package net.i2p.util;
/*
* free (adj.): unencumbered; not under the control of others
* Written by jrandom in 2003 and released into the public domain
* with no warranty of any kind, either expressed or implied.
* It probably won't make your computer catch on fire, or eat
* your children, but it might. Use at your own risk.
*
*/
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
import java.net.URL;
import java.util.Random;
import freenet.support.CPUInformation.AMDCPUInfo;
import freenet.support.CPUInformation.CPUID;
import freenet.support.CPUInformation.CPUInfo;
import freenet.support.CPUInformation.IntelCPUInfo;
import freenet.support.CPUInformation.UnknownCPUException;
/**
* <p>BigInteger that takes advantage of the jbigi library for the modPow operation,
* which accounts for a massive segment of the processing cost of asymmetric
* crypto. It also takes advantage of the jbigi library for converting a BigInteger
* value to a double. Sun/Oracle's implementation of the 'doubleValue()' method is _very_ lousy.
*
* The jbigi library itself is basically just a JNI wrapper around the
* GMP library - a collection of insanely efficient routines for dealing with
* big numbers.</p>
*
* There are three environmental properties for configuring this component: <ul>
* <li><b>jbigi.enable</b>: whether to use the native library (defaults to "true")</li>
* <li><b>jbigi.impl</b>: select which resource to use as the native implementation</li>
* <li><b>jbigi.ref</b>: the file specified in this parameter may contain a resource
* name to override jbigi.impl (defaults to "jbigi.cfg")</li>
* </ul>
*
* <p>If jbigi.enable is set to false, this class won't even attempt to use the
* native library, but if it is set to true (or is not specified), it will first
* check the platform specific library path for the "jbigi" library, as defined by
* {@link Runtime#loadLibrary} - e.g. C:\windows\jbigi.dll or /lib/libjbigi.so.
* If that fails, it reviews the jbigi.impl environment property - if that is set,
* it checks all of the components in the CLASSPATH for the file specified and
* attempts to load it as the native library. If jbigi.impl is not set, if there
* is no matching resource, or if that resource is not a valid OS/architecture
* specific library, the NativeBigInteger will revert to using the pure java
* implementation.</p>
*
* <p>That means <b>NativeBigInteger will not attempt to guess the correct
* platform/OS/whatever</b> - applications using this class should define that
* property prior to <i>referencing</i> the NativeBigInteger (or before loading
* the JVM, of course). Alternately, people with custom built jbigi implementations
* in their OS's standard search path (LD_LIBRARY_PATH, etc) needn't bother.</p>
*
* <p>One way to deploy the native library is to create a jbigi.jar file containing
* all of the native implementations with filenames such as "win-athlon", "linux-p2",
* "freebsd-sparcv4", where those files are the OS specific libraries (the contents of
* the DLL or .so file built for those OSes / architectures). The user would then
* simply specify -Djbigi.impl=win-athlon and this component would pick up that
* library.</p>
*
* <p>Another way is to create a separate jbigi.jar file for each platform containing
* one file - "native", where that file is the OS / architecture specific library
* implementation, as above. This way the user would download the correct jbigi.jar
* (and not all of the libraries for platforms/OSes they don't need) and would specify
* -Djbigi.impl=native.</p>
*
* <p>Running this class by itself does a basic unit test and benchmarks the
* NativeBigInteger.modPow/doubleValue vs. the BigInteger.modPow/doubleValue by running a 2Kbit op 100
* times. At the end of each test, if the native implementation is loaded this will output
* something like:</p>
* <pre>
* native run time: 6090ms (60ms each)
* java run time: 68067ms (673ms each)
* native = 8.947066860593239% of pure java time
* </pre>
*
* <p>If the native implementation is not loaded, it will start by saying:</p>
* <pre>
* WARN: Native BigInteger library jbigi not loaded - using pure java
* </pre>
* <p>Then go on to run the test, finally outputting:</p>
* <pre>
* java run time: 64653ms (640ms each)
* However, we couldn't load the native library, so this doesn't test much
* </pre>
*
*/
public class NativeBigInteger extends BigInteger {
/** did we load the native lib correctly? */
private static boolean _nativeOk = false;
/**
* do we want to dump some basic success/failure info to stderr during
* initialization? this would otherwise use the Log component, but this makes
* it easier for other systems to reuse this class
*/
private static final boolean _doLog = true;
private final static String JBIGI_OPTIMIZATION_ARM = "arm";
private final static String JBIGI_OPTIMIZATION_K6 = "k6";
private final static String JBIGI_OPTIMIZATION_K6_2 = "k62";
private final static String JBIGI_OPTIMIZATION_K6_3 = "k63";
private final static String JBIGI_OPTIMIZATION_ATHLON = "athlon";
private final static String JBIGI_OPTIMIZATION_X86_64 = "x86_64";
private final static String JBIGI_OPTIMIZATION_X86_64_32 = "x86_64_32";
private final static String JBIGI_OPTIMIZATION_PENTIUM = "pentium";
private final static String JBIGI_OPTIMIZATION_PENTIUMMMX = "pentiummmx";
private final static String JBIGI_OPTIMIZATION_PENTIUM2 = "pentium2";
private final static String JBIGI_OPTIMIZATION_PENTIUM3 = "pentium3";
private final static String JBIGI_OPTIMIZATION_PENTIUM4 = "pentium4";
private final static String JBIGI_OPTIMIZATION_PPC = "ppc";
private final static String sCPUType; //The CPU Type to optimize for (one of the above strings)
private static final long serialVersionUID = 0xc5392a97bb283dd2L;
static {
sCPUType = resolveCPUType();
loadNative();
}
/** Tries to resolve the best type of CPU that we have an optimized jbigi-dll/so for.
