File: esign.h

package info (click to toggle)
libcrypto++ 8.2.0-2
  • links: PTS
  • area: main
  • in suites: experimental
  • size: 22,780 kB
  • sloc: cpp: 105,015; sh: 7,353; asm: 5,120; makefile: 316
file content (169 lines) | stat: -rw-r--r-- 5,823 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
// esign.h - originally written and placed in the public domain by Wei Dai

/// \file esign.h
/// \brief Classes providing ESIGN signature schemes as defined in IEEE P1363a
/// \since Crypto++ 5.0

#ifndef CRYPTOPP_ESIGN_H
#define CRYPTOPP_ESIGN_H

#include "cryptlib.h"
#include "pubkey.h"
#include "integer.h"
#include "asn.h"
#include "misc.h"

NAMESPACE_BEGIN(CryptoPP)

/// \brief ESIGN trapdoor function using the public key
/// \since Crypto++ 5.0
class ESIGNFunction : public TrapdoorFunction, public ASN1CryptoMaterial<PublicKey>
{
	typedef ESIGNFunction ThisClass;

public:

	/// \brief Initialize a ESIGN public key with {n,e}
	/// \param n the modulus
	/// \param e the public exponent
	void Initialize(const Integer &n, const Integer &e)
		{m_n = n; m_e = e;}

	// PublicKey
	void BERDecode(BufferedTransformation &bt);
	void DEREncode(BufferedTransformation &bt) const;

	// CryptoMaterial
	bool Validate(RandomNumberGenerator &rng, unsigned int level) const;
	bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
	void AssignFrom(const NameValuePairs &source);

	// TrapdoorFunction
	Integer ApplyFunction(const Integer &x) const;
	Integer PreimageBound() const {return m_n;}
	Integer ImageBound() const {return Integer::Power2(GetK());}

	// non-derived
	const Integer & GetModulus() const {return m_n;}
	const Integer & GetPublicExponent() const {return m_e;}

	void SetModulus(const Integer &n) {m_n = n;}
	void SetPublicExponent(const Integer &e) {m_e = e;}

protected:
	// Covertiy finding on overflow. The library allows small values for research purposes.
	unsigned int GetK() const {return SaturatingSubtract(m_n.BitCount()/3, 1U);}

	Integer m_n, m_e;
};

/// \brief ESIGN trapdoor function using the private key
/// \since Crypto++ 5.0
class InvertibleESIGNFunction : public ESIGNFunction, public RandomizedTrapdoorFunctionInverse, public PrivateKey
{
	typedef InvertibleESIGNFunction ThisClass;

public:

	/// \brief Initialize a ESIGN private key with {n,e,p,q}
	/// \param n modulus
	/// \param e public exponent
	/// \param p first prime factor
	/// \param q second prime factor
	/// \details This Initialize() function overload initializes a private key from existing parameters.
	void Initialize(const Integer &n, const Integer &e, const Integer &p, const Integer &q)
		{m_n = n; m_e = e; m_p = p; m_q = q;}

	/// \brief Create a ESIGN private key
	/// \param rng a RandomNumberGenerator derived class
	/// \param modulusBits the size of the modulud, in bits
	/// \details 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.
	void Initialize(RandomNumberGenerator &rng, unsigned int modulusBits)
		{GenerateRandomWithKeySize(rng, modulusBits);}

	// Squash Visual Studio C4250 warning
	void Save(BufferedTransformation &bt) const
		{BEREncode(bt);}

	// Squash Visual Studio C4250 warning
	void Load(BufferedTransformation &bt)
		{BERDecode(bt);}

	void BERDecode(BufferedTransformation &bt);
	void DEREncode(BufferedTransformation &bt) const;

	Integer CalculateRandomizedInverse(RandomNumberGenerator &rng, const Integer &x) const;

	// GeneratibleCryptoMaterial
	bool Validate(RandomNumberGenerator &rng, unsigned int level) const;
	bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
	void AssignFrom(const NameValuePairs &source);
	/*! parameters: (ModulusSize) */
	void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg);

	const Integer& GetPrime1() const {return m_p;}
	const Integer& GetPrime2() const {return m_q;}

	void SetPrime1(const Integer &p) {m_p = p;}
	void SetPrime2(const Integer &q) {m_q = q;}

protected:
	Integer m_p, m_q;
};

/// \brief EMSA5 padding method
/// \tparam T Mask Generation Function
/// \since Crypto++ 5.0
template <class T>
class EMSA5Pad : public PK_DeterministicSignatureMessageEncodingMethod
{
public:
	CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() {return "EMSA5";}

	void ComputeMessageRepresentative(RandomNumberGenerator &rng,
		const byte *recoverableMessage, size_t recoverableMessageLength,
		HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
		byte *representative, size_t representativeBitLength) const
	{
		CRYPTOPP_UNUSED(rng), CRYPTOPP_UNUSED(recoverableMessage), CRYPTOPP_UNUSED(recoverableMessageLength);
		CRYPTOPP_UNUSED(messageEmpty), CRYPTOPP_UNUSED(hashIdentifier);
		SecByteBlock digest(hash.DigestSize());
		hash.Final(digest);
		size_t representativeByteLength = BitsToBytes(representativeBitLength);
		T mgf;
		mgf.GenerateAndMask(hash, representative, representativeByteLength, digest, digest.size(), false);
		if (representativeBitLength % 8 != 0)
			representative[0] = (byte)Crop(representative[0], representativeBitLength % 8);
	}
};

/// \brief EMSA5 padding method, for use with ESIGN
/// \since Crypto++ 5.0
struct P1363_EMSA5 : public SignatureStandard
{
	typedef EMSA5Pad<P1363_MGF1> SignatureMessageEncodingMethod;
};

/// \brief ESIGN keys
/// \since Crypto++ 5.0
struct ESIGN_Keys
{
	CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() {return "ESIGN";}
	typedef ESIGNFunction PublicKey;
	typedef InvertibleESIGNFunction PrivateKey;
};

/// \brief ESIGN signature scheme, IEEE P1363a
/// \tparam H HashTransformation derived class
/// \tparam STANDARD Signature encoding method
/// \since Crypto++ 5.0
template <class H, class STANDARD = P1363_EMSA5>
struct ESIGN : public TF_SS<ESIGN_Keys, STANDARD, H>
{
};

NAMESPACE_END

#endif