Get rid of casts.
[openssl.git] / crypto / md32_common.h
1 /* crypto/md32_common.h */
2 /* ====================================================================
3  * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer. 
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in
14  *    the documentation and/or other materials provided with the
15  *    distribution.
16  *
17  * 3. All advertising materials mentioning features or use of this
18  *    software must display the following acknowledgment:
19  *    "This product includes software developed by the OpenSSL Project
20  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
21  *
22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23  *    endorse or promote products derived from this software without
24  *    prior written permission. For written permission, please contact
25  *    licensing@OpenSSL.org.
26  *
27  * 5. Products derived from this software may not be called "OpenSSL"
28  *    nor may "OpenSSL" appear in their names without prior written
29  *    permission of the OpenSSL Project.
30  *
31  * 6. Redistributions of any form whatsoever must retain the following
32  *    acknowledgment:
33  *    "This product includes software developed by the OpenSSL Project
34  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47  * OF THE POSSIBILITY OF SUCH DAMAGE.
48  * ====================================================================
49  *
50  * This product includes cryptographic software written by Eric Young
51  * (eay@cryptsoft.com).  This product includes software written by Tim
52  * Hudson (tjh@cryptsoft.com).
53  *
54  */
55
56 /*
57  * This is a generic 32 bit "collector" for message digest algorithms.
58  * Whenever needed it collects input character stream into chunks of
59  * 32 bit values and invokes a block function that performs actual hash
60  * calculations.
61  *
62  * Porting guide.
63  *
64  * Obligatory macros:
65  *
66  * DATA_ORDER_IS_BIG_ENDIAN or DATA_ORDER_IS_LITTLE_ENDIAN
67  *      this macro defines byte order of input stream.
68  * HASH_CBLOCK
69  *      size of a unit chunk HASH_BLOCK operates on.
70  * HASH_LONG
71  *      has to be at lest 32 bit wide, if it's wider, then
72  *      HASH_LONG_LOG2 *has to* be defined along
73  * HASH_CTX
74  *      context structure that at least contains following
75  *      members:
76  *              typedef struct {
77  *                      ...
78  *                      HASH_LONG       Nl,Nh;
79  *                      HASH_LONG       data[HASH_LBLOCK];
80  *                      int             num;
81  *                      ...
82  *                      } HASH_CTX;
83  * HASH_UPDATE
84  *      name of "Update" function, implemented here.
85  * HASH_TRANSFORM
86  *      name of "Transform" function, implemented here.
87  * HASH_FINAL
88  *      name of "Final" function, implemented here.
89  * HASH_BLOCK_HOST_ORDER
90  *      name of "block" function treating *aligned* input message
91  *      in host byte order, implemented externally.
92  * HASH_BLOCK_DATA_ORDER
93  *      name of "block" function treating *unaligned* input message
94  *      in original (data) byte order, implemented externally (it
95  *      actually is optional if data and host are of the same
96  *      "endianess").
97  *
98  * Optional macros:
99  *
100  * B_ENDIAN or L_ENDIAN
101  *      defines host byte-order.
102  * HASH_LONG_LOG2
103  *      defaults to 2 if not states otherwise.
104  * HASH_LBLOCK
105  *      assumed to be HASH_CBLOCK/4 if not stated otherwise.
106  * HASH_BLOCK_DATA_ORDER_ALIGNED
107  *      alternative "block" function capable of treating
108  *      aligned input message in original (data) order,
109  *      implemented externally.
