Crypto++  8.8
Free C++ class library of cryptographic schemes
Public Member Functions | List of all members
InvertibleESIGNFunction Class Reference

ESIGN trapdoor function using the private key. More...

+ Inheritance diagram for InvertibleESIGNFunction:

Public Member Functions

void Initialize (const Integer &n, const Integer &e, const Integer &p, const Integer &q)
 Initialize a ESIGN private key with {n,e,p,q}. More...
 
void Initialize (RandomNumberGenerator &rng, unsigned int modulusBits)
 Create a ESIGN private key. More...
 
void Save (BufferedTransformation &bt) const
 Saves a key to a BufferedTransformation. More...
 
void Load (BufferedTransformation &bt)
 Loads a key from a BufferedTransformation. More...
 
void BERDecode (BufferedTransformation &bt)
 Decode this object from a BufferedTransformation. More...
 
void DEREncode (BufferedTransformation &bt) const
 Encode this object into a BufferedTransformation. More...
 
Integer CalculateRandomizedInverse (RandomNumberGenerator &rng, const Integer &x) const
 Applies the inverse of the trapdoor function, using random data if required. More...
 
bool Validate (RandomNumberGenerator &rng, unsigned int level) const
 Check this object for errors. More...
 
bool GetVoidValue (const char *name, const std::type_info &valueType, void *pValue) const
 Get a named value. More...
 
void AssignFrom (const NameValuePairs &source)
 Assign values to this object. More...
 
void GenerateRandom (RandomNumberGenerator &rng, const NameValuePairs &alg)
 
const IntegerGetPrime1 () const
 
const IntegerGetPrime2 () const
 
void SetPrime1 (const Integer &p)
 
void SetPrime2 (const Integer &q)
 
- Public Member Functions inherited from ESIGNFunction
void Initialize (const Integer &n, const Integer &e)
 Initialize a ESIGN public key with {n,e}. More...
 
Integer ApplyFunction (const Integer &x) const
 Applies the trapdoor. More...
 
Integer PreimageBound () const
 Returns the maximum size of a message before the trapdoor function is applied. More...
 
Integer ImageBound () const
 Returns the maximum size of a representation after the trapdoor function is applied. More...
 
const IntegerGetModulus () const
 
const IntegerGetPublicExponent () const
 
void SetModulus (const Integer &n)
 
void SetPublicExponent (const Integer &e)
 
- Public Member Functions inherited from TrapdoorFunction
Integer ApplyRandomizedFunction (RandomNumberGenerator &rng, const Integer &x) const
 Applies the trapdoor function. More...
 
bool IsRandomized () const
 Determines if the encryption algorithm is randomized. More...
 
- Public Member Functions inherited from TrapdoorFunctionBounds
virtual Integer MaxPreimage () const
 Returns the maximum size of a message before the trapdoor function is applied bound to a public key. More...
 
virtual Integer MaxImage () const
 Returns the maximum size of a representation after the trapdoor function is applied bound to a public key. More...
 
- Public Member Functions inherited from ASN1CryptoMaterial< PublicKey >
void Save (BufferedTransformation &bt) const
 DER encode ASN.1 object. More...
 
void Load (BufferedTransformation &bt)
 BER decode ASN.1 object. More...
 
- Public Member Functions inherited from ASN1Object
virtual void BEREncode (BufferedTransformation &bt) const
 Encode this object into a BufferedTransformation. More...
 
- Public Member Functions inherited from CryptoMaterial
virtual void ThrowIfInvalid (RandomNumberGenerator &rng, unsigned int level) const
 Check this object for errors. More...
 
virtual bool SupportsPrecomputation () const
 Determines whether the object supports precomputation. More...
 
virtual void Precompute (unsigned int precomputationStorage)
 Perform precomputation. More...
 
virtual void LoadPrecomputation (BufferedTransformation &storedPrecomputation)
 Retrieve previously saved precomputation. More...
 
virtual void SavePrecomputation (BufferedTransformation &storedPrecomputation) const
 Save precomputation for later use. More...
 
void DoQuickSanityCheck () const
 Perform a quick sanity check. More...
 
