bcprov/src/main/java/org/bouncycastle/crypto/CryptoServicesRegistrar.java - platform/external/bouncycastle - Git at Google

 package org.bouncycastle.crypto;

 import java.math.BigInteger;
 import java.security.AccessController;
 import java.security.Permission;
 import java.security.PrivilegedAction;
 import java.security.SecureRandom;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;

 import org.bouncycastle.asn1.x9.X9ECParameters;
 import org.bouncycastle.crypto.params.DHParameters;
 import org.bouncycastle.crypto.params.DHValidationParameters;
 import org.bouncycastle.crypto.params.DSAParameters;
 import org.bouncycastle.crypto.params.DSAValidationParameters;
 import org.bouncycastle.util.encoders.Hex;

 /**
  * Basic registrar class for providing defaults for cryptography services in this module.
  */
 public final class CryptoServicesRegistrar
 {
     private static final Permission CanSetDefaultProperty = new CryptoServicesPermission(CryptoServicesPermission.GLOBAL_CONFIG);
     private static final Permission CanSetThreadProperty = new CryptoServicesPermission(CryptoServicesPermission.THREAD_LOCAL_CONFIG);
     private static final Permission CanSetDefaultRandom = new CryptoServicesPermission(CryptoServicesPermission.DEFAULT_RANDOM);

     private static final ThreadLocal<Map<String, Object[]>> threadProperties = new ThreadLocal<Map<String, Object[]>>();
     private static final Map<String, Object[]> globalProperties = Collections.synchronizedMap(new HashMap<String, Object[]>());

     private static volatile SecureRandom defaultSecureRandom;

     static
     {
         // default domain parameters for DSA and Diffie-Hellman

         DSAParameters def512Params = new DSAParameters(
             new BigInteger("fca682ce8e12caba26efccf7110e526db078b05edecbcd1eb4a208f3ae1617ae01f35b91a47e6df63413c5e12ed0899bcd132acd50d99151bdc43ee737592e17", 16),
             new BigInteger("962eddcc369cba8ebb260ee6b6a126d9346e38c5", 16),
             new BigInteger("678471b27a9cf44ee91a49c5147db1a9aaf244f05a434d6486931d2d14271b9e35030b71fd73da179069b32e2935630e1c2062354d0da20a6c416e50be794ca4", 16),
             new DSAValidationParameters(Hex.decode("b869c82b35d70e1b1ff91b28e37a62ecdc34409b"), 123));

         DSAParameters def768Params = new DSAParameters(
             new BigInteger("e9e642599d355f37c97ffd3567120b8e25c9cd43e927b3a9670fbec5" +
                            "d890141922d2c3b3ad2480093799869d1e846aab49fab0ad26d2ce6a" +
                            "22219d470bce7d777d4a21fbe9c270b57f607002f3cef8393694cf45" +
                            "ee3688c11a8c56ab127a3daf", 16),
             new BigInteger("9cdbd84c9f1ac2f38d0f80f42ab952e7338bf511", 16),
             new BigInteger("30470ad5a005fb14ce2d9dcd87e38bc7d1b1c5facbaecbe95f190aa7" +
                            "a31d23c4dbbcbe06174544401a5b2c020965d8c2bd2171d366844577" +
                            "1f74ba084d2029d83c1c158547f3a9f1a2715be23d51ae4d3e5a1f6a" +
                            "7064f316933a346d3f529252", 16),
             new DSAValidationParameters(Hex.decode("77d0f8c4dad15eb8c4f2f8d6726cefd96d5bb399"), 263));

