2 * Routines for PKCS#12: Personal Information Exchange packet dissection
5 * See "PKCS #12 v1.1: Personal Information Exchange Syntax":
7 * http://www.emc.com/emc-plus/rsa-labs/pkcs/files/h11301-wp-pkcs-12v1-1-personal-information-exchange-syntax.pdf
9 * Wireshark - Network traffic analyzer
10 * By Gerald Combs <gerald@wireshark.org>
11 * Copyright 1998 Gerald Combs
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version 2
16 * of the License, or (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
31 #include <epan/packet.h>
32 #include <epan/expert.h>
33 #include <epan/oids.h>
34 #include <epan/asn1.h>
35 #include <epan/prefs.h>
36 #include <epan/wmem/wmem.h>
38 #include "packet-ber.h"
39 #include "packet-pkcs12.h"
40 #include "packet-x509af.h"
41 #include "packet-x509if.h"
42 #include "packet-cms.h"
44 #ifdef HAVE_SYS_TIME_H
49 #include <wsutil/wsgcrypt.h>
52 #define PNAME "PKCS#12: Personal Information Exchange"
53 #define PSNAME "PKCS12"
54 #define PFNAME "pkcs12"
56 #define PKCS12_PBE_ARCFOUR_SHA1_OID "1.2.840.113549.1.12.1.1"
57 #define PKCS12_PBE_3DES_SHA1_OID "1.2.840.113549.1.12.1.3"
58 #define PKCS12_PBE_RC2_40_SHA1_OID "1.2.840.113549.1.12.1.6"
60 void proto_register_pkcs12(void);
61 void proto_reg_handoff_pkcs12(void);
63 /* Initialize the protocol and registered fields */
64 static int proto_pkcs12 = -1;
66 static int hf_pkcs12_X509Certificate_PDU = -1;
67 static gint ett_decrypted_pbe = -1;
69 static expert_field ei_pkcs12_octet_string_expected = EI_INIT;
72 static const char *object_identifier_id = NULL;
73 static int iteration_count = 0;
74 static tvbuff_t *salt = NULL;
75 static const char *password = NULL;
76 static gboolean try_null_password = FALSE;
78 static void dissect_AuthenticatedSafe_OCTETSTRING_PDU(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
79 static void dissect_SafeContents_OCTETSTRING_PDU(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
80 static int dissect_PrivateKeyInfo_PDU(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data);
82 #include "packet-pkcs12-hf.c"
84 /* Initialize the subtree pointers */
85 #include "packet-pkcs12-ett.c"
87 static void append_oid(proto_tree *tree, const char *oid)
89 const char *name = NULL;
91 name = oid_resolved_from_string(oid);
92 proto_item_append_text(tree, " (%s)", name ? name : oid);
98 generate_key_or_iv(unsigned int id, tvbuff_t *salt_tvb, unsigned int iter,
99 const char *pw, unsigned int req_keylen, char * keybuf)
104 gcry_mpi_t num_b1 = NULL;
106 char hash[20], buf_b[64], buf_i[128], *p;
115 salt_size = tvb_captured_length(salt_tvb);
116 salt_p = (char *)tvb_memdup(wmem_packet_scope(), salt_tvb, 0, salt_size);
128 /* Store salt and password in BUF_I */
130 for (i = 0; i < 64; i++)
131 *p++ = salt_p[i % salt_size];
134 for (i = j = 0; i < 64; i += 2)
138 if (++j > pwlen) /* Note, that we include the trailing zero */
146 err = gcry_md_open(&md, GCRY_MD_SHA1, 0);
147 if (gcry_err_code(err))
151 for (i = 0; i < 64; i++)
153 unsigned char lid = id & 0xFF;
154 gcry_md_write (md, &lid, 1);
157 gcry_md_write(md, buf_i, pw ? 128 : 64);
160 memcpy (hash, gcry_md_read (md, 0), 20);
164 for (i = 1; i < iter; i++)
165 gcry_md_hash_buffer (GCRY_MD_SHA1, hash, hash, 20);
