aboutsummaryrefslogblamecommitdiff
path: root/ecdsa_model_fpga.cpp
blob: 8ad09628e03c2ab1d34655c277d4cab33b2fb56b (plain) (tree)
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





























































































































































































































































































































































































































                                                                                                                                                        
//------------------------------------------------------------------------------
//
// ecdsa_model_fpga.cpp
// --------------------------------------------
// Base point scalar multiplier model for ECDSA
//
// Authors: Pavel Shatov
//
// Copyright (c) 2015-2016, NORDUnet A/S
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// - Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
//
// - Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
//
// - Neither the name of the NORDUnet nor the names of its contributors may be
//   used to endorse or promote products derived from this software without
//   specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
//------------------------------------------------------------------------------


//------------------------------------------------------------------------------
// Headers
//------------------------------------------------------------------------------
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include "ecdsa_model.h"
#include "fpga_lowlevel.h"
#include "fpga_modular.h"
#include "fpga_curve.h"
#include "fpga_util.h"


//------------------------------------------------------------------------------
// Prototypes
//------------------------------------------------------------------------------
void	fpga_model_init					();
bool	test_base_point_multiplier		(FPGA_BUFFER *k, FPGA_BUFFER *qx, FPGA_BUFFER *qy);

bool	abuse_internal_point_adder		();
bool	abuse_internal_point_doubler	();

void	print_fpga_buffer				(const char *s, FPGA_BUFFER *v);

bool	compare_fpga_buffers			(FPGA_BUFFER *ax, FPGA_BUFFER *ay, FPGA_BUFFER *bx, FPGA_BUFFER *by);
bool	compare_fpga_buffers			(FPGA_BUFFER *ax, FPGA_BUFFER *ay, FPGA_BUFFER *az, FPGA_BUFFER *bx, FPGA_BUFFER *by, FPGA_BUFFER *bz);


//------------------------------------------------------------------------------
// Locals
//------------------------------------------------------------------------------
static FPGA_BUFFER ecdsa_d;
static FPGA_BUFFER ecdsa_k;
static FPGA_BUFFER ecdsa_n;


//------------------------------------------------------------------------------
int main()
//------------------------------------------------------------------------------
{
	bool	ok;		// flag

		//
		// initialize buffers
		//
	fpga_model_init();
	fpga_modular_init();
	fpga_curve_init();

	
		//
		// test base point multiplier: Q = d * G
		//
	printf("Trying to derive public key from private key...\n\n");
	ok = test_base_point_multiplier(&ecdsa_d, &ecdsa_q_x, &ecdsa_q_y);
	if (!ok) return EXIT_FAILURE;


		//
		// test base point multiplier: R = k * G
		//
	printf("Trying to sign something...\n\n");
	ok = test_base_point_multiplier(&ecdsa_k, &ecdsa_r_x, &ecdsa_r_y);
	if (!ok) return EXIT_FAILURE;


		//
		// test base point multiplier: O = n * G
		//
	printf("Trying to multiply the base point by its order...\n\n");
	ok = test_base_point_multiplier(&ecdsa_n, &ecdsa_zero, &ecdsa_zero);
	if (!ok) return EXIT_FAILURE;


		//
		// try to abuse internal point doubler
		//
	ok = abuse_internal_point_doubler();
	if (!ok) return EXIT_FAILURE;
	

		//
		// try to abuse internal point adder
		//
	ok = abuse_internal_point_adder();
	if (!ok) return EXIT_FAILURE;
	

		//
		// everything went just fine
		//
	return EXIT_SUCCESS;
}


//------------------------------------------------------------------------------
void fpga_model_init()
//------------------------------------------------------------------------------
{
	int w;	// word counter

	FPGA_BUFFER tmp_d = ECDSA_D;
	FPGA_BUFFER tmp_k = ECDSA_K;
	FPGA_BUFFER tmp_n = ECDSA_N;

		/* fill buffers for large multi-word integers */
	for (w=0; w<OPERAND_NUM_WORDS; w++)
	{	ecdsa_d.words[w] = tmp_d.words[OPERAND_NUM_WORDS - (w+1)];
		ecdsa_k.words[w] = tmp_k.words[OPERAND_NUM_WORDS - (w+1)];
		ecdsa_n.words[w] = tmp_n.words[OPERAND_NUM_WORDS - (w+1)];
	}
}


