Bug Summary

File:builds/wireshark/wireshark/epan/dissectors/packet-knxip_decrypt.c
Warning:line 809, column 3
Opened stream never closed. Potential resource leak

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name packet-knxip_decrypt.c -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -fno-delete-null-pointer-checks -mframe-pointer=all -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -ffloat16-excess-precision=fast -fbfloat16-excess-precision=fast -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/builds/wireshark/wireshark/build -fcoverage-compilation-dir=/builds/wireshark/wireshark/build -resource-dir /usr/lib/llvm-21/lib/clang/21 -isystem /usr/include/glib-2.0 -isystem /usr/lib/x86_64-linux-gnu/glib-2.0/include -isystem /builds/wireshark/wireshark/epan/dissectors -isystem /builds/wireshark/wireshark/build/epan/dissectors -isystem /usr/include/mit-krb5 -isystem /usr/include/libxml2 -isystem /builds/wireshark/wireshark/epan -D G_DISABLE_DEPRECATED -D G_DISABLE_SINGLE_INCLUDES -D WS_BUILD_DLL -D WS_DEBUG -D WS_DEBUG_UTF_8 -I /builds/wireshark/wireshark/build -I /builds/wireshark/wireshark -I /builds/wireshark/wireshark/include -D _GLIBCXX_ASSERTIONS -internal-isystem /usr/lib/llvm-21/lib/clang/21/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/14/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/builds/wireshark/wireshark/= -fmacro-prefix-map=/builds/wireshark/wireshark/build/= -fmacro-prefix-map=../= -Wno-format-nonliteral -std=gnu11 -ferror-limit 19 -fvisibility=hidden -fwrapv -fwrapv-pointer -fstrict-flex-arrays=3 -stack-protector 2 -fstack-clash-protection -fcf-protection=full -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fexceptions -fcolor-diagnostics -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /builds/wireshark/wireshark/sbout/2026-03-15-100342-3641-1 -x c /builds/wireshark/wireshark/epan/dissectors/packet-knxip_decrypt.c
1/* packet-knxip_decrypt.c
2 * Decryption keys and decryption functions for KNX/IP Dissector
3 * Copyright 2018, ise GmbH <[email protected]>
4 *
5 * Wireshark - Network traffic analyzer
6 * By Gerald Combs <[email protected]>
7 * Copyright 1998 Gerald Combs
8 *
9 * SPDX-License-Identifier: GPL-2.0-or-later
10 */
11
12#include "config.h"
13#define WS_LOG_DOMAIN"packet-knxip" "packet-knxip"
14
15#include <wsutil/file_util.h>
16#include <epan/proto.h>
17#include "packet-knxip_decrypt.h"
18#include <epan/wmem_scopes.h>
19#include <wsutil/wsgcrypt.h>
20#include <wsutil/strtoi.h>
21#include <wsutil/wslog.h>
22#include <wsutil/inet_addr.h>
23#include <libxml/tree.h>
24#include <libxml/parser.h>
25#include <libxml/xpath.h>
26
27#define TEXT_BUFFER_SIZE128 128
28
29#define IPA_SIZE4 4 // = size of IPv4 address
30
31#define BASE64_KNX_KEY_LENGTH24 24 // = length of base64 encoded KNX key
32
33struct knx_keyring_mca_keys* knx_keyring_mca_keys;
34struct knx_keyring_ga_keys* knx_keyring_ga_keys;
35struct knx_keyring_ga_senders* knx_keyring_ga_senders;
36struct knx_keyring_ia_keys* knx_keyring_ia_keys;
37struct knx_keyring_ia_seqs* knx_keyring_ia_seqs;
38
39// Encrypt 16-byte block via AES
40static bool_Bool encrypt_block( const uint8_t key[ KNX_KEY_LENGTH16 ], const uint8_t plain[ KNX_KEY_LENGTH16 ], uint8_t p_crypt[ KNX_KEY_LENGTH16 ] )
41{
42 gcry_cipher_hd_t cryptor = NULL((void*)0);
43 gcry_error_t err;
44 err = gcry_cipher_open( &cryptor, GCRY_CIPHER_AES128GCRY_CIPHER_AES, GCRY_CIPHER_MODE_CBC, 0 );
45 if (err != 0) {
