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 "platform/UUID.h"
33
34 #include "wtf/CryptographicallyRandomNumber.h"
35 #include "wtf/HexNumber.h"
36 #include "wtf/text/StringBuilder.h"
37
38 namespace blink {
39
createCanonicalUUIDString()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.appendLiteral("-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