167 for (i = 0; i < 20 && cur_keylen < req_keylen; i++)
168 keybuf[cur_keylen++] = hash[i];
170 if (cur_keylen == req_keylen)
172 gcry_mpi_release (num_b1);
173 return TRUE; /* ready */
176 /* need more bytes. */
177 for (i = 0; i < 64; i++)
178 buf_b[i] = hash[i % 20];
182 rc = gcry_mpi_scan (&num_b1, GCRYMPI_FMT_USG, buf_b, n, &n);
189 gcry_mpi_add_ui (num_b1, num_b1, 1);
191 for (i = 0; i < 128; i += 64)
196 rc = gcry_mpi_scan (&num_ij, GCRYMPI_FMT_USG, buf_i + i, n, &n);
203 gcry_mpi_add (num_ij, num_ij, num_b1);
204 gcry_mpi_clear_highbit (num_ij, 64 * 8);
208 rc = gcry_mpi_print (GCRYMPI_FMT_USG, buf_i + i, n, &n, num_ij);
214 gcry_mpi_release (num_ij);
221 void PBE_reset_parameters(void)
227 int PBE_decrypt_data(const char *object_identifier_id_param, tvbuff_t *encrypted_tvb, asn1_ctx_t *actx, proto_item *item)
229 #ifdef HAVE_LIBGCRYPT
230 const char *encryption_algorithm;
231 gcry_cipher_hd_t cipher;
240 char *clear_data = NULL;
241 tvbuff_t *clear_tvb = NULL;
242 const gchar *oidname;
246 gboolean decrypt_ok = TRUE;
248 if(((password == NULL) || (*password == '\0')) && (try_null_password == FALSE)) {
249 /* we are not configured to decrypt */
253 encryption_algorithm = x509af_get_last_algorithm_id();
255 /* these are the only encryption schemes we understand for now */
256 if(!strcmp(encryption_algorithm, PKCS12_PBE_3DES_SHA1_OID)) {
259 algo = GCRY_CIPHER_3DES;
260 mode = GCRY_CIPHER_MODE_CBC;
261 } else if(!strcmp(encryption_algorithm, PKCS12_PBE_ARCFOUR_SHA1_OID)) {
264 algo = GCRY_CIPHER_ARCFOUR;
265 mode = GCRY_CIPHER_MODE_NONE;
266 } else if(!strcmp(encryption_algorithm, PKCS12_PBE_RC2_40_SHA1_OID)) {
269 algo = GCRY_CIPHER_RFC2268_40;
270 mode = GCRY_CIPHER_MODE_CBC;
272 /* we don't know how to decrypt this */
274 proto_item_append_text(item, " [Unsupported encryption algorithm]");
278 if((iteration_count == 0) || (salt == NULL)) {
279 proto_item_append_text(item, " [Insufficient parameters]");
283 /* allocate buffers */
284 key = (char *)wmem_alloc(wmem_packet_scope(), keylen);
286 if(!generate_key_or_iv(1 /*LEY */, salt, iteration_count, password, keylen, key))
291 iv = (char *)wmem_alloc(wmem_packet_scope(), ivlen);
293 if(!generate_key_or_iv(2 /* IV */, salt, iteration_count, password, ivlen, iv))
297 /* now try an internal function */
298 err = gcry_cipher_open(&cipher, algo, mode, 0);
299 if (gcry_err_code (err))
302 err = gcry_cipher_setkey (cipher, key, keylen);
303 if (gcry_err_code (err)) {
304 gcry_cipher_close (cipher);
309 err = gcry_cipher_setiv (cipher, iv, ivlen);
310 if (gcry_err_code (err)) {
311 gcry_cipher_close (cipher);
316 datalen = tvb_captured_length(encrypted_tvb);
317 clear_data = (char *)g_malloc(datalen);
319 err = gcry_cipher_decrypt (cipher, clear_data, datalen, (char *)tvb_memdup(wmem_packet_scope(), encrypted_tvb, 0, datalen), datalen);
320 if (gcry_err_code (err)) {
322 proto_item_append_text(item, " [Failed to decrypt with password preference]");
324 gcry_cipher_close (cipher);
329 gcry_cipher_close (cipher);
331 /* We don't know if we have successfully decrypted the data or not so we:
332 a) check the trailing bytes
333 b) see if we start with a sequence or a set (is this too constraining?
