// drbg.h - written and placed in public domain by Jeffrey Walton. // Copyright assigned to Crypto++ project. //! \file drbg.h //! \brief Classes for NIST DRBGs from SP 800-90A //! \sa Recommendation //! for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015) //! \since Crypto++ 5.7 #ifndef CRYPTOPP_NIST_DRBG_H #define CRYPTOPP_NIST_DRBG_H #include "cryptlib.h" #include "secblock.h" NAMESPACE_BEGIN(CryptoPP) //! \class NIST_DRBG //! \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) //! \sa Recommendation //! for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015) //! \since Crypto++ 5.7 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 //! \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 MINIMUM_ENTROPY //! entropy. The byte array for input must meet NIST //! SP 800-90B or SP 800-90C 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 //! \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 MINIMUM_ENTROPY entropy. //! The byte array for entropy must meet NIST //! SP 800-90B or SP 800-90C 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 //! \throws NIST_DRBG::Err if a reseed is required //! \throws NIST_DRBG::Err if the size exceeds MAXIMUM_BYTES_PER_REQUEST 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 //! \throws NIST_DRBG::Err if a reseed is required //! \throws NIST_DRBG::Err if the size exceeds MAXIMUM_BYTES_PER_REQUEST //! \details GenerateBlock() is an overload provided to match NIST requirements. The byte array for additional //! 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 //! \returns The security strength of the generator, in bytes //! \details The equivalent class constant is SECURITY_STRENGTH virtual unsigned int GetSecurityStrength() const=0; //! \brief Provides the seed length //! \returns The seed size of the generator, in bytes //! \details The equivalent class constant is SEED_LENGTH. The size is //! used to maintain internal state of V and C. virtual unsigned int GetSeedLength() const=0; //! \brief Provides the minimum entropy size //! \returns The minimum entropy size required by the generator, in bytes //! \details The equivalent class constant is MINIMUM_ENTROPY. All NIST DRBGs must be instaniated with at least //! MINIMUM_ENTROPY bytes of entropy. The bytes must meet NIST SP 800-90B or SP 800-90C requirements. virtual unsigned int GetMinEntropy() const=0; //! \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 MAXIMUM_ENTROPY. The bytes must meet NIST SP 800-90B or SP 800-90C requirements. //! MAXIMUM_ENTROPY has been reduced from 235 to INT_MAX to fit the underlying C++ datatype. virtual unsigned int GetMaxEntropy() const=0; //! \brief Provides the minimum nonce size //! \returns The minimum nonce size recommended for the generator, in bytes //! \details The equivalent class constant is MINIMUM_NONCE. If a nonce is not required then //! MINIMUM_NONCE is 0. Hash_DRBG does not require a nonce, while HMAC_DRBG //! and CTR_DRBG require a nonce. virtual unsigned int GetMinNonce() const=0; //! \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 MAXIMUM_NONCE. MAXIMUM_NONCE has been reduced from //! 235 to INT_MAX to fit the underlying C++ datatype. If a nonce is not required then //! MINIMUM_NONCE is 0. Hash_DRBG does not require a nonce, while HMAC_DRBG //! and CTR_DRBG require a nonce. virtual unsigned int GetMaxNonce() const=0; //! \brief Provides the maximum size of a request to GenerateBlock //! \returns The the maximum size of a request to GenerateBlock(), in bytes //! \details The equivalent class constant is MAXIMUM_BYTES_PER_REQUEST virtual unsigned int GetMaxBytesPerRequest() const=0; //! \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 MAXIMUM_REQUESTS_BEFORE_RESEED. //! MAXIMUM_REQUESTS_BEFORE_RESEED has been reduced from 248 to INT_MAX //! to fit the underlying C++ datatype. virtual unsigned int GetMaxRequestBeforeReseed() 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; }; // ************************************************************* //! \class Hash_DRBG //! \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 248 requests //! before a reseed. However, Hash_DRBG limits it to INT_MAX due to the limited data range of an int. //! \sa Recommendation //! for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015) //! \since Crypto++ 5.7 template 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) //! \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 //! \throws NIST_DRBG::Err if the generator is instantiated with insufficient entropy //! \details All NIST DRBGs must be instaniated with at least MINIMUM_ENTROPY bytes of entropy. //! The byte array for entropy must meet NIST //! SP 800-90B or SP 800-90C requirements. //! \details The nonce and personalization are optional byte arrays. If nonce is supplied, //! then it should be at least MINIMUM_NONCE bytes of entropy. //! \details An example of instantiating a SHA256 generator is shown below. //! The example provides more entropy than required for SHA256. The NonblockingRng meets the //! requirements of NIST SP 800-90B or SP 800-90C. //! RDRAND() and RDSEED() generators would work as well. //!
    //!    SecByteBlock entropy(48), result(128);
    //!    NonblockingRng prng;
    //!    RandomNumberSource rns(prng, entropy.size(), new ArraySink(entropy, entropy.size()));
    //!
