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
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/*
* debsig-verify - Debian package signature verification tool
*
* Copyright © 2000 Ben Collins <bcollins@debian.org>
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/*
* routines to parse gpg output
*/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <sys/stat.h>
#include <stdlib.h>
#include "debsig.h"
static int gpg_inited = 0;
/* Crazy damn hack to make sure gpg has created ~/.gnupg, else it will
* fail first time called */
static void gpg_init(void) {
int rc;
if (gpg_inited) return;
rc = system(GPG_PROG" --options /dev/null < /dev/null > /dev/null 2>&1");
if (rc < 0)
ds_fail_printf(DS_FAIL_INTERNAL, "error writing initializing gpg");
gpg_inited = 1;
}
char *getKeyID (const struct match *mtc) {
static char buf[2048];
FILE *ds;
char *c, *d, *ret = mtc->id;
if (ret == NULL)
return NULL;
gpg_init();
snprintf(buf, sizeof(buf) - 1, GPG_PROG" "GPG_ARGS_FMT" --list-packets -q "DEBSIG_KEYRINGS_FMT,
GPG_ARGS, originID, mtc->file);
if ((ds = popen(buf, "r")) == NULL) {
perror("gpg");
return NULL;
}
c = fgets(buf, sizeof(buf), ds);
while (c != NULL) {
if (!strncmp(buf, USER_MAGIC, strlen(USER_MAGIC))) {
if ((c = strchr(buf, '"')) == NULL) continue;
d = c + 1;
if ((c = strchr(d, '"')) == NULL) continue;
*c = '\0';
if (!strcmp(d, mtc->id)) {
c = fgets(buf, sizeof(buf), ds);
if (c == NULL) continue;
if (!strncmp(buf, SIG_MAGIC, strlen(SIG_MAGIC))) {
if ((c = strchr(buf, '\n')) != NULL)
*c = '\0';
d = strstr(buf, "keyid");
if (d) {
ret = d + 6;
break;
}
}
}
}
c = fgets(buf, sizeof(buf), ds);
}
pclose(ds);
if (ret == NULL)
ds_printf(DS_LEV_DEBUG, " getKeyID: failed for %s", mtc->id);
else
ds_printf(DS_LEV_DEBUG, " getKeyID: mapped %s -> %s", mtc->id, ret);
return ret;
}
char *getSigKeyID (const char *deb, const char *type) {
static char buf[2048];
int pread[2], pwrite[2], t;
off_t len = checkSigExist(type);
pid_t pid;
FILE *ds_read, *ds_write;
char *c, *ret = NULL;
if (!len)
return NULL;
gpg_init();
/* Fork for gpg, keeping a nice pipe to read/write from. */
if (pipe(pread) < 0)
ds_fail_printf(DS_FAIL_INTERNAL, "error creating a pipe");
if (pipe(pwrite) < 0)
ds_fail_printf(DS_FAIL_INTERNAL, "error creating a pipe");
/* I like file streams, so sue me :P */
if ((ds_read = fdopen(pread[0], "r")) == NULL ||
(ds_write = fdopen(pwrite[1], "w")) == NULL)
ds_fail_printf(DS_FAIL_INTERNAL, "error opening file stream for gpg");
if (!(pid = fork())) {
/* Here we go */
dup2(pread[1],1); close(pread[0]); close(pread[1]);
dup2(pwrite[0],0); close(pwrite[0]); close(pwrite[1]);
execl(GPG_PROG, "gpg", GPG_ARGS, "--list-packets", "-q", "-", NULL);
exit(1);
}
close(pread[1]); close(pwrite[0]);
/* First, let's feed gpg our signature. Don't forget, our call to
* checkSigExist() above positioned the deb_fs file pointer already. */
t = fread(buf, 1, sizeof(buf), deb_fs);
while(len > 0) {
if (t > len)
fwrite(buf, 1, len, ds_write);
else
fwrite(buf, 1, t, ds_write);
len -= t;
t = fread(buf, 1, sizeof(buf), deb_fs);
}
if (ferror(ds_write))
ds_fail_printf(DS_FAIL_INTERNAL, "error writing to gpg");
fclose(ds_write);
/* Now, let's see what gpg has to say about all this */
c = fgets(buf, sizeof(buf), ds_read);
while (c != NULL) {
if (!strncmp(buf, SIG_MAGIC, strlen(SIG_MAGIC))) {
if ((c = strchr(buf, '\n')) != NULL)
*c = '\0';
/* This is the only line we care about */
ret = strstr(buf, "keyid");
if (ret) {
ret += 6;
break;
}
}
c = fgets(buf, sizeof(buf), ds_read);
}
if (ferror(ds_read))
ds_fail_printf(DS_FAIL_INTERNAL, "error reading from gpg");
fclose(ds_read);
waitpid(pid, NULL, 0);
if (ret == NULL)
ds_printf(DS_LEV_DEBUG, " getSigKeyID: failed for %s", type);
else
ds_printf(DS_LEV_DEBUG, " getSigKeyID: got %s for %s key", ret, type);
return ret;
}
int gpgVerify(const char *data, struct match *mtc, const char *sig) {
char keyring[8192];
int status;
pid_t pid;
struct stat st;
gpg_init();
snprintf(keyring, sizeof(keyring) - 1, DEBSIG_KEYRINGS_FMT, originID, mtc->file);
if (stat(keyring, &st)) {
ds_printf(DS_LEV_DEBUG, "gpgVerify: could not stat %s", keyring);
return 0;
}
if (!(pid = fork())) {
if (DS_LEV_DEBUG < ds_debug_level) {
close(0); close(1); close(2);
}
execl(GPG_PROG, "gpg", GPG_ARGS, "--keyring",
keyring, "--verify", sig, data, NULL);
exit(1);
}
waitpid(pid, &status, 0);
if (!WIFEXITED(status) || WEXITSTATUS(status)) {
ds_printf(DS_LEV_DEBUG, "gpgVerify: gpg exited abnormally or with non-zero exit status");
return 0;
}
return 1;
}
|
