1 /*
2  * Copyright (c) 2002-2022 Apple Inc. All rights reserved.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     https://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifdef __cplusplus
18 extern "C" {
19 #endif
20 
21 #include "mDNSEmbeddedAPI.h"
22 #include "DNSCommon.h"
23 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
24 #include <CommonCrypto/CommonHMAC.h>
25 #endif
26 #include "mdns_strict.h"
27 
28 // Disable certain benign warnings with Microsoft compilers
29 #if (defined(_MSC_VER))
30 // Disable "conditional expression is constant" warning for debug macros.
31 // Otherwise, this generates warnings for the perfectly natural construct "while(1)"
32 // If someone knows a variant way of writing "while(1)" that doesn't generate warning messages, please let us know
33     #pragma warning(disable:4127)
34 #endif
35 
36 
37 // ***************************************************************************
38 // MARK: - Byte Swapping Functions
39 
NToH16(mDNSu8 * bytes)40 mDNSlocal mDNSu16 NToH16(mDNSu8 * bytes)
41 {
42     return (mDNSu16)((mDNSu16)bytes[0] << 8 | (mDNSu16)bytes[1]);
43 }
44 
NToH32(mDNSu8 * bytes)45 mDNSlocal mDNSu32 NToH32(mDNSu8 * bytes)
46 {
47     return (mDNSu32)((mDNSu32) bytes[0] << 24 | (mDNSu32) bytes[1] << 16 | (mDNSu32) bytes[2] << 8 | (mDNSu32)bytes[3]);
48 }
49 
50 // ***************************************************************************
51 // MARK: - MD5 Hash Functions
52 
53 
54 /* The source for the has is derived CommonCrypto files CommonDigest.h, md32_common.h, md5_locl.h, md5_locl.h, and openssl/md5.h.
55  * The following changes have been made to the original sources:
56  *    replaced CC_LONG w/ mDNSu32
57  *    replaced CC_MD5* with MD5*
58  *    replaced CC_LONG w/ mDNSu32, removed conditional #defines from md5.h
59  *    removed extern decls for MD5_Init/Update/Final from CommonDigest.h
60  *    removed APPLE_COMMON_DIGEST specific #defines from md5_locl.h
61  *
62  * Note: machine archetecure specific conditionals from the original sources are turned off, but are left in the code
63  * to aid in platform-specific optimizations and debugging.
64  * Sources originally distributed under the following license headers:
65  * CommonDigest.h - APSL
66  *
67  * md32_Common.h
68  * ====================================================================
69  * Copyright (c) 1999-2002 The OpenSSL Project.  All rights reserved.
70  *
71  * Redistribution and use in source and binary forms, with or without
72  * modification, are permitted provided that the following conditions
73  * are met:
74  *
75  * 1. Redistributions of source code must retain the above copyright
76  *    notice, this list of conditions and the following disclaimer.
77  *
78  * 2. Redistributions in binary form must reproduce the above copyright
79  *    notice, this list of conditions and the following disclaimer in
80  *    the documentation and/or other materials provided with the
81  *    distribution.
82  *
83  * 3. All advertising materials mentioning features or use of this
84  *    software must display the following acknowledgment:
85  *    "This product includes software developed by the OpenSSL Project
86  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
87  *
88  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
89  *    endorse or promote products derived from this software without
90  *    prior written permission. For written permission, please contact
91  *    licensing@OpenSSL.org.
92  *
93  * 5. Products derived from this software may not be called "OpenSSL"
94  *    nor may "OpenSSL" appear in their names without prior written
95  *    permission of the OpenSSL Project.
96  *
97  * 6. Redistributions of any form whatsoever must retain the following
98  *    acknowledgment:
99  *    "This product includes software developed by the OpenSSL Project
100  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
101  *
102  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
103  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
104  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
105  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
106  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
107  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
108  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
109  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
110  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
111  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
112  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
113  * OF THE POSSIBILITY OF SUCH DAMAGE.
114  *
115  *
116  * md5_dgst.c, md5_locl.h
117  * ====================================================================
118  *
119  * This product includes cryptographic software written by Eric Young
120  * (eay@cryptsoft.com).  This product includes software written by Tim
121  * Hudson (tjh@cryptsoft.com).
122  *
123  * Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
124  * All rights reserved.
125  *
126  * This package is an SSL implementation written
127  * by Eric Young (eay@cryptsoft.com).
128  * The implementation was written so as to conform with Netscapes SSL.
129  *
130  * This library is free for commercial and non-commercial use as long as
131  * the following conditions are aheared to.  The following conditions
132  * apply to all code found in this distribution, be it the RC4, RSA,
133  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
134  * included with this distribution is covered by the same copyright terms
135  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
136  *
137  * Copyright remains Eric Young's, and as such any Copyright notices in
138  * the code are not to be removed.
139  * If this package is used in a product, Eric Young should be given attribution
140  * as the author of the parts of the library used.
141  * This can be in the form of a textual message at program startup or
142  * in documentation (online or textual) provided with the package.
143  *
144  * Redistribution and use in source and binary forms, with or without
145  * modification, are permitted provided that the following conditions
146  * are met:
147  * 1. Redistributions of source code must retain the copyright
148  *    notice, this list of conditions and the following disclaimer.
149  * 2. Redistributions in binary form must reproduce the above copyright
150  *    notice, this list of conditions and the following disclaimer in the
151  *    documentation and/or other materials provided with the distribution.
152  * 3. All advertising materials mentioning features or use of this software
153  *    must display the following acknowledgement:
154  *    "This product includes cryptographic software written by
155  *     Eric Young (eay@cryptsoft.com)"
156  *    The word 'cryptographic' can be left out if the rouines from the library
157  *    being used are not cryptographic related :-).
158  * 4. If you include any Windows specific code (or a derivative thereof) from
159  *    the apps directory (application code) you must include an acknowledgement:
160  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
161  *
162  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
163  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
164  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
165  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
166  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
167  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
168  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
169  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
170  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
171  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
172  * SUCH DAMAGE.
173  *
174  * The licence and distribution terms for any publically available version or
175  * derivative of this code cannot be changed.  i.e. this code cannot simply be
176  * copied and put under another distribution licence
177  * [including the GNU Public Licence.]
178  *
179  */
180 
181 //from CommonDigest.h
182 
183 
184 
185 // from openssl/md5.h
186 
187 #define MD5_CBLOCK  64
188 #define MD5_LBLOCK  (MD5_CBLOCK/4)
189 //#define MD5_DIGEST_LENGTH 16
190 
191 void MD5_Transform(MD5_CTX *c, const unsigned char *b);
192 
193 // From md5_locl.h
194 
195 #ifndef MD5_LONG_LOG2
196 #define MD5_LONG_LOG2 2 /* default to 32 bits */
197 #endif
198 
199 #ifdef MD5_ASM
200 # if defined(__i386) || defined(__i386__) || defined(_M_IX86) || defined(__INTEL__)
201 #  define md5_block_host_order md5_block_asm_host_order
202 # elif defined(__sparc) && defined(OPENSSL_SYS_ULTRASPARC)
203 void md5_block_asm_data_order_aligned (MD5_CTX *c, const mDNSu32 *p,int num);
204 #  define HASH_BLOCK_DATA_ORDER_ALIGNED md5_block_asm_data_order_aligned
205 # endif
206 #endif
207 
208 void md5_block_host_order (MD5_CTX *c, const void *p,int num);
209 void md5_block_data_order (MD5_CTX *c, const void *p,int num);
210 
211 #if defined(__i386) || defined(__i386__) || defined(_M_IX86) || defined(__INTEL__)
212 /*
213  * *_block_host_order is expected to handle aligned data while
214  * *_block_data_order - unaligned. As algorithm and host (x86)
215  * are in this case of the same "endianness" these two are
216  * otherwise indistinguishable. But normally you don't want to
217  * call the same function because unaligned access in places
218  * where alignment is expected is usually a "Bad Thing". Indeed,
219  * on RISCs you get punished with BUS ERROR signal or *severe*
220  * performance degradation. Intel CPUs are in turn perfectly
221  * capable of loading unaligned data without such drastic side
222  * effect. Yes, they say it's slower than aligned load, but no
223  * exception is generated and therefore performance degradation
224  * is *incomparable* with RISCs. What we should weight here is
225  * costs of unaligned access against costs of aligning data.
226  * According to my measurements allowing unaligned access results
227  * in ~9% performance improvement on Pentium II operating at
228  * 266MHz. I won't be surprised if the difference will be higher
229  * on faster systems:-)
230  *
231  *                                      <appro@fy.chalmers.se>
232  */
233 #define md5_block_data_order md5_block_host_order
234 #endif
235 
236 #define DATA_ORDER_IS_LITTLE_ENDIAN
237 
238 #define HASH_LONG       mDNSu32
239 #define HASH_LONG_LOG2  MD5_LONG_LOG2
240 #define HASH_CTX        MD5_CTX
241 #define HASH_CBLOCK     MD5_CBLOCK
242 #define HASH_LBLOCK     MD5_LBLOCK
243 
244 #define HASH_UPDATE     MD5_Update
245 #define HASH_TRANSFORM  MD5_Transform
246 #define HASH_FINAL      MD5_Final
247 
248 #define HASH_MAKE_STRING(c,s)   do {    \
249         unsigned long ll;       \
250         ll=(c)->A; HOST_l2c(ll,(s));    \
251         ll=(c)->B; HOST_l2c(ll,(s));    \
252         ll=(c)->C; HOST_l2c(ll,(s));    \
253         ll=(c)->D; HOST_l2c(ll,(s));    \
254 } while (0)
255 #define HASH_BLOCK_HOST_ORDER   md5_block_host_order
256 #if !defined(L_ENDIAN) || defined(md5_block_data_order)
257 #define HASH_BLOCK_DATA_ORDER   md5_block_data_order
258 /*
259  * Little-endians (Intel and Alpha) feel better without this.
260  * It looks like memcpy does better job than generic
261  * md5_block_data_order on copying-n-aligning input data.
262  * But frankly speaking I didn't expect such result on Alpha.
263  * On the other hand I've got this with egcs-1.0.2 and if
264  * program is compiled with another (better?) compiler it
265  * might turn out other way around.
266  *
267  *                                      <appro@fy.chalmers.se>
268  */
269 #endif
270 
271 
272 // from md32_common.h
273 
274 /*
275  * This is a generic 32 bit "collector" for message digest algorithms.
276  * Whenever needed it collects input character stream into chunks of
277  * 32 bit values and invokes a block function that performs actual hash
278  * calculations.
279  *
280  * Porting guide.
281  *
282  * Obligatory macros:
283  *
284  * DATA_ORDER_IS_BIG_ENDIAN or DATA_ORDER_IS_LITTLE_ENDIAN
285  *        this macro defines byte order of input stream.
286  * HASH_CBLOCK
287  *        size of a unit chunk HASH_BLOCK operates on.
288  * HASH_LONG
289  *        has to be at lest 32 bit wide, if it's wider, then
290  *        HASH_LONG_LOG2 *has to* be defined along
291  * HASH_CTX
292  *        context structure that at least contains following
293  *        members:
294  *                  typedef struct {
295  *                            ...