110  *
111  * MD5 example:
112  *
113  *      #define DATA_ORDER_IS_LITTLE_ENDIAN
114  *
115  *      #define HASH_LONG               MD5_LONG
116  *      #define HASH_LONG_LOG2          MD5_LONG_LOG2
117  *      #define HASH_CTX                MD5_CTX
118  *      #define HASH_CBLOCK             MD5_CBLOCK
119  *      #define HASH_LBLOCK             MD5_LBLOCK
120  *      #define HASH_UPDATE             MD5_Update
121  *      #define HASH_TRANSFORM          MD5_Transform
122  *      #define HASH_FINAL              MD5_Final
123  *      #define HASH_BLOCK_HOST_ORDER   md5_block_host_order
124  *      #define HASH_BLOCK_DATA_ORDER   md5_block_data_order
125  *
126  *                                      <appro@fy.chalmers.se>
127  */
128
129 #if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN)
130 #error "DATA_ORDER must be defined!"
131 #endif
132
133 #ifndef HASH_CBLOCK
134 #error "HASH_CBLOCK must be defined!"
135 #endif
136 #ifndef HASH_LONG
137 #error "HASH_LONG must be defined!"
138 #endif
139 #ifndef HASH_CTX
140 #error "HASH_CTX must be defined!"
141 #endif
142
143 #ifndef HASH_UPDATE
144 #error "HASH_UPDATE must be defined!"
145 #endif
146 #ifndef HASH_TRANSFORM
147 #error "HASH_TRANSFORM must be defined!"
148 #endif
149 #ifndef HASH_FINAL
150 #error "HASH_FINAL must be defined!"
151 #endif
152
153 #ifndef HASH_BLOCK_HOST_ORDER
154 #error "HASH_BLOCK_HOST_ORDER must be defined!"
155 #endif
156
157 #if 0
158 /*
159  * Moved below as it's required only if HASH_BLOCK_DATA_ORDER_ALIGNED
160  * isn't defined.
161  */
162 #ifndef HASH_BLOCK_DATA_ORDER
163 #error "HASH_BLOCK_DATA_ORDER must be defined!"
164 #endif
165 #endif
166
167 #ifndef HASH_LBLOCK
168 #define HASH_LBLOCK     (HASH_CBLOCK/4)
169 #endif
170
171 #ifndef HASH_LONG_LOG2
172 #define HASH_LONG_LOG2  2
173 #endif
174
175 /*
176  * Engage compiler specific rotate intrinsic function if available.
177  */
178 #undef ROTATE
179 #ifndef PEDANTIC
180 # if defined(_MSC_VER)
181 #  define ROTATE(a,n)     _lrotl(a,n)
182 # elif defined(__GNUC__) && __GNUC__>=2
183   /*
184    * Some GNU C inline assembler templates. Note that these are
185    * rotates by *constant* number of bits! But that's exactly
186    * what we need here...
187    *
188    *                                    <appro@fy.chalmers.se>
189    */
190 #  if defined(__i386)
191 #   define ROTATE(a,n)  ({ register unsigned int ret;   \
192                                 asm volatile (          \
193                                 "roll %1,%0"            \
194                                 : "=r"(ret)             \
195                                 : "I"(n), "0"(a)        \
196                                 : "cc");                \
197                            ret;                         \
198                         })
199 #  elif defined(__powerpc)
200 #   define ROTATE(a,n)  ({ register unsigned int ret;   \
201                                 asm volatile (          \
202                                 "rlwinm %0,%1,%2,0,31"  \
203                                 : "=r"(ret)             \
204                                 : "r"(a), "I"(n));      \
205                            ret;                         \
206                         })
207 #  endif
208 # endif
209
210 /*
211  * Engage compiler specific "fetch in reverse byte order"
212  * intrinsic function if available.
