Import OpenSSL 0.9.8a
[dragonfly.git] / crypto / openssl-0.9 / crypto / md32_common.h
1 /* crypto/md32_common.h */
2 /* ====================================================================
3  * Copyright (c) 1999-2002 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  *                      unsigned 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  * HASH_MAKE_STRING
98  *      macro convering context variables to an ASCII hash string.
99  *
100  * Optional macros:
101  *
102  * B_ENDIAN or L_ENDIAN
103  *      defines host byte-order.
104  * HASH_LONG_LOG2
105  *      defaults to 2 if not states otherwise.
106  * HASH_LBLOCK
107  *      assumed to be HASH_CBLOCK/4 if not stated otherwise.
108  * HASH_BLOCK_DATA_ORDER_ALIGNED
109  *      alternative "block" function capable of treating
110  *      aligned input message in original (data) order,
111  *      implemented externally.
112  *
113  * MD5 example:
114  *
115  *      #define DATA_ORDER_IS_LITTLE_ENDIAN
116  *
117  *      #define HASH_LONG               MD5_LONG
118  *      #define HASH_LONG_LOG2          MD5_LONG_LOG2
119  *      #define HASH_CTX                MD5_CTX
120  *      #define HASH_CBLOCK             MD5_CBLOCK
121  *      #define HASH_LBLOCK             MD5_LBLOCK
122  *      #define HASH_UPDATE             MD5_Update
123  *      #define HASH_TRANSFORM          MD5_Transform
124  *      #define HASH_FINAL              MD5_Final
125  *      #define HASH_BLOCK_HOST_ORDER   md5_block_host_order
126  *      #define HASH_BLOCK_DATA_ORDER   md5_block_data_order
127  *
128  *                                      <appro@fy.chalmers.se>
129  */
130
131 #if !defined(DATA_ORDER_IS_BIG_ENDIAN) && !defined(DATA_ORDER_IS_LITTLE_ENDIAN)
132 #error "DATA_ORDER must be defined!"
133 #endif
134
135 #ifndef HASH_CBLOCK
136 #error "HASH_CBLOCK must be defined!"
137 #endif
138 #ifndef HASH_LONG
139 #error "HASH_LONG must be defined!"
140 #endif
141 #ifndef HASH_CTX
142 #error "HASH_CTX must be defined!"
143 #endif
144
145 #ifndef HASH_UPDATE
146 #error "HASH_UPDATE must be defined!"
147 #endif
148 #ifndef HASH_TRANSFORM
149 #error "HASH_TRANSFORM must be defined!"
150 #endif
151 #ifndef HASH_FINAL
152 #error "HASH_FINAL must be defined!"
153 #endif
154
155 #ifndef HASH_BLOCK_HOST_ORDER
156 #error "HASH_BLOCK_HOST_ORDER must be defined!"
157 #endif
158
159 #if 0
160 /*
161  * Moved below as it's required only if HASH_BLOCK_DATA_ORDER_ALIGNED
162  * isn't defined.
163  */
164 #ifndef HASH_BLOCK_DATA_ORDER
165 #error "HASH_BLOCK_DATA_ORDER must be defined!"
166 #endif
167 #endif
168
169 #ifndef HASH_LBLOCK
170 #define HASH_LBLOCK     (HASH_CBLOCK/4)
171 #endif
172
173 #ifndef HASH_LONG_LOG2
174 #define HASH_LONG_LOG2  2
175 #endif
176
177 /*
178  * Engage compiler specific rotate intrinsic function if available.
179  */
180 #undef ROTATE
181 #ifndef PEDANTIC
182 # if defined(_MSC_VER) || defined(__ICC)
183 #  define ROTATE(a,n)   _lrotl(a,n)
184 # elif defined(__MWERKS__)
185 #  if defined(__POWERPC__)
186 #   define ROTATE(a,n)  __rlwinm(a,n,0,31)
187 #  elif defined(__MC68K__)
188     /* Motorola specific tweak. <appro@fy.chalmers.se> */
189 #   define ROTATE(a,n)  ( n<24 ? __rol(a,n) : __ror(a,32-n) )
190 #  else
191 #   define ROTATE(a,n)  __rol(a,n)
192 #  endif
193 # elif defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
194   /*
195    * Some GNU C inline assembler templates. Note that these are
196    * rotates by *constant* number of bits! But that's exactly
197    * what we need here...
