1 |
lefcha |
1.1 |
#include <stdlib.h> |
2 |
lefcha |
1.6 |
#include <unistd.h> |
3 |
|
|
#include <sys/types.h> |
4 |
lefcha |
1.1 |
#include <string.h> |
5 |
|
|
#include <errno.h> |
6 |
lefcha |
1.6 |
#include <sys/mman.h> |
7 |
|
|
#include <sys/time.h> |
8 |
|
|
#include <sys/resource.h> |
9 |
|
|
|
10 |
lefcha |
1.1 |
|
11 |
lefcha |
1.12 |
#include "config.h" |
12 |
lefcha |
1.1 |
#include "imapfilter.h" |
13 |
|
|
|
14 |
lefcha |
1.4 |
|
15 |
lefcha |
1.11 |
extern unsigned int options; |
16 |
lefcha |
1.13 |
|
17 |
lefcha |
1.12 |
#ifdef MEMORY_LOCK |
18 |
lefcha |
1.6 |
extern uid_t ruid, euid; |
19 |
lefcha |
1.13 |
|
20 |
lefcha |
1.12 |
#endif |
21 |
lefcha |
1.6 |
|
22 |
|
|
static secmem_t *smem = NULL; /* First node of secure memory linked list. */ |
23 |
lefcha |
1.7 |
|
24 |
lefcha |
1.6 |
|
25 |
lefcha |
1.1 |
/* |
26 |
lefcha |
1.3 |
* A malloc() that checks the results and dies in case of error. |
27 |
lefcha |
1.1 |
*/ |
28 |
lefcha |
1.13 |
void * |
29 |
|
|
xmalloc(size_t size) |
30 |
lefcha |
1.1 |
{ |
31 |
lefcha |
1.13 |
void *ptr; |
32 |
lefcha |
1.2 |
|
33 |
lefcha |
1.13 |
ptr = (void *)malloc(size); |
34 |
lefcha |
1.2 |
|
35 |
lefcha |
1.13 |
if (ptr == NULL) |
36 |
|
|
fatal(ERROR_MEMORY_ALLOCATION, |
37 |
|
|
"allocating memory; %s\n", strerror(errno)); |
38 |
lefcha |
1.2 |
|
39 |
lefcha |
1.13 |
return ptr; |
40 |
lefcha |
1.1 |
} |
41 |
|
|
|
42 |
|
|
|
43 |
|
|
/* |
44 |
lefcha |
1.3 |
* A realloc() that checks the results and dies in case of error. |
45 |
|
|
*/ |
46 |
lefcha |
1.13 |
void * |
47 |
|
|
xrealloc(void *ptr, size_t size) |
48 |
lefcha |
1.3 |
{ |
49 |
lefcha |
1.13 |
ptr = (void *)realloc(ptr, size); |
50 |
lefcha |
1.3 |
|
51 |
lefcha |
1.13 |
if (ptr == NULL) |
52 |
|
|
fatal(ERROR_MEMORY_ALLOCATION, |
53 |
|
|
"allocating memory; %s\n", strerror(errno)); |
54 |
lefcha |
1.3 |
|
55 |
lefcha |
1.13 |
return ptr; |
56 |
lefcha |
1.3 |
} |
57 |
|
|
|
58 |
|
|
|
59 |
|
|
/* |
60 |
lefcha |
1.5 |
* A free() that dies if fed with NULL pointer. |
61 |
|
|
*/ |
62 |
lefcha |
1.13 |
void |
63 |
|
|
xfree(void *ptr) |
64 |
lefcha |
1.5 |
{ |
65 |
lefcha |
1.13 |
if (ptr == NULL) |
66 |
|
|
fatal(ERROR_MEMORY_ALLOCATION, |
67 |
|
|
"NULL pointer given as argument"); |
68 |
|
|
free(ptr); |
69 |
lefcha |
1.5 |
} |
70 |
|
|
|
71 |
|
|
|
72 |
|
|
/* |
73 |
lefcha |
1.3 |