213  */
214 # if defined(__GNUC__) && __GNUC__>=2
215   /* some GNU C inline assembler templates by <appro@fy.chalmers.se> */
216 #  if defined(__i386) && !defined(I386_ONLY)
217 #   define BE_FETCH32(a)        ({ register unsigned int l=(a);\
218                                 asm volatile (          \
219                                 "bswapl %0"             \
220                                 : "=r"(l) : "0"(l));    \
221                           l;                            \
222                         })
223 #  elif defined(__powerpc)
224 #   define LE_FETCH32(a)        ({ register unsigned int l;     \
225                                 asm volatile (          \
226                                 "lwbrx %0,0,%1"         \
227                                 : "=r"(l)               \
228                                 : "r"(a));              \
229                            l;                           \
230                         })
231
232 #  elif defined(__sparc) && defined(ULTRASPARC)
233 #  define LE_FETCH32(a) ({ register unsigned int l;             \
234                                 asm volatile (                  \
235                                 "lda [%1]#ASI_PRIMARY_LITTLE,%0"\
236                                 : "=r"(l)                       \
237                                 : "r"(a));                      \
238                            l;                                   \
239                         })
240 #  endif
241 # endif
242 #endif /* PEDANTIC */
243
244 #if HASH_LONG_LOG2==2   /* Engage only if sizeof(HASH_LONG)== 4 */
245 /* A nice byte order reversal from Wei Dai <weidai@eskimo.com> */
246 #ifdef ROTATE
247 /* 5 instructions with rotate instruction, else 9 */
248 #define REVERSE_FETCH32(a,l)    (                                       \
249                 l=*(const HASH_LONG *)(a),                              \
250                 ((ROTATE(l,8)&0x00FF00FF)|(ROTATE((l&0x00FF00FF),24)))  \
251                                 )
252 #else
253 /* 6 instructions with rotate instruction, else 8 */
254 #define REVERSE_FETCH32(a,l)    (                               \
255                 l=*(const HASH_LONG *)(a),                      \
256                 l=(((l>>8)&0x00FF00FF)|((l&0x00FF00FF)<<8)),    \
257                 ROTATE(l,16)                                    \
258                                 )
259 /*
260  * Originally the middle line started with l=(((l&0xFF00FF00)>>8)|...
261  * It's rewritten as above for two reasons:
262  *      - RISCs aren't good at long constants and have to explicitely
263  *        compose 'em with several (well, usually 2) instructions in a
264  *        register before performing the actual operation and (as you
265  *        already realized:-) having same constant should inspire the
266  *        compiler to permanently allocate the only register for it;
267  *      - most modern CPUs have two ALUs, but usually only one has
268  *        circuitry for shifts:-( this minor tweak inspires compiler
269  *        to schedule shift instructions in a better way...
270  *
271  *                              <appro@fy.chalmers.se>
272  */
273 #endif
274 #endif
275
276 #ifndef ROTATE
277 #define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))
278 #endif
279
280 /*
281  * Make some obvious choices. E.g., HASH_BLOCK_DATA_ORDER_ALIGNED
282  * and HASH_BLOCK_HOST_ORDER ought to be the same if input data
283  * and host are of the same "endianess". It's possible to mask
284  * this with blank #define HASH_BLOCK_DATA_ORDER though...
285  *
286  *                              <appro@fy.chalmers.se>
287  */
288 #if defined(B_ENDIAN)
289 #  if defined(DATA_ORDER_IS_BIG_ENDIAN)
290 #    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
291 #      define HASH_BLOCK_DATA_ORDER_ALIGNED     HASH_BLOCK_HOST_ORDER
292 #    endif
293 #  elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
294 #    ifndef HOST_FETCH32
295 #      ifdef LE_FETCH32
296 #        define HOST_FETCH32(p,l)       LE_FETCH32(p)
297 #      elif defined(REVERSE_FETCH32)
298 #        define HOST_FETCH32(p,l)       REVERSE_FETCH32(p,l)
299 #      endif
300 #    endif
301 #  endif
302 #elif defined(L_ENDIAN)
303 #  if defined(DATA_ORDER_IS_LITTLE_ENDIAN)
304 #    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
305 #      define HASH_BLOCK_DATA_ORDER_ALIGNED     HASH_BLOCK_HOST_ORDER
306 #    endif
307 #  elif defined(DATA_ORDER_IS_BIG_ENDIAN)
308 #    ifndef HOST_FETCH32
309 #      ifdef BE_FETCH32
310 #        define HOST_FETCH32(p,l)       BE_FETCH32(p)
311 #      elif defined(REVERSE_FETCH32)
312 #        define HOST_FETCH32(p,l)       REVERSE_FETCH32(p,l)
313 #      endif
314 #    endif
315 #  endif
316 #endif
317
318 #if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_BLOCK_DATA_ORDER_ALIGNED!=1
319 #ifndef HASH_BLOCK_DATA_ORDER
320 #error "HASH_BLOCK_DATA_ORDER must be defined!"