- Public Member Functions inherited from NameValuePairs
template<class T >
bool GetThisObject (T &object) const
 Get a copy of this object or subobject. More...
 
template<class T >
bool GetThisPointer (T *&ptr) const
 Get a pointer to this object. More...
 
template<class T >
bool GetValue (const char *name, T &value) const
 Get a named value. More...
 
template<class T >
GetValueWithDefault (const char *name, T defaultValue) const
 Get a named value. More...
 
CRYPTOPP_DLL std::string GetValueNames () const
 Get a list of value names that can be retrieved. More...
 
CRYPTOPP_DLL bool GetIntValue (const char *name, int &value) const
 Get a named value with type int. More...
 
CRYPTOPP_DLL int GetIntValueWithDefault (const char *name, int defaultValue) const
 Get a named value with type int, with default. More...
 
CRYPTOPP_DLL bool GetWord64Value (const char *name, word64 &value) const
 Get a named value with type word64. More...
 
CRYPTOPP_DLL word64 GetWord64ValueWithDefault (const char *name, word64 defaultValue) const
 Get a named value with type word64, with default. More...
 
template<class T >
void GetRequiredParameter (const char *className, const char *name, T &value) const
 Retrieves a required name/value pair. More...
 
CRYPTOPP_DLL void GetRequiredIntParameter (const char *className, const char *name, int &value) const
 Retrieves a required name/value pair. More...
 
- Public Member Functions inherited from RandomizedTrapdoorFunctionInverse
virtual bool IsRandomized () const
 Determines if the decryption algorithm is randomized. More...
 
- Public Member Functions inherited from GeneratableCryptoMaterial
void GenerateRandomWithKeySize (RandomNumberGenerator &rng, unsigned int keySize)
 Generate a random key or crypto parameters. More...
 

Additional Inherited Members

- Static Public Member Functions inherited from NameValuePairs
static CRYPTOPP_DLL void ThrowIfTypeMismatch (const char *name, const std::type_info &stored, const std::type_info &retrieving)
 Ensures an expected name and type is present. More...
 

Detailed Description

ESIGN trapdoor function using the private key.

Since
Crypto++ 5.0

Definition at line 62 of file esign.h.

Member Function Documentation

◆ Initialize() [1/2]

void InvertibleESIGNFunction::Initialize ( const Integer n,
const Integer e,
const Integer p,
const Integer q 
)
inline

Initialize a ESIGN private key with {n,e,p,q}.

Parameters
nmodulus
epublic exponent
pfirst prime factor
qsecond prime factor

This Initialize() function overload initializes a private key from existing parameters.

Definition at line 74 of file esign.h.

◆ Initialize() [2/2]

void InvertibleESIGNFunction::Initialize ( RandomNumberGenerator rng,
unsigned int  modulusBits 
)
inline

Create a ESIGN private key.

Parameters
rnga RandomNumberGenerator derived class
modulusBitsthe size of the modulud, in bits

This function overload of Initialize() creates a new private key because it takes a RandomNumberGenerator() as a parameter. If you have an existing keypair, then use one of the other Initialize() overloads.

Definition at line 83 of file esign.h.

◆ Save()

void InvertibleESIGNFunction::Save ( BufferedTransformation bt) const
inlinevirtual

Saves a key to a BufferedTransformation.

Parameters
btthe destination BufferedTransformation
Exceptions
NotImplemented

Save() writes the material to a BufferedTransformation.

If the material is a key, then the key is written with ASN.1 DER encoding. The key includes an object identifier with an algorithm id, like a subjectPublicKeyInfo.

A "raw" key without the "key info" can be saved using a key's DEREncode() method.

If a derived class does not override Save(), then the base class throws NotImplemented().

Reimplemented from CryptoMaterial.

Definition at line 87 of file esign.h.

◆ Load()

void InvertibleESIGNFunction::Load ( BufferedTransformation bt)
inlinevirtual

Loads a key from a BufferedTransformation.

