--- a/jdk/src/java.base/share/classes/java/security/SecureRandom.java Thu May 05 16:36:06 2016 -0700
+++ b/jdk/src/java.base/share/classes/java/security/SecureRandom.java Fri May 06 11:38:44 2016 +0800
@@ -38,52 +38,87 @@
* This class provides a cryptographically strong random number
* generator (RNG).
*
- * <p>A cryptographically strong random number
- * minimally complies with the statistical random number generator tests
- * specified in
+ * <p>A cryptographically strong random number minimally complies with the
+ * statistical random number generator tests specified in
* <a href="http://csrc.nist.gov/publications/fips/fips140-2/fips1402.pdf">
* <i>FIPS 140-2, Security Requirements for Cryptographic Modules</i></a>,
* section 4.9.1.
- * Additionally, SecureRandom must produce non-deterministic output.
- * Therefore any seed material passed to a SecureRandom object must be
- * unpredictable, and all SecureRandom output sequences must be
+ * Additionally, {@code SecureRandom} must produce non-deterministic output.
+ * Therefore any seed material passed to a {@code SecureRandom} object must be
+ * unpredictable, and all {@code SecureRandom} output sequences must be
* cryptographically strong, as described in
* <a href="http://tools.ietf.org/html/rfc4086">
* <i>RFC 4086: Randomness Requirements for Security</i></a>.
*
- * <p>A caller obtains a SecureRandom instance via the
- * no-argument constructor or one of the {@code getInstance} methods:
- *
- * <pre>
- * SecureRandom random = new SecureRandom();
- * </pre>
- *
- * <p> Many SecureRandom implementations are in the form of a pseudo-random
- * number generator (PRNG), which means they use a deterministic algorithm
- * to produce a pseudo-random sequence from a true random seed.
+ * <p> Many {@code SecureRandom} implementations are in the form of a
+ * pseudo-random number generator (PRNG, also known as deterministic random
+ * bits generator or DRBG), which means they use a deterministic algorithm
+ * to produce a pseudo-random sequence from a random seed.
* Other implementations may produce true random numbers,
* and yet others may use a combination of both techniques.
*
- * <p> Typical callers of SecureRandom invoke the following methods
+ * <p>A caller obtains a {@code SecureRandom} instance via the
+ * no-argument constructor or one of the {@code getInstance} methods.
+ * For example:
+ *
+ * <blockquote><pre>
+ * SecureRandom r1 = new SecureRandom();
+ * SecureRandom r2 = SecureRandom.getInstance("NativePRNG");
+ * SecureRandom r3 = SecureRandom("DRBG",
+ * DrbgParameters.Instantiation(128, RESEED_ONLY, null));</pre>
+ * </blockquote>
+ *
+ * <p> The third statement above returns a {@code SecureRandom} object of the
+ * specific algorithm supporting the specific instantiate parameters. The
+ * implementation's effective instantiated parameters must match this minimum
+ * request but is not necessarily the same. For example, even if the request
+ * does not require a certain feature, the actual instantiation can provide
+ * the feature. An implementation may lazily instantiate a {@code SecureRandom}
+ * until it's actually used, but the effective instantiate parameters must be
+ * determined right after it's created and {@link #getParameters()} should
+ * always return the same result unchanged.
+ *
+ * <p> Typical callers of {@code SecureRandom} invoke the following methods
* to retrieve random bytes:
*
- * <pre>
- * SecureRandom random = new SecureRandom();
- * byte[] bytes = new byte[20];
- * random.nextBytes(bytes);
- * </pre>
+ * <blockquote><pre>
+ * SecureRandom random = new SecureRandom();
+ * byte[] bytes = new byte[20];
+ * random.nextBytes(bytes);</pre>
+ * </blockquote>
*
- * <p> Callers may also invoke the {@code generateSeed} method
+ * <p> Callers may also invoke the {@link #generateSeed} method
* to generate a given number of seed bytes (to seed other random number
* generators, for example):
- * <pre>
- * byte[] seed = random.generateSeed(20);
- * </pre>
+ *
+ * <blockquote><pre>
+ * byte[] seed = random.generateSeed(20);</pre>
+ * </blockquote>
+ *
+ * <p> A newly created PRNG {@code SecureRandom} object is not seeded (except
+ * if it is created by {@link #SecureRandom(byte[])}). The first call to
+ * {@code nextBytes} will force it to seed itself from an implementation-
+ * specific entropy source. This self-seeding will not occur if {@code setSeed}
+ * was previously called.