296  *                            HASH_LONG Nl,Nh;
297  *                            HASH_LONG data[HASH_LBLOCK];
298  *                            int                 num;
299  *                            ...
300  *                            } HASH_CTX;
301  * HASH_UPDATE
302  *        name of "Update" function, implemented here.
303  * HASH_TRANSFORM
304  *        name of "Transform" function, implemented here.
305  * HASH_FINAL
306  *        name of "Final" function, implemented here.
307  * HASH_BLOCK_HOST_ORDER
308  *        name of "block" function treating *aligned* input message
309  *        in host byte order, implemented externally.
310  * HASH_BLOCK_DATA_ORDER
311  *        name of "block" function treating *unaligned* input message
312  *        in original (data) byte order, implemented externally (it
313  *        actually is optional if data and host are of the same
314  *        "endianess").
315  * HASH_MAKE_STRING
316  *        macro convering context variables to an ASCII hash string.
317  *
318  * Optional macros:
319  *
320  * B_ENDIAN or L_ENDIAN
321  *        defines host byte-order.
322  * HASH_LONG_LOG2
323  *        defaults to 2 if not states otherwise.
324  * HASH_LBLOCK
325  *        assumed to be HASH_CBLOCK/4 if not stated otherwise.
326  * HASH_BLOCK_DATA_ORDER_ALIGNED
327  *        alternative "block" function capable of treating
328  *        aligned input message in original (data) order,
329  *        implemented externally.
330  *
331  * MD5 example:
332  *
333  *        #define DATA_ORDER_IS_LITTLE_ENDIAN
334  *
335  *        #define HASH_LONG             mDNSu32
336  *        #define HASH_LONG_LOG2        mDNSu32_LOG2
337  *        #define HASH_CTX              MD5_CTX
338  *        #define HASH_CBLOCK           MD5_CBLOCK
339  *        #define HASH_LBLOCK           MD5_LBLOCK
340  *        #define HASH_UPDATE           MD5_Update
341  *        #define HASH_TRANSFORM                  MD5_Transform
342  *        #define HASH_FINAL            MD5_Final
343  *        #define HASH_BLOCK_HOST_ORDER md5_block_host_order
344  *        #define HASH_BLOCK_DATA_ORDER md5_block_data_order
345  *
346  *                                                <appro@fy.chalmers.se>
347  */
348 
349 #if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN)
350 #error "DATA_ORDER must be defined!"
351 #endif
352 
353 #ifndef HASH_CBLOCK
354 #error "HASH_CBLOCK must be defined!"
355 #endif
356 #ifndef HASH_LONG
357 #error "HASH_LONG must be defined!"
358 #endif
359 #ifndef HASH_CTX
360 #error "HASH_CTX must be defined!"
361 #endif
362 
363 #ifndef HASH_UPDATE
364 #error "HASH_UPDATE must be defined!"
365 #endif
366 #ifndef HASH_TRANSFORM
367 #error "HASH_TRANSFORM must be defined!"
368 #endif
369 #ifndef HASH_FINAL
370 #error "HASH_FINAL must be defined!"
371 #endif
372 
373 #ifndef HASH_BLOCK_HOST_ORDER
374 #error "HASH_BLOCK_HOST_ORDER must be defined!"
375 #endif
376 
377 #if 0
378 /*
379  * Moved below as it's required only if HASH_BLOCK_DATA_ORDER_ALIGNED
380  * isn't defined.
381  */
382 #ifndef HASH_BLOCK_DATA_ORDER
383 #error "HASH_BLOCK_DATA_ORDER must be defined!"
384 #endif
385 #endif
386 
387 #ifndef HASH_LBLOCK
388 #define HASH_LBLOCK (HASH_CBLOCK/4)
389 #endif
390 
391 #ifndef HASH_LONG_LOG2
392 #define HASH_LONG_LOG2  2
393 #endif
394 
395 /*
396  * Engage compiler specific rotate intrinsic function if available.
397  */
398 #if defined(__GNUC__)
399 #pragma GCC diagnostic push
400 #pragma GCC diagnostic ignored "-Wunused-macros"
401 #endif
402 #undef ROTATE
403 #ifndef PEDANTIC
404 # if 0 /* defined(_MSC_VER) */
405 #  define ROTATE(a,n)   _lrotl(a,n)
406 # elif defined(__MWERKS__)
407 #  if defined(__POWERPC__)
408 #   define ROTATE(a,n)  (unsigned MD32_REG_T)__rlwinm((int)a,n,0,31)
409 #  elif defined(__MC68K__)
410 /* Motorola specific tweak. <appro@fy.chalmers.se> */
411 #   define ROTATE(a,n)  (n<24 ? __rol(a,n) : __ror(a,32-n))
412 #  else
413 #   define ROTATE(a,n)  __rol(a,n)
414 #  endif
415 # elif defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
416 /*
417  * Some GNU C inline assembler templates. Note that these are
418  * rotates by *constant* number of bits! But that's exactly
419  * what we need here...
420  *
421  *                  <appro@fy.chalmers.se>
422  */
423 /*
424  * LLVM is more strict about compatibility of types between input & output constraints,
425  * but we want these to be rotations of 32 bits, not 64, so we explicitly drop the
426  * most significant bytes by casting to an unsigned int.
427  */
428 #  if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)
429 #   define ROTATE(a,n)  ({ register unsigned int ret;   \
430                            asm (           \
431                                "roll %1,%0"        \
432                                : "=r" (ret)     \
433                                : "I" (n), "0" ((unsigned int)a)  \
434                                : "cc");        \
435                            ret;             \
436                          })
437 #  elif defined(__powerpc) || defined(__ppc)
438 #   define ROTATE(a,n)  ({ register unsigned int ret;   \
439                            asm (           \
440                                "rlwinm %0,%1,%2,0,31"  \
441                                : "=r" (ret)     \
442                                : "r" (a), "I" (n));  \
443                            ret;             \
444                          })
445 #  endif
446 # endif
447 
448 /*
449  * Engage compiler specific "fetch in reverse byte order"
450  * intrinsic function if available.
451  */
452 # if defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
453 /* some GNU C inline assembler templates by <appro@fy.chalmers.se> */
454 #  if (defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)) && !defined(I386_ONLY)
455 #   define BE_FETCH32(a)    ({ register unsigned int l=(a); \
456                                asm (           \
457                                    "bswapl %0"     \
458                                    : "=r" (l) : "0" (l));    \
459                                l;                \
460                              })
461 #  elif defined(__powerpc)
462 #   define LE_FETCH32(a)    ({ register unsigned int l; \
463                                asm (           \
464                                    "lwbrx %0,0,%1"     \
465                                    : "=r" (l)       \
466                                    : "r" (a));      \
467                                l;               \
468                              })
469 
470 #  elif defined(__sparc) && defined(OPENSSL_SYS_ULTRASPARC)
471 #  define LE_FETCH32(a) ({ register unsigned int l;     \
472                            asm (               \
473                                "lda [%1]#ASI_PRIMARY_LITTLE,%0" \
474                                : "=r" (l)           \
475                                : "r" (a));          \
476                            l;                   \
477                          })
478 #  endif
479 # endif
480 #endif /* PEDANTIC */
481 
482 #if HASH_LONG_LOG2==2   /* Engage only if sizeof(HASH_LONG)== 4 */
483 /* A nice byte order reversal from Wei Dai <weidai@eskimo.com> */
484 #ifdef ROTATE
485 /* 5 instructions with rotate instruction, else 9 */
486 #define REVERSE_FETCH32(a,l)    (                   \
487         l=*(const HASH_LONG *)(a),              \
488         ((ROTATE(l,8)&0x00FF00FF)|(ROTATE((l&0x00FF00FF),24)))  \
489         )
490 #else
491 /* 6 instructions with rotate instruction, else 8 */
492 #define REVERSE_FETCH32(a,l)    (               \
493         l=*(const HASH_LONG *)(a),          \
494         l=(((l>>8)&0x00FF00FF)|((l&0x00FF00FF)<<8)),    \
495         ROTATE(l,16)                    \
496         )
497 /*
498  * Originally the middle line started with l=(((l&0xFF00FF00)>>8)|...
499  * It's rewritten as above for two reasons:
500  *        - RISCs aren't good at long constants and have to explicitely
501  *          compose 'em with several (well, usually 2) instructions in a
502  *          register before performing the actual operation and (as you
503  *          already realized:-) having same constant should inspire the
504  *          compiler to permanently allocate the only register for it;
505  *        - most modern CPUs have two ALUs, but usually only one has
506  *          circuitry for shifts:-( this minor tweak inspires compiler
507  *          to schedule shift instructions in a better way...
508  *
509  *                                      <appro@fy.chalmers.se>
510  */
511 #endif
512 #endif
513 
514 #ifndef ROTATE
515 #define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))
516 #endif
517 
518 /*
519  * Make some obvious choices. E.g., HASH_BLOCK_DATA_ORDER_ALIGNED
520  * and HASH_BLOCK_HOST_ORDER ought to be the same if input data
521  * and host are of the same "endianess". It's possible to mask
522  * this with blank #define HASH_BLOCK_DATA_ORDER though...
523  *
524  *                                      <appro@fy.chalmers.se>
525  */
526 #if defined(B_ENDIAN)
527 #  if defined(DATA_ORDER_IS_BIG_ENDIAN)
528 #    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
529 #      define HASH_BLOCK_DATA_ORDER_ALIGNED HASH_BLOCK_HOST_ORDER
530 #    endif
531 #  elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
532 #    ifndef HOST_FETCH32
533 #      ifdef LE_FETCH32
534 #        define HOST_FETCH32(p,l)   LE_FETCH32(p)
535 #      elif defined(REVERSE_FETCH32)
536 #        define HOST_FETCH32(p,l)   REVERSE_FETCH32(p,l)
537 #      endif
538 #    endif
539 #  endif
540 #elif defined(L_ENDIAN)
541 #  if defined(DATA_ORDER_IS_LITTLE_ENDIAN)
542 #    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
543 #      define HASH_BLOCK_DATA_ORDER_ALIGNED HASH_BLOCK_HOST_ORDER
544 #    endif
545 #  elif defined(DATA_ORDER_IS_BIG_ENDIAN)
546 #    ifndef HOST_FETCH32
547 #      ifdef BE_FETCH32
548 #        define HOST_FETCH32(p,l)   BE_FETCH32(p)
549 #      elif defined(REVERSE_FETCH32)
550 #        define HOST_FETCH32(p,l)   REVERSE_FETCH32(p,l)
551 #      endif
552 #    endif
553 #  endif
554 #endif
555 
556 #if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
557 #ifndef HASH_BLOCK_DATA_ORDER
558 #error "HASH_BLOCK_DATA_ORDER must be defined!"
559 #endif
560 #endif
561 
562 // None of the invocations of the following macros actually use the result,
563 // so cast them to void to avoid any compiler warnings/errors about not using
564 // the result (e.g. when using clang).
