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
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
/* $Id: certproc.c,v 1.11 2018/07/28 15:25:23 tb Exp $ */
/*
* Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <openssl/pem.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/err.h>
#include "extern.h"
#define MARKER "-----BEGIN CERTIFICATE-----"
/*
* Convert an X509 certificate to a buffer of "sz".
* We don't guarantee that it's NUL-terminated.
* Returns NULL on failure.
*/
static char *
x509buf(X509 *x, size_t *sz)
{
BIO *bio;
char *p;
int ssz;
/* Convert X509 to PEM in BIO. */
if ((bio = BIO_new(BIO_s_mem())) == NULL) {
warnx("BIO_new");
return NULL;
} else if (!PEM_write_bio_X509(bio, x)) {
warnx("PEM_write_bio_X509");
BIO_free(bio);
return NULL;
}
/*
* Now convert bio to string.
* Make into NUL-terminated, just in case.
*/
if ((p = calloc(1, bio->num_write + 1)) == NULL) {
warn("calloc");
BIO_free(bio);
return NULL;
}
ssz = BIO_read(bio, p, bio->num_write);
if (ssz < 0 || (unsigned)ssz != bio->num_write) {
warnx("BIO_read");
BIO_free(bio);
return NULL;
}
*sz = ssz;
BIO_free(bio);
return p;
}
int
certproc(int netsock, int filesock)
{
char *csr = NULL, *chain = NULL, *url = NULL;
unsigned char *csrcp, *chaincp;
size_t csrsz, chainsz;
int i, rc = 0, idx = -1, cc;
enum certop op;
long lval;
X509 *x = NULL, *chainx = NULL;
X509_EXTENSION *ext = NULL;
X509V3_EXT_METHOD *method = NULL;
void *entries;
STACK_OF(CONF_VALUE) *val;
CONF_VALUE *nval;
/* File-system and sandbox jailing. */
ERR_load_crypto_strings();
if (pledge("stdio", NULL) == -1) {
warn("pledge");
goto out;
}
/* Read what the netproc wants us to do. */
op = CERT__MAX;
if ((lval = readop(netsock, COMM_CSR_OP)) == 0)
op = CERT_STOP;
else if (lval == CERT_REVOKE || lval == CERT_UPDATE)
op = lval;
if (CERT_STOP == op) {
rc = 1;
goto out;
} else if (CERT__MAX == op) {
warnx("unknown operation from netproc");
goto out;
}
/*
* Pass revocation right through to fileproc.
* If the reader is terminated, ignore it.
*/
if (CERT_REVOKE == op) {
if (writeop(filesock, COMM_CHAIN_OP, FILE_REMOVE) >= 0)
rc = 1;
goto out;
}
/*
* Wait until we receive the DER encoded (signed) certificate
* from the network process.
* Then convert the DER encoding into an X509 certificate.
*/
if ((csr = readbuf(netsock, COMM_CSR, &csrsz)) == NULL)
goto out;
csrcp = (u_char *)csr;
x = d2i_X509(NULL, (const u_char **)&csrcp, csrsz);
if (x == NULL) {
warnx("d2i_X509");
goto out;
}
/*
* Extract the CA Issuers from its NID.
* TODO: I have no idea what I'm doing.
*/
idx = X509_get_ext_by_NID(x, NID_info_access, idx);
if (idx >= 0 && (ext = X509_get_ext(x, idx)) != NULL)
method = (X509V3_EXT_METHOD *)X509V3_EXT_get(ext);
entries = X509_get_ext_d2i(x, NID_info_access, 0, 0);
if (method != NULL && entries != NULL) {
val = method->i2v(method, entries, 0);
for (i = 0; i < sk_CONF_VALUE_num(val); i++) {
nval = sk_CONF_VALUE_value(val, i);
if (strcmp(nval->name, "CA Issuers - URI"))
continue;
url = strdup(nval->value);
if (url == NULL) {
warn("strdup");
goto out;
}
break;
}
}
if (url == NULL) {
warnx("no CA issuer registered with certificate");
goto out;
}
/* Write the CA issuer to the netsock. */
if (writestr(netsock, COMM_ISSUER, url) <= 0)
goto out;
/* Read the full-chain back from the netsock. */
if ((chain = readbuf(netsock, COMM_CHAIN, &chainsz)) == NULL)
goto out;
/*
* Then check if the chain is PEM-encoded by looking to see if
* it begins with the PEM marker.
* If so, ship it as-is; otherwise, convert to a PEM encoded
* buffer and ship that.
* FIXME: if PEM, re-parse it.
*/
if (chainsz <= strlen(MARKER) ||
strncmp(chain, MARKER, strlen(MARKER))) {
chaincp = (u_char *)chain;
chainx = d2i_X509(NULL, (const u_char **)&chaincp, chainsz);
if (chainx == NULL) {
warnx("d2i_X509");
goto out;
}
free(chain);
if ((chain = x509buf(chainx, &chainsz)) == NULL)
goto out;
}
/* Allow reader termination to just push us out. */
if ((cc = writeop(filesock, COMM_CHAIN_OP, FILE_CREATE)) == 0)
rc = 1;
if (cc <= 0)
goto out;
if ((cc = writebuf(filesock, COMM_CHAIN, chain, chainsz)) == 0)
rc = 1;
if (cc <= 0)
goto out;
/*
* Next, convert the X509 to a buffer and send that.
* Reader failure doesn't change anything.
*/
free(chain);
if ((chain = x509buf(x, &chainsz)) == NULL)
goto out;
if (writebuf(filesock, COMM_CSR, chain, chainsz) < 0)
goto out;
rc = 1;
out:
close(netsock);
close(filesock);
X509_free(x);
X509_free(chainx);
free(csr);
free(url);
free(chain);
ERR_print_errors_fp(stderr);
ERR_free_strings();
return rc;
}
|