*
- * Note: Depending on the implementation, the {@code generateSeed} and
- * {@code nextBytes} methods may block as entropy is being gathered,
- * for example, if they need to read from /dev/random on various Unix-like
- * operating systems.
+ * <p> A {@code SecureRandom} can be reseeded at any time by calling the
+ * {@code reseed} or {@code setSeed} method. The {@code reseed} method
+ * reads entropy input from its entropy source to reseed itself.
+ * The {@code setSeed} method requires the caller to provide the seed.
+ *
+ * <p> Please note that {@code reseed} may not be supported by all
+ * {@code SecureRandom} implementations.
+ *
+ * <p> Some {@code SecureRandom} implementations may accept a
+ * {@link SecureRandomParameters} parameter in its
+ * {@link #nextBytes(byte[], SecureRandomParameters)} and
+ * {@link #reseed(SecureRandomParameters)} methods to further
+ * control the behavior of the methods.
+ *
+ * <p> Note: Depending on the implementation, the {@code generateSeed},
+ * {@code reseed} and {@code nextBytes} methods may block as entropy is being
+ * gathered, for example, if the entropy source is /dev/random on various
+ * Unix-like operating systems.
*
* @see java.security.SecureRandomSpi
* @see java.util.Random
@@ -132,26 +167,19 @@
*
* <p> This constructor traverses the list of registered security Providers,
* starting with the most preferred Provider.
- * A new SecureRandom object encapsulating the
- * SecureRandomSpi implementation from the first
- * Provider that supports a SecureRandom (RNG) algorithm is returned.
+ * A new {@code SecureRandom} object encapsulating the
+ * {@code SecureRandomSpi} implementation from the first
+ * Provider that supports a {@code SecureRandom} (RNG) algorithm is returned.
* If none of the Providers support a RNG algorithm,
* then an implementation-specific default is returned.
*
* <p> Note that the list of registered providers may be retrieved via
* the {@link Security#getProviders() Security.getProviders()} method.
*
- * <p> See the SecureRandom section in the <a href=
+ * <p> See the {@code SecureRandom} section in the <a href=
* "{@docRoot}/../technotes/guides/security/StandardNames.html#SecureRandom">
* Java Cryptography Architecture Standard Algorithm Name Documentation</a>
* for information about standard RNG algorithm names.
- *
- * <p> The returned SecureRandom object has not been seeded. To seed the
- * returned object, call the {@code setSeed} method.
- * If {@code setSeed} is not called, the first call to
- * {@code nextBytes} will force the SecureRandom object to seed itself.
- * This self-seeding will not occur if {@code setSeed} was
- * previously called.
*/
public SecureRandom() {
/*
@@ -166,20 +194,20 @@
/**
* Constructs a secure random number generator (RNG) implementing the
* default random number algorithm.
- * The SecureRandom instance is seeded with the specified seed bytes.
+ * The {@code SecureRandom} instance is seeded with the specified seed bytes.
*
* <p> This constructor traverses the list of registered security Providers,
* starting with the most preferred Provider.
- * A new SecureRandom object encapsulating the
- * SecureRandomSpi implementation from the first
- * Provider that supports a SecureRandom (RNG) algorithm is returned.
+ * A new {@code SecureRandom} object encapsulating the
+ * {@code SecureRandomSpi} implementation from the first
+ * Provider that supports a {@code SecureRandom} (RNG) algorithm is returned.
* If none of the Providers support a RNG algorithm,
* then an implementation-specific default is returned.
*
* <p> Note that the list of registered providers may be retrieved via
* the {@link Security#getProviders() Security.getProviders()} method.