565 // If the resultant values need to be used at some point, these must be changed.
566 #define HOST_c2l(c,l) ((void)_HOST_c2l(c,l))
567 #define HOST_l2c(l,c) ((void)_HOST_l2c(l,c))
568 
569 #if defined(DATA_ORDER_IS_BIG_ENDIAN)
570 
571 #define _HOST_c2l(c,l)  (l =(((unsigned long)(*((c)++)))<<24),      \
572                          l|=(((unsigned long)(*((c)++)))<<16),      \
573                          l|=(((unsigned long)(*((c)++)))<< 8),      \
574                          l|=(((unsigned long)(*((c)++)))    ),      \
575                          l)
576 #define HOST_p_c2l(c,l,n)   {                       \
577         switch (n) {                                \
578         case 0: l =((unsigned long)(*((c)++)))<<24; \
579             fallthrough();                          \
580         case 1: l|=((unsigned long)(*((c)++)))<<16; \
581             fallthrough();                          \
582         case 2: l|=((unsigned long)(*((c)++)))<< 8; \
583             fallthrough();                          \
584         case 3: l|=((unsigned long)(*((c)++)));     \
585         } }
586 #define HOST_p_c2l_p(c,l,sc,len) {                  \
587         switch (sc) {                               \
588         case 0: l =((unsigned long)(*((c)++)))<<24; \
589             if (--len == 0) break;                  \
590             fallthrough();                          \
591         case 1: l|=((unsigned long)(*((c)++)))<<16; \
592             if (--len == 0) break;                  \
593             fallthrough();                          \
594         case 2: l|=((unsigned long)(*((c)++)))<< 8; \
595         } }
596 /* NOTE the pointer is not incremented at the end of this */
597 #define HOST_c2l_p(c,l,n)   {                       \
598         l=0; (c)+=n;                                \
599         switch (n) {                                \
600         case 3: l =((unsigned long)(*(--(c))))<< 8; \
601             fallthrough();                          \
602         case 2: l|=((unsigned long)(*(--(c))))<<16; \
603             fallthrough();                          \
604         case 1: l|=((unsigned long)(*(--(c))))<<24; \
605         } }
606 #define _HOST_l2c(l,c)  (*((c)++)=(unsigned char)(((l)>>24)&0xff),  \
607                          *((c)++)=(unsigned char)(((l)>>16)&0xff),  \
608                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),  \
609                          *((c)++)=(unsigned char)(((l)    )&0xff),  \
610                          l)
611 
612 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
613 
614 #define _HOST_c2l(c,l)  (l =(((unsigned long)(*((c)++)))    ),      \
615                          l|=(((unsigned long)(*((c)++)))<< 8),      \
616                          l|=(((unsigned long)(*((c)++)))<<16),      \
617                          l|=(((unsigned long)(*((c)++)))<<24),      \
618                          l)
619 #define HOST_p_c2l(c,l,n)   {                       \
620         switch (n) {                                \
621         case 0: l =((unsigned long)(*((c)++)));     \
622             fallthrough();                          \
623         case 1: l|=((unsigned long)(*((c)++)))<< 8; \
624             fallthrough();                          \
625         case 2: l|=((unsigned long)(*((c)++)))<<16; \
626             fallthrough();                          \
627         case 3: l|=((unsigned long)(*((c)++)))<<24; \
628         } }
629 #define HOST_p_c2l_p(c,l,sc,len) {                  \
630         switch (sc) {                               \
631         case 0: l =((unsigned long)(*((c)++)));     \
632             if (--len == 0) break;                  \
633             fallthrough();                          \
634         case 1: l|=((unsigned long)(*((c)++)))<< 8; \
635             if (--len == 0) break;                  \
636             fallthrough();                          \
637         case 2: l|=((unsigned long)(*((c)++)))<<16; \
638         } }
639 /* NOTE the pointer is not incremented at the end of this */
640 #define HOST_c2l_p(c,l,n)   {                       \
641         l=0; (c)+=n;                                \
642         switch (n) {                                \
643         case 3: l =((unsigned long)(*(--(c))))<<16; \
644             fallthrough();                          \
645         case 2: l|=((unsigned long)(*(--(c))))<< 8; \
646             fallthrough();                          \
647         case 1: l|=((unsigned long)(*(--(c))));     \
648         } }
649 #define _HOST_l2c(l,c)  (*((c)++)=(unsigned char)(((l)    )&0xff),  \
650                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),  \
651                          *((c)++)=(unsigned char)(((l)>>16)&0xff),  \
652                          *((c)++)=(unsigned char)(((l)>>24)&0xff),  \
653                          l)
654 
655 #endif
656 
657 #if defined(__GNUC__)
658 #pragma GCC diagnostic pop
659 #endif
660 
661 /*
662  * Time for some action:-)
663  */
664 
HASH_UPDATE(HASH_CTX * c,const void * data_,unsigned long len)665 int HASH_UPDATE (HASH_CTX *c, const void *data_, unsigned long len)
666 {
667     const unsigned char *data=(const unsigned char *)data_;
668     const unsigned char * const data_end=(const unsigned char *)data_ + len;
669     register HASH_LONG * p;
670     register unsigned long l;
671     int sw,sc,ew,ec;
672 
673     if (len==0) return 1;
674 
675     l=(c->Nl+(len<<3))&0xffffffffL;
676     /* 95-05-24 eay Fixed a bug with the overflow handling, thanks to
677      * Wei Dai <weidai@eskimo.com> for pointing it out. */
678     if (l < c->Nl) /* overflow */
679         c->Nh++;
680     c->Nh+=(len>>29);
681     c->Nl=l;
682 
683     if (c->num != 0)
684     {
685         p=c->data;
686         sw=c->num>>2;
687         sc=c->num&0x03;
688 
689         if ((c->num+len) >= HASH_CBLOCK)
690         {
691             l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l;
692             for (; (sw < HASH_LBLOCK) && ((data_end - data) >= 4); sw++)
693             {
694                 HOST_c2l(data,l); p[sw]=l;
695             }
696             HASH_BLOCK_HOST_ORDER (c,p,1);
697             len-=(HASH_CBLOCK-c->num);
698             c->num=0;
699             /* drop through and do the rest */
700         }
701         else
702         {
703             c->num+=len;
704             if ((sc+len) < 4) /* ugly, add char's to a word */
705             {
706                 l=p[sw]; HOST_p_c2l_p(data,l,sc,len); p[sw]=l;
707             }
708             else
709             {
710                 ew=(c->num>>2);
711                 ec=(c->num&0x03);
712                 if (sc)
713                     l=p[sw];
714                 HOST_p_c2l(data,l,sc);
715                 p[sw++]=l;
716                 for (; (sw < ew) && ((data_end - data) >= 4); sw++)
717                 {
718                     HOST_c2l(data,l); p[sw]=l;
719                 }
720                 if (ec)
721                 {
722                     HOST_c2l_p(data,l,ec); p[sw]=l;
723                 }
724             }
725             return 1;
726         }
727     }
728 
729     sw=(int)(len/HASH_CBLOCK);
730     if (sw > 0)
731     {
732 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
733         /*
734          * Note that HASH_BLOCK_DATA_ORDER_ALIGNED gets defined
735          * only if sizeof(HASH_LONG)==4.
736          */
737         if ((((unsigned long)data)%4) == 0)
738         {
739             /* data is properly aligned so that we can cast it: */
740             HASH_BLOCK_DATA_ORDER_ALIGNED (c,(HASH_LONG *)data,sw);
741             sw*=HASH_CBLOCK;
742             data+=sw;
743             len-=sw;
744         }
745         else
746 #if !defined(HASH_BLOCK_DATA_ORDER)
747             while (sw--)
748             {
749                 mDNSPlatformMemCopy(p=c->data,data,HASH_CBLOCK);
750                 HASH_BLOCK_DATA_ORDER_ALIGNED(c,p,1);
751                 data+=HASH_CBLOCK;
752                 len-=HASH_CBLOCK;
753             }
754 #endif
755 #endif
756 #if defined(HASH_BLOCK_DATA_ORDER)
757         {
758             HASH_BLOCK_DATA_ORDER(c,data,sw);
759             sw*=HASH_CBLOCK;
760             data+=sw;
761             len-=sw;
762         }
763 #endif
764     }
765 
766     if (len!=0)
767     {
768         p = c->data;
769         c->num = (int)len;
770         ew=(int)(len>>2);   /* words to copy */
771         ec=(int)(len&0x03);
772         for (; ew && ((data_end - data) >= 4); ew--,p++)
773         {
774             HOST_c2l(data,l); *p=l;
775         }
776         HOST_c2l_p(data,l,ec);
777         *p=l;
778     }
779     return 1;
780 }
781 
782 
HASH_TRANSFORM(HASH_CTX * c,const unsigned char * data)783 void HASH_TRANSFORM (HASH_CTX *c, const unsigned char *data)
784 {
785 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
786     if ((((unsigned long)data)%4) == 0)
787         /* data is properly aligned so that we can cast it: */
788         HASH_BLOCK_DATA_ORDER_ALIGNED (c,(HASH_LONG *)data,1);
789     else
790 #if !defined(HASH_BLOCK_DATA_ORDER)
791     {
792         mDNSPlatformMemCopy(c->data,data,HASH_CBLOCK);
793         HASH_BLOCK_DATA_ORDER_ALIGNED (c,c->data,1);
794     }
795 #endif
796 #endif
797 #if defined(HASH_BLOCK_DATA_ORDER)
798     HASH_BLOCK_DATA_ORDER (c,data,1);
799 #endif
800 }
801 
802 
HASH_FINAL(unsigned char * md,HASH_CTX * c)803 int HASH_FINAL (unsigned char *md, HASH_CTX *c)
804 {
805     register HASH_LONG *p;
806     register unsigned long l;
807     register int i,j;
808     static const unsigned char end[4]={0x80,0x00,0x00,0x00};
809     const unsigned char *cp=end;
810 
811     /* c->num should definitly have room for at least one more byte. */
812     p=c->data;
813     i=c->num>>2;
814     j=c->num&0x03;
815 
816 #if 0
817     /* purify often complains about the following line as an
818      * Uninitialized Memory Read.  While this can be true, the
819      * following p_c2l macro will reset l when that case is true.
820      * This is because j&0x03 contains the number of 'valid' bytes
821      * already in p[i].  If and only if j&0x03 == 0, the UMR will
822      * occur but this is also the only time p_c2l will do
823      * l= *(cp++) instead of l|= *(cp++)
824      * Many thanks to Alex Tang <altitude@cic.net> for pickup this
825      * 'potential bug' */
826 #ifdef PURIFY
827     if (j==0) p[i]=0; /* Yeah, but that's not the way to fix it:-) */
828 #endif
829     l=p[i];
830 #else
831     l = (j==0) ? 0 : p[i];
832 #endif
833     HOST_p_c2l(cp,l,j); p[i++]=l; /* i is the next 'undefined word' */
834 
835     if (i>(HASH_LBLOCK-2)) /* save room for Nl and Nh */
836     {
837         if (i<HASH_LBLOCK) p[i]=0;
838         HASH_BLOCK_HOST_ORDER (c,p,1);
839         i=0;
840     }
841     for (; i<(HASH_LBLOCK-2); i++)
842         p[i]=0;
843 
844 #if   defined(DATA_ORDER_IS_BIG_ENDIAN)
845     p[HASH_LBLOCK-2]=c->Nh;
846     p[HASH_LBLOCK-1]=c->Nl;
847 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
848     p[HASH_LBLOCK-2]=c->Nl;
849     p[HASH_LBLOCK-1]=c->Nh;
850 #endif
851     HASH_BLOCK_HOST_ORDER (c,p,1);
852 
853 #ifndef HASH_MAKE_STRING
854 #error "HASH_MAKE_STRING must be defined!"