         DSAParameters def1024Params = new DSAParameters(
             new BigInteger("fd7f53811d75122952df4a9c2eece4e7f611b7523cef4400c31e3f80" +
                             "b6512669455d402251fb593d8d58fabfc5f5ba30f6cb9b556cd7813b" +
                             "801d346ff26660b76b9950a5a49f9fe8047b1022c24fbba9d7feb7c6" +
                             "1bf83b57e7c6a8a6150f04fb83f6d3c51ec3023554135a169132f675" +
                             "f3ae2b61d72aeff22203199dd14801c7", 16),
             new BigInteger("9760508f15230bccb292b982a2eb840bf0581cf5", 16),
             new BigInteger("f7e1a085d69b3ddecbbcab5c36b857b97994afbbfa3aea82f9574c0b" +
                             "3d0782675159578ebad4594fe67107108180b449167123e84c281613" +
                             "b7cf09328cc8a6e13c167a8b547c8d28e0a3ae1e2bb3a675916ea37f" +
                             "0bfa213562f1fb627a01243bcca4f1bea8519089a883dfe15ae59f06" +
                             "928b665e807b552564014c3bfecf492a", 16),
             new DSAValidationParameters(Hex.decode("8d5155894229d5e689ee01e6018a237e2cae64cd"), 92));

         DSAParameters def2048Params = new DSAParameters(
             new BigInteger("95475cf5d93e596c3fcd1d902add02f427f5f3c7210313bb45fb4d5b" +
                             "b2e5fe1cbd678cd4bbdd84c9836be1f31c0777725aeb6c2fc38b85f4" +
                             "8076fa76bcd8146cc89a6fb2f706dd719898c2083dc8d896f84062e2" +
                             "c9c94d137b054a8d8096adb8d51952398eeca852a0af12df83e475aa" +
                             "65d4ec0c38a9560d5661186ff98b9fc9eb60eee8b030376b236bc73b" +
                             "e3acdbd74fd61c1d2475fa3077b8f080467881ff7e1ca56fee066d79" +
                             "506ade51edbb5443a563927dbc4ba520086746175c8885925ebc64c6" +
                             "147906773496990cb714ec667304e261faee33b3cbdf008e0c3fa906" +
                             "50d97d3909c9275bf4ac86ffcb3d03e6dfc8ada5934242dd6d3bcca2" +
                             "a406cb0b", 16),
             new BigInteger("f8183668ba5fc5bb06b5981e6d8b795d30b8978d43ca0ec572e37e09939a9773", 16),
             new BigInteger("42debb9da5b3d88cc956e08787ec3f3a09bba5f48b889a74aaf53174" +
                             "aa0fbe7e3c5b8fcd7a53bef563b0e98560328960a9517f4014d3325f" +
                             "c7962bf1e049370d76d1314a76137e792f3f0db859d095e4a5b93202" +
                             "4f079ecf2ef09c797452b0770e1350782ed57ddf794979dcef23cb96" +
                             "f183061965c4ebc93c9c71c56b925955a75f94cccf1449ac43d586d0" +
                             "beee43251b0b2287349d68de0d144403f13e802f4146d882e057af19" +
                             "b6f6275c6676c8fa0e3ca2713a3257fd1b27d0639f695e347d8d1cf9" +
                             "ac819a26ca9b04cb0eb9b7b035988d15bbac65212a55239cfc7e58fa" +
                             "e38d7250ab9991ffbc97134025fe8ce04c4399ad96569be91a546f49" +
                             "78693c7a", 16),
             new DSAValidationParameters(Hex.decode("b0b4417601b59cbc9d8ac8f935cadaec4f5fbb2f23785609ae466748d9b5a536"), 497));

         localSetGlobalProperty(Property.DSA_DEFAULT_PARAMS, def512Params, def768Params, def1024Params, def2048Params);
         localSetGlobalProperty(Property.DH_DEFAULT_PARAMS, toDH(def512Params), toDH(def768Params), toDH(def1024Params), toDH(def2048Params));
     }

     private CryptoServicesRegistrar()
     {

     }

     /**
      * Return the default source of randomness.
      *
      * @return the default SecureRandom
      * @throws IllegalStateException if no source of randomness has been provided.
      */
     public static SecureRandom getSecureRandom()
     {
         if (defaultSecureRandom == null)
         {
             return new SecureRandom();
         }