Parameters
btthe source BufferedTransformation
Exceptions
KeyingErr

Load() attempts to read material from a BufferedTransformation. If the material is a key that was generated outside the library, then the following usually applies:

  • the key should be ASN.1 BER encoded
  • the key should be a "key info"

"key info" means the key should have an object identifier with an algorithm id, like a subjectPublicKeyInfo.

To read a "raw" key without the "key info", then call the key's BERDecode() method.

Note
Load() generally does not check that the key is valid. Call Validate(), if needed.

Reimplemented from CryptoMaterial.

Definition at line 91 of file esign.h.

◆ BERDecode()

void InvertibleESIGNFunction::BERDecode ( BufferedTransformation bt)
virtual

Decode this object from a BufferedTransformation.

Parameters
btBufferedTransformation object

Uses Basic Encoding Rules (BER)

Reimplemented from ESIGNFunction.

Definition at line 133 of file esign.cpp.

◆ DEREncode()

void InvertibleESIGNFunction::DEREncode ( BufferedTransformation bt) const
virtual

Encode this object into a BufferedTransformation.

Parameters
btBufferedTransformation object

Uses Distinguished Encoding Rules (DER)

Reimplemented from ESIGNFunction.

Definition at line 143 of file esign.cpp.

◆ CalculateRandomizedInverse()

Integer InvertibleESIGNFunction::CalculateRandomizedInverse ( RandomNumberGenerator rng,
const Integer x 
) const
virtual

Applies the inverse of the trapdoor function, using random data if required.

Parameters
rnga RandomNumberGenerator derived class
xthe message on which the decryption function is applied
Returns
the message x decrypted under the private key

CalculateRandomizedInverse is a generalization of decryption using the private key The RandomNumberGenerator may (or may not) be required. Derived classes must implement it.

Implements RandomizedTrapdoorFunctionInverse.

Definition at line 153 of file esign.cpp.

◆ Validate()

bool InvertibleESIGNFunction::Validate ( RandomNumberGenerator rng,
unsigned int  level 
) const
virtual

Check this object for errors.

Parameters
rnga RandomNumberGenerator for objects which use randomized testing
levelthe level of thoroughness
Returns
true if the tests succeed, false otherwise

There are four levels of thoroughness:

  • 0 - using this object won't cause a crash or exception
  • 1 - this object will probably function, and encrypt, sign, other operations correctly
  • 2 - ensure this object will function correctly, and perform reasonable security checks
  • 3 - perform reasonable security checks, and do checks that may take a long time

Level 0 does not require a RandomNumberGenerator. A NullRNG() can be used for level 0. Level 1 may not check for weak keys and such. Levels 2 and 3 are recommended.

See also
ThrowIfInvalid()

Reimplemented from ESIGNFunction.

Definition at line 184 of file esign.cpp.

◆ GetVoidValue()

bool InvertibleESIGNFunction::GetVoidValue ( const char *  name,
const std::type_info &  valueType,
void *  pValue 
) const
virtual

Get a named value.

Parameters
namethe name of the object or value to retrieve
valueTypereference to a variable that receives the value
pValuevoid pointer to a variable that receives the value
Returns
true if the value was retrieved, false otherwise

GetVoidValue() retrieves the value of name if it exists.

Note
GetVoidValue() is an internal function and should be implemented by derived classes. Users should use one of the other functions instead.
See also
GetValue(), GetValueWithDefault(), GetIntValue(), GetIntValueWithDefault(), GetRequiredParameter() and GetRequiredIntParameter()

Reimplemented from ESIGNFunction.

Definition at line 207 of file esign.cpp.

◆ AssignFrom()

void InvertibleESIGNFunction::AssignFrom ( const NameValuePairs source)
virtual

Assign values to this object.

This function can be used to create a public key from a private key.

Reimplemented from ESIGNFunction.

Definition at line 215 of file esign.cpp.

◆ GenerateRandom()

void InvertibleESIGNFunction::GenerateRandom ( RandomNumberGenerator rng,
const NameValuePairs alg 
)
virtual

parameters: (ModulusSize)

Reimplemented from GeneratableCryptoMaterial.

Definition at line 88 of file esign.cpp.


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