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
|
/*
* Example ECDHE with Curve25519 program
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "mbedtls/build_info.h"
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_ECDH_C) || \
!defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) || \
!defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C)
int main( void )
{
mbedtls_printf( "MBEDTLS_ECDH_C and/or "
"MBEDTLS_ECP_DP_CURVE25519_ENABLED and/or "
"MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C "
"not defined\n" );
mbedtls_exit( 0 );
}
#else
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/ecdh.h"
#include <string.h>
int main( int argc, char *argv[] )
{
int ret = 1;
int exit_code = MBEDTLS_EXIT_FAILURE;
mbedtls_ecdh_context ctx_cli, ctx_srv;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
unsigned char cli_to_srv[36], srv_to_cli[33];
const char pers[] = "ecdh";
size_t srv_olen;
size_t cli_olen;
unsigned char secret_cli[32] = { 0 };
unsigned char secret_srv[32] = { 0 };
const unsigned char *p_cli_to_srv = cli_to_srv;
((void) argc);
((void) argv);
mbedtls_ecdh_init( &ctx_cli );
mbedtls_ecdh_init( &ctx_srv );
mbedtls_ctr_drbg_init( &ctr_drbg );
/*
* Initialize random number generation
*/
mbedtls_printf( " . Seed the random number generator..." );
fflush( stdout );
mbedtls_entropy_init( &entropy );
if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func,
&entropy,
(const unsigned char *) pers,
sizeof pers ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Client: initialize context and generate keypair
*/
mbedtls_printf( " . Set up client context, generate EC key pair..." );
fflush( stdout );
ret = mbedtls_ecdh_setup( &ctx_cli, MBEDTLS_ECP_DP_CURVE25519 );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_setup returned %d\n", ret );
goto exit;
}
ret = mbedtls_ecdh_make_params( &ctx_cli, &cli_olen, cli_to_srv,
sizeof( cli_to_srv ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_make_params returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Server: initialize context and generate keypair
*/
mbedtls_printf( " . Server: read params, generate public key..." );
fflush( stdout );
ret = mbedtls_ecdh_read_params( &ctx_srv, &p_cli_to_srv,
p_cli_to_srv + sizeof( cli_to_srv ) );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_read_params returned %d\n",
ret );
goto exit;
}
ret = mbedtls_ecdh_make_public( &ctx_srv, &srv_olen, srv_to_cli,
sizeof( srv_to_cli ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_make_public returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Client: read public key
*/
mbedtls_printf( " . Client: read public key..." );
fflush( stdout );
ret = mbedtls_ecdh_read_public( &ctx_cli, srv_to_cli,
sizeof( srv_to_cli ) );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_read_public returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Calculate secrets
*/
mbedtls_printf( " . Calculate secrets..." );
fflush( stdout );
ret = mbedtls_ecdh_calc_secret( &ctx_cli, &cli_olen, secret_cli,
sizeof( secret_cli ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_calc_secret returned %d\n",
ret );
goto exit;
}
ret = mbedtls_ecdh_calc_secret( &ctx_srv, &srv_olen, secret_srv,
sizeof( secret_srv ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_calc_secret returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Verification: are the computed secrets equal?
*/
mbedtls_printf( " . Check if both calculated secrets are equal..." );
fflush( stdout );
ret = memcmp( secret_srv, secret_cli, srv_olen );
if( ret != 0 || ( cli_olen != srv_olen ) )
{
mbedtls_printf( " failed\n ! Shared secrets not equal.\n" );
goto exit;
}
mbedtls_printf( " ok\n" );
exit_code = MBEDTLS_EXIT_SUCCESS;
exit:
mbedtls_ecdh_free( &ctx_srv );
mbedtls_ecdh_free( &ctx_cli );
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
mbedtls_exit( exit_code );
}
#endif /* MBEDTLS_ECDH_C && MBEDTLS_ECP_DP_CURVE25519_ENABLED &&
MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */
|
