-
Notifications
You must be signed in to change notification settings - Fork 1
/
percyclient_impl.h
1208 lines (1065 loc) · 44.2 KB
/
percyclient_impl.h
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
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// Percy++ Copyright 2007,2012,2013 Ian Goldberg <iang@cs.uwaterloo.ca>,
// Casey Devet <cjdevet@cs.uwaterloo.ca>,
// Paul Hendry <pshdenry@uwaterloo.ca>,
// Ryan Henry <rhenry@cs.uwaterloo.ca>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of version 2 of the GNU General Public License as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// There is a copy of the GNU General Public License in the COPYING file
// packaged with this plugin; if you cannot find it, write to the Free
// Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
// 02110-1301 USA
#ifndef __PERCYCLIENT_IMPL_H__
#define __PERCYCLIENT_IMPL_H__
#include <iostream>
#include <algorithm>
#include <deque>
#include "gf2e.h"
#include "pulse.h"
#include "percyparams.h"
#include "percyresult.h"
template <typename GF2E_Element>
inline void setCoeffs(GF2X &GF2X_P);
template <>
inline void setCoeffs<GF28_Element>(GF2X &GF2X_P) {
SetCoeff(GF2X_P, 8, 1);
SetCoeff(GF2X_P, 4, 1);
SetCoeff(GF2X_P, 3, 1);
SetCoeff(GF2X_P, 1, 1);
SetCoeff(GF2X_P, 0, 1);
}
template <>
inline void setCoeffs<GF216_Element>(GF2X &GF2X_P) {
SetCoeff(GF2X_P, 16, 1);
SetCoeff(GF2X_P, 14, 1);
SetCoeff(GF2X_P, 12, 1);
SetCoeff(GF2X_P, 7, 1);
SetCoeff(GF2X_P, 6, 1);
SetCoeff(GF2X_P, 4, 1);
SetCoeff(GF2X_P, 2, 1);
SetCoeff(GF2X_P, 1, 1);
SetCoeff(GF2X_P, 0, 1);
}
// Constructor and destructor
template <typename GF2E_Element>
PercyClient_GF2E<GF2E_Element>::PercyClient_GF2E (PercyClientParams ¶ms,
nservers_t num_servers, nservers_t t, sid_t * sids) :
PercyClient(params, num_servers, t),
indices(),
randmults(),
answers(),
unfinished_results(),
decoded()
{
// Initialize the GF2E modulus
GF2X MODULUS_P;
setCoeffs<GF2E_Element>(MODULUS_P);
GF2E::init(MODULUS_P);
GF2X::HexOutput = 1;
choose_indices(sids);
}
template <typename GF2E_Element>
PercyClient_GF2E<GF2E_Element>::PercyClient_GF2E (
const PercyClient_GF2E<GF2E_Element> &other) :
PercyClient(other),
indices(new GF2E_Element[num_servers]),
indices_ntl(other.indices_ntl),
answers(vector<GF2E_Element *>(other.answers.size())),
answers_ntl(other.answers_ntl),
unfinished_results(other.unfinished_results),
decoded(other.decoded)
{
dbsize_t words_per_block = params.words_per_block();
memcpy(indices, other.indices, num_servers * sizeof(GF2E_Element));
for (nqueries_t q = 0; q < answers.size(); ++q) {
answers[q] = new GF2E_Element[words_per_block * num_servers];
memcpy(answers[q], other.answers[q], words_per_block * num_servers *
sizeof(GF2E_Element));
}
}
template <typename GF2E_Element>
PercyClient_GF2E<GF2E_Element>& PercyClient_GF2E<GF2E_Element>::operator= (
PercyClient_GF2E<GF2E_Element> other)
{
PercyClient::operator=(other);
std::swap(indices, other.indices);
indices_ntl = other.indices_ntl;
randmults = other.randmults;
std::swap(answers, other.answers);
answers_ntl = other.answers_ntl;
unfinished_results = other.unfinished_results;
decoded = other.decoded;
return *this;
}
template <typename GF2E_Element>
PercyClient_GF2E<GF2E_Element>::~PercyClient_GF2E ()
{
if (indices != NULL) {
delete[] indices;
}
while (answers.size() > 0) {
if (answers.back() != NULL) {
delete[] answers.back();
}
answers.pop_back();
}
}
// Generate t-private (t+1)-of-l shares of a given secret value.