*
- * <p> See the SecureRandom section in the <a href=
+ * <p> See the {@code SecureRandom} section in the <a href=
* "{@docRoot}/../technotes/guides/security/StandardNames.html#SecureRandom">
* Java Cryptography Architecture Standard Algorithm Name Documentation</a>
* for information about standard RNG algorithm names.
@@ -225,9 +253,9 @@
}
/**
- * Creates a SecureRandom object.
+ * Creates a {@code SecureRandom} object.
*
- * @param secureRandomSpi the SecureRandom implementation.
+ * @param secureRandomSpi the {@code SecureRandom} implementation.
* @param provider the provider.
*/
protected SecureRandom(SecureRandomSpi secureRandomSpi,
@@ -249,25 +277,18 @@
}
/**
- * Returns a SecureRandom object that implements the specified
+ * Returns a {@code SecureRandom} object that implements the specified
* Random Number Generator (RNG) algorithm.
*
* <p> This method traverses the list of registered security Providers,
* starting with the most preferred Provider.
- * A new SecureRandom object encapsulating the
- * SecureRandomSpi implementation from the first
+ * A new {@code SecureRandom} object encapsulating the
+ * {@code SecureRandomSpi} implementation from the first
* Provider that supports the specified algorithm is returned.
*
* <p> Note that the list of registered providers may be retrieved via
* the {@link Security#getProviders() Security.getProviders()} method.
*
- * <p> The returned SecureRandom object has not been seeded. To seed the
- * returned object, call the {@code setSeed} method.
- * If {@code setSeed} is not called, the first call to
- * {@code nextBytes} will force the SecureRandom object to seed itself.
- * This self-seeding will not occur if {@code setSeed} was
- * previously called.
- *
* @implNote
* The JDK Reference Implementation additionally uses the
* {@code jdk.security.provider.preferred}
@@ -277,15 +298,15 @@
* {@link Security#getProviders() Security.getProviders()}.
*
* @param algorithm the name of the RNG algorithm.
- * See the SecureRandom section in the <a href=
+ * See the {@code SecureRandom} section in the <a href=
* "{@docRoot}/../technotes/guides/security/StandardNames.html#SecureRandom">
* Java Cryptography Architecture Standard Algorithm Name Documentation</a>
* for information about standard RNG algorithm names.
*
- * @return the new SecureRandom object.
+ * @return the new {@code SecureRandom} object.
*
* @exception NoSuchAlgorithmException if no Provider supports a
- * SecureRandomSpi implementation for the
+ * {@code SecureRandomSpi} implementation for the
* specified algorithm.
*
* @see Provider
@@ -295,49 +316,42 @@
public static SecureRandom getInstance(String algorithm)
throws NoSuchAlgorithmException {
Instance instance = GetInstance.getInstance("SecureRandom",
- SecureRandomSpi.class, algorithm);
+ SecureRandomSpi.class, algorithm);
return new SecureRandom((SecureRandomSpi)instance.impl,
- instance.provider, algorithm);
+ instance.provider, algorithm);
}
/**
- * Returns a SecureRandom object that implements the specified
+ * Returns a {@code SecureRandom} object that implements the specified
* Random Number Generator (RNG) algorithm.
*
- * <p> A new SecureRandom object encapsulating the
- * SecureRandomSpi implementation from the specified provider
+ * <p> A new {@code SecureRandom} object encapsulating the
+ * {@code SecureRandomSpi} implementation from the specified provider
* is returned. The specified provider must be registered
* in the security provider list.
*
* <p> Note that the list of registered providers may be retrieved via
* the {@link Security#getProviders() Security.getProviders()} method.
*
- * <p> The returned SecureRandom object has not been seeded. To seed the
- * returned object, call the {@code setSeed} method.
- * If {@code setSeed} is not called, the first call to
- * {@code nextBytes} will force the SecureRandom object to seed itself.
- * This self-seeding will not occur if {@code setSeed} was
- * previously called.
- *
* @param algorithm the name of the RNG algorithm.
