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
|
/*
* Dropbear - a SSH2 server
*
* Copyright (c) 2002,2003 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
/* Perform Ed25519 operations on data, including reading keys, signing and
* verification. */
#include "includes.h"
#include "dbutil.h"
#include "buffer.h"
#include "ssh.h"
#include "curve25519.h"
#include "ed25519.h"
#if DROPBEAR_ED25519
/* Load a public ed25519 key from a buffer, initialising the values.
* The key will have the same format as buf_put_ed25519_key.
* These should be freed with ed25519_key_free.
* Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
int buf_get_ed25519_pub_key(buffer *buf, dropbear_ed25519_key *key) {
unsigned int len;
TRACE(("enter buf_get_ed25519_pub_key"))
dropbear_assert(key != NULL);
buf_incrpos(buf, 4+SSH_SIGNKEY_ED25519_LEN); /* int + "ssh-ed25519" */
len = buf_getint(buf);
if (len != CURVE25519_LEN || buf->len - buf->pos < len) {
TRACE(("leave buf_get_ed25519_pub_key: failure"))
return DROPBEAR_FAILURE;
}
m_burn(key->priv, CURVE25519_LEN);
memcpy(key->pub, buf_getptr(buf, CURVE25519_LEN), CURVE25519_LEN);
buf_incrpos(buf, CURVE25519_LEN);
TRACE(("leave buf_get_ed25519_pub_key: success"))
return DROPBEAR_SUCCESS;
}
/* Same as buf_get_ed25519_pub_key, but reads private key at the end.
* Loads a public and private ed25519 key from a buffer
* Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
int buf_get_ed25519_priv_key(buffer *buf, dropbear_ed25519_key *key) {
unsigned int len;
TRACE(("enter buf_get_ed25519_priv_key"))
dropbear_assert(key != NULL);
buf_incrpos(buf, 4+SSH_SIGNKEY_ED25519_LEN); /* int + "ssh-ed25519" */
len = buf_getint(buf);
if (len != CURVE25519_LEN*2 || buf->len - buf->pos < len) {
TRACE(("leave buf_get_ed25519_priv_key: failure"))
return DROPBEAR_FAILURE;
}
memcpy(key->priv, buf_getptr(buf, CURVE25519_LEN), CURVE25519_LEN);
buf_incrpos(buf, CURVE25519_LEN);
memcpy(key->pub, buf_getptr(buf, CURVE25519_LEN), CURVE25519_LEN);
buf_incrpos(buf, CURVE25519_LEN);
TRACE(("leave buf_get_ed25519_priv_key: success"))
return DROPBEAR_SUCCESS;
}
/* Clear and free the memory used by a public or private key */
void ed25519_key_free(dropbear_ed25519_key *key) {
TRACE2(("enter ed25519_key_free"))
if (key == NULL) {
TRACE2(("leave ed25519_key_free: key == NULL"))
return;
}
m_burn(key->priv, CURVE25519_LEN);
m_free(key);
TRACE2(("leave ed25519_key_free"))
}
/* Put the public ed25519 key into the buffer in the required format */
void buf_put_ed25519_pub_key(buffer *buf, const dropbear_ed25519_key *key) {
TRACE(("enter buf_put_ed25519_pub_key"))
dropbear_assert(key != NULL);
buf_putstring(buf, SSH_SIGNKEY_ED25519, SSH_SIGNKEY_ED25519_LEN);
buf_putstring(buf, key->pub, CURVE25519_LEN);
TRACE(("leave buf_put_ed25519_pub_key"))
}
/* Put the public and private ed25519 key into the buffer in the required format */
void buf_put_ed25519_priv_key(buffer *buf, const dropbear_ed25519_key *key) {
TRACE(("enter buf_put_ed25519_priv_key"))
dropbear_assert(key != NULL);
buf_putstring(buf, SSH_SIGNKEY_ED25519, SSH_SIGNKEY_ED25519_LEN);
buf_putint(buf, CURVE25519_LEN*2);
buf_putbytes(buf, key->priv, CURVE25519_LEN);
buf_putbytes(buf, key->pub, CURVE25519_LEN);
TRACE(("leave buf_put_ed25519_priv_key"))
}
/* Sign the data presented with key, writing the signature contents
* to the buffer */
void buf_put_ed25519_sign(buffer* buf, const dropbear_ed25519_key *key, const buffer *data_buf) {
unsigned char s[64];
unsigned long slen = sizeof(s);
TRACE(("enter buf_put_ed25519_sign"))
dropbear_assert(key != NULL);
dropbear_ed25519_sign(data_buf->data, data_buf->len, s, &slen, key->priv, key->pub);
buf_putstring(buf, SSH_SIGNKEY_ED25519, SSH_SIGNKEY_ED25519_LEN);
buf_putstring(buf, s, slen);
TRACE(("leave buf_put_ed25519_sign"))
}
#if DROPBEAR_SIGNKEY_VERIFY
/* Verify a signature in buf, made on data by the key given.
* Returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
int buf_ed25519_verify(buffer *buf, const dropbear_ed25519_key *key, const buffer *data_buf) {
int ret = DROPBEAR_FAILURE;
unsigned char *s;
unsigned long slen;
TRACE(("enter buf_ed25519_verify"))
dropbear_assert(key != NULL);
slen = buf_getint(buf);
if (slen != 64 || buf->len - buf->pos < slen) {
TRACE(("leave buf_ed25519_verify: bad size"))
goto out;
}
s = buf_getptr(buf, slen);
if (dropbear_ed25519_verify(data_buf->data, data_buf->len,
s, slen, key->pub) == 0) {
/* signature is valid */
TRACE(("leave buf_ed25519_verify: success!"))
ret = DROPBEAR_SUCCESS;
}
out:
TRACE(("leave buf_ed25519_verify: ret %d", ret))
return ret;
}
#endif /* DROPBEAR_SIGNKEY_VERIFY */
#endif /* DROPBEAR_ED25519 */
|
