1 /*
2  * Copyright (C) 2015 Red Hat, Inc.
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with this library.  If not, see
16  * <http://www.gnu.org/licenses/>.
17  *
18  * Author: Daniel P. Berrange <berrange@redhat.com>
19  */
20 
21 #include "qemu/osdep.h"
22 
23 #include "crypto-tls-x509-helpers.h"
24 #include "crypto/init.h"
25 #include "qemu/sockets.h"
26 
27 /*
28  * This stores some static data that is needed when
29  * encoding extensions in the x509 certs
30  */
31 asn1_node pkix_asn1;
32 
33 /*
34  * To avoid consuming random entropy to generate keys,
35  * here's one we prepared earlier :-)
36  */
37 gnutls_x509_privkey_t privkey;
38 # define PRIVATE_KEY \
39     "-----BEGIN RSA PRIVATE KEY-----\n" \
40     "MIIG5AIBAAKCAYEAyjWyLSNm5PZvYUKUcDWGqbLX10b2ood+YaFjWSnJrqx/q3qh\n" \
41     "rVGBJglD25AJENJsmZF3zPP1oMhfIxsXu63Hdkb6Rdlc2RUoUP34x9VC1izH25mR\n" \
42     "6c8DPDp1d6IraZ/llDMI1HsBFz0qGWtvOHgm815XG4PAr/N8rDsuqfv/cJ01KlnO\n" \
43     "0OdO5QRXCJf9g/dYd41MPu7wOXk9FqjQlmRoP59HgtJ+zUpE4z+Keruw9cMT9VJj\n" \
44     "0oT+pQ9ysenqeZ3gbT224T1khrEhT5kifhtFLNyDssRchUUWH0hiqoOO1vgb+850\n" \
45     "W6/1VdxvuPam48py4diSPi1Vip8NITCOBaX9FIpVp4Ruw4rTPVMNMjq9Cpx/DwMP\n" \
46     "9MbfXfnaVaZaMrmq67/zPhl0eVbUrecH2hQ3ZB9oIF4GkNskzlWF5+yPy6zqk304\n" \
47     "AKaiFR6jRyh3YfHo2XFqV8x/hxdsIEXOtEUGhSIcpynsW+ckUCartzu7xbhXjd4b\n" \
48     "kxJT89+riPFYij09AgMBAAECggGBAKyFkaZXXROeejrmHlV6JZGlp+fhgM38gkRz\n" \
49     "+Jp7P7rLLAY3E7gXIPQ91WqAAmwazFNdvHPd9USfkCQYmnAi/VoZhrCPmlsQZRxt\n" \
50     "A5QjjOnEvSPMa6SrXZxGWDCg6R8uMCb4P+FhrPWR1thnRDZOtRTQ+crc50p3mHgt\n" \
51     "6ktXWIJRbqnag8zSfQqCYGtRmhe8sfsWT+Yl4El4+jjaAVU/B364u7+PLmaiphGp\n" \
52     "BdJfTsTwEpgtGkPj+osDmhzXcZkfq3V+fz5JLkemsCiQKmn4VJRpg8c3ZmE8NPNt\n" \
53     "gRtGWZ4W3WKDvhotT65WpQx4+6R8Duux/blNPBmH1Upmwd7kj7GYFBArbCjgd9PT\n" \
54     "xgfCSUZpgOZHHkcgSB+022a8XncXna7WYYij28SLtwImFyu0nNtqECFQHH5u+k6C\n" \
55     "LRYBSN+3t3At8dQuk01NVrJBndmjmXRfxpqUtTdeaNgVpdUYRY98s30G68NYGSra\n" \
56     "aEvhhRSghkcLNetkobpY9pUgeqW/tQKBwQDZHHK9nDMt/zk1TxtILeUSitPXcv1/\n" \
57     "8ufXqO0miHdH23XuXhIEA6Ef26RRVGDGgpjkveDJK/1w5feJ4H/ni4Vclil/cm38\n" \
58     "OwRqjjd7ElHJX6JQbsxEx/gNTk5/QW1iAL9TXUalgepsSXYT6AJ0/CJv0jmJSJ36\n" \
59     "YoKMOM8uqzb2KhN6i+RlJRi5iY53kUhWTJq5ArWvNhUzQNSYODI4bNxlsKSBL2Ik\n" \
60     "LZ5QKHuaEjQet0IlPlfIb4PzMm8CHa/urOcCgcEA7m3zW/lL5bIFoKPjWig5Lbn1\n" \
61     "aHfrG2ngqzWtgWtfZqMH8OkZc1Mdhhmvd46titjiLjeI+UP/uHXR0068PnrNngzl\n" \
62     "tTgwlakzu+bWzqhBm1F+3/341st/FEk07r0P/3/PhezVjwfO8c8Exj7pLxH4wrH0\n" \
63     "ROHgDbClmlJRu6OO78wk1+Vapf5DWa8YfA+q+fdvr7KvgGyytheKMT/b/dsqOq7y\n" \
64     "qZPjmaJKWAvV3RWG8lWHFSdHx2IAHMHfGr17Y/w7AoHBALzwZeYebeekiVucGSjq\n" \
65     "T8SgLhT7zCIx+JMUPjVfYzaUhP/Iu7Lkma6IzWm9nW6Drpy5pUpMzwUWDCLfzU9q\n" \
66     "eseFIl337kEn9wLn+t5OpgAyCqYmlftxbqvdrrBN9uvnrJjWvqk/8wsDrw9JxAGc\n" \
67     "fjeD4nBXUqvYWLXApoR9mZoGKedmoH9pFig4zlO9ig8YITnKYuQ0k6SD0b8agJHc\n" \
68     "Ir0YSUDnRGgpjvFBGbeOCe+FGbohk/EpItJc3IAh5740lwKBwAdXd2DjokSmYKn7\n" \
69     "oeqKxofz6+yVlLW5YuOiuX78sWlVp87xPolgi84vSEnkKM/Xsc8+goc6YstpRVa+\n" \
70     "W+mImoA9YW1dF5HkLeWhTAf9AlgoAEIhbeIfTgBv6KNZSv7RDrDPBBxtXx/vAfSg\n" \
71     "x0ldwk0scZsVYXLKd67yzfV7KdGUdaX4N/xYgfZm/9gCG3+q8NN2KxVHQ5F71BOE\n" \
72     "JeABOaGo9WvnU+DNMIDZjHJMUWVw4MHz/a/UArDf/2CxaPVBNQKBwASg6j4ohSTk\n" \
73     "J7aE6RQ3OBmmDDpixcoCJt9u9SjHVYMlbs5CEJGVSczk0SG3y8P1lOWNDSRnMksZ\n" \
74     "xWnHdP/ogcuYMuvK7UACNAF0zNddtzOhzcpNmejFj+WCHYY/UmPr2/Kf6t7Cxk2K\n" \
75     "3cZ4tqWsiTmBT8Bknmah7L5DrhS+ZBJliDeFAA8fZHdMH0Xjr4UBp9kF90EMTdW1\n" \
