Line data Source code
1 : /*
2 : This file is part of cpp-ethereum.
3 :
4 : cpp-ethereum is free software: you can redistribute it and/or modify
5 : it under the terms of the GNU General Public License as published by
6 : the Free Software Foundation, either version 3 of the License, or
7 : (at your option) any later version.
8 :
9 : cpp-ethereum is distributed in the hope that it will be useful,
10 : but WITHOUT ANY WARRANTY; without even the implied warranty of
11 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 : GNU General Public License for more details.
13 :
14 : You should have received a copy of the GNU General Public License
15 : along with cpp-ethereum. If not, see <http://www.gnu.org/licenses/>.
16 : */
17 : /** @file FixedHash.h
18 : * @author Gav Wood <i@gavwood.com>
19 : * @date 2014
20 : *
21 : * The FixedHash fixed-size "hash" container type.
22 : */
23 :
24 : #pragma once
25 :
26 : #include <array>
27 : #include <cstdint>
28 : #include <algorithm>
29 : #include <random>
30 : #include <opendht/rng.h>
31 :
32 : #include "CommonData.h"
33 :
34 : namespace dev {
35 :
36 : /// Compile-time calculation of Log2 of constant values.
37 : template<unsigned N>
38 : struct StaticLog2
39 : {
40 : enum { result = 1 + StaticLog2<N / 2>::result };
41 : };
42 : template<>
43 : struct StaticLog2<1>
44 : {
45 : enum { result = 0 };
46 : };
47 :
48 : /// Fixed-size raw-byte array container type, with an API optimised for storing hashes.
49 : /// Transparently converts to/from the corresponding arithmetic type; this will
50 : /// assume the data contained in the hash is big-endian.
51 : template<unsigned N>
52 : class FixedHash
53 : {
54 : public:
55 : /// The size of the container.
56 : enum { size = N };
57 :
58 : /// A dummy flag to avoid accidental construction from pointer.
59 : enum ConstructFromPointerType { ConstructFromPointer };
60 :
61 : /// Method to convert from a string.
62 : enum ConstructFromStringType { FromHex, FromBinary };
63 :
64 : /// Method to convert from a string.
65 : enum ConstructFromHashType { AlignLeft, AlignRight, FailIfDifferent };
66 :
67 : /// Construct an empty hash.
68 5284 : FixedHash() { m_data.fill(0); }
69 :
70 : /// Construct from another hash, filling with zeroes or cropping as necessary.
71 : template<unsigned M>
72 : explicit FixedHash(FixedHash<M> const& _h, ConstructFromHashType _t = AlignLeft)
73 : {
74 : m_data.fill(0);
75 : unsigned c = std::min(M, N);
76 : for (unsigned i = 0; i < c; ++i)
77 : m_data[_t == AlignRight ? N - 1 - i : i] = _h[_t == AlignRight ? M - 1 - i : i];
78 : }
79 :
80 : /// Convert from unsigned
81 : explicit FixedHash(unsigned _u) { toBigEndian(_u, m_data); }
82 :
83 : /// Explicitly construct, copying from a byte array.
84 776 : explicit FixedHash(bytes const& _b, ConstructFromHashType _t = FailIfDifferent)
85 : {
86 776 : if (_b.size() == N)
87 1552 : memcpy(m_data.data(), _b.data(), std::min<unsigned>(_b.size(), N));
88 : else {
89 0 : m_data.fill(0);
90 0 : if (_t != FailIfDifferent) {
91 0 : auto c = std::min<unsigned>(_b.size(), N);
92 0 : for (unsigned i = 0; i < c; ++i)
93 0 : m_data[_t == AlignRight ? N - 1 - i : i] = _b[_t == AlignRight ? _b.size() - 1 - i : i];
94 : }
95 : }
96 776 : }
97 :
98 : /// Explicitly construct, copying from a byte array.
99 : explicit FixedHash(bytesConstRef _b, ConstructFromHashType _t = FailIfDifferent)
100 : {
101 : if (_b.size() == N)
102 : memcpy(m_data.data(), _b.data(), std::min<unsigned>(_b.size(), N));
103 : else {
104 : m_data.fill(0);
105 : if (_t != FailIfDifferent) {
106 : auto c = std::min<unsigned>(_b.size(), N);
107 : for (unsigned i = 0; i < c; ++i)
108 : m_data[_t == AlignRight ? N - 1 - i : i] = _b[_t == AlignRight ? _b.size() - 1 - i : i];
109 : }
110 : }
111 : }
112 :
113 : /// Explicitly construct, copying from a bytes in memory with given pointer.
