Crypto++ 8.0 Free C++ class library of cryptographic schemes

scrypt.cpp
1 // scrypt.cpp - written and placed in public domain by Jeffrey Walton.
2 // Based on reference source code by Colin Percival for
3 // Scrypt and Daniel Bernstein for Salsa20 core.
4
5 #include "pch.h"
6
7 #include "scrypt.h"
8 #include "algparam.h"
9 #include "argnames.h"
10 #include "pwdbased.h"
11 #include "stdcpp.h"
12 #include "salsa.h"
13 #include "misc.h"
14 #include "sha.h"
15
16 #include <sstream>
17 #include <limits>
18
19 #ifdef _OPENMP
20 # include <omp.h>
21 #endif
22
23 // https://github.com/weidai11/cryptopp/issues/777
24 #if CRYPTOPP_GCC_DIAGNOSTIC_AVAILABLE
25 # if defined(__clang__)
26 # pragma GCC diagnostic ignored "-Wtautological-compare"
27 # elif defined(__GNUC__)
28 # pragma GCC diagnostic ignored "-Wtype-limits"
29 # endif
30 #endif
31
32 ANONYMOUS_NAMESPACE_BEGIN
33
34 using CryptoPP::byte;
35 using CryptoPP::word32;
36 using CryptoPP::word64;
37 using CryptoPP::GetWord;
38 using CryptoPP::PutWord;
39 using CryptoPP::Salsa20_Core;
40 using CryptoPP::rotlConstant;
41 using CryptoPP::LITTLE_ENDIAN_ORDER;
42 using CryptoPP::AlignedSecByteBlock;
43
44 inline void LE32ENC(byte* out, word32 in)
45 {
46 PutWord(false, LITTLE_ENDIAN_ORDER, out, in);
47 }
48
49 inline word32 LE32DEC(const byte* in)
50 {
51 return GetWord<word32>(false, LITTLE_ENDIAN_ORDER, in);
52 }
53
54 inline word64 LE64DEC(const byte* in)
55 {
56 return GetWord<word64>(false, LITTLE_ENDIAN_ORDER, in);
57 }
58
59 inline void BlockCopy(byte* dest, byte* src, size_t len)
60 {
61 // OpenMP 4.0 released July 2013.
62 #if _OPENMP >= 201307
63 #pragma omp simd
64 for (size_t i = 0; i < len; ++i)
65 dest[i] = src[i];
66 #else
67 for (size_t i = 0; i < len; ++i)
68 dest[i] = src[i];
69 #endif
70 }
71
72 inline void BlockXOR(byte* dest, byte* src, size_t len)
73 {
74 // OpenMP 4.0 released July 2013.
75 #if _OPENMP >= 201307
76 #pragma omp simd
77 for (size_t i = 0; i < len; ++i)
78 dest[i] ^= src[i];
79 #else
80 for (size_t i = 0; i < len; ++i)
81 dest[i] ^= src[i];
82 #endif
83 }
84
85 inline void PBKDF2_SHA256(byte* buf, size_t dkLen,
86 const byte* passwd, size_t passwdlen,
87 const byte* salt, size_t saltlen, byte count)
88 {
89 using CryptoPP::SHA256;
90 using CryptoPP::PKCS5_PBKDF2_HMAC;
91
92 PKCS5_PBKDF2_HMAC<SHA256> pbkdf;
93 pbkdf.DeriveKey(buf, dkLen, 0, passwd, passwdlen, salt, saltlen, count, 0.0f);
94 }
95
96 inline void Salsa20_8(byte B[64])
97 {
98 word32 B32[16];
99
100 for (size_t i = 0; i < 16; ++i)
101 B32[i] = LE32DEC(&B[i * 4]);
102
103 Salsa20_Core(B32, 8);
104
105 for (size_t i = 0; i < 16; ++i)
106 LE32ENC(&B[4 * i], B32[i]);
107 }
108
109 inline void BlockMix(byte* B, byte* Y, size_t r)
110 {
111 byte X[64];
112
113 // 1: X <-- B_{2r - 1}
114 BlockCopy(X, &B[(2 * r - 1) * 64], 64);
115
116 // 2: for i = 0 to 2r - 1 do
117 for (size_t i = 0; i < 2 * r; ++i)
118 {
119 // 3: X <-- H(X \xor B_i)
120 BlockXOR(X, &B[i * 64], 64);
121 Salsa20_8(X);
122
123 // 4: Y_i <-- X
124 BlockCopy(&Y[i * 64], X, 64);
