我有一个为Windows编写的C++代码(Visual Studio),我需要将它移植到Java中。这不是很容易,目前我被困在使用正弦函数。来自Linux(经过测试以进行比较)和Java的结果与Windows源的结果不同。两个结果都是错误的,但这并不重要。结果是完全一样的,这很重要。微软和Java/Linux之间正弦函数的结果不同
我会在底部发布整个源代码。例如,我需要计算5174852443848405000.0的正弦值。我知道这是一个非常大的,也许是不寻常的数字,但我不能改变这一点。 Linux和Java返回0.153662和Windows约0.16xx。 函数“random_value_genrator()”被使用大约500,000次,因此结果的差异可能稍后会发生。
initial_value_generator将计算稍后由random_value_generator函数使用的值。该值由FILETIME对象和三个常量生成。缓冲区溢出正在发生但未处理。 random_value_generator每次使用时都会修改DWORD64 prng_initial_value。
我能够成功构建initial_value_generator函数。
我想我不能完成这个任务,但任何帮助表示赞赏。
有些全局变量:
DWORD64 prng_initial_value = 0;
DWORD64 CON1_RVG = 0x4F3D859E;
double CON2_RVG = 0.946270391;
DWORD64 CON1_PRNG = 0x2682D10B7;
DWORD64 CON2_PRNG = 0x19254D38000;
DWORD64 CON3_PRNG = 0x0F1E34A09;
此功能在程序启动时使用一次。将一个较大的DWORD64写入prng_initial_value,稍后由random_value_generator()使用。 的系统时间是由常数1(缓冲区溢出)相乘,由常数除以2,并用恒定3.
void initial_value_generator()
{
SYSTEMTIME systime;
FILETIME filetime;
// Systemzeit zu GMT-Format umwandeln
SystemTimeToFileTime(&systime,&filetime);
prng_initial_value = (*(DWORD64*)&filetime) * CON1_PRNG/CON2_PRNG + CON3_PRNG;
}
此功能在每次使用时改变所述DWORD64 prng_initial_value加入。
int random_value_generator()
{
double sin_value;
double copy_of_prng_initial_value;
DWORD64 prng_con1;
double result;
// Initialen Wert aus dem initial_random_generator in lokaler Variable speichern
copy_of_prng_initial_value = prng_initial_value;
// Sinus vom initialen Wert
sin_value = sin(copy_of_prng_initial_value);
// Initialen Wert mulipikation mit einem konstanten Wert (0x4F3D859E)
prng_con1 = prng_initial_value * CON1_RVG;
一些进一步的计算变得疯狂:
result = prng_con1 + sin_value;
result = result * copy_of_prng_initial_value;
result = result + CON2_RVG;
result = result * copy_of_prng_initial_value;
// Das Ergebnis aus der Logarithmus Rechnung addieren
result += log(copy_of_prng_initial_value);
// Das Ergebnis aus den Berechnungen als Pointer in die
// Speicheradresse von prng_initial_value als double Pointer speichern.
*(double*)&prng_initial_value = result;
// Rueckgabe des Berechneten Wert als Integer
return prng_initial_value;
}
仅供参考我发表我的Java代码(所有评论都是英文)。随机函数看起来有点疯狂,因为我正在测试很多东西。我对此非常抱歉。但重要的一点是Math.sin(double x)函数的使用,其结果与使用Microsoft C++编译器的Math.h中的sin函数不同。
private final long initialValue;
private long randomValue;
final BigInteger uint64MaxValue = new BigInteger("18446744073709551616"); //2^64
public ConfickerC() {
this.initialValue = this.generateInitialValue();
this.randomValue = this.initialValue;
}
private long generateInitialValue() {
//We need the actual date without the time from GMT +0 timezone
Calendar cal = Calendar.getInstance(TimeZone.getTimeZone("GMT"));
cal.set(Calendar.HOUR_OF_DAY, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
long systemtimeAsFiletime = cal.getTimeInMillis();
/*
* Goal is to get the above created date into Windows FileTime format.
* The Windows FileTime format has got 100 nano seconds per tick.
* So one increment of the long value results further 100 nano seconds.
* Instead of Unix the FileTime format begins with 1st January 1601 - not 1970.
* 11644473600 is the interval between 1601 and 1970 in seconds.
* Java has got a resolution of 1 ms per tick unix have got 1 second per
* tick. So first devide the time by 1000. Then add the interval.
