ext-cryptopp/gfpcrypt.h
Jeffrey Walton 399a1546de Add CRYPTOPP_ASSERT (Issue 277, CVE-2016-7420)
trap.h and CRYPTOPP_ASSERT has existed for over a year in Master. We deferred on the cut-over waiting for a minor version bump (5.7). We have to use it now due to CVE-2016-7420
2016-09-16 11:27:15 -04:00

637 lines
22 KiB
C++

#ifndef CRYPTOPP_GFPCRYPT_H
#define CRYPTOPP_GFPCRYPT_H
/** \file
Implementation of schemes based on DL over GF(p)
*/
#include "config.h"
#if CRYPTOPP_MSC_VERSION
# pragma warning(push)
# pragma warning(disable: 4189)
#endif
#include "cryptlib.h"
#include "pubkey.h"
#include "integer.h"
#include "modexppc.h"
#include "algparam.h"
#include "smartptr.h"
#include "sha.h"
#include "asn.h"
#include "hmac.h"
#include "misc.h"
NAMESPACE_BEGIN(CryptoPP)
CRYPTOPP_DLL_TEMPLATE_CLASS DL_GroupParameters<Integer>;
//! _
class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE DL_GroupParameters_IntegerBased : public ASN1CryptoMaterial<DL_GroupParameters<Integer> >
{
typedef DL_GroupParameters_IntegerBased ThisClass;
public:
void Initialize(const DL_GroupParameters_IntegerBased &params)
{Initialize(params.GetModulus(), params.GetSubgroupOrder(), params.GetSubgroupGenerator());}
void Initialize(RandomNumberGenerator &rng, unsigned int pbits)
{GenerateRandom(rng, MakeParameters("ModulusSize", (int)pbits));}
void Initialize(const Integer &p, const Integer &g)
{SetModulusAndSubgroupGenerator(p, g); SetSubgroupOrder(ComputeGroupOrder(p)/2);}
void Initialize(const Integer &p, const Integer &q, const Integer &g)
{SetModulusAndSubgroupGenerator(p, g); SetSubgroupOrder(q);}
// ASN1Object interface
void BERDecode(BufferedTransformation &bt);
void DEREncode(BufferedTransformation &bt) const;
// GeneratibleCryptoMaterial interface
/*! parameters: (ModulusSize, SubgroupOrderSize (optional)) */
void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg);
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
void AssignFrom(const NameValuePairs &source);
// DL_GroupParameters
const Integer & GetSubgroupOrder() const {return m_q;}
Integer GetGroupOrder() const {return GetFieldType() == 1 ? GetModulus()-Integer::One() : GetModulus()+Integer::One();}
bool ValidateGroup(RandomNumberGenerator &rng, unsigned int level) const;
bool ValidateElement(unsigned int level, const Integer &element, const DL_FixedBasePrecomputation<Integer> *precomp) const;
bool FastSubgroupCheckAvailable() const {return GetCofactor() == 2;}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
// Cygwin i386 crash at -O3; see .
void EncodeElement(bool reversible, const Element &element, byte *encoded) const;
unsigned int GetEncodedElementSize(bool reversible) const;
#else
void EncodeElement(bool reversible, const Element &element, byte *encoded) const
{CRYPTOPP_UNUSED(reversible); element.Encode(encoded, GetModulus().ByteCount());}
unsigned int GetEncodedElementSize(bool reversible) const
{CRYPTOPP_UNUSED(reversible); return GetModulus().ByteCount();}
#endif
Integer DecodeElement(const byte *encoded, bool checkForGroupMembership) const;
Integer ConvertElementToInteger(const Element &element) const
{return element;}
Integer GetMaxExponent() const;
static std::string CRYPTOPP_API StaticAlgorithmNamePrefix() {return "";}
OID GetAlgorithmID() const;
virtual const Integer & GetModulus() const =0;
virtual void SetModulusAndSubgroupGenerator(const Integer &p, const Integer &g) =0;
void SetSubgroupOrder(const Integer &q)
{m_q = q; ParametersChanged();}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_GroupParameters_IntegerBased() {}
#endif
protected:
Integer ComputeGroupOrder(const Integer &modulus) const
{return modulus-(GetFieldType() == 1 ? 1 : -1);}
// GF(p) = 1, GF(p^2) = 2
virtual int GetFieldType() const =0;
virtual unsigned int GetDefaultSubgroupOrderSize(unsigned int modulusSize) const;
private:
Integer m_q;
};
//! _
template <class GROUP_PRECOMP, class BASE_PRECOMP = DL_FixedBasePrecomputationImpl<CPP_TYPENAME GROUP_PRECOMP::Element> >
class CRYPTOPP_NO_VTABLE DL_GroupParameters_IntegerBasedImpl : public DL_GroupParametersImpl<GROUP_PRECOMP, BASE_PRECOMP, DL_GroupParameters_IntegerBased>
{
typedef DL_GroupParameters_IntegerBasedImpl<GROUP_PRECOMP, BASE_PRECOMP> ThisClass;
public:
typedef typename GROUP_PRECOMP::Element Element;
// GeneratibleCryptoMaterial interface
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
{return GetValueHelper<DL_GroupParameters_IntegerBased>(this, name, valueType, pValue).Assignable();}
void AssignFrom(const NameValuePairs &source)
{AssignFromHelper<DL_GroupParameters_IntegerBased>(this, source);}
// DL_GroupParameters
const DL_FixedBasePrecomputation<Element> & GetBasePrecomputation() const {return this->m_gpc;}
DL_FixedBasePrecomputation<Element> & AccessBasePrecomputation() {return this->m_gpc;}
// IntegerGroupParameters
const Integer & GetModulus() const {return this->m_groupPrecomputation.GetModulus();}
const Integer & GetGenerator() const {return this->m_gpc.GetBase(this->GetGroupPrecomputation());}
void SetModulusAndSubgroupGenerator(const Integer &p, const Integer &g) // these have to be set together
{this->m_groupPrecomputation.SetModulus(p); this->m_gpc.SetBase(this->GetGroupPrecomputation(), g); this->ParametersChanged();}
// non-inherited
bool operator==(const DL_GroupParameters_IntegerBasedImpl<GROUP_PRECOMP, BASE_PRECOMP> &rhs) const
{return GetModulus() == rhs.GetModulus() && GetGenerator() == rhs.GetGenerator() && this->GetSubgroupOrder() == rhs.GetSubgroupOrder();}
bool operator!=(const DL_GroupParameters_IntegerBasedImpl<GROUP_PRECOMP, BASE_PRECOMP> &rhs) const
{return !operator==(rhs);}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_GroupParameters_IntegerBasedImpl() {}
#endif
};
CRYPTOPP_DLL_TEMPLATE_CLASS DL_GroupParameters_IntegerBasedImpl<ModExpPrecomputation>;
//! GF(p) group parameters
class CRYPTOPP_DLL DL_GroupParameters_GFP : public DL_GroupParameters_IntegerBasedImpl<ModExpPrecomputation>
{
public:
// DL_GroupParameters
bool IsIdentity(const Integer &element) const {return element == Integer::One();}
void SimultaneousExponentiate(Element *results, const Element &base, const Integer *exponents, unsigned int exponentsCount) const;
// NameValuePairs interface
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
{
return GetValueHelper<DL_GroupParameters_IntegerBased>(this, name, valueType, pValue).Assignable();
}
// used by MQV
Element MultiplyElements(const Element &a, const Element &b) const;
Element CascadeExponentiate(const Element &element1, const Integer &exponent1, const Element &element2, const Integer &exponent2) const;
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_GroupParameters_GFP() {}
#endif
protected:
int GetFieldType() const {return 1;}
};
//! GF(p) group parameters that default to same primes
class CRYPTOPP_DLL DL_GroupParameters_GFP_DefaultSafePrime : public DL_GroupParameters_GFP
{
public:
typedef NoCofactorMultiplication DefaultCofactorOption;
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_GroupParameters_GFP_DefaultSafePrime() {}
#endif
protected:
unsigned int GetDefaultSubgroupOrderSize(unsigned int modulusSize) const {return modulusSize-1;}
};
//! GDSA algorithm
template <class T>