//------------------------------------------------------------------------------
bool test_base_point_multiplier(FPGA_BUFFER *k, FPGA_BUFFER *qx, FPGA_BUFFER *qy)
//------------------------------------------------------------------------------
//
// k - multiplier
//
// qx, qy - expected coordinates of product
//
// Returns true when point (rx,ry) = k * G matches the point (qx,qy).
//
//------------------------------------------------------------------------------
{
	bool ok;				// flag
	FPGA_BUFFER rx, ry;		// result

		/* run the model */
	fpga_curve_scalar_multiply(k, &rx, &ry);

		/* handle result */
	ok = compare_fpga_buffers(qx, qy, &rx, &ry);
	if (!ok)
	{	printf("\n    ERROR\n\n");
		return false;
	}
	else printf("\n    OK\n\n");

		// everything went just fine
	return true;
}


//------------------------------------------------------------------------------
bool abuse_internal_point_doubler()
//------------------------------------------------------------------------------
//
// This routine tries to abuse the internal curve point doubler by forcing it
// to double point at infinity.
//
//------------------------------------------------------------------------------
{
	int w;		// word counter
	bool ok;	// flag
	
	FPGA_BUFFER px, py, pz;		// input
	FPGA_BUFFER qx, qy, qz;		// output

		// set P.X and P.Y to some "random" garbage and P.Z to zero
	for (w=0; w<OPERAND_NUM_WORDS; w++)
	{	px.words[w] = ecdsa_g_x.words[w] ^ ecdsa_h_x.words[w];
		py.words[w] = ecdsa_g_y.words[w] ^ ecdsa_h_y.words[w];
	}
	fpga_buffer_copy(&ecdsa_zero, &pz);

		// try to double point at infinity (should produce point at infinity)
	printf("Trying to double something at infinity...\n\n");
	fpga_curve_double_jacobian(&px, &py, &pz, &qx, &qy, &qz);

		// handle result
	ok = compare_fpga_buffers(&ecdsa_one, &ecdsa_one, &ecdsa_zero, &qx, &qy, &qz);
	if (! ok)
	{	printf("\n    ERROR\n\n");
		return false;
	}
	else printf("\n    OK\n\n");

		// everything went just fine
	return true;
}


//------------------------------------------------------------------------------
bool abuse_internal_point_adder()
//------------------------------------------------------------------------------
//
// This routine tries to abuse the internal curve point adder by forcing it to
// go throgh all the possible "corner cases".
//
//------------------------------------------------------------------------------
{
	int w;		// word counter	
	bool ok;	// flag

	FPGA_BUFFER px, py, pz;		// input
	FPGA_BUFFER rx, ry, rz;		// output

	//
	// try to add point at infinity to the base point
	//
	{
			// set P.X and P.Y to some "random" garbage and P.Z to zero
		for (w=0; w<OPERAND_NUM_WORDS; w++)
		{	px.words[w] = ecdsa_g_x.words[w] ^ ecdsa_h_x.words[w];
			py.words[w] = ecdsa_g_y.words[w] ^ ecdsa_h_y.words[w];
		}
		fpga_buffer_copy(&ecdsa_zero, &pz);

			// run addition proceduce
		printf("Trying to add something at infinity to the base point...\n\n");
		fpga_curve_add_jacobian(&px, &py, &pz, &rx, &ry, &rz);

			// handle result
		ok = compare_fpga_buffers(&ecdsa_g_x, &ecdsa_g_y, &ecdsa_one, &rx, &ry, &rz);
		if (! ok)
		{	printf("\n    ERROR\n\n");
			return false;
		}
		else printf("\n    OK\n\n");
	}

	//
	// try to add the base point to itself
	//
	{
			// set P to G
		fpga_buffer_copy(&ecdsa_g_x, &px);
		fpga_buffer_copy(&ecdsa_g_y, &py);
		fpga_buffer_copy(&ecdsa_one, &pz);

			// run addition proceduce
		printf("Trying to add the base point to itself...\n\n");
		fpga_curve_add_jacobian(&px, &py, &pz, &rx, &ry, &rz);