321 #endif
322 #endif
323
324 #if defined(DATA_ORDER_IS_BIG_ENDIAN)
325
326 #define HOST_c2l(c,l)   (l =(((unsigned long)(*((c)++)))<<24),          \
327                          l|=(((unsigned long)(*((c)++)))<<16),          \
328                          l|=(((unsigned long)(*((c)++)))<< 8),          \
329                          l|=(((unsigned long)(*((c)++)))    ),          \
330                          l)
331 #define HOST_p_c2l(c,l,n)       {                                       \
332                         switch (n) {                                    \
333                         case 0: l =((unsigned long)(*((c)++)))<<24;     \
334                         case 1: l|=((unsigned long)(*((c)++)))<<16;     \
335                         case 2: l|=((unsigned long)(*((c)++)))<< 8;     \
336                         case 3: l|=((unsigned long)(*((c)++)));         \
337                                 } }
338 #define HOST_p_c2l_p(c,l,sc,len) {                                      \
339                         switch (sc) {                                   \
340                         case 0: l =((unsigned long)(*((c)++)))<<24;     \
341                                 if (--len == 0) break;                  \
342                         case 1: l|=((unsigned long)(*((c)++)))<<16;     \
343                                 if (--len == 0) break;                  \
344                         case 2: l|=((unsigned long)(*((c)++)))<< 8;     \
345                                 } }
346 /* NOTE the pointer is not incremented at the end of this */
347 #define HOST_c2l_p(c,l,n)       {                                       \
348                         l=0; (c)+=n;                                    \
349                         switch (n) {                                    \
350                         case 3: l =((unsigned long)(*(--(c))))<< 8;     \
351                         case 2: l|=((unsigned long)(*(--(c))))<<16;     \
352                         case 1: l|=((unsigned long)(*(--(c))))<<24;     \
353                                 } }
354 #define HOST_l2c(l,c)   (*((c)++)=(unsigned char)(((l)>>24)&0xff),      \
355                          *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
356                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
357                          *((c)++)=(unsigned char)(((l)    )&0xff),      \
358                          l)
359
360 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
361
362 #define HOST_c2l(c,l)   (l =(((unsigned long)(*((c)++)))    ),          \
363                          l|=(((unsigned long)(*((c)++)))<< 8),          \
364                          l|=(((unsigned long)(*((c)++)))<<16),          \
365                          l|=(((unsigned long)(*((c)++)))<<24),          \
366                          l)
367 #define HOST_p_c2l(c,l,n)       {                                       \
368                         switch (n) {                                    \
369                         case 0: l =((unsigned long)(*((c)++)));         \
370                         case 1: l|=((unsigned long)(*((c)++)))<< 8;     \
371                         case 2: l|=((unsigned long)(*((c)++)))<<16;     \
372                         case 3: l|=((unsigned long)(*((c)++)))<<24;     \
373                                 } }
374 #define HOST_p_c2l_p(c,l,sc,len) {                                      \
375                         switch (sc) {                                   \
376                         case 0: l =((unsigned long)(*((c)++)));         \
377                                 if (--len == 0) break;                  \
378                         case 1: l|=((unsigned long)(*((c)++)))<< 8;     \
379                                 if (--len == 0) break;                  \
380                         case 2: l|=((unsigned long)(*((c)++)))<<16;     \
