Added in API level 1

SecureRandom

open class SecureRandom : Random

kotlin.Any
↳	java.util.Random
	↳	java.security.SecureRandom

This class provides a cryptographically strong random number generator (RNG).

A cryptographically strong random number minimally complies with the statistical random number generator tests specified in FIPS 140-2, Security Requirements for Cryptographic Modules, 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 cryptographically strong, as described in RFC 4086: Randomness Requirements for Security.

Many 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.

A caller obtains a SecureRandom instance via the no-argument constructor or one of the getInstance methods. For example:

SecureRandom r1 = new SecureRandom();
  SecureRandom r2 = SecureRandom.getInstance("NativePRNG");
  SecureRandom r3 = SecureRandom.getInstance("DRBG",
          DrbgParameters.instantiation(128, RESEED_ONLY, null));

The third statement above returns a 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 SecureRandom until it's actually used, but the effective instantiate parameters must be determined right after it's created and getParameters() should always return the same result unchanged.

Typical callers of SecureRandom invoke the following methods to retrieve random bytes:

SecureRandom random = new SecureRandom();
  byte[] bytes = new byte[20];
  random.nextBytes(bytes);

Callers may also invoke the generateSeed method to generate a given number of seed bytes (to seed other random number generators, for example):

byte[] seed = random.generateSeed(20);

A newly created PRNG SecureRandom object is not seeded (except if it is created by SecureRandom(byte[])). The first call to nextBytes will force it to seed itself from an implementation- specific entropy source. This self-seeding will not occur if setSeed was previously called.

A SecureRandom can be reseeded at any time by calling the reseed or setSeed method. The reseed method reads entropy input from its entropy source to reseed itself. The setSeed method requires the caller to provide the seed.

Please note that reseed may not be supported by all SecureRandom implementations.

Some SecureRandom implementations may accept a SecureRandomParameters parameter in its nextBytes(byte[],java.security.SecureRandomParameters) and reseed(java.security.SecureRandomParameters) methods to further control the behavior of the methods.

Note: Depending on the implementation, the generateSeed, reseed and nextBytes methods may block as entropy is being gathered, for example, if the entropy source is /dev/random on various Unix-like operating systems.

Thread safety

SecureRandom objects are safe for use by multiple concurrent threads.

Summary

Public constructors
`SecureRandom()` Constructs a secure random number generator (RNG) implementing the default random number algorithm.
`SecureRandom(seed: ByteArray!)` Constructs a secure random number generator (RNG) implementing the default random number algorithm.

Protected constructors
`SecureRandom(secureRandomSpi: SecureRandomSpi!, provider: Provider!)` Creates a `SecureRandom` object.

Public methods
open ByteArray!	`generateSeed(numBytes: Int)` Returns the given number of seed bytes, computed using the seed generation algorithm that this class uses to seed itself.
open String!	`getAlgorithm()` Returns the name of the algorithm implemented by this `SecureRandom` object.
open static SecureRandom!	`getInstance(algorithm: String!)` Returns a `SecureRandom` object that implements the specified Random Number Generator (RNG) algorithm.
open static SecureRandom!	`getInstance(algorithm: String!, provider: String!)` Returns a `SecureRandom` object that implements the specified Random Number Generator (RNG) algorithm.
open static SecureRandom!	`getInstance(algorithm: String!, provider: Provider!)` Returns a `SecureRandom` object that implements the specified Random Number Generator (RNG) algorithm.
open static SecureRandom!	`getInstance(algorithm: String!, params: SecureRandomParameters!)` Returns a `SecureRandom` object that implements the specified Random Number Generator (RNG) algorithm and supports the specified `SecureRandomParameters` request.
open static SecureRandom!	`getInstance(algorithm: String!, params: SecureRandomParameters!, provider: String!)` Returns a `SecureRandom` object that implements the specified Random Number Generator (RNG) algorithm and supports the specified `SecureRandomParameters` request.
open static SecureRandom!	`getInstance(algorithm: String!, params: SecureRandomParameters!, provider: Provider!)` Returns a `SecureRandom` object that implements the specified Random Number Generator (RNG) algorithm and supports the specified `SecureRandomParameters` request.
open static SecureRandom!	`getInstanceStrong()` Returns a `SecureRandom` object.
open SecureRandomParameters!	`getParameters()` Returns the effective `SecureRandomParameters` for this `SecureRandom` instance.
Provider!	`getProvider()` Returns the provider of this `SecureRandom` object.
open static ByteArray!	`getSeed(numBytes: Int)` Returns the given number of seed bytes, computed using the seed generation algorithm that this class uses to seed itself.
open Unit	`nextBytes(bytes: ByteArray!)` Generates a user-specified number of random bytes.
open Unit	`nextBytes(bytes: ByteArray!, params: SecureRandomParameters!)` Generates a user-specified number of random bytes with additional parameters.
open Unit	`reseed()` Reseeds this `SecureRandom` with entropy input read from its entropy source.
open Unit	`reseed(params: SecureRandomParameters!)` Reseeds this `SecureRandom` with entropy input read from its entropy source with additional parameters.
open Unit	`setSeed(seed: ByteArray!)` Reseeds this random object with the given seed.
open Unit	`setSeed(seed: Long)` Reseeds this random object, using the eight bytes contained in the given `long seed`.
open String	`toString()` Returns a Human-readable string representation of this `SecureRandom`.