76     "Xr5uz7ZrMsYpYQI7mmyqV9SSjUg4iBXwVSoag1iDJ1K8Qg/L7Semgg==\n" \
77     "-----END RSA PRIVATE KEY-----\n"
78 
79 /*
80  * This loads the private key we defined earlier
81  */
82 static gnutls_x509_privkey_t test_tls_load_key(void)
83 {
84     gnutls_x509_privkey_t key;
85     const gnutls_datum_t data = { (unsigned char *)PRIVATE_KEY,
86                                   strlen(PRIVATE_KEY) };
87     int err;
88 
89     err = gnutls_x509_privkey_init(&key);
90     if (err < 0) {
91         g_critical("Failed to init key %s", gnutls_strerror(err));
92         abort();
93     }
94 
95     err = gnutls_x509_privkey_import(key, &data,
96                                      GNUTLS_X509_FMT_PEM);
97     if (err < 0) {
98         if (err != GNUTLS_E_BASE64_UNEXPECTED_HEADER_ERROR &&
99             err != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
100             g_critical("Failed to import key %s", gnutls_strerror(err));
101             abort();
102         }
103 
104         err = gnutls_x509_privkey_import_pkcs8(
105             key, &data, GNUTLS_X509_FMT_PEM, NULL, 0);
106         if (err < 0) {
107             g_critical("Failed to import PKCS8 key %s", gnutls_strerror(err));
108             abort();
109         }
110     }
111 
112     return key;
113 }
114 
115 
116 void test_tls_init(const char *keyfile)
117 {
118     qcrypto_init(&error_abort);
119 
120     if (asn1_array2tree(pkix_asn1_tab, &pkix_asn1, NULL) != ASN1_SUCCESS) {
121         abort();
122     }
123 
124     privkey = test_tls_load_key();
125     if (!g_file_set_contents(keyfile, PRIVATE_KEY, -1, NULL)) {
126         abort();
127     }
128 }
129 
130 
131 void test_tls_cleanup(const char *keyfile)
132 {
133     asn1_delete_structure(&pkix_asn1);
134     unlink(keyfile);
135 }
136 
137 /*
138  * Turns an ASN1 object into a DER encoded byte array
139  */
140 static void test_tls_der_encode(asn1_node src,
141                                 const char *src_name,
142                                 gnutls_datum_t *res)
143 {
144   int size;
145   char *data = NULL;
146 
147   size = 0;
148   asn1_der_coding(src, src_name, NULL, &size, NULL);
149 
150   data = g_new0(char, size);
151 
152   asn1_der_coding(src, src_name, data, &size, NULL);
153 
154   res->data = (unsigned char *)data;
155   res->size = size;
156 }
157 
158 
159 static void
160 test_tls_get_ipaddr(const char *addrstr,
161                     char **data,
162                     int *datalen)
163 {
164     struct addrinfo *res;
165     struct addrinfo hints;
166 
167     memset(&hints, 0, sizeof(hints));
168     hints.ai_flags = AI_NUMERICHOST;
169     g_assert(getaddrinfo(addrstr, NULL, &hints, &res) == 0);
170 
171     *datalen = res->ai_addrlen;
172     *data = g_new(char, *datalen);
173     memcpy(*data, res->ai_addr, *datalen);
174     freeaddrinfo(res);
175 }
176 
177 /*
178  * This is a fairly lame x509 certificate generator.
179  *
180  * Do not copy/use this code for generating real certificates
181  * since it leaves out many things that you would want in
182  * certificates for real world usage.
183  *
184  * This is good enough only for doing tests of the QEMU
185  * TLS certificate code
186  */
187 void
188 test_tls_generate_cert(QCryptoTLSTestCertReq *req,
189                        gnutls_x509_crt_t ca)
190 {
191     gnutls_x509_crt_t crt;
192     int err;
193     static char buffer[1024 * 1024];
194     size_t size = sizeof(buffer);
195     char serial[5] = { 1, 2, 3, 4, 0 };
