1 /* $OpenBSD: x25519test.c,v 1.3 2022/12/01 13:55:22 tb Exp $ */
2 /*
3 * Copyright (c) 2015, Google Inc.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
12 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
14 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
15 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #include <stdint.h>
19 #include <stdio.h>
20 #include <string.h>
21
22 #include <openssl/curve25519.h>
23
24 static int
x25519_test(void)25 x25519_test(void)
26 {
27 /* Taken from https://tools.ietf.org/html/rfc7748#section-5.2 */
28 static const uint8_t kScalar1[32] = {
29 0xa5, 0x46, 0xe3, 0x6b, 0xf0, 0x52, 0x7c, 0x9d,
30 0x3b, 0x16, 0x15, 0x4b, 0x82, 0x46, 0x5e, 0xdd,
31 0x62, 0x14, 0x4c, 0x0a, 0xc1, 0xfc, 0x5a, 0x18,
32 0x50, 0x6a, 0x22, 0x44, 0xba, 0x44, 0x9a, 0xc4,
33 };
34 static const uint8_t kPoint1[32] = {
35 0xe6, 0xdb, 0x68, 0x67, 0x58, 0x30, 0x30, 0xdb,
36 0x35, 0x94, 0xc1, 0xa4, 0x24, 0xb1, 0x5f, 0x7c,
37 0x72, 0x66, 0x24, 0xec, 0x26, 0xb3, 0x35, 0x3b,
38 0x10, 0xa9, 0x03, 0xa6, 0xd0, 0xab, 0x1c, 0x4c,
39 };
40 static const uint8_t kExpected1[32] = {
41 0xc3, 0xda, 0x55, 0x37, 0x9d, 0xe9, 0xc6, 0x90,
42 0x8e, 0x94, 0xea, 0x4d, 0xf2, 0x8d, 0x08, 0x4f,
43 0x32, 0xec, 0xcf, 0x03, 0x49, 0x1c, 0x71, 0xf7,
44 0x54, 0xb4, 0x07, 0x55, 0x77, 0xa2, 0x85, 0x52,
45 };
46 static const uint8_t kScalar2[32] = {
47 0x4b, 0x66, 0xe9, 0xd4, 0xd1, 0xb4, 0x67, 0x3c,
48 0x5a, 0xd2, 0x26, 0x91, 0x95, 0x7d, 0x6a, 0xf5,
49 0xc1, 0x1b, 0x64, 0x21, 0xe0, 0xea, 0x01, 0xd4,
50 0x2c, 0xa4, 0x16, 0x9e, 0x79, 0x18, 0xba, 0x0d,
51 };
52 static const uint8_t kPoint2[32] = {
53 0xe5, 0x21, 0x0f, 0x12, 0x78, 0x68, 0x11, 0xd3,
54 0xf4, 0xb7, 0x95, 0x9d, 0x05, 0x38, 0xae, 0x2c,
55 0x31, 0xdb, 0xe7, 0x10, 0x6f, 0xc0, 0x3c, 0x3e,
56 0xfc, 0x4c, 0xd5, 0x49, 0xc7, 0x15, 0xa4, 0x93,
57 };
58 static const uint8_t kExpected2[32] = {
59 0x95, 0xcb, 0xde, 0x94, 0x76, 0xe8, 0x90, 0x7d,
60 0x7a, 0xad, 0xe4, 0x5c, 0xb4, 0xb8, 0x73, 0xf8,
61 0x8b, 0x59, 0x5a, 0x68, 0x79, 0x9f, 0xa1, 0x52,
62 0xe6, 0xf8, 0xf7, 0x64, 0x7a, 0xac, 0x79, 0x57,
63 };
64
65 uint8_t out[32];
66
67 X25519(out, kScalar1, kPoint1);
68 if (memcmp(kExpected1, out, sizeof(out)) != 0) {
69 fprintf(stderr, "X25519 test one failed.\n");
70 return 1;
71 }
72
73 X25519(out, kScalar2, kPoint2);
74 if (memcmp(kExpected2, out, sizeof(out)) != 0) {
75 fprintf(stderr, "X25519 test two failed.\n");
76 return 1;
77 }
78
79 return 0;
80 }
81
82 static int
x25519_iterated_test(void)83 x25519_iterated_test(void)
84 {
85 /* Taken from https://tools.ietf.org/html/rfc7748#section-5.2 */
86 static const uint8_t kExpected[32] = {
87 0x68, 0x4c, 0xf5, 0x9b, 0xa8, 0x33, 0x09, 0x55,
88 0x28, 0x00, 0xef, 0x56, 0x6f, 0x2f, 0x4d, 0x3c,
89 0x1c, 0x38, 0x87, 0xc4, 0x93, 0x60, 0xe3, 0x87,
90 0x5f, 0x2e, 0xb9, 0x4d, 0x99, 0x53, 0x2c, 0x51,
91 };
92
93 uint8_t scalar[32] = {9}, point[32] = {9}, out[32];
94 unsigned i;
95
96 for (i = 0; i < 1000; i++) {
97 X25519(out, scalar, point);
98 memcpy(point, scalar, sizeof(point));
99 memcpy(scalar, out, sizeof(scalar));
100 }
101
102 if (memcmp(kExpected, scalar, sizeof(kExpected)) != 0) {
103 fprintf(stderr, "Iterated X25519 test failed\n");
104 return 1;
105 }
106
107 return 0;
108 }
109
110 static int
x25519_small_order_test(void)111 x25519_small_order_test(void)
112 {
113 static const uint8_t kSmallOrderPoint[32] = {
114 0xe0, 0xeb, 0x7a, 0x7c, 0x3b, 0x41, 0xb8, 0xae,
115 0x16, 0x56, 0xe3, 0xfa, 0xf1, 0x9f, 0xc4, 0x6a,
116 0xda, 0x09, 0x8d, 0xeb, 0x9c, 0x32, 0xb1, 0xfd,
117 0x86, 0x62, 0x05, 0x16, 0x5f, 0x49, 0xb8, 0x00,
118 };
119
120 uint8_t out[32], private_key[32];
121
122 memset(private_key, 0x11, sizeof(private_key));
123 if (X25519(out, private_key, kSmallOrderPoint)) {
124 fprintf(stderr, "X25519 returned success with a small-order input.\n");
125 return 1;
126 }
127
128 return 0;
129 }
130
131 int
main(int argc,char ** argv)132 main(int argc, char **argv)
133 {
134 int failed = 0;
135
136 failed |= x25519_test();
137 failed |= x25519_iterated_test();
138 failed |= x25519_small_order_test();
139
140 return failed;
141 }
142