46 ws_debug("failed to open AES128 cipher handle: %s/%s", gcry_strsource(err), gcry_strerror(err))do { if (1) { ws_log_full("packet-knxip", LOG_LEVEL_DEBUG, "epan/dissectors/packet-knxip_decrypt.c"
, 46, __func__, "failed to open AES128 cipher handle: %s/%s",
gcry_strsource(err), gcry_strerror(err)); } } while (0);
47 return false0;
48 }
49 err = gcry_cipher_setkey( cryptor, key, KNX_KEY_LENGTH16 );
50 if (err != 0) {
51 ws_debug("failed to set AES128 cipher key: %s/%s", gcry_strsource(err), gcry_strerror(err))do { if (1) { ws_log_full("packet-knxip", LOG_LEVEL_DEBUG, "epan/dissectors/packet-knxip_decrypt.c"
, 51, __func__, "failed to set AES128 cipher key: %s/%s", gcry_strsource
(err), gcry_strerror(err)); } } while (0);
52 gcry_cipher_close( cryptor );
53 return false0;
54 }
55 err = gcry_cipher_encrypt( cryptor, p_crypt, KNX_KEY_LENGTH16, plain, KNX_KEY_LENGTH16 );
56 if (err != 0) {
57 ws_debug("failed to encrypt AES128: %s/%s", gcry_strsource(err), gcry_strerror(err))do { if (1) { ws_log_full("packet-knxip", LOG_LEVEL_DEBUG, "epan/dissectors/packet-knxip_decrypt.c"
, 57, __func__, "failed to encrypt AES128: %s/%s", gcry_strsource
(err), gcry_strerror(err)); } } while (0);
58 gcry_cipher_close( cryptor );
59 return false0;
60 }
61 gcry_cipher_close( cryptor );
62 return true1;
63}
64
65// Create B_0 for CBC-MAC
66static void build_b0( uint8_t p_result[ KNX_KEY_LENGTH16 ], const uint8_t* nonce, uint8_t nonce_length )
67{
68 DISSECTOR_ASSERT( nonce_length <= KNX_KEY_LENGTH )((void) ((nonce_length <= 16) ? (void)0 : (proto_report_dissector_bug
("%s:%u: failed assertion \"%s\"", "epan/dissectors/packet-knxip_decrypt.c"
, 68, "nonce_length <= 16"))));
69 if( nonce_length ) memcpy( p_result, nonce, nonce_length );
70 memset( p_result + nonce_length, 0, KNX_KEY_LENGTH16 - nonce_length );
71}
72
73// Create Ctr_0 for CCM encryption/decryption
74static void build_ctr0( uint8_t p_result[ KNX_KEY_LENGTH16 ], const uint8_t* nonce, uint8_t nonce_length )
75{
76 build_b0( p_result, nonce, nonce_length );
77 p_result[ KNX_KEY_LENGTH16 - 2 ] = 0xFF;
78}
79
80// Calculate MAC for KNX IP Security or KNX Data Security
81void knx_ccm_calc_cbc_mac(uint8_t p_mac[ KNX_KEY_LENGTH16 ], const uint8_t key[ KNX_KEY_LENGTH16 ],
82 const uint8_t* a_bytes, int a_length, const uint8_t* p_bytes, int p_length,
83 const uint8_t b_0[ KNX_KEY_LENGTH16 ] )
84{
85 uint8_t plain[ KNX_KEY_LENGTH16 ];
86 uint8_t b_pos;
87
88 // Add B_0
89 memcpy( plain, b_0, KNX_KEY_LENGTH16 );
90 if (!encrypt_block( key, plain, p_mac )) {
91 memset(p_mac, 0, KNX_KEY_LENGTH16);
92 return;
93 }
94
95 // Add a_length
96 plain[ 0 ] = (uint8_t) ((a_length >> 8) ^ p_mac[ 0 ]);
97 plain[ 1 ] = (uint8_t) ((a_length & 0xFF) ^ p_mac[ 1 ]);
98 b_pos = 2;
99
100 // Add a_bytes directly followed by p_bytes
101 while( a_length || p_length )
102 {
103 while( a_length && b_pos < KNX_KEY_LENGTH16 )
104 {
105 plain[ b_pos ] = *a_bytes++ ^ p_mac[ b_pos ];
106 --a_length;
107 ++b_pos;
108 }
109
110 while( p_length && b_pos < KNX_KEY_LENGTH16 )
111 {
112 plain[ b_pos ] = *p_bytes++ ^ p_mac[ b_pos ];
113 --p_length;
114 ++b_pos;
115 }
116
117 while( b_pos < KNX_KEY_LENGTH16 )
118 {
119 plain[ b_pos ] = p_mac[ b_pos ];
120 ++b_pos;
121 }
122
123 if (!encrypt_block( key, plain, p_mac )) {
124 memset(p_mac, 0, KNX_KEY_LENGTH16);
125 return;
126 }
127
128 b_pos = 0;
129 }
130}
131
132// Calculate MAC for KNX IP Security, using 6-byte Sequence ID