196     gnutls_datum_t der;
197     time_t start = time(NULL) + (60 * 60 * req->start_offset);
198     time_t expire = time(NULL) + (60 * 60 * (req->expire_offset
199                                              ? req->expire_offset : 24));
200 
201     /*
202      * Prepare our new certificate object
203      */
204     err = gnutls_x509_crt_init(&crt);
205     if (err < 0) {
206         g_critical("Failed to initialize certificate %s", gnutls_strerror(err));
207         abort();
208     }
209     err = gnutls_x509_crt_set_key(crt, privkey);
210     if (err < 0) {
211         g_critical("Failed to set certificate key %s", gnutls_strerror(err));
212         abort();
213     }
214 
215     /*
216      * A v3 certificate is required in order to be able
217      * set any of the basic constraints, key purpose and
218      * key usage data
219      */
220     gnutls_x509_crt_set_version(crt, 3);
221 
222     if (req->country) {
223         err = gnutls_x509_crt_set_dn_by_oid(
224             crt, GNUTLS_OID_X520_COUNTRY_NAME, 0,
225             req->country, strlen(req->country));
226         if (err < 0) {
227             g_critical("Failed to set certificate country name %s",
228                        gnutls_strerror(err));
229             abort();
230         }
231     }
232     if (req->cn) {
233         err = gnutls_x509_crt_set_dn_by_oid(
234             crt, GNUTLS_OID_X520_COMMON_NAME, 0,
235             req->cn, strlen(req->cn));
236         if (err < 0) {
237             g_critical("Failed to set certificate common name %s",
238                        gnutls_strerror(err));
239             abort();
240         }
241     }
242 
243     /*
244      * Setup the subject altnames, which are used
245      * for hostname checks in live sessions
246      */
247     if (req->altname1) {
248         err = gnutls_x509_crt_set_subject_alt_name(
249             crt, GNUTLS_SAN_DNSNAME,
250             req->altname1,
251             strlen(req->altname1),
252             GNUTLS_FSAN_APPEND);
253         if (err < 0) {
254             g_critical("Failed to set certificate alt name %s",
255                        gnutls_strerror(err));
256             abort();
257         }
258     }
259     if (req->altname2) {
260         err = gnutls_x509_crt_set_subject_alt_name(
261             crt, GNUTLS_SAN_DNSNAME,
262             req->altname2,
263             strlen(req->altname2),
264             GNUTLS_FSAN_APPEND);
265         if (err < 0) {
266             g_critical("Failed to set certificate %s alt name",
267                        gnutls_strerror(err));
268             abort();
269         }
270     }
271 
272     /*
273      * IP address need to be put into the cert in their
274      * raw byte form, not strings, hence this is a little
275      * more complicated
276      */
277     if (req->ipaddr1) {
278         char *data;
279         int len;
280 
281         test_tls_get_ipaddr(req->ipaddr1, &data, &len);
282 
283         err = gnutls_x509_crt_set_subject_alt_name(
284             crt, GNUTLS_SAN_IPADDRESS,
285             data, len, GNUTLS_FSAN_APPEND);
286         if (err < 0) {
287             g_critical("Failed to set certificate alt name %s",
288                        gnutls_strerror(err));
289             abort();
290         }
291         g_free(data);
292     }
293     if (req->ipaddr2) {
294         char *data;
295         int len;
296 
297         test_tls_get_ipaddr(req->ipaddr2, &data, &len);
298 
