xref: /freebsd/crypto/heimdal/lib/hx509/ks_file.c (revision aa772005)
1 /*
2  * Copyright (c) 2005 - 2007 Kungliga Tekniska Högskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "hx_locl.h"
35 
36 typedef enum { USE_PEM, USE_DER } outformat;
37 
38 struct ks_file {
39     hx509_certs certs;
40     char *fn;
41     outformat format;
42 };
43 
44 /*
45  *
46  */
47 
48 static int
49 parse_certificate(hx509_context context, const char *fn,
50 		  struct hx509_collector *c,
51 		  const hx509_pem_header *headers,
52 		  const void *data, size_t len,
53 		  const AlgorithmIdentifier *ai)
54 {
55     hx509_cert cert;
56     int ret;
57 
58     ret = hx509_cert_init_data(context, data, len, &cert);
59     if (ret)
60 	return ret;
61 
62     ret = _hx509_collector_certs_add(context, c, cert);
63     hx509_cert_free(cert);
64     return ret;
65 }
66 
67 static int
68 try_decrypt(hx509_context context,
69 	    struct hx509_collector *collector,
70 	    const AlgorithmIdentifier *alg,
71 	    const EVP_CIPHER *c,
72 	    const void *ivdata,
73 	    const void *password,
74 	    size_t passwordlen,
75 	    const void *cipher,
76 	    size_t len)
77 {
78     heim_octet_string clear;
79     size_t keylen;
80     void *key;
81     int ret;
82 
83     keylen = EVP_CIPHER_key_length(c);
84 
85     key = malloc(keylen);
86     if (key == NULL) {
87 	hx509_clear_error_string(context);
88 	return ENOMEM;
89     }
90 
91     ret = EVP_BytesToKey(c, EVP_md5(), ivdata,
92 			 password, passwordlen,
93 			 1, key, NULL);
94     if (ret <= 0) {
95 	hx509_set_error_string(context, 0, HX509_CRYPTO_INTERNAL_ERROR,
96 			       "Failed to do string2key for private key");
97 	return HX509_CRYPTO_INTERNAL_ERROR;
98     }
99 
100     clear.data = malloc(len);
101     if (clear.data == NULL) {
102 	hx509_set_error_string(context, 0, ENOMEM,
103 			       "Out of memory to decrypt for private key");
104 	ret = ENOMEM;
105 	goto out;
106     }
107     clear.length = len;
108 
109     {
110 	EVP_CIPHER_CTX ctx;
111 	EVP_CIPHER_CTX_init(&ctx);
112 	EVP_CipherInit_ex(&ctx, c, NULL, key, ivdata, 0);
113 	EVP_Cipher(&ctx, clear.data, cipher, len);
114 	EVP_CIPHER_CTX_cleanup(&ctx);
115     }
116 
117     ret = _hx509_collector_private_key_add(context,
118 					   collector,
119 					   alg,
120 					   NULL,
121 					   &clear,
122 					   NULL);
123 
124     memset(clear.data, 0, clear.length);
125     free(clear.data);
126 out:
127     memset(key, 0, keylen);
128     free(key);
129     return ret;
130 }
131 
132 static int
133 parse_pkcs8_private_key(hx509_context context, const char *fn,
134 			struct hx509_collector *c,
135 			const hx509_pem_header *headers,
136 			const void *data, size_t length,
137 			const AlgorithmIdentifier *ai)
138 {
139     PKCS8PrivateKeyInfo ki;
140     heim_octet_string keydata;
141 
142     int ret;
143 
144     ret = decode_PKCS8PrivateKeyInfo(data, length, &ki, NULL);
145     if (ret)
146 	return ret;
147 
148     keydata.data = rk_UNCONST(data);
149     keydata.length = length;
150 
151     ret = _hx509_collector_private_key_add(context,
152 					   c,
153 					   &ki.privateKeyAlgorithm,
154 					   NULL,
155 					   &ki.privateKey,
156 					   &keydata);
157     free_PKCS8PrivateKeyInfo(&ki);
158     return ret;
159 }
160 
161 static int
162 parse_pem_private_key(hx509_context context, const char *fn,
163 		      struct hx509_collector *c,
164 		      const hx509_pem_header *headers,