125 }
126
127 // 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1})
128 for (size_t i = 0; i < r; ++i)
129 BlockCopy(&B[i * 64], &Y[(i * 2) * 64], 64);
130
131 for (size_t i = 0; i < r; ++i)
132 BlockCopy(&B[(i + r) * 64], &Y[(i * 2 + 1) * 64], 64);
133 }
134
135 inline word64 Integerify(byte* B, size_t r)
136 {
137 byte* X = &B[(2 * r - 1) * 64];
138 return LE64DEC(X);
139 }
140
141 inline void Smix(byte* B, size_t r, word64 N, byte* V, byte* XY)
142 {
143 byte* X = XY;
144 byte* Y = XY+128*r;
145
146 // 1: X <-- B
147 BlockCopy(X, B, 128 * r);
148
149 // 2: for i = 0 to N - 1 do
150 for (word64 i = 0; i < N; ++i)
151 {
152 // 3: V_i <-- X
153 BlockCopy(&V[i * (128 * r)], X, 128 * r);
154
155 // 4: X <-- H(X)
156 BlockMix(X, Y, r);
157 }
158
159 // 6: for i = 0 to N - 1 do
160 for (word64 i = 0; i < N; ++i)
161 {
162 // 7: j <-- Integerify(X) mod N
163 word64 j = Integerify(X, r) & (N - 1);
164
165 // 8: X <-- H(X \xor V_j)
166 BlockXOR(X, &V[j * (128 * r)], 128 * r);
167 BlockMix(X, Y, r);
168 }
169
170 // 10: B' <-- X
171 BlockCopy(B, X, 128 * r);
172 }
173
174 ANONYMOUS_NAMESPACE_END
175
176 NAMESPACE_BEGIN(CryptoPP)
177
178 size_t Scrypt::GetValidDerivedLength(size_t keylength) const
179 {
180 if (keylength > MaxDerivedLength())
181 return MaxDerivedLength();
182 return keylength;
183 }
184
185 void Scrypt::ValidateParameters(size_t derivedLen, word64 cost, word64 blockSize, word64 parallelization) const
186 {
187 // Optimizer should remove this on 32-bit platforms
188 if (std::numeric_limits<size_t>::max() > std::numeric_limits<word32>::max())
189 {
190 const word64 maxLen = ((static_cast<word64>(1) << 32) - 1) * 32;
191 if (derivedLen > maxLen) {
192 std::ostringstream oss;
193 oss << "derivedLen " << derivedLen << " is larger than " << maxLen;
194 throw InvalidArgument("Scrypt: " + oss.str());
195 }
196 }
197
198 // https://github.com/weidai11/cryptopp/issues/787
199 CRYPTOPP_ASSERT(parallelization <= std::numeric_limits<int>::max());
200 if (parallelization > static_cast<word64>(std::numeric_limits<int>::max()))
201 {
202 std::ostringstream oss;
203 oss << " parallelization " << parallelization << " is larger than ";
204 oss << std::numeric_limits<int>::max();
205 throw InvalidArgument("Scrypt: " + oss.str());
206 }
207
208 CRYPTOPP_ASSERT(IsPowerOf2(cost));
209 if (IsPowerOf2(cost) == false)
210 throw InvalidArgument("Scrypt: cost must be a power of 2");
211
212 const word64 prod = static_cast<word64>(blockSize) * parallelization;
213 CRYPTOPP_ASSERT(prod < (1U << 30));
214
215 if (prod >= (1U << 30)) {
216 std::ostringstream oss;
217 oss << "r*p " << prod << " is larger than " << (1U << 30);
218 throw InvalidArgument("Scrypt: " + oss.str());
219 }
220
221 // Scrypt has several tests that effectively verify allocations like
222 // '128 * r * N' and '128 * r * p' do not overflow. They are the tests
223 // that set errno to ENOMEM. We can make the logic a little more clear
224 // using word128. At first blush the word128 may seem like overkill.