class DL_Algorithm_GDSA : public DL_ElgamalLikeSignatureAlgorithm<T>
{
public:
CRYPTOPP_CONSTEXPR static const char * CRYPTOPP_API StaticAlgorithmName() {return "DSA-1363";}
void Sign(const DL_GroupParameters<T> &params, const Integer &x, const Integer &k, const Integer &e, Integer &r, Integer &s) const
{
const Integer &q = params.GetSubgroupOrder();
r %= q;
Integer kInv = k.InverseMod(q);
s = (kInv * (x*r + e)) % q;
CRYPTOPP_ASSERT(!!r && !!s);
}
bool Verify(const DL_GroupParameters<T> &params, const DL_PublicKey<T> &publicKey, const Integer &e, const Integer &r, const Integer &s) const
{
const Integer &q = params.GetSubgroupOrder();
if (r>=q || r<1 || s>=q || s<1)
return false;
Integer w = s.InverseMod(q);
Integer u1 = (e * w) % q;
Integer u2 = (r * w) % q;
// verify r == (g^u1 * y^u2 mod p) mod q
return r == params.ConvertElementToInteger(publicKey.CascadeExponentiateBaseAndPublicElement(u1, u2)) % q;
}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_Algorithm_GDSA() {}
#endif
};
CRYPTOPP_DLL_TEMPLATE_CLASS DL_Algorithm_GDSA<Integer>;
//! NR algorithm
template <class T>
class DL_Algorithm_NR : public DL_ElgamalLikeSignatureAlgorithm<T>
{
public:
CRYPTOPP_CONSTEXPR static const char * CRYPTOPP_API StaticAlgorithmName() {return "NR";}
void Sign(const DL_GroupParameters<T> &params, const Integer &x, const Integer &k, const Integer &e, Integer &r, Integer &s) const
{
const Integer &q = params.GetSubgroupOrder();
r = (r + e) % q;
s = (k - x*r) % q;
CRYPTOPP_ASSERT(!!r);
}
bool Verify(const DL_GroupParameters<T> &params, const DL_PublicKey<T> &publicKey, const Integer &e, const Integer &r, const Integer &s) const
{
const Integer &q = params.GetSubgroupOrder();
if (r>=q || r<1 || s>=q)
return false;
// check r == (m_g^s * m_y^r + m) mod m_q
return r == (params.ConvertElementToInteger(publicKey.CascadeExponentiateBaseAndPublicElement(s, r)) + e) % q;
}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_Algorithm_NR() {}
#endif
};
/*! DSA public key format is defined in 7.3.3 of RFC 2459. The
private key format is defined in 12.9 of PKCS #11 v2.10. */
template <class GP>
class DL_PublicKey_GFP : public DL_PublicKeyImpl<GP>
{
public:
void Initialize(const DL_GroupParameters_IntegerBased &params, const Integer &y)
{this->AccessGroupParameters().Initialize(params); this->SetPublicElement(y);}
void Initialize(const Integer &p, const Integer &g, const Integer &y)
{this->AccessGroupParameters().Initialize(p, g); this->SetPublicElement(y);}
void Initialize(const Integer &p, const Integer &q, const Integer &g, const Integer &y)
{this->AccessGroupParameters().Initialize(p, q, g); this->SetPublicElement(y);}
// X509PublicKey
void BERDecodePublicKey(BufferedTransformation &bt, bool, size_t)
{this->SetPublicElement(Integer(bt));}
void DEREncodePublicKey(BufferedTransformation &bt) const
{this->GetPublicElement().DEREncode(bt);}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_PublicKey_GFP() {}
#endif
};
//! DL private key (in GF(p) groups)
template <class GP>
class DL_PrivateKey_GFP : public DL_PrivateKeyImpl<GP>
{
public:
void Initialize(RandomNumberGenerator &rng, unsigned int modulusBits)
{this->GenerateRandomWithKeySize(rng, modulusBits);}
void Initialize(RandomNumberGenerator &rng, const Integer &p, const Integer &g)
{this->GenerateRandom(rng, MakeParameters("Modulus", p)("SubgroupGenerator", g));}
void Initialize(RandomNumberGenerator &rng, const Integer &p, const Integer &q, const Integer &g)
{this->GenerateRandom(rng, MakeParameters("Modulus", p)("SubgroupOrder", q)("SubgroupGenerator", g));}
void Initialize(const DL_GroupParameters_IntegerBased &params, const Integer &x)