* A strdup() that checks the results and dies in case of error. |
74 |
lefcha |
1.1 |
*/ |
75 |
lefcha |
1.13 |
char * |
76 |
|
|
xstrdup(const char *s) |
77 |
lefcha |
1.1 |
{ |
78 |
lefcha |
1.13 |
char *cp; |
79 |
lefcha |
1.2 |
|
80 |
lefcha |
1.13 |
cp = strdup(s); |
81 |
lefcha |
1.2 |
|
82 |
lefcha |
1.13 |
if (cp == NULL) |
83 |
|
|
fatal(ERROR_MEMORY_ALLOCATION, |
84 |
|
|
"allocating memory; %s\n", strerror(errno)); |
85 |
lefcha |
1.2 |
|
86 |
lefcha |
1.13 |
return cp; |
87 |
lefcha |
1.6 |
} |
88 |
|
|
|
89 |
|
|
|
90 |
|
|
/* |
91 |
|
|
* Secure memory malloc(). Locks memory and keeps information about the |
92 |
|
|
* chunk that was allocated. |
93 |
|
|
*/ |
94 |
lefcha |
1.13 |
void * |
95 |
|
|
smalloc(size_t size) |
96 |
lefcha |
1.6 |
{ |
97 |
lefcha |
1.12 |
#ifdef MEMORY_LOCK |
98 |
lefcha |
1.13 |
int r; |
99 |
|
|
static int w = 0; |
100 |
|
|
|
101 |
lefcha |
1.12 |
#endif |
102 |
lefcha |
1.13 |
void *ptr; |
103 |
|
|
secmem_t *node; |
104 |
lefcha |
1.10 |
|
105 |
lefcha |
1.13 |
ptr = xmalloc(size); |
106 |
lefcha |
1.10 |
|
107 |
lefcha |
1.12 |
#ifdef MEMORY_LOCK |
108 |
lefcha |
1.13 |
seteuid(euid); /* Gain root privileges. */ |
109 |
|
|
r = mlock(ptr, size); |
110 |
|
|
seteuid(ruid); /* Drop root privileges. */ |
111 |
|
|
|
112 |
|
|
if (getuid() != geteuid()) |
113 |
|
|
fatal(ERROR_SETUID, "failed to drop privileges\n"); |
114 |
lefcha |
1.10 |
|
115 |
lefcha |
1.12 |
|
116 |
lefcha |
1.13 |
if (options & OPTION_WARNING && r == -1 && !w) { |
117 |
|
|
error("warning: using insecure memory\n"); |
118 |
|
|
w = 1; |
119 |
|
|
} |
120 |
lefcha |
1.12 |
#endif |
121 |
lefcha |
1.13 |
node = (secmem_t *) xmalloc(sizeof(secmem_t)); |
122 |
lefcha |
1.10 |
|
123 |
lefcha |
1.13 |
node->buf = ptr; |
124 |
|
|
node->size = size; |
125 |
|
|
node->prev = node->next = NULL; |
126 |
lefcha |
1.10 |
|
127 |
lefcha |
1.13 |
secmem_append(node); |
128 |
lefcha |
1.10 |
|
129 |
lefcha |
1.13 |
return ptr; |
130 |
lefcha |
1.6 |
} |
131 |
|
|
|
132 |
|
|
|
133 |
|
|
/* |
134 |
|
|
* Secure memory realloc(). Resize memory by allocating a new memory chunk |
135 |
|
|
* and NULL fill old memory, in order to protect sensitive data. |
136 |
|
|
*/ |
137 |
lefcha |
1.13 |
void * |
138 |
|
|
srealloc(void *ptr, size_t size) |
139 |
lefcha |
1.6 |
{ |
140 |
lefcha |
1.13 |
void *p; |
141 |
|
|
secmem_t *node; |
142 |
lefcha |
1.10 |
|
143 |
lefcha |
1.13 |