* @return A string containing the CPU-type or null if CPU type is unknown
*/
private static String resolveCPUType() {
try {
String _os_arch = System.getProperty("os.arch").toLowerCase();
if(System.getProperty("os.arch").toLowerCase().matches("(i?[x0-9]86_64|amd64)")
// 32-bit JVM on a 64-bit system is common, in which case can't load 64-bit libraries, so ignore.
&& System.getProperty("sun.arch.data.model").equals("64"))
{
return JBIGI_OPTIMIZATION_X86_64;
} else if(_os_arch.matches("(arm)"))
{
System.out.println("Detected ARM!");
return JBIGI_OPTIMIZATION_ARM;
} else if(_os_arch.matches("(ppc)"))
{
System.out.println("Detected PowerPC!");
return JBIGI_OPTIMIZATION_PPC;
} else {
CPUInfo c = CPUID.getInfo();
if(c instanceof AMDCPUInfo) {
AMDCPUInfo amdcpu = (AMDCPUInfo) c;
if(amdcpu.IsAthlon64Compatible())
return JBIGI_OPTIMIZATION_X86_64_32;
if(amdcpu.IsAthlonCompatible())
return JBIGI_OPTIMIZATION_ATHLON;
if(amdcpu.IsK6_3_Compatible())
return JBIGI_OPTIMIZATION_K6_3;
if(amdcpu.IsK6_2_Compatible())
return JBIGI_OPTIMIZATION_K6_2;
if(amdcpu.IsK6Compatible())
return JBIGI_OPTIMIZATION_K6;
} else
if(c instanceof IntelCPUInfo) {
IntelCPUInfo intelcpu = (IntelCPUInfo) c;
if(intelcpu.IsPentium4Compatible())
return JBIGI_OPTIMIZATION_PENTIUM4;
if(intelcpu.IsPentium3Compatible())
return JBIGI_OPTIMIZATION_PENTIUM3;
if(intelcpu.IsPentium2Compatible())
return JBIGI_OPTIMIZATION_PENTIUM2;
if(intelcpu.IsPentiumMMXCompatible())
return JBIGI_OPTIMIZATION_PENTIUMMMX;
if(intelcpu.IsPentiumCompatible())
return JBIGI_OPTIMIZATION_PENTIUM;
}
}
return null;
} catch(UnknownCPUException e) {
return null; //TODO: Log something here maybe..
}
}
/**
* calculate (base ^ exponent) % modulus.
*
* @param base
* big endian twos complement representation of the base (but it must be positive)
* @param exponent
* big endian twos complement representation of the exponent
* @param modulus
* big endian twos complement representation of the modulus
* @return big endian twos complement representation of (base ^ exponent) % modulus
*/
public native static byte[] nativeModPow(byte base[], byte exponent[], byte modulus[]);
/**
* Converts a BigInteger byte-array to a 'double'
* @param ba Big endian twos complement representation of the BigInteger to convert to a double
* @return The plain double-value represented by 'ba'
*/
public native static double nativeDoubleValue(byte ba[]);
private byte[] cachedBa = null;
/**
*
* @param val
*/
public NativeBigInteger(byte val[]) {
super(val);
// Takes up too much RAM
// int targetLength = bitLength() / 8 + 1;
// if(val.length == targetLength)
// cachedBa = val;
}
/**
*
* @param signum
* @param magnitude
*/
public NativeBigInteger(int signum, byte magnitude[]) {
super(signum, magnitude);
}
/**
*
* @param bitlen
* @param certainty
* @param rnd
*/
public NativeBigInteger(int bitlen, int certainty, Random rnd) {
super(bitlen, certainty, rnd);
}
/**
*
* @param numbits
* @param rnd
*/
public NativeBigInteger(int numbits, Random rnd) {
super(numbits, rnd);
}
/**
*
* @param val
*/
public NativeBigInteger(String val) {
super(val);
}
/**
*
* @param val
* @param radix
*/
public NativeBigInteger(String val, int radix) {
super(val, radix);
}
/**Creates a new NativeBigInteger with the same value
* as the supplied BigInteger. Warning!, not very efficient
*
* @param integer
*/
public NativeBigInteger(BigInteger integer) {
//Now, why doesn't Sun/Oracle provide a constructor
//like this one in BigInteger?
