https://github.com/weidai11/cryptopp
drbg.h
// drbg.h - written and placed in public domain by Jeffrey Walton.
/// \file drbg.h
/// \brief Classes for NIST DRBGs from SP 800-90A
/// \sa <A HREF="http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-90Ar1.pdf">Recommendation
/// for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015)</A>
/// \since Crypto++ 6.0
#ifndef CRYPTOPP_NIST_DRBG_H
#define CRYPTOPP_NIST_DRBG_H
#include "cryptlib.h"
#include "secblock.h"
#include "hmac.h"
#include "sha.h"
NAMESPACE_BEGIN(CryptoPP)
/// \brief Interface for NIST DRBGs from SP 800-90A
/// \details NIST_DRBG is the base class interface for NIST DRBGs from SP 800-90A Rev 1 (June 2015)
/// \details You should reseed the generator after a fork() to avoid multiple generators
/// with the same internal state.
/// \sa <A HREF="http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-90Ar1.pdf">Recommendation
/// for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015)</A>
/// \since Crypto++ 6.0
class NIST_DRBG : public RandomNumberGenerator
{
public:
/// \brief Exception thrown when a NIST DRBG encounters an error
class Err : public Exception
{
public:
explicit Err(const std::string &c, const std::string &m)
: Exception(OTHER_ERROR, c + ": " + m) {}
};
public:
virtual ~NIST_DRBG() {}
/// \brief Determines if a generator can accept additional entropy
/// \return true
/// \details All NIST_DRBG return true
virtual bool CanIncorporateEntropy() const {return true;}
/// \brief Update RNG state with additional unpredictable values
/// \param input the entropy to add to the generator
/// \param length the size of the input buffer
/// \throw NIST_DRBG::Err if the generator is reseeded with insufficient entropy
/// \details NIST instantiation and reseed requirements demand the generator is constructed
/// with at least <tt>MINIMUM_ENTROPY</tt> entropy. The byte array for <tt>input</tt> must
/// meet <A HREF ="http://csrc.nist.gov/publications/PubsSPs.html">NIST SP 800-90B or
/// SP 800-90C</A> requirements.
virtual void IncorporateEntropy(const byte *input, size_t length)=0;
/// \brief Update RNG state with additional unpredictable values
/// \param entropy the entropy to add to the generator
/// \param entropyLength the size of the input buffer
/// \param additional additional input to add to the generator
/// \param additionaLength the size of the additional input buffer
/// \throw NIST_DRBG::Err if the generator is reseeded with insufficient entropy
/// \details IncorporateEntropy() is an overload provided to match NIST requirements. NIST
/// instantiation and reseed requirements demand the generator is constructed with at least
/// <tt>MINIMUM_ENTROPY</tt> entropy. The byte array for <tt>entropy</tt> must meet
/// <A HREF ="http://csrc.nist.gov/publications/PubsSPs.html">NIST SP 800-90B or
///! SP 800-90C</A> requirements.
virtual void IncorporateEntropy(const byte *entropy, size_t entropyLength, const byte* additional, size_t additionaLength)=0;
/// \brief Generate random array of bytes
/// \param output the byte buffer
/// \param size the length of the buffer, in bytes
/// \throw NIST_DRBG::Err if a reseed is required
/// \throw NIST_DRBG::Err if the size exceeds <tt>MAXIMUM_BYTES_PER_REQUEST</tt>
virtual void GenerateBlock(byte *output, size_t size)=0;
/// \brief Generate random array of bytes
/// \param additional additional input to add to the generator
/// \param additionaLength the size of the additional input buffer
/// \param output the byte buffer
/// \param size the length of the buffer, in bytes
/// \throw NIST_DRBG::Err if a reseed is required
/// \throw NIST_DRBG::Err if the size exceeds <tt>MAXIMUM_BYTES_PER_REQUEST</tt>
/// \details GenerateBlock() is an overload provided to match NIST requirements. The byte
/// array for <tt>additional</tt> input is optional. If present the additional randomness
/// is mixed before generating the output bytes.
virtual void GenerateBlock(const byte* additional, size_t additionaLength, byte *output, size_t size)=0;
/// \brief Provides the security strength
/// \return The security strength of the generator, in bytes
/// \details The equivalent class constant is <tt>SECURITY_STRENGTH</tt>
virtual unsigned int SecurityStrength() const=0;
/// \brief Provides the seed length
/// \return The seed size of the generator, in bytes
/// \details The equivalent class constant is <tt>SEED_LENGTH</tt>. The size is
/// used to maintain internal state of <tt>V</tt> and <tt>C</tt>.
virtual unsigned int SeedLength() const=0;
/// \brief Provides the minimum entropy size
/// \return The minimum entropy size required by the generator, in bytes
/// \details The equivalent class constant is <tt>MINIMUM_ENTROPY</tt>. All NIST DRBGs must
/// be instaniated with at least <tt>MINIMUM_ENTROPY</tt> bytes of entropy. The bytes must
/// meet <A HREF="http://csrc.nist.gov/publications/PubsSPs.html">NIST SP 800-90B or
/// SP 800-90C</A> requirements.