         return defaultSecureRandom;
     }

     /**
      * Set a default secure random to be used where none is otherwise provided.
      *
      * @param secureRandom the SecureRandom to use as the default.
      */
     public static void setSecureRandom(SecureRandom secureRandom)
     {
         checkPermission(CanSetDefaultRandom);

         defaultSecureRandom = secureRandom;
     }

     /**
      * Return the default value for a particular property if one exists. The look up is done on the thread's local
      * configuration first and then on the global configuration in no local configuration exists.
      *
      * @param property the property to look up.
      * @param <T> the type to be returned
      * @return null if the property is not set, the default value otherwise,
      */
     public static <T> T getProperty(Property property)
     {
         Object[] values = lookupProperty(property);

         if (values != null)
         {
             return (T)values[0];
         }

         return null;
     }

     private static Object[] lookupProperty(Property property)
     {
         Map<String, Object[]> properties = threadProperties.get();
         Object[] values;

         if (properties == null || !properties.containsKey(property.name))
         {
             values = globalProperties.get(property.name);
         }
         else
         {
             values = properties.get(property.name);
         }
         return values;
     }

     /**
      * Return an array representing the current values for a sized property such as DH_DEFAULT_PARAMS or
      * DSA_DEFAULT_PARAMS.
      *
      * @param property the name of the property to look up.
      * @param <T> the base type of the array to be returned.
      * @return null if the property is not set, an array of the current values otherwise.
      */
     public static <T> T[] getSizedProperty(Property property)
     {
         Object[] values = lookupProperty(property);

         if (values == null)
         {
             return null;
         }

         return (T[])values.clone();
     }

     /**
      * Return the value for a specific size for a sized property such as DH_DEFAULT_PARAMS or
      * DSA_DEFAULT_PARAMS.
      *
      * @param property the name of the property to look up.
      * @param size the size (in bits) of the defining value in the property type.
      * @param <T> the type of the value to be returned.
      * @return the current value for the size, null if there is no value set,
      */
     public static <T> T getSizedProperty(Property property, int size)
     {
         Object[] values = lookupProperty(property);

         if (values == null)
         {
             return null;
         }

         if (property.type.isAssignableFrom(DHParameters.class))
         {
             for (int i = 0; i != values.length; i++)
             {
                 DHParameters params = (DHParameters)values[i];

                 if (params.getP().bitLength() == size)
                 {
                     return (T)params;
                 }
             }
         }
         else if (property.type.isAssignableFrom(DSAParameters.class))
         {
             for (int i = 0; i != values.length; i++)
             {
                 DSAParameters params = (DSAParameters)values[i];

                 if (params.getP().bitLength() == size)
                 {
                     return (T)params;
                 }
             }
         }

         return null;
     }

     /**
      * Set the value of the the passed in property on the current thread only. More than
      * one value can be passed in for a sized property. If more than one value is provided the
      * first value in the argument list becomes the default value.
      *
      * @param property the name of the property to set.
      * @param propertyValue the values to assign to the property.
      * @param <T> the base type of the property value.
      */
     public static <T> void setThreadProperty(Property property, T... propertyValue)
     {
         checkPermission(CanSetThreadProperty);

         if (!property.type.isAssignableFrom(propertyValue[0].getClass()))
         {
             throw new IllegalArgumentException("Bad property value passed");
         }

         localSetThread(property, propertyValue.clone());
     }

     /**
      * Set the value of the the passed in property globally in the JVM. More than
      * one value can be passed in for a sized property. If more than one value is provided the
      * first value in the argument list becomes the default value.
      *
      * @param property the name of the property to set.
      * @param propertyValue the values to assign to the property.
      * @param <T> the base type of the property value.
      */
     public static <T> void setGlobalProperty(Property property, T... propertyValue)
     {
         checkPermission(CanSetDefaultProperty);

