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
|
#include "includes.h"
#include "session.h"
#include "auth.h"
#include "dbutil.h"
#include "buffer.h"
#include "ssh.h"
#include "packet.h"
#include "runopts.h"
void cli_authinitialise() {
memset(&ses.authstate, 0, sizeof(ses.authstate));
}
void cli_get_user() {
uid_t uid;
struct passwd *pw;
TRACE(("enter cli_get_user"));
if (cli_opts.username != NULL) {
ses.authstate.username = cli_opts.username;
} else {
uid = getuid();
pw = getpwuid(uid);
if (pw == NULL || pw->pw_name == NULL) {
dropbear_exit("Couldn't find username for current user");
}
ses.authstate.username = m_strdup(pw->pw_name);
}
TRACE(("leave cli_get_user: %s", ses.authstate.username));
}
/* Send a "none" auth request to get available methods */
void cli_auth_getmethods() {
TRACE(("enter cli_auth_getmethods"));
CHECKCLEARTOWRITE();
buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_REQUEST);
buf_putstring(ses.writepayload, ses.authstate.username,
strlen(ses.authstate.username));
buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION,
SSH_SERVICE_CONNECTION_LEN);
buf_putstring(ses.writepayload, "none", 4); /* 'none' method */
encrypt_packet();
cli_ses.state = USERAUTH_METHODS_SENT;
TRACE(("leave cli_auth_getmethods"));
}
void recv_msg_userauth_failure() {
unsigned char * methods = NULL;
unsigned char * tok = NULL;
unsigned int methlen = 0;
unsigned int partial = 0;
unsigned int i = 0;
TRACE(("<- MSG_USERAUTH_FAILURE"));
TRACE(("enter recv_msg_userauth_failure"));
methods = buf_getstring(ses.payload, &methlen);
partial = buf_getbyte(ses.payload);
if (partial) {
dropbear_log(LOG_INFO, "Authentication partially succeeded, more attempts required");
} else {
ses.authstate.failcount++;
}
TRACE(("Methods (len %d): '%s'", methlen, methods));
ses.authstate.authdone=0;
ses.authstate.authtypes=0;
/* Split with nulls rather than commas */
for (i = 0; i < methlen; i++) {
if (methods[i] == ',') {
methods[i] = '\0';
}
}
tok = methods; /* tok stores the next method we'll compare */
for (i = 0; i <= methlen; i++) {
if (methods[i] == '\0') {
TRACE(("auth method '%s'", tok));
#ifdef DROPBEAR_PUBKEY_AUTH
if (strncmp(AUTH_METHOD_PUBKEY, tok,
AUTH_METHOD_PUBKEY_LEN) == 0) {
ses.authstate.authtypes |= AUTH_TYPE_PUBKEY;
}
#endif
#ifdef DROPBEAR_PASSWORD_AUTH
if (strncmp(AUTH_METHOD_PASSWORD, tok,
AUTH_METHOD_PASSWORD_LEN) == 0) {
ses.authstate.authtypes |= AUTH_TYPE_PASSWORD;
}
#endif
tok = &methods[i+1]; /* Must make sure we don't use it after the
last loop, since it'll point to something
undefined */
}
}
cli_ses.state = USERAUTH_FAIL_RCVD;
TRACE(("leave recv_msg_userauth_failure"));
}
void recv_msg_userauth_success() {
TRACE(("received msg_userauth_success"));
ses.authstate.authdone = 1;
}
void cli_auth_try() {
TRACE(("enter cli_auth_try"));
int finished = 0;
CHECKCLEARTOWRITE();
/* XXX We hardcode that we try a pubkey first */
#ifdef DROPBEAR_PUBKEY_AUTH
if (ses.authstate.authtypes & AUTH_TYPE_PUBKEY) {
finished = cli_auth_pubkey();
}
#endif
#ifdef DROPBEAR_PASSWORD_AUTH
if (!finished && ses.authstate.authtypes & AUTH_TYPE_PASSWORD) {
finished = cli_auth_password();
}
#endif
if (!finished) {
dropbear_exit("No auth methods could be used.");
}
cli_ses.state = USERAUTH_REQ_SENT;
TRACE(("leave cli_auth_try"));
}
|