virtual unsigned int MinEntropyLength() const=0;
/// \brief Provides the maximum entropy size
/// \return The maximum entropy size that can be consumed by the generator, in bytes
/// \details The equivalent class constant is <tt>MAXIMUM_ENTROPY</tt>. The bytes must
/// meet <A HREF="http://csrc.nist.gov/publications/PubsSPs.html">NIST SP 800-90B or
/// SP 800-90C</A> requirements. <tt>MAXIMUM_ENTROPY</tt> has been reduced from
/// 2<sup>35</sup> to <tt>INT_MAX</tt> to fit the underlying C++ datatype.
virtual unsigned int MaxEntropyLength() const=0;
/// \brief Provides the minimum nonce size
/// \return The minimum nonce size recommended for the generator, in bytes
/// \details The equivalent class constant is <tt>MINIMUM_NONCE</tt>. If a nonce is not
/// required then <tt>MINIMUM_NONCE</tt> is 0. <tt>Hash_DRBG</tt> does not require a
/// nonce, while <tt>HMAC_DRBG</tt> and <tt>CTR_DRBG</tt> require a nonce.
virtual unsigned int MinNonceLength() const=0;
/// \brief Provides the maximum nonce size
/// \return The maximum nonce that can be consumed by the generator, in bytes
/// \details The equivalent class constant is <tt>MAXIMUM_NONCE</tt>. <tt>MAXIMUM_NONCE</tt>
/// has been reduced from 2<sup>35</sup> to <tt>INT_MAX</tt> to fit the underlying C++ datatype.
/// If a nonce is not required then <tt>MINIMUM_NONCE</tt> is 0. <tt>Hash_DRBG</tt> does not
/// require a nonce, while <tt>HMAC_DRBG</tt> and <tt>CTR_DRBG</tt> require a nonce.
virtual unsigned int MaxNonceLength() const=0;
/// \brief Provides the maximum size of a request to GenerateBlock
/// \return The maximum size of a request to GenerateBlock(), in bytes
/// \details The equivalent class constant is <tt>MAXIMUM_BYTES_PER_REQUEST</tt>
virtual unsigned int MaxBytesPerRequest() const=0;
/// \brief Provides the maximum number of requests before a reseed
/// \return The maximum number of requests before a reseed, in bytes
/// \details The equivalent class constant is <tt>MAXIMUM_REQUESTS_BEFORE_RESEED</tt>.
/// <tt>MAXIMUM_REQUESTS_BEFORE_RESEED</tt> has been reduced from 2<sup>48</sup> to <tt>INT_MAX</tt>
/// to fit the underlying C++ datatype.
virtual unsigned int MaxRequestBeforeReseed() const=0;
protected:
virtual void DRBG_Instantiate(const byte* entropy, size_t entropyLength,
const byte* nonce, size_t nonceLength, const byte* personalization, size_t personalizationLength)=0;
virtual void DRBG_Reseed(const byte* entropy, size_t entropyLength, const byte* additional, size_t additionaLength)=0;
};
// *************************************************************
/// \tparam HASH NIST approved hash derived from HashTransformation
/// \tparam STRENGTH security strength, in bytes
/// \tparam SEEDLENGTH seed length, in bytes
/// \brief Hash_DRBG from SP 800-90A Rev 1 (June 2015)
/// \details The NIST Hash DRBG is instantiated with a number of parameters. Two of the parameters,
/// Security Strength and Seed Length, depend on the hash and are specified as template parameters.
/// The remaining parameters are included in the class. The parameters and their values are listed
/// in NIST SP 800-90A Rev. 1, Table 2: Definitions for Hash-Based DRBG Mechanisms (p.38).
/// \details Some parameters have been reduce to fit C++ datatypes. For example, NIST allows upto
/// 2<sup>48</sup> requests before a reseed. However, Hash_DRBG limits it to <tt>INT_MAX</tt> due
/// to the limited data range of an int.
/// \details You should reseed the generator after a fork() to avoid multiple generators
/// with the same internal state.