381                                 } }
382 /* NOTE the pointer is not incremented at the end of this */
383 #define HOST_c2l_p(c,l,n)       {                                       \
384                         l=0; (c)+=n;                                    \
385                         switch (n) {                                    \
386                         case 3: l =((unsigned long)(*(--(c))))<<16;     \
387                         case 2: l|=((unsigned long)(*(--(c))))<< 8;     \
388                         case 1: l|=((unsigned long)(*(--(c))));         \
389                                 } }
390 #define HOST_l2c(l,c)   (*((c)++)=(unsigned char)(((l)    )&0xff),      \
391                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
392                          *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
393                          *((c)++)=(unsigned char)(((l)>>24)&0xff),      \
394                          l)
395
396 #endif
397
398 /*
399  * Time for some action:-)
400  */
401
402 void HASH_UPDATE (HASH_CTX *c, const unsigned char *data, unsigned long len)
403         {
404         register HASH_LONG * p;
405         register unsigned long l;
406         int sw,sc,ew,ec;
407
408         if (len==0) return;
409
410         l=(c->Nl+(len<<3))&0xffffffffL;
411         /* 95-05-24 eay Fixed a bug with the overflow handling, thanks to
412          * Wei Dai <weidai@eskimo.com> for pointing it out. */
413         if (l < c->Nl) /* overflow */
414                 c->Nh++;
415         c->Nh+=(len>>29);
416         c->Nl=l;
417
418         if (c->num != 0)
419                 {
420                 p=c->data;
421                 sw=c->num>>2;
422                 sc=c->num&0x03;
423
424                 if ((c->num+len) >= HASH_CBLOCK)
425                         {
426                         l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l;
427                         for (; sw<HASH_LBLOCK; sw++)
428                                 {
429                                 HOST_c2l(data,l); p[sw]=l;
430                                 }
431                         HASH_BLOCK_HOST_ORDER (c,p,1);
432                         len-=(HASH_CBLOCK-c->num);
433                         c->num=0;
434                         /* drop through and do the rest */
435                         }
436                 else
437                         {
438                         c->num+=len;
439                         if ((sc+len) < 4) /* ugly, add char's to a word */
440                                 {
441                                 l=p[sw]; HOST_p_c2l_p(data,l,sc,len); p[sw]=l;
442                                 }
443                         else
444                                 {
445                                 ew=(c->num>>2);
446                                 ec=(c->num&0x03);
447                                 l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l;
448                                 for (; sw < ew; sw++)
449                                         {
450                                         HOST_c2l(data,l); p[sw]=l;
451                                         }
452                                 if (ec)
453                                         {
454                                         HOST_c2l_p(data,l,ec); p[sw]=l;
455                                         }
456                                 }
457                         return;
458                         }
459                 }
460
461         sw=len/HASH_CBLOCK;
462         if (sw > 0)
463                 {
464 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_BLOCK_DATA_ORDER_ALIGNED!=1
465                 /*
466                  * Note that HASH_BLOCK_DATA_ORDER_ALIGNED gets defined
467                  * only if sizeof(HASH_LONG)==4.