336 /* first the trailing bytes */
337 byte = clear_data[datalen-1];
341 for(i = (int)byte; i > 0 ; i--) {
342 if(clear_data[datalen - i] != byte) {
348 /* XXX: is this a failure? */
351 /* we assume the result is ASN.1 - check it is a SET or SEQUENCE */
352 byte = clear_data[0];
353 if((byte != 0x30) && (byte != 0x31)) { /* do we need more here? OCTET STRING? */
359 proto_item_append_text(item, " [Failed to decrypt with supplied password]");
364 proto_item_append_text(item, " [Decrypted successfully]");
366 tree = proto_item_add_subtree(item, ett_decrypted_pbe);
368 /* OK - so now clear_data contains the decrypted data */
370 clear_tvb = tvb_new_child_real_data(encrypted_tvb,(const guint8 *)clear_data, datalen, datalen);
371 tvb_set_free_cb(clear_tvb, g_free);
373 name = g_string_new("");
374 oidname = oid_resolved_from_string(object_identifier_id_param);
375 g_string_printf(name, "Decrypted %s", oidname ? oidname : object_identifier_id_param);
377 /* add it as a new source */
378 add_new_data_source(actx->pinfo, clear_tvb, name->str);
380 g_string_free(name, TRUE);
382 /* now try and decode it */
383 call_ber_oid_callback(object_identifier_id_param, clear_tvb, 0, actx->pinfo, tree, NULL);
387 /* we cannot decrypt */
393 #include "packet-pkcs12-fn.c"
395 static int strip_octet_string(tvbuff_t *tvb)
403 /* PKCS#7 encodes the content as OCTET STRING, whereas CMS is just any ANY */
404 /* if we use CMS (rather than PKCS#7) - which we are - we need to strip the OCTET STRING tag */
405 /* before proceeding */
407 offset = get_ber_identifier(tvb, 0, &ber_class, &pc, &tag);
408 offset = get_ber_length(tvb, offset, &len, &ind);
410 if((ber_class == BER_CLASS_UNI) && (tag == BER_UNI_TAG_OCTETSTRING))
417 static void dissect_AuthenticatedSafe_OCTETSTRING_PDU(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
420 asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);
422 if((offset = strip_octet_string(tvb)) > 0)
423 dissect_pkcs12_AuthenticatedSafe(FALSE, tvb, offset, &asn1_ctx, tree, hf_pkcs12_AuthenticatedSafe_PDU);
425 proto_tree_add_expert(tree, pinfo, &ei_pkcs12_octet_string_expected, tvb, 0, 1);
428 static void dissect_SafeContents_OCTETSTRING_PDU(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
432 asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);
434 offset = strip_octet_string(tvb);
436 dissect_pkcs12_SafeContents(FALSE, tvb, offset, &asn1_ctx, tree, hf_pkcs12_SafeContents_PDU);
439 static void dissect_X509Certificate_OCTETSTRING_PDU(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
443 asn1_ctx_init(&asn1_ctx, ASN1_ENC_BER, TRUE, pinfo);
445 if((offset = strip_octet_string(tvb)) > 0)
446 dissect_x509af_Certificate(FALSE, tvb, offset, &asn1_ctx, tree, hf_pkcs12_X509Certificate_PDU);
448 proto_tree_add_expert(tree, pinfo, &ei_pkcs12_octet_string_expected, tvb, 0, 1);
451 /*--- proto_register_pkcs12 ----------------------------------------------*/
452 void proto_register_pkcs12(void) {
455 static hf_register_info hf[] = {
456 { &hf_pkcs12_X509Certificate_PDU,
457 { "X509Certificate", "pkcs12.X509Certificate",
458 FT_NONE, BASE_NONE, NULL, 0,
459 "pkcs12.X509Certificate", HFILL }},
460 #include "packet-pkcs12-hfarr.c"
463 /* List of subtrees */
464 static gint *ett[] = {
466 #include "packet-pkcs12-ettarr.c"
468 static ei_register_info ei[] = {
469 { &ei_pkcs12_octet_string_expected, { "pkcs12.octet_string_expected", PI_PROTOCOL, PI_WARN, "BER Error: OCTET STRING expected", EXPFILL }},
472 module_t *pkcs12_module;
473 expert_module_t* expert_pkcs12;
475 /* Register protocol */
476 proto_pkcs12 = proto_register_protocol(PNAME, PSNAME, PFNAME);
478 /* Register fields and subtrees */
479 proto_register_field_array(proto_pkcs12, hf, array_length(hf));
480 proto_register_subtree_array(ett, array_length(ett));
481 expert_pkcs12 = expert_register_protocol(proto_pkcs12);
482 expert_register_field_array(expert_pkcs12, ei, array_length(ei));
484 /* Register preferences */
485 pkcs12_module = prefs_register_protocol(proto_pkcs12, NULL);
487 prefs_register_string_preference(pkcs12_module, "password",
488 "Password to decrypt the file with",
489 "The password to used to decrypt the encrypted elements within"
490 " the PKCS#12 file", &password);
492 prefs_register_bool_preference(pkcs12_module, "try_null_password",
493 "Try to decrypt with a empty password",
494 "Whether to try and decrypt the encrypted data within the"
495 " PKCS#12 with a NULL password", &try_null_password);
497 new_register_ber_syntax_dissector("PKCS#12", proto_pkcs12, dissect_PFX_PDU);
498 register_ber_oid_syntax(".p12", NULL, "PKCS#12");
499 register_ber_oid_syntax(".pfx", NULL, "PKCS#12");
503 /*--- proto_reg_handoff_pkcs12 -------------------------------------------*/
504 void proto_reg_handoff_pkcs12(void) {
505 #include "packet-pkcs12-dis-tab.c"
507 register_ber_oid_dissector("1.2.840.113549.1.9.22.1", dissect_X509Certificate_OCTETSTRING_PDU, proto_pkcs12, "x509Certificate");