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 |
1.11.2.1 |
#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 |
1.11.2.1 |
#ifdef MEMORY_LOCK |
17 |
lefcha |
1.6 |
extern uid_t ruid, euid; |
18 |
lefcha |
1.11.2.1 |
#endif |
19 |
lefcha |
1.6 |
|
20 |
|
|
static secmem_t *smem = NULL; /* First node of secure memory linked list. */ |
21 |
lefcha |
1.7 |
|
22 |
lefcha |
1.6 |
|
23 |
lefcha |
1.1 |
/* |
24 |
lefcha |
1.3 |
* A malloc() that checks the results and dies in case of error. |
25 |
lefcha |
1.1 |
*/ |
26 |
|
|
void *xmalloc(size_t size) |
27 |
|
|
{ |
28 |
|
|
void *ptr; |
29 |
lefcha |
1.2 |
|
30 |
lefcha |
1.10 |
ptr = (void *)malloc(size); |
31 |
lefcha |
1.2 |
|
32 |
lefcha |
1.1 |
if (!ptr) |
33 |
|
|
fatal(ERROR_MEMORY_ALLOCATION, |
34 |
|
|
"imapfilter: allocating memory; %s\n", strerror(errno)); |
35 |
lefcha |
1.2 |
|
36 |
lefcha |
1.1 |
return ptr; |
37 |
|
|
} |
38 |
|
|
|
39 |
|
|
|
40 |
|
|
/* |
41 |
lefcha |
1.3 |
* A realloc() that checks the results and dies in case of error. |
42 |
|
|
*/ |
43 |
|
|
void *xrealloc(void *ptr, size_t size) |
44 |
|
|
{ |
45 |
lefcha |
1.10 |
ptr = (void *)realloc(ptr, size); |
46 |
lefcha |
1.3 |
|
47 |
|
|
if (!ptr) |
48 |
|
|
fatal(ERROR_MEMORY_ALLOCATION, |
49 |
|
|
"imapfilter: allocating memory; %s\n", strerror(errno)); |
50 |
|
|
|
51 |
|
|
return ptr; |
52 |
|
|
} |
53 |
|
|
|
54 |
|
|
|
55 |
|
|
/* |
56 |
lefcha |
1.5 |
* A free() that dies if fed with NULL pointer. |
57 |
|
|
*/ |
58 |
|
|
void xfree(void *ptr) |
59 |
|
|
{ |
60 |
|
|
if (!ptr) |
61 |
|
|
fatal(ERROR_MEMORY_ALLOCATION, |
62 |
|
|
"imapfilter: NULL pointer given as argument"); |
63 |
|
|
free(ptr); |
64 |
|
|
} |
65 |
|
|
|
66 |
|
|
|
67 |
|
|
/* |
68 |
lefcha |
1.3 |
* A strdup() that checks the results and dies in case of error. |
69 |
lefcha |
1.1 |
*/ |
70 |
|
|
char *xstrdup(const char *s) |
71 |
|
|
{ |
72 |
|
|
char *cp; |
73 |
lefcha |
1.2 |
|
74 |
lefcha |
1.1 |
cp = strdup(s); |
75 |
lefcha |
1.2 |
|
76 |
lefcha |
1.1 |
if (!cp) |
77 |
|
|
fatal(ERROR_MEMORY_ALLOCATION, |
78 |
|
|
"imapfilter: allocating memory; %s\n", strerror(errno)); |
79 |
lefcha |
1.2 |
|
80 |
lefcha |
1.1 |
return cp; |
81 |
lefcha |
1.6 |
} |
82 |
|
|
|
83 |
|
|
|
84 |
|
|
/* |
85 |
|
|
* Secure memory malloc(). Locks memory and keeps information about the |
86 |
|
|
* chunk that was allocated. |
87 |
|
|
*/ |
88 |
|
|
void *smalloc(size_t size) |
89 |
|
|
{ |
90 |
lefcha |
1.11.2.1 |
#ifdef MEMORY_LOCK |
91 |
lefcha |
1.6 |
int r; |
92 |
|
|
static int w = 0; |
93 |
lefcha |
1.11.2.1 |
#endif |
94 |
|
|
void *ptr; |
95 |
lefcha |
1.6 |
secmem_t *node; |
96 |
lefcha |
1.10 |
|
97 |
lefcha |
1.6 |
ptr = xmalloc(size); |
98 |
lefcha |
1.10 |
|
99 |
lefcha |