         localSetGlobalProperty(property, propertyValue.clone());
     }

     private static <T> void localSetThread(Property property, T[] propertyValue)
     {
         Map<String, Object[]> properties = threadProperties.get();

         if (properties == null)
         {
             properties = new HashMap<String, Object[]>();
             threadProperties.set(properties);
         }

         properties.put(property.name, propertyValue);
     }

     private static <T> void localSetGlobalProperty(Property property, T... propertyValue)
     {
         if (!property.type.isAssignableFrom(propertyValue[0].getClass()))
         {
             throw new IllegalArgumentException("Bad property value passed");
         }

         // set the property for the current thread as well to avoid mass confusion
         localSetThread(property, propertyValue);

         globalProperties.put(property.name, propertyValue);
     }

     /**
      * Clear the global value for the passed in property.
      *
      * @param property the property to be cleared.
      * @param <T> the base type of the property value
      * @return an array of T if a value was previously set, null otherwise.
      */
     public static <T> T[] clearGlobalProperty(Property property)
     {
         checkPermission(CanSetDefaultProperty);

         // clear the property for the current thread as well to avoid confusion
         localClearThreadProperty(property);

         return (T[])globalProperties.remove(property.name);
     }

     /**
      * Clear the thread local value for the passed in property.
      *
      * @param property the property to be cleared.
      * @param <T> the base type of the property value
      * @return an array of T if a value was previously set, null otherwise.
      */
     public static <T> T[] clearThreadProperty(Property property)
     {
         checkPermission(CanSetThreadProperty);

         return (T[])localClearThreadProperty(property);
     }

     private static Object[] localClearThreadProperty(Property property)
     {
         Map<String, Object[]> properties = threadProperties.get();

         if (properties == null)
         {
             properties = new HashMap<String, Object[]>();
             threadProperties.set(properties);
         }

         return properties.remove(property.name);
     }

     private static void checkPermission(final Permission permission)
     {
         final SecurityManager securityManager = System.getSecurityManager();

         if (securityManager != null)
         {
             AccessController.doPrivileged(new PrivilegedAction<Object>()
             {
                 public Object run()
                 {
                     securityManager.checkPermission(permission);

                     return null;
                 }
             });
         }
     }

     private static DHParameters toDH(DSAParameters dsaParams)
     {
         int pSize = dsaParams.getP().bitLength();
         int m = chooseLowerBound(pSize);
         return new DHParameters(dsaParams.getP(), dsaParams.getG(), dsaParams.getQ(), m, 0, null,
             new DHValidationParameters(dsaParams.getValidationParameters().getSeed(), dsaParams.getValidationParameters().getCounter()));
     }

     // based on lower limit of at least 2^{2 * bits_of_security}
     private static int chooseLowerBound(int pSize)
     {
         int m = 160;
         if (pSize > 1024)
         {
             if (pSize <= 2048)
             {
                 m = 224;
             }
             else if (pSize <= 3072)
             {
                 m = 256;
             }
             else if (pSize <= 7680)
             {
                 m = 384;
             }
             else
             {
                 m = 512;
             }
         }
         return m;
     }

     /**
      * Available properties that can be set.
      */
     public static final class Property
     {
         /**
          * The parameters to be used for processing implicitlyCA X9.62 parameters
          */
         public static final Property EC_IMPLICITLY_CA = new Property("ecImplicitlyCA", X9ECParameters.class);
         /**
          * The default parameters for a particular size of Diffie-Hellman key.This is a sized property.
          */
         public static final Property DH_DEFAULT_PARAMS= new Property("dhDefaultParams", DHParameters.class);
         /**
          * The default parameters for a particular size of DSA key. This is a sized property.
          */
         public static final Property DSA_DEFAULT_PARAMS= new Property("dsaDefaultParams", DSAParameters.class);
         private final String name;
         private final Class type;

