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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
// pwdbased.h - written and placed in the public domain by Wei Dai
#ifndef CRYPTOPP_PWDBASED_H
#define CRYPTOPP_PWDBASED_H
#include "cryptlib.h"
#include "hmac.h"
#include "hrtimer.h"
#include "integer.h"
NAMESPACE_BEGIN(CryptoPP)
//! abstract base class for password based key derivation function
class PasswordBasedKeyDerivationFunction
{
public:
virtual size_t MaxDerivedKeyLength() const =0;
virtual bool UsesPurposeByte() const =0;
//! derive key from password
/*! If timeInSeconds != 0, will iterate until time elapsed, as measured by ThreadUserTimer
Returns actual iteration count, which is equal to iterations if timeInSeconds == 0, and not less than iterations otherwise. */
virtual unsigned int DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *password, size_t passwordLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds=0) const =0;
};
//! PBKDF1 from PKCS #5, T should be a HashTransformation class
template <class T>
class PKCS5_PBKDF1 : public PasswordBasedKeyDerivationFunction
{
public:
size_t MaxDerivedKeyLength() const {return T::DIGESTSIZE;}
bool UsesPurposeByte() const {return false;}
// PKCS #5 says PBKDF1 should only take 8-byte salts. This implementation allows salts of any length.
unsigned int DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *password, size_t passwordLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds=0) const;
};
//! PBKDF2 from PKCS #5, T should be a HashTransformation class
template <class T>
class PKCS5_PBKDF2_HMAC : public PasswordBasedKeyDerivationFunction
{
public:
size_t MaxDerivedKeyLength() const {return 0xffffffffU;} // should multiply by T::DIGESTSIZE, but gets overflow that way
bool UsesPurposeByte() const {return false;}
unsigned int DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *password, size_t passwordLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds=0) const;
};
/*
class PBKDF2Params
{
public:
SecByteBlock m_salt;
unsigned int m_interationCount;
ASNOptional<ASNUnsignedWrapper<word32> > m_keyLength;
};
*/
template <class T>
unsigned int PKCS5_PBKDF1<T>::DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *password, size_t passwordLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds) const
{
assert(derivedLen <= MaxDerivedKeyLength());
assert(iterations > 0 || timeInSeconds > 0);
if (!iterations)
iterations = 1;
T hash;
hash.Update(password, passwordLen);
hash.Update(salt, saltLen);
SecByteBlock buffer(hash.DigestSize());
hash.Final(buffer);
unsigned int i;
ThreadUserTimer timer;
if (timeInSeconds)
timer.StartTimer();
for (i=1; i<iterations || (timeInSeconds && (i%128!=0 || timer.ElapsedTimeAsDouble() < timeInSeconds)); i++)
hash.CalculateDigest(buffer, buffer, buffer.size());
memcpy(derived, buffer, derivedLen);
return i;
}
template <class T>
unsigned int PKCS5_PBKDF2_HMAC<T>::DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *password, size_t passwordLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds) const
{
assert(derivedLen <= MaxDerivedKeyLength());
assert(iterations > 0 || timeInSeconds > 0);
if (!iterations)
iterations = 1;
HMAC<T> hmac(password, passwordLen);
SecByteBlock buffer(hmac.DigestSize());
ThreadUserTimer timer;
unsigned int i=1;
while (derivedLen > 0)
{
hmac.Update(salt, saltLen);
unsigned int j;
for (j=0; j<4; j++)
{
byte b = byte(i >> ((3-j)*8));
hmac.Update(&b, 1);
}
hmac.Final(buffer);
size_t segmentLen = STDMIN(derivedLen, buffer.size());
memcpy(derived, buffer, segmentLen);
if (timeInSeconds)
{
timeInSeconds = timeInSeconds / ((derivedLen + buffer.size() - 1) / buffer.size());
timer.StartTimer();
}
for (j=1; j<iterations || (timeInSeconds && (j%128!=0 || timer.ElapsedTimeAsDouble() < timeInSeconds)); j++)
{
hmac.CalculateDigest(buffer, buffer, buffer.size());
xorbuf(derived, buffer, segmentLen);
}
if (timeInSeconds)
{
iterations = j;
timeInSeconds = 0;
}
derived += segmentLen;
derivedLen -= segmentLen;
i++;
}
return iterations;
}
//! PBKDF from PKCS #12, appendix B, T should be a HashTransformation class
template <class T>
class PKCS12_PBKDF : public PasswordBasedKeyDerivationFunction
{
public:
size_t MaxDerivedKeyLength() const {return size_t(0)-1;}
bool UsesPurposeByte() const {return true;}
unsigned int DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *password, size_t passwordLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds) const;
};
template <class T>
unsigned int PKCS12_PBKDF<T>::DeriveKey(byte *derived, size_t derivedLen, byte purpose, const byte *password, size_t passwordLen, const byte *salt, size_t saltLen, unsigned int iterations, double timeInSeconds) const
{
assert(derivedLen <= MaxDerivedKeyLength());
assert(iterations > 0 || timeInSeconds > 0);
if (!iterations)
iterations = 1;
const size_t v = T::BLOCKSIZE; // v is in bytes rather than bits as in PKCS #12
const size_t DLen = v, SLen = RoundUpToMultipleOf(saltLen, v);
const size_t PLen = RoundUpToMultipleOf(passwordLen, v), ILen = SLen + PLen;
SecByteBlock buffer(DLen + SLen + PLen);
byte *D = buffer, *S = buffer+DLen, *P = buffer+DLen+SLen, *I = S;
memset(D, purpose, DLen);
size_t i;
for (i=0; i<SLen; i++)
S[i] = salt[i % saltLen];
for (i=0; i<PLen; i++)
P[i] = password[i % passwordLen];
T hash;
SecByteBlock Ai(T::DIGESTSIZE), B(v);
ThreadUserTimer timer;
while (derivedLen > 0)
{
hash.CalculateDigest(Ai, buffer, buffer.size());
if (timeInSeconds)
{
timeInSeconds = timeInSeconds / ((derivedLen + Ai.size() - 1) / Ai.size());
timer.StartTimer();
}
for (i=1; i<iterations || (timeInSeconds && (i%128!=0 || timer.ElapsedTimeAsDouble() < timeInSeconds)); i++)
hash.CalculateDigest(Ai, Ai, Ai.size());
if (timeInSeconds)
{
iterations = (unsigned int)i;
timeInSeconds = 0;
}
for (i=0; i<B.size(); i++)
B[i] = Ai[i % Ai.size()];
Integer B1(B, B.size());
++B1;
for (i=0; i<ILen; i+=v)
(Integer(I+i, v) + B1).Encode(I+i, v);
size_t segmentLen = STDMIN(derivedLen, Ai.size());
memcpy(derived, Ai, segmentLen);
derived += segmentLen;
derivedLen -= segmentLen;
}
return iterations;
}
NAMESPACE_END
#endif
|