855 #else
856     HASH_MAKE_STRING(c,md);
857 #endif
858 
859     c->num=0;
860     /* clear stuff, HASH_BLOCK may be leaving some stuff on the stack
861      * but I'm not worried :-)
862        OPENSSL_cleanse((void *)c,sizeof(HASH_CTX));
863      */
864     return 1;
865 }
866 
867 #ifndef MD32_REG_T
868 #define MD32_REG_T long
869 /*
870  * This comment was originaly written for MD5, which is why it
871  * discusses A-D. But it basically applies to all 32-bit digests,
872  * which is why it was moved to common header file.
873  *
874  * In case you wonder why A-D are declared as long and not
875  * as mDNSu32. Doing so results in slight performance
876  * boost on LP64 architectures. The catch is we don't
877  * really care if 32 MSBs of a 64-bit register get polluted
878  * with eventual overflows as we *save* only 32 LSBs in
879  * *either* case. Now declaring 'em long excuses the compiler
880  * from keeping 32 MSBs zeroed resulting in 13% performance
881  * improvement under SPARC Solaris7/64 and 5% under AlphaLinux.
882  * Well, to be honest it should say that this *prevents*
883  * performance degradation.
884  *                                      <appro@fy.chalmers.se>
885  * Apparently there're LP64 compilers that generate better
886  * code if A-D are declared int. Most notably GCC-x86_64
887  * generates better code.
888  *                                      <appro@fy.chalmers.se>
889  */
890 #endif
891 
892 
893 // from md5_locl.h (continued)
894 
895 /*
896  #define  F(x,y,z)  (((x) & (y))  |  ((~(x)) & (z)))
897  #define  G(x,y,z)  (((x) & (z))  |  ((y) & (~(z))))
898  */
899 
900 /* As pointed out by Wei Dai <weidai@eskimo.com>, the above can be
901  * simplified to the code below.  Wei attributes these optimizations
902  * to Peter Gutmann's SHS code, and he attributes it to Rich Schroeppel.
903  */
904 #define F(b,c,d)    ((((c) ^ (d)) & (b)) ^ (d))
905 #define G(b,c,d)    ((((b) ^ (c)) & (d)) ^ (c))
906 #define H(b,c,d)    ((b) ^ (c) ^ (d))
907 #define I(b,c,d)    (((~(d)) | (b)) ^ (c))
908 
909 #define R0(a,b,c,d,k,s,t) { \
910         a+=((k)+(t)+F((b),(c),(d))); \
911         a=ROTATE(a,s); \
912         a+=b; }; \
913 
914 #define R1(a,b,c,d,k,s,t) { \
915         a+=((k)+(t)+G((b),(c),(d))); \
916         a=ROTATE(a,s); \
917         a+=b; };
918 
919 #define R2(a,b,c,d,k,s,t) { \
920         a+=((k)+(t)+H((b),(c),(d))); \
921         a=ROTATE(a,s); \
922         a+=b; };
923 
924 #define R3(a,b,c,d,k,s,t) { \
925         a+=((k)+(t)+I((b),(c),(d))); \
926         a=ROTATE(a,s); \
927         a+=b; };
928 
929 // from md5_dgst.c
930 
931 
932 /* Implemented from RFC1321 The MD5 Message-Digest Algorithm
933  */
934 
935 #define INIT_DATA_A (unsigned long)0x67452301L
936 #define INIT_DATA_B (unsigned long)0xefcdab89L
937 #define INIT_DATA_C (unsigned long)0x98badcfeL
938 #define INIT_DATA_D (unsigned long)0x10325476L
939 
MD5_Init(MD5_CTX * c)940 int MD5_Init(MD5_CTX *c)
941 {
942     c->A=INIT_DATA_A;
943     c->B=INIT_DATA_B;
944     c->C=INIT_DATA_C;
945     c->D=INIT_DATA_D;
946     c->Nl=0;
947     c->Nh=0;
948     c->num=0;
949     return 1;
950 }
951 
952 #ifndef md5_block_host_order
md5_block_host_order(MD5_CTX * c,const void * data,int num)953 void md5_block_host_order (MD5_CTX *c, const void *data, int num)
954 {
955     const mDNSu32 *X=(const mDNSu32 *)data;
956     register unsigned MD32_REG_T A,B,C,D;
957 
958     A=c->A;
959     B=c->B;
960     C=c->C;
961     D=c->D;
962 
963     for (; num--; X+=HASH_LBLOCK)
964     {
965         /* Round 0 */
966 #if defined(__GNUC__)
967 #pragma GCC diagnostic push
968 #endif
969 #ifdef __clang__
970 #pragma GCC diagnostic ignored "-Wlanguage-extension-token"
971 #pragma GCC diagnostic ignored "-Wgnu-statement-expression"
972 #endif
973         R0(A,B,C,D,X[ 0], 7,0xd76aa478L);
974         R0(D,A,B,C,X[ 1],12,0xe8c7b756L);
975         R0(C,D,A,B,X[ 2],17,0x242070dbL);
976         R0(B,C,D,A,X[ 3],22,0xc1bdceeeL);
977         R0(A,B,C,D,X[ 4], 7,0xf57c0fafL);
978         R0(D,A,B,C,X[ 5],12,0x4787c62aL);
979         R0(C,D,A,B,X[ 6],17,0xa8304613L);
980         R0(B,C,D,A,X[ 7],22,0xfd469501L);
981         R0(A,B,C,D,X[ 8], 7,0x698098d8L);
982         R0(D,A,B,C,X[ 9],12,0x8b44f7afL);
983         R0(C,D,A,B,X[10],17,0xffff5bb1L);
984         R0(B,C,D,A,X[11],22,0x895cd7beL);
985         R0(A,B,C,D,X[12], 7,0x6b901122L);
986         R0(D,A,B,C,X[13],12,0xfd987193L);
987         R0(C,D,A,B,X[14],17,0xa679438eL);
988         R0(B,C,D,A,X[15],22,0x49b40821L);
989         /* Round 1 */
990         R1(A,B,C,D,X[ 1], 5,0xf61e2562L);
991         R1(D,A,B,C,X[ 6], 9,0xc040b340L);
992         R1(C,D,A,B,X[11],14,0x265e5a51L);
993         R1(B,C,D,A,X[ 0],20,0xe9b6c7aaL);
994         R1(A,B,C,D,X[ 5], 5,0xd62f105dL);
995         R1(D,A,B,C,X[10], 9,0x02441453L);
996         R1(C,D,A,B,X[15],14,0xd8a1e681L);
997         R1(B,C,D,A,X[ 4],20,0xe7d3fbc8L);
998         R1(A,B,C,D,X[ 9], 5,0x21e1cde6L);
999         R1(D,A,B,C,X[14], 9,0xc33707d6L);
1000         R1(C,D,A,B,X[ 3],14,0xf4d50d87L);
1001         R1(B,C,D,A,X[ 8],20,0x455a14edL);
1002         R1(A,B,C,D,X[13], 5,0xa9e3e905L);
1003         R1(D,A,B,C,X[ 2], 9,0xfcefa3f8L);
1004         R1(C,D,A,B,X[ 7],14,0x676f02d9L);
1005         R1(B,C,D,A,X[12],20,0x8d2a4c8aL);
1006         /* Round 2 */
1007         R2(A,B,C,D,X[ 5], 4,0xfffa3942L);
1008         R2(D,A,B,C,X[ 8],11,0x8771f681L);
1009         R2(C,D,A,B,X[11],16,0x6d9d6122L);
1010         R2(B,C,D,A,X[14],23,0xfde5380cL);
1011         R2(A,B,C,D,X[ 1], 4,0xa4beea44L);
1012         R2(D,A,B,C,X[ 4],11,0x4bdecfa9L);
1013         R2(C,D,A,B,X[ 7],16,0xf6bb4b60L);
1014         R2(B,C,D,A,X[10],23,0xbebfbc70L);
1015         R2(A,B,C,D,X[13], 4,0x289b7ec6L);
1016         R2(D,A,B,C,X[ 0],11,0xeaa127faL);
1017         R2(C,D,A,B,X[ 3],16,0xd4ef3085L);
1018         R2(B,C,D,A,X[ 6],23,0x04881d05L);
1019         R2(A,B,C,D,X[ 9], 4,0xd9d4d039L);
1020         R2(D,A,B,C,X[12],11,0xe6db99e5L);
1021         R2(C,D,A,B,X[15],16,0x1fa27cf8L);
1022         R2(B,C,D,A,X[ 2],23,0xc4ac5665L);
1023         /* Round 3 */
1024         R3(A,B,C,D,X[ 0], 6,0xf4292244L);
1025         R3(D,A,B,C,X[ 7],10,0x432aff97L);
1026         R3(C,D,A,B,X[14],15,0xab9423a7L);
1027         R3(B,C,D,A,X[ 5],21,0xfc93a039L);
1028         R3(A,B,C,D,X[12], 6,0x655b59c3L);
1029         R3(D,A,B,C,X[ 3],10,0x8f0ccc92L);
1030         R3(C,D,A,B,X[10],15,0xffeff47dL);
1031         R3(B,C,D,A,X[ 1],21,0x85845dd1L);
1032         R3(A,B,C,D,X[ 8], 6,0x6fa87e4fL);
1033         R3(D,A,B,C,X[15],10,0xfe2ce6e0L);
1034         R3(C,D,A,B,X[ 6],15,0xa3014314L);
1035         R3(B,C,D,A,X[13],21,0x4e0811a1L);
1036         R3(A,B,C,D,X[ 4], 6,0xf7537e82L);
1037         R3(D,A,B,C,X[11],10,0xbd3af235L);
1038         R3(C,D,A,B,X[ 2],15,0x2ad7d2bbL);
1039         R3(B,C,D,A,X[ 9],21,0xeb86d391L);
1040 #if defined(__GNUC__)
1041 #pragma GCC diagnostic pop
1042 #endif
1043 
1044         A = c->A += A;
1045         B = c->B += B;
1046         C = c->C += C;
1047         D = c->D += D;
1048     }
1049 }
1050 #endif
1051 
1052 #ifndef md5_block_data_order
1053 #ifdef X
1054 #undef X
1055 #endif
md5_block_data_order(MD5_CTX * c,const void * data_,int num)1056 void md5_block_data_order (MD5_CTX *c, const void *data_, int num)
1057 {
1058     const unsigned char *data=data_;
1059     register unsigned MD32_REG_T A,B,C,D,l;
1060 #ifndef MD32_XARRAY
1061     /* See comment in crypto/sha/sha_locl.h for details. */
1062     unsigned MD32_REG_T XX0, XX1, XX2, XX3, XX4, XX5, XX6, XX7,
1063                         XX8, XX9,XX10,XX11,XX12,XX13,XX14,XX15;
1064 # define X(i)   XX ## i
1065 #else
1066     mDNSu32 XX[MD5_LBLOCK];
1067 # define X(i)   XX[i]
1068 #endif
1069 
1070     A=c->A;
1071     B=c->B;
1072     C=c->C;
1073     D=c->D;
1074 
1075 #if defined(__clang_analyzer__)
1076     // Get rid of false positive analyzer warning.
