Crypto++  8.2
Free C++ class library of cryptographic schemes
rabin.h
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1 // rabin.h - originally written and placed in the public domain by Wei Dai
2 
3 /// \file rabin.h
4 /// \brief Classes for Rabin encryption and signature schemes
5 
6 #ifndef CRYPTOPP_RABIN_H
7 #define CRYPTOPP_RABIN_H
8 
9 #include "cryptlib.h"
10 #include "oaep.h"
11 #include "pssr.h"
12 #include "integer.h"
13 
14 NAMESPACE_BEGIN(CryptoPP)
15 
16 /// \brief Rabin trapdoor function using the public key
17 /// \since Crypto++ 2.0
19 {
20  typedef RabinFunction ThisClass;
21 
22 public:
23 
24  /// \brief Initialize a Rabin public key
25  /// \param n the modulus
26  /// \param r element r
27  /// \param s element s
28  void Initialize(const Integer &n, const Integer &r, const Integer &s)
29  {m_n = n; m_r = r; m_s = s;}
30 
31  void BERDecode(BufferedTransformation &bt);
32  void DEREncode(BufferedTransformation &bt) const;
33 
34  Integer ApplyFunction(const Integer &x) const;
35  Integer PreimageBound() const {return m_n;}
36  Integer ImageBound() const {return m_n;}
37 
38  bool Validate(RandomNumberGenerator &rng, unsigned int level) const;
39  bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
40  void AssignFrom(const NameValuePairs &source);
41 
42  const Integer& GetModulus() const {return m_n;}
43  const Integer& GetQuadraticResidueModPrime1() const {return m_r;}
44  const Integer& GetQuadraticResidueModPrime2() const {return m_s;}
45 
46  void SetModulus(const Integer &n) {m_n = n;}
47  void SetQuadraticResidueModPrime1(const Integer &r) {m_r = r;}
48  void SetQuadraticResidueModPrime2(const Integer &s) {m_s = s;}
49 
50 protected:
51  Integer m_n, m_r, m_s;
52 };
53 
54 /// \brief Rabin trapdoor function using the private key
55 /// \since Crypto++ 2.0
57 {
59 
60 public:
61 
62  /// \brief Initialize a Rabin private key
63  /// \param n modulus
64  /// \param r element r
65  /// \param s element s
66  /// \param p first prime factor
67  /// \param q second prime factor
68  /// \param u q<sup>-1</sup> mod p
69  /// \details This Initialize() function overload initializes a private key from existing parameters.
70  void Initialize(const Integer &n, const Integer &r, const Integer &s, const Integer &p, const Integer &q, const Integer &u)
71  {m_n = n; m_r = r; m_s = s; m_p = p; m_q = q; m_u = u;}
72 
73  /// \brief Create a Rabin private key
74  /// \param rng a RandomNumberGenerator derived class
75  /// \param keybits the size of the key, in bits
76  /// \details This function overload of Initialize() creates a new private key because it
77  /// takes a RandomNumberGenerator() as a parameter. If you have an existing keypair,
78  /// then use one of the other Initialize() overloads.