this(integer.toByteArray());
}
@Override
public BigInteger modPow(BigInteger exponent, BigInteger m) {
if(_nativeOk)
return new NativeBigInteger(nativeModPow(toByteArray(), exponent.toByteArray(), m.toByteArray()));
else
return new NativeBigInteger(super.modPow(exponent, m));
}
@Override
public byte[] toByteArray() {
if(cachedBa == null) //Since we are immutable it is safe to never update the cached ba after it has initially been generated
cachedBa = super.toByteArray();
return cachedBa;
}
@Override
public double doubleValue() {
// TODO Recent tests show that Java version is quicker. Maybe drop?
if(_nativeOk)
return nativeDoubleValue(toByteArray());
else
return super.doubleValue();
}
/**
*
* @return True if native methods will be used by this class
*/
public static boolean isNative() {
return _nativeOk;
}
/**
* <p>Do whatever we can to load up the native library backing this BigInteger's native methods.
* If it can find a custom built jbigi.dll / libjbigi.so, it'll use that. Otherwise
* it'll try to look in the classpath for the correct library (see loadFromResource).
* If the user specifies -Djbigi.enable=false it'll skip all of this.</p>
*
* FIXME: Is it a good idea to load it from the path? Shouldn't we not trust the path?
*/
private static void loadNative() {
try {
String wantedProp = System.getProperty("jbigi.enable", "true");
boolean wantNative = "true".equalsIgnoreCase(wantedProp);
if(wantNative) {
boolean loaded = loadFromResource(true);
if(loaded) {
_nativeOk = true;
if(_doLog)
System.err.println("INFO: Optimized native BigInteger library '" + getResourceName(true) + "' loaded from resource");
} else {
loaded = loadGeneric(true);
if(loaded) {
_nativeOk = true;
if(_doLog)
System.err.println("INFO: Optimized native BigInteger library '" + getMiddleName(true) + "' loaded from somewhere in the path");
} else {
loaded = loadFromResource(false);
if(loaded) {
_nativeOk = true;
if(_doLog)
System.err.println("INFO: Non-optimized native BigInteger library '" + getResourceName(false) + "' loaded from resource");
} else {
loaded = loadGeneric(false);
if(loaded) {
_nativeOk = true;
if(_doLog)
System.err.println("INFO: Non-optimized native BigInteger library '" + getMiddleName(false) + "' loaded from somewhere in the path");
} else
_nativeOk = false;
}
}
}
}
if(_doLog && !_nativeOk)
System.err.println("INFO: Native BigInteger library jbigi not loaded - using pure java");
} catch(Throwable e) {
if(_doLog)
System.err.println("INFO: Native BigInteger library jbigi not loaded, reason: '" + e.getMessage() + "' - using pure java");
}
}
/**
* <p>Try loading it from an explicitly build jbigi.dll / libjbigi.so first, before
* looking into a jbigi.jar for any other libraries.</p>
*
* @return true if it was loaded successfully, else false
*
*/
private static boolean loadGeneric(boolean optimized) {
try {
String name = getMiddleName(optimized);
if(name == null)
return false;
System.loadLibrary(name);
return true;
} catch(UnsatisfiedLinkError ule) {
return false;
}
}
/**
* A helper function to make loading the native library easier.