1077     for (const unsigned char *_ptr = data; _ptr < &data[num * HASH_CBLOCK]; ++_ptr) {}
1078 #endif
1079     for (; num--;)
1080     {
1081         HOST_c2l(data,l); X( 0)=l;      HOST_c2l(data,l); X( 1)=l;
1082         /* Round 0 */
1083 #if defined(__GNUC__)
1084 #pragma GCC diagnostic push
1085 #endif
1086 #ifdef __clang__
1087 #pragma GCC diagnostic ignored "-Wlanguage-extension-token"
1088 #pragma GCC diagnostic ignored "-Wgnu-statement-expression"
1089 #endif
1090         R0(A,B,C,D,X( 0), 7,0xd76aa478L);   HOST_c2l(data,l); X( 2)=l;
1091         R0(D,A,B,C,X( 1),12,0xe8c7b756L);   HOST_c2l(data,l); X( 3)=l;
1092         R0(C,D,A,B,X( 2),17,0x242070dbL);   HOST_c2l(data,l); X( 4)=l;
1093         R0(B,C,D,A,X( 3),22,0xc1bdceeeL);   HOST_c2l(data,l); X( 5)=l;
1094         R0(A,B,C,D,X( 4), 7,0xf57c0fafL);   HOST_c2l(data,l); X( 6)=l;
1095         R0(D,A,B,C,X( 5),12,0x4787c62aL);   HOST_c2l(data,l); X( 7)=l;
1096         R0(C,D,A,B,X( 6),17,0xa8304613L);   HOST_c2l(data,l); X( 8)=l;
1097         R0(B,C,D,A,X( 7),22,0xfd469501L);   HOST_c2l(data,l); X( 9)=l;
1098         R0(A,B,C,D,X( 8), 7,0x698098d8L);   HOST_c2l(data,l); X(10)=l;
1099         R0(D,A,B,C,X( 9),12,0x8b44f7afL);   HOST_c2l(data,l); X(11)=l;
1100         R0(C,D,A,B,X(10),17,0xffff5bb1L);   HOST_c2l(data,l); X(12)=l;
1101         R0(B,C,D,A,X(11),22,0x895cd7beL);   HOST_c2l(data,l); X(13)=l;
1102         R0(A,B,C,D,X(12), 7,0x6b901122L);   HOST_c2l(data,l); X(14)=l;
1103         R0(D,A,B,C,X(13),12,0xfd987193L);   HOST_c2l(data,l); X(15)=l;
1104         R0(C,D,A,B,X(14),17,0xa679438eL);
1105         R0(B,C,D,A,X(15),22,0x49b40821L);
1106         /* Round 1 */
1107         R1(A,B,C,D,X( 1), 5,0xf61e2562L);
1108         R1(D,A,B,C,X( 6), 9,0xc040b340L);
1109         R1(C,D,A,B,X(11),14,0x265e5a51L);
1110         R1(B,C,D,A,X( 0),20,0xe9b6c7aaL);
1111         R1(A,B,C,D,X( 5), 5,0xd62f105dL);
1112         R1(D,A,B,C,X(10), 9,0x02441453L);
1113         R1(C,D,A,B,X(15),14,0xd8a1e681L);
1114         R1(B,C,D,A,X( 4),20,0xe7d3fbc8L);
1115         R1(A,B,C,D,X( 9), 5,0x21e1cde6L);
1116         R1(D,A,B,C,X(14), 9,0xc33707d6L);
1117         R1(C,D,A,B,X( 3),14,0xf4d50d87L);
1118         R1(B,C,D,A,X( 8),20,0x455a14edL);
1119         R1(A,B,C,D,X(13), 5,0xa9e3e905L);
1120         R1(D,A,B,C,X( 2), 9,0xfcefa3f8L);
1121         R1(C,D,A,B,X( 7),14,0x676f02d9L);
1122         R1(B,C,D,A,X(12),20,0x8d2a4c8aL);
1123         /* Round 2 */
1124         R2(A,B,C,D,X( 5), 4,0xfffa3942L);
1125         R2(D,A,B,C,X( 8),11,0x8771f681L);
1126         R2(C,D,A,B,X(11),16,0x6d9d6122L);
1127         R2(B,C,D,A,X(14),23,0xfde5380cL);
1128         R2(A,B,C,D,X( 1), 4,0xa4beea44L);
1129         R2(D,A,B,C,X( 4),11,0x4bdecfa9L);
1130         R2(C,D,A,B,X( 7),16,0xf6bb4b60L);
1131         R2(B,C,D,A,X(10),23,0xbebfbc70L);
1132         R2(A,B,C,D,X(13), 4,0x289b7ec6L);
1133         R2(D,A,B,C,X( 0),11,0xeaa127faL);
1134         R2(C,D,A,B,X( 3),16,0xd4ef3085L);
1135         R2(B,C,D,A,X( 6),23,0x04881d05L);
1136         R2(A,B,C,D,X( 9), 4,0xd9d4d039L);
1137         R2(D,A,B,C,X(12),11,0xe6db99e5L);
1138         R2(C,D,A,B,X(15),16,0x1fa27cf8L);
1139         R2(B,C,D,A,X( 2),23,0xc4ac5665L);
1140         /* Round 3 */
1141         R3(A,B,C,D,X( 0), 6,0xf4292244L);
1142         R3(D,A,B,C,X( 7),10,0x432aff97L);
1143         R3(C,D,A,B,X(14),15,0xab9423a7L);
1144         R3(B,C,D,A,X( 5),21,0xfc93a039L);
1145         R3(A,B,C,D,X(12), 6,0x655b59c3L);
1146         R3(D,A,B,C,X( 3),10,0x8f0ccc92L);
1147         R3(C,D,A,B,X(10),15,0xffeff47dL);
1148         R3(B,C,D,A,X( 1),21,0x85845dd1L);
1149         R3(A,B,C,D,X( 8), 6,0x6fa87e4fL);
1150         R3(D,A,B,C,X(15),10,0xfe2ce6e0L);
1151         R3(C,D,A,B,X( 6),15,0xa3014314L);
1152         R3(B,C,D,A,X(13),21,0x4e0811a1L);
1153         R3(A,B,C,D,X( 4), 6,0xf7537e82L);
1154         R3(D,A,B,C,X(11),10,0xbd3af235L);
1155         R3(C,D,A,B,X( 2),15,0x2ad7d2bbL);
1156         R3(B,C,D,A,X( 9),21,0xeb86d391L);
1157 #if defined(__GNUC__)
1158 #pragma GCC diagnostic pop
1159 #endif
1160 
1161         A = c->A += A;
1162         B = c->B += B;
1163         C = c->C += C;
1164         D = c->D += D;
1165     }
1166 }
1167 #endif
1168 
1169 
1170 // ***************************************************************************
1171 // MARK: - base64 -> binary conversion
1172 
1173 static const char Base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
1174 static const char Pad64 = '=';
1175 
1176 
1177 #define mDNSisspace(x) (x == '\t' || x == '\n' || x == '\v' || x == '\f' || x == '\r' || x == ' ')
1178 
mDNSstrchr(const char * s,int c)1179 mDNSlocal const char *mDNSstrchr(const char *s, int c)
1180 {
1181     while (1)
1182     {
1183         if (c == *s) return s;
1184         if (!*s) return mDNSNULL;
1185         s++;
1186     }
1187 }
1188 
1189 // skips all whitespace anywhere.
1190 // converts characters, four at a time, starting at (or after)
1191 // src from base - 64 numbers into three 8 bit bytes in the target area.
1192 // it returns the number of data bytes stored at the target, or -1 on error.
1193 // adapted from BIND sources
1194 
DNSDigest_Base64ToBin(const char * src,mDNSu8 * target,mDNSu32 targsize)1195 mDNSlocal mDNSs32 DNSDigest_Base64ToBin(const char *src, mDNSu8 *target, mDNSu32 targsize)
1196 {
1197     int tarindex, state, ch;
1198     const char *pos;
1199 
1200     state = 0;
1201     tarindex = 0;
1202 
1203     while ((ch = *src++) != '\0') {
1204         if (mDNSisspace(ch))    /* Skip whitespace anywhere. */
1205             continue;
1206 
1207         if (ch == Pad64)
1208             break;
1209 
1210         pos = mDNSstrchr(Base64, ch);
1211         if (pos == 0)       /* A non-base64 character. */
1212             return (-1);
1213 
1214         switch (state) {
1215         case 0:
1216             if (target) {
1217                 if ((mDNSu32)tarindex >= targsize)
1218                     return (-1);
1219                 target[tarindex] = (mDNSu8)((pos - Base64) << 2);
1220             }
1221             state = 1;
1222             break;
1223         case 1:
1224             if (target) {
1225                 if ((mDNSu32)tarindex + 1 >= targsize)
1226                     return (-1);
1227                 target[tarindex]   |=  (pos - Base64) >> 4;
1228                 target[tarindex+1]  = (mDNSu8)(((pos - Base64) & 0x0f) << 4);
1229             }
1230             tarindex++;
1231             state = 2;
1232             break;
1233         case 2:
1234             if (target) {
1235                 if ((mDNSu32)tarindex + 1 >= targsize)
1236                     return (-1);
1237                 target[tarindex]   |=  (pos - Base64) >> 2;
1238                 target[tarindex+1]  = (mDNSu8)(((pos - Base64) & 0x03) << 6);
1239             }
1240             tarindex++;
1241             state = 3;
1242             break;
1243         case 3:
1244             if (target) {
1245                 if ((mDNSu32)tarindex >= targsize)
1246                     return (-1);
1247                 target[tarindex] |= (pos - Base64);
1248             }
1249             tarindex++;
1250             state = 0;
1251             break;
1252         default:
1253             return -1;
1254         }
1255     }
1256 
1257     /*
1258      * We are done decoding Base-64 chars.  Let's see if we ended
1259      * on a byte boundary, and/or with erroneous trailing characters.