template <typename GF2E_Element>
static void genshares_GF2E(nservers_t t, nservers_t l,
const GF2E_Element *indices, GF2E_Element *values, GF2E_Element secret) {
// Pick a random polynomial of degree t with the right constant term
GF2E_Element * coeffs = new GF2E_Element[t+1];
coeffs[0] = secret;
for (nservers_t i=1;i<=t;++i) {
coeffs[i] = RandomBits_ulong(8*sizeof(GF2E_Element));
}
// Evaluate the polynomial at each of the indices
for (nservers_t i=0; i<l; ++i) {
values[i] = evalpoly_GF2E<GF2E_Element>(coeffs, t, indices[i]);
}
delete[] coeffs;
}
// Swap the query polynomials of unsynchronized files (this actually just zeroes out the appropriate entries)
template <typename GF2E_Element>
static void swap_symbols(nservers_t t, nservers_t num_servers, GF2E_Element *values,
dbsize_t num_blocks, const std::vector<dbsize_t> &sync_error_locs) {
for (std::vector<dbsize_t>::const_iterator it = sync_error_locs.begin(); it != sync_error_locs.end(); ++it) {
bool zeroed = true;
dbsize_t sync_idx = *it;
for (nservers_t j = 0; j < num_servers; j++) {
// check if the appropriate values of values is nonzero
if (values[(sync_idx * num_servers) + j] != 0) {
zeroed = false;
break;
}
}
// if the unsynchronized file will be touched by a server, swap its bits with zeros elsewhere
if (!zeroed) {
for (nservers_t j = 0; j < num_servers; j++) {
// // find zeros elsewhere in the vector
// dbsize_t swap_idx = sync_idx;
//For now, we are just zeroing out the offending entries instead of swapping them!
values[(sync_idx * num_servers) + j] = 0;
// // how do you check for equality ?
// while (swap_idx == sync_idx) {
// // pick a random new index in the range [0,num_blocks-1]
// dbsize_t rand_idx = RandomBits_ulong(8*sizeof(dbsize_t));
// // make sure the randomly drawn index is in range and not mis-synchronized
// if ((rand_idx >= num_blocks) ||
// (std::find(sync_error_locs.begin(), sync_error_locs.end(), rand_idx) == sync_error_locs.end())){
// continue;
// }
// // otherwise, swap the appropriate entries
// swap_idx = rand_idx;
// // std::swap(values[(num_blocks + sync_idx) * num_servers + j], values[(num_blocks + swap_idx) * num_servers + j]);
// }
}
}
}
// Sanity check
// for (std::vector<dbsize_t>::const_iterator it = sync_error_locs.begin(); it != sync_error_locs.end(); ++it) {
// dbsize_t sync_idx = *it;
// for (nservers_t j = 0; j < num_servers; j++) {
// std::cerr << "Printing mis-synched random values: " << values[(num_blocks + sync_idx) * num_servers + j] << std::endl;
// }
// }
}
/* GF:This method seems to choose which indices X we want to evaluate the polynomials at.
I.e. if the query is a random polynomial q(X), we need to evaluate it at some random X. */
template <typename GF2E_Element>
void PercyClient_GF2E<GF2E_Element>::choose_indices(sid_t *sids) {
indices = new GF2E_Element[num_servers];
for (nservers_t j=0; j<num_servers; ++j) {
if (params.tau()) {
// Use the indices provided
indices[j] = (GF2E_Element)sids[j];
} else {
// Use random indices
GF2E_Element r;
bool ok = false;
do {
r = RandomLen_long(8*sizeof(GF2E_Element));
if (r != 0) {
ok = true;
for (nservers_t k=0;k<j;++k) {
if (indices[k] == r) {
ok = false;
}
}
}
} while (!ok);
indices[j] = r;
}
}
// Create NTL version
indices_ntl.SetLength(num_servers);
for (nservers_t ix=0; ix<num_servers; ++ix) {
conv(indices_ntl[ix],
GF2XFromBytes((unsigned char *)(indices + ix), 1));
}
}
// Send a request for the given block number (0-based) to the
// servers connected with the ostreams in the given vector.
