#include <rng.h>

Inheritance diagram for Botan::Null_RNG:

Public Member Functions
void	add_entropy (const byte[], size_t) override

template<typename T >
void	add_entropy_T (const T &t)

void	clear () override

bool	is_seeded () const override

std::string	name () const override

byte	next_byte ()

byte	next_nonzero_byte ()

secure_vector< byte >	random_vec (size_t bytes)

void	randomize (byte[], size_t) override

virtual void	randomize_with_input (byte output[], size_t output_len, const byte input[], size_t input_len)

virtual void	randomize_with_ts_input (byte output[], size_t output_len)

virtual size_t	reseed (Entropy_Sources &srcs, size_t poll_bits=BOTAN_RNG_RESEED_POLL_BITS, std::chrono::milliseconds poll_timeout=BOTAN_RNG_RESEED_DEFAULT_TIMEOUT)

virtual void	reseed_from_rng (RandomNumberGenerator &rng, size_t poll_bits=BOTAN_RNG_RESEED_POLL_BITS)

Static Public Member Functions
static RandomNumberGenerator *	make_rng ()

Detailed Description

Null/stub RNG - fails if you try to use it for anything This is not generally useful except for in certain tests

Definition at line 179 of file rng.h.

Member Function Documentation

§ add_entropy()

void Botan::Null_RNG::add_entropy	(	const byte	input[],
		size_t	length
	)

inlineoverridevirtual

Incorporate some additional data into the RNG state. For example adding nonces or timestamps from a peer's protocol message can help hedge against VM state rollback attacks. A few RNG types do not accept any externally provided input, in which case this function is a no-op.

Parameters

inputs	a byte array containg the entropy to be added
length	the length of the byte array in

Implements Botan::RandomNumberGenerator.

Definition at line 191 of file rng.h.

191 {}

§ add_entropy_T()

template<typename T >

void Botan::RandomNumberGenerator::add_entropy_T ( const T & t )

inlineinherited

Incorporate some additional data into the RNG state.

Definition at line 60 of file rng.h.

Referenced by Botan::Win32_EntropySource::poll(), Botan::Intel_Rdseed::poll(), and Botan::UnixProcessInfo_EntropySource::poll().

          {
          this->add_entropy(reinterpret_cast<const uint8_t*>(&t), sizeof(T));
          }

§ clear()

void Botan::Null_RNG::clear ( )

inlineoverridevirtual

Clear all internally held values of this RNG

Postcondition: is_seeded() == false

Implements Botan::RandomNumberGenerator.

Definition at line 184 of file rng.h.

184 {}

§ is_seeded()

bool Botan::Null_RNG::is_seeded ( ) const

inlineoverridevirtual

Check whether this RNG is seeded.

Returns: true if this RNG was already seeded, false otherwise.

Implements Botan::RandomNumberGenerator.

Definition at line 182 of file rng.h.

182 { return false; }

§ make_rng()

RandomNumberGenerator * Botan::RandomNumberGenerator::make_rng ( )

staticinherited

Create a seeded and active RNG object for general application use Added in 1.8.0 Use AutoSeeded_RNG instead

Definition at line 51 of file rng.cpp.

References Botan::Serialized_RNG::Serialized_RNG().

    {
 #if defined(BOTAN_HAS_AUTO_SEEDING_RNG)
    return new AutoSeeded_RNG;
 #else
    throw Exception("make_rng failed, no AutoSeeded_RNG in this build");
 #endif
    }

§ name()

std::string Botan::Null_RNG::name ( ) const

inlineoverridevirtual

Return the name of this RNG type

Implements Botan::RandomNumberGenerator.

Definition at line 193 of file rng.h.

193 { return "Null_RNG"; }

§ next_byte()

byte Botan::RandomNumberGenerator::next_byte ( )

inlineinherited

Return a random byte

Returns: random byte

Definition at line 139 of file rng.h.

Referenced by Botan::Blinded_Point_Multiply::blinded_multiply(), and Botan::random_prime().

          {
          byte b;
          this->randomize(&b, 1);
          return b;
          }

§ next_nonzero_byte()

byte Botan::RandomNumberGenerator::next_nonzero_byte ( )

inlineinherited

Definition at line 146 of file rng.h.

          {
          byte b = this->next_byte();
          while(b == 0)
             b = this->next_byte();
          return b;
          }

§ random_vec()

secure_vector<byte> Botan::RandomNumberGenerator::random_vec ( size_t bytes )

inlineinherited

Return a random vector

Parameters

bytes number of bytes in the result

Returns: randomized vector of length bytes

Definition at line 128 of file rng.h.

Referenced by Botan::TLS::Client_Key_Exchange::Client_Key_Exchange(), Botan::Curve25519_PrivateKey::Curve25519_PrivateKey(), Botan::PK_Decryptor::decrypt_or_random(), Botan::TLS::Session::encrypt(), Botan::KeyPair::encryption_consistency_check(), Botan::generate_bcrypt(), Botan::PSSR::make(), Botan::mceies_encrypt(), Botan::OctetString::OctetString(), Botan::pbes2_encrypt(), Botan::BigInt::randomize(), Botan::TLS::Session_Manager_In_Memory::remove_all(), Botan::TLS::Session_Manager_SQL::Session_Manager_SQL(), and Botan::KeyPair::signature_consistency_check().