1260      */
1261 
1262     if (ch == Pad64) {      /* We got a pad char. */
1263         ch = *src++;        /* Skip it, get next. */
1264         switch (state) {
1265         case 0:     /* Invalid = in first position */
1266         case 1:     /* Invalid = in second position */
1267             return (-1);
1268 
1269         case 2:     /* Valid, means one byte of info */
1270             /* Skip any number of spaces. */
1271             for ((void)mDNSNULL; ch != '\0'; ch = *src++)
1272                 if (!mDNSisspace(ch))
1273                     break;
1274             /* Make sure there is another trailing = sign. */
1275             if (ch != Pad64)
1276                 return (-1);
1277             ch = *src++;        /* Skip the = */
1278         /* Fall through to "single trailing =" case. */
1279         /* FALLTHROUGH */
1280 
1281         case 3:     /* Valid, means two bytes of info */
1282             /*
1283              * We know this char is an =.  Is there anything but
1284              * whitespace after it?
1285              */
1286             for ((void)mDNSNULL; ch != '\0'; ch = *src++)
1287                 if (!mDNSisspace(ch))
1288                     return (-1);
1289 
1290             /*
1291              * Now make sure for cases 2 and 3 that the "extra"
1292              * bits that slopped past the last full byte were
1293              * zeros.  If we don't check them, they become a
1294              * subliminal channel.
1295              */
1296             if (target && target[tarindex] != 0)
1297                 return (-1);
1298         }
1299     } else {
1300         /*
1301          * We ended by seeing the end of the string.  Make sure we
1302          * have no partial bytes lying around.
1303          */
1304         if (state != 0)
1305             return (-1);
1306     }
1307 
1308     return (tarindex);
1309 }
1310 
1311 
1312 // ***************************************************************************
1313 // MARK: - API exported to mDNS Core
1314 
1315 // TSIG HMAC names from <https://datatracker.ietf.org/doc/html/rfc8945#section-6>
1316 // Currently, we do not support the truncated algorithms listed by the link above.
1317 
1318 #define kHMAC_MD5_AlgName    ((const domainname *)"\x8" "hmac-md5" "\x7" "sig-alg" "\x3" "reg" "\x3" "int")
1319 
1320 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1321 
1322 #define kHMAC_None_AlgName      ((const domainname *)"\xC" "hmac-invalid")
1323 #define kHMAC_SHA1_AlgName      ((const domainname *)"\x9" "hmac-sha1")
1324 #define kHMAC_SHA224_AlgName    ((const domainname *)"\xB" "hmac-sha224")
1325 #define kHMAC_SHA256_AlgName    ((const domainname *)"\xB" "hmac-sha256")
1326 #define kHMAC_SHA384_AlgName    ((const domainname *)"\xB" "hmac-sha384")
1327 #define kHMAC_SHA512_AlgName    ((const domainname *)"\xB" "hmac-sha512")
1328 
1329 // Since each HMAC algorithm has the most secure key length, we use the key length to determine which HMAC algorithm
1330 // should be used.
DNSDigest_GetHMACAlgorithmFromKeyLengthInBytes(const mDNSu32 length)1331 mDNSlocal DNSDigest_HMACAlgorithm DNSDigest_GetHMACAlgorithmFromKeyLengthInBytes(const mDNSu32 length)
1332 {
1333     switch (length) {
1334         case kDNSDigest_HMACMD5_KeyLengthInBytes:
1335             return kDNSDigest_HMACAlg_MD5;
1336         case kDNSDigest_HMACSHA1_KeyLengthInBytes:
1337             return kDNSDigest_HMACAlg_SHA1;
1338         case kDNSDigest_HMACSHA224_KeyLengthInBytes:
1339             return kDNSDigest_HMACAlg_SHA224;
1340         case kDNSDigest_HMACSHA256_KeyLengthInBytes:
1341             return kDNSDigest_HMACAlg_SHA256;
1342         case kDNSDigest_HMACSHA384_KeyLengthInBytes:
1343             return kDNSDigest_HMACAlg_SHA384;
1344         case kDNSDigest_HMACSHA512_KeyLengthInBytes:
1345             return kDNSDigest_HMACAlg_SHA512;
1346         default:
1347             LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "Invalid HMAC key length, unable to get algorithm type"
1348                 " - key length: %u", length);
1349             return kDNSDigest_HMACAlg_None;
1350     }
1351 }
1352 
1353 // Convert DNSDigest_HMACAlgorithm to CCHmacAlgorithm that is used by CoreCrypto.
DNSDigest_GetCCHmacAlgorithm(const DNSDigest_HMACAlgorithm algorithm)1354 mDNSlocal CCHmacAlgorithm DNSDigest_GetCCHmacAlgorithm(const DNSDigest_HMACAlgorithm algorithm)
1355 {
1356     switch (algorithm) {
1357         case kDNSDigest_HMACAlg_None:
1358             return kCCHmacAlgSHA512;
1359         case kDNSDigest_HMACAlg_MD5:
1360             return kCCHmacAlgMD5;
1361         case kDNSDigest_HMACAlg_SHA1:
1362             return kCCHmacAlgSHA1;
1363         case kDNSDigest_HMACAlg_SHA224:
1364             return kCCHmacAlgSHA224;
1365         case kDNSDigest_HMACAlg_SHA256:
1366             return kCCHmacAlgSHA256;
1367         case kDNSDigest_HMACAlg_SHA384:
1368             return kCCHmacAlgSHA384;
1369         case kDNSDigest_HMACAlg_SHA512:
1370             return kCCHmacAlgSHA512;
1371     }
1372 }
1373 
1374 // Get the signature output length of each algorithm.
DNSDigest_GetHMACOutputLength(const DNSDigest_HMACAlgorithm algorithm)1375 mDNSlocal mDNSu16 DNSDigest_GetHMACOutputLength(const DNSDigest_HMACAlgorithm algorithm)
1376 {
1377     switch (algorithm) {
1378         case kDNSDigest_HMACAlg_None:
1379             return 0;
1380         case kDNSDigest_HMACAlg_MD5:
1381             return kDNSDigest_HMACMD5_OutputLengthInBytes;
1382         case kDNSDigest_HMACAlg_SHA1:
1383             return kDNSDigest_HMACSHA1_OutputLengthInBytes;
1384         case kDNSDigest_HMACAlg_SHA224:
1385             return kDNSDigest_HMACSHA224_OutputLengthInBytes;
1386         case kDNSDigest_HMACAlg_SHA256:
1387             return kDNSDigest_HMACSHA256_OutputLengthInBytes;
1388         case kDNSDigest_HMACAlg_SHA384:
1389             return kDNSDigest_HMACSHA384_OutputLengthInBytes;
1390         case kDNSDigest_HMACAlg_SHA512:
1391             return kDNSDigest_HMACSHA512_OutputLengthInBytes;
1392     }
1393 }
1394 
1395 // Get the domain name format algorithm identifier for the given algorithm.
DNSDigest_GetHMACName(const DNSDigest_HMACAlgorithm algorithm)1396 mDNSlocal const domainname *DNSDigest_GetHMACName(const DNSDigest_HMACAlgorithm algorithm)
1397 {
1398     switch (algorithm) {
1399         case kDNSDigest_HMACAlg_None:
1400             return kHMAC_None_AlgName;
1401         case kDNSDigest_HMACAlg_MD5:
1402             return kHMAC_MD5_AlgName;
1403         case kDNSDigest_HMACAlg_SHA1:
1404             return kHMAC_SHA1_AlgName;
1405         case kDNSDigest_HMACAlg_SHA224:
1406             return kHMAC_SHA224_AlgName;
1407         case kDNSDigest_HMACAlg_SHA256:
1408             return kHMAC_SHA256_AlgName;
1409         case kDNSDigest_HMACAlg_SHA384:
1410             return kHMAC_SHA384_AlgName;
1411         case kDNSDigest_HMACAlg_SHA512:
1412             return kHMAC_SHA512_AlgName;
1413     }
1414 }
1415 
1416 // Get the algorithm enum given the domain name format algorithm identifier.
DNSDigest_GetHMACAlgorithmFromName(const domainname * const algorithmName)1417 mDNSlocal DNSDigest_HMACAlgorithm DNSDigest_GetHMACAlgorithmFromName(const domainname *const algorithmName)
1418 {
1419     if (algorithmName == mDNSNULL)
1420     {
1421         return kDNSDigest_HMACAlg_None;
1422     }
1423     else if (SameDomainName(algorithmName, kHMAC_MD5_AlgName))
1424     {
1425         return kDNSDigest_HMACAlg_MD5;
1426     }
1427     else if (SameDomainName(algorithmName, kHMAC_SHA1_AlgName))
1428     {
1429         return kDNSDigest_HMACAlg_SHA1;
1430     }
1431     else if (SameDomainName(algorithmName, kHMAC_SHA224_AlgName))
1432     {
1433         return kDNSDigest_HMACAlg_SHA224;
1434     }
1435     else if (SameDomainName(algorithmName, kHMAC_SHA256_AlgName))
1436     {
1437         return kDNSDigest_HMACAlg_SHA256;
1438     }
1439     else if (SameDomainName(algorithmName, kHMAC_SHA384_AlgName))
1440     {
1441         return kDNSDigest_HMACAlg_SHA384;
1442     }
1443     else if (SameDomainName(algorithmName, kHMAC_SHA512_AlgName))
1444     {
1445         return kDNSDigest_HMACAlg_SHA512;
1446     }
1447     else
1448     {
1449         return kDNSDigest_HMACAlg_None;
1450     }
1451 }
1452 
1453 #else // MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1454 
1455 // Constants
1456 #define HMAC_IPAD   0x36
1457 #define HMAC_OPAD   0x5c
1458 #define MD5_LEN     16
1459 
1460 // Adapted from Appendix, RFC 2104
DNSDigest_ConstructHMACKey(DomainAuthInfo * info,const mDNSu8 * key,mDNSu32 len)1461 mDNSlocal void DNSDigest_ConstructHMACKey(DomainAuthInfo *info, const mDNSu8 *key, mDNSu32 len)
1462 {
1463     MD5_CTX k;
1464     mDNSu8 buf[MD5_LEN];
1465     int i;
1466 
1467     // If key is longer than HMAC_LEN reset it to MD5(key)
1468     if (len > HMAC_LEN)
1469     {
1470         MD5_Init(&k);
1471         MD5_Update(&k, key, len);
1472         MD5_Final(buf, &k);
1473         key = buf;
1474         len = MD5_LEN;
1475     }
1476 
1477     // store key in pads
1478     mDNSPlatformMemZero(info->keydata_ipad, HMAC_LEN);
1479     mDNSPlatformMemZero(info->keydata_opad, HMAC_LEN);
1480     mDNSPlatformMemCopy(info->keydata_ipad, key, len);
1481     mDNSPlatformMemCopy(info->keydata_opad, key, len);
1482 
1483     // XOR key with ipad and opad values
1484     for (i = 0; i < HMAC_LEN; i++)
1485     {
1486         info->keydata_ipad[i] ^= HMAC_IPAD;
1487         info->keydata_opad[i] ^= HMAC_OPAD;
1488     }
1489 
1490 }
1491 
1492 #endif // MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1493 
DNSDigest_ConstructHMACKeyfromBase64(DomainAuthInfo * info,const char * b64key)1494 mDNSexport mDNSs32 DNSDigest_ConstructHMACKeyfromBase64(DomainAuthInfo *info, const char *b64key)
1495 {
1496     mDNSu8 keybuf[1024];
1497     mDNSs32 keylen = DNSDigest_Base64ToBin(b64key, keybuf, sizeof(keybuf));
1498     if (keylen < 0) return(keylen);
1499 
1500 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1501     info->key_len = (mDNSu32)keylen;
1502     info->algorithm = DNSDigest_GetHMACAlgorithmFromKeyLengthInBytes(info->key_len);
1503     if (info->algorithm == kDNSDigest_HMACAlg_None)
1504     {
1505         LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR,
1506             "Invalid HMAC secret key length, should be 16(HMAC MD5), 20(HMAC SHA1), 28(HMAC SHA224), 32(HMAC SHA256), 48(HMAC SHA384) or 64(HMAC SHA512)"
1507             " - actual length: %u", info->key_len);
1508         return -1;
1509     }
1510 
1511     if (sizeof(info->key) < (size_t)keylen)
1512     {
1513         LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_FAULT, "Key is too long, unable to save it in the buffer - "
1514             "buffer length: %zu, actual key length: %d", sizeof(info->key), keylen);
1515         return -1;
1516     }
1517     memcpy(info->key, keybuf, keylen);
1518 #else
1519     DNSDigest_ConstructHMACKey(info, keybuf, (mDNSu32)keylen);
1520 #endif
1521 
1522     return(keylen);
1523 }
1524 
DNSDigest_SignMessage(DNSMessage * msg,mDNSu8 ** end,DomainAuthInfo * info,mDNSu16 tcode)1525 mDNSexport void DNSDigest_SignMessage(DNSMessage *msg, mDNSu8 **end, DomainAuthInfo *info, mDNSu16 tcode)
1526 {
1527     AuthRecord tsig;
1528     mDNSu8  *rdata, *const countPtr = (mDNSu8 *)&msg->h.numAdditionals; // Get existing numAdditionals value
1529     mDNSu32 utc32;
1530     mDNSu8 utc48[6];
1531 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1532     mDNSu8 digest[kDNSDigest_HMACOutputLengthInBytesMAX];
1533 #else
1534     mDNSu8 digest[MD5_LEN];
1535 #endif
1536     mDNSu8 *ptr = *end;
1537     mDNSu32 len;
1538     mDNSOpaque16 buf;
1539     mDNSu16 numAdditionals = (mDNSu16)((mDNSu16)countPtr[0] << 8 | countPtr[1]);
1540 
1541 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1542     const DNSDigest_HMACAlgorithm algorithm = info->algorithm;
1543     CCHmacContext hmacContext;
1544 #else
1545     MD5_CTX c;
1546 #endif
1547 
1548     // Initialize HMAC context.