template <typename GF2E_Element>
int PercyClient_GF2E<GF2E_Element>::send_request(vector<dbsize_t> block_numbers,
std::vector<ostream*> &osvec)
{
nqueries_t num_queries = block_numbers.size();
if (num_servers != osvec.size()) {
std::cerr << "Incorrect iostream vector size passed to "
"send_request_GF2E.\n";
std::cerr << "Was " << osvec.size() << ", should be " << num_servers
<< ".\n";
return -1;
}
// Construct the vector of server indices
nqueries_t q;
// Generate random multiples (!= 0)
nqueries_t previous_queries = requested_blocks.size();
if (randomize) {
for (nqueries_t q = 0; q < num_queries; ++q) {
randmults.push_back(vector<GF2E_Element>());
vector<GF2E_Element>& query_randmults = randmults.back();
for (nservers_t j = 0; j < num_servers; ++j) {
GF2E_Element r = 0;
while (r == 0) {
r = RandomLen_long(8*sizeof(GF2E_Element));
}
query_randmults.push_back(r);
}
}
}
// Construct the shares of the e_{index} vector
dbsize_t num_blocks = params.num_blocks();
GF2E_Element * shares = new GF2E_Element[num_queries * num_blocks * num_servers];
for (q=0; q<num_queries; ++q) {
for (dbsize_t i = 0; i < num_blocks; ++i) {
genshares_GF2E<GF2E_Element>(t, num_servers, indices,
shares + (q * num_blocks + i) * num_servers, i == block_numbers[q]);
}
}
// Multiply shares by random multiples
if (randomize) {
for (nservers_t p = 0; p < num_servers; ++p) {
for (nqueries_t i = 0; i < num_queries; ++i) {
for (dbsize_t j = 0; j < num_blocks; ++j) {
dbsize_t index = (i * num_blocks + j) * num_servers + p;
shares[index] =
multiply_GF2E<GF2E_Element>(shares[index],
randmults[i+previous_queries][p]);
}
}
}
}
// Send the params and query to each server
for (nservers_t j = 0; j < num_servers; ++j) {
unsigned char nq[2];
nq[0] = (q >> 8) & 0xff;
nq[1] = (q) & 0xff;
osvec[j]->write((char *)nq, 2);
for (q=0; q<num_queries; ++q) {
for (dbsize_t i = 0; i < num_blocks; ++i) {
dbsize_t index = (q * num_blocks + i) * num_servers + j;
char *shareptr = (char *)&(shares[index]);
osvec[j]->write(shareptr, sizeof(GF2E_Element));
}
}
osvec[j]->flush();
}
// Add block numbers to requests_blocks
for (q = 0; q < num_queries; ++q) {
requested_blocks.push_back(block_numbers[q]);
}
delete[] shares;
return 0;
}
// Receive the server's replies, and return a number of servers that
// gave complete (but not necessarily correct) replies.
template <typename GF2E_Element>
nservers_t PercyClient_GF2E<GF2E_Element>::receive_replies (
std::vector<istream*> &isvec)
{
dbsize_t words_per_block = params.words_per_block();
nqueries_t num_queries = requested_blocks.size();
nqueries_t q;
// The vector of servers that have responded properly
goodservers.clear();
// The responses from the servers
nqueries_t previous_queries = received_blocks.size();
for (q = 0; q < num_queries; ++q) {
answers.push_back(new GF2E_Element[words_per_block * num_servers]);
}
nqueries_t total_queries = answers.size();
// Read the replies
for (nservers_t j = 0; j < num_servers; ++j) {
bool isgood = true;
for (q=previous_queries; q<total_queries; ++q) {
for (dbsize_t i = 0; isgood && i < words_per_block; ++i) {
isvec[j]->read((char *)(answers[q] + i * num_servers + j),
sizeof(GF2E_Element));
if (isvec[j]->eof()) {
std::cerr << "Server " << j+1 << " did not send complete reply.\n";
std::cerr << "Marking server " << j+1 << " as bad.\n";
isgood = false;
break;
}
if ((dbsize_t)(isvec[j]->gcount()) < 1) {
// Mark this server as bad
std::cerr << "Marking server " << j+1 << " as bad.\n";
isgood = false;
break;
}
}
}
if (isgood) {
goodservers.push_back(j);
}
}
// Add to unfinished_results and decoded
for (q=0; q<num_queries; ++q) {
unfinished_results.push_back(
vector<DecoderResult<GF2E> >(1, DecoderResult<GF2E>(goodservers, map<dbsize_t, GF2E>())));
decoded.push_back(std::set<dbsize_t>());
}
// Moved block numbers from requests_blocks to received_blocks
for (q = 0; q < num_queries; ++q) {
received_blocks.push_back(requested_blocks[q]);