- * See the SecureRandom section in the <a href=
+ * See the {@code SecureRandom} section in the <a href=
* "{@docRoot}/../technotes/guides/security/StandardNames.html#SecureRandom">
* Java Cryptography Architecture Standard Algorithm Name Documentation</a>
* for information about standard RNG algorithm names.
*
* @param provider the name of the provider.
*
- * @return the new SecureRandom object.
+ * @return the new {@code SecureRandom} object.
*
- * @exception NoSuchAlgorithmException if a SecureRandomSpi
- * implementation for the specified algorithm is not
- * available from the specified provider.
+ * @throws NoSuchAlgorithmException if a {@code SecureRandomSpi}
+ * implementation for the specified algorithm is not
+ * available from the specified provider.
*
- * @exception NoSuchProviderException if the specified provider is not
- * registered in the security provider list.
+ * @throws NoSuchProviderException if the specified provider is not
+ * registered in the security provider list.
*
- * @exception IllegalArgumentException if the provider name is null
- * or empty.
+ * @throws IllegalArgumentException if the provider name is null
+ * or empty.
*
* @see Provider
*
@@ -352,36 +366,29 @@
}
/**
- * Returns a SecureRandom object that implements the specified
+ * Returns a {@code SecureRandom} object that implements the specified
* Random Number Generator (RNG) algorithm.
*
- * <p> A new SecureRandom object encapsulating the
- * SecureRandomSpi implementation from the specified Provider
- * object is returned. Note that the specified Provider object
+ * <p> A new {@code SecureRandom} object encapsulating the
+ * {@code SecureRandomSpi} implementation from the specified {@code Provider}
+ * object is returned. Note that the specified {@code Provider} object
* does not have to be registered in the provider list.
*
- * <p> The returned SecureRandom object has not been seeded. To seed the
- * returned object, call the {@code setSeed} method.
- * If {@code setSeed} is not called, the first call to
- * {@code nextBytes} will force the SecureRandom object to seed itself.
- * This self-seeding will not occur if {@code setSeed} was
- * previously called.
- *
* @param algorithm the name of the RNG algorithm.
- * See the SecureRandom section in the <a href=
+ * See the {@code SecureRandom} section in the <a href=
* "{@docRoot}/../technotes/guides/security/StandardNames.html#SecureRandom">
* Java Cryptography Architecture Standard Algorithm Name Documentation</a>
* for information about standard RNG algorithm names.
*
* @param provider the provider.
*
- * @return the new SecureRandom object.
+ * @return the new {@code SecureRandom} object.
*
- * @exception NoSuchAlgorithmException if a SecureRandomSpi
- * implementation for the specified algorithm is not available
- * from the specified Provider object.
+ * @throws NoSuchAlgorithmException if a {@code SecureRandomSpi}
+ * implementation for the specified algorithm is not available
+ * from the specified {@code Provider} object.
*
- * @exception IllegalArgumentException if the specified provider is null.
+ * @throws IllegalArgumentException if the specified provider is null.
*
* @see Provider
*
@@ -396,24 +403,178 @@
}
/**
- * Returns the SecureRandomSpi of this SecureRandom object.
+ * Returns a {@code SecureRandom} object that implements the specified
+ * Random Number Generator (RNG) algorithm and supports the specified
+ * {@code SecureRandomParameters} request.
+ *
+ * <p> This method traverses the list of registered security Providers,
+ * starting with the most preferred Provider.
+ * A new {@code SecureRandom} object encapsulating the
+ * {@code SecureRandomSpi} implementation from the first
+ * Provider that supports the specified algorithm and the specified
+ * {@code SecureRandomParameters} is returned.
+ *
+ * <p> Note that the list of registered providers may be retrieved via
+ * the {@link Security#getProviders() Security.getProviders()} method.
+ *
+ * @implNote
+ * The JDK Reference Implementation additionally uses the
+ * {@code jdk.security.provider.preferred} property to determine
+ * the preferred provider order for the specified algorithm. This
+ * may be different than the order of providers returned by
+ * {@link Security#getProviders() Security.getProviders()}.
+ *
+ * @param algorithm the name of the RNG algorithm.