			// handle result
		ok = compare_fpga_buffers(&ecdsa_h_x, &ecdsa_h_y, &ecdsa_one, &rx, &ry, &rz);
		if (! ok)
		{	printf("\n    ERROR\n\n");
			return false;
		}
		else printf("\n    OK\n\n");
	}

	//
	// try to add the base point to its opposite
	//
	{
			// set P to (G.X, -G.Y, 1)
		fpga_buffer_copy(&ecdsa_zero, &px);
		fpga_buffer_copy(&ecdsa_zero, &py);
		fpga_buffer_copy(&ecdsa_one,  &pz);

		fpga_modular_add(&ecdsa_zero, &ecdsa_g_x, &px);
		fpga_modular_sub(&ecdsa_zero, &ecdsa_g_y, &py);

			// run addition proceduce
		printf("Trying to add the base point to its opposite...\n\n");
		fpga_curve_add_jacobian(&px, &py, &pz, &rx, &ry, &rz);

			// handle result
		ok = compare_fpga_buffers(&ecdsa_one, &ecdsa_one, &ecdsa_zero, &rx, &ry, &rz);
		if (! ok)
		{	printf("\n    ERROR\n\n");
			return false;
		}
		else printf("\n    OK\n\n");
	}

		// everything went just fine
	return true;
}


//------------------------------------------------------------------------------
void print_fpga_buffer(const char *s, FPGA_BUFFER *buf)
//------------------------------------------------------------------------------
//
// Pretty print large multi-word integer.
//
//------------------------------------------------------------------------------
{
	int w;	// word counter

		// print header
	printf("%s", s);

		// print all bytes
	for (w=OPERAND_NUM_WORDS; w>0; w--)
	{	
		printf("%08x", buf->words[w-1]);

			// insert space after every group of 4 bytes
		if (w > 1) printf(" ");
	}

		// print footer
	printf("\n");
}


//------------------------------------------------------------------------------
bool compare_fpga_buffers(FPGA_BUFFER *ax, FPGA_BUFFER *ay, FPGA_BUFFER *bx, FPGA_BUFFER *by)
//------------------------------------------------------------------------------
//
// Compare affine coordinates of two points and return true when they match.
//
//------------------------------------------------------------------------------
{
	int w;	// word counter

		// print all the values
	print_fpga_buffer("  Expected:   X = ", ax);
	print_fpga_buffer("  Calculated: X = ", bx);
	printf("\n");
	print_fpga_buffer("  Expected:   Y = ", ay);
	print_fpga_buffer("  Calculated: Y = ", by);

		// compare values
	for (w=0; w<OPERAND_NUM_WORDS; w++)
	{
			// compare x
		if (ax->words[w] != bx->words[w]) return false;

			// compare y
		if (ay->words[w] != by->words[w]) return false;
	}

		// values are the same
	return true;
}


//------------------------------------------------------------------------------
bool compare_fpga_buffers(FPGA_BUFFER *ax, FPGA_BUFFER *ay, FPGA_BUFFER *az, FPGA_BUFFER *bx, FPGA_BUFFER *by, FPGA_BUFFER *bz)
//------------------------------------------------------------------------------
//
// Compare projective coordinates of two points and return true when they match.
//
//------------------------------------------------------------------------------
{
	int w;	// word counter

		// print all the values
	print_fpga_buffer("  Expected:   X = ", ax);
	print_fpga_buffer("  Calculated: X = ", bx);
	printf("\n");
	print_fpga_buffer("  Expected:   Y = ", ay);
	print_fpga_buffer("  Calculated: Y = ", by);
	printf("\n");
	print_fpga_buffer("  Expected:   Z = ", az);
	print_fpga_buffer("  Calculated: Z = ", bz);

		// compare values
	for (w=0; w<OPERAND_NUM_WORDS; w++)
	{
			// compare x
		if (ax->words[w] != bx->words[w]) return false;

			// compare y
		if (ay->words[w] != by->words[w]) return false;

			// compare z
		if (az->words[w] != bz->words[w]) return false;
	}

		// values are the same
	return true;
}


//------------------------------------------------------------------------------
// End-of-File
//------------------------------------------------------------------------------