114 1505 : explicit FixedHash(uint8_t const* _bs, ConstructFromPointerType) { memcpy(m_data.data(), _bs, N); }
115 :
116 : /// Explicitly construct, copying from a string.
117 0 : explicit FixedHash(std::string const& _s,
118 : ConstructFromStringType _t = FromHex,
119 : ConstructFromHashType _ht = FailIfDifferent)
120 0 : : FixedHash(_t == FromHex ? fromHex(_s, WhenError::Throw) : dev::asBytes(_s), _ht)
121 0 : {}
122 :
123 : /// @returns true iff this is the empty hash.
124 2234 : explicit operator bool() const
125 : {
126 4478 : return std::any_of(m_data.begin(), m_data.end(), [](uint8_t _b) { return _b != 0; });
127 : }
128 :
129 : // The obvious comparison operators.
130 : bool operator==(FixedHash const& _c) const { return m_data == _c.m_data; }
131 : bool operator!=(FixedHash const& _c) const { return m_data != _c.m_data; }
132 0 : bool operator<(FixedHash const& _c) const
133 : {
134 0 : for (unsigned i = 0; i < N; ++i)
135 0 : if (m_data[i] < _c.m_data[i])
136 0 : return true;
137 0 : else if (m_data[i] > _c.m_data[i])
138 0 : return false;
139 0 : return false;
140 : }
141 : bool operator>=(FixedHash const& _c) const { return !operator<(_c); }
142 0 : bool operator<=(FixedHash const& _c) const { return operator==(_c) || operator<(_c); }
143 0 : bool operator>(FixedHash const& _c) const { return !operator<=(_c); }
144 :
145 : // The obvious binary operators.
146 : FixedHash& operator^=(FixedHash const& _c)
147 : {
148 : for (unsigned i = 0; i < N; ++i)
149 : m_data[i] ^= _c.m_data[i];
150 : return *this;
151 : }
152 : FixedHash operator^(FixedHash const& _c) const { return FixedHash(*this) ^= _c; }
153 : FixedHash& operator|=(FixedHash const& _c)
154 : {
155 : for (unsigned i = 0; i < N; ++i)
156 : m_data[i] |= _c.m_data[i];
157 : return *this;
158 : }
159 : FixedHash operator|(FixedHash const& _c) const { return FixedHash(*this) |= _c; }
160 : FixedHash& operator&=(FixedHash const& _c)
161 : {
162 : for (unsigned i = 0; i < N; ++i)
163 : m_data[i] &= _c.m_data[i];
164 : return *this;
165 : }
166 : FixedHash operator&(FixedHash const& _c) const { return FixedHash(*this) &= _c; }
167 : FixedHash operator~() const
168 : {
169 : FixedHash ret;
170 : for (unsigned i = 0; i < N; ++i)
171 : ret[i] = ~m_data[i];
172 : return ret;
173 : }
174 :
175 : // Big-endian increment.
176 : FixedHash& operator++()
177 : {
178 : for (unsigned i = size; i > 0 && !++m_data[--i];) {
179 : }
180 : return *this;
181 : }
182 :
183 : /// @returns true if all one-bits in @a _c are set in this object.
184 : bool contains(FixedHash const& _c) const { return (*this & _c) == _c; }
185 :
186 : /// @returns a particular byte from the hash.
187 : uint8_t& operator[](unsigned _i) { return m_data[_i]; }
188 : /// @returns a particular byte from the hash.
189 : uint8_t operator[](unsigned _i) const { return m_data[_i]; }
190 :
191 : /// @returns an abridged version of the hash as a user-readable hex string.
192 : std::string abridged() const { return toHex(ref().cropped(0, 4)) + "\342\200\246"; }
193 :
194 : /// @returns a version of the hash as a user-readable hex string that leaves out the middle part.
195 : std::string abridgedMiddle() const
196 : {
197 : return toHex(ref().cropped(0, 4)) + "\342\200\246" + toHex(ref().cropped(N - 4));
198 : }
199 :
200 : /// @returns the hash as a user-readable hex string.