1.11.2.1 |
#ifdef MEMORY_LOCK |
100 |
lefcha |
1.6 |
seteuid(euid); /* Gain root privileges. */ |
101 |
|
|
r = mlock(ptr, size); |
102 |
|
|
seteuid(ruid); /* Drop root privileges. */ |
103 |
lefcha |
1.10 |
|
104 |
lefcha |
1.6 |
if (getuid() != geteuid()) |
105 |
|
|
fatal(ERROR_SETUID, "imapfilter: failed to drop privileges\n"); |
106 |
lefcha |
1.10 |
|
107 |
lefcha |
1.11.2.1 |
|
108 |
lefcha |
1.11 |
if (options & OPTION_WARNING && r && !w) { |
109 |
lefcha |
1.6 |
error("imapfilter: warning: using insecure memory\n"); |
110 |
|
|
w = 1; |
111 |
|
|
} |
112 |
lefcha |
1.11.2.1 |
#endif |
113 |
lefcha |
1.6 |
node = (secmem_t *) xmalloc(sizeof(secmem_t)); |
114 |
lefcha |
1.10 |
|
115 |
lefcha |
1.6 |
node->buf = ptr; |
116 |
|
|
node->size = size; |
117 |
|
|
node->prev = node->next = NULL; |
118 |
lefcha |
1.10 |
|
119 |
lefcha |
1.6 |
secmem_append(node); |
120 |
lefcha |
1.10 |
|
121 |
lefcha |
1.6 |
return ptr; |
122 |
|
|
} |
123 |
|
|
|
124 |
|
|
|
125 |
|
|
/* |
126 |
|
|
* Secure memory realloc(). Resize memory by allocating a new memory chunk |
127 |
|
|
* and NULL fill old memory, in order to protect sensitive data. |
128 |
|
|
*/ |
129 |
|
|
void *srealloc(void *ptr, size_t size) |
130 |
|
|
{ |
131 |
|
|
void *p; |
132 |
|
|
secmem_t *node; |
133 |
lefcha |
1.10 |
|
134 |
lefcha |
1.6 |
if (!(node = (secmem_t *) secmem_find(ptr))) { |
135 |
|
|
ptr = xrealloc(ptr, size); |
136 |
|
|
return ptr; |
137 |
|
|
} |
138 |
|
|
p = smalloc(size); |
139 |
|
|
memcpy(p, node->buf, min(node->size, size)); |
140 |
lefcha |
1.10 |
|
141 |
lefcha |
1.6 |
memset(node->buf, 0, node->size); |
142 |
|
|
secmem_remove(node); |
143 |
|
|
xfree(node->buf); |
144 |
|
|
xfree(node); |
145 |
lefcha |
1.10 |
|
146 |
lefcha |
1.6 |
return p; |
147 |
|
|
} |
148 |
|
|
|
149 |
|
|
|
150 |
|
|
/* |
151 |
|
|
* Secure memory free(). NULL fill memory before freeing it. |
152 |
|
|
*/ |
153 |
|
|
void sfree(void *ptr) |
154 |
|
|
{ |
155 |
|
|
secmem_t *node; |
156 |
lefcha |
1.10 |
|
157 |
lefcha |
1.6 |
if (!(node = (secmem_t *) secmem_find(ptr))) { |
158 |
|
|
xfree(ptr); |
159 |
|
|
return; |
160 |
|
|
} |
161 |
|
|
memset(node->buf, 0, node->size); |
162 |
|
|
|
163 |
|
|
secmem_remove(node); |
164 |
|
|
xfree(node->buf); |
165 |
|
|
xfree(node); |
166 |
|
|
} |
167 |
|
|
|
168 |
|
|
|
169 |
|
|
/* |
170 |
lefcha |
1.9 |
* Secure memory strdup(). Uses secure memory allocation. |
171 |
lefcha |
1.6 |
*/ |
172 |
|
|
char *sstrdup(const char *s) |
173 |
|
|
{ |
174 |
|
|
char *p; |
175 |
lefcha |
1.10 |
|
176 |
|
|
p = (char *)smalloc(strlen(s) + 1); |
177 |
lefcha |
1.6 |
xstrncpy(p, s, strlen(s)); |
178 |
lefcha |
1.10 |
|
179 |
lefcha |
1.6 |
return p; |
180 |
|
|
} |
181 |
|
|
|
182 |
|
