Move Source/WTF/wtf to Source/wtf

Source/WTF/wtf/CryptographicallyRandomNumber.cpp

-/*
- * Copyright (c) 1996, David Mazieres <dm@uun.org>
- * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-/*
- * Arc4 random number generator for OpenBSD.
- *
- * This code is derived from section 17.1 of Applied Cryptography,
- * second edition, which describes a stream cipher allegedly
- * compatible with RSA Labs "RC4" cipher (the actual description of
- * which is a trade secret).  The same algorithm is used as a stream
- * cipher called "arcfour" in Tatu Ylonen's ssh package.
- *
- * RC4 is a registered trademark of RSA Laboratories.
- */
-
-#include "config.h"
-#include "CryptographicallyRandomNumber.h"
-
-#include "OSRandomSource.h"
-#include "StdLibExtras.h"
-#include "ThreadingPrimitives.h"
-
-namespace WTF {
-
-#if USE(OS_RANDOMNESS)
-
-namespace {
-
-class ARC4Stream {
-public:
-    ARC4Stream();
-
-    uint8_t i;
-    uint8_t j;
-    uint8_t s[256];
-};
-
-class ARC4RandomNumberGenerator {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    ARC4RandomNumberGenerator();
-
-    uint32_t randomNumber();
-    void randomValues(void* buffer, size_t length);
-
-private:
-    inline void addRandomData(unsigned char *data, int length);
-    void stir();
-    void stirIfNeeded();
-    inline uint8_t getByte();
-    inline uint32_t getWord();
-
-    ARC4Stream m_stream;
-    int m_count;
-    Mutex m_mutex;
-};
-
-ARC4Stream::ARC4Stream()
-{
-    for (int n = 0; n < 256; n++)
-        s[n] = n;
-    i = 0;
-    j = 0;
-}
-
-ARC4RandomNumberGenerator::ARC4RandomNumberGenerator()
-    : m_count(0)
-{
-}
-
-void ARC4RandomNumberGenerator::addRandomData(unsigned char* data, int length)
-{
-    m_stream.i--;
-    for (int n = 0; n < 256; n++) {
-        m_stream.i++;
-        uint8_t si = m_stream.s[m_stream.i];
-        m_stream.j += si + data[n % length];
-        m_stream.s[m_stream.i] = m_stream.s[m_stream.j];
-        m_stream.s[m_stream.j] = si;
-    }
-    m_stream.j = m_stream.i;
-}
-
-void ARC4RandomNumberGenerator::stir()
-{
-    unsigned char randomness[128];
-    size_t length = sizeof(randomness);
-    cryptographicallyRandomValuesFromOS(randomness, length);
-    addRandomData(randomness, length);
-
-    // Discard early keystream, as per recommendations in:
-    // http://www.wisdom.weizmann.ac.il/~itsik/RC4/Papers/Rc4_ksa.ps
-    for (int i = 0; i < 256; i++)
-        getByte();
-    m_count = 1600000;
-}
-
-void ARC4RandomNumberGenerator::stirIfNeeded()
-{
-    if (m_count <= 0)
-        stir();
-}
-
-uint8_t ARC4RandomNumberGenerator::getByte()
-{
-    m_stream.i++;
-    uint8_t si = m_stream.s[m_stream.i];
-    m_stream.j += si;
-    uint8_t sj = m_stream.s[m_stream.j];
-    m_stream.s[m_stream.i] = sj;
-    m_stream.s[m_stream.j] = si;
-    return (m_stream.s[(si + sj) & 0xff]);
-}
-
-uint32_t ARC4RandomNumberGenerator::getWord()
-{
-    uint32_t val;
-    val = getByte() << 24;
-    val |= getByte() << 16;
-    val |= getByte() << 8;
-    val |= getByte();
-    return val;
-}
-
-uint32_t ARC4RandomNumberGenerator::randomNumber()
-{
-    MutexLocker locker(m_mutex);
-
-    m_count -= 4;
-    stirIfNeeded();
-    return getWord();
-}
-
-void ARC4RandomNumberGenerator::randomValues(void* buffer, size_t length)
-{
-    MutexLocker locker(m_mutex);
-
-    unsigned char* result = reinterpret_cast<unsigned char*>(buffer);
-    stirIfNeeded();
-    while (length--) {
-        m_count--;
-        stirIfNeeded();
-        result[length] = getByte();
-    }
-}
-
-ARC4RandomNumberGenerator& sharedRandomNumberGenerator()
-{
-    DEFINE_STATIC_LOCAL(ARC4RandomNumberGenerator, randomNumberGenerator, ());
-    return randomNumberGenerator;
-}
-
-}
-
-uint32_t cryptographicallyRandomNumber()
-{
-    return sharedRandomNumberGenerator().randomNumber();
-}
-
-void cryptographicallyRandomValues(void* buffer, size_t length)
-{
-    sharedRandomNumberGenerator().randomValues(buffer, length);
-}
-
-#endif
-
-}