+ * See the {@code SecureRandom} section in the <a href=
+ * "{@docRoot}/../technotes/guides/security/StandardNames.html#SecureRandom">
+ * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
+ * for information about standard RNG algorithm names.
+ *
+ * @param params the {@code SecureRandomParameters}
+ * the newly created {@code SecureRandom} object must support.
+ *
+ * @return the new {@code SecureRandom} object.
+ *
+ * @throws NoSuchAlgorithmException if no Provider supports a
+ * {@code SecureRandomSpi} implementation for the specified
+ * algorithm and parameters.
+ *
+ * @throws IllegalArgumentException if the specified params is null.
+ *
+ * @see Provider
+ *
+ * @since 9
+ */
+ public static SecureRandom getInstance(
+ String algorithm, SecureRandomParameters params)
+ throws NoSuchAlgorithmException {
+ if (params == null) {
+ throw new IllegalArgumentException("params cannot be null");
+ }
+ Instance instance = GetInstance.getInstance("SecureRandom",
+ SecureRandomSpi.class, algorithm, params);
+ return new SecureRandom((SecureRandomSpi)instance.impl,
+ instance.provider, algorithm);
+ }
+
+ /**
+ * Returns a {@code SecureRandom} object that implements the specified
+ * Random Number Generator (RNG) algorithm and supports the specified
+ * {@code SecureRandomParameters} request.
+ *
+ * <p> A new {@code SecureRandom} object encapsulating the
+ * {@code SecureRandomSpi} implementation from the specified provider
+ * is returned. The specified provider must be registered
+ * in the security provider list.
+ *
+ * <p> Note that the list of registered providers may be retrieved via
+ * the {@link Security#getProviders() Security.getProviders()} method.
+ *
+ * @param algorithm the name of the RNG algorithm.
+ * See the {@code SecureRandom} section in the <a href=
+ * "{@docRoot}/../technotes/guides/security/StandardNames.html#SecureRandom">
+ * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
+ * for information about standard RNG algorithm names.
+ *
+ * @param params the {@code SecureRandomParameters}
+ * the newly created {@code SecureRandom} object must support.
+ *
+ * @param provider the name of the provider.
+ *
+ * @return the new {@code SecureRandom} object.
+ *
+ * @throws NoSuchAlgorithmException if the specified provider does not
+ * support a {@code SecureRandomSpi} implementation for the
+ * specified algorithm and parameters.
+ *
+ * @throws NoSuchProviderException if the specified provider is not
+ * registered in the security provider list.
+ *
+ * @throws IllegalArgumentException if the provider name is null
+ * or empty, or params is null.
+ *
+ * @see Provider
+ *
+ * @since 9
+ */
+ public static SecureRandom getInstance(String algorithm,
+ SecureRandomParameters params, String provider)
+ throws NoSuchAlgorithmException, NoSuchProviderException {
+ if (params == null) {
+ throw new IllegalArgumentException("params cannot be null");
+ }
+ Instance instance = GetInstance.getInstance("SecureRandom",
+ SecureRandomSpi.class, algorithm, params, provider);
+ return new SecureRandom((SecureRandomSpi)instance.impl,
+ instance.provider, algorithm);
+ }
+
+ /**
+ * Returns a {@code SecureRandom} object that implements the specified
+ * Random Number Generator (RNG) algorithm and supports the specified
+ * {@code SecureRandomParameters} request.
+ *
+ * <p> A new {@code SecureRandom} object encapsulating the
+ * {@code SecureRandomSpi} implementation from the specified
+ * {@code Provider} object is returned. Note that the specified
+ * {@code Provider} object does not have to be registered in the
+ * provider list.
+ *
+ * @param algorithm the name of the RNG algorithm.
+ * See the {@code SecureRandom} section in the <a href=
+ * "{@docRoot}/../technotes/guides/security/StandardNames.html#SecureRandom">
+ * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
+ * for information about standard RNG algorithm names.
+ *
+ * @param params the {@code SecureRandomParameters}
+ * the newly created {@code SecureRandom} object must support.