225 // However, this alogirthm is dominated by slow moving parts, so a
226 // one-time check is insignificant in the bigger picture.
227 #if defined(CRYPTOPP_WORD128_AVAILABLE)
228 const word128 maxElems = static_cast<word128>(SIZE_MAX);
229 bool bLimit = (maxElems >= static_cast<word128>(cost) * blockSize * 128U);
230 bool xyLimit = (maxElems >= static_cast<word128>(parallelization) * blockSize * 128U);
231 bool vLimit = (maxElems >= static_cast<word128>(blockSize) * 256U + 64U);
232 #else
233 const word64 maxElems = static_cast<word64>(SIZE_MAX);
234 bool bLimit = (blockSize < maxElems / 128U / cost);
235 bool xyLimit = (blockSize < maxElems / 128U / parallelization);
236 bool vLimit = (blockSize < (maxElems - 64U) / 256U);
237 #endif
238
239 CRYPTOPP_ASSERT(bLimit); CRYPTOPP_ASSERT(xyLimit); CRYPTOPP_ASSERT(vLimit);
240 if (!bLimit || !xyLimit || !vLimit)
241 throw std::bad_alloc();
242 }
243
244 size_t Scrypt::DeriveKey(byte*derived, size_t derivedLen,
245 const byte*secret, size_t secretLen, const NameValuePairs& params) const
246 {
247 CRYPTOPP_ASSERT(secret /*&& secretLen*/);
248 CRYPTOPP_ASSERT(derived && derivedLen);
249 CRYPTOPP_ASSERT(derivedLen <= MaxDerivedLength());
250
251 word64 cost=0, blockSize=0, parallelization=0;
252 if(params.GetValue("Cost", cost) == false)
253 cost = defaultCost;
254
255 if(params.GetValue("BlockSize", blockSize) == false)
256 blockSize = defaultBlockSize;
257
258 if(params.GetValue("Parallelization", parallelization) == false)
259 parallelization = defaultParallelization;
260
261 ConstByteArrayParameter salt;
262 (void)params.GetValue("Salt", salt);
263
264 return DeriveKey(derived, derivedLen, secret, secretLen, salt.begin(), salt.size(), cost, blockSize, parallelization);
265 }
266
267 size_t Scrypt::DeriveKey(byte*derived, size_t derivedLen, const byte*secret, size_t secretLen,
268 const byte*salt, size_t saltLen, word64 cost, word64 blockSize, word64 parallel) const
269 {
270 CRYPTOPP_ASSERT(secret /*&& secretLen*/);
271 CRYPTOPP_ASSERT(derived && derivedLen);
272 CRYPTOPP_ASSERT(derivedLen <= MaxDerivedLength());
273
274 ThrowIfInvalidDerivedLength(derivedLen);
275 ValidateParameters(derivedLen, cost, blockSize, parallel);
276
277 AlignedSecByteBlock B(static_cast<size_t>(blockSize * parallel * 128U));
278
279 // 1: (B_0 ... B_{p-1}) <-- PBKDF2(P, S, 1, p * MFLen)
280 PBKDF2_SHA256(B, B.size(), secret, secretLen, salt, saltLen, 1);
281
282 // Visual Studio and OpenMP 2.0 fixup. We must use int, not size_t.