/// \sa <A HREF="http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-90Ar1.pdf">Recommendation
/// for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015)</A>
/// \since Crypto++ 6.0
template <typename HASH=SHA256, unsigned int STRENGTH=128/8, unsigned int SEEDLENGTH=440/8>
class Hash_DRBG : public NIST_DRBG, public NotCopyable
{
public:
CRYPTOPP_CONSTANT(SECURITY_STRENGTH=STRENGTH);
CRYPTOPP_CONSTANT(SEED_LENGTH=SEEDLENGTH);
CRYPTOPP_CONSTANT(MINIMUM_ENTROPY=STRENGTH);
CRYPTOPP_CONSTANT(MINIMUM_NONCE=0);
CRYPTOPP_CONSTANT(MINIMUM_ADDITIONAL=0);
CRYPTOPP_CONSTANT(MINIMUM_PERSONALIZATION=0);
CRYPTOPP_CONSTANT(MAXIMUM_ENTROPY=INT_MAX);
CRYPTOPP_CONSTANT(MAXIMUM_NONCE=INT_MAX);
CRYPTOPP_CONSTANT(MAXIMUM_ADDITIONAL=INT_MAX);
CRYPTOPP_CONSTANT(MAXIMUM_PERSONALIZATION=INT_MAX);
CRYPTOPP_CONSTANT(MAXIMUM_BYTES_PER_REQUEST=65536);
CRYPTOPP_CONSTANT(MAXIMUM_REQUESTS_BEFORE_RESEED=INT_MAX);
static std::string StaticAlgorithmName() { return std::string("Hash_DRBG(") + HASH::StaticAlgorithmName() + std::string(")"); }
/// \brief Construct a Hash DRBG
/// \param entropy the entropy to instantiate the generator
/// \param entropyLength the size of the entropy buffer
/// \param nonce additional input to instantiate the generator
/// \param nonceLength the size of the nonce buffer
/// \param personalization additional input to instantiate the generator
/// \param personalizationLength the size of the personalization buffer
/// \throw NIST_DRBG::Err if the generator is instantiated with insufficient entropy
/// \details All NIST DRBGs must be instaniated with at least <tt>MINIMUM_ENTROPY</tt> bytes of entropy.
/// The byte array for <tt>entropy</tt> must meet <A HREF ="http://csrc.nist.gov/publications/PubsSPs.html">NIST
/// SP 800-90B or SP 800-90C</A> requirements.
/// \details The <tt>nonce</tt> and <tt>personalization</tt> are optional byte arrays. If <tt>nonce</tt> is supplied,
/// then it should be at least <tt>MINIMUM_NONCE</tt> bytes of entropy.
/// \details An example of instantiating a SHA256 generator is shown below.
/// The example provides more entropy than required for SHA256. The <tt>NonblockingRng</tt> meets the
/// requirements of <A HREF ="http://csrc.nist.gov/publications/PubsSPs.html">NIST SP 800-90B or SP 800-90C</A>.
/// RDRAND() and RDSEED() generators would work as well.
/// <pre>
/// SecByteBlock entropy(48), result(128);
/// NonblockingRng prng;
/// RandomNumberSource rns(prng, entropy.size(), new ArraySink(entropy, entropy.size()));
///
/// Hash_DRBG<SHA256, 128/8, 440/8> drbg(entropy, 32, entropy+32, 16);
/// drbg.GenerateBlock(result, result.size());
/// </pre>
Hash_DRBG(const byte* entropy=NULLPTR, size_t entropyLength=STRENGTH, const byte* nonce=NULLPTR,
size_t nonceLength=0, const byte* personalization=NULLPTR, size_t personalizationLength=0)
: NIST_DRBG(), m_c(SEEDLENGTH), m_v(SEEDLENGTH), m_reseed(0)
{
if (m_c.data()) // GCC analyzer warning
std::memset(m_c.data(), 0x00, m_c.size());
if (m_v.data()) // GCC analyzer warning
std::memset(m_v.data(), 0x00, m_v.size());
if (entropy != NULLPTR && entropyLength != 0)
DRBG_Instantiate(entropy, entropyLength, nonce, nonceLength, personalization, personalizationLength);
}
unsigned int SecurityStrength() const {return SECURITY_STRENGTH;}
unsigned int SeedLength() const {return SEED_LENGTH;}
unsigned int MinEntropyLength() const {return MINIMUM_ENTROPY;}
unsigned int MaxEntropyLength() const {return MAXIMUM_ENTROPY;}
unsigned int MinNonceLength() const {return MINIMUM_NONCE;}
unsigned int MaxNonceLength() const {return MAXIMUM_NONCE;}
unsigned int MaxBytesPerRequest() const {return MAXIMUM_BYTES_PER_REQUEST;}
unsigned int MaxRequestBeforeReseed() const {return MAXIMUM_REQUESTS_BEFORE_RESEED;}
void IncorporateEntropy(const byte *input, size_t length)
{return DRBG_Reseed(input, length, NULLPTR, 0);}
void IncorporateEntropy(const byte *entropy, size_t entropyLength, const byte* additional, size_t additionaLength)
{return DRBG_Reseed(entropy, entropyLength, additional, additionaLength);}
void GenerateBlock(byte *output, size_t size)
{return Hash_Generate(NULLPTR, 0, output, size);}
void GenerateBlock(const byte* additional, size_t additionaLength, byte *output, size_t size)
{return Hash_Generate(additional, additionaLength, output, size);}