         private Property(String name, Class type)
         {
             this.name = name;
             this.type = type;
         }
     }
 }
	package org.bouncycastle.crypto;

	import java.math.BigInteger;
	import java.security.AccessController;
	import java.security.Permission;
	import java.security.PrivilegedAction;
	import java.security.SecureRandom;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.Map;

	import org.bouncycastle.asn1.x9.X9ECParameters;
	import org.bouncycastle.crypto.params.DHParameters;
	import org.bouncycastle.crypto.params.DHValidationParameters;
	import org.bouncycastle.crypto.params.DSAParameters;
	import org.bouncycastle.crypto.params.DSAValidationParameters;
	import org.bouncycastle.util.encoders.Hex;

	/**
	* Basic registrar class for providing defaults for cryptography services in this module.
	*/
	public final class CryptoServicesRegistrar
	{
	private static final Permission CanSetDefaultProperty = new CryptoServicesPermission(CryptoServicesPermission.GLOBAL_CONFIG);
	private static final Permission CanSetThreadProperty = new CryptoServicesPermission(CryptoServicesPermission.THREAD_LOCAL_CONFIG);
	private static final Permission CanSetDefaultRandom = new CryptoServicesPermission(CryptoServicesPermission.DEFAULT_RANDOM);

	private static final ThreadLocal<Map<String, Object[]>> threadProperties = new ThreadLocal<Map<String, Object[]>>();
	private static final Map<String, Object[]> globalProperties = Collections.synchronizedMap(new HashMap<String, Object[]>());

	private static volatile SecureRandom defaultSecureRandom;

	static
	{
	// default domain parameters for DSA and Diffie-Hellman

	DSAParameters def512Params = new DSAParameters(
	new BigInteger("fca682ce8e12caba26efccf7110e526db078b05edecbcd1eb4a208f3ae1617ae01f35b91a47e6df63413c5e12ed0899bcd132acd50d99151bdc43ee737592e17", 16),
	new BigInteger("962eddcc369cba8ebb260ee6b6a126d9346e38c5", 16),
	new BigInteger("678471b27a9cf44ee91a49c5147db1a9aaf244f05a434d6486931d2d14271b9e35030b71fd73da179069b32e2935630e1c2062354d0da20a6c416e50be794ca4", 16),
	new DSAValidationParameters(Hex.decode("b869c82b35d70e1b1ff91b28e37a62ecdc34409b"), 123));

	DSAParameters def768Params = new DSAParameters(
	new BigInteger("e9e642599d355f37c97ffd3567120b8e25c9cd43e927b3a9670fbec5" +
	"d890141922d2c3b3ad2480093799869d1e846aab49fab0ad26d2ce6a" +
	"22219d470bce7d777d4a21fbe9c270b57f607002f3cef8393694cf45" +
	"ee3688c11a8c56ab127a3daf", 16),
	new BigInteger("9cdbd84c9f1ac2f38d0f80f42ab952e7338bf511", 16),
	new BigInteger("30470ad5a005fb14ce2d9dcd87e38bc7d1b1c5facbaecbe95f190aa7" +
	"a31d23c4dbbcbe06174544401a5b2c020965d8c2bd2171d366844577" +
	"1f74ba084d2029d83c1c158547f3a9f1a2715be23d51ae4d3e5a1f6a" +
	"7064f316933a346d3f529252", 16),
	new DSAValidationParameters(Hex.decode("77d0f8c4dad15eb8c4f2f8d6726cefd96d5bb399"), 263));