}
requested_blocks.clear();
// Remove random multiple
if (randomize) {
for (nservers_t j = 0; j < num_servers; ++j) {
for (nqueries_t q = 0; q < num_queries; ++q) {
GF2E_Element randmult_inv =
inverse_GF2E<GF2E_Element>(randmults[q][j]);
for (dbsize_t i = 0; i < words_per_block; ++i) {
answers[q+previous_queries][i*num_servers + j] = multiply_GF2E<GF2E_Element>(
answers[q+previous_queries][i*num_servers + j], randmult_inv);
}
}
}
randmults.clear();
}
std::cerr << "Got replies...\n";
return goodservers.size();
}
// Construct the t+1 Lagrange coefficents to interpolate at the point
// alpha from the source points
// indices[goodservers[firstpoint .. firstpoint+numpoints-1]]
template <typename GF2E_Element>
void PercyClient_GF2E<GF2E_Element>::construct_lagrange_coeffs(GF2E_Element *coeffs,
GF2E_Element alpha, nservers_t firstpoint, nservers_t numpoints)
{
for (nservers_t i=0; i < numpoints; ++i) {
GF2E_Element numer = 1, denom = 1;
for (nservers_t j=0; j < numpoints; ++j) {
if (j==i) continue;
GF2E_Element numerdiff = indices[goodservers[firstpoint+j]] ^
alpha;
GF2E_Element denomdiff = indices[goodservers[firstpoint+j]] ^
indices[goodservers[firstpoint+i]];
numer = multiply_GF2E<GF2E_Element>(numer, numerdiff);
denom = multiply_GF2E<GF2E_Element>(denom, denomdiff);
}
coeffs[i] = multiply_GF2E<GF2E_Element>(numer,
inverse_GF2E<GF2E_Element>(denom));
}
}
// Do Lagrange interpolation of source values
// answers[goodservers[firstpoint..firstpoint+numpoints-1]] with the
// coefficients coeffs[0..t]
template <typename GF2E_Element>
inline GF2E_Element PercyClient_GF2E<GF2E_Element>::interpolate(
const GF2E_Element *word_answers, const GF2E_Element *coeffs,
nservers_t firstpoint, nservers_t numpoints)
{
GF2E_Element res = 0;
for (nservers_t i = 0; i < numpoints; ++i) {
res ^= multiply_GF2E<GF2E_Element>(coeffs[i],
word_answers[goodservers[firstpoint+i]]);
}
return res;
}
template <typename GF2E_Element>
bool PercyClient_GF2E<GF2E_Element>::try_fast_recover(nservers_t h,
vector<PercyBlockResults> &results)
{
dbsize_t words_per_block = params.words_per_block();
nqueries_t num_queries = answers.size();
nservers_t k = goodservers.size();
if (k <= t) return false;
// Construct the Lagrange coefficients for the target index 0, as
// well as for target indices[goodservers[0..(k-t-2)]] from the
// source indices[goodservers[k-t-1 .. k-1]]
// lagrange_coeffs[0] is the array of t+1 coeffs to interpolate 0
// largrnge_coeffs[a+1] is the array of t+1 coeffs to interpolate
// indices[goodservers[a]]
GF2E_Element * lagrange_coeffs = new GF2E_Element[(k-t) * (t+1)];
construct_lagrange_coeffs(lagrange_coeffs, 0, k-t-1, t+1);
for (nservers_t a = 0; a < k-t-1; ++a) {
construct_lagrange_coeffs(lagrange_coeffs + (a+1) * (t+1),
indices[goodservers[a]], k-t-1, t+1);
}
results.clear();
GF2E_Element *resblock = new GF2E_Element[words_per_block];
for (nqueries_t q = 0; q < num_queries; ++q) {
results.push_back(PercyBlockResults());
results.back().block_number = received_blocks[q];
for (dbsize_t word = 0; word < words_per_block; ++word) {
// Check if all the servers agree
bool match = true;
for (nservers_t a = 0; a < k-t-1; ++a) {
GF2E_Element expectedans =
answers[q][word*num_servers + goodservers[a]];
GF2E_Element actualans = interpolate(
answers[q] + word*num_servers, lagrange_coeffs + (a+1) * (t+1),
k-t-1, t+1);
if (expectedans != actualans) {
match = false;
break;
}
}
if (!match) {
delete[] lagrange_coeffs;
delete[] resblock;
results.clear();
return false;
}
resblock[word] = interpolate(answers[q] + word*num_servers,
lagrange_coeffs, k-t-1, t+1);
}
PercyResult thisresult(goodservers, string((char *)resblock,
words_per_block*sizeof(GF2E_Element)));
results.back().results.push_back(thisresult);
}
delete[] lagrange_coeffs;
delete[] resblock;
return true;
}
//Process the received replies and return the decoded results as a
//PercyResults object.