Protected methods
Int	`next(numBits: Int)` Generates an integer containing the user-specified number of pseudo-random bits (right justified, with leading zeros).

Inherited functions

From class Random

`DoubleStream!`	`doubles(streamSize: Long)` Returns a stream producing the given `streamSize` number of pseudorandom `double` values, each between zero (inclusive) and one (exclusive). A pseudorandom `double` value is generated as if it's the result of calling the method `nextDouble()`.
`DoubleStream!`	`doubles()` Returns an effectively unlimited stream of pseudorandom `double` values, each between zero (inclusive) and one (exclusive). A pseudorandom `double` value is generated as if it's the result of calling the method `nextDouble()`.
`DoubleStream!`	`doubles(streamSize: Long, randomNumberOrigin: Double, randomNumberBound: Double)` Returns a stream producing the given `streamSize` number of pseudorandom `double` values, each conforming to the given origin (inclusive) and bound (exclusive). A pseudorandom `double` value is generated as if it's the result of calling the following method with the origin and bound: <code>double nextDouble(double origin, double bound) { double r = nextDouble(); r = r * (bound - origin) + origin; if (r >= bound) // correct for rounding r = Math.nextDown(bound); return r; }</code>
`DoubleStream!`	`doubles(randomNumberOrigin: Double, randomNumberBound: Double)` Returns an effectively unlimited stream of pseudorandom `double` values, each conforming to the given origin (inclusive) and bound (exclusive). A pseudorandom `double` value is generated as if it's the result of calling the following method with the origin and bound: <code>double nextDouble(double origin, double bound) { double r = nextDouble(); r = r * (bound - origin) + origin; if (r >= bound) // correct for rounding r = Math.nextDown(bound); return r; }</code>
`IntStream!`	`ints(streamSize: Long)` Returns a stream producing the given `streamSize` number of pseudorandom `int` values. A pseudorandom `int` value is generated as if it's the result of calling the method `nextInt()`.
`IntStream!`	`ints()` Returns an effectively unlimited stream of pseudorandom `int` values. A pseudorandom `int` value is generated as if it's the result of calling the method `nextInt()`.
`IntStream!`	`ints(streamSize: Long, randomNumberOrigin: Int, randomNumberBound: Int)` Returns a stream producing the given `streamSize` number of pseudorandom `int` values, each conforming to the given origin (inclusive) and bound (exclusive). A pseudorandom `int` value is generated as if it's the result of calling the following method with the origin and bound: <code>int nextInt(int origin, int bound) { int n = bound - origin; if (n > 0) { return nextInt(n) + origin; } else { // range not representable as int int r; do { r = nextInt(); } while (r < origin \|\| r >= bound); return r; } }</code>
`IntStream!`	`ints(randomNumberOrigin: Int, randomNumberBound: Int)` Returns an effectively unlimited stream of pseudorandom `int` values, each conforming to the given origin (inclusive) and bound (exclusive). A pseudorandom `int` value is generated as if it's the result of calling the following method with the origin and bound: <code>int nextInt(int origin, int bound) { int n = bound - origin; if (n > 0) { return nextInt(n) + origin; } else { // range not representable as int int r; do { r = nextInt(); } while (r < origin \|\| r >= bound); return r; } }</code>
`LongStream!`	`longs(streamSize: Long)` Returns a stream producing the given `streamSize` number of pseudorandom `long` values. A pseudorandom `long` value is generated as if it's the result of calling the method `nextLong()`.
`LongStream!`	`longs()` Returns an effectively unlimited stream of pseudorandom `long` values. A pseudorandom `long` value is generated as if it's the result of calling the method `nextLong()`.