    //!    Hash_DRBG drbg(entropy, 32, entropy+32, 16);
    //!    drbg.GenerateBlock(result, result.size());
    //! 
Hash_DRBG(const byte* entropy, size_t entropyLength=STRENGTH, const byte* nonce=NULL, size_t nonceLength=0, const byte* personalization=NULL, size_t personalizationLength=0) : NIST_DRBG(), m_c(SEEDLENGTH), m_v(SEEDLENGTH) { DRBG_Instantiate(entropy, entropyLength, nonce, nonceLength, personalization, personalizationLength); } 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 MAXIMUM_ENTROPY;} unsigned int GetMinNonce() const {return MINIMUM_NONCE;} 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);} 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(NULL, 0, output, size);} void GenerateBlock(const byte* additional, size_t additionaLength, byte *output, size_t size) {return Hash_Generate(additional, additionaLength, output, size);} 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: SecByteBlock m_c, m_v; word64 m_reseed; }; // typedef Hash_DRBG Hash_SHA1_DRBG; // typedef Hash_DRBG Hash_SHA256_DRBG; // typedef Hash_DRBG Hash_SHA384_DRBG; // typedef Hash_DRBG Hash_SHA512_DRBG; // ************************************************************* //! \class HMAC_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 248 requests //! before a reseed. However, HMAC_DRBG limits it to INT_MAX due to the limited data range of an int. //! \sa Recommendation //! for Random Number Generation Using Deterministic Random Bit Generators, Rev 1 (June 2015) //! \since Crypto++ 5.7 template 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) //! \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 //! \throws NIST_DRBG::Err if the generator is instantiated with insufficient entropy //! \details All NIST DRBGs must be instaniated with at least MINIMUM_ENTROPY bytes of entropy. //! The byte array for entropy must meet NIST //! SP 800-90B or SP 800-90C requirements. //! \details The nonce and personalization are optional byte arrays. If nonce is supplied, //! then it should be at least MINIMUM_NONCE bytes of entropy. //! \details An example of instantiating a SHA256 generator is shown below. //! The example provides more entropy than required for SHA256. The NonblockingRng meets the //! requirements of NIST SP 800-90B or SP 800-90C. //! RDRAND() and RDSEED() generators would work as well. //!
    //!    SecByteBlock entropy(48), result(128);
    //!    NonblockingRng prng;
    //!    RandomNumberSource rns(prng, entropy.size(), new ArraySink(entropy, entropy.size()));
    //!
    //!    HMAC_DRBG drbg(entropy, 32, entropy+32, 16);
    //!    drbg.GenerateBlock(result, result.size());
    //! 
HMAC_DRBG(const byte* entropy, size_t entropyLength=STRENGTH, const byte* nonce=NULL, size_t nonceLength=0, const byte* personalization=NULL, size_t personalizationLength=0) : NIST_DRBG(), m_k(HASH::DIGESTSIZE), m_v(HASH::DIGESTSIZE) { DRBG_Instantiate(entropy, entropyLength, nonce, nonceLength, personalization, personalizationLength); } 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 MAXIMUM_ENTROPY;} unsigned int GetMinNonce() const {return MINIMUM_NONCE;} 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);} 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(NULL, 0, output, size);} void GenerateBlock(const byte* additional, size_t additionaLength, byte *output, size_t size) {return HMAC_Generate(additional, additionaLength, output, size);} 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: SecByteBlock m_k, m_v; word64 m_reseed; }; // typedef HMAC_DRBG HMAC_SHA1_DRBG; // typedef HMAC_DRBG HMAC_SHA256_DRBG; // typedef HMAC_DRBG HMAC_SHA384_DRBG; // typedef HMAC_DRBG HMAC_SHA512_DRBG; // ************************************************************* // 10.1.1.2 Instantiation of Hash_DRBG (p.39) template void Hash_DRBG::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, NULL, 0, t1, t1.size()); Hash_Update(&zero, 1, t1, t1.size(), NULL, 0, NULL, 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 void Hash_DRBG::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(), NULL, 0, NULL, 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 void Hash_DRBG::Hash_Generate(const byte* additional, size_t additionaLength, byte *output, size_t size) { // Step 1 if (static_cast(m_reseed) >= static_cast(GetMaxRequestBeforeReseed())) throw NIST_DRBG::Err("Hash_DRBG", "Reseed