template <typename GF2E_Element>
nqueries_t PercyClient_GF2E<GF2E_Element>::process_replies (
nservers_t h, vector<PercyBlockResults> &results)
{
dbsize_t words_per_block = params.words_per_block();
nservers_t tau = params.tau();
// Check that results is empty
if (!(results.empty())) {
std::cerr << "The results vector must be empty\n";
return false;
}
std::cerr << goodservers.size() << " of " << num_servers << " servers responded.\n";
if (try_fast_recover(h, results)) {
// Clean up
received_blocks.clear();
while (answers.size() > 0) {
if (answers.back() != NULL) {
delete[] answers.back();
}
answers.pop_back();
}
answers_ntl.clear();
unfinished_results.clear();
decoded.clear();
return 0;
}
// Create NTL answers not yet created
for (nqueries_t q = answers_ntl.size(); q < received_blocks.size(); ++q) {
answers_ntl.push_back(vector<vec_GF2E>(words_per_block));
for (dbsize_t c = 0; c < words_per_block; ++c) {
answers_ntl[q][c].SetLength(num_servers);
for (nservers_t j = 0; j < num_servers; ++j) {
conv(answers_ntl[q][c][j],
GF2XFromBytes((unsigned char *)(answers[q] +
c * num_servers + j), sizeof(GF2E_Element)));
}
}
}
RSDecoder_GF2E decoder;
// Call the decoder's Recover method
bool res = decoder.Recover(sizeof(GF2E_Element), t+tau, h, goodservers,
answers_ntl, indices_ntl, unfinished_results, decoded);
// Convert the results to PercyBlockResults
// Remove queries that are completely decoded
for (nqueries_t q = 0; q < received_blocks.size(); ++q) {
results.push_back(PercyBlockResults());
results.back().block_number = received_blocks[q];
vector<PercyResult> &block_results = results.back().results;
if (decoded[q].size() == words_per_block) {
GF2E_Element *sigma = new GF2E_Element[words_per_block];
for (dbsize_t i = 0; i < unfinished_results[q].size(); ++i) {
for (dbsize_t j = 0; j < words_per_block; ++j) {
BytesFromGF2X((unsigned char *)(sigma + j),
rep(unfinished_results[q][i].recovered[j]),
sizeof(GF2E_Element));
}
block_results.push_back(PercyResult(unfinished_results[q][i].G,
string((char *)sigma, words_per_block * sizeof(GF2E_Element))));
}
delete[] sigma;
// Remove query
received_blocks.erase(received_blocks.begin() + q);
if (answers[q] != NULL) {
delete[] answers[q];
}
answers.erase(answers.begin() + q);
answers_ntl.erase(answers_ntl.begin() + q);
unfinished_results.erase(unfinished_results.begin() + q);
decoded.erase(decoded.begin() + q);
--q;
}
}
(void)res;
return received_blocks.size();
}
// Constructor and destructor
template <typename GF2E_Element>
PercyClient_RS_Sync<GF2E_Element>::PercyClient_RS_Sync (PercyClientParams ¶ms,
nservers_t num_servers, nservers_t t, sid_t * sids) :
PercyClient_GF2E<GF2E_Element>::PercyClient_GF2E(params, num_servers, t, sids),
sync_error_locs()
{ }
template <typename GF2E_Element>
PercyClient_RS_Sync<GF2E_Element>::PercyClient_RS_Sync (
const PercyClient_RS_Sync<GF2E_Element> &other) :
PercyClient_GF2E<GF2E_Element>::PercyClient_GF2E (&other),
sync_error_locs(other.sync_error_locs)
{}
template <typename GF2E_Element>
PercyClient_RS_Sync<GF2E_Element>& PercyClient_RS_Sync<GF2E_Element>::operator= (
PercyClient_RS_Sync<GF2E_Element> other)
{
PercyClient_GF2E<GF2E_Element>::operator=(other);
sync_error_locs = other.sync_error_locs;
return *this;
}
template <typename GF2E_Element>
PercyClient_RS_Sync<GF2E_Element>::~PercyClient_RS_Sync ()
{
PercyClient_GF2E<GF2E_Element>::~PercyClient_GF2E ();
}
template <typename GF2E_Element>
void PercyClient_RS_Sync<GF2E_Element>::choose_indices(sid_t *sids) {
PercyClient_GF2E<GF2E_Element>::choose_indices(sids);
}
// Send a request for the given block number (0-based) to the
// servers connected with the ostreams in the given vector.