201 776 : std::string hex() const { return toHex(ref()); }
202 :
203 : /// @returns a mutable byte vector_ref to the object's data.
204 3090 : bytesRef ref() { return bytesRef(m_data.data(), N); }
205 :
206 : /// @returns a constant byte vector_ref to the object's data.
207 6020 : bytesConstRef ref() const { return bytesConstRef(m_data.data(), N); }
208 :
209 : /// @returns a mutable byte pointer to the object's data.
210 3010 : uint8_t* data() { return m_data.data(); }
211 :
212 : /// @returns a constant byte pointer to the object's data.
213 4468 : uint8_t const* data() const { return m_data.data(); }
214 :
215 : /// @returns begin iterator.
216 : auto begin() const -> typename std::array<uint8_t, N>::const_iterator { return m_data.begin(); }
217 :
218 : /// @returns end iterator.
219 : auto end() const -> typename std::array<uint8_t, N>::const_iterator { return m_data.end(); }
220 :
221 : /// @returns a copy of the object's data as a byte vector.
222 2187 : bytes asBytes() const { return bytes(data(), data() + N); }
223 :
224 : /// @returns a mutable reference to the object's data as an STL array.
225 : std::array<uint8_t, N>& asArray() { return m_data; }
226 :
227 : /// @returns a constant reference to the object's data as an STL array.
228 : std::array<uint8_t, N> const& asArray() const { return m_data; }
229 :
230 : /// Populate with random data.
231 : template<class Engine>
232 729 : void randomize(Engine& _eng)
233 : {
234 24057 : for (auto& i : m_data)
235 23328 : i = (uint8_t) std::uniform_int_distribution<uint16_t>(0, 255)(_eng);
236 729 : }
237 :
238 : /// @returns a random valued object.
239 : static FixedHash random()
240 : {
241 : FixedHash ret;
242 : std::random_device rd;
243 : ret.randomize(rd);
244 : return ret;
245 : }
246 :
247 : template<unsigned P, unsigned M>
248 : inline FixedHash& shiftBloom(FixedHash<M> const& _h)
249 : {
250 : return (*this |= _h.template bloomPart<P, N>());
251 : }
252 :
253 : template<unsigned P, unsigned M>
254 : inline bool containsBloom(FixedHash<M> const& _h)
255 : {
256 : return contains(_h.template bloomPart<P, N>());
257 : }
258 :
259 : template<unsigned P, unsigned M>
260 : inline FixedHash<M> bloomPart() const
261 : {
262 : unsigned const c_bloomBits = M * 8;
263 : unsigned const c_mask = c_bloomBits - 1;
264 : unsigned const c_bloomBytes = (StaticLog2<c_bloomBits>::result + 7) / 8;
265 :
266 : static_assert((M & (M - 1)) == 0, "M must be power-of-two");
267 : static_assert(P * c_bloomBytes <= N, "out of range");
268 :
269 : FixedHash<M> ret;
270 : uint8_t const* p = data();
271 : for (unsigned i = 0; i < P; ++i) {
272 : unsigned index = 0;
273 : for (unsigned j = 0; j < c_bloomBytes; ++j, ++p)
274 : index = (index << 8) | *p;
275 : index &= c_mask;
276 : ret[M - 1 - index / 8] |= (1 << (index % 8));
277 : }
278 : return ret;
279 : }
280 :
281 : /// Returns the index of the first bit set to one, or size() * 8 if no bits are set.
282 : inline unsigned firstBitSet() const
283 : {
284 : unsigned ret = 0;
285 : for (auto d : m_data)
286 : if (d)
287 : for (;; ++ret, d <<= 1)
288 : if (d & 0x80)
289 : return ret;
290 : else {
291 : }
292 : else
293 : ret += 8;
294 : return ret;
295 : }
296 :
297 : void clear() { m_data.fill(0); }
298 :
299 : private:
300 : std::array<uint8_t, N> m_data; ///< The binary data.