198    *                                    <appro@fy.chalmers.se>
199    */
200 #  if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)
201 #   define ROTATE(a,n)  ({ register unsigned int ret;   \
202                                 asm (                   \
203                                 "roll %1,%0"            \
204                                 : "=r"(ret)             \
205                                 : "I"(n), "0"(a)        \
206                                 : "cc");                \
207                            ret;                         \
208                         })
209 #  elif defined(__powerpc) || defined(__ppc__) || defined(__powerpc64__)
210 #   define ROTATE(a,n)  ({ register unsigned int ret;   \
211                                 asm (                   \
212                                 "rlwinm %0,%1,%2,0,31"  \
213                                 : "=r"(ret)             \
214                                 : "r"(a), "I"(n));      \
215                            ret;                         \
216                         })
217 #  endif
218 # endif
219 #endif /* PEDANTIC */
220
221 #if HASH_LONG_LOG2==2   /* Engage only if sizeof(HASH_LONG)== 4 */
222 /* A nice byte order reversal from Wei Dai <weidai@eskimo.com> */
223 #ifdef ROTATE
224 /* 5 instructions with rotate instruction, else 9 */
225 #define REVERSE_FETCH32(a,l)    (                                       \
226                 l=*(const HASH_LONG *)(a),                              \
227                 ((ROTATE(l,8)&0x00FF00FF)|(ROTATE((l&0x00FF00FF),24)))  \
228                                 )
229 #else
230 /* 6 instructions with rotate instruction, else 8 */
231 #define REVERSE_FETCH32(a,l)    (                               \
232                 l=*(const HASH_LONG *)(a),                      \
233                 l=(((l>>8)&0x00FF00FF)|((l&0x00FF00FF)<<8)),    \
234                 ROTATE(l,16)                                    \
235                                 )
236 /*
237  * Originally the middle line started with l=(((l&0xFF00FF00)>>8)|...
238  * It's rewritten as above for two reasons:
239  *      - RISCs aren't good at long constants and have to explicitely
240  *        compose 'em with several (well, usually 2) instructions in a
241  *        register before performing the actual operation and (as you
242  *        already realized:-) having same constant should inspire the
243  *        compiler to permanently allocate the only register for it;
244  *      - most modern CPUs have two ALUs, but usually only one has
245  *        circuitry for shifts:-( this minor tweak inspires compiler
246  *        to schedule shift instructions in a better way...
247  *
248  *                              <appro@fy.chalmers.se>
249  */
250 #endif
251 #endif
252
253 #ifndef ROTATE
254 #define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))
255 #endif
256
257 /*
258  * Make some obvious choices. E.g., HASH_BLOCK_DATA_ORDER_ALIGNED
259  * and HASH_BLOCK_HOST_ORDER ought to be the same if input data
260  * and host are of the same "endianess". It's possible to mask
261  * this with blank #define HASH_BLOCK_DATA_ORDER though...
262  *
263  *                              <appro@fy.chalmers.se>
264  */
265 #if defined(B_ENDIAN)
266 #  if defined(DATA_ORDER_IS_BIG_ENDIAN)
267 #    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
268 #      define HASH_BLOCK_DATA_ORDER_ALIGNED     HASH_BLOCK_HOST_ORDER
269 #    endif
270 #  endif
271 #elif defined(L_ENDIAN)
272 #  if defined(DATA_ORDER_IS_LITTLE_ENDIAN)
273 #    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
274 #      define HASH_BLOCK_DATA_ORDER_ALIGNED     HASH_BLOCK_HOST_ORDER
275 #    endif
276 #  endif
277 #endif
278
279 #if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
280 #ifndef HASH_BLOCK_DATA_ORDER
281 #error "HASH_BLOCK_DATA_ORDER must be defined!"
282 #endif
283 #endif
284
285 #if defined(DATA_ORDER_IS_BIG_ENDIAN)
286
287 #ifndef PEDANTIC
288 # if defined(__GNUC__) && __GNUC__>=2 && !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM)
289 #  if ((defined(__i386) || defined(__i386__)) && !defined(I386_ONLY)) || \
290       (defined(__x86_64) || defined(__x86_64__))
291     /*
292      * This gives ~30-40% performance improvement in SHA-256 compiled
293      * with gcc [on P4]. Well, first macro to be frank. We can pull
294      * this trick on x86* platforms only, because these CPUs can fetch
295      * unaligned data without raising an exception.