template <typename GF2E_Element>
int PercyClient_RS_Sync<GF2E_Element>::send_request(vector<dbsize_t> block_numbers,
std::vector<ostream*> &osvec)
{
nqueries_t num_queries = block_numbers.size();
if (this->num_servers != osvec.size()) {
std::cerr << "Incorrect iostream vector size passed to "
"send_request_GF2E.\n";
std::cerr << "Was " << osvec.size() << ", should be " << this->num_servers
<< ".\n";
return -1;
}
// Construct the vector of server indices
nqueries_t q;
// Generate random multiples (!= 0)
nqueries_t previous_queries = this->requested_blocks.size();
if (this->randomize) {
for (nqueries_t q = 0; q < num_queries; ++q) {
this->randmults.push_back(vector<GF2E_Element>());
vector<GF2E_Element>& query_randmults = this->randmults.back();
for (nservers_t j = 0; j < this->num_servers; ++j) {
GF2E_Element r = 0;
while (r == 0) {
r = RandomLen_long(8*sizeof(GF2E_Element));
}
query_randmults.push_back(r);
}
}
}
// Construct the shares of the e_{index} vector
dbsize_t num_blocks = this->params.num_blocks();
GF2E_Element * shares = new GF2E_Element[num_queries * num_blocks * this->num_servers];
for (q=0; q<num_queries; ++q) {
for (dbsize_t i = 0; i < num_blocks; ++i) {
genshares_GF2E<GF2E_Element>(this->t, this->num_servers, this->indices,
shares + (q * num_blocks + i) * this->num_servers, i == block_numbers[q]);
}
}
swap_symbols<GF2E_Element>(this->t, this->num_servers, shares, num_blocks, this->sync_error_locs);
// Multiply shares by random multiples
if (this->randomize) {
for (nservers_t p = 0; p < this->num_servers; ++p) {
for (nqueries_t i = 0; i < num_queries; ++i) {
for (dbsize_t j = 0; j < num_blocks; ++j) {
dbsize_t index = (i * num_blocks + j) * this->num_servers + p;
shares[index] =
multiply_GF2E<GF2E_Element>(shares[index],
this->randmults[i+previous_queries][p]);
}
}
}
}
// Send the params and query to each server
for (nservers_t j = 0; j < this->num_servers; ++j) {
unsigned char nq[2]; //this stores the number of queries, and is read by the server
nq[0] = (q >> 8) & 0xff;
nq[1] = (q) & 0xff;
osvec[j]->write((char *)nq, 2);
for (q=0; q<num_queries; ++q) {
for (dbsize_t i = 0; i < num_blocks; ++i) {
dbsize_t index = (q * num_blocks + i) * this->num_servers + j;
char *shareptr = (char *)&(shares[index]);
osvec[j]->write(shareptr, sizeof(GF2E_Element));
}
}
osvec[j]->flush();
}
// Add block numbers to requests_blocks
for (q = 0; q < num_queries; ++q) {
this->requested_blocks.push_back(block_numbers[q]);
}
delete[] shares;
return 0;
}
// Send a request for the synchronization information to the
// servers connected with the ostreams in the given vector.
template <typename GF2E_Element>
int PercyClient_RS_Sync<GF2E_Element>::send_sync_request(std::vector<ostream*> &osvec)
{
if (this->num_servers != osvec.size()) {
std::cerr << "Incorrect iostream vector size passed to "
"send_request_GF2E.\n";
std::cerr << "Was " << osvec.size() << ", should be " << this->num_servers
<< ".\n";
return -1;
}
// Build the query polynomial ( q(X) = X^t + X^(t-1) + ... + X + 1 )
GF2E_Element * coeffs = new GF2E_Element[this->t+1];
coeffs[0] = 0;
for (nservers_t i=1;i<=this->t;++i) {
coeffs[i] = 1;
}
// Send the query to each server
for (nservers_t j = 0; j < this->num_servers; ++j) {
GF2E_Element q_x = evalpoly_GF2E<GF2E_Element>(coeffs, this->t, j+1);
unsigned char query[2]; //this stores the value of the query polynomial
query[0] = (q_x >> 8) & 0xff;
query[1] = (q_x & 0xff);
osvec[j]->write((char *)query, 2);
osvec[j]->flush();
}
delete[] coeffs;
return 0;
}
// Receive the server's replies, and return a number of servers that
// gave complete (but not necessarily correct) replies.
