Chnage to INT_MAX for NIST DRBGs. Updated documentation

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Jeffrey Walton 2017-01-01 06:57:27 -05:00
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drbg.h
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@ -44,9 +44,9 @@ public:
//! \param input the entropy to add to the generator
//! \param length the size of the input buffer
//! \throws 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 800-90C</A> requirements.
//! \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
@ -57,8 +57,8 @@ public:
//! \throws 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>input</tt> must meet <A HREF ="http://csrc.nist.gov/publications/PubsSPs.html">NIST
//! SP 800-90C</A> requirements.
//! 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
@ -75,8 +75,8 @@ public:
//! \param size the length of the buffer, in bytes
//! \throws NIST_DRBG::Err if a reseed is required
//! \throws 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.
//! \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
@ -90,28 +90,33 @@ public:
//! used to maintain internal state of <tt>V</tt> and <tt>C</tt>.
virtual unsigned int GetSeedLength() const=0;
//! \brief Provides the minimum entropy
//! \brief Provides the minimum entropy size
//! \returns 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 800-90C</A> requirements.
//! HREF="http://csrc.nist.gov/publications/PubsSPs.html">NIST SP 800-90B or SP 800-90C</A> requirements.
virtual unsigned int GetMinEntropy() const=0;
//! \brief Provides the maximum entropy
//! \brief Provides the maximum entropy size
//! \returns The maximum entropy size that can be consumed by the generator, in bytes
//! \details The equivalent class constant is <tt>MAXIMUM_ENTROPY</tt>. <tt>MAXIMUM_ENTROPY</tt> has been reduced
//! from 2<sup>35</sup> to <tt>UINT_MAX</tt> to fit the C++ unsigned int datatype.
//! \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 GetMaxEntropy() const=0;
//! \brief Provides the minimum nonce
//! \brief Provides the minimum nonce size
//! \returns The minimum nonce size recommended for the generator, in bytes
//! \details The equivalent class constant is <tt>MINIMUM_NONCE</tt>. The nonce is optional but recommended
//! \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 GetMinNonce() const=0;
//! \brief Provides the maximum nonce
//! \brief Provides the maximum nonce size
//! \returns The maximum nonce that can be consumed by the generator, in bytes
//! \details The equivalent class constant is <tt>MAXIMUM_NONCE</tt>. The nonce is optional but recommended.
//! <tt>MAXIMUM_NONCE</tt> has been reduced from 2<sup>35</sup> to <tt>UINT_MAX</tt> to fit the C++ unsigned int datatype.
//! \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 GetMaxNonce() const=0;
//! \brief Provides the maximum size of a request to GenerateBlock
@ -121,7 +126,9 @@ public:
//! \brief Provides the maximum number of requests before a reseed
//! \returns The the maximum number of requests before a reseed, in bytes
//! \details The equivalent class constant is <tt>MAXIMUM_REQUESTS_BEFORE_RESEED</tt>
//! \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 GetMaxRequestBeforeReseed() const=0;
protected:
@ -141,10 +148,9 @@ protected:
//! 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>UINT_MAX</tt> due to the limited data range of an unsigned int.
//! before a reseed. However, Hash_DRBG limits it to <tt>INT_MAX</tt> due to the limited data range of an int.
//! \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>
//! for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015)</A>
//! \since Crypto++ 5.7
template <typename HASH=SHA256, unsigned int STRENGTH=128/8, unsigned int SEEDLENGTH=440/8>
class Hash_DRBG : public NIST_DRBG
@ -156,12 +162,12 @@ public:
CRYPTOPP_CONSTANT(MINIMUM_NONCE=0)
CRYPTOPP_CONSTANT(MINIMUM_ADDITIONAL=0)
CRYPTOPP_CONSTANT(MINIMUM_PERSONALIZATION=0)
CRYPTOPP_CONSTANT(MAXIMUM_ENTROPY=UINT_MAX)
CRYPTOPP_CONSTANT(MAXIMUM_NONCE=UINT_MAX)
CRYPTOPP_CONSTANT(MAXIMUM_ADDITIONAL=UINT_MAX)
CRYPTOPP_CONSTANT(MAXIMUM_PERSONALIZATION=UINT_MAX)
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=UINT_MAX)
CRYPTOPP_CONSTANT(MAXIMUM_REQUESTS_BEFORE_RESEED=INT_MAX)
//! \brief Construct a Hash DRBG
//! \param entropy the entropy to instantiate the generator
@ -169,14 +175,16 @@ public:
//! \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 additional input buffer
//! \param personalizationLength the size of the personalization buffer
//! \throws 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 800-90C</A> requirements.
//! \details The <tt>nonce</tt> and <tt>personalization</tt> are optional byte arrays. If <tt>nonce</tt> is supplied, then it should include <tt>MINIMUM_NONCE</tt> bytes of 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 800-90C</A>.
//! 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);
@ -196,11 +204,11 @@ public:
unsigned int GetSecurityStrength() const {return SECURITY_STRENGTH;}
unsigned int GetSeedLength() const {return SEED_LENGTH;}
unsigned int GetMinEntropy() const {return MINIMUM_ENTROPY;}
unsigned int GetMaxEntropy() const {return static_cast<unsigned int>(MAXIMUM_ENTROPY);}
unsigned int GetMaxEntropy() const {return MAXIMUM_ENTROPY;}
unsigned int GetMinNonce() const {return MINIMUM_NONCE;}
unsigned int GetMaxNonce() const {return static_cast<unsigned int>(MAXIMUM_NONCE);}
unsigned int GetMaxBytesPerRequest() const {return MAXIMUM_BYTES_PER_REQUEST;} // 2^16 bytes per request
unsigned int GetMaxRequestBeforeReseed() const {return static_cast<unsigned int>(MAXIMUM_REQUESTS_BEFORE_RESEED);}
unsigned int GetMaxNonce() const {return MAXIMUM_NONCE;}
unsigned int GetMaxBytesPerRequest() const {return MAXIMUM_BYTES_PER_REQUEST;}
unsigned int GetMaxRequestBeforeReseed() const {return MAXIMUM_REQUESTS_BEFORE_RESEED;}
void IncorporateEntropy(const byte *input, size_t length)
{return DRBG_Reseed(input, length, NULL, 0);}
@ -247,11 +255,11 @@ protected:
void DRBG_Instantiate(const byte* entropy, size_t entropyLength, const byte* nonce, size_t nonceLength,
const byte* personalization, size_t personalizationLength)
{
// 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.
// 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"<22> 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");
@ -274,11 +282,11 @@ protected:
// 10.1.1.3 Reseeding a Hash_DRBG Instantiation (p.49)
void DRBG_Reseed(const byte* entropy, size_t entropyLength, const byte* additional, size_t additionaLength)
{
// 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.
// 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"<22> 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");