165 		      const void *data, size_t len,
166 		      const AlgorithmIdentifier *ai)
167 {
168     int ret = 0;
169     const char *enc;
170 
171     enc = hx509_pem_find_header(headers, "Proc-Type");
172     if (enc) {
173 	const char *dek;
174 	char *type, *iv;
175 	ssize_t ssize, size;
176 	void *ivdata;
177 	const EVP_CIPHER *cipher;
178 	const struct _hx509_password *pw;
179 	hx509_lock lock;
180 	int decrypted = 0;
181 	size_t i;
182 
183 	lock = _hx509_collector_get_lock(c);
184 	if (lock == NULL) {
185 	    hx509_set_error_string(context, 0, HX509_ALG_NOT_SUPP,
186 				   "Failed to get password for "
187 				   "password protected file %s", fn);
188 	    return HX509_ALG_NOT_SUPP;
189 	}
190 
191 	if (strcmp(enc, "4,ENCRYPTED") != 0) {
192 	    hx509_set_error_string(context, 0, HX509_PARSING_KEY_FAILED,
193 				   "Private key encrypted in unknown method %s "
194 				   "in file",
195 				   enc, fn);
196 	    hx509_clear_error_string(context);
197 	    return HX509_PARSING_KEY_FAILED;
198 	}
199 
200 	dek = hx509_pem_find_header(headers, "DEK-Info");
201 	if (dek == NULL) {
202 	    hx509_set_error_string(context, 0, HX509_PARSING_KEY_FAILED,
203 				   "Encrypted private key missing DEK-Info");
204 	    return HX509_PARSING_KEY_FAILED;
205 	}
206 
207 	type = strdup(dek);
208 	if (type == NULL) {
209 	    hx509_clear_error_string(context);
210 	    return ENOMEM;
211 	}
212 
213 	iv = strchr(type, ',');
214 	if (iv == NULL) {
215 	    free(type);
216 	    hx509_set_error_string(context, 0, HX509_PARSING_KEY_FAILED,
217 				   "IV missing");
218 	    return HX509_PARSING_KEY_FAILED;
219 	}
220 
221 	*iv++ = '\0';
222 
223 	size = strlen(iv);
224 	ivdata = malloc(size);
225 	if (ivdata == NULL) {
226 	    hx509_clear_error_string(context);
227 	    free(type);
228 	    return ENOMEM;
229 	}
230 
231 	cipher = EVP_get_cipherbyname(type);
232 	if (cipher == NULL) {
233 	    free(ivdata);
234 	    hx509_set_error_string(context, 0, HX509_ALG_NOT_SUPP,
235 				   "Private key encrypted with "
236 				   "unsupported cipher: %s",
237 				   type);
238 	    free(type);
239 	    return HX509_ALG_NOT_SUPP;
240 	}
241 
242 #define PKCS5_SALT_LEN 8
243 
244 	ssize = hex_decode(iv, ivdata, size);
245 	free(type);
246 	type = NULL;
247 	iv = NULL;
248 
249 	if (ssize < 0 || ssize < PKCS5_SALT_LEN || ssize < EVP_CIPHER_iv_length(cipher)) {
250 	    free(ivdata);
251 	    hx509_set_error_string(context, 0, HX509_PARSING_KEY_FAILED,
252 				   "Salt have wrong length in "
253 				   "private key file");
254 	    return HX509_PARSING_KEY_FAILED;
255 	}
256 
257 	pw = _hx509_lock_get_passwords(lock);
258 	if (pw != NULL) {
259 	    const void *password;
260 	    size_t passwordlen;
261 
262 	    for (i = 0; i < pw->len; i++) {
263 		password = pw->val[i];
264 		passwordlen = strlen(password);
265 
266 		ret = try_decrypt(context, c, ai, cipher, ivdata,
267 				  password, passwordlen, data, len);
268 		if (ret == 0) {
269 		    decrypted = 1;
270 		    break;
271 		}
272 	    }
273 	}
274 	if (!decrypted) {
275 	    hx509_prompt prompt;
276 	    char password[128];
277 
278 	    memset(&prompt, 0, sizeof(prompt));
279 
280 	    prompt.prompt = "Password for keyfile: ";
281 	    prompt.type = HX509_PROMPT_TYPE_PASSWORD;
282 	    prompt.reply.data = password;
283 	    prompt.reply.length = sizeof(password);
284 
285 	    ret = hx509_lock_prompt(lock, &prompt);
286 	    if (ret == 0)
287 		ret = try_decrypt(context, c, ai, cipher, ivdata, password,