79  void Initialize(RandomNumberGenerator &rng, unsigned int keybits)
80  {GenerateRandomWithKeySize(rng, keybits);}
81 
82  void BERDecode(BufferedTransformation &bt);
83  void DEREncode(BufferedTransformation &bt) const;
84 
86 
87  bool Validate(RandomNumberGenerator &rng, unsigned int level) const;
88  bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
89  void AssignFrom(const NameValuePairs &source);
90  /*! parameters: (ModulusSize) */
92 
93  const Integer& GetPrime1() const {return m_p;}
94  const Integer& GetPrime2() const {return m_q;}
95  const Integer& GetMultiplicativeInverseOfPrime2ModPrime1() const {return m_u;}
96 
97  void SetPrime1(const Integer &p) {m_p = p;}
98  void SetPrime2(const Integer &q) {m_q = q;}
99  void SetMultiplicativeInverseOfPrime2ModPrime1(const Integer &u) {m_u = u;}
100 
101 protected:
102  Integer m_p, m_q, m_u;
103 };
104 
105 /// \brief Rabin keys
106 struct Rabin
107 {
108  static std::string StaticAlgorithmName() {return "Rabin-Crypto++Variant";}
109  typedef RabinFunction PublicKey;
111 };
112 
113 /// \brief Rabin encryption scheme
114 /// \tparam STANDARD encryption standard
115 template <class STANDARD>
116 struct RabinES : public TF_ES<Rabin, STANDARD>
117 {
118 };
119 
120 /// \brief Rabin signature scheme
121 /// \tparam STANDARD signature standard
122 /// \tparam H hash transformation
123 template <class STANDARD, class H>
124 struct RabinSS : public TF_SS<Rabin, STANDARD, H>
125 {
126 };
127 
128 // More typedefs for backwards compatibility
129 class SHA1;
130 typedef RabinES<OAEP<SHA1> >::Decryptor RabinDecryptor;
131 typedef RabinES<OAEP<SHA1> >::Encryptor RabinEncryptor;
132 
133 NAMESPACE_END
134 
135 #endif
Trapdoor Function (TF) encryption scheme.
Definition: pubkey.h:2223
Integer CalculateInverse(RandomNumberGenerator &rng, const Integer &x) const
Calculates the inverse of an element.
Definition: rabin.cpp:147
Abstract base classes that provide a uniform interface to this library.
Interface for random number generators.
Definition: cryptlib.h:1383
Interface for buffered transformations.
Definition: cryptlib.h:1598
Interface for private keys.
Definition: cryptlib.h:2430
Rabin signature scheme.
Definition: rabin.h:124
Rabin trapdoor function using the public key.
Definition: rabin.h:18
Rabin encryption scheme.
Definition: rabin.h:116
Applies the inverse of the trapdoor function.
Definition: pubkey.h:178
Rabin keys.
Definition: rabin.h:106
Multiple precision integer with arithmetic operations.
Definition: integer.h:49
SHA-1 message digest.
Definition: sha.h:26
Applies the trapdoor function.
Definition: pubkey.h:125
Integer PreimageBound() const
Returns the maximum size of a message before the trapdoor function is applied.
Definition: rabin.h:35
void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg)
Definition: rabin.cpp:82
void Initialize(const Integer &n, const Integer &r, const Integer &s, const Integer &p, const Integer &q, const Integer &u)
Initialize a Rabin private key.
Definition: rabin.h:70
Classes for optimal asymmetric encryption padding.
bool Validate(RandomNumberGenerator &rng, unsigned int level) const
Check this object for errors.
Definition: rabin.cpp:190
Integer ImageBound() const
Returns the maximum size of a message after the trapdoor function is applied.
Definition: rabin.h:36
void AssignFrom(const NameValuePairs &source)
Assign values to this object.
Definition: rabin.cpp:232
void GenerateRandomWithKeySize(RandomNumberGenerator &rng, unsigned int keySize)
Generate a random key or crypto parameters.
Definition: cryptlib.cpp:811
Multiple precision integer with arithmetic operations.
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
Get a named value.
Definition: rabin.cpp:223
Interface for public keys.
Definition: cryptlib.h:2425
Crypto++ library namespace.
Rabin trapdoor function using the private key.
Definition: rabin.h:56
Classes for probablistic signature schemes.
void Initialize(const Integer &n, const Integer &r, const Integer &s)
Initialize a Rabin public key.
Definition: rabin.h:28
void Initialize(RandomNumberGenerator &rng, unsigned int keybits)
Create a Rabin private key.
Definition: rabin.h:79
Interface for retrieving values given their names.
Definition: cryptlib.h:293
Template implementing constructors for public key algorithm classes.
Definition: pubkey.h:2134
Trapdoor Function (TF) Signature Scheme.
Definition: pubkey.h:2249