+ *
+ * @param provider the provider.
+ *
+ * @return the new {@code SecureRandom} object.
+ *
+ * @throws NoSuchAlgorithmException if the specified provider does not
+ * support a {@code SecureRandomSpi} implementation for the
+ * specified algorithm and parameters.
+ *
+ * @throws IllegalArgumentException if the specified provider or params
+ * is null.
+ *
+ * @see Provider
+ *
+ * @since 9
+ */
+ public static SecureRandom getInstance(String algorithm,
+ SecureRandomParameters params, Provider provider)
+ throws NoSuchAlgorithmException {
+ if (params == null) {
+ throw new IllegalArgumentException("params cannot be null");
+ }
+ Instance instance = GetInstance.getInstance("SecureRandom",
+ SecureRandomSpi.class, algorithm, params, provider);
+ return new SecureRandom((SecureRandomSpi)instance.impl,
+ instance.provider, algorithm);
+ }
+
+ /**
+ * Returns the {@code SecureRandomSpi} of this {@code SecureRandom} object.
*/
SecureRandomSpi getSecureRandomSpi() {
return secureRandomSpi;
}
/**
- * Returns the provider of this SecureRandom object.
+ * Returns the provider of this {@code SecureRandom} object.
*
- * @return the provider of this SecureRandom object.
+ * @return the provider of this {@code SecureRandom} object.
*/
public final Provider getProvider() {
return provider;
}
/**
- * Returns the name of the algorithm implemented by this SecureRandom
- * object.
+ * Returns the name of the algorithm implemented by this
+ * {@code SecureRandom} object.
*
* @return the name of the algorithm or {@code unknown}
* if the algorithm name cannot be determined.
@@ -424,9 +585,49 @@
}
/**
- * Reseeds this random object. The given seed supplements, rather than
- * replaces, the existing seed. Thus, repeated calls are guaranteed
- * never to reduce randomness.
+ * Returns a Human-readable string representation of this
+ * {@code SecureRandom}.
+ *
+ * @return the string representation
+ *
+ * @since 9
+ */
+ @Override
+ public String toString() {
+ return secureRandomSpi.toString();
+ }
+
+ /**
+ * Returns the effective {@link SecureRandomParameters} for this
+ * {@code SecureRandom} instance.
+ * <p>
+ * The returned value can be different from the
+ * {@code SecureRandomParameters} object passed into a {@code getInstance}
+ * method, but it cannot change during the lifetime of this
+ * {@code SecureRandom} object.
+ * <p>
+ * A caller can use the returned value to find out what features this
+ * {@code SecureRandom} supports.
+ *
+ * @return the effective {@link SecureRandomParameters} parameters,
+ * or {@code null} if no parameters were used.
+ *
+ * @since 9
+ * @see SecureRandomSpi
+ */
+ public SecureRandomParameters getParameters() {
+ return secureRandomSpi.engineGetParameters();
+ }
+
+ /**
+ * Reseeds this random object with the given seed. The seed supplements,
+ * rather than replaces, the existing seed. Thus, repeated calls are
+ * guaranteed never to reduce randomness.
+ * <p>
+ * A PRNG {@code SecureRandom} will not seed itself automatically if
+ * {@code setSeed} is called before any {@code nextBytes} or {@code reseed}
+ * calls. The caller should make sure that the {@code seed} argument
+ * contains enough entropy for the security of this {@code SecureRandom}.
*
* @param seed the seed.
*
@@ -458,18 +659,13 @@
* yet been initialized at that point.
*/
if (seed != 0) {
- secureRandomSpi.engineSetSeed(longToByteArray(seed));
+ this.secureRandomSpi.engineSetSeed(longToByteArray(seed));
}
}
/**
* Generates a user-specified number of random bytes.
*
- * <p> If a call to {@code setSeed} had not occurred previously,
- * the first call to this method forces this SecureRandom object
- * to seed itself. This self-seeding will not occur if
- * {@code setSeed} was previously called.
- *
* @param bytes the array to be filled in with random bytes.
