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
|
#include <fcntl.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <uuid/uuid.h>
#include <json-c/json.h>
#define PAM_SM_AUTH
#define PAM_SM_ACCOUNT
#define PAM_SM_SESSION
#define PAM_SM_PASSWORD
#include <security/pam_modules.h>
#include <security/pam_appl.h>
#define DATABASE_FILE "/etc/agl/keys.json"
#define BLOCK_SIZE 4096
typedef struct header_
{
char mn[4];
size_t size;
} header;
int is_valid_mn(const char* v)
{
return v && v[0] == 'I' && v[1] == 'D' && v[2] == 'K' && v[3] == 'Y';
}
int read_device(const char* device, char** idkey)
{
int fd;
ssize_t sz;
header h;
printf("[PAM DEBUG] check_device %s...\n", device);
fd = open(device, O_RDONLY);
if (fd == -1)
{
printf("[PAM DEBUG] Failed to open the device %s!\n", device);
return PAM_SERVICE_ERR;
}
sz = read(fd, &h, sizeof(header));
if (sz != sizeof(header) || !is_valid_mn(h.mn) || h.size < 1) { close(fd); printf("[PAM DEBUG]: bad header!\n"); return PAM_SERVICE_ERR; }
printf("[PAM DEBUG]: data size=%lu\n", h.size);
*idkey = (char*)malloc(h.size + 1);
if (!*idkey) { close(fd); printf("[PAM DEBUG] Bad alloc!\n"); return PAM_SERVICE_ERR; }
memset(*idkey, 0, h.size + 1);
sz = read(fd, *idkey, h.size);
close(fd);
if (sz != h.size) { free(idkey); printf("[PAM DEBUG] Bad data read!\n"); return PAM_SERVICE_ERR; }
return PAM_SUCCESS;
}
int authenticate(pam_handle_t* pamh, const char* uuid)
{
struct json_object* database;
struct json_object* usb;
struct json_object* key;
database = json_object_from_file(DATABASE_FILE);
if (!database)
{
printf("[PAM DEBUG] Failed to parse the database\n");
return PAM_SERVICE_ERR;
}
if (json_object_object_get_ex(database, "usb", &usb))
{
if (json_object_object_get_ex(usb, uuid, &key))
{
printf("[PAM] Key found!\n");
printf("[PAM DEBUG] pam_set_item(\"%s\")\n", uuid);
pam_set_item(pamh, PAM_USER, uuid);
const char* pam_authtok;
if (pam_get_item(pamh, PAM_AUTHTOK, (const void**)&pam_authtok) == PAM_SUCCESS && !pam_authtok)
pam_set_item(pamh, PAM_AUTHTOK, uuid);
json_object_put(database);
return PAM_SUCCESS;
}
}
printf("[PAM] Key not found!\n");
if (database) json_object_put(database);
return PAM_AUTH_ERR;
}
int check_device(pam_handle_t* pamh, const char* device)
{
char* idkey;
int ret;
ret = read_device(device, &idkey);
if (ret != PAM_SUCCESS) return ret;
printf("[PAM DEBUG] Data read:\n%s\n", idkey);
json_object* idkey_json = json_tokener_parse(idkey);
if (!idkey_json)
{
free(idkey);
printf("[PAM DEBUG] Failed to parse json data!\n");
return PAM_SERVICE_ERR;
}
json_object* uuid_json;
if(!json_object_object_get_ex(idkey_json, "uuid", &uuid_json))
{
free(idkey);
printf("[PAM DEBUG] The json does not contains a valid uuid\n");
return PAM_SERVICE_ERR;
}
const char* uuid = json_object_get_string(uuid_json);
printf("[PAM DEBUG] uuid: %s\n", uuid);
ret = authenticate(pamh, uuid);
free(idkey);
json_object_put(idkey_json);
return ret;
}
void log_pam(const char* fname, int flags, int argc, const char** argv, const char* device)
{
printf("[PAM DEBUG] ---------- %s ----------\n", fname);
printf("[PAM DEBUG] flags: %d\n", flags);
for(int i = 0; i < argc; ++i)
{
printf("[PAM DEBUG] argv[%d]: %s\n", i, argv[i]);
}
printf("[PAM DEBUG] device: %s\n", device);
printf("[PAM DEBUG] ----------------------------------------\n");
}
/*!
@brief The pam_sm_authenticate function is the service module's implementation
of the pam_authenticate(3) interface.
This function performs the task of authenticating the user.
@param[in] pamh Unknown.
@param[in] flags PAM_SILENT and/or PAM_DISALLOW_NULL_AUTHTOK.
@return PAM_SUCCESS if ok.
*/
PAM_EXTERN int pam_sm_authenticate(pam_handle_t* pamh, int flags, int argc, const char** argv)
{
const char* device = pam_getenv(pamh, "DEVICE");
log_pam("pam_sm_authenticate", flags, argc, argv, device);
return check_device(pamh, device);
}
PAM_EXTERN int pam_sm_setcred(pam_handle_t* pamh, int flags, int argc, const char** argv)
{
log_pam("pam_sm_setcred", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
return PAM_SUCCESS;
}
PAM_EXTERN int pam_sm_acct_mgmt(pam_handle_t* pamh, int flags, int argc, const char** argv)
{
log_pam("pam_sm_acct_mgmt", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
return PAM_SUCCESS;
}
PAM_EXTERN int pam_sm_open_session(pam_handle_t* pamh, int flags, int argc, const char** argv)
{
log_pam("pam_sm_open_session", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
return PAM_SUCCESS;
}
PAM_EXTERN int pam_sm_close_session(pam_handle_t* pamh, int flags, int argc, const char** argv)
{
log_pam("pam_sm_close_session", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
return PAM_SUCCESS;
}
PAM_EXTERN int pam_sm_chauthtok(pam_handle_t* pamh, int flags, int argc, const char** argv)
{
log_pam("pam_sm_chauthtok", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
return PAM_SUCCESS;
}
|