468                  */
469                 if ((((unsigned long)data)%4) == 0)
470                         {
471                         HASH_BLOCK_DATA_ORDER_ALIGNED (c,data,sw);
472                         sw*=HASH_CBLOCK;
473                         data+=sw;
474                         len-=sw;
475                         }
476                 else
477 #if !defined(HASH_BLOCK_DATA_ORDER)
478                         while (sw--)
479                                 {
480                                 memcpy (p=c->data,data,HASH_CBLOCK);
481                                 HASH_BLOCK_DATA_ORDER_ALIGNED(c,p,1);
482                                 data+=HASH_CBLOCK;
483                                 len-=HASH_CBLOCK;
484                                 }
485 #endif
486 #endif
487 #if defined(HASH_BLOCK_DATA_ORDER)
488                         {
489                         HASH_BLOCK_DATA_ORDER(c,data,sw);
490                         sw*=HASH_CBLOCK;
491                         data+=sw;
492                         len-=sw;
493                         }
494 #endif
495                 }
496
497         if (len!=0)
498                 {
499                 p = c->data;
500                 c->num = len;
501                 ew=len>>2;      /* words to copy */
502                 ec=len&0x03;
503                 for (; ew; ew--,p++)
504                         {
505                         HOST_c2l(data,l); *p=l;
506                         }
507                 HOST_c2l_p(data,l,ec);
508                 *p=l;
509                 }
510         }
511
512
513 void HASH_TRANSFORM (HASH_CTX *c, const unsigned char *data)
514         {
515 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_BLOCK_DATA_ORDER_ALIGNED!=1
516         if ((((unsigned long)data)%4) == 0)
517                 HASH_BLOCK_DATA_ORDER_ALIGNED (c,data,1);
518         else
519 #if !defined(HASH_BLOCK_DATA_ORDER)
520                 {
521                 memcpy (c->data,data,HASH_CBLOCK);
522                 HASH_BLOCK_DATA_ORDER_ALIGNED (c,c->data,1);
523                 }
524 #endif
525 #endif
526 #if defined(HASH_BLOCK_DATA_ORDER)
527         HASH_BLOCK_DATA_ORDER (c,data,1);
528 #endif
529         }
530
531
532 void HASH_FINAL (unsigned char *md, HASH_CTX *c)
533         {
534         register HASH_LONG *p;
535         register unsigned long l;
536         register int i,j;
537         static const unsigned char end[4]={0x80,0x00,0x00,0x00};
538         const unsigned char *cp=end;
539
540         /* c->num should definitly have room for at least one more byte. */
541         p=c->data;
542         i=c->num>>2;
543         j=c->num&0x03;
544
545 #if 0
546         /* purify often complains about the following line as an
547          * Uninitialized Memory Read.  While this can be true, the
548          * following p_c2l macro will reset l when that case is true.
549          * This is because j&0x03 contains the number of 'valid' bytes
550          * already in p[i].  If and only if j&0x03 == 0, the UMR will
551          * occur but this is also the only time p_c2l will do
552          * l= *(cp++) instead of l|= *(cp++)
553          * Many thanks to Alex Tang <altitude@cic.net> for pickup this
554          * 'potential bug' */
555 #ifdef PURIFY
556         if (j==0) p[i]=0; /* Yeah, but that's not the way to fix it:-) */
557 #endif
558         l=p[i];
559 #else
560         l = (j==0) ? 0 : p[i];
561 #endif
562         HOST_p_c2l(cp,l,j); p[i++]=l; /* i is the next 'undefined word' */
563
564         if (i>(HASH_LBLOCK-2)) /* save room for Nl and Nh */
565                 {
566                 if (i<HASH_LBLOCK) p[i]=0;
567                 HASH_BLOCK_HOST_ORDER (c,p,1);
568                 i=0;
569                 }
570         for (; i<(HASH_LBLOCK-2); i++)
571                 p[i]=0;
572
573 #if   defined(DATA_ORDER_IS_BIG_ENDIAN)
574         p[HASH_LBLOCK-2]=c->Nh;
575         p[HASH_LBLOCK-1]=c->Nl;
576 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
577         p[HASH_LBLOCK-2]=c->Nl;
578         p[HASH_LBLOCK-1]=c->Nh;
579 #endif
580         HASH_BLOCK_HOST_ORDER (c,p,1);
581
582         l=c->A; HOST_l2c(l,md);
583         l=c->B; HOST_l2c(l,md);
584         l=c->C; HOST_l2c(l,md);
585         l=c->D; HOST_l2c(l,md);
586
587         c->num=0;
588         /* clear stuff, HASH_BLOCK may be leaving some stuff on the stack
589          * but I'm not worried :-)
590         memset((void *)c,0,sizeof(HASH_CTX));
591          */
592         }