	DSAParameters def1024Params = new DSAParameters(
	new BigInteger("fd7f53811d75122952df4a9c2eece4e7f611b7523cef4400c31e3f80" +
	"b6512669455d402251fb593d8d58fabfc5f5ba30f6cb9b556cd7813b" +
	"801d346ff26660b76b9950a5a49f9fe8047b1022c24fbba9d7feb7c6" +
	"1bf83b57e7c6a8a6150f04fb83f6d3c51ec3023554135a169132f675" +
	"f3ae2b61d72aeff22203199dd14801c7", 16),
	new BigInteger("9760508f15230bccb292b982a2eb840bf0581cf5", 16),
	new BigInteger("f7e1a085d69b3ddecbbcab5c36b857b97994afbbfa3aea82f9574c0b" +
	"3d0782675159578ebad4594fe67107108180b449167123e84c281613" +
	"b7cf09328cc8a6e13c167a8b547c8d28e0a3ae1e2bb3a675916ea37f" +
	"0bfa213562f1fb627a01243bcca4f1bea8519089a883dfe15ae59f06" +
	"928b665e807b552564014c3bfecf492a", 16),
	new DSAValidationParameters(Hex.decode("8d5155894229d5e689ee01e6018a237e2cae64cd"), 92));

	DSAParameters def2048Params = new DSAParameters(
	new BigInteger("95475cf5d93e596c3fcd1d902add02f427f5f3c7210313bb45fb4d5b" +
	"b2e5fe1cbd678cd4bbdd84c9836be1f31c0777725aeb6c2fc38b85f4" +
	"8076fa76bcd8146cc89a6fb2f706dd719898c2083dc8d896f84062e2" +
	"c9c94d137b054a8d8096adb8d51952398eeca852a0af12df83e475aa" +
	"65d4ec0c38a9560d5661186ff98b9fc9eb60eee8b030376b236bc73b" +
	"e3acdbd74fd61c1d2475fa3077b8f080467881ff7e1ca56fee066d79" +
	"506ade51edbb5443a563927dbc4ba520086746175c8885925ebc64c6" +
	"147906773496990cb714ec667304e261faee33b3cbdf008e0c3fa906" +
	"50d97d3909c9275bf4ac86ffcb3d03e6dfc8ada5934242dd6d3bcca2" +
	"a406cb0b", 16),
	new BigInteger("f8183668ba5fc5bb06b5981e6d8b795d30b8978d43ca0ec572e37e09939a9773", 16),
	new BigInteger("42debb9da5b3d88cc956e08787ec3f3a09bba5f48b889a74aaf53174" +
	"aa0fbe7e3c5b8fcd7a53bef563b0e98560328960a9517f4014d3325f" +
	"c7962bf1e049370d76d1314a76137e792f3f0db859d095e4a5b93202" +
	"4f079ecf2ef09c797452b0770e1350782ed57ddf794979dcef23cb96" +
	"f183061965c4ebc93c9c71c56b925955a75f94cccf1449ac43d586d0" +
	"beee43251b0b2287349d68de0d144403f13e802f4146d882e057af19" +
	"b6f6275c6676c8fa0e3ca2713a3257fd1b27d0639f695e347d8d1cf9" +
	"ac819a26ca9b04cb0eb9b7b035988d15bbac65212a55239cfc7e58fa" +
	"e38d7250ab9991ffbc97134025fe8ce04c4399ad96569be91a546f49" +
	"78693c7a", 16),
	new DSAValidationParameters(Hex.decode("b0b4417601b59cbc9d8ac8f935cadaec4f5fbb2f23785609ae466748d9b5a536"), 497));

	localSetGlobalProperty(Property.DSA_DEFAULT_PARAMS, def512Params, def768Params, def1024Params, def2048Params);
	localSetGlobalProperty(Property.DH_DEFAULT_PARAMS, toDH(def512Params), toDH(def768Params), toDH(def1024Params), toDH(def2048Params));
	}

	private CryptoServicesRegistrar()
	{

	}

	/**
	* Return the default source of randomness.
	*
	* @return the default SecureRandom
	* @throws IllegalStateException if no source of randomness has been provided.
	*/
	public static SecureRandom getSecureRandom()
	{
	if (defaultSecureRandom == null)
	{
	return new SecureRandom();
	}

