_cast<uint8*>(buf)[i] = static_cast<uint8>(GetRandom()); 121 } 122 return true; 123 } 124 125 private: 126 int GetRandom() { 127 return ((seed_ = seed_ * 214013L + 2531011L) >> 16) & 0x7fff; 128 } 129 int seed_; 130 }; 131 #else 132 // The OpenSSL RNG. Need to make sure it doesn't run out of entropy. 133 class SecureRandomGenerator : public RandomGenerator { 134 public: 135 SecureRandomGenerator() : inited_(false) { 136 } 137 ~SecureRandomGenerator() { 138 } 139 virtual bool Init(const void* seed, size_t len) { 140 // By default, seed from the system state. 141 if (!inited_) { 142 if (RAND_poll() <= 0) { 143 return false; 144 } 145 inited_ = true; 146 } 147 // Allow app data to be mixed in, if provided. 148 if (seed) { 149 RAND_seed(seed, len); 150 } 151 return true; 152 } 153 virtual bool Generate(void* buf, size_t len) { 154 if (!inited_ && !Init(NULL, 0)) { 155 return false; 156 } 157 return (RAND_bytes(reinterpret_cast<unsigned char*>(buf), len) > 0); 158 } 159 160 private: 161 bool inited_; 162 }; 163 #endif // SSL_USE_OPENSSL 164 #endif // WIN32 165 166 // A test random generator, for predictable output. 167 class TestRandomGenerator : public RandomGenerator { 168 public: 169 TestRandomGenerator() : seed_(7) { 170 } 171 ~TestRandomGenerator() { 172 } 173 virtual bool Init(const void* seed, size_t len) { 174 return true; 175 } 176 virtual bool Generate(void* buf, size_t len) { 177 for (size_t i = 0; i < len; ++i) { 178 static_cast<uint8*>(buf)[i] = static_cast<uint8>(GetRandom()); 179 } 180 return true; 181 } 182 183 private: 184 int GetRandom() { 185 return ((seed_ = seed_ * 214013L + 2531011L) >> 16) & 0x7fff; 186 } 187 int seed_; 188 }; 189 190 // TODO: Use Base64::Base64Table instead. 191 static const char BASE64[64] = { 192 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 193 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 194 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 195 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 196 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/' 197 }; 198 199 static scoped_ptr<RandomGenerator> g_rng(new SecureRandomGenerator()); 200 201 void SetRandomTestMode(bool test) { 202 if (!test) { 203 g_rng.reset(new SecureRandomGenerator()); 204 } else { 205 g_rng.reset(new TestRandomGenerator()); 206 } 207 } 208 209 bool InitRandom(int seed) { 210 return InitRandom(reinterpret_cast<const char*>(&seed), sizeof(seed)); 211 } 212 213 bool InitRandom(const char* seed, size_t len) { 214 if (!g_rng->Init(seed, len)) { 215 LOG(LS_ERROR) << "Failed to init random generator!"; 216 return false; 217 } 218 return true; 219 } 220 221 std::string CreateRandomString(size_t len) { 222 std::string str; 223 CreateRandomString(len, &str); 224 return str; 225 } 226 227 bool CreateRandomString(size_t len, std::string* str) { 228 str->clear(); 229 scoped_array<uint8> bytes(new uint8[len]); 230 if (!g_rng->Generate(bytes.get(), len)) { 231 LOG(LS_ERROR) << "Failed to generate random string!"; 232 return false; 233 } 234 str->reserve(len); 235 for (size_t i = 0; i < len; ++i) { 236 str->push_back(BASE64[bytes[i] & 63]); 237 } 238 return true; 239 } 240 241 uint32 CreateRandomId() { 242 uint32 id; 243 if (!g_rng->Generate(&id, sizeof(id))) { 244 LOG(LS_ERROR) << "Failed to generate random id!"; 245 } 246 return id; 247 } 248 249 uint32 CreateRandomNonZeroId() { 250 uint32 id; 251 do { 252 id = CreateRandomId(); 253 } while (id == 0); 254 return id; 255 } 256 257 } // namespace talk_base 258