133void knxip_ccm_calc_cbc_mac( uint8_t p_mac[ KNX_KEY_LENGTH16 ], const uint8_t key[ KNX_KEY_LENGTH16 ],
134 const uint8_t* a_bytes, int a_length, const uint8_t* p_bytes, int p_length,
135 const uint8_t* nonce, uint8_t nonce_length )
136{
137 uint8_t b_0[ KNX_KEY_LENGTH16 ];
138 build_b0( b_0, nonce, nonce_length );
139 b_0[ KNX_KEY_LENGTH16 - 2 ] = (uint8_t) (p_length >> 8);
140 b_0[ KNX_KEY_LENGTH16 - 1 ] = (uint8_t) (p_length & 0xFF);
141 knx_ccm_calc_cbc_mac( p_mac, key, a_bytes, a_length, p_bytes, p_length, b_0 );
142}
143
144// Encrypt for KNX IP Security or KNX Data Security
145uint8_t* knx_ccm_encrypt(wmem_allocator_t* scope, uint8_t* p_result, const uint8_t key[ KNX_KEY_LENGTH16 ], const uint8_t* p_bytes, int p_length,
146 const uint8_t* mac, uint8_t mac_length, const uint8_t ctr_0[ KNX_KEY_LENGTH16 ], uint8_t s0_bytes_used_for_mac )
147{
148 if( p_length >= 0 && !(p_length && !p_bytes) )
149 {
150 // NB: mac_length = 16 (for IP Security), or 4 (for Data Security)
151
152 uint8_t* result = p_result ? p_result : (uint8_t*) wmem_alloc(scope, p_length + mac_length );
153
154 uint8_t* dest = result;
155
156 uint8_t ctr[ KNX_KEY_LENGTH16 ];
157 uint8_t mask[ KNX_KEY_LENGTH16 ];
158 uint8_t mask_0[ KNX_KEY_LENGTH16 ];
159 uint8_t b_pos;
160
161 // Encrypt ctr_0 for mac
162 memcpy( ctr, ctr_0, KNX_KEY_LENGTH16 );
163 if (!encrypt_block( key, ctr, mask_0 )) {
164 if (!p_result) wmem_free(scope, result);
165 return NULL((void*)0);
166 }
167
168 // Encrypt p_bytes with rest of S_0, only if mac_length < 16.
169 b_pos = s0_bytes_used_for_mac;
170 while (p_length && b_pos < KNX_KEY_LENGTH16 )
171 {
172 *dest++ = mask_0[b_pos++] ^ *p_bytes++;
173 --p_length;
174 }
175
176 // Encrypt p_bytes
177 while( p_length )
178 {
179 // Increment and encrypt ctr
180 ++ctr[ KNX_KEY_LENGTH16 - 1 ];
181 if (!encrypt_block( key, ctr, mask )) {
182 if (!p_result) wmem_free(scope, result);
183 return NULL((void*)0);
184 }
185
186 // Encrypt input block via encrypted ctr
187 b_pos = 0;
188 while( p_length && b_pos < KNX_KEY_LENGTH16 )
189 {
190 *dest++ = mask[ b_pos++] ^ *p_bytes++;
191 --p_length;
192 }
193 }
194
195 if( mac )
196 {
197 if( mac_length > KNX_KEY_LENGTH16 )
198 {
199 mac_length = KNX_KEY_LENGTH16;
200 }
201
202 // Encrypt and append mac
203 b_pos = 0;
204 while( mac_length )
205 {
206 *dest++ = mask_0[ b_pos++] ^ *mac++;
207 --mac_length;
208 }
209 }
210
211 return result;
212 }
213
214 return NULL((void*)0);
215}
216
217// Encrypt for KNX IP Security (with 16-byte MAC and Nonce based on 6-byte Sequence ID)
218uint8_t* knxip_ccm_encrypt(wmem_allocator_t* scope, uint8_t* p_result, const uint8_t key[ KNX_KEY_LENGTH16 ], const uint8_t* p_bytes, int p_length,
219 const uint8_t mac[KNX_KEY_LENGTH16], const uint8_t* nonce, uint8_t nonce_length )
220{
221 uint8_t ctr_0[ KNX_KEY_LENGTH16 ];
222 build_ctr0( ctr_0, nonce, nonce_length );
223 return knx_ccm_encrypt(scope, p_result, key, p_bytes, p_length, mac, KNX_KEY_LENGTH16, ctr_0, KNX_KEY_LENGTH16 );
224}
225
226// Decrypt for KNX-IP Security (with 16-byte MAC and Nonce based on 6-byte Sequence ID)
227uint8_t* knxip_ccm_decrypt(wmem_allocator_t* scope, uint8_t* p_result, const uint8_t key[ KNX_KEY_LENGTH16 ], const uint8_t* crypt, int crypt_length,
228 const uint8_t* nonce, uint8_t nonce_length )
229{
230 int p_length = crypt_length - KNX_KEY_LENGTH16;
231 uint8_t ctr_0[ KNX_KEY_LENGTH16 ];
232 build_ctr0( ctr_0, nonce, nonce_length );
233 return knx_ccm_encrypt(scope, p_result, key, crypt, p_length, crypt + p_length, KNX_KEY_LENGTH16, ctr_0, KNX_KEY_LENGTH16 );