{this->AccessGroupParameters().Initialize(params); this->SetPrivateExponent(x);}
void Initialize(const Integer &p, const Integer &g, const Integer &x)
{this->AccessGroupParameters().Initialize(p, g); this->SetPrivateExponent(x);}
void Initialize(const Integer &p, const Integer &q, const Integer &g, const Integer &x)
{this->AccessGroupParameters().Initialize(p, q, g); this->SetPrivateExponent(x);}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_PrivateKey_GFP() {}
#endif
};
//! DL signing/verification keys (in GF(p) groups)
struct DL_SignatureKeys_GFP
{
typedef DL_GroupParameters_GFP GroupParameters;
typedef DL_PublicKey_GFP<GroupParameters> PublicKey;
typedef DL_PrivateKey_GFP<GroupParameters> PrivateKey;
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_SignatureKeys_GFP() {}
#endif
};
//! DL encryption/decryption keys (in GF(p) groups)
struct DL_CryptoKeys_GFP
{
typedef DL_GroupParameters_GFP_DefaultSafePrime GroupParameters;
typedef DL_PublicKey_GFP<GroupParameters> PublicKey;
typedef DL_PrivateKey_GFP<GroupParameters> PrivateKey;
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_CryptoKeys_GFP() {}
#endif
};
//! provided for backwards compatibility, this class uses the old non-standard Crypto++ key format
template <class BASE>
class DL_PublicKey_GFP_OldFormat : public BASE
{
public:
void BERDecode(BufferedTransformation &bt)
{
BERSequenceDecoder seq(bt);
Integer v1(seq);
Integer v2(seq);
Integer v3(seq);
if (seq.EndReached())
{
this->AccessGroupParameters().Initialize(v1, v1/2, v2);
this->SetPublicElement(v3);
}
else
{
Integer v4(seq);
this->AccessGroupParameters().Initialize(v1, v2, v3);
this->SetPublicElement(v4);
}
seq.MessageEnd();
}
void DEREncode(BufferedTransformation &bt) const
{
DERSequenceEncoder seq(bt);
this->GetGroupParameters().GetModulus().DEREncode(seq);
if (this->GetGroupParameters().GetCofactor() != 2)
this->GetGroupParameters().GetSubgroupOrder().DEREncode(seq);
this->GetGroupParameters().GetGenerator().DEREncode(seq);
this->GetPublicElement().DEREncode(seq);
seq.MessageEnd();
}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_PublicKey_GFP_OldFormat() {}
#endif
};
//! provided for backwards compatibility, this class uses the old non-standard Crypto++ key format
template <class BASE>
class DL_PrivateKey_GFP_OldFormat : public BASE
{
public:
void BERDecode(BufferedTransformation &bt)
{
BERSequenceDecoder seq(bt);
Integer v1(seq);
Integer v2(seq);
Integer v3(seq);
Integer v4(seq);
if (seq.EndReached())
{
this->AccessGroupParameters().Initialize(v1, v1/2, v2);
this->SetPrivateExponent(v4 % (v1/2)); // some old keys may have x >= q
}
else
{
Integer v5(seq);
this->AccessGroupParameters().Initialize(v1, v2, v3);
this->SetPrivateExponent(v5);
}
seq.MessageEnd();
}
void DEREncode(BufferedTransformation &bt) const
{
DERSequenceEncoder seq(bt);
this->GetGroupParameters().GetModulus().DEREncode(seq);
if (this->GetGroupParameters().GetCofactor() != 2)
this->GetGroupParameters().GetSubgroupOrder().DEREncode(seq);
this->GetGroupParameters().GetGenerator().DEREncode(seq);
this->GetGroupParameters().ExponentiateBase(this->GetPrivateExponent()).DEREncode(seq);
this->GetPrivateExponent().DEREncode(seq);
seq.MessageEnd();
}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_PrivateKey_GFP_OldFormat() {}
#endif
};
//! <a href="http://www.weidai.com/scan-mirror/sig.html#DSA-1363">DSA-1363</a>
template <class H>
struct GDSA : public DL_SS<
DL_SignatureKeys_GFP,
DL_Algorithm_GDSA<Integer>,
DL_SignatureMessageEncodingMethod_DSA,
H>
{
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~GDSA() {}