if (!(node = (secmem_t *) secmem_find(ptr))) { |
144 |
|
|
ptr = xrealloc(ptr, size); |
145 |
|
|
return ptr; |
146 |
|
|
} |
147 |
|
|
p = smalloc(size); |
148 |
|
|
memcpy(p, node->buf, min(node->size, size)); |
149 |
|
|
|
150 |
|
|
memset(node->buf, 0, node->size); |
151 |
|
|
secmem_remove(node); |
152 |
|
|
xfree(node->buf); |
153 |
|
|
xfree(node); |
154 |
lefcha |
1.10 |
|
155 |
lefcha |
1.13 |
return p; |
156 |
lefcha |
1.6 |
} |
157 |
|
|
|
158 |
|
|
|
159 |
|
|
/* |
160 |
|
|
* Secure memory free(). NULL fill memory before freeing it. |
161 |
|
|
*/ |
162 |
lefcha |
1.13 |
void |
163 |
|
|
sfree(void *ptr) |
164 |
lefcha |
1.6 |
{ |
165 |
lefcha |
1.13 |
secmem_t *node; |
166 |
lefcha |
1.10 |
|
167 |
lefcha |
1.13 |
if (!(node = (secmem_t *) secmem_find(ptr))) { |
168 |
|
|
xfree(ptr); |
169 |
|
|
return; |
170 |
|
|
} |
171 |
|
|
memset(node->buf, 0, node->size); |
172 |
|
|
secmem_remove(node); |
173 |
|
|
xfree(node->buf); |
174 |
|
|
xfree(node); |
175 |
lefcha |
1.6 |
} |
176 |
|
|
|
177 |
|
|
|
178 |
|
|
/* |
179 |
lefcha |
1.9 |
* Secure memory strdup(). Uses secure memory allocation. |
180 |
lefcha |
1.6 |
*/ |
181 |
lefcha |
1.13 |
char * |
182 |
|
|
sstrdup(const char *s) |
183 |
lefcha |
1.6 |
{ |
184 |
lefcha |
1.13 |
char *p; |
185 |
lefcha |
1.10 |
|
186 |
lefcha |
1.13 |
p = (char *)smalloc(strlen(s) + 1); |
187 |
|
|
xstrncpy(p, s, strlen(s)); |
188 |
lefcha |
1.10 |
|
189 |
lefcha |
1.13 |
return p; |
190 |
lefcha |
1.6 |
} |
191 |
|
|
|
192 |
|
|
|
193 |
|
|
/* |
194 |
|
|
* Append information about the newly allocated memory buffer. |
195 |
|
|
*/ |
196 |
lefcha |
1.13 |
void |
197 |
|
|
secmem_append(secmem_t * node) |
198 |
lefcha |
1.6 |
{ |
199 |
lefcha |
1.13 |
secmem_t *pos; |
200 |
|
|
secmem_t **app; |
201 |
lefcha |
1.10 |
|
202 |
lefcha |
1.13 |
app = &smem; |
203 |
|
|
pos = smem; |
204 |
lefcha |
1.6 |
|
205 |
lefcha |
1.13 |
while (pos) { |
206 |
|
|
node->prev = pos; |
207 |
|
|
app = &(pos->next); |
208 |
|
|
pos = pos->next; |
209 |
|
|
} |
210 |
lefcha |
1.10 |
|
211 |
lefcha |
1.13 |
*app = node; |
212 |
lefcha |
1.6 |
} |
213 |
|
|
|
214 |
|
|
|
215 |
|
|
/* |
216 |
|
|
* Find the record of a memory buffer in the secure memory linked list. |
217 |
|
|
*/ |
218 |
lefcha |
1.13 |
secmem_t * |
219 |
|
|
secmem_find(void *ptr) |
220 |
lefcha |
1.6 |
{ |
221 |
lefcha |
1.13 |
secmem_t *pos; |