required"); if (size > GetMaxBytesPerRequest()) 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) { HASH hash; const byte two = 2; SecByteBlock w(HASH::DIGESTSIZE); hash.Update(&two, 1); hash.Update(m_v, m_v.size()); hash.Update(additional, additionaLength); hash.Final(w); CRYPTOPP_ASSERT(SEEDLENGTH >= HASH::DIGESTSIZE); int carry=0, i=SEEDLENGTH-1, j=HASH::DIGESTSIZE-1; while(i>=0 && j>=0) { carry = m_v[i] + w[j] + carry; m_v[i] = static_cast(carry); carry >>= 8; i--; j--; } while (carry && i>=0) { carry = m_v[i] + carry; m_v[i] = static_cast(carry); carry >>= 8; i--; } } // Step 3 { HASH hash; SecByteBlock data(m_v); while (size) { hash.Update(data, data.size()); size_t count = STDMIN(size, (size_t)HASH::DIGESTSIZE); hash.TruncatedFinal(output, count); IncrementCounterByOne(data, static_cast(data.size())); output += count; size -= count; } } // Steps 4-7 { HASH hash; const byte three = 3; SecByteBlock h(HASH::DIGESTSIZE); hash.Update(&three, 1); hash.Update(m_v, m_v.size()); hash.Final(h); CRYPTOPP_ASSERT(SEEDLENGTH >= HASH::DIGESTSIZE); CRYPTOPP_ASSERT(HASH::DIGESTSIZE >= sizeof(m_reseed)); int carry=0, i=SEEDLENGTH-1, j=HASH::DIGESTSIZE-1, k=sizeof(m_reseed)-1; while(i>=0 && j>=0 && k>=0) { carry = m_v[i] + m_c[i] + h[j] + GetByte(BIG_ENDIAN_ORDER, m_reseed, k) + carry; m_v[i] = static_cast(carry); carry >>= 8; i--; j--; k--; } while(i>=0 && j>=0) { carry = m_v[i] + m_c[i] + h[j] + carry; m_v[i] = static_cast(carry); carry >>= 8; i--; j--; } while (i>=0) { carry = m_v[i] + m_c[i] + carry; m_v[i] = static_cast(carry); carry >>= 8; i--; } } m_reseed++; } // 10.3.1 Derivation Function Using a Hash Function (Hash_df) (p.49) template void Hash_DRBG::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) { HASH hash; byte counter = 1; word32 bits = ConditionalByteReverse(BIG_ENDIAN_ORDER, static_cast(outlen*8)); while (outlen) { hash.Update(&counter, 1); hash.Update(reinterpret_cast(&bits), 4); if (input1 && inlen1) hash.Update(input1, inlen1); if (input2 && inlen2) hash.Update(input2, inlen2); if (input3 && inlen3) hash.Update(input3, inlen3); if (input4 && inlen4) hash.Update(input4, inlen4); size_t count = STDMIN(outlen, (size_t)HASH::DIGESTSIZE); hash.TruncatedFinal(output, count); output += count; outlen -= count; counter++; } } // ************************************************************* // 10.1.2.3 Instantiation of HMAC_DRBG (p.45) template void HMAC_DRBG::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 void HMAC_DRBG::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, NULL, 0); m_reseed = 1; } // 10.1.2.5 Generating Pseudorandom Bits Using HMAC_DRBG (p.46) template void HMAC_DRBG::HMAC_Generate(const byte* additional, size_t additionaLength, byte *output, size_t size) { // Step 1 if (static_cast(m_reseed) >= static_cast(GetMaxRequestBeforeReseed())) throw NIST_DRBG::Err("HMAC_DRBG", "Reseed required"); if (size > GetMaxBytesPerRequest()) 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, NULL, 0, NULL, 0); // Step 3 HMAC hmac; hmac.SetKey(m_k, m_k.size()); while (size) { hmac.Update(m_v, m_v.size()); hmac.TruncatedFinal(m_v, m_v.size()); size_t count = STDMIN(size, (size_t)HASH::DIGESTSIZE); memcpy(output, m_v, count); size -= count; output += count; } HMAC_Update(additional, additionaLength, NULL, 0, NULL, 0); m_reseed++; } // 10.1.2.2 Derivation Function Using a HMAC Function (HMAC_Update) (p.44) template void HMAC_DRBG::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; HMAC hmac; // Step 1 hmac.SetKey(m_k, m_k.size()); hmac.Update(m_v, m_v.size()); hmac.Update(&zero, 1); if (input1 && inlen1) hmac.Update(input1, inlen1); if (input2 && inlen2) hmac.Update(input2, inlen2); if (input3 && inlen3) hmac.Update(input3, inlen3); hmac.TruncatedFinal(m_k, m_k.size()); // Step 2 hmac.SetKey(m_k, m_k.size()); hmac.Update(m_v, m_v.size()); hmac.TruncatedFinal(m_v, m_v.size()); // Step 3 if ((inlen1 | inlen2 | inlen3) == 0) return; // Step 4 hmac.SetKey(m_k, m_k.size()); hmac.Update(m_v, m_v.size()); hmac.Update(&one, 1); if (input1 && inlen1) hmac.Update(input1, inlen1); if (input2 && inlen2) hmac.Update(input2, inlen2); if (input3 && inlen3) hmac.Update(input3, inlen3); hmac.TruncatedFinal(m_k, m_k.size()); // Step 5 hmac.SetKey(m_k, m_k.size()); hmac.Update(m_v, m_v.size()); hmac.TruncatedFinal(m_v, m_v.size()); } NAMESPACE_END #endif // CRYPTOPP_NIST_DRBG_H