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
NAMESPACE_BEGIN(CryptoPP)14 NAMESPACE_BEGIN(CryptoPP)
15
16 /// \brief Rabin trapdoor function using the public key
17 /// \since Crypto++ 2.0
18 class RabinFunction : public TrapdoorFunction, public PublicKey
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
56 class InvertibleRabinFunction : public RabinFunction, public TrapdoorFunctionInverse, public PrivateKey
57 {
58 typedef InvertibleRabinFunction ThisClass;
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.
Initialize(const Integer & n,const Integer & r,const Integer & s,const Integer & p,const Integer & q,const Integer & u)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.
Initialize(RandomNumberGenerator & rng,unsigned int keybits)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
85 Integer CalculateInverse(RandomNumberGenerator &rng, const Integer &x) const;
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) */
91 void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg);
92
GetPrime1()93 const Integer& GetPrime1() const {return m_p;}
GetPrime2()94 const Integer& GetPrime2() const {return m_q;}
GetMultiplicativeInverseOfPrime2ModPrime1()95 const Integer& GetMultiplicativeInverseOfPrime2ModPrime1() const {return m_u;}
96
SetPrime1(const Integer & p)97 void SetPrime1(const Integer &p) {m_p = p;}
SetPrime2(const Integer & q)98 void SetPrime2(const Integer &q) {m_q = q;}
SetMultiplicativeInverseOfPrime2ModPrime1(const Integer & u)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 {
StaticAlgorithmNameRabin108 static std::string StaticAlgorithmName() {return "Rabin-Crypto++Variant";}
109 typedef RabinFunction PublicKey;
110 typedef InvertibleRabinFunction PrivateKey;
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
136