* After this we multiply by 10 million to get a resolution of 100
* nano seconds per tick.
*/
systemtimeAsFiletime /= 1000; //divide by 1000 to get seconds instead of milliseconds
systemtimeAsFiletime += 11644473600L; //add x seconds to add the interval between 1601 and 1970
systemtimeAsFiletime *= 10000000L; //Windows FileTime has a resolution of 100 nano seconds per tick; so multiply by 10M
/*
* The virus is calulating for getting the initial value: time * con1/con2 + con3
* Originaly there occurs a buffer overflow which is not handled in the C++ code.
* The funny thing is that Java does not have a DWORD64 (unsinged _int64). So because of this bit missing (and so the overflow is different) we need BigInteger.
* Because BigInteger has no 2^64 limitation we need the maximul value of DWORD64.
* This is used to "simulate" the buffer overflow by calculating ((time * con1) % 2^64)/con2 + con3
* modulo 2^64 will result a value which is equal to the C++ calculation
*/
final BigInteger CONSTANT_1 = new BigInteger("10337718455"); //Original: 0x2682D10B7
final BigInteger CONSTANT_2 = new BigInteger("1728000000000"); //Original: 0x19254D38000
final BigInteger CONSTANT_3 = new BigInteger("4058204681"); //Original: 0x0F1E34A09
BigInteger bigIntSystemTime = BigInteger.valueOf(systemtimeAsFiletime);
//Return as long value: ((time * con1) % 2^64)/con2 + con3
return bigIntSystemTime.multiply(CONSTANT_1).divideAndRemainder(uint64MaxValue)[1].divide(CONSTANT_2).add(CONSTANT_3).longValue();
}
private int generateRandomValue() {
final long CONSTANT_1 = 1329431966L;
final double CONSTANT_2 = 0.946270391;
double result = 0.0;
double copyOfInit = this.randomValue;
System.out.println(System.getProperty("line.separator") + "Copy of init: " + copyOfInit);
System.out.printf("Copy of init: %f\n", copyOfInit);
double sinInit = Math.sin(copyOfInit); System.out.println("Sinus: " + sinInit);
System.out.printf("Sinus: %f\n", sinInit);
System.out.println("Sinus gerundet: " + Math.round(sinInit*1000000)/1000000.0d);
BigInteger b = BigInteger.valueOf(this.randomValue).multiply(BigInteger.valueOf(CONSTANT_1)).divideAndRemainder(uint64MaxValue)[1];
System.out.println("Init * Konstante 1: " + b);
BigDecimal bd = new BigDecimal(b.toString());
//bd.add(BigDecimal.valueOf(sinInit));
//result = t + sinInit; System.out.println("Multi + Sinus: " + result);
result = bd.add(BigDecimal.valueOf(sinInit)).doubleValue(); System.out.println("Multi + Sinus: " + result);
result *= (long) this.randomValue; System.out.println("Zwischenergebnis * init: " + result);
result += CONSTANT_2; System.out.println("Konstante 2 addiert: " + result);
System.out.printf("BigD: %s", BigDecimal.valueOf(result).multiply(BigDecimal.valueOf(randomValue)));
result *= this.randomValue; System.out.printf("Erneut mit init multipliziert: %f", result);
double l = Math.log((long)this.randomValue); System.out.println("Log von init: " + l);
result += l; System.out.printf("+= mit Log: %f\n", result);
this.randomValue = (long)result; System.out.printf("Ende: %d\n", this.randomValue);
this.randomValue = Double.doubleToRawLongBits(result);
return (int)this.randomValue;
}
这看起来很有趣。你能简化你的代码到复制错误所需的最小数量,以便我们可以排除代码中存在另一个错误的可能性吗? – templatetypedef
@templatetypedef说了什么,SSCCE在这里会很有用。您也可以发布您的Java源代码,以排除在端口过程中不存在错误的可能性。虽然我确信sin(x)的结果可能会因语言不同而不同(由于计算方法稍有不同),但它不应该那么大。 – Radiodef
采取这么大数目的正弦没有意义。正弦值仅在[0,2 * PI]范围内有趣。对于所有的值,“sin(x)= sin(x%(2 * PI))”。当你使用这么大的数字时,你已经失去了影响正弦计算值范围内的所有重要性。你需要重新考虑你的算法。 – pburka