234}
235
236static void fprintf_hex( FILE* f, const uint8_t* data, uint8_t length )
237{
238 for( ; length; --length ) fprintf( f, " %02X", *data++ );
239 fputc( '\n', f );
240}
241
242static void clear_keyring_data( void )
243{
244 while( knx_keyring_mca_keys )
245 {
246 struct knx_keyring_mca_keys* mca_key = knx_keyring_mca_keys;
247 knx_keyring_mca_keys = mca_key->next;
248 wmem_free( wmem_epan_scope(), mca_key );
249 }
250
251 while( knx_keyring_ga_keys )
252 {
253 struct knx_keyring_ga_keys* ga_key = knx_keyring_ga_keys;
254 knx_keyring_ga_keys = ga_key->next;
255 wmem_free( wmem_epan_scope(), ga_key );
256 }
257
258 while( knx_keyring_ga_senders )
259 {
260 struct knx_keyring_ga_senders* ga_sender = knx_keyring_ga_senders;
261 knx_keyring_ga_senders = ga_sender->next;
262 wmem_free( wmem_epan_scope(), ga_sender );
263 }
264
265 while( knx_keyring_ia_keys )
266 {
267 struct knx_keyring_ia_keys* ia_key = knx_keyring_ia_keys;
268 knx_keyring_ia_keys = ia_key->next;
269 wmem_free( wmem_epan_scope(), ia_key );
270 }
271
272 while( knx_keyring_ia_seqs )
273 {
274 struct knx_keyring_ia_seqs* ia_seq = knx_keyring_ia_seqs;
275 knx_keyring_ia_seqs = ia_seq->next;
276 wmem_free( wmem_epan_scope(), ia_seq );
277 }
278}
279
280// Read IP address
281static void read_ip_addr( uint8_t result[ 4 ], const char* text )
282{
283 ws_in4_addr value = 0;
284 if( ws_inet_pton4( text, &value ) )
285 memcpy( result, &value, 4 );
286 else
287 memset( result, 0, 4 );
288}
289
290// Read KNX group address
291static uint16_t read_ga( const char* text )
292{
293 unsigned a[ 3 ];
294 int n = sscanf( text, "%u/%u/%u", a, a + 1, a + 2 );
295 return
296 (n == 1) ? (uint16_t) a[ 0 ] :
297 (n == 2) ? (uint16_t) ((a[ 0 ] << 11) | a[ 1 ]) :
298 (n == 3) ? (uint16_t) ((a[ 0 ] << 11) | (a[ 1 ] << 8) | a[ 2 ]) :
299 0;
300}
301
302// Read KNX individual address
303static uint16_t read_ia( const char* text )
304{
305 unsigned a[ 3 ];
306 int n = sscanf( text, "%u.%u.%u", a, a + 1, a + 2 );
307 return
308 (n == 1) ? (uint16_t) a[ 0 ] :
309 (n == 2) ? (uint16_t) ((a[ 0 ] << 8) | a[ 1 ]) :
310 (n == 3) ? (uint16_t) ((a[ 0 ] << 12) | (a[ 1 ] << 8) | a[ 2 ]) :
311 0;
312}
313
314// Read 6-byte sequence number from decimal representation
315static uint64_t read_seq( const char* text )
316{
317 uint64_t result;
318 return ws_strtou64( text, NULL((void*)0), &result ) ? result : 0;
319}
320
321// Decrypt key
322static void decrypt_key( uint8_t key[] _U___attribute__((unused)), uint8_t password_hash[] _U___attribute__((unused)), uint8_t created_hash[] _U___attribute__((unused)) )
323{
324 // TODO: decrypt as AES128-CBC(key, password_hash, created_hash)
325}
326
327// Decode and decrypt key
328static void decode_and_decrypt_key( uint8_t key[ BASE64_KNX_KEY_LENGTH24 + 1 ], const char* text, uint8_t password_hash[], uint8_t created_hash[] )
329{
330 size_t out_len;
331 snprintf( (char*) key, BASE64_KNX_KEY_LENGTH24 + 1, "%s", text );
332 g_base64_decode_inplace( (char*) key, &out_len );
333 decrypt_key( key, password_hash, created_hash );
334}
335
336// Add MCA <-> key association
337static void add_mca_key( const uint8_t mca[ IPA_SIZE4 ], const char* text, uint8_t password_hash[], uint8_t created_hash[], FILE* f2 )
338{
339 int text_length = (int) strlen( text );
340
341 if( text_length == BASE64_KNX_KEY_LENGTH24 )
342 {
343 uint8_t key[ BASE64_KNX_KEY_LENGTH24 + 1 ];