1549 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1550     CCHmacInit(&hmacContext, DNSDigest_GetCCHmacAlgorithm(algorithm), info->key, info->key_len);
1551 #else
1552     // Init MD5 context, digest inner key pad and message
1553     MD5_Init(&c);
1554     MD5_Update(&c, info->keydata_ipad, HMAC_LEN);
1555 #endif
1556 
1557     // Digest the entire DNS message.
1558 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1559     CCHmacUpdate(&hmacContext, (mDNSu8 *)msg, (size_t)(*end - (mDNSu8 *)msg));
1560 #else
1561     MD5_Update(&c, (mDNSu8 *)msg, (unsigned long)(*end - (mDNSu8 *)msg));
1562 #endif
1563 
1564     // Construct TSIG RR, digesting variables as apporpriate
1565     mDNS_SetupResourceRecord(&tsig, mDNSNULL, 0, kDNSType_TSIG, 0, kDNSRecordTypeKnownUnique, AuthRecordAny, mDNSNULL, mDNSNULL);
1566 
1567     // key name
1568     AssignDomainName(&tsig.namestorage, &info->keyname);
1569 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1570     CCHmacUpdate(&hmacContext, info->keyname.c, DomainNameLength(&info->keyname));
1571 #else
1572     MD5_Update(&c, info->keyname.c, DomainNameLength(&info->keyname));
1573 #endif
1574 
1575     // class
1576     tsig.resrec.rrclass = kDNSQClass_ANY;
1577     buf = mDNSOpaque16fromIntVal(kDNSQClass_ANY);
1578 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1579     CCHmacUpdate(&hmacContext, buf.b, sizeof(mDNSOpaque16));
1580 #else
1581     MD5_Update(&c, buf.b, sizeof(mDNSOpaque16));
1582 #endif
1583 
1584     // ttl
1585     tsig.resrec.rroriginalttl = 0;
1586 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1587     CCHmacUpdate(&hmacContext, (mDNSu8 *)&tsig.resrec.rroriginalttl, sizeof(tsig.resrec.rroriginalttl));
1588 #else
1589     MD5_Update(&c, (mDNSu8 *)&tsig.resrec.rroriginalttl, sizeof(tsig.resrec.rroriginalttl));
1590 #endif
1591 
1592     // alg name
1593 
1594 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1595     const domainname *const algorithmName = DNSDigest_GetHMACName(algorithm);
1596 #else
1597     const domainname *const algorithmName = kHMAC_MD5_AlgName;
1598 #endif
1599 
1600     AssignDomainName(&tsig.resrec.rdata->u.name, algorithmName);
1601     len = DomainNameLength(algorithmName);
1602     rdata = tsig.resrec.rdata->u.data + len;
1603 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1604     CCHmacUpdate(&hmacContext, (mDNSu8 *)algorithmName, len);
1605 #else
1606     MD5_Update(&c, (mDNSu8 *)algorithmName, len);
1607 #endif
1608 
1609     // time
1610     // get UTC (universal time), convert to 48-bit unsigned in network byte order
1611     utc32 = (mDNSu32)mDNSPlatformUTC();
1612     if (utc32 == (unsigned)-1) { LogMsg("ERROR: DNSDigest_SignMessage - mDNSPlatformUTC returned bad time -1"); *end = mDNSNULL; }
1613     utc48[0] = 0;
1614     utc48[1] = 0;
1615     utc48[2] = (mDNSu8)((utc32 >> 24) & 0xff);
1616     utc48[3] = (mDNSu8)((utc32 >> 16) & 0xff);
1617     utc48[4] = (mDNSu8)((utc32 >>  8) & 0xff);
1618     utc48[5] = (mDNSu8)( utc32        & 0xff);
1619 
1620     mDNSPlatformMemCopy(rdata, utc48, 6);
1621     rdata += 6;
1622 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1623     CCHmacUpdate(&hmacContext, utc48, 6);
1624 #else
1625     MD5_Update(&c, utc48, 6);
1626 #endif
1627 
1628     // 300 sec is fudge recommended in RFC 2485
1629     rdata[0] = (mDNSu8)((300 >> 8)  & 0xff);
1630     rdata[1] = (mDNSu8)( 300        & 0xff);
1631 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1632     CCHmacUpdate(&hmacContext, rdata, sizeof(mDNSOpaque16));
1633 #else
1634     MD5_Update(&c, rdata, sizeof(mDNSOpaque16));
1635 #endif
1636     rdata += sizeof(mDNSOpaque16);
1637 
1638     // digest error (tcode) and other data len (zero) - we'll add them to the rdata later
1639     buf.b[0] = (mDNSu8)((tcode >> 8) & 0xff);
1640     buf.b[1] = (mDNSu8)( tcode       & 0xff);
1641 
1642     // error code
1643 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1644     CCHmacUpdate(&hmacContext, buf.b, sizeof(mDNSOpaque16));
1645 #else
1646     MD5_Update(&c, buf.b, sizeof(mDNSOpaque16));
1647 #endif
1648 
1649     // other data len
1650     buf.NotAnInteger = 0;
1651 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1652     CCHmacUpdate(&hmacContext, buf.b, sizeof(mDNSOpaque16));
1653 #else
1654     MD5_Update(&c, buf.b, sizeof(mDNSOpaque16));
1655 #endif
1656 
1657     mDNSu16 digestLen = 0;
1658 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1659     CCHmacFinal(&hmacContext, digest);
1660     digestLen = DNSDigest_GetHMACOutputLength(algorithm);
1661 #else
1662     // finish the message & tsig var hash
1663     MD5_Final(digest, &c);
1664 
1665     // perform outer MD5 (outer key pad, inner digest)
1666     MD5_Init(&c);
1667     MD5_Update(&c, info->keydata_opad, HMAC_LEN);
1668     MD5_Update(&c, digest, MD5_LEN);
1669     MD5_Final(digest, &c);
1670     digestLen = MD5_LEN;
1671 #endif
1672 
1673     // set remaining rdata fields
1674     rdata[0] = (mDNSu8)((digestLen >> 8)  & 0xff);
1675     rdata[1] = (mDNSu8)( digestLen        & 0xff);
1676     rdata += sizeof(mDNSOpaque16);
1677     mDNSPlatformMemCopy(rdata, digest, digestLen);                        // MAC
1678     rdata += digestLen;
1679     rdata[0] = msg->h.id.b[0];                                            // original ID
1680     rdata[1] = msg->h.id.b[1];
1681     rdata[2] = (mDNSu8)((tcode >> 8) & 0xff);
1682     rdata[3] = (mDNSu8)( tcode       & 0xff);
1683     rdata[4] = 0;                                                         // other data len
1684     rdata[5] = 0;
1685     rdata += 6;
1686 
1687     tsig.resrec.rdlength = (mDNSu16)(rdata - tsig.resrec.rdata->u.data);
1688     *end = PutResourceRecordTTLJumbo(msg, ptr, &numAdditionals, &tsig.resrec, 0);
1689     if (!*end) { LogMsg("ERROR: DNSDigest_SignMessage - could not put TSIG"); *end = mDNSNULL; return; }
1690 
1691     // Write back updated numAdditionals value
1692     countPtr[0] = (mDNSu8)(numAdditionals >> 8);
1693     countPtr[1] = (mDNSu8)(numAdditionals &  0xFF);
1694 }
1695 
DNSDigest_VerifyMessage(const DNSMessage * const msg,const mDNSu8 * const end,const LargeCacheRecord * const lcr,const DomainAuthInfo * const info,mDNSu16 * const rcode,mDNSu16 * const tcode)1696 mDNSexport mDNSBool DNSDigest_VerifyMessage(const DNSMessage *const msg, const mDNSu8 *const end,
1697     const LargeCacheRecord *const lcr, const DomainAuthInfo *const info, mDNSu16 *const rcode, mDNSu16 *const tcode)
1698 {
1699     mDNSu8          *   ptr = (mDNSu8*) &lcr->r.resrec.rdata->u.data;
1700     mDNSs32 now;
1701     mDNSs32 then;
1702 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1703     mDNSu8 thisDigest[kDNSDigest_HMACOutputLengthInBytesMAX];
1704     mDNSu8 thatDigest[kDNSDigest_HMACOutputLengthInBytesMAX];
1705 #else
1706     mDNSu8 thisDigest[MD5_LEN];
1707     mDNSu8 thatDigest[MD5_LEN];
1708 #endif
1709     mDNSOpaque16 buf;
1710     mDNSu8 utc48[6];
1711     mDNSs32 delta;
1712     mDNSu16 fudge;
1713     domainname      *   algo;
1714     mDNSBool ok = mDNSfalse;
1715 
1716     // We only support HMAC-MD5 for now
1717 
1718     algo = (domainname*) ptr;
1719 
1720 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1721     const DNSDigest_HMACAlgorithm algorithm = DNSDigest_GetHMACAlgorithmFromName(algo);
1722     CCHmacContext hmacContext;
1723     if (algorithm == kDNSDigest_HMACAlg_None || algorithm != info->algorithm)
1724 #else
1725     MD5_CTX c;
1726     if (!SameDomainName(algo, kHMAC_MD5_AlgName))
1727 #endif
1728     {
1729         LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "TSIG algorithm not supported - "
1730             "algorithm name: " PUB_DM_NAME, DM_NAME_PARAM(algo));
1731         *rcode = kDNSFlag1_RC_NotAuth;
1732         *tcode = TSIG_ErrBadKey;
1733         ok = mDNSfalse;
1734         goto exit;
1735     }
1736 
1737     ptr += DomainNameLength(algo);
1738 
1739     // Check the times
1740 
1741     now = mDNSPlatformUTC();
1742     if (now == -1)
1743     {
1744         LogMsg("ERROR: DNSDigest_VerifyMessage - mDNSPlatformUTC returned bad time -1");
1745         *rcode = kDNSFlag1_RC_NotAuth;
1746         *tcode = TSIG_ErrBadTime;
1747         ok = mDNSfalse;
1748         goto exit;
1749     }
1750 
1751     // Get the 48 bit time field, skipping over the first word
1752 
1753     utc48[0] = *ptr++;
1754     utc48[1] = *ptr++;
1755     utc48[2] = *ptr++;
1756     utc48[3] = *ptr++;
1757     utc48[4] = *ptr++;
1758     utc48[5] = *ptr++;
1759 
1760     then  = (mDNSs32)NToH32(utc48 + sizeof(mDNSu16));
1761 
1762     fudge = NToH16(ptr);
1763 
1764     ptr += sizeof(mDNSu16);
1765 
1766     delta = (now > then) ? now - then : then - now;
1767 
1768     if (delta > fudge)
1769     {
1770         LogMsg("ERROR: DNSDigest_VerifyMessage - time skew > %d", fudge);
1771         *rcode = kDNSFlag1_RC_NotAuth;
1772         *tcode = TSIG_ErrBadTime;
1773         ok = mDNSfalse;
1774         goto exit;
1775     }
1776 
1777     // MAC size
1778 
1779     const mDNSu16 hmacLength = NToH16(ptr);
1780     ptr += sizeof(mDNSu16);
1781 
1782     // MAC
1783 
1784     mDNSPlatformMemCopy(thatDigest, ptr, hmacLength);
1785 
1786     // Initialize HMAC context.