std::string AlgorithmProvider() const
{/*Hack*/HASH hash; return hash.AlgorithmProvider();}
protected:
// 10.1.1.2 Instantiation of Hash_DRBG (p.39)
void DRBG_Instantiate(const byte* entropy, size_t entropyLength, const byte* nonce, size_t nonceLength,
const byte* personalization, size_t personalizationLength);
// 10.1.1.3 Reseeding a Hash_DRBG Instantiation (p.40)
void DRBG_Reseed(const byte* entropy, size_t entropyLength, const byte* additional, size_t additionaLength);
// 10.1.1.4 Generating Pseudorandom Bits Using Hash_DRBG (p.41)
void Hash_Generate(const byte* additional, size_t additionaLength, byte *output, size_t size);
// 10.3.1 Derivation Function Using a Hash Function (Hash_df) (p.49)
void Hash_Update(const byte* input1, size_t inlen1, const byte* input2, size_t inlen2,
const byte* input3, size_t inlen3, const byte* input4, size_t inlen4, byte* output, size_t outlen);
private:
HASH m_hash;
SecByteBlock m_c, m_v, m_temp;
word64 m_reseed;
};
// typedef Hash_DRBG<SHA1, 128/8, 440/8> Hash_SHA1_DRBG;
// typedef Hash_DRBG<SHA256, 128/8, 440/8> Hash_SHA256_DRBG;
// typedef Hash_DRBG<SHA384, 256/8, 888/8> Hash_SHA384_DRBG;
// typedef Hash_DRBG<SHA512, 256/8, 888/8> Hash_SHA512_DRBG;
// *************************************************************
/// \tparam HASH NIST approved hash derived from HashTransformation
/// \tparam STRENGTH security strength, in bytes
/// \tparam SEEDLENGTH seed length, in bytes
/// \brief HMAC_DRBG from SP 800-90A Rev 1 (June 2015)
/// \details The NIST HMAC DRBG is instantiated with a number of parameters. Two of the parameters,
/// Security Strength and Seed Length, depend on the hash and are specified as template parameters.
/// The remaining parameters are included in the class. The parameters and their values are listed
/// in NIST SP 800-90A Rev. 1, Table 2: Definitions for Hash-Based DRBG Mechanisms (p.38).
/// \details Some parameters have been reduce to fit C++ datatypes. For example, NIST allows upto 2<sup>48</sup> requests
/// before a reseed. However, HMAC_DRBG limits it to <tt>INT_MAX</tt> due to the limited data range of an int.
/// \details You should reseed the generator after a fork() to avoid multiple generators
/// with the same internal state.
/// \sa <A HREF="http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-90Ar1.pdf">Recommendation
/// for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015)</A>
/// \since Crypto++ 6.0
template <typename HASH=SHA256, unsigned int STRENGTH=128/8, unsigned int SEEDLENGTH=440/8>
class HMAC_DRBG : public NIST_DRBG, public NotCopyable
{
public:
CRYPTOPP_CONSTANT(SECURITY_STRENGTH=STRENGTH);
CRYPTOPP_CONSTANT(SEED_LENGTH=SEEDLENGTH);
CRYPTOPP_CONSTANT(MINIMUM_ENTROPY=STRENGTH);
CRYPTOPP_CONSTANT(MINIMUM_NONCE=0);
CRYPTOPP_CONSTANT(MINIMUM_ADDITIONAL=0);
CRYPTOPP_CONSTANT(MINIMUM_PERSONALIZATION=0);
CRYPTOPP_CONSTANT(MAXIMUM_ENTROPY=INT_MAX);
CRYPTOPP_CONSTANT(MAXIMUM_NONCE=INT_MAX);
CRYPTOPP_CONSTANT(MAXIMUM_ADDITIONAL=INT_MAX);
CRYPTOPP_CONSTANT(MAXIMUM_PERSONALIZATION=INT_MAX);
CRYPTOPP_CONSTANT(MAXIMUM_BYTES_PER_REQUEST=65536);
CRYPTOPP_CONSTANT(MAXIMUM_REQUESTS_BEFORE_RESEED=INT_MAX);
static std::string StaticAlgorithmName() { return std::string("HMAC_DRBG(") + HASH::StaticAlgorithmName() + std::string(")"); }
/// \brief Construct a HMAC DRBG
/// \param entropy the entropy to instantiate the generator
/// \param entropyLength the size of the entropy buffer
/// \param nonce additional input to instantiate the generator
/// \param nonceLength the size of the nonce buffer
/// \param personalization additional input to instantiate the generator
/// \param personalizationLength the size of the personalization buffer
/// \throw NIST_DRBG::Err if the generator is instantiated with insufficient entropy
/// \details All NIST DRBGs must be instaniated with at least <tt>MINIMUM_ENTROPY</tt> bytes of entropy.
/// The byte array for <tt>entropy</tt> must meet <A HREF ="http://csrc.nist.gov/publications/PubsSPs.html">NIST
/// SP 800-90B or SP 800-90C</A> requirements.
/// \details The <tt>nonce</tt> and <tt>personalization</tt> are optional byte arrays. If <tt>nonce</tt> is supplied,
/// then it should be at least <tt>MINIMUM_NONCE</tt> bytes of entropy.