344 struct knx_keyring_mca_keys** mca_keys_next;
345 struct knx_keyring_mca_keys* mca_key;
346
347 decode_and_decrypt_key( key, text, password_hash, created_hash );
348
349 mca_keys_next = &knx_keyring_mca_keys;
350
351 while( (mca_key = *mca_keys_next) != NULL((void*)0) )
352 {
353 if( memcmp( mca_key->mca, mca, IPA_SIZE4 ) == 0 )
354 {
355 if( memcmp( mca_key->key, key, KNX_KEY_LENGTH16 ) == 0 )
356 {
357 return;
358 }
359 }
360
361 mca_keys_next = &mca_key->next;
362 }
363
364 if( f2 )
365 {
366 fprintf( f2, "MCA %u.%u.%u.%u key", mca[ 0 ], mca[ 1 ], mca[ 2 ], mca[ 3 ] );
367 fprintf_hex( f2, key, KNX_KEY_LENGTH16 );
368 }
369
370 mca_key = wmem_new(wmem_epan_scope(), struct knx_keyring_mca_keys)((struct knx_keyring_mca_keys*)wmem_alloc((wmem_epan_scope())
, sizeof(struct knx_keyring_mca_keys)));
371
372 if( mca_key )
373 {
374 mca_key->next = NULL((void*)0);
375 memcpy( mca_key->mca, mca, IPA_SIZE4 );
376 memcpy( mca_key->key, key, KNX_KEY_LENGTH16 );
377
378 *mca_keys_next = mca_key;
379 }
380 }
381}
382
383// Add GA <-> key association
384static void add_ga_key( uint16_t ga, const char* text, uint8_t password_hash[], uint8_t created_hash[], FILE* f2 )
385{
386 int text_length = (int) strlen( text );
387
388 if( text_length == BASE64_KNX_KEY_LENGTH24 )
389 {
390 uint8_t key[ BASE64_KNX_KEY_LENGTH24 + 1 ];
391 struct knx_keyring_ga_keys** ga_keys_next;
392 struct knx_keyring_ga_keys* ga_key;
393
394 decode_and_decrypt_key( key, text, password_hash, created_hash );
395
396 ga_keys_next = &knx_keyring_ga_keys;
397
398 while( (ga_key = *ga_keys_next) != NULL((void*)0) )
399 {
400 if( ga_key->ga == ga )
401 {
402 if( memcmp( ga_key->key, key, KNX_KEY_LENGTH16 ) == 0 )
403 {
404 return;
405 }
406 }
407
408 ga_keys_next = &ga_key->next;
409 }
410
411 if( f2 )
412 {
413 fprintf( f2, "GA %d/%d/%d key", (ga >> 11) & 0x1F, (ga >> 8) & 0x7, ga & 0xFF );
414 fprintf_hex( f2, key, KNX_KEY_LENGTH16 );
415 }
416
417 ga_key = wmem_new(wmem_epan_scope(), struct knx_keyring_ga_keys)((struct knx_keyring_ga_keys*)wmem_alloc((wmem_epan_scope()),
sizeof(struct knx_keyring_ga_keys)));
418
419 if( ga_key )
420 {
421 ga_key->next = NULL((void*)0);
422 ga_key->ga = ga;
423 memcpy( ga_key->key, key, KNX_KEY_LENGTH16 );
424
425 *ga_keys_next = ga_key;
426 }
427 }
428}
429
430// Add GA <-> sender association
431static void add_ga_sender( uint16_t ga, const char* text, FILE* f2 )
432{
433 uint16_t ia = read_ia( text );
434 struct knx_keyring_ga_senders** ga_senders_next = &knx_keyring_ga_senders;
435 struct knx_keyring_ga_senders* ga_sender;
436
437 while( (ga_sender = *ga_senders_next) != NULL((void*)0) )
438 {
439 if( ga_sender->ga == ga )
440 {
441 if( ga_sender->ia == ia )
442 {
443 return;
444 }
445 }
446
447 ga_senders_next = &ga_sender->next;
448 }
449
450 if( f2 )
451 {
452 fprintf( f2, "GA %d/%d/%d sender %d.%d.%d\n", (ga >> 11) & 0x1F, (ga >> 8) & 0x7, ga & 0xFF, (ia >> 12) & 0xF, (ia >> 8) & 0xF, ia & 0xFF );
453 }
454
455 ga_sender = wmem_new(wmem_epan_scope(), struct knx_keyring_ga_senders)((struct knx_keyring_ga_senders*)wmem_alloc((wmem_epan_scope(
)), sizeof(struct knx_keyring_ga_senders)));
456
457 if( ga_sender )
458 {
459 ga_sender->next = NULL((void*)0);
460 ga_sender->ga = ga;
461 ga_sender->ia = ia;
462
463 *ga_senders_next = ga_sender;
464 }
465}
466
467// Add IA <-> key association
468static void add_ia_key( uint16_t ia, const char* text, uint8_t password_hash[], uint8_t created_hash[], FILE* f2 )
469{
