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
|
--- a/svr-authpubkey.c
+++ b/svr-authpubkey.c
@@ -77,6 +77,13 @@ static void send_msg_userauth_pk_ok(cons
const unsigned char* keyblob, unsigned int keybloblen);
static int checkfileperm(char * filename);
+static const char * const global_authkeys_dir = "/etc/dropbear";
+static const int n_global_authkeys_dir = 14; /* + 1 extra byte */
+static const char * const user_authkeys_dir = ".ssh";
+static const int n_user_authkeys_dir = 5; /* + 1 extra byte */
+static const char * const authkeys_file = "authorized_keys";
+static const int n_authkeys_file = 16; /* + 1 extra byte */
+
/* process a pubkey auth request, sending success or failure message as
* appropriate */
void svr_auth_pubkey(int valid_user) {
@@ -439,14 +446,21 @@ static int checkpubkey(const char* keyal
if (checkpubkeyperms() == DROPBEAR_FAILURE) {
TRACE(("bad authorized_keys permissions, or file doesn't exist"))
} else {
- /* we don't need to check pw and pw_dir for validity, since
- * its been done in checkpubkeyperms. */
- len = strlen(ses.authstate.pw_dir);
- /* allocate max required pathname storage,
- * = path + "/.ssh/authorized_keys" + '\0' = pathlen + 22 */
- filename = m_malloc(len + 22);
- snprintf(filename, len + 22, "%s/.ssh/authorized_keys",
- ses.authstate.pw_dir);
+ if (ses.authstate.pw_uid == 0) {
+ len = n_global_authkeys_dir + n_authkeys_file;
+ filename = m_malloc(len);
+ snprintf(filename, len, "%s/%s", global_authkeys_dir, authkeys_file);
+ } else {
+ /* we don't need to check pw and pw_dir for validity, since
+ * its been done in checkpubkeyperms. */
+ len = strlen(ses.authstate.pw_dir);
+ /* allocate max required pathname storage,
+ * = path + "/.ssh/authorized_keys" + '\0' = pathlen + 22 */
+ len += n_user_authkeys_dir + n_authkeys_file + 1;
+ filename = m_malloc(len);
+ snprintf(filename, len, "%s/%s/%s", ses.authstate.pw_dir,
+ user_authkeys_dir, authkeys_file);
+ }
authfile = fopen(filename, "r");
if (!authfile) {
@@ -520,27 +534,41 @@ static int checkpubkeyperms() {
goto out;
}
- /* allocate max required pathname storage,
- * = path + "/.ssh/authorized_keys" + '\0' = pathlen + 22 */
- len += 22;
- filename = m_malloc(len);
- strlcpy(filename, ses.authstate.pw_dir, len);
+ if (ses.authstate.pw_uid == 0) {
+ if (checkfileperm(global_authkeys_dir) != DROPBEAR_SUCCESS) {
+ goto out;
+ }
- /* check ~ */
- if (checkfileperm(filename) != DROPBEAR_SUCCESS) {
- goto out;
- }
+ len = n_global_authkeys_dir + n_authkeys_file;
+ filename = m_malloc(len);
- /* check ~/.ssh */
- strlcat(filename, "/.ssh", len);
- if (checkfileperm(filename) != DROPBEAR_SUCCESS) {
- goto out;
- }
+ snprintf(filename, len, "%s/%s", global_authkeys_dir, authkeys_file);
+ if (checkfileperm(filename) != DROPBEAR_SUCCESS) {
+ goto out;
+ }
+ } else {
+ /* check ~ */
+ if (checkfileperm(ses.authstate.pw_dir) != DROPBEAR_SUCCESS) {
+ goto out;
+ }
- /* now check ~/.ssh/authorized_keys */
- strlcat(filename, "/authorized_keys", len);
- if (checkfileperm(filename) != DROPBEAR_SUCCESS) {
- goto out;
+ /* allocate max required pathname storage,
+ * = path + "/.ssh/authorized_keys" + '\0' = pathlen + 22 */
+ len += n_user_authkeys_dir + n_authkeys_file + 1;
+ filename = m_malloc(len);
+
+ /* check ~/.ssh */
+ snprintf(filename, len, "%s/%s", ses.authstate.pw_dir, user_authkeys_dir);
+ if (checkfileperm(filename) != DROPBEAR_SUCCESS) {
+ goto out;
+ }
+
+ /* now check ~/.ssh/authorized_keys */
+ snprintf(filename, len, "%s/%s/%s", ses.authstate.pw_dir,
+ user_authkeys_dir, authkeys_file);
+ if (checkfileperm(filename) != DROPBEAR_SUCCESS) {
+ goto out;
+ }
}
/* file looks ok, return success */
|