283 int maxParallel=0;
284 if (!SafeConvert(parallel, maxParallel))
285 maxParallel = std::numeric_limits<int>::max();
286
287 #ifdef _OPENMP
288 int threads = STDMIN(omp_get_max_threads(), maxParallel);
289 #endif
290
291 // http://stackoverflow.com/q/49604260/608639
292 #pragma omp parallel num_threads(threads)
293 {
294 // Each thread gets its own copy
295 AlignedSecByteBlock XY(static_cast<size_t>(blockSize * 256U));
296 AlignedSecByteBlock V(static_cast<size_t>(blockSize * cost * 128U));
297
298 // 2: for i = 0 to p - 1 do
299 #pragma omp for
300 for (int i = 0; i < maxParallel; ++i)
301 {
302 // 3: B_i <-- MF(B_i, N)
303 const ptrdiff_t offset = static_cast<ptrdiff_t>(blockSize*i*128);
304 Smix(B+offset, static_cast<size_t>(blockSize), cost, V, XY);
305 }
306 }
307
308 // 5: DK <-- PBKDF2(P, B, 1, dkLen)
309 PBKDF2_SHA256(derived, derivedLen, secret, secretLen, B, B.size(), 1);
310
311 return 1;
312 }
313
314 NAMESPACE_END
ConstByteArrayParameter
Used to pass byte array input as part of a NameValuePairs object.
Definition: algparam.h:20
argnames.h
Standard names for retrieving values by name when working with NameValuePairs.
InvalidArgument
An invalid argument was detected.
Definition: cryptlib.h:202
algparam.h
Classes for working with NameValuePairs.
SafeConvert
bool SafeConvert(T1 from, T2 &to)
Tests whether a conversion from -> to is safe to perform.
Definition: misc.h:590
misc.h
Utility functions for the Crypto++ library.
ConstByteArrayParameter::size
size_t size() const
Length of the memory block.
Definition: algparam.h:84
PutWord
void PutWord(bool assumeAligned, ByteOrder order, byte *block, T value, const byte *xorBlock=NULL)
Access a block of memory.
Definition: misc.h:2396
stdcpp.h
Common C++ header files.
Scrypt::MaxDerivedLength
size_t MaxDerivedLength() const
Determine maximum number of bytes.
Definition: scrypt.h:48
LITTLE_ENDIAN_ORDER
byte order is little-endian
Definition: cryptlib.h:145
PKCS5_PBKDF2_HMAC
PBKDF2 from PKCS #5.
Definition: pwdbased.h:149
PKCS5_PBKDF2_HMAC::DeriveKey
size_t DeriveKey(byte *derived, size_t derivedLen, const byte *secret, size_t secretLen, const NameValuePairs &params=g_nullNameValuePairs) const
Derive a key from a seed.
Definition: pwdbased.h:215
GetWord
T GetWord(bool assumeAligned, ByteOrder order, const byte *block)
Access a block of memory.
Definition: misc.h:2354
ConstByteArrayParameter::begin
const byte * begin() const
Pointer to the first byte in the memory block.
Definition: algparam.h:80
rotlConstant
T rotlConstant(T x)
Performs a left rotate.
Definition: misc.h:1467
Salsa20_Core
void Salsa20_Core(word32 *data, unsigned int rounds)
Salsa20 core transform.
Definition: salsa.cpp:39
pch.h
Precompiled header file.
IsPowerOf2
bool IsPowerOf2(const T &value)
Tests whether a value is a power of 2.
Definition: misc.h:889
AlignedSecByteBlock
SecBlock using AllocatorWithCleanup<byte, true> typedef.
Definition: secblock.h:1062
STDMIN
const T & STDMIN(const T &a, const T &b)
Replacement function for std::min.
Definition: misc.h:535
CRYPTOPP_ASSERT
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition: trap.h:69
scrypt.h
Classes for Scrypt from RFC 7914.
sha.h
Classes for SHA-1 and SHA-2 family of message digests.
salsa.h
Classes for Salsa and Salsa20 stream ciphers.
pwdbased.h
Password based key derivation functions.
Scrypt::DeriveKey
size_t DeriveKey(byte *derived, size_t derivedLen, const byte *secret, size_t secretLen, const NameValuePairs &params) const
Derive a key from a seed.
Definition: scrypt.cpp:244
CryptoPP
Crypto++ library namespace.
NameValuePairs::GetValue
bool GetValue(const char *name, T &value) const
Get a named value.
Definition: cryptlib.h:350
Scrypt
Scrypt key derivation function.
Definition: scrypt.h:33
SecBlock::size
size_type size() const
Provides the count of elements in the SecBlock.
Definition: secblock.h:797
SIZE_MAX
#define SIZE_MAX
The maximum value of a machine word.
Definition: misc.h:86
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:293