470 int text_length = (int) strlen( text );
471
472 if( text_length == BASE64_KNX_KEY_LENGTH24 )
473 {
474 uint8_t key[ BASE64_KNX_KEY_LENGTH24 + 1 ];
475 struct knx_keyring_ia_keys** ia_keys_next;
476 struct knx_keyring_ia_keys* ia_key;
477
478 decode_and_decrypt_key( key, text, password_hash, created_hash );
479
480 ia_keys_next = &knx_keyring_ia_keys;
481
482 while( (ia_key = *ia_keys_next) != NULL((void*)0) )
483 {
484 if( ia_key->ia == ia )
485 {
486 if( memcmp( ia_key->key, key, KNX_KEY_LENGTH16 ) == 0 )
487 {
488 return;
489 }
490 }
491
492 ia_keys_next = &ia_key->next;
493 }
494
495 if( f2 )
496 {
497 fprintf( f2, "IA %d.%d.%d key", (ia >> 12) & 0xF, (ia >> 8) & 0xF, ia & 0xFF );
498 fprintf_hex( f2, key, KNX_KEY_LENGTH16 );
499 }
500
501 ia_key = wmem_new(wmem_epan_scope(), struct knx_keyring_ia_keys)((struct knx_keyring_ia_keys*)wmem_alloc((wmem_epan_scope()),
sizeof(struct knx_keyring_ia_keys)));
502
503 if( ia_key )
504 {
505 ia_key->next = NULL((void*)0);
506 ia_key->ia = ia;
507 memcpy( ia_key->key, key, KNX_KEY_LENGTH16 );
508
509 *ia_keys_next = ia_key;
510 }
511 }
512}
513
514// Add IA <-> sequence number association
515static void add_ia_seq( uint16_t ia, const char* text, FILE* f2 )
516{
517 uint64_t seq = read_seq( text );
518
519 struct knx_keyring_ia_seqs** ia_seqs_next = &knx_keyring_ia_seqs;
520 struct knx_keyring_ia_seqs* ia_seq;
521
522 while( (ia_seq = *ia_seqs_next) != NULL((void*)0) )
523 {
524 if( ia_seq->ia == ia )
525 {
526 if( ia_seq->seq == seq )
527 {
528 return;
529 }
530 }
531
532 ia_seqs_next = &ia_seq->next;
533 }
534
535 if( f2 )
536 {
537 fprintf( f2, "IA %u.%u.%u SeqNr %" PRIu64"l" "u" "\n", (ia >> 12) & 0xF, (ia >> 8) & 0xF, ia & 0xFF, seq );
538 }
539
540 ia_seq = wmem_new(wmem_epan_scope(), struct knx_keyring_ia_seqs)((struct knx_keyring_ia_seqs*)wmem_alloc((wmem_epan_scope()),
sizeof(struct knx_keyring_ia_seqs)));
541
542 if( ia_seq )
543 {
544 ia_seq->next = NULL((void*)0);
545 ia_seq->ia = ia;
546 ia_seq->seq = seq;
547
548 *ia_seqs_next = ia_seq;
549 }
550}
551
552// Calculate PBKDF2(HMAC-SHA256, password, "1.keyring.ets.knx.org", 65536, 128)
553static void make_password_hash( uint8_t password_hash[] _U___attribute__((unused)), const char* password _U___attribute__((unused)) )
554{
555 // TODO: password_hash = PBKDF2(HMAC-SHA256, password, "1.keyring.ets.knx.org", 65536, 128)
556}
557
558// Calculate MSB128(SHA256(created))
559static void make_created_hash( uint8_t created_hash[] _U___attribute__((unused)), const char* created _U___attribute__((unused)) )
560{
561 // TODO: created_hash = MSB128(SHA256(created))
562}
563
564static void read_knx_keyring_xml_backbone_element(xmlNodePtr backbone, uint8_t password_hash[], uint8_t created_hash[], FILE* f2)
565{
566 bool_Bool address_valid = false0;
567 uint8_t multicast_address[IPA_SIZE4] = { 0 };
568
569 /* Parse out the attributes of the Backbone element */
570 for (xmlAttrPtr attr = backbone->properties; attr; attr = attr->next)
571 {
572 if (xmlStrcmp(attr->name, (const xmlChar*)"MulticastAddress") == 0)
573 {
574 xmlChar* str_address = xmlNodeListGetString(backbone->doc, attr->children, 1);
575 if (str_address != NULL((void*)0))
576 {
577 read_ip_addr(multicast_address, (const char*)str_address);
578 address_valid = true1;
579 xmlFree(str_address);
580 }
581 }
582 else if (xmlStrcmp(attr->name, (const xmlChar*)"Key") == 0)
583 {
584 if (address_valid)
585 {
586 xmlChar* str_key = xmlNodeListGetString(backbone->doc, attr->children, 1);