1787 
1788 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1789     CCHmacInit(&hmacContext, DNSDigest_GetCCHmacAlgorithm(algorithm), info->key, info->key_len);
1790 #else
1791     // Init MD5 context, digest inner key pad and message
1792     MD5_Init(&c);
1793     MD5_Update(&c, info->keydata_ipad, HMAC_LEN);
1794 #endif
1795 
1796     // Digest the entire DNS message.
1797 
1798 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1799     CCHmacUpdate(&hmacContext, (mDNSu8 *)msg, (size_t)(end - (mDNSu8 *)msg));
1800 #else
1801     MD5_Update(&c, (mDNSu8*) msg, (unsigned long)(end - (mDNSu8*) msg));
1802 #endif
1803 
1804     // Key name
1805 
1806 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1807     CCHmacUpdate(&hmacContext, lcr->r.resrec.name->c, DomainNameLength(lcr->r.resrec.name));
1808 #else
1809     MD5_Update(&c, lcr->r.resrec.name->c, DomainNameLength(lcr->r.resrec.name));
1810 #endif
1811 
1812     // Class name
1813 
1814     buf = mDNSOpaque16fromIntVal(lcr->r.resrec.rrclass);
1815 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1816     CCHmacUpdate(&hmacContext, buf.b, sizeof(mDNSOpaque16));
1817 #else
1818     MD5_Update(&c, buf.b, sizeof(mDNSOpaque16));
1819 #endif
1820 
1821     // TTL
1822 
1823 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1824     CCHmacUpdate(&hmacContext, (mDNSu8 *) &lcr->r.resrec.rroriginalttl, sizeof(lcr->r.resrec.rroriginalttl));
1825 #else
1826     MD5_Update(&c, (mDNSu8*) &lcr->r.resrec.rroriginalttl, sizeof(lcr->r.resrec.rroriginalttl));
1827 #endif
1828 
1829     // Algorithm
1830 
1831 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1832     CCHmacUpdate(&hmacContext, algo->c, DomainNameLength(algo));
1833 #else
1834     MD5_Update(&c, algo->c, DomainNameLength(algo));
1835 #endif
1836 
1837     // Time
1838 
1839 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1840     CCHmacUpdate(&hmacContext, utc48, 6);
1841 #else
1842     MD5_Update(&c, utc48, 6);
1843 #endif
1844 
1845     // Fudge
1846 
1847     buf = mDNSOpaque16fromIntVal(fudge);
1848 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1849     CCHmacUpdate(&hmacContext, buf.b, sizeof(mDNSOpaque16));
1850 #else
1851     MD5_Update(&c, buf.b, sizeof(mDNSOpaque16));
1852 #endif
1853 
1854     // Digest error and other data len (both zero) - we'll add them to the rdata later
1855 
1856     buf.NotAnInteger = 0;
1857 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1858     CCHmacUpdate(&hmacContext, buf.b, sizeof(mDNSOpaque16)); // error
1859     CCHmacUpdate(&hmacContext, buf.b, sizeof(mDNSOpaque16)); // other data len
1860 #else
1861     MD5_Update(&c, buf.b, sizeof(mDNSOpaque16));  // error
1862     MD5_Update(&c, buf.b, sizeof(mDNSOpaque16));  // other data len
1863 #endif
1864 
1865     // Get the HMAC output.
1866 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1867     mDNSu16 digestLen = 0;
1868     CCHmacFinal(&hmacContext, thisDigest);
1869     digestLen = DNSDigest_GetHMACOutputLength(algorithm);
1870 #else
1871     // Finish the message & tsig var hash
1872 
1873     MD5_Final(thisDigest, &c);
1874 
1875     // perform outer MD5 (outer key pad, inner digest)
1876 
1877     MD5_Init(&c);
1878     MD5_Update(&c, info->keydata_opad, HMAC_LEN);
1879     MD5_Update(&c, thisDigest, MD5_LEN);
1880     MD5_Final(thisDigest, &c);
1881 #endif
1882 
1883 #if MDNSRESPONDER_SUPPORTS(APPLE, SECURE_HMAC_ALGORITHM_2022)
1884     // The MAC must be verified by comparing the computed and expected values using timingsafe_bcmp. Other comparison
1885     // functions (e.g. memcmp) must not be used as they may be vulnerable to practical timing attacks, leading to MAC
1886     // forgery.
1887     if (timingsafe_bcmp(thisDigest, thatDigest, digestLen))
1888 #else
1889     if (!mDNSPlatformMemSame(thisDigest, thatDigest, MD5_LEN))
1890 #endif
1891     {
1892         LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_ERROR, "DNSDigest_VerifyMessage - bad signature");
1893         *rcode = kDNSFlag1_RC_NotAuth;
1894         *tcode = TSIG_ErrBadSig;
1895         ok = mDNSfalse;
1896         goto exit;
1897     }
1898 
1899     // set remaining rdata fields
1900     ok = mDNStrue;
1901 
1902 exit:
1903 
1904     return ok;
1905 }
1906 
1907 #if defined(DEBUG) && DEBUG
1908 
1909 // This function is used for debug purpose to ensure that the signature generated by DNSDigest_SignMessage can be
1910 // authenticated by DNSDigest_VerifyMessage.
DNSDigest_VerifyMessage_Verify(DNSMessage * const msg,const mDNSu8 * const end,const DomainAuthInfo * const authInfo)1911 mDNSexport void DNSDigest_VerifyMessage_Verify(DNSMessage *const msg, const mDNSu8 *const end,
1912     const DomainAuthInfo *const authInfo)
1913 {
1914     // Convert from network byte order to host byte order.
1915     SwapDNSHeaderBytes(msg);
1916 
1917     // Locate the TSIG record in the additional section.
1918     mDNSBool verified;
1919     if (!msg->h.numAdditionals)
1920     {
1921         verified = mDNSfalse;
1922         goto exit;
1923     }
1924 
1925     const mDNSu8 *ptr = LocateAdditionals(msg, end);
1926     if (!ptr)
1927     {
1928         verified = mDNSfalse;
1929         goto exit;
1930     }
1931 
1932     const mDNSu8 *lastPtr = mDNSNULL;
1933     LargeCacheRecord lcr = {0};
1934     mDNSBool hasTSIGAtLast = mDNSfalse;
1935     for (mDNSu32 i = 0; i < msg->h.numAdditionals; i++)
1936     {
1937         lastPtr = ptr;
1938         ptr = GetLargeResourceRecord(mDNSNULL, msg, ptr, end, 0, kDNSRecordTypePacketAdd, &lcr);
1939         if (!ptr)
1940         {
1941             verified = mDNSfalse;
1942             goto exit;
1943         }
1944 
1945         if (lcr.r.resrec.RecordType != kDNSRecordTypePacketNegative && lcr.r.resrec.rrtype == kDNSType_TSIG &&
1946             i == msg->h.numAdditionals - 1)
1947         {
1948             hasTSIGAtLast = mDNStrue;
1949         }
1950     }
1951 
1952     if (!hasTSIGAtLast)
1953     {
1954         verified = mDNSfalse;
1955         goto exit;
1956     }
1957 
1958     // Before doing verification, decrement the additional count by 1 (added by the TSIG record)
1959     // Also go back to network byte order.
1960     msg->h.numAdditionals--;
1961     SwapDNSHeaderBytes(msg);
1962 
1963     mDNSu16 rcode;
1964     mDNSu16 tcode;
1965     verified = DNSDigest_VerifyMessage(msg, lastPtr, &lcr, authInfo, &rcode, &tcode);
1966 
1967     // Undo the operation above.
1968     SwapDNSHeaderBytes(msg);
1969     msg->h.numAdditionals++;
1970 
1971 exit:
1972     if (!verified)
1973     {
1974         LogRedact(MDNS_LOG_CATEGORY_DEFAULT, MDNS_LOG_FAULT, "Failed to verify that DNSDigest_VerifyMessage works.");
1975     }
1976     SwapDNSHeaderBytes(msg);
1977 }
1978 
1979 #endif // defined(DEBUG) && DEBUG
1980 
1981 #ifdef __cplusplus
1982 }
1983 #endif
1984