The Tor Browser / file comparison
comparison: xpcom/base/nsUUIDGenerator.cpp
xpcom/base/nsUUIDGenerator.cpp
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:f4732633e1e5 |
|---|---|
| 1 /* -*- Mode: C++; tab-width: 50; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ | |
| 2 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 3 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 5 | |
| 6 #if defined(XP_WIN) | |
| 7 #include <windows.h> | |
| 8 #include <objbase.h> | |
| 9 #elif defined(XP_MACOSX) | |
| 10 #include <CoreFoundation/CoreFoundation.h> | |
| 11 #else | |
| 12 #include <stdlib.h> | |
| 13 #include "prrng.h" | |
| 14 #endif | |
| 15 | |
| 16 #include "nsUUIDGenerator.h" | |
| 17 | |
| 18 using namespace mozilla; | |
| 19 | |
| 20 NS_IMPL_ISUPPORTS(nsUUIDGenerator, nsIUUIDGenerator) | |
| 21 | |
| 22 nsUUIDGenerator::nsUUIDGenerator() | |
| 23 : mLock("nsUUIDGenerator.mLock") | |
| 24 { | |
| 25 } | |
| 26 | |
| 27 nsUUIDGenerator::~nsUUIDGenerator() | |
| 28 { | |
| 29 } | |
| 30 | |
| 31 nsresult | |
| 32 nsUUIDGenerator::Init() | |
| 33 { | |
| 34 // We're a service, so we're guaranteed that Init() is not going | |
| 35 // to be reentered while we're inside Init(). | |
| 36 | |
| 37 #if !defined(XP_WIN) && !defined(XP_MACOSX) && !defined(ANDROID) | |
| 38 /* initialize random number generator using NSPR random noise */ | |
| 39 unsigned int seed; | |
| 40 | |
| 41 size_t bytes = 0; | |
| 42 while (bytes < sizeof(seed)) { | |
| 43 size_t nbytes = PR_GetRandomNoise(((unsigned char *)&seed)+bytes, | |
| 44 sizeof(seed)-bytes); | |
| 45 if (nbytes == 0) { | |
| 46 return NS_ERROR_FAILURE; | |
| 47 } | |
| 48 bytes += nbytes; | |
| 49 } | |
| 50 | |
| 51 /* Initialize a new RNG state, and immediately switch | |
| 52 * back to the previous one -- we want to use mState | |
| 53 * only for our own calls to random(). | |
| 54 */ | |
| 55 mSavedState = initstate(seed, mState, sizeof(mState)); | |
| 56 setstate(mSavedState); | |
| 57 | |
| 58 mRBytes = 4; | |
| 59 #ifdef RAND_MAX | |
| 60 if ((unsigned long) RAND_MAX < (unsigned long)0xffffffff) | |
| 61 mRBytes = 3; | |
| 62 if ((unsigned long) RAND_MAX < (unsigned long)0x00ffffff) | |
| 63 mRBytes = 2; | |
| 64 if ((unsigned long) RAND_MAX < (unsigned long)0x0000ffff) | |
| 65 mRBytes = 1; | |
| 66 if ((unsigned long) RAND_MAX < (unsigned long)0x000000ff) | |
| 67 return NS_ERROR_FAILURE; | |
| 68 #endif | |
| 69 | |
| 70 #endif /* non XP_WIN and non XP_MACOSX */ | |
| 71 | |
| 72 return NS_OK; | |
| 73 } | |
| 74 | |
| 75 NS_IMETHODIMP | |
| 76 nsUUIDGenerator::GenerateUUID(nsID** ret) | |
| 77 { | |
| 78 nsID *id = static_cast<nsID*>(NS_Alloc(sizeof(nsID))); | |
| 79 if (id == nullptr) | |
| 80 return NS_ERROR_OUT_OF_MEMORY; | |
| 81 | |
| 82 nsresult rv = GenerateUUIDInPlace(id); | |
| 83 if (NS_FAILED(rv)) { | |
| 84 NS_Free(id); | |
| 85 return rv; | |
| 86 } | |
| 87 | |
| 88 *ret = id; | |
| 89 return rv; | |
| 90 } | |
| 91 | |
| 92 NS_IMETHODIMP | |
| 93 nsUUIDGenerator::GenerateUUIDInPlace(nsID* id) | |
| 94 { | |
| 95 // The various code in this method is probably not threadsafe, so lock | |
| 96 // across the whole method. | |
| 97 MutexAutoLock lock(mLock); | |
| 98 | |
| 99 #if defined(XP_WIN) | |
| 100 HRESULT hr = CoCreateGuid((GUID*)id); | |
| 101 if (FAILED(hr)) | |
| 102 return NS_ERROR_FAILURE; | |
| 103 #elif defined(XP_MACOSX) | |
| 104 CFUUIDRef uuid = CFUUIDCreate(kCFAllocatorDefault); | |
| 105 if (!uuid) | |
| 106 return NS_ERROR_FAILURE; | |
| 107 | |
| 108 CFUUIDBytes bytes = CFUUIDGetUUIDBytes(uuid); | |
| 109 memcpy(id, &bytes, sizeof(nsID)); | |
| 110 | |
| 111 CFRelease(uuid); | |
| 112 #else /* not windows or OS X; generate randomness using random(). */ | |
| 113 /* XXX we should be saving the return of setstate here and switching | |
| 114 * back to it; instead, we use the value returned when we called | |
| 115 * initstate, since older glibc's have broken setstate() return values | |
| 116 */ | |
| 117 #ifndef ANDROID | |
| 118 setstate(mState); | |
| 119 #endif | |
| 120 | |
| 121 size_t bytesLeft = sizeof(nsID); | |
| 122 while (bytesLeft > 0) { | |
| 123 #ifdef ANDROID | |
| 124 long rval = arc4random(); | |
| 125 const size_t mRBytes = 4; | |
| 126 #else | |
| 127 long rval = random(); | |
| 128 #endif | |
| 129 | |
| 130 | |
| 131 uint8_t *src = (uint8_t*)&rval; | |
| 132 // We want to grab the mRBytes least significant bytes of rval, since | |
| 133 // mRBytes less than sizeof(rval) means the high bytes are 0. | |
| 134 #ifdef IS_BIG_ENDIAN | |
| 135 src += sizeof(rval) - mRBytes; | |
| 136 #endif | |
| 137 uint8_t *dst = ((uint8_t*) id) + (sizeof(nsID) - bytesLeft); | |
| 138 size_t toWrite = (bytesLeft < mRBytes ? bytesLeft : mRBytes); | |
| 139 for (size_t i = 0; i < toWrite; i++) | |
| 140 dst[i] = src[i]; | |
| 141 | |
| 142 bytesLeft -= toWrite; | |
| 143 } | |
| 144 | |
| 145 /* Put in the version */ | |
| 146 id->m2 &= 0x0fff; | |
| 147 id->m2 |= 0x4000; | |
| 148 | |
| 149 /* Put in the variant */ | |
| 150 id->m3[0] &= 0x3f; | |
| 151 id->m3[0] |= 0x80; | |
| 152 | |
| 153 #ifndef ANDROID | |
| 154 /* Restore the previous RNG state */ | |
| 155 setstate(mSavedState); | |
| 156 #endif | |
| 157 #endif | |
| 158 | |
| 159 return NS_OK; | |
| 160 } |