587 if (str_key != NULL((void*)0))
588 {
589 add_mca_key(multicast_address, (const char*)str_key, password_hash, created_hash, f2);
590 xmlFree(str_key);
591 }
592 }
593 }
594 }
595
596}
597
598static void read_knx_keyring_xml_group_element(xmlNodePtr group, uint8_t password_hash[], uint8_t created_hash[], FILE* f2)
599{
600 bool_Bool address_valid = false0;
601 uint16_t addr = 0;
602
603 /* Parse out the attributes of the Group element */
604 for (xmlAttrPtr attr = group->properties; attr; attr = attr->next)
605 {
606 if (xmlStrcmp(attr->name, (const xmlChar*)"Address") == 0)
607 {
608 xmlChar* str_address = xmlNodeListGetString(group->doc, attr->children, 1);
609 if (str_address != NULL((void*)0))
610 {
611 addr = read_ga((const char*)str_address);
612 address_valid = true1;
613 xmlFree(str_address);
614 }
615 }
616 else if (xmlStrcmp(attr->name, (const xmlChar*)"Key") == 0)
617 {
618 if (address_valid)
619 {
620 xmlChar* str_key = xmlNodeListGetString(group->doc, attr->children, 1);
621 add_ga_key(addr, (const char*)str_key, password_hash, created_hash, f2);
622 xmlFree(str_key);
623 }
624 }
625 else if (xmlStrcmp(attr->name, (const xmlChar*)"Senders") == 0)
626 {
627 if (address_valid)
628 {
629 xmlChar* str_senders = xmlNodeListGetString(group->doc, attr->children, 1);
630 if (str_senders != NULL((void*)0))
631 {
632 // Add senders given by space separated list of KNX IAs
633 static const char delim[] = " ,";
634 const char* token = strtok((char*)str_senders, delim);
635 while (token)
636 {
637 add_ga_sender(addr, token, f2);
638 token = strtok(NULL((void*)0), delim);
639 }
640 xmlFree(str_senders);
641 }
642 }
643 }
644 }
645
646}
647
648static void read_knx_keyring_xml_device_element(xmlNodePtr device, uint8_t password_hash[], uint8_t created_hash[], FILE* f2)
649{
650 bool_Bool address_valid = false0;
651 uint16_t addr = 0;
652
653 /* Parse out the attributes of the Device element */
654 for (xmlAttrPtr attr = device->properties; attr; attr = attr->next)
655 {
656 if (xmlStrcmp(attr->name, (const xmlChar*)"IndividualAddress") == 0)
657 {
658 xmlChar* str_address = xmlNodeListGetString(device->doc, attr->children, 1);
659 if (str_address != NULL((void*)0))
660 {
661 addr = read_ia((const char*)str_address);
662 address_valid = true1;
663 xmlFree(str_address);
664 }
665 }
666 else if (xmlStrcmp(attr->name, (const xmlChar*)"ToolKey") == 0)
667 {
668 if (address_valid)
669 {
670 xmlChar* str_key = xmlNodeListGetString(device->doc, attr->children, 1);
671 if (str_key != NULL((void*)0))
672 {
673 add_ia_key(addr, (const char*)str_key, password_hash, created_hash, f2);
674 xmlFree(str_key);
675 }
676 }
677 }
678 else if (xmlStrcmp(attr->name, (const xmlChar*)"SequenceNumber") == 0)
679 {
680 if (address_valid)
681 {
682 xmlChar* str_seq = xmlNodeListGetString(device->doc, attr->children, 1);
683 if (str_seq != NULL((void*)0))
684 {
685 add_ia_seq(addr, (const char*)str_seq, f2);
686 xmlFree(str_seq);
687 }
688 }
689 }
690 }
691}
692
693// Read KNX security key info from keyring XML file.
694//
695// An example keyring XML file is
696// "test/keys/knx_keyring.xml".
697//
698// Corresponding test is
699// suite_decryption.case_decrypt_knxip.test_knxip_keyring_xml_import
700//
701// Resulting decoded and decrypted 16-byte keys with context info are optionally written to a "key info" text file.
702// This may be useful, as these keys are not directly available from the keyring XML file .