|
|
183 |
|
|
/* |
184 |
|
|
* Append information about the newly allocated memory buffer. |
185 |
|
|
*/ |
186 |
lefcha |
1.10 |
void secmem_append(secmem_t * node) |
187 |
lefcha |
1.6 |
{ |
188 |
|
|
secmem_t *pos; |
189 |
|
|
secmem_t **app; |
190 |
lefcha |
1.10 |
|
191 |
lefcha |
1.6 |
app = &smem; |
192 |
|
|
pos = smem; |
193 |
|
|
|
194 |
|
|
while (pos) { |
195 |
|
|
node->prev = pos; |
196 |
|
|
app = &(pos->next); |
197 |
|
|
pos = pos->next; |
198 |
|
|
} |
199 |
lefcha |
1.10 |
|
200 |
lefcha |
1.6 |
*app = node; |
201 |
|
|
} |
202 |
|
|
|
203 |
|
|
|
204 |
|
|
/* |
205 |
|
|
* Find the record of a memory buffer in the secure memory linked list. |
206 |
|
|
*/ |
207 |
|
|
secmem_t *secmem_find(void *ptr) |
208 |
|
|
{ |
209 |
|
|
secmem_t *pos; |
210 |
lefcha |
1.10 |
|
211 |
lefcha |
1.6 |
pos = smem; |
212 |
lefcha |
1.10 |
|
213 |
|
|
while (pos && pos->buf != ptr) |
214 |
lefcha |
1.6 |
pos = pos->next; |
215 |
lefcha |
1.10 |
|
216 |
lefcha |
1.6 |
return pos; |
217 |
|
|
} |
218 |
lefcha |
1.10 |
|
219 |
lefcha |
1.6 |
|
220 |
|
|
/* |
221 |
|
|
* Remove a record of a secure memory buffer. |
222 |
|
|
*/ |
223 |
lefcha |
1.10 |
void secmem_remove(secmem_t * node) |
224 |
lefcha |
1.6 |
{ |
225 |
|
|
if (node->prev) |
226 |
|
|
node->prev->next = node->next; |
227 |
|
|
if (node->next) |
228 |
|
|
node->next->prev = node->prev; |
229 |
|
|
} |
230 |
|
|
|
231 |
|
|
|
232 |
|
|
/* |
233 |
|
|
* Overwrite/clear all secure memory. |
234 |
|
|
*/ |
235 |
|
|
void secmem_clear(void) |
236 |
|
|
{ |
237 |
|
|
secmem_t *p; |
238 |
lefcha |
1.10 |
|
239 |
lefcha |
1.6 |
for (p = smem; p; p = p->next) |
240 |
|
|
sfree(p); |
241 |
|
|
} |
242 |
|
|
|
243 |
|
|
|
244 |
lefcha |
1.11.2.1 |
#ifdef MEMORY_LOCK |
245 |
lefcha |
1.6 |
/* |
246 |
lefcha |
1.8 |
* Lock memory of allocated buffers. |
247 |
|
|
*/ |
248 |
|
|
void secmem_lock(void) |
249 |
|
|
{ |
250 |
|
|
secmem_t *p; |
251 |
|
|
|
252 |
|
|
seteuid(euid); /* Gain root privileges. */ |
253 |
|
|
for (p = smem; p; p = p->next) |
254 |
|
|
mlock(p->buf, p->size); |
255 |
|
|
seteuid(ruid); /* Drop root privileges. */ |
256 |
|
|
|
257 |
|
|
if (getuid() != geteuid()) |
258 |
|
|
fatal(ERROR_SETUID, "imapfilter: failed to drop privileges\n"); |
259 |
|
|
} |
260 |
lefcha |
1.11.2.1 |
|
261 |
|
|
#endif |
262 |
lefcha |
1.8 |
|
263 |
|
|
|
264 |
|
|
/* |
265 |
lefcha |
1.9 |
* Disable core file dumping. |
266 |
lefcha |
1.6 |
*/ |
267 |
|
|
void corefile_disable(void) |
268 |
|
|
{ |
269 |
lefcha |
1.7 |
struct rlimit rl; |
270 |
|
|
|
271 |
|
|
getrlimit(RLIMIT_CORE, &rl); |
272 |
lefcha |
1.10 |
|
273 |
lefcha |
1.7 |
rl.rlim_cur = rl.rlim_max = 0; |
274 |
|
|
setrlimit(RLIMIT_CORE, &rl); |
275 |
lefcha |
1.2 |
} |