*/
@Override
@@ -478,6 +674,28 @@
}
/**
+ * Generates a user-specified number of random bytes with
+ * additional parameters.
+ *
+ * @param bytes the array to be filled in with random bytes
+ * @param params additional parameters
+ * @throws NullPointerException if {@code bytes} is null
+ * @throws UnsupportedOperationException if the underlying provider
+ * implementation has not overridden this method
+ * @throws IllegalArgumentException if {@code params} is {@code null},
+ * illegal or unsupported by this {@code SecureRandom}
+ *
+ * @since 9
+ */
+ public synchronized void nextBytes(
+ byte[] bytes, SecureRandomParameters params) {
+ if (params == null) {
+ throw new IllegalArgumentException("params cannot be null");
+ }
+ secureRandomSpi.engineNextBytes(Objects.requireNonNull(bytes), params);
+ }
+
+ /**
* Generates an integer containing the user-specified number of
* pseudo-random bits (right justified, with leading zeros). This
* method overrides a {@code java.util.Random} method, and serves
@@ -512,7 +730,7 @@
*
* <p>This method is only included for backwards compatibility.
* The caller is encouraged to use one of the alternative
- * {@code getInstance} methods to obtain a SecureRandom object, and
+ * {@code getInstance} methods to obtain a {@code SecureRandom} object, and
* then call the {@code generateSeed} method to obtain seed bytes
* from that object.
*
@@ -537,10 +755,13 @@
* call may be used to seed other random number generators.
*
* @param numBytes the number of seed bytes to generate.
- *
+ * @throws IllegalArgumentException if {@code numBytes} is negative
* @return the seed bytes.
*/
public byte[] generateSeed(int numBytes) {
+ if (numBytes < 0) {
+ throw new IllegalArgumentException("numBytes cannot be negative");
+ }
return secureRandomSpi.engineGenerateSeed(numBytes);
}
@@ -562,8 +783,8 @@
/**
* Gets a default PRNG algorithm by looking through all registered
* providers. Returns the first PRNG algorithm of the first provider that
- * has registered a SecureRandom implementation, or null if none of the
- * registered providers supplies a SecureRandom implementation.
+ * has registered a {@code SecureRandom} implementation, or null if none of
+ * the registered providers supplies a {@code SecureRandom} implementation.
*/
private static String getPrngAlgorithm() {
for (Provider p : Providers.getProviderList().providers()) {
@@ -667,6 +888,42 @@
"No strong SecureRandom impls available: " + property);
}
+ /**
+ * Reseeds this {@code SecureRandom} with entropy input read from its
+ * entropy source.
+ *
+ * @throws UnsupportedOperationException if the underlying provider
+ * implementation has not overridden this method.
+ *
+ * @since 9
+ */
+ public synchronized void reseed() {
+ secureRandomSpi.engineReseed(null);
+ }
+
+ /**
+ * Reseeds this {@code SecureRandom} with entropy input read from its
+ * entropy source with additional parameters.
+ * <p>
+ * Note that entropy is obtained from an entropy source. While
+ * some data in {@code params} may contain entropy, its main usage is to
+ * provide diversity.
+ *
+ * @param params extra parameters
+ * @throws UnsupportedOperationException if the underlying provider
+ * implementation has not overridden this method.
+ * @throws IllegalArgumentException if {@code params} is {@code null},
+ * illegal or unsupported by this {@code SecureRandom}
+ *
+ * @since 9
+ */
+ public synchronized void reseed(SecureRandomParameters params) {
+ if (params == null) {
+ throw new IllegalArgumentException("params cannot be null");
+ }
+ secureRandomSpi.engineReseed(params);
+ }
+
// Declare serialVersionUID to be compatible with JDK1.1
static final long serialVersionUID = 4940670005562187L;
@@ -685,7 +942,7 @@
* We know that the MessageDigest class does not implement
* java.io.Serializable. However, since this field is no longer
* used, it will always be NULL and won't affect the serialization
- * of the SecureRandom class itself.
+ * of the {@code SecureRandom} class itself.
*/
private byte[] randomBytes;
/**