703void read_knx_keyring_xml_file(const char* key_file, const char* password, const char* key_info_file)
704{
705 xmlDocPtr doc;
706 xmlNodePtr root_element = NULL((void*)0);
707 xmlNodePtr key_ring = NULL((void*)0);
708 uint8_t password_hash[KNX_KEY_LENGTH16] = { 0 };
709 uint8_t created_hash[KNX_KEY_LENGTH16] = {0};
710
711 // Clear old keyring data
712 clear_keyring_data();
713
714 doc = xmlReadFile(key_file, NULL((void*)0), 0);
715 if (doc == NULL((void*)0))
1
Assuming 'doc' is not equal to NULL
→
2
←
Taking false branch
→
716 return;
717
718 root_element = xmlDocGetRootElement(doc);
719 if (root_element == NULL((void*)0))
3
←
Assuming 'root_element' is not equal to NULL
→
4
←
Taking false branch
→
720 {
721 xmlFreeDoc(doc);
722 return;
723 }
724
725 /* Find the Keyring element */
726 if (xmlStrcmp(root_element->name, (const xmlChar*)"Keyring") == 0)
5
←
Assuming the condition is true
→
6
←
Taking true branch
→
727 {
728 key_ring = root_element;
729 }
730 else
731 {
732 for (xmlNodePtr cur = root_element->children; cur != NULL((void*)0); cur = cur->next)
733 {
734 if (cur->type == XML_ELEMENT_NODE && xmlStrcmp(cur->name, (const xmlChar*)"Keyring") == 0)
735 {
736 key_ring = cur;
737 break;
738 }
739 }
740 }
741
742 if (key_ring
6.1
'key_ring' is not equal to NULL
 == NULL((void*)0)) {
743 xmlFreeDoc(doc);
744 return;
745 }
746
747 // Optionally write extracted data to key info file
748 FILE* f2 = (!key_info_file || !*key_info_file) ? NULL((void*)0) :
7
←
Assuming 'key_info_file' is non-null
→
8
←
Assuming the condition is false
→
749 (strcmp( key_info_file, "-" ) == 0) ? stdoutstdout :
9
←
Assuming the condition is false
→
10
←
'?' condition is false
→
750 ws_fopenfopen( key_info_file, "w" );
11
←
Stream opened here
→
12
←
Assuming that 'fopen' is successful
→
751
752 make_password_hash(password_hash, password);
753
754 /* Parse out the attributes of the Keyring element */
755 for (xmlAttrPtr attr = key_ring->properties; attr; attr = attr->next)
13
←
Loop condition is true. Entering loop body
→
18
←
Loop condition is false. Execution continues on line 769
→
756 {
757 if (xmlStrcmp(attr->name, (const xmlChar*)"Created") == 0)
14
←
Assuming the condition is true
→
15
←
Taking true branch
→
758 {
759 xmlChar* str_created = xmlNodeListGetString(key_ring->doc, attr->children, 1);
760 if (str_created != NULL((void*)0))
16
←
Assuming 'str_created' is not equal to NULL
→
17
←
Taking true branch
→
761 {
762 make_created_hash(created_hash, (const char*)str_created);
763 xmlFree(str_created);
764 }
765 }
766 }
767
768 /* Parse out subelements of Keyring element */
769 for (xmlNodePtr cur = key_ring->children; cur != NULL((void*)0); cur = cur->next)
19
←
Assuming 'cur' is equal to NULL
→
770 {
771 if (cur->type == XML_ELEMENT_NODE && xmlStrcmp(cur->name, (const xmlChar*)"Backbone") == 0)
772 {
773 read_knx_keyring_xml_backbone_element(cur, password_hash, created_hash, f2);
774 }
775 else if (cur->type == XML_ELEMENT_NODE && xmlStrcmp(cur->name, (const xmlChar*)"Interface") == 0)
776 {
777 for (xmlNodePtr group = cur->children; group != NULL((void*)0); group = group->next)
778 {
779 if (group->type == XML_ELEMENT_NODE && xmlStrcmp(group->name, (const xmlChar*)"Group") == 0)
780 {
781 read_knx_keyring_xml_group_element(group, password_hash, created_hash, f2);
782 }
783 }
784 }
785 else if (cur->type == XML_ELEMENT_NODE && xmlStrcmp(cur->name, (const xmlChar*)"GroupAddresses") == 0)
786 {
787 for (xmlNodePtr group = cur->children; group != NULL((void*)0); group = group->next)
788 {
789 if (group->type == XML_ELEMENT_NODE && xmlStrcmp(group->name, (const xmlChar*)"Group") == 0)
790 {
791 read_knx_keyring_xml_group_element(group, password_hash, created_hash, f2);
792 }
793 }
794 }
795 else if (cur->type == XML_ELEMENT_NODE && xmlStrcmp(cur->name, (const xmlChar*)"Devices") == 0)
796 {
797 for (xmlNodePtr device = cur->children; device != NULL((void*)0); device = device->next)
798 {
799 if (device->type == XML_ELEMENT_NODE && xmlStrcmp(device->name, (const xmlChar*)"Device") == 0)
800 {
801 read_knx_keyring_xml_device_element(device, password_hash, created_hash, f2);
802 }
803 }
804 }
805 }
806
807 if (f2
19.1
'f2' is non-null
 && f2 != stdoutstdout)
20
←
Assuming 'f2' is equal to 'stdout'
→
21
←
Taking false branch
→
808 fclose(f2);
809 xmlFreeDoc(doc);
22
←
Opened stream never closed. Potential resource leak
810}
811
812/*
813 * Editor modelines - https://www.wireshark.org/tools/modelines.html
814 *
815 * Local variables:
816 * c-basic-offset: 2
817 * tab-width: 8
818 * indent-tabs-mode: nil
819 * End:
820 *
821 * vi: set shiftwidth=2 tabstop=8 expandtab:
822 * :indentSize=2:tabSize=8:noTabs=true:
823 */