/// \details An example of instantiating a SHA256 generator is shown below.
/// The example provides more entropy than required for SHA256. The <tt>NonblockingRng</tt> meets the
/// requirements of <A HREF ="http://csrc.nist.gov/publications/PubsSPs.html">NIST SP 800-90B or SP 800-90C</A>.
/// RDRAND() and RDSEED() generators would work as well.
/// <pre>
/// SecByteBlock entropy(48), result(128);
/// NonblockingRng prng;
/// RandomNumberSource rns(prng, entropy.size(), new ArraySink(entropy, entropy.size()));
///
/// HMAC_DRBG<SHA256, 128/8, 440/8> drbg(entropy, 32, entropy+32, 16);
/// drbg.GenerateBlock(result, result.size());
/// </pre>
HMAC_DRBG(const byte* entropy=NULLPTR, size_t entropyLength=STRENGTH, const byte* nonce=NULLPTR,
size_t nonceLength=0, const byte* personalization=NULLPTR, size_t personalizationLength=0)
: NIST_DRBG(), m_k(HASH::DIGESTSIZE), m_v(HASH::DIGESTSIZE), m_reseed(0)
{
if (m_k.data()) // GCC analyzer warning
std::memset(m_k, 0x00, m_k.size());
if (m_v.data()) // GCC analyzer warning
std::memset(m_v, 0x00, m_v.size());
if (entropy != NULLPTR && entropyLength != 0)
DRBG_Instantiate(entropy, entropyLength, nonce, nonceLength, personalization, personalizationLength);
}
unsigned int SecurityStrength() const {return SECURITY_STRENGTH;}
unsigned int SeedLength() const {return SEED_LENGTH;}
unsigned int MinEntropyLength() const {return MINIMUM_ENTROPY;}
unsigned int MaxEntropyLength() const {return MAXIMUM_ENTROPY;}
unsigned int MinNonceLength() const {return MINIMUM_NONCE;}
unsigned int MaxNonceLength() const {return MAXIMUM_NONCE;}
unsigned int MaxBytesPerRequest() const {return MAXIMUM_BYTES_PER_REQUEST;}
unsigned int MaxRequestBeforeReseed() const {return MAXIMUM_REQUESTS_BEFORE_RESEED;}
void IncorporateEntropy(const byte *input, size_t length)
{return DRBG_Reseed(input, length, NULLPTR, 0);}
void IncorporateEntropy(const byte *entropy, size_t entropyLength, const byte* additional, size_t additionaLength)
{return DRBG_Reseed(entropy, entropyLength, additional, additionaLength);}
void GenerateBlock(byte *output, size_t size)
{return HMAC_Generate(NULLPTR, 0, output, size);}
void GenerateBlock(const byte* additional, size_t additionaLength, byte *output, size_t size)
{return HMAC_Generate(additional, additionaLength, output, size);}
std::string AlgorithmProvider() const
{/*Hack*/HASH hash; return hash.AlgorithmProvider();}
protected:
// 10.1.2.3 Instantiation of HMAC_DRBG (p.45)
void DRBG_Instantiate(const byte* entropy, size_t entropyLength, const byte* nonce, size_t nonceLength,
const byte* personalization, size_t personalizationLength);
// 10.1.2.4 Reseeding a HMAC_DRBG Instantiation (p.46)
void DRBG_Reseed(const byte* entropy, size_t entropyLength, const byte* additional, size_t additionaLength);
// 10.1.2.5 Generating Pseudorandom Bits Using HMAC_DRBG (p.46)
void HMAC_Generate(const byte* additional, size_t additionaLength, byte *output, size_t size);
// 10.1.2.2 Derivation Function Using a HMAC Function (HMAC_Update) (p.44)
void HMAC_Update(const byte* input1, size_t inlen1, const byte* input2, size_t inlen2, const byte* input3, size_t inlen3);
private:
HMAC<HASH> m_hmac;
SecByteBlock m_k, m_v;
word64 m_reseed;
};
// typedef HMAC_DRBG<SHA1, 128/8, 440/8> HMAC_SHA1_DRBG;
// typedef HMAC_DRBG<SHA256, 128/8, 440/8> HMAC_SHA256_DRBG;
// typedef HMAC_DRBG<SHA384, 256/8, 888/8> HMAC_SHA384_DRBG;
// typedef HMAC_DRBG<SHA512, 256/8, 888/8> HMAC_SHA512_DRBG;
// *************************************************************
// 10.1.1.2 Instantiation of Hash_DRBG (p.39)
template <typename HASH, unsigned int STRENGTH, unsigned int SEEDLENGTH>
void Hash_DRBG<HASH, STRENGTH, SEEDLENGTH>::DRBG_Instantiate(const byte* entropy, size_t entropyLength, const byte* nonce, size_t nonceLength,
const byte* personalization, size_t personalizationLength)
{
// SP 800-90A, 8.6.3: The entropy input shall have entropy that is equal to or greater than the security
// strength of the instantiation. Additional entropy may be provided in the nonce or the optional
// personalization string during instantiation, or in the additional input during reseeding and generation,
// but this is not required and does not increase the "official" security strength of the DRBG
// instantiation that is recorded in the internal state.