`LongStream!`	`longs(streamSize: Long, randomNumberOrigin: Long, randomNumberBound: Long)` Returns a stream producing the given `streamSize` number of pseudorandom `long`, each conforming to the given origin (inclusive) and bound (exclusive). A pseudorandom `long` value is generated as if it's the result of calling the following method with the origin and bound: <code>long nextLong(long origin, long bound) { long r = nextLong(); long n = bound - origin, m = n - 1; if ((n & m) == 0L) // power of two r = (r & m) + origin; else if (n > 0L) { // reject over-represented candidates for (long u = r >>> 1; // ensure nonnegative u + m - (r = u % n) < 0L; // rejection check u = nextLong() >>> 1) // retry ; r += origin; } else { // range not representable as long while (r < origin \|\| r >= bound) r = nextLong(); } return r; }</code>
`LongStream!`	`longs(randomNumberOrigin: Long, randomNumberBound: Long)` Returns an effectively unlimited stream of pseudorandom `long` values, each conforming to the given origin (inclusive) and bound (exclusive). A pseudorandom `long` value is generated as if it's the result of calling the following method with the origin and bound: <code>long nextLong(long origin, long bound) { long r = nextLong(); long n = bound - origin, m = n - 1; if ((n & m) == 0L) // power of two r = (r & m) + origin; else if (n > 0L) { // reject over-represented candidates for (long u = r >>> 1; // ensure nonnegative u + m - (r = u % n) < 0L; // rejection check u = nextLong() >>> 1) // retry ; r += origin; } else { // range not representable as long while (r < origin \|\| r >= bound) r = nextLong(); } return r; }</code>
`Boolean`	`nextBoolean()` Returns the next pseudorandom, uniformly distributed `boolean` value from this random number generator's sequence. The general contract of `nextBoolean` is that one `boolean` value is pseudorandomly generated and returned. The values `true` and `false` are produced with (approximately) equal probability.
`Double`	`nextDouble()` Returns the next pseudorandom, uniformly distributed `double` value between `0.0` and `1.0` from this random number generator's sequence. The general contract of `nextDouble` is that one `double` value, chosen (approximately) uniformly from the range `0.0d` (inclusive) to `1.0d` (exclusive), is pseudorandomly generated and returned.
`Float`	`nextFloat()` Returns the next pseudorandom, uniformly distributed `float` value between `0.0` and `1.0` from this random number generator's sequence. The general contract of `nextFloat` is that one `float` value, chosen (approximately) uniformly from the range `0.0f` (inclusive) to `1.0f` (exclusive), is pseudorandomly generated and returned. All 224 possible `float` values of the form m x 2-24, where m is a positive integer less than 224, are produced with (approximately) equal probability.
`Double`	`nextGaussian()` Returns the next pseudorandom, Gaussian ("normally") distributed `double` value with mean `0.0` and standard deviation `1.0` from this random number generator's sequence. The general contract of `nextGaussian` is that one `double` value, chosen from (approximately) the usual normal distribution with mean `0.0` and standard deviation `1.0`, is pseudorandomly generated and returned.
`Int`	`nextInt()` Returns the next pseudorandom, uniformly distributed `int` value from this random number generator's sequence. The general contract of `nextInt` is that one `int` value is pseudorandomly generated and returned. All 232 possible `int` values are produced with (approximately) equal probability.
`Int`	`nextInt(bound: Int)` Returns a pseudorandom, uniformly distributed `int` value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence. The general contract of `nextInt` is that one `int` value in the specified range is pseudorandomly generated and returned. All `bound` possible `int` values are produced with (approximately) equal probability.
`Long`	`nextLong()` Returns the next pseudorandom, uniformly distributed `long` value from this random number generator's sequence. The general contract of `nextLong` is that one `long` value is pseudorandomly generated and returned.