299         err = gnutls_x509_crt_set_subject_alt_name(
300             crt, GNUTLS_SAN_IPADDRESS,
301             data, len, GNUTLS_FSAN_APPEND);
302         if (err < 0) {
303             g_critical("Failed to set certificate alt name %s",
304                        gnutls_strerror(err));
305             abort();
306         }
307         g_free(data);
308     }
309 
310 
311     /*
312      * Basic constraints are used to decide if the cert
313      * is for a CA or not. We can't use the convenient
314      * gnutls API for setting this, since it hardcodes
315      * the 'critical' field which we want control over
316      */
317     if (req->basicConstraintsEnable) {
318         asn1_node ext = NULL;
319 
320         asn1_create_element(pkix_asn1, "PKIX1.BasicConstraints", &ext);
321         asn1_write_value(ext, "cA",
322                          req->basicConstraintsIsCA ? "TRUE" : "FALSE", 1);
323         asn1_write_value(ext, "pathLenConstraint", NULL, 0);
324         test_tls_der_encode(ext, "", &der);
325         err = gnutls_x509_crt_set_extension_by_oid(
326             crt, "2.5.29.19",
327             der.data, der.size,
328             req->basicConstraintsCritical);
329         if (err < 0) {
330             g_critical("Failed to set certificate basic constraints %s",
331                        gnutls_strerror(err));
332             g_free(der.data);
333             abort();
334         }
335         asn1_delete_structure(&ext);
336         g_free(der.data);
337     }
338 
339     /*
340      * Next up the key usage extension. Again we can't
341      * use the gnutls API since it hardcodes the extension
342      * to be 'critical'
343      */
344     if (req->keyUsageEnable) {
345         asn1_node ext = NULL;
346         char str[2];
347 
348         str[0] = req->keyUsageValue & 0xff;
349         str[1] = (req->keyUsageValue >> 8) & 0xff;
350 
351         asn1_create_element(pkix_asn1, "PKIX1.KeyUsage", &ext);
352         asn1_write_value(ext, "", str, 9);
353         test_tls_der_encode(ext, "", &der);
354         err = gnutls_x509_crt_set_extension_by_oid(
355             crt, "2.5.29.15",
356             der.data, der.size,
357             req->keyUsageCritical);
358         if (err < 0) {
359             g_critical("Failed to set certificate key usage %s",
360                        gnutls_strerror(err));
361             g_free(der.data);
362             abort();
363         }
364         asn1_delete_structure(&ext);
365         g_free(der.data);
366     }
367 
368     /*
369      * Finally the key purpose extension. This time
370      * gnutls has the opposite problem, always hardcoding
371      * it to be non-critical. So once again we have to
372      * set this the hard way building up ASN1 data ourselves
373      */
374     if (req->keyPurposeEnable) {
375         asn1_node ext = NULL;
376 
377         asn1_create_element(pkix_asn1, "PKIX1.ExtKeyUsageSyntax", &ext);
378         if (req->keyPurposeOID1) {
379             asn1_write_value(ext, "", "NEW", 1);
380             asn1_write_value(ext, "?LAST", req->keyPurposeOID1, 1);
381         }
382         if (req->keyPurposeOID2) {
383             asn1_write_value(ext, "", "NEW", 1);
384             asn1_write_value(ext, "?LAST", req->keyPurposeOID2, 1);
385         }
386         test_tls_der_encode(ext, "", &der);
387         err = gnutls_x509_crt_set_extension_by_oid(
388             crt, "2.5.29.37",
389             der.data, der.size,
390             req->keyPurposeCritical);