288 				  strlen(password), data, len);
289 	    /* XXX add password to lock password collection ? */
290 	    memset(password, 0, sizeof(password));
291 	}
292 	free(ivdata);
293 
294     } else {
295 	heim_octet_string keydata;
296 
297 	keydata.data = rk_UNCONST(data);
298 	keydata.length = len;
299 
300 	ret = _hx509_collector_private_key_add(context, c, ai, NULL,
301 					       &keydata, NULL);
302     }
303 
304     return ret;
305 }
306 
307 
308 struct pem_formats {
309     const char *name;
310     int (*func)(hx509_context, const char *, struct hx509_collector *,
311 		const hx509_pem_header *, const void *, size_t,
312 		const AlgorithmIdentifier *);
313     const AlgorithmIdentifier *(*ai)(void);
314 } formats[] = {
315     { "CERTIFICATE", parse_certificate, NULL },
316     { "PRIVATE KEY", parse_pkcs8_private_key, NULL },
317     { "RSA PRIVATE KEY", parse_pem_private_key, hx509_signature_rsa },
318     { "EC PRIVATE KEY", parse_pem_private_key, hx509_signature_ecPublicKey }
319 };
320 
321 
322 struct pem_ctx {
323     int flags;
324     struct hx509_collector *c;
325 };
326 
327 static int
328 pem_func(hx509_context context, const char *type,
329 	 const hx509_pem_header *header,
330 	 const void *data, size_t len, void *ctx)
331 {
332     struct pem_ctx *pem_ctx = (struct pem_ctx*)ctx;
333     int ret = 0;
334     size_t j;
335 
336     for (j = 0; j < sizeof(formats)/sizeof(formats[0]); j++) {
337 	const char *q = formats[j].name;
338 	if (strcasecmp(type, q) == 0) {
339 	    const AlgorithmIdentifier *ai = NULL;
340 	    if (formats[j].ai != NULL)
341 		ai = (*formats[j].ai)();
342 
343 	    ret = (*formats[j].func)(context, NULL, pem_ctx->c,
344 				     header, data, len, ai);
345 	    if (ret && (pem_ctx->flags & HX509_CERTS_UNPROTECT_ALL)) {
346 		hx509_set_error_string(context, HX509_ERROR_APPEND, ret,
347 				       "Failed parseing PEM format %s", type);
348 		return ret;
349 	    }
350 	    break;
351 	}
352     }
353     if (j == sizeof(formats)/sizeof(formats[0])) {
354 	ret = HX509_UNSUPPORTED_OPERATION;
355 	hx509_set_error_string(context, 0, ret,
356 			       "Found no matching PEM format for %s", type);
357 	return ret;
358     }
359     return 0;
360 }
361 
362 /*
363  *
364  */
365 
366 static int
367 file_init_common(hx509_context context,
368 		 hx509_certs certs, void **data, int flags,
369 		 const char *residue, hx509_lock lock, outformat format)
370 {
371     char *p, *pnext;
372     struct ks_file *ksf = NULL;
373     hx509_private_key *keys = NULL;
374     int ret;
375     struct pem_ctx pem_ctx;
376 
377     pem_ctx.flags = flags;
378     pem_ctx.c = NULL;
379 
380     *data = NULL;
381 
382     if (lock == NULL)
383 	lock = _hx509_empty_lock;
384 
385     ksf = calloc(1, sizeof(*ksf));
386     if (ksf == NULL) {
387 	hx509_clear_error_string(context);
388 	return ENOMEM;
389     }
390     ksf->format = format;
391 
392     ksf->fn = strdup(residue);
393     if (ksf->fn == NULL) {
394 	hx509_clear_error_string(context);
395 	ret = ENOMEM;
396 	goto out;
397     }
398 
399     /*
400      * XXX this is broken, the function should parse the file before
401      * overwriting it
402      */
403 
404     if (flags & HX509_CERTS_CREATE) {
405 	ret = hx509_certs_init(context, "MEMORY:ks-file-create",
406 			       0, lock, &ksf->certs);
407 	if (ret)
408 	    goto out;
409 	*data = ksf;
410 	return 0;
411     }
412 
413     ret = _hx509_collector_alloc(context, lock, &pem_ctx.c);