From class RandomGenerator

`Boolean`	`isDeprecated()` Return true if the implementation of RandomGenerator (algorithm) has been marked for deprecation.
`Double`	`nextDouble(bound: Double)` Returns a pseudorandomly chosen `double` value between zero (inclusive) and the specified bound (exclusive).
`Double`	`nextDouble(origin: Double, bound: Double)` Returns a pseudorandomly chosen `double` value between the specified origin (inclusive) and the specified bound (exclusive).
`Double`	`nextExponential()` Returns a nonnegative `double` value pseudorandomly chosen from an exponential distribution whose mean is 1.
`Float`	`nextFloat(bound: Float)` Returns a pseudorandomly chosen `float` value between zero (inclusive) and the specified bound (exclusive).
`Float`	`nextFloat(origin: Float, bound: Float)` Returns a pseudorandomly chosen `float` value between the specified origin (inclusive) and the specified bound (exclusive).
`Double`	`nextGaussian(mean: Double, stddev: Double)` Returns a `double` value pseudorandomly chosen from a Gaussian (normal) distribution with a mean and standard deviation specified by the arguments.
`Int`	`nextInt(origin: Int, bound: Int)` Returns a pseudorandomly chosen `int` value between the specified origin (inclusive) and the specified bound (exclusive).
`Long`	`nextLong(bound: Long)` Returns a pseudorandomly chosen `long` value between zero (inclusive) and the specified bound (exclusive).
`Long`	`nextLong(origin: Long, bound: Long)` Returns a pseudorandomly chosen `long` value between the specified origin (inclusive) and the specified bound (exclusive).

Public constructors

SecureRandom

Added in API level 1

SecureRandom()

Constructs a secure random number generator (RNG) implementing the default random number algorithm.

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. If none of the Providers support a RNG algorithm, then an implementation-specific default is returned.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

See the SecureRandom section in the Java Security Standard Algorithm Names Specification for information about standard RNG algorithm names.

SecureRandom

Added in API level 1

SecureRandom(seed: ByteArray!)

Constructs a secure random number generator (RNG) implementing the default random number algorithm. The SecureRandom instance is seeded with the specified seed bytes.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

See the SecureRandom section in the Java Security Standard Algorithm Names Specification for information about standard RNG algorithm names.

Parameters
`seed`	ByteArray!: the seed.

Protected constructors

SecureRandom

Added in API level 1

protected SecureRandom(
    secureRandomSpi: SecureRandomSpi!, 
    provider: Provider!)

Creates a SecureRandom object.

Parameters
`secureRandomSpi`	SecureRandomSpi!: the `SecureRandom` implementation.
`provider`	Provider!: the provider.

Public methods

generateSeed

Added in API level 1

open fun generateSeed(numBytes: Int): ByteArray!

Returns the given number of seed bytes, computed using the seed generation algorithm that this class uses to seed itself. This call may be used to seed other random number generators.

Parameters
`numBytes`	Int: the number of seed bytes to generate.

Return
`ByteArray!`	the seed bytes.

Exceptions
`java.lang.IllegalArgumentException`	if `numBytes` is negative

getAlgorithm

Added in API level 1

open fun getAlgorithm(): String!

Returns the name of the algorithm implemented by this SecureRandom object.

Return
`String!`	the name of the algorithm or `unknown` if the algorithm name cannot be determined.

getInstance

Added in API level 1

open static fun getInstance(algorithm: String!): SecureRandom!

Returns a SecureRandom object that implements the specified Random Number Generator (RNG) algorithm.

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 Provider that supports the specified algorithm is returned.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

Parameters
`algorithm`	String!: the name of the RNG algorithm. See the `SecureRandom` section in the Java Security Standard Algorithm Names Specification for information about standard RNG algorithm names.

Return
`SecureRandom!`	the new `SecureRandom` object

Exceptions
`java.security.NoSuchAlgorithmException`	if no `Provider` supports a `SecureRandomSpi` implementation for the specified algorithm
`java.lang.NullPointerException`	if `algorithm` is `null`

See Also

java.security.Provider

getInstance

Added in API level 1

open static fun getInstance(
    algorithm: String!, 
    provider: String!
): SecureRandom!

Returns a SecureRandom object that implements the specified Random Number Generator (RNG) algorithm.

A new SecureRandom object encapsulating the SecureRandomSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

Parameters
`algorithm`	String!: the name of the RNG algorithm. See the `SecureRandom` section in the Java Security Standard Algorithm Names Specification for information about standard RNG algorithm names.
`provider`	String!: the name of the provider.

Return
`SecureRandom!`	the new `SecureRandom` object

Exceptions
`java.lang.IllegalArgumentException`	if the provider name is `null` or empty
`java.security.NoSuchAlgorithmException`	if a `SecureRandomSpi` implementation for the specified algorithm is not available from the specified provider
`java.security.NoSuchProviderException`	if the specified provider is not registered in the security provider list
`java.lang.NullPointerException`	if `algorithm` is `null`

See Also

java.security.Provider

getInstance

Added in API level 1

open static fun getInstance(
    algorithm: String!, 
    provider: Provider!
): SecureRandom!

Returns a SecureRandom object that implements the specified Random Number Generator (RNG) algorithm.