* @param f The File to which to write the library
* @param URL The URL of the resource
* @return True is the library was loaded, false on error
* @throws FileNotFoundException If the library could not be read from the reference
* @throws UnsatisfiedLinkError If and only if the library is incompatible with this system
*/
private static boolean tryLoadResource(File f, URL resource)
throws FileNotFoundException, UnsatisfiedLinkError {
InputStream is;
try {
is = resource.openStream();
} catch(IOException e) {
f.delete();
throw new FileNotFoundException();
}
FileOutputStream fos = null;
try {
f.deleteOnExit();
fos = new FileOutputStream(f);
byte[] buf = new byte[4096 * 1024];
int read;
while((read = is.read(buf)) > 0) {
fos.write(buf, 0, read);
}
fos.close();
fos = null;
System.load(f.getAbsolutePath());
return true;
} catch(IOException e) {
} catch(UnsatisfiedLinkError ule) {
// likely to be "noexec"
if(ule.toString().toLowerCase().indexOf("not permitted") == -1)
throw ule;
} finally {
if (fos != null) { try { fos.close(); } catch (IOException e) { /* ignore */ } }
f.delete();
}
return false;
}
/**
* <p>Check all of the jars in the classpath for the file specified by the
* environmental property "jbigi.impl" and load it as the native library
* implementation. For instance, a windows user on a p4 would define
* -Djbigi.impl=win-686 if there is a jbigi.jar in the classpath containing the
* files "win-686", "win-athlon", "freebsd-p4", "linux-p3", where each
* of those files contain the correct binary file for a native library (e.g.
* windows DLL, or a *nix .so). </p>
*
* <p>This is a pretty ugly hack, using the general technique illustrated by the
* onion FEC libraries. It works by pulling the resource, writing out the
* byte stream to a temporary file, loading the native library from that file,
* then deleting the file.</p>
*
* @return true if it was loaded successfully, else false
*
*/
private static boolean loadFromResource(boolean optimized) {
String resourceName = getResourceName(optimized);
if(resourceName == null)
return false;
URL resource = NativeBigInteger.class.getClassLoader().getResource(resourceName);
if(resource == null) {
if(_doLog)
System.err.println("NOTICE: Resource name [" + getResourceName(true) + "] was not found");
return false;
}
File temp = null;
try {
try {
temp = File.createTempFile("jbigi", "lib.tmp");
if(tryLoadResource(temp, resource))
return true;
} catch(IOException e) {
} finally {
if(temp != null) temp.delete();
}
System.err.println("net.i2p.util.NativeBigInteger: Can't load from " + System.getProperty("java.io.tmpdir"));
temp = new File("jbigi-lib.tmp");
if(tryLoadResource(temp, resource))
return true;
} catch(Exception fnf) {
System.err.println("net.i2p.util.NativeBigInteger: Error reading jbigi resource");
} catch(UnsatisfiedLinkError ule) {
System.err.println("net.i2p.util.NativeBigInteger: Library " + resourceName + " is not appropriate for this system.");
} finally {
if(temp != null) temp.delete();
}
return false;
}
private static String getResourceName(boolean optimized) {
String name = NativeBigInteger.class.getName();
int i = name.lastIndexOf('.');
if (i != -1) {
name = name.substring(0, i);
}
String pname = name.replace('.', '/');
String pref = getLibraryPrefix();
String middle = getMiddleName(optimized);
String suff = getLibrarySuffix();
if((pref == null) || (middle == null) || (suff == null))
return null;
return pname + '/' + pref + middle + '.' + suff;
}
private static String getMiddleName(boolean optimized) {
String sAppend;
if(optimized)
if(sCPUType == null)
return null;
else
sAppend = '-' + sCPUType;
else
sAppend = "-none";
boolean isWindows = (System.getProperty("os.name").toLowerCase().indexOf("windows") != -1);
boolean isLinux = (System.getProperty("os.name").toLowerCase().indexOf("linux") != -1);
boolean isFreebsd = (System.getProperty("os.name").toLowerCase().indexOf("freebsd") != -1);
boolean isMacOS = (System.getProperty("os.name").toLowerCase().indexOf("mac os x") != -1);
if(isWindows)
return "jbigi-windows" + sAppend; // The convention on Windows
if(isLinux)
return "jbigi-linux" + sAppend; // The convention on linux...
if(isFreebsd)
return "jbigi-freebsd" + sAppend; // The convention on freebsd...
if(isMacOS)
return "jbigi-osx" + sAppend; // The convention on Mac OS X...
throw new RuntimeException("Dont know jbigi library name for os type '" + System.getProperty("os.name") + '\'');
}
private static String getLibrarySuffix() {
boolean isWindows = System.getProperty("os.name").toLowerCase().indexOf("windows") != -1;
boolean isMacOS = (System.getProperty("os.name").toLowerCase().indexOf("mac os x") != -1);
if(isWindows)
return "dll";
else if(isMacOS)
return "jnilib";
else
return "so";
}
private static String getLibraryPrefix() {
boolean isWindows = System.getProperty("os.name").toLowerCase().indexOf("windows") != -1;
if(isWindows)
return "";
else
return "lib";
}
}