1 /* 2 * Copyright (C) 2010 Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * * Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * * Redistributions in binary form must reproduce the above 11 * copyright notice, this list of conditions and the following disclaimer 12 * in the documentation and/or other materials provided with the 13 * distribution. 14 * * Neither the name of Google Inc. nor the names of its 15 * contributors may be used to endorse or promote products derived from 16 * this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include "config.h" 32 #include "core/platform/UUID.h" 33 34 #include "wtf/CryptographicallyRandomNumber.h" 35 #include "wtf/HexNumber.h" 36 #include "wtf/text/StringBuilder.h" 37 38 namespace WebCore { 39 40 String createCanonicalUUIDString() 41 { 42 unsigned randomData[4]; 43 cryptographicallyRandomValues(reinterpret_cast<unsigned char*>(randomData), sizeof(randomData)); 44 45 // Format as Version 4 UUID. 46 StringBuilder builder; 47 builder.reserveCapacity(36); 48 appendUnsignedAsHexFixedSize(randomData[0], builder, 8, Lowercase); 49 builder.append("-"); 50 appendUnsignedAsHexFixedSize(randomData[1] >> 16, builder, 4, Lowercase); 51 builder.append("-4"); 52 appendUnsignedAsHexFixedSize(randomData[1] & 0x00000fff, builder, 3, Lowercase); 53 builder.append("-"); 54 appendUnsignedAsHexFixedSize((randomData[2] >> 30) | 0x8, builder, 1, Lowercase); 55 appendUnsignedAsHexFixedSize((randomData[2] >> 16) & 0x00000fff, builder, 3, Lowercase); 56 builder.append("-"); 57 appendUnsignedAsHexFixedSize(randomData[2] & 0x0000ffff, builder, 4, Lowercase); 58 appendUnsignedAsHexFixedSize(randomData[3], builder, 8, Lowercase); 59 return builder.toString(); 60 } 61 62 } 63