A new SecureRandom object encapsulating the SecureRandomSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.

Parameters
`algorithm`	String!: the name of the RNG algorithm. See the `SecureRandom` section in the Java Security Standard Algorithm Names Specification for information about standard RNG algorithm names.
`provider`	Provider!: the provider.

Return
`SecureRandom!`	the new `SecureRandom` object

Exceptions
`java.lang.IllegalArgumentException`	if the specified provider is `null`
`java.security.NoSuchAlgorithmException`	if a `SecureRandomSpi` implementation for the specified algorithm is not available from the specified `Provider` object
`java.lang.NullPointerException`	if `algorithm` is `null`

See Also

java.security.Provider

getInstance

Added in API level 35

open static fun getInstance(
    algorithm: String!, 
    params: SecureRandomParameters!
): SecureRandom!

Returns a SecureRandom object that implements the specified Random Number Generator (RNG) algorithm and supports the specified SecureRandomParameters request.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

Parameters
`algorithm`	String!: the name of the RNG algorithm. See the `SecureRandom` section in the Java Security Standard Algorithm Names Specification for information about standard RNG algorithm names.
`params`	SecureRandomParameters!: the `SecureRandomParameters` the newly created `SecureRandom` object must support.

Return
`SecureRandom!`	the new `SecureRandom` object

Exceptions
`java.lang.IllegalArgumentException`	if the specified params is `null`
`java.security.NoSuchAlgorithmException`	if no Provider supports a `SecureRandomSpi` implementation for the specified algorithm and parameters
`java.lang.NullPointerException`	if `algorithm` is `null`

See Also

java.security.Provider

getInstance

Added in API level 35

open static fun getInstance(
    algorithm: String!, 
    params: SecureRandomParameters!, 
    provider: String!
): SecureRandom!

Returns a SecureRandom object that implements the specified Random Number Generator (RNG) algorithm and supports the specified SecureRandomParameters request.

A new SecureRandom object encapsulating the SecureRandomSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

Parameters
`algorithm`	String!: the name of the RNG algorithm. See the `SecureRandom` section in the Java Security Standard Algorithm Names Specification for information about standard RNG algorithm names.
`params`	SecureRandomParameters!: the `SecureRandomParameters` the newly created `SecureRandom` object must support.
`provider`	String!: the name of the provider.

Return
`SecureRandom!`	the new `SecureRandom` object

Exceptions
`java.lang.IllegalArgumentException`	if the provider name is `null` or empty, or params is `null`
`java.security.NoSuchAlgorithmException`	if the specified provider does not support a `SecureRandomSpi` implementation for the specified algorithm and parameters
`java.security.NoSuchProviderException`	if the specified provider is not registered in the security provider list
`java.lang.NullPointerException`	if `algorithm` is `null`

See Also

java.security.Provider

getInstance

Added in API level 35

open static fun getInstance(
    algorithm: String!, 
    params: SecureRandomParameters!, 
    provider: Provider!
): SecureRandom!

Returns a SecureRandom object that implements the specified Random Number Generator (RNG) algorithm and supports the specified SecureRandomParameters request.

Parameters
`algorithm`	String!: the name of the RNG algorithm. See the `SecureRandom` section in the Java Security Standard Algorithm Names Specification for information about standard RNG algorithm names.
`params`	SecureRandomParameters!: the `SecureRandomParameters` the newly created `SecureRandom` object must support.
`provider`	Provider!: the provider.

Return
`SecureRandom!`	the new `SecureRandom` object

Exceptions
`java.lang.IllegalArgumentException`	if the specified provider or params is `null`
`java.security.NoSuchAlgorithmException`	if the specified provider does not support a `SecureRandomSpi` implementation for the specified algorithm and parameters
`java.lang.NullPointerException`	if `algorithm` is `null`

See Also

java.security.Provider

getInstanceStrong

Added in API level 26

open static fun getInstanceStrong(): SecureRandom!

Returns a SecureRandom object. In Android this is equivalent to get a SHA1PRNG from AndroidOpenSSL. Some situations require strong random values, such as when creating high-value/long-lived secrets like RSA public/private keys. To help guide applications in selecting a suitable strong SecureRandom implementation, Java distributions include a list of known strong SecureRandom implementations in the securerandom.strongAlgorithms Security property.

Every implementation of the Java platform is required to support at least one strong SecureRandom implementation.