template <typename GF2E_Element>
nservers_t PercyClient_RS_Sync<GF2E_Element>::receive_replies (
std::vector<istream*> &isvec)
{
dbsize_t words_per_block = this->params.words_per_block();
nqueries_t num_queries = this->requested_blocks.size();
nqueries_t q;
// The vector of servers that have responded properly
this->goodservers.clear();
// The responses from the servers
nqueries_t previous_queries = this->received_blocks.size();
for (q = 0; q < num_queries; ++q) {
this->answers.push_back(new GF2E_Element[words_per_block * this->num_servers]);
}
nqueries_t total_queries = this->answers.size();
// Read the replies
for (nservers_t j = 0; j < this->num_servers; ++j) {
bool isgood = true;
for (q=previous_queries; q<total_queries; ++q) {
for (dbsize_t i = 0; isgood && i < words_per_block; ++i) {
isvec[j]->read((char *)(this->answers[q] + i * this->num_servers + j), sizeof(GF2E_Element));
if (isvec[j]->eof()) {
std::cerr << "Server " << j+1 << " did not send complete reply.\n";
std::cerr << "Marking server " << j+1 << " as bad (first).\n";
isgood = false;
break;
}
if ((dbsize_t)(isvec[j]->gcount()) < 1) {
// Mark this server as bad
std::cerr << "Marking server " << j+1 << " as bad (second).\n";
isgood = false;
break;
}
}
}
if (isgood) {
this->goodservers.push_back(j);
}
}
// Add to unfinished_results and decoded
for (q=0; q<num_queries; ++q) {
this->unfinished_results.push_back(
vector<DecoderResult<GF2E> >(1, DecoderResult<GF2E>(this->goodservers, map<dbsize_t, GF2E>())));
this->decoded.push_back(std::set<dbsize_t>());
}
// Moved block numbers from requests_blocks to received_blocks
for (q = 0; q < num_queries; ++q) {
this->received_blocks.push_back(this->requested_blocks[q]);
}
this->requested_blocks.clear();
// Remove random multiple
if (this->randomize) {
for (nservers_t j = 0; j < this->num_servers; ++j) {
for (nqueries_t q = 0; q < num_queries; ++q) {
GF2E_Element randmult_inv =
inverse_GF2E<GF2E_Element>(this->randmults[q][j]);
for (dbsize_t i = 0; i < words_per_block; ++i) {
this->answers[q+previous_queries][i*this->num_servers + j] = multiply_GF2E<GF2E_Element>(
this->answers[q+previous_queries][i*this->num_servers + j], randmult_inv);
}
}
}
this->randmults.clear();
}
std::cerr << "Got replies...\n";
return this->goodservers.size();
}
// Receive the server's replies to the sync request, return # of servers that
// gave complete (but not necessarily correct) replies.
template <typename GF2E_Element>
nservers_t PercyClient_RS_Sync<GF2E_Element>::receive_sync_replies (
std::vector<istream*> &isvec)
{
// The vector of servers that have responded properly
nservers_t res = 0;
// dbsize_t words_per_block = this->params.words_per_block();
// dbsize_t max_unsynchronized = this->params.max_unsynchronized();
dbsize_t num_bins = this->params.num_bins();
dbsize_t num_rows = num_bins * NUM_RATIOS;
// For each query, read the input vector, which is a sequence of
// num_blocks entries, each of length sizeof(GF2E_Element) bytes
// GF2E_Element *input = new GF2E_Element[words_per_block];
// std::vector<std::array<GF2E_Element,WORDS_PER_BLOCK> > input(num_rows);
std::vector<GF2E_Element*> replies;
for (dbsize_t i=0; i<this->num_servers; i++) {
replies.push_back(new GF2E_Element[num_rows*WORDS_PER_BLOCK]);
}
// Read in the output from the various servers!
for (nservers_t j = 0; j < this->num_servers; ++j) {
isvec[j]->read((char *) replies[j], num_rows * WORDS_PER_BLOCK * sizeof(GF2E_Element));
}
// Interpolate the results
std::vector<GF2E_Element*> compressed_results;
for (dbsize_t i=0; i<num_rows; i++) {
compressed_results.push_back(new GF2E_Element[WORDS_PER_BLOCK]);
}
interpolate_results(replies, this->num_servers, num_rows, compressed_results);
find_unsynchronized_files(this->num_servers, num_rows, compressed_results);
// Free the input memory
while (replies.size() > 0) {
if (replies.back() != NULL) {
delete[] replies.back();
}
replies.pop_back();
}
// Free the input memory
while (compressed_results.size() > 0) {
if (compressed_results.back() != NULL) {
delete[] compressed_results.back();
}
compressed_results.pop_back();
}
return res;
}
// Receive the server's replies to the sync request, return # of servers that
// gave complete (but not necessarily correct) replies.
