1 /*
2 * External backend for file-backed passwords
3 * Copyright (c) 2021, Patrick Steinhardt <ps@pks.im>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "includes.h"
10
11 #include "utils/common.h"
12 #include "utils/config.h"
13 #include "ext_password_i.h"
14
15
16 /**
17 * Data structure for the file-backed password backend.
18 */
19 struct ext_password_file_data {
20 char *path; /* path of the password file */
21 };
22
23
24 /**
25 * ext_password_file_init - Initialize file-backed password backend
26 * @params: Parameters passed by the user.
27 * Returns: Pointer to the initialized backend.
28 *
29 * This function initializes a new file-backed password backend. The user is
30 * expected to initialize this backend with the parameters being the path of
31 * the file that contains the passwords.
32 */
ext_password_file_init(const char * params)33 static void * ext_password_file_init(const char *params)
34 {
35 struct ext_password_file_data *data;
36
37 if (!params) {
38 wpa_printf(MSG_ERROR, "EXT PW FILE: no path given");
39 return NULL;
40 }
41
42 data = os_zalloc(sizeof(*data));
43 if (!data)
44 return NULL;
45
46 data->path = os_strdup(params);
47 if (!data->path) {
48 os_free(data);
49 return NULL;
50 }
51
52 return data;
53 }
54
55
56 /**
57 * ext_password_file_deinit - Deinitialize file-backed password backend
58 * @ctx: The file-backed password backend
59 *
60 * This function frees all data associated with the file-backed password
61 * backend.
62 */
ext_password_file_deinit(void * ctx)63 static void ext_password_file_deinit(void *ctx)
64 {
65 struct ext_password_file_data *data = ctx;
66
67 str_clear_free(data->path);
68 os_free(data);
69 }
70
71 /**
72 * ext_password_file_get - Retrieve password from the file-backed password backend
73 * @ctx: The file-backed password backend
74 * @name: Name of the password to retrieve
75 * Returns: Buffer containing the password if one was found or %NULL.
76 *
77 * This function tries to find a password identified by name in the password
78 * file. The password is expected to be stored in `NAME=PASSWORD` format.
79 * Comments and empty lines in the file are ignored. Invalid lines will cause
80 * an error message, but will not cause the function to fail.
81 */
ext_password_file_get(void * ctx,const char * name)82 static struct wpabuf * ext_password_file_get(void *ctx, const char *name)
83 {
84 struct ext_password_file_data *data = ctx;
85 struct wpabuf *password = NULL;
86 char buf[512], *pos;
87 int line = 0;
88 FILE *f;
89
90 f = fopen(data->path, "r");
91 if (!f) {
92 wpa_printf(MSG_ERROR,
93 "EXT PW FILE: could not open file '%s': %s",
94 data->path, strerror(errno));
95 return NULL;
96 }
97
98 wpa_printf(MSG_DEBUG, "EXT PW FILE: get(%s)", name);
99
100 while (wpa_config_get_line(buf, sizeof(buf), f, &line, &pos)) {
101 char *sep = os_strchr(pos, '=');
102
103 if (!sep) {
104 wpa_printf(MSG_ERROR, "Invalid password line %d.",
105 line);
106 continue;
107 }
108
109 if (!sep[1]) {
110 wpa_printf(MSG_ERROR, "No password for line %d.", line);
111 continue;
112
113 }
114
115 if (os_strncmp(name, pos, sep - pos) != 0)
116 continue;
117
118 password = wpabuf_alloc_copy(sep + 1, os_strlen(sep + 1));
119 goto done;
120 }
121
122 wpa_printf(MSG_ERROR, "Password for '%s' was not found.", name);
123
124 done:
125 forced_memzero(buf, sizeof(buf));
126 fclose(f);
127 return password;
128 }
129
130
131 const struct ext_password_backend ext_password_file = {
132 .name = "file",
133 .init = ext_password_file_init,
134 .deinit = ext_password_file_deinit,
135 .get = ext_password_file_get,
136 };
137