	return defaultSecureRandom;
	}

	/**
	* Set a default secure random to be used where none is otherwise provided.
	*
	* @param secureRandom the SecureRandom to use as the default.
	*/
	public static void setSecureRandom(SecureRandom secureRandom)
	{
	checkPermission(CanSetDefaultRandom);

	defaultSecureRandom = secureRandom;
	}

	/**
	* Return the default value for a particular property if one exists. The look up is done on the thread's local
	* configuration first and then on the global configuration in no local configuration exists.
	*
	* @param property the property to look up.
	* @param <T> the type to be returned
	* @return null if the property is not set, the default value otherwise,
	*/
	public static <T> T getProperty(Property property)
	{
	Object[] values = lookupProperty(property);

	if (values != null)
	{
	return (T)values[0];
	}

	return null;
	}

	private static Object[] lookupProperty(Property property)
	{
	Map<String, Object[]> properties = threadProperties.get();
	Object[] values;

	if (properties == null \|\| !properties.containsKey(property.name))
	{
	values = globalProperties.get(property.name);
	}
	else
	{
	values = properties.get(property.name);
	}
	return values;
	}

	/**
	* Return an array representing the current values for a sized property such as DH_DEFAULT_PARAMS or
	* DSA_DEFAULT_PARAMS.
	*
	* @param property the name of the property to look up.
	* @param <T> the base type of the array to be returned.
	* @return null if the property is not set, an array of the current values otherwise.
	*/
	public static <T> T[] getSizedProperty(Property property)
	{
	Object[] values = lookupProperty(property);

	if (values == null)
	{
	return null;
	}

	return (T[])values.clone();
	}

	/**
	* Return the value for a specific size for a sized property such as DH_DEFAULT_PARAMS or
	* DSA_DEFAULT_PARAMS.
	*
	* @param property the name of the property to look up.
	* @param size the size (in bits) of the defining value in the property type.
	* @param <T> the type of the value to be returned.
	* @return the current value for the size, null if there is no value set,
	*/
	public static <T> T getSizedProperty(Property property, int size)
	{
	Object[] values = lookupProperty(property);

	if (values == null)
	{
	return null;
	}

	if (property.type.isAssignableFrom(DHParameters.class))
	{
	for (int i = 0; i != values.length; i++)
	{
	DHParameters params = (DHParameters)values[i];

	if (params.getP().bitLength() == size)
	{
	return (T)params;
	}
	}
	}
	else if (property.type.isAssignableFrom(DSAParameters.class))
	{
	for (int i = 0; i != values.length; i++)
	{
	DSAParameters params = (DSAParameters)values[i];

	if (params.getP().bitLength() == size)
	{
	return (T)params;
	}
	}
	}

	return null;
	}

	/**
	* Set the value of the the passed in property on the current thread only. More than
	* one value can be passed in for a sized property. If more than one value is provided the
	* first value in the argument list becomes the default value.
	*
	* @param property the name of the property to set.
	* @param propertyValue the values to assign to the property.
	* @param <T> the base type of the property value.
	*/
	public static <T> void setThreadProperty(Property property, T... propertyValue)
	{
	checkPermission(CanSetThreadProperty);

	if (!property.type.isAssignableFrom(propertyValue[0].getClass()))
	{
	throw new IllegalArgumentException("Bad property value passed");
	}

	localSetThread(property, propertyValue.clone());
	}

	/**
	* Set the value of the the passed in property globally in the JVM. More than
	* one value can be passed in for a sized property. If more than one value is provided the
	* first value in the argument list becomes the default value.
	*
	* @param property the name of the property to set.
	* @param propertyValue the values to assign to the property.
	* @param <T> the base type of the property value.
	*/
	public static <T> void setGlobalProperty(Property property, T... propertyValue)
	{
	checkPermission(CanSetDefaultProperty);

	localSetGlobalProperty(property, propertyValue.clone());
	}

	private static <T> void localSetThread(Property property, T[] propertyValue)
	{
	Map<String, Object[]> properties = threadProperties.get();

	if (properties == null)
	{
	properties = new HashMap<String, Object[]>();
	threadProperties.set(properties);
	}

	properties.put(property.name, propertyValue);
	}

	private static <T> void localSetGlobalProperty(Property property, T... propertyValue)
	{
	if (!property.type.isAssignableFrom(propertyValue[0].getClass()))
	{
	throw new IllegalArgumentException("Bad property value passed");
	}