#endif
};
//! <a href="http://www.weidai.com/scan-mirror/sig.html#NR">NR</a>
template <class H>
struct NR : public DL_SS<
DL_SignatureKeys_GFP,
DL_Algorithm_NR<Integer>,
DL_SignatureMessageEncodingMethod_NR,
H>
{
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~NR() {}
#endif
};
//! DSA group parameters, these are GF(p) group parameters that are allowed by the DSA standard
class CRYPTOPP_DLL DL_GroupParameters_DSA : public DL_GroupParameters_GFP
{
public:
/*! also checks that the lengths of p and q are allowed by the DSA standard */
bool ValidateGroup(RandomNumberGenerator &rng, unsigned int level) const;
/*! parameters: (ModulusSize), or (Modulus, SubgroupOrder, SubgroupGenerator) */
/*! ModulusSize must be between DSA::MIN_PRIME_LENGTH and DSA::MAX_PRIME_LENGTH, and divisible by DSA::PRIME_LENGTH_MULTIPLE */
void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg);
static bool CRYPTOPP_API IsValidPrimeLength(unsigned int pbits)
{return pbits >= MIN_PRIME_LENGTH && pbits <= MAX_PRIME_LENGTH && pbits % PRIME_LENGTH_MULTIPLE == 0;}
enum {MIN_PRIME_LENGTH = 1024, MAX_PRIME_LENGTH = 3072, PRIME_LENGTH_MULTIPLE = 1024};
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_GroupParameters_DSA() {}
#endif
};
template <class H>
class DSA2;
//! DSA keys
struct DL_Keys_DSA
{
typedef DL_PublicKey_GFP<DL_GroupParameters_DSA> PublicKey;
typedef DL_PrivateKey_WithSignaturePairwiseConsistencyTest<DL_PrivateKey_GFP<DL_GroupParameters_DSA>, DSA2<SHA> > PrivateKey;
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_Keys_DSA() {}
#endif
};
//! <a href="http://en.wikipedia.org/wiki/Digital_Signature_Algorithm">DSA</a>, as specified in FIPS 186-3
// class named DSA2 instead of DSA for backwards compatibility (DSA was a non-template class)
template <class H>
class DSA2 : public DL_SS<
DL_Keys_DSA,
DL_Algorithm_GDSA<Integer>,
DL_SignatureMessageEncodingMethod_DSA,
H,
DSA2<H> >
{
public:
static std::string CRYPTOPP_API StaticAlgorithmName() {return "DSA/" + (std::string)H::StaticAlgorithmName();}
#ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
enum {MIN_PRIME_LENGTH = 1024, MAX_PRIME_LENGTH = 3072, PRIME_LENGTH_MULTIPLE = 1024};
#endif
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DSA2() {}
#endif
};
//! DSA with SHA-1, typedef'd for backwards compatibility
typedef DSA2<SHA> DSA;
CRYPTOPP_DLL_TEMPLATE_CLASS DL_PublicKey_GFP<DL_GroupParameters_DSA>;
CRYPTOPP_DLL_TEMPLATE_CLASS DL_PrivateKey_GFP<DL_GroupParameters_DSA>;
CRYPTOPP_DLL_TEMPLATE_CLASS DL_PrivateKey_WithSignaturePairwiseConsistencyTest<DL_PrivateKey_GFP<DL_GroupParameters_DSA>, DSA2<SHA> >;
//! the XOR encryption method, for use with DL-based cryptosystems
template <class MAC, bool DHAES_MODE>
class DL_EncryptionAlgorithm_Xor : public DL_SymmetricEncryptionAlgorithm
{
public:
bool ParameterSupported(const char *name) const {return strcmp(name, Name::EncodingParameters()) == 0;}
size_t GetSymmetricKeyLength(size_t plaintextLength) const
{return plaintextLength + MAC::DEFAULT_KEYLENGTH;}
size_t GetSymmetricCiphertextLength(size_t plaintextLength) const
{return plaintextLength + MAC::DIGESTSIZE;}
size_t GetMaxSymmetricPlaintextLength(size_t ciphertextLength) const
{return (unsigned int)SaturatingSubtract(ciphertextLength, (unsigned int)MAC::DIGESTSIZE);}
void SymmetricEncrypt(RandomNumberGenerator &rng, const byte *key, const byte *plaintext, size_t plaintextLength, byte *ciphertext, const NameValuePairs &parameters) const
{
CRYPTOPP_UNUSED(rng);
const byte *cipherKey = NULL, *macKey = NULL;
if (DHAES_MODE)
{
macKey = key;
cipherKey = key + MAC::DEFAULT_KEYLENGTH;