          {
          secure_vector<byte> output(bytes);
          this->randomize(output.data(), output.size());
          return output;
          }

§ randomize()

void Botan::Null_RNG::randomize	(	byte	output[],
		size_t	length
	)

inlineoverridevirtual

Randomize a byte array.

Parameters

output	the byte array to hold the random output.
length	the length of the byte array output.

Implements Botan::RandomNumberGenerator.

Definition at line 186 of file rng.h.

          {
          throw Exception("Null_RNG called");
          }

§ randomize_with_input()

void Botan::RandomNumberGenerator::randomize_with_input	(	byte	output[],
		size_t	output_len,
		const byte	input[],
		size_t	input_len
	)

virtualinherited

Incorporate entropy into the RNG state then produce output. Some RNG types implement this using a single operation, default calls add_entropy + randomize in sequence.

Use this to further bind the outputs to your current process/protocol state. For instance if generating a new key for use in a session, include a session ID or other such value. See NIST SP 800-90 A, B, C series for more ideas.

Reimplemented in Botan::HMAC_DRBG, and Botan::AutoSeeded_RNG.

Definition at line 30 of file rng.cpp.

References Botan::RandomNumberGenerator::add_entropy(), and Botan::RandomNumberGenerator::randomize().

Referenced by Botan::Stateful_RNG::randomize_with_ts_input(), and Botan::RandomNumberGenerator::randomize_with_ts_input().

    {
    this->add_entropy(input, input_len);
    this->randomize(output, output_len);
    }

§ randomize_with_ts_input()

void Botan::RandomNumberGenerator::randomize_with_ts_input	(	byte	output[],
		size_t	output_len
	)

virtualinherited

This calls randomize_with_input using some timestamps as extra input.

For a stateful RNG using non-random but potentially unique data as the additional_input can help protect against problems with fork, VM state rollback, or other cases where somehow an RNG state is duplicated. If both of the duplicated RNG states later incorporate a timestamp (and the timestamps don't themselves repeat), their outputs will diverge.

Reimplemented in Botan::Stateful_RNG.

Definition at line 17 of file rng.cpp.

References Botan::OS::get_processor_timestamp(), Botan::OS::get_system_timestamp_ns(), Botan::RandomNumberGenerator::randomize_with_input(), and Botan::store_le().

Referenced by Botan::AutoSeeded_RNG::randomize().

    {
    /*
    Form additional input which is provided to the PRNG implementation
    to paramaterize the KDF output.
    */
    byte additional_input[16] = { 0 };
    store_le(OS::get_system_timestamp_ns(), additional_input);
    store_le(OS::get_processor_timestamp(), additional_input + 8);
 
    randomize_with_input(output, output_len, additional_input, sizeof(additional_input));
    }

§ reseed()

size_t Botan::RandomNumberGenerator::reseed	(	Entropy_Sources &	srcs,
		size_t	poll_bits = `BOTAN_RNG_RESEED_POLL_BITS`,
		std::chrono::milliseconds	poll_timeout = `BOTAN_RNG_RESEED_DEFAULT_TIMEOUT`
	)

virtualinherited

Poll provided sources for up to poll_bits bits of entropy or until the timeout expires. Returns estimate of the number of bits collected.

Reimplemented in Botan::Serialized_RNG, Botan::Stateful_RNG, Botan::HMAC_RNG, Botan::RDRAND_RNG, Botan::PKCS11::PKCS11_RNG, Botan::AutoSeeded_RNG, and Botan::ANSI_X931_RNG.

Definition at line 37 of file rng.cpp.

References Botan::Entropy_Sources::poll().

Referenced by Botan::Stateful_RNG::reseed().

    {
    return srcs.poll(*this, poll_bits, poll_timeout);
    }

§ reseed_from_rng()

void Botan::RandomNumberGenerator::reseed_from_rng	(	RandomNumberGenerator &	rng,
		size_t	poll_bits = `BOTAN_RNG_RESEED_POLL_BITS`
	)

virtualinherited

Reseed by reading specified bits from the RNG

Reimplemented in Botan::Stateful_RNG.

Definition at line 44 of file rng.cpp.

References Botan::RandomNumberGenerator::add_entropy(), and Botan::RandomNumberGenerator::randomize().

Referenced by botan_rng_reseed(), and Botan::Stateful_RNG::reseed_from_rng().

    {
    secure_vector<byte> buf(poll_bits / 8);
    rng.randomize(buf.data(), buf.size());
    this->add_entropy(buf.data(), buf.size());
    }

The documentation for this class was generated from the following file:

src/lib/rng/rng.h

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation

§ add_entropy()

§ add_entropy_T()

§ clear()

§ is_seeded()

§ make_rng()

§ name()

§ next_byte()

§ next_nonzero_byte()

§ random_vec()

§ randomize()

§ randomize_with_input()

§ randomize_with_ts_input()

§ reseed()

§ reseed_from_rng()