414     if (ret)
415 	goto out;
416 
417     for (p = ksf->fn; p != NULL; p = pnext) {
418 	FILE *f;
419 
420 	pnext = strchr(p, ',');
421 	if (pnext)
422 	    *pnext++ = '\0';
423 
424 
425 	if ((f = fopen(p, "r")) == NULL) {
426 	    ret = ENOENT;
427 	    hx509_set_error_string(context, 0, ret,
428 				   "Failed to open PEM file \"%s\": %s",
429 				   p, strerror(errno));
430 	    goto out;
431 	}
432 	rk_cloexec_file(f);
433 
434 	ret = hx509_pem_read(context, f, pem_func, &pem_ctx);
435 	fclose(f);
436 	if (ret != 0 && ret != HX509_PARSING_KEY_FAILED)
437 	    goto out;
438 	else if (ret == HX509_PARSING_KEY_FAILED) {
439 	    size_t length;
440 	    void *ptr;
441 	    size_t i;
442 
443 	    ret = rk_undumpdata(p, &ptr, &length);
444 	    if (ret) {
445 		hx509_clear_error_string(context);
446 		goto out;
447 	    }
448 
449 	    for (i = 0; i < sizeof(formats)/sizeof(formats[0]); i++) {
450 		const AlgorithmIdentifier *ai = NULL;
451 		if (formats[i].ai != NULL)
452 		    ai = (*formats[i].ai)();
453 
454 		ret = (*formats[i].func)(context, p, pem_ctx.c, NULL, ptr, length, ai);
455 		if (ret == 0)
456 		    break;
457 	    }
458 	    rk_xfree(ptr);
459 	    if (ret) {
460 		hx509_clear_error_string(context);
461 		goto out;
462 	    }
463 	}
464     }
465 
466     ret = _hx509_collector_collect_certs(context, pem_ctx.c, &ksf->certs);
467     if (ret)
468 	goto out;
469 
470     ret = _hx509_collector_collect_private_keys(context, pem_ctx.c, &keys);
471     if (ret == 0) {
472 	int i;
473 
474 	for (i = 0; keys[i]; i++)
475 	    _hx509_certs_keys_add(context, ksf->certs, keys[i]);
476 	_hx509_certs_keys_free(context, keys);
477     }
478 
479 out:
480     if (ret == 0)
481 	*data = ksf;
482     else {
483 	if (ksf->fn)
484 	    free(ksf->fn);
485 	free(ksf);
486     }
487     if (pem_ctx.c)
488 	_hx509_collector_free(pem_ctx.c);
489 
490     return ret;
491 }
492 
493 static int
494 file_init_pem(hx509_context context,
495 	      hx509_certs certs, void **data, int flags,
496 	      const char *residue, hx509_lock lock)
497 {
498     return file_init_common(context, certs, data, flags, residue, lock, USE_PEM);
499 }
500 
501 static int
502 file_init_der(hx509_context context,
503 	      hx509_certs certs, void **data, int flags,
504 	      const char *residue, hx509_lock lock)
505 {
506     return file_init_common(context, certs, data, flags, residue, lock, USE_DER);
507 }
508 
509 static int
510 file_free(hx509_certs certs, void *data)
511 {
512     struct ks_file *ksf = data;
513     hx509_certs_free(&ksf->certs);
514     free(ksf->fn);
515     free(ksf);
516     return 0;
517 }
518 
519 struct store_ctx {
520     FILE *f;
521     outformat format;
522 };
523 
524 static int
525 store_func(hx509_context context, void *ctx, hx509_cert c)
526 {
527     struct store_ctx *sc = ctx;
528     heim_octet_string data;
529     int ret;
530 
531     ret = hx509_cert_binary(context, c, &data);
532     if (ret)
533 	return ret;
534 
535     switch (sc->format) {
536     case USE_DER:
537 	fwrite(data.data, data.length, 1, sc->f);
538 	free(data.data);
539 	break;
540     case USE_PEM:
541 	hx509_pem_write(context, "CERTIFICATE", NULL, sc->f,
542 			data.data, data.length);
543 	free(data.data);
544 	if (_hx509_cert_private_key_exportable(c)) {
545 	    hx509_private_key key = _hx509_cert_private_key(c);
546 	    ret = _hx509_private_key_export(context, key,
547 					    HX509_KEY_FORMAT_DER, &data);