222 |
lefcha |
1.10 |
|
223 |
lefcha |
1.13 |
pos = smem; |
224 |
lefcha |
1.10 |
|
225 |
lefcha |
1.13 |
while (pos != NULL && pos->buf != ptr) |
226 |
|
|
pos = pos->next; |
227 |
lefcha |
1.10 |
|
228 |
lefcha |
1.13 |
return pos; |
229 |
lefcha |
1.6 |
} |
230 |
lefcha |
1.10 |
|
231 |
lefcha |
1.6 |
|
232 |
|
|
/* |
233 |
|
|
* Remove a record of a secure memory buffer. |
234 |
|
|
*/ |
235 |
lefcha |
1.13 |
void |
236 |
|
|
secmem_remove(secmem_t * node) |
237 |
lefcha |
1.6 |
{ |
238 |
lefcha |
1.13 |
if (node->prev != NULL) |
239 |
|
|
node->prev->next = node->next; |
240 |
|
|
if (node->next != NULL) |
241 |
|
|
node->next->prev = node->prev; |
242 |
lefcha |
1.14 |
if (smem == node) |
243 |
|
|
smem = node->next; |
244 |
|
|
|
245 |
lefcha |
1.6 |
} |
246 |
|
|
|
247 |
|
|
|
248 |
|
|
/* |
249 |
|
|
* Overwrite/clear all secure memory. |
250 |
|
|
*/ |
251 |
lefcha |
1.13 |
void |
252 |
|
|
secmem_clear(void) |
253 |
lefcha |
1.6 |
{ |
254 |
lefcha |
1.14 |
secmem_t *p, *t; |
255 |
lefcha |
1.10 |
|
256 |
lefcha |
1.14 |
for (p = smem; p != NULL; p = t) { |
257 |
|
|
t = p->next; |
258 |
|
|
sfree(p->buf); |
259 |
|
|
} |
260 |
lefcha |
1.6 |
} |
261 |
|
|
|
262 |
|
|
|
263 |
lefcha |
1.12 |
#ifdef MEMORY_LOCK |
264 |
lefcha |
1.6 |
/* |
265 |
lefcha |
1.8 |
* Lock memory of allocated buffers. |
266 |
|
|
*/ |
267 |
lefcha |
1.13 |
void |
268 |
|
|
secmem_lock(void) |
269 |
lefcha |
1.8 |
{ |
270 |
lefcha |
1.13 |
secmem_t *p; |
271 |
lefcha |
1.8 |
|
272 |
lefcha |
1.13 |
seteuid(euid); /* Gain root privileges. */ |
273 |
|
|
for (p = smem; p != NULL; p = p->next) |
274 |
|
|
mlock(p->buf, p->size); |
275 |
|
|
seteuid(ruid); /* Drop root privileges. */ |
276 |
lefcha |
1.8 |
|
277 |
lefcha |
1.13 |
if (getuid() != geteuid()) |
278 |
|
|
fatal(ERROR_SETUID, "failed to drop privileges\n"); |
279 |
lefcha |
1.8 |
} |
280 |
lefcha |
1.12 |
|
281 |
|
|
#endif |
282 |
lefcha |
1.8 |
|
283 |
|
|
|
284 |
|
|
/* |
285 |
lefcha |
1.9 |
* Disable core file dumping. |
286 |
lefcha |
1.6 |
*/ |
287 |
lefcha |
1.13 |
void |
288 |
|
|
corefile_disable(void) |
289 |
lefcha |
1.6 |
{ |
290 |
lefcha |
1.13 |
struct rlimit rl; |
291 |
lefcha |
1.7 |
|
292 |
lefcha |
1.13 |
getrlimit(RLIMIT_CORE, &rl); |
293 |
lefcha |
1.10 |
|
294 |
lefcha |
1.13 |
rl.rlim_cur = rl.rlim_max = 0; |
295 |
|
|
setrlimit(RLIMIT_CORE, &rl); |
296 |
lefcha |
1.2 |
} |