Return
`SecureRandom!`	a strong `SecureRandom` implementation

Exceptions
`java.security.NoSuchAlgorithmException`	if no algorithm is available

See Also

java.security.Security#getProperty(String)

getParameters

Added in API level 35

open fun getParameters(): SecureRandomParameters!

Returns the effective SecureRandomParameters for this SecureRandom instance.

The returned value can be different from the SecureRandomParameters object passed into a getInstance method, but it cannot change during the lifetime of this SecureRandom object.

A caller can use the returned value to find out what features this SecureRandom supports.

Return
`SecureRandomParameters!`	the effective `SecureRandomParameters` parameters, or `null` if no parameters were used.

See Also

java.security.SecureRandomSpi

getProvider

Added in API level 1

fun getProvider(): Provider!

Returns the provider of this SecureRandom object.

Return
`Provider!`	the provider of this `SecureRandom` object.

getSeed

Added in API level 1

open static fun getSeed(numBytes: Int): ByteArray!

Returns the given number of seed bytes, computed using the seed generation algorithm that this class uses to seed itself. This call may be used to seed other random number generators.

This method is only included for backwards compatibility. The caller is encouraged to use one of the alternative getInstance methods to obtain a SecureRandom object, and then call the generateSeed method to obtain seed bytes from that object.

Parameters
`numBytes`	Int: the number of seed bytes to generate.

Return
`ByteArray!`	the seed bytes.

Exceptions
`java.lang.IllegalArgumentException`	if `numBytes` is negative

See Also

nextBytes

Added in API level 1

open fun nextBytes(bytes: ByteArray!): Unit

Generates a user-specified number of random bytes.

Parameters
`bytes`	ByteArray!: the array to be filled in with random bytes.

Exceptions
`java.lang.NullPointerException`	if the byte array is null

nextBytes

Added in API level 35

open fun nextBytes(
    bytes: ByteArray!, 
    params: SecureRandomParameters!
): Unit

Generates a user-specified number of random bytes with additional parameters.

Parameters
`bytes`	ByteArray!: the array to be filled in with random bytes
`params`	SecureRandomParameters!: additional parameters

Exceptions
`java.lang.NullPointerException`	if `bytes` is null
`java.lang.UnsupportedOperationException`	if the underlying provider implementation has not overridden this method
`java.lang.IllegalArgumentException`	if `params` is `null`, illegal or unsupported by this `SecureRandom`

reseed

Added in API level 35

open fun reseed(): Unit

Reseeds this SecureRandom with entropy input read from its entropy source.

Exceptions
`java.lang.UnsupportedOperationException`	if the underlying provider implementation has not overridden this method.

reseed

Added in API level 35

open fun reseed(params: SecureRandomParameters!): Unit

Reseeds this SecureRandom with entropy input read from its entropy source with additional parameters.

Note that entropy is obtained from an entropy source. While some data in params may contain entropy, its main usage is to provide diversity.

Parameters
`params`	SecureRandomParameters!: extra parameters

Exceptions
`java.lang.UnsupportedOperationException`	if the underlying provider implementation has not overridden this method.
`java.lang.IllegalArgumentException`	if `params` is `null`, illegal or unsupported by this `SecureRandom`

setSeed

Added in API level 1

open fun setSeed(seed: ByteArray!): Unit

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.

A PRNG SecureRandom will not seed itself automatically if setSeed is called before any nextBytes or reseed calls. The caller should make sure that the seed argument contains enough entropy for the security of this SecureRandom.

Parameters
`seed`	ByteArray!: the seed.

See Also

#getSeed

setSeed

Added in API level 1

open fun setSeed(seed: Long): Unit

Reseeds this random object, using the eight bytes contained in the given long seed. The given seed supplements, rather than replaces, the existing seed. Thus, repeated calls are guaranteed never to reduce randomness.

This method is defined for compatibility with java.util.Random.

Parameters
`seed`	Long: the seed.

See Also

#getSeed

toString

Added in API level 1

open fun toString(): String

Returns a Human-readable string representation of this SecureRandom.

Return
`String`	the string representation

Protected methods

Added in API level 1

protected fun next(numBits: Int): Int

Generates an integer containing the user-specified number of pseudo-random bits (right justified, with leading zeros). This method overrides a java.util.Random method, and serves to provide a source of random bits to all of the methods inherited from that class (for example, nextInt, nextLong, and nextFloat).

Parameters
`bits`	random bits
`numBits`	Int: number of pseudo-random bits to be generated, where `0 <= numBits <= 32`.

Return
`Int`	an `int` containing the user-specified number of pseudo-random bits (right justified, with leading zeros).