michael@0: /* -*- Mode: C++; tab-width: 50; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #if defined(XP_WIN)
michael@0: #include <windows.h>
michael@0: #include <objbase.h>
michael@0: #elif defined(XP_MACOSX)
michael@0: #include <CoreFoundation/CoreFoundation.h>
michael@0: #else
michael@0: #include <stdlib.h>
michael@0: #include "prrng.h"
michael@0: #endif
michael@0: 
michael@0: #include "nsUUIDGenerator.h"
michael@0: 
michael@0: using namespace mozilla;
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(nsUUIDGenerator, nsIUUIDGenerator)
michael@0: 
michael@0: nsUUIDGenerator::nsUUIDGenerator()
michael@0:     : mLock("nsUUIDGenerator.mLock")
michael@0: {
michael@0: }
michael@0: 
michael@0: nsUUIDGenerator::~nsUUIDGenerator()
michael@0: {
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsUUIDGenerator::Init()
michael@0: {
michael@0:     // We're a service, so we're guaranteed that Init() is not going
michael@0:     // to be reentered while we're inside Init().
michael@0:     
michael@0: #if !defined(XP_WIN) && !defined(XP_MACOSX) && !defined(ANDROID)
michael@0:     /* initialize random number generator using NSPR random noise */
michael@0:     unsigned int seed;
michael@0: 
michael@0:     size_t bytes = 0;
michael@0:     while (bytes < sizeof(seed)) {
michael@0:         size_t nbytes = PR_GetRandomNoise(((unsigned char *)&seed)+bytes,
michael@0:                                           sizeof(seed)-bytes);
michael@0:         if (nbytes == 0) {
michael@0:             return NS_ERROR_FAILURE;
michael@0:         }
michael@0:         bytes += nbytes;
michael@0:     }
michael@0: 
michael@0:     /* Initialize a new RNG state, and immediately switch
michael@0:      * back to the previous one -- we want to use mState
michael@0:      * only for our own calls to random().
michael@0:      */
michael@0:     mSavedState = initstate(seed, mState, sizeof(mState));
michael@0:     setstate(mSavedState);
michael@0: 
michael@0:     mRBytes = 4;
michael@0: #ifdef RAND_MAX
michael@0:     if ((unsigned long) RAND_MAX < (unsigned long)0xffffffff)
michael@0:         mRBytes = 3;
michael@0:     if ((unsigned long) RAND_MAX < (unsigned long)0x00ffffff)
michael@0:         mRBytes = 2;
michael@0:     if ((unsigned long) RAND_MAX < (unsigned long)0x0000ffff)
michael@0:         mRBytes = 1;
michael@0:     if ((unsigned long) RAND_MAX < (unsigned long)0x000000ff)
michael@0:         return NS_ERROR_FAILURE;
michael@0: #endif
michael@0: 
michael@0: #endif /* non XP_WIN and non XP_MACOSX */
michael@0: 
michael@0:     return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsUUIDGenerator::GenerateUUID(nsID** ret)
michael@0: {
michael@0:     nsID *id = static_cast<nsID*>(NS_Alloc(sizeof(nsID)));
michael@0:     if (id == nullptr)
michael@0:         return NS_ERROR_OUT_OF_MEMORY;
michael@0: 
michael@0:     nsresult rv = GenerateUUIDInPlace(id);
michael@0:     if (NS_FAILED(rv)) {
michael@0:         NS_Free(id);
michael@0:         return rv;
michael@0:     }
michael@0: 
michael@0:     *ret = id;
michael@0:     return rv;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsUUIDGenerator::GenerateUUIDInPlace(nsID* id)
michael@0: {
michael@0:     // The various code in this method is probably not threadsafe, so lock
michael@0:     // across the whole method.
michael@0:     MutexAutoLock lock(mLock);
michael@0: 
michael@0: #if defined(XP_WIN)
michael@0:     HRESULT hr = CoCreateGuid((GUID*)id);
michael@0:     if (FAILED(hr))
michael@0:         return NS_ERROR_FAILURE;
michael@0: #elif defined(XP_MACOSX)
michael@0:     CFUUIDRef uuid = CFUUIDCreate(kCFAllocatorDefault);
michael@0:     if (!uuid)
michael@0:         return NS_ERROR_FAILURE;
michael@0: 
michael@0:     CFUUIDBytes bytes = CFUUIDGetUUIDBytes(uuid);
michael@0:     memcpy(id, &bytes, sizeof(nsID));
michael@0: 
michael@0:     CFRelease(uuid);
michael@0: #else /* not windows or OS X; generate randomness using random(). */
michael@0:     /* XXX we should be saving the return of setstate here and switching
michael@0:      * back to it; instead, we use the value returned when we called
michael@0:      * initstate, since older glibc's have broken setstate() return values
michael@0:      */
michael@0: #ifndef ANDROID
michael@0:     setstate(mState);
michael@0: #endif
michael@0: 
michael@0:     size_t bytesLeft = sizeof(nsID);
michael@0:     while (bytesLeft > 0) {
michael@0: #ifdef ANDROID
michael@0:         long rval = arc4random();
michael@0:         const size_t mRBytes = 4;
michael@0: #else
michael@0:         long rval = random();
michael@0: #endif
michael@0: 
michael@0: 
michael@0:         uint8_t *src = (uint8_t*)&rval;
michael@0:         // We want to grab the mRBytes least significant bytes of rval, since
michael@0:         // mRBytes less than sizeof(rval) means the high bytes are 0.
michael@0: #ifdef IS_BIG_ENDIAN
michael@0:         src += sizeof(rval) - mRBytes;
michael@0: #endif
michael@0:         uint8_t *dst = ((uint8_t*) id) + (sizeof(nsID) - bytesLeft);
michael@0:         size_t toWrite = (bytesLeft < mRBytes ? bytesLeft : mRBytes);
michael@0:         for (size_t i = 0; i < toWrite; i++)
michael@0:             dst[i] = src[i];
michael@0: 
michael@0:         bytesLeft -= toWrite;
michael@0:     }
michael@0: 
michael@0:     /* Put in the version */
michael@0:     id->m2 &= 0x0fff;
michael@0:     id->m2 |= 0x4000;
michael@0: 
michael@0:     /* Put in the variant */
michael@0:     id->m3[0] &= 0x3f;
michael@0:     id->m3[0] |= 0x80;
michael@0: 
michael@0: #ifndef ANDROID
michael@0:     /* Restore the previous RNG state */
michael@0:     setstate(mSavedState);
michael@0: #endif
michael@0: #endif
michael@0: 
michael@0:     return NS_OK;
michael@0: }