CRYPTOPP_ASSERT(entropyLength >= MINIMUM_ENTROPY);
if (entropyLength < MINIMUM_ENTROPY)
throw NIST_DRBG::Err("Hash_DRBG", "Insufficient entropy during instantiate");
// SP 800-90A, Section 9, says we should throw if we have too much entropy, too large a nonce,
// or too large a persoanlization string. We warn in Debug builds, but do nothing in Release builds.
CRYPTOPP_ASSERT(entropyLength <= MAXIMUM_ENTROPY);
CRYPTOPP_ASSERT(nonceLength <= MAXIMUM_NONCE);
CRYPTOPP_ASSERT(personalizationLength <= MAXIMUM_PERSONALIZATION);
const byte zero = 0;
SecByteBlock t1(SEEDLENGTH), t2(SEEDLENGTH);
Hash_Update(entropy, entropyLength, nonce, nonceLength, personalization, personalizationLength, NULLPTR, 0, t1, t1.size());
Hash_Update(&zero, 1, t1, t1.size(), NULLPTR, 0, NULLPTR, 0, t2, t2.size());
m_v.swap(t1); m_c.swap(t2);
m_reseed = 1;
}
// 10.1.1.3 Reseeding a Hash_DRBG Instantiation (p.40)
template <typename HASH, unsigned int STRENGTH, unsigned int SEEDLENGTH>
void Hash_DRBG<HASH, STRENGTH, SEEDLENGTH>::DRBG_Reseed(const byte* entropy, size_t entropyLength, const byte* additional, size_t additionaLength)
{
// SP 800-90A, 8.6.3: The entropy input shall have entropy that is equal to or greater than the security
// strength of the instantiation. Additional entropy may be provided in the nonce or the optional
// personalization string during instantiation, or in the additional input during reseeding and generation,
// but this is not required and does not increase the "official" security strength of the DRBG
// instantiation that is recorded in the internal state..
CRYPTOPP_ASSERT(entropyLength >= MINIMUM_ENTROPY);
if (entropyLength < MINIMUM_ENTROPY)
throw NIST_DRBG::Err("Hash_DRBG", "Insufficient entropy during reseed");
// SP 800-90A, Section 9, says we should throw if we have too much entropy, too large a nonce,
// or too large a persoanlization string. We warn in Debug builds, but do nothing in Release builds.
CRYPTOPP_ASSERT(entropyLength <= MAXIMUM_ENTROPY);
CRYPTOPP_ASSERT(additionaLength <= MAXIMUM_ADDITIONAL);
const byte zero = 0, one = 1;
SecByteBlock t1(SEEDLENGTH), t2(SEEDLENGTH);
Hash_Update(&one, 1, m_v, m_v.size(), entropy, entropyLength, additional, additionaLength, t1, t1.size());
Hash_Update(&zero, 1, t1, t1.size(), NULLPTR, 0, NULLPTR, 0, t2, t2.size());
m_v.swap(t1); m_c.swap(t2);
m_reseed = 1;
}
// 10.1.1.4 Generating Pseudorandom Bits Using Hash_DRBG (p.41)
template <typename HASH, unsigned int STRENGTH, unsigned int SEEDLENGTH>
void Hash_DRBG<HASH, STRENGTH, SEEDLENGTH>::Hash_Generate(const byte* additional, size_t additionaLength, byte *output, size_t size)
{
// Step 1
if (static_cast<word64>(m_reseed) >= static_cast<word64>(MaxRequestBeforeReseed()))
throw NIST_DRBG::Err("Hash_DRBG", "Reseed required");
if (size > MaxBytesPerRequest())
throw NIST_DRBG::Err("Hash_DRBG", "Request size exceeds limit");
// SP 800-90A, Section 9, says we should throw if we have too much entropy, too large a nonce,
// or too large a persoanlization string. We warn in Debug builds, but do nothing in Release builds.