301 : };
302 :
303 : template<unsigned T>
304 : class SecureFixedHash : private FixedHash<T>
305 : {
306 : public:
307 : using ConstructFromHashType = typename FixedHash<T>::ConstructFromHashType;
308 : using ConstructFromStringType = typename FixedHash<T>::ConstructFromStringType;
309 : using ConstructFromPointerType = typename FixedHash<T>::ConstructFromPointerType;
310 729 : SecureFixedHash() = default;
311 776 : explicit SecureFixedHash(bytes const& _b, ConstructFromHashType _t = FixedHash<T>::FailIfDifferent)
312 776 : : FixedHash<T>(_b, _t)
313 776 : {}
314 : explicit SecureFixedHash(bytesConstRef _b, ConstructFromHashType _t = FixedHash<T>::FailIfDifferent)
315 : : FixedHash<T>(_b, _t)
316 : {}
317 : template<unsigned M>
318 : explicit SecureFixedHash(FixedHash<M> const& _h, ConstructFromHashType _t = FixedHash<T>::AlignLeft)
319 : : FixedHash<T>(_h, _t)
320 : {}
321 2234 : SecureFixedHash(SecureFixedHash<T> const& _h)
322 2234 : : FixedHash<T>(_h.makeInsecure())
323 2234 : {}
324 : template<unsigned M>
325 : explicit SecureFixedHash(SecureFixedHash<M> const& _h, ConstructFromHashType _t = FixedHash<T>::AlignLeft)
326 : : FixedHash<T>(_h.makeInsecure(), _t)
327 : {}
328 : explicit SecureFixedHash(std::string const& _s,
329 : ConstructFromStringType _t = FixedHash<T>::FromHex,
330 : ConstructFromHashType _ht = FixedHash<T>::FailIfDifferent)
331 : : FixedHash<T>(_s, _t, _ht)
332 : {}
333 : explicit SecureFixedHash(bytes const* _d, ConstructFromPointerType _t)
334 : : FixedHash<T>(_d, _t)
335 : {}
336 3739 : ~SecureFixedHash() { ref().cleanse(); }
337 :
338 : SecureFixedHash<T>& operator=(SecureFixedHash<T> const& _c)
339 : {
340 : if (&_c == this)
341 : return *this;
342 : ref().cleanse();
343 : FixedHash<T>::operator=(static_cast<FixedHash<T> const&>(_c));
344 : return *this;
345 : }
346 :
347 : using FixedHash<T>::size;
348 :
349 2963 : FixedHash<T> const& makeInsecure() const { return static_cast<FixedHash<T> const&>(*this); }
350 : FixedHash<T>& writable()
351 : {
352 : clear();
353 : return static_cast<FixedHash<T>&>(*this);
354 : }
355 :
356 : using FixedHash<T>::operator bool;
357 :
358 : // The obvious comparison operators.
359 : bool operator==(SecureFixedHash const& _c) const
360 : {
361 : return static_cast<FixedHash<T> const&>(*this).operator==(static_cast<FixedHash<T> const&>(_c));
362 : }
363 : bool operator!=(SecureFixedHash const& _c) const
364 : {
365 : return static_cast<FixedHash<T> const&>(*this).operator!=(static_cast<FixedHash<T> const&>(_c));
366 : }
367 : bool operator<(SecureFixedHash const& _c) const
368 : {
369 : return static_cast<FixedHash<T> const&>(*this).operator<(static_cast<FixedHash<T> const&>(_c));
370 : }
371 : bool operator>=(SecureFixedHash const& _c) const
372 : {
373 : return static_cast<FixedHash<T> const&>(*this).operator>=(static_cast<FixedHash<T> const&>(_c));
374 : }
375 : bool operator<=(SecureFixedHash const& _c) const
376 : {
377 : return static_cast<FixedHash<T> const&>(*this).operator<=(static_cast<FixedHash<T> const&>(_c));
378 : }
379 : bool operator>(SecureFixedHash const& _c) const
380 : {
381 : return static_cast<FixedHash<T> const&>(*this).operator>(static_cast<FixedHash<T> const&>(_c));
382 : }
383 :
384 : using FixedHash<T>::operator==;
385 : using FixedHash<T>::operator!=;
386 : using FixedHash<T>::operator<;
387 : using FixedHash<T>::operator>=;
388 : using FixedHash<T>::operator<=;
389 : using FixedHash<T>::operator>;
390 :
391 : // The obvious binary operators.