template <typename GF2E_Element>
void PercyClient_RS_Sync<GF2E_Element>::interpolate_results (
std::vector<GF2E_Element*> &replies, nservers_t num_servers,
dbsize_t num_rows, std::vector<GF2E_Element*> &compressed_results)
{
dbsize_t result_len = num_rows * WORDS_PER_BLOCK;
GF2E_Element *outputvec = new GF2E_Element[result_len];
memset(outputvec, '\0', result_len*sizeof(GF2E_Element));
const GF216_Element *block;
for (dbsize_t j = 0; j < num_servers; ++j) {
GF216_Element inpv_j; // fill this in! should be [0 0 ... 1]*V^-1
switch(num_servers) {
case 3:
inpv_j = GF216_V_inv_3servers[j];
break;
case 4:
inpv_j = GF216_V_inv_4servers[j];
break;
case 5:
inpv_j = GF216_V_inv_5servers[j];
break;
default:
inpv_j = 1;
std::cout << "You need to work out the bottom row of V inverse for " << num_servers << " servers.\n";
}
if (inpv_j != 0) {
block = replies[j];
const GF216_Element *blockc = block;
GF216_Element log_j = GF216_log_table[inpv_j];
const GF216_Element *start = GF216_exp_table + log_j;
GF216_Element *oc = outputvec;
GF216_Element *oc_end = oc + (result_len & ~3);
GF216_Element block_c;
while(oc < oc_end) {
uint64_t accum = 0;
block_c = *(blockc++);
if (block_c != 0) {
GF216_Element log_c = GF216_log_table[block_c];
accum |= (uint64_t) start[log_c];
}
block_c = *(blockc++);
if (block_c != 0) {
GF216_Element log_c = GF216_log_table[block_c];
accum |= (uint64_t) start[log_c] << 16;
}
block_c = *(blockc++);
if (block_c != 0) {
GF216_Element log_c = GF216_log_table[block_c];
accum |= (uint64_t) start[log_c] << 32;
}
block_c = *(blockc++);
if (block_c != 0) {
GF216_Element log_c = GF216_log_table[block_c];
accum |= (uint64_t) start[log_c] << 48;
}
*((uint64_t *) oc) ^= accum;
oc+=4;
}
for (dbsize_t c = 0; c < (result_len & 3); ++c, ++oc) {
block_c = *(blockc++);
if (block_c != 0) {
GF216_Element log_c = GF216_log_table[block_c];
*oc ^= start[log_c];
}
}
}
}
for (dbsize_t i=0; i<num_rows; i++) {
std::copy(&outputvec[WORDS_PER_BLOCK*i],&outputvec[WORDS_PER_BLOCK*(i+1)-1],compressed_results[i]);
}
delete[] outputvec;
}
template <typename GF2E_Element>
int PercyClient_RS_Sync<GF2E_Element>::checkSingletonRatio(
const std::vector<GF2E_Element*> &compressed_results, dbsize_t i) {
int singleton_idx = -1;
bool singleton = true;
GF2E_Element ratio1, ratio2;
GF2E_Element previous_ratio = 1;
for (dbsize_t j=0; j<4; j++) {
ratio1 = multiply_GF2E<GF216_Element>(compressed_results[i+1][j],inverse_GF2E<GF216_Element>(compressed_results[i][j]));
ratio2 = multiply_GF2E<GF216_Element>(compressed_results[i+2][j],inverse_GF2E<GF216_Element>(compressed_results[i+1][j]));
if (i==2) {
// std::cerr << "The ratios are " << ratio1 << " and " << ratio2 <<std::endl;
// std::cerr << "The ratio1 stuff is " << compressed_results[i+1][j] << " and " << inverse_GF2E<GF216_Element>(compressed_results[i][j]) <<std::endl;
}
if (ratio1 != ratio2) {
singleton = false;
break;
}
if ((j>0) && (previous_ratio != ratio1)) {
singleton = false;
break;
}
previous_ratio = ratio1;
}
if (singleton && (previous_ratio != 0)) {
singleton_idx = GF216_log_table[previous_ratio];
}