CRYPTOPP_ASSERT(additionaLength <= MAXIMUM_ADDITIONAL);
// Step 2
if (additional && additionaLength)
{
const byte two = 2;
m_temp.New(HASH::DIGESTSIZE);
m_hash.Update(&two, 1);
m_hash.Update(m_v, m_v.size());
m_hash.Update(additional, additionaLength);
m_hash.Final(m_temp);
CRYPTOPP_ASSERT(SEEDLENGTH >= HASH::DIGESTSIZE);
int carry=0, j=HASH::DIGESTSIZE-1, i=SEEDLENGTH-1;
while (j>=0)
{
carry = m_v[i] + m_temp[j] + carry;
m_v[i] = static_cast<byte>(carry);
i--; j--; carry >>= 8;
}
while (i>=0)
{
carry = m_v[i] + carry;
m_v[i] = static_cast<byte>(carry);
i--; carry >>= 8;
}
}
// Step 3
{
m_temp.Assign(m_v);
while (size)
{
m_hash.Update(m_temp, m_temp.size());
size_t count = STDMIN(size, (size_t)HASH::DIGESTSIZE);
m_hash.TruncatedFinal(output, count);
IncrementCounterByOne(m_temp, static_cast<unsigned int>(m_temp.size()));
size -= count; output += count;
}
}
// Steps 4-7
{
const byte three = 3;
m_temp.New(HASH::DIGESTSIZE);
m_hash.Update(&three, 1);
m_hash.Update(m_v, m_v.size());
m_hash.Final(m_temp);
CRYPTOPP_ASSERT(SEEDLENGTH >= HASH::DIGESTSIZE);
CRYPTOPP_ASSERT(HASH::DIGESTSIZE >= sizeof(m_reseed));
int carry=0, k=sizeof(m_reseed)-1, j=HASH::DIGESTSIZE-1, i=SEEDLENGTH-1;
while (k>=0)
{
carry = m_v[i] + m_c[i] + m_temp[j] + GetByte<word64>(BIG_ENDIAN_ORDER, m_reseed, k) + carry;
m_v[i] = static_cast<byte>(carry);
i--; j--; k--; carry >>= 8;
}
while (j>=0)
{
carry = m_v[i] + m_c[i] + m_temp[j] + carry;
m_v[i] = static_cast<byte>(carry);
i--; j--; carry >>= 8;
}
while (i>=0)
{
carry = m_v[i] + m_c[i] + carry;
m_v[i] = static_cast<byte>(carry);
i--; carry >>= 8;
}
}
m_reseed++;
}
// 10.3.1 Derivation Function Using a Hash Function (Hash_df) (p.49)
template <typename HASH, unsigned int STRENGTH, unsigned int SEEDLENGTH>
void Hash_DRBG<HASH, STRENGTH, SEEDLENGTH>::Hash_Update(const byte* input1, size_t inlen1, const byte* input2, size_t inlen2,
const byte* input3, size_t inlen3, const byte* input4, size_t inlen4, byte* output, size_t outlen)
{
byte counter = 1;
word32 bits = ConditionalByteReverse(BIG_ENDIAN_ORDER, static_cast<word32>(outlen*8));
while (outlen)
{
m_hash.Update(&counter, 1);
m_hash.Update(reinterpret_cast<const byte*>(&bits), 4);
if (input1 && inlen1)
m_hash.Update(input1, inlen1);
if (input2 && inlen2)
m_hash.Update(input2, inlen2);
if (input3 && inlen3)
m_hash.Update(input3, inlen3);
if (input4 && inlen4)
m_hash.Update(input4, inlen4);
size_t count = STDMIN(outlen, (size_t)HASH::DIGESTSIZE);
m_hash.TruncatedFinal(output, count);
output += count; outlen -= count;
counter++;
}
}
// *************************************************************
// 10.1.2.3 Instantiation of HMAC_DRBG (p.45)
template <typename HASH, unsigned int STRENGTH, unsigned int SEEDLENGTH>
void HMAC_DRBG<HASH, STRENGTH, SEEDLENGTH>::DRBG_Instantiate(const byte* entropy, size_t entropyLength, const byte* nonce, size_t nonceLength,
const byte* personalization, size_t personalizationLength)
{
// SP 800-90A, 8.6.3: The entropy input shall have entropy that is equal to or greater than the security
// strength of the instantiation. Additional entropy may be provided in the nonce or the optional
// personalization string during instantiation, or in the additional input during reseeding and generation,
// but this is not required and does not increase the "official" security strength of the DRBG
// instantiation that is recorded in the internal state.
CRYPTOPP_ASSERT(entropyLength >= MINIMUM_ENTROPY);
if (entropyLength < MINIMUM_ENTROPY)
throw NIST_DRBG::Err("HMAC_DRBG", "Insufficient entropy during instantiate");
// SP 800-90A, Section 9, says we should throw if we have too much entropy, too large a nonce,
// or too large a persoanlization string. We warn in Debug builds, but do nothing in Release builds.