}
else
{
cipherKey = key;
macKey = key + plaintextLength;
}
ConstByteArrayParameter encodingParameters;
parameters.GetValue(Name::EncodingParameters(), encodingParameters);
if (plaintextLength) // Coverity finding
xorbuf(ciphertext, plaintext, cipherKey, plaintextLength);
MAC mac(macKey);
mac.Update(ciphertext, plaintextLength);
mac.Update(encodingParameters.begin(), encodingParameters.size());
if (DHAES_MODE)
{
byte L[8] = {0,0,0,0};
PutWord(false, BIG_ENDIAN_ORDER, L+4, word32(encodingParameters.size()));
mac.Update(L, 8);
}
mac.Final(ciphertext + plaintextLength);
}
DecodingResult SymmetricDecrypt(const byte *key, const byte *ciphertext, size_t ciphertextLength, byte *plaintext, const NameValuePairs &parameters) const
{
size_t plaintextLength = GetMaxSymmetricPlaintextLength(ciphertextLength);
const byte *cipherKey, *macKey;
if (DHAES_MODE)
{
macKey = key;
cipherKey = key + MAC::DEFAULT_KEYLENGTH;
}
else
{
cipherKey = key;
macKey = key + plaintextLength;
}
ConstByteArrayParameter encodingParameters;
parameters.GetValue(Name::EncodingParameters(), encodingParameters);
MAC mac(macKey);
mac.Update(ciphertext, plaintextLength);
mac.Update(encodingParameters.begin(), encodingParameters.size());
if (DHAES_MODE)
{
byte L[8] = {0,0,0,0};
PutWord(false, BIG_ENDIAN_ORDER, L+4, word32(encodingParameters.size()));
mac.Update(L, 8);
}
if (!mac.Verify(ciphertext + plaintextLength))
return DecodingResult();
if (plaintextLength) // Coverity finding
xorbuf(plaintext, ciphertext, cipherKey, plaintextLength);
return DecodingResult(plaintextLength);
}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_EncryptionAlgorithm_Xor() {}
#endif
};
//! _
template <class T, bool DHAES_MODE, class KDF>
class DL_KeyDerivationAlgorithm_P1363 : public DL_KeyDerivationAlgorithm<T>
{
public:
bool ParameterSupported(const char *name) const {return strcmp(name, Name::KeyDerivationParameters()) == 0;}
void Derive(const DL_GroupParameters<T> &params, byte *derivedKey, size_t derivedLength, const T &agreedElement, const T &ephemeralPublicKey, const NameValuePairs &parameters) const
{
SecByteBlock agreedSecret;
if (DHAES_MODE)
{
agreedSecret.New(params.GetEncodedElementSize(true) + params.GetEncodedElementSize(false));
params.EncodeElement(true, ephemeralPublicKey, agreedSecret);
params.EncodeElement(false, agreedElement, agreedSecret + params.GetEncodedElementSize(true));
}
else
{
agreedSecret.New(params.GetEncodedElementSize(false));
params.EncodeElement(false, agreedElement, agreedSecret);
}
ConstByteArrayParameter derivationParameters;
parameters.GetValue(Name::KeyDerivationParameters(), derivationParameters);
KDF::DeriveKey(derivedKey, derivedLength, agreedSecret, agreedSecret.size(), derivationParameters.begin(), derivationParameters.size());
}
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DL_KeyDerivationAlgorithm_P1363() {}
#endif
};
//! Discrete Log Integrated Encryption Scheme, AKA <a href="http://www.weidai.com/scan-mirror/ca.html#DLIES">DLIES</a>
template <class COFACTOR_OPTION = NoCofactorMultiplication, bool DHAES_MODE = true>
struct DLIES
: public DL_ES<
DL_CryptoKeys_GFP,
DL_KeyAgreementAlgorithm_DH<Integer, COFACTOR_OPTION>,
DL_KeyDerivationAlgorithm_P1363<Integer, DHAES_MODE, P1363_KDF2<SHA1> >,
DL_EncryptionAlgorithm_Xor<HMAC<SHA1>, DHAES_MODE>,
DLIES<> >
{
static std::string CRYPTOPP_API StaticAlgorithmName() {return "DLIES";} // TODO: fix this after name is standardized
#ifndef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY_562
virtual ~DLIES() {}
#endif
};
NAMESPACE_END
#if CRYPTOPP_MSC_VERSION
# pragma warning(pop)
#endif
#endif