	// set the property for the current thread as well to avoid mass confusion
	localSetThread(property, propertyValue);

	globalProperties.put(property.name, propertyValue);
	}

	/**
	* Clear the global value for the passed in property.
	*
	* @param property the property to be cleared.
	* @param <T> the base type of the property value
	* @return an array of T if a value was previously set, null otherwise.
	*/
	public static <T> T[] clearGlobalProperty(Property property)
	{
	checkPermission(CanSetDefaultProperty);

	// clear the property for the current thread as well to avoid confusion
	localClearThreadProperty(property);

	return (T[])globalProperties.remove(property.name);
	}

	/**
	* Clear the thread local value for the passed in property.
	*
	* @param property the property to be cleared.
	* @param <T> the base type of the property value
	* @return an array of T if a value was previously set, null otherwise.
	*/
	public static <T> T[] clearThreadProperty(Property property)
	{
	checkPermission(CanSetThreadProperty);

	return (T[])localClearThreadProperty(property);
	}

	private static Object[] localClearThreadProperty(Property property)
	{
	Map<String, Object[]> properties = threadProperties.get();

	if (properties == null)
	{
	properties = new HashMap<String, Object[]>();
	threadProperties.set(properties);
	}

	return properties.remove(property.name);
	}

	private static void checkPermission(final Permission permission)
	{
	final SecurityManager securityManager = System.getSecurityManager();

	if (securityManager != null)
	{
	AccessController.doPrivileged(new PrivilegedAction<Object>()
	{
	public Object run()
	{
	securityManager.checkPermission(permission);

	return null;
	}
	});
	}
	}

	private static DHParameters toDH(DSAParameters dsaParams)
	{
	int pSize = dsaParams.getP().bitLength();
	int m = chooseLowerBound(pSize);
	return new DHParameters(dsaParams.getP(), dsaParams.getG(), dsaParams.getQ(), m, 0, null,
	new DHValidationParameters(dsaParams.getValidationParameters().getSeed(), dsaParams.getValidationParameters().getCounter()));
	}

	// based on lower limit of at least 2^{2 * bits_of_security}
	private static int chooseLowerBound(int pSize)
	{
	int m = 160;
	if (pSize > 1024)
	{
	if (pSize <= 2048)
	{
	m = 224;
	}
	else if (pSize <= 3072)
	{
	m = 256;
	}
	else if (pSize <= 7680)
	{
	m = 384;
	}
	else
	{
	m = 512;
	}
	}
	return m;
	}

	/**
	* Available properties that can be set.
	*/
	public static final class Property
	{
	/**
	* The parameters to be used for processing implicitlyCA X9.62 parameters
	*/
	public static final Property EC_IMPLICITLY_CA = new Property("ecImplicitlyCA", X9ECParameters.class);
	/**
	* The default parameters for a particular size of Diffie-Hellman key.This is a sized property.
	*/
	public static final Property DH_DEFAULT_PARAMS= new Property("dhDefaultParams", DHParameters.class);
	/**
	* The default parameters for a particular size of DSA key. This is a sized property.
	*/
	public static final Property DSA_DEFAULT_PARAMS= new Property("dsaDefaultParams", DSAParameters.class);
	private final String name;
	private final Class type;

	private Property(String name, Class type)
	{
	this.name = name;
	this.type = type;
	}
	}
	}