CRYPTOPP_ASSERT(entropyLength <= MAXIMUM_ENTROPY);
CRYPTOPP_ASSERT(nonceLength <= MAXIMUM_NONCE);
CRYPTOPP_ASSERT(personalizationLength <= MAXIMUM_PERSONALIZATION);
std::fill(m_k.begin(), m_k.begin()+m_k.size(), byte(0));
std::fill(m_v.begin(), m_v.begin()+m_v.size(), byte(1));
HMAC_Update(entropy, entropyLength, nonce, nonceLength, personalization, personalizationLength);
m_reseed = 1;
}
// 10.1.2.4 Reseeding a HMAC_DRBG Instantiation (p.46)
template <typename HASH, unsigned int STRENGTH, unsigned int SEEDLENGTH>
void HMAC_DRBG<HASH, STRENGTH, SEEDLENGTH>::DRBG_Reseed(const byte* entropy, size_t entropyLength, const byte* additional, size_t additionaLength)
{
// SP 800-90A, 8.6.3: The entropy input shall have entropy that is equal to or greater than the security
// strength of the instantiation. Additional entropy may be provided in the nonce or the optional
// personalization string during instantiation, or in the additional input during reseeding and generation,
// but this is not required and does not increase the "official" security strength of the DRBG
// instantiation that is recorded in the internal state..
CRYPTOPP_ASSERT(entropyLength >= MINIMUM_ENTROPY);
if (entropyLength < MINIMUM_ENTROPY)
throw NIST_DRBG::Err("HMAC_DRBG", "Insufficient entropy during reseed");
// SP 800-90A, Section 9, says we should throw if we have too much entropy, too large a nonce,
// or too large a persoanlization string. We warn in Debug builds, but do nothing in Release builds.
CRYPTOPP_ASSERT(entropyLength <= MAXIMUM_ENTROPY);
CRYPTOPP_ASSERT(additionaLength <= MAXIMUM_ADDITIONAL);
HMAC_Update(entropy, entropyLength, additional, additionaLength, NULLPTR, 0);
m_reseed = 1;
}
// 10.1.2.5 Generating Pseudorandom Bits Using HMAC_DRBG (p.46)
template <typename HASH, unsigned int STRENGTH, unsigned int SEEDLENGTH>
void HMAC_DRBG<HASH, STRENGTH, SEEDLENGTH>::HMAC_Generate(const byte* additional, size_t additionaLength, byte *output, size_t size)
{
// Step 1
if (static_cast<word64>(m_reseed) >= static_cast<word64>(MaxRequestBeforeReseed()))
throw NIST_DRBG::Err("HMAC_DRBG", "Reseed required");
if (size > MaxBytesPerRequest())
throw NIST_DRBG::Err("HMAC_DRBG", "Request size exceeds limit");
// SP 800-90A, Section 9, says we should throw if we have too much entropy, too large a nonce,
// or too large a persoanlization string. We warn in Debug builds, but do nothing in Release builds.
CRYPTOPP_ASSERT(additionaLength <= MAXIMUM_ADDITIONAL);
// Step 2
if (additional && additionaLength)
HMAC_Update(additional, additionaLength, NULLPTR, 0, NULLPTR, 0);
// Step 3
m_hmac.SetKey(m_k, m_k.size());
while (size)
{
m_hmac.Update(m_v, m_v.size());
m_hmac.TruncatedFinal(m_v, m_v.size());
size_t count = STDMIN(size, (size_t)HASH::DIGESTSIZE);
std::memcpy(output, m_v, count);
size -= count; output += count;
}
HMAC_Update(additional, additionaLength, NULLPTR, 0, NULLPTR, 0);
m_reseed++;
}
// 10.1.2.2 Derivation Function Using a HMAC Function (HMAC_Update) (p.44)
template <typename HASH, unsigned int STRENGTH, unsigned int SEEDLENGTH>
void HMAC_DRBG<HASH, STRENGTH, SEEDLENGTH>::HMAC_Update(const byte* input1, size_t inlen1, const byte* input2, size_t inlen2, const byte* input3, size_t inlen3)
{
const byte zero = 0, one = 1;
// Step 1
m_hmac.SetKey(m_k, m_k.size());
m_hmac.Update(m_v, m_v.size());
m_hmac.Update(&zero, 1);
if (input1 && inlen1)
m_hmac.Update(input1, inlen1);
if (input2 && inlen2)
m_hmac.Update(input2, inlen2);
if (input3 && inlen3)
m_hmac.Update(input3, inlen3);
m_hmac.TruncatedFinal(m_k, m_k.size());
// Step 2
m_hmac.SetKey(m_k, m_k.size());
m_hmac.Update(m_v, m_v.size());
m_hmac.TruncatedFinal(m_v, m_v.size());
// Step 3
if ((inlen1 | inlen2 | inlen3) == 0)
return;
// Step 4
m_hmac.SetKey(m_k, m_k.size());
m_hmac.Update(m_v, m_v.size());
m_hmac.Update(&one, 1);
if (input1 && inlen1)
m_hmac.Update(input1, inlen1);
if (input2 && inlen2)
m_hmac.Update(input2, inlen2);
if (input3 && inlen3)
m_hmac.Update(input3, inlen3);
m_hmac.TruncatedFinal(m_k, m_k.size());
// Step 5
m_hmac.SetKey(m_k, m_k.size());
m_hmac.Update(m_v, m_v.size());
m_hmac.TruncatedFinal(m_v, m_v.size());
}
NAMESPACE_END
#endif // CRYPTOPP_NIST_DRBG_H