392 : SecureFixedHash& operator^=(FixedHash<T> const& _c)
393 : {
394 : static_cast<FixedHash<T>&>(*this).operator^=(_c);
395 : return *this;
396 : }
397 : SecureFixedHash operator^(FixedHash<T> const& _c) const { return SecureFixedHash(*this) ^= _c; }
398 : SecureFixedHash& operator|=(FixedHash<T> const& _c)
399 : {
400 : static_cast<FixedHash<T>&>(*this).operator^=(_c);
401 : return *this;
402 : }
403 : SecureFixedHash operator|(FixedHash<T> const& _c) const { return SecureFixedHash(*this) |= _c; }
404 : SecureFixedHash& operator&=(FixedHash<T> const& _c)
405 : {
406 : static_cast<FixedHash<T>&>(*this).operator^=(_c);
407 : return *this;
408 : }
409 : SecureFixedHash operator&(FixedHash<T> const& _c) const { return SecureFixedHash(*this) &= _c; }
410 :
411 : SecureFixedHash& operator^=(SecureFixedHash const& _c)
412 : {
413 : static_cast<FixedHash<T>&>(*this).operator^=(static_cast<FixedHash<T> const&>(_c));
414 : return *this;
415 : }
416 : SecureFixedHash operator^(SecureFixedHash const& _c) const { return SecureFixedHash(*this) ^= _c; }
417 : SecureFixedHash& operator|=(SecureFixedHash const& _c)
418 : {
419 : static_cast<FixedHash<T>&>(*this).operator^=(static_cast<FixedHash<T> const&>(_c));
420 : return *this;
421 : }
422 : SecureFixedHash operator|(SecureFixedHash const& _c) const { return SecureFixedHash(*this) |= _c; }
423 : SecureFixedHash& operator&=(SecureFixedHash const& _c)
424 : {
425 : static_cast<FixedHash<T>&>(*this).operator^=(static_cast<FixedHash<T> const&>(_c));
426 : return *this;
427 : }
428 : SecureFixedHash operator&(SecureFixedHash const& _c) const { return SecureFixedHash(*this) &= _c; }
429 : SecureFixedHash operator~() const
430 : {
431 : auto r = ~static_cast<FixedHash<T> const&>(*this);
432 : return static_cast<SecureFixedHash const&>(r);
433 : }
434 :
435 : using FixedHash<T>::abridged;
436 : using FixedHash<T>::abridgedMiddle;
437 :
438 3739 : bytesConstRef ref() const { return FixedHash<T>::ref(); }
439 1505 : uint8_t const* data() const { return FixedHash<T>::data(); }
440 :
441 729 : static SecureFixedHash<T> random()
442 : {
443 729 : SecureFixedHash<T> ret;
444 729 : std::random_device rd;
445 729 : ret.randomize(rd);
446 1458 : return ret;
447 729 : }
448 : using FixedHash<T>::firstBitSet;
449 :
450 : void clear() { ref().cleanse(); }
451 : };
452 :
453 : /// Fast equality operator for h256.
454 : template<>
455 : inline bool
456 0 : FixedHash<32>::operator==(FixedHash<32> const& _other) const
457 : {
458 0 : const uint64_t* hash1 = (const uint64_t*) data();
459 0 : const uint64_t* hash2 = (const uint64_t*) _other.data();
460 0 : return (hash1[0] == hash2[0]) && (hash1[1] == hash2[1]) && (hash1[2] == hash2[2]) && (hash1[3] == hash2[3]);
461 : }
462 :
463 : // Common types of FixedHash.
464 : using h2048 = FixedHash<256>;
465 : using h1024 = FixedHash<128>;
466 : using h520 = FixedHash<65>;
467 : using h512 = FixedHash<64>;
468 : using h256 = FixedHash<32>;
469 : using h160 = FixedHash<20>;
470 : using h128 = FixedHash<16>;
471 : using h64 = FixedHash<8>;
472 : using h512s = std::vector<h512>;
473 : using h256s = std::vector<h256>;
474 : using h160s = std::vector<h160>;
475 : using h256Set = std::set<h256>;
476 : using h160Set = std::set<h160>;
477 : using h256Hash = std::unordered_set<h256>;
478 : using h160Hash = std::unordered_set<h160>;
479 :
480 : /// Convert the given value into h160 (160-bit unsigned integer) using the right 20 bytes.
481 : inline h160
482 1505 : right160(h256 const& _t)
483 : {
484 1505 : h160 ret;
485 1505 : memcpy(ret.data(), _t.data() + 12, 20);
486 1505 : return ret;
487 : }
488 :
489 : } // namespace dev
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