548 	    if (ret)
549 		break;
550 	    hx509_pem_write(context, _hx509_private_pem_name(key), NULL, sc->f,
551 			    data.data, data.length);
552 	    free(data.data);
553 	}
554 	break;
555     }
556 
557     return 0;
558 }
559 
560 static int
561 file_store(hx509_context context,
562 	   hx509_certs certs, void *data, int flags, hx509_lock lock)
563 {
564     struct ks_file *ksf = data;
565     struct store_ctx sc;
566     int ret;
567 
568     sc.f = fopen(ksf->fn, "w");
569     if (sc.f == NULL) {
570 	hx509_set_error_string(context, 0, ENOENT,
571 			       "Failed to open file %s for writing");
572 	return ENOENT;
573     }
574     rk_cloexec_file(sc.f);
575     sc.format = ksf->format;
576 
577     ret = hx509_certs_iter_f(context, ksf->certs, store_func, &sc);
578     fclose(sc.f);
579     return ret;
580 }
581 
582 static int
583 file_add(hx509_context context, hx509_certs certs, void *data, hx509_cert c)
584 {
585     struct ks_file *ksf = data;
586     return hx509_certs_add(context, ksf->certs, c);
587 }
588 
589 static int
590 file_iter_start(hx509_context context,
591 		hx509_certs certs, void *data, void **cursor)
592 {
593     struct ks_file *ksf = data;
594     return hx509_certs_start_seq(context, ksf->certs, cursor);
595 }
596 
597 static int
598 file_iter(hx509_context context,
599 	  hx509_certs certs, void *data, void *iter, hx509_cert *cert)
600 {
601     struct ks_file *ksf = data;
602     return hx509_certs_next_cert(context, ksf->certs, iter, cert);
603 }
604 
605 static int
606 file_iter_end(hx509_context context,
607 	      hx509_certs certs,
608 	      void *data,
609 	      void *cursor)
610 {
611     struct ks_file *ksf = data;
612     return hx509_certs_end_seq(context, ksf->certs, cursor);
613 }
614 
615 static int
616 file_getkeys(hx509_context context,
617 	     hx509_certs certs,
618 	     void *data,
619 	     hx509_private_key **keys)
620 {
621     struct ks_file *ksf = data;
622     return _hx509_certs_keys_get(context, ksf->certs, keys);
623 }
624 
625 static int
626 file_addkey(hx509_context context,
627 	     hx509_certs certs,
628 	     void *data,
629 	     hx509_private_key key)
630 {
631     struct ks_file *ksf = data;
632     return _hx509_certs_keys_add(context, ksf->certs, key);
633 }
634 
635 static struct hx509_keyset_ops keyset_file = {
636     "FILE",
637     0,
638     file_init_pem,
639     file_store,
640     file_free,
641     file_add,
642     NULL,
643     file_iter_start,
644     file_iter,
645     file_iter_end,
646     NULL,
647     file_getkeys,
648     file_addkey
649 };
650 
651 static struct hx509_keyset_ops keyset_pemfile = {
652     "PEM-FILE",
653     0,
654     file_init_pem,
655     file_store,
656     file_free,
657     file_add,
658     NULL,
659     file_iter_start,
660     file_iter,
661     file_iter_end,
662     NULL,
663     file_getkeys,
664     file_addkey
665 };
666 
667 static struct hx509_keyset_ops keyset_derfile = {
668     "DER-FILE",
669     0,
670     file_init_der,
671     file_store,
672     file_free,
673     file_add,
674     NULL,
675     file_iter_start,
676     file_iter,
677     file_iter_end,
678     NULL,
679     file_getkeys,
680     file_addkey
681 };
682 
683 
684 void
685 _hx509_ks_file_register(hx509_context context)
686 {
687     _hx509_ks_register(context, &keyset_file);
688     _hx509_ks_register(context, &keyset_pemfile);
689     _hx509_ks_register(context, &keyset_derfile);
690 }
691