391         if (err < 0) {
392             g_critical("Failed to set certificate key purpose %s",
393                        gnutls_strerror(err));
394             g_free(der.data);
395             abort();
396         }
397         asn1_delete_structure(&ext);
398         g_free(der.data);
399     }
400 
401     /*
402      * Any old serial number will do, so lets pick 5
403      */
404     err = gnutls_x509_crt_set_serial(crt, serial, 5);
405     if (err < 0) {
406         g_critical("Failed to set certificate serial %s",
407                    gnutls_strerror(err));
408         abort();
409     }
410 
411     err = gnutls_x509_crt_set_activation_time(crt, start);
412     if (err < 0) {
413         g_critical("Failed to set certificate activation %s",
414                    gnutls_strerror(err));
415         abort();
416     }
417     err = gnutls_x509_crt_set_expiration_time(crt, expire);
418     if (err < 0) {
419         g_critical("Failed to set certificate expiration %s",
420                    gnutls_strerror(err));
421         abort();
422     }
423 
424 
425     /*
426      * If no 'ca' is set then we are self signing
427      * the cert. This is done for the root CA certs
428      */
429     err = gnutls_x509_crt_sign2(crt, ca ? ca : crt, privkey,
430                                 GNUTLS_DIG_SHA256, 0);
431     if (err < 0) {
432         g_critical("Failed to sign certificate %s",
433                    gnutls_strerror(err));
434         abort();
435     }
436 
437     /*
438      * Finally write the new cert out to disk
439      */
440     err = gnutls_x509_crt_export(
441         crt, GNUTLS_X509_FMT_PEM, buffer, &size);
442     if (err < 0) {
443         g_critical("Failed to export certificate %s: %d",
444                    gnutls_strerror(err), err);
445         abort();
446     }
447 
448     if (!g_file_set_contents(req->filename, buffer, -1, NULL)) {
449         g_critical("Failed to write certificate %s",
450                    req->filename);
451         abort();
452     }
453 
454     req->crt = crt;
455 }
456 
457 
458 void test_tls_write_cert_chain(const char *filename,
459                                gnutls_x509_crt_t *certs,
460                                size_t ncerts)
461 {
462     size_t i;
463     size_t capacity = 1024, offset = 0;
464     char *buffer = g_new0(char, capacity);
465     int err;
466 
467     for (i = 0; i < ncerts; i++) {
468         size_t len = capacity - offset;
469     retry:
470         err = gnutls_x509_crt_export(certs[i], GNUTLS_X509_FMT_PEM,
471                                      buffer + offset, &len);
472         if (err < 0) {
473             if (err == GNUTLS_E_SHORT_MEMORY_BUFFER) {
474                 buffer = g_renew(char, buffer, offset + len);
475                 capacity = offset + len;
476                 goto retry;
477             }
478             g_critical("Failed to export certificate chain %s: %d",
479                        gnutls_strerror(err), err);
480             abort();
481         }
482         offset += len;
483     }
484 
485     if (!g_file_set_contents(filename, buffer, offset, NULL)) {
486         abort();
487     }
488     g_free(buffer);
489 }
490 
491 
492 void test_tls_discard_cert(QCryptoTLSTestCertReq *req)
493 {
494     if (!req->crt) {
495         return;
496     }
497 
498     gnutls_x509_crt_deinit(req->crt);
499     req->crt = NULL;
500 
501     if (getenv("QEMU_TEST_DEBUG_CERTS") == NULL) {
502         unlink(req->filename);
503     }
504 }
505