296      */
297 #   define HOST_c2l(c,l)        ({ unsigned int r=*((const unsigned int *)(c)); \
298                                    asm ("bswapl %0":"=r"(r):"0"(r));    \
299                                    (c)+=4; (l)=r;                       })
300 #   define HOST_l2c(l,c)        ({ unsigned int r=(l);                  \
301                                    asm ("bswapl %0":"=r"(r):"0"(r));    \
302                                    *((unsigned int *)(c))=r; (c)+=4; r; })
303 #  endif
304 # endif
305 #endif
306
307 #ifndef HOST_c2l
308 #define HOST_c2l(c,l)   (l =(((unsigned long)(*((c)++)))<<24),          \
309                          l|=(((unsigned long)(*((c)++)))<<16),          \
310                          l|=(((unsigned long)(*((c)++)))<< 8),          \
311                          l|=(((unsigned long)(*((c)++)))    ),          \
312                          l)
313 #endif
314 #define HOST_p_c2l(c,l,n)       {                                       \
315                         switch (n) {                                    \
316                         case 0: l =((unsigned long)(*((c)++)))<<24;     \
317                         case 1: l|=((unsigned long)(*((c)++)))<<16;     \
318                         case 2: l|=((unsigned long)(*((c)++)))<< 8;     \
319                         case 3: l|=((unsigned long)(*((c)++)));         \
320                                 } }
321 #define HOST_p_c2l_p(c,l,sc,len) {                                      \
322                         switch (sc) {                                   \
323                         case 0: l =((unsigned long)(*((c)++)))<<24;     \
324                                 if (--len == 0) break;                  \
325                         case 1: l|=((unsigned long)(*((c)++)))<<16;     \
326                                 if (--len == 0) break;                  \
327                         case 2: l|=((unsigned long)(*((c)++)))<< 8;     \
328                                 } }
329 /* NOTE the pointer is not incremented at the end of this */
330 #define HOST_c2l_p(c,l,n)       {                                       \
331                         l=0; (c)+=n;                                    \
332                         switch (n) {                                    \
333                         case 3: l =((unsigned long)(*(--(c))))<< 8;     \
334                         case 2: l|=((unsigned long)(*(--(c))))<<16;     \
335                         case 1: l|=((unsigned long)(*(--(c))))<<24;     \
336                                 } }
337 #ifndef HOST_l2c
338 #define HOST_l2c(l,c)   (*((c)++)=(unsigned char)(((l)>>24)&0xff),      \
339                          *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
340                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
341                          *((c)++)=(unsigned char)(((l)    )&0xff),      \
342                          l)
343 #endif
344
345 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
346
347 #if defined(__i386) || defined(__i386__) || defined(__x86_64) || defined(__x86_64__)
348 # ifndef B_ENDIAN
349    /* See comment in DATA_ORDER_IS_BIG_ENDIAN section. */
350 #  define HOST_c2l(c,l) ((l)=*((const unsigned int *)(c)), (c)+=4, l)
351 #  define HOST_l2c(l,c) (*((unsigned int *)(c))=(l), (c)+=4, l)
352 # endif
353 #endif
354
355 #ifndef HOST_c2l
356 #define HOST_c2l(c,l)   (l =(((unsigned long)(*((c)++)))    ),          \
357                          l|=(((unsigned long)(*((c)++)))<< 8),          \
358                          l|=(((unsigned long)(*((c)++)))<<16),          \
359                          l|=(((unsigned long)(*((c)++)))<<24),          \
360                          l)
361 #endif
362 #define HOST_p_c2l(c,l,n)       {                                       \
363                         switch (n) {                                    \
364                         case 0: l =((unsigned long)(*((c)++)));         \
365                         case 1: l|=((unsigned long)(*((c)++)))<< 8;     \
366                         case 2: l|=((unsigned long)(*((c)++)))<<16;     \
367                         case 3: l|=((unsigned long)(*((c)++)))<<24;     \
368                                 } }
369 #define HOST_p_c2l_p(c,l,sc,len) {                                      \
370                         switch (sc) {                                   \
371                         case 0: l =((unsigned long)(*((c)++)));         \
372                                 if (--len == 0) break;                  \
373                         case 1: l|=((unsigned long)(*((c)++)))<< 8;     \
374                                 if (--len == 0) break;                  \
375                         case 2: l|=((unsigned long)(*((c)++)))<<16;     \
376                                 } }
377 /* NOTE the pointer is not incremented at the end of this */
378 #define HOST_c2l_p(c,l,n)       {                                       \
379                         l=0; (c)+=n;                                    \
380                         switch (n) {                                    \
381                         case 3: l =((unsigned long)(*(--(c))))<<16;     \
382                         case 2: l|=((unsigned long)(*(--(c))))<< 8;     \
383                         case 1: l|=((unsigned long)(*(--(c))));         \
384                                 } }
385 #ifndef HOST_l2c
386 #define HOST_l2c(l,c)   (*((c)++)=(unsigned char)(((l)    )&0xff),      \
387                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
388                          *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
389                          *((c)++)=(unsigned char)(((l)>>24)&0xff),      \
390                          l)
391 #endif
392
393 #endif
394
395 /*
396  * Time for some action:-)
397  */
398
399 int HASH_UPDATE (HASH_CTX *c, const void *data_, size_t len)
400         {
401         const unsigned char *data=data_;
402         register HASH_LONG * p;
403         register HASH_LONG l;
404         size_t sw,sc,ew,ec;
405
406         if (len==0) return 1;
407
408         l=(c->Nl+(((HASH_LONG)len)<<3))&0xffffffffUL;
409         /* 95-05-24 eay Fixed a bug with the overflow handling, thanks to
410          * Wei Dai <weidai@eskimo.com> for pointing it out. */
411         if (l < c->Nl) /* overflow */
412                 c->Nh++;
413         c->Nh+=(len>>29);       /* might cause compiler warning on 16-bit */
414         c->Nl=l;
415
416         if (c->num != 0)
417                 {
418                 p=c->data;
419                 sw=c->num>>2;
420                 sc=c->num&0x03;
421
422                 if ((c->num+len) >= HASH_CBLOCK)
423                         {
424                         l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l;
425                         for (; sw<HASH_LBLOCK; sw++)
426                                 {
427                                 HOST_c2l(data,l); p[sw]=l;
428                                 }
429                         HASH_BLOCK_HOST_ORDER (c,p,1);
430                         len-=(HASH_CBLOCK-c->num);
431                         c->num=0;
432                         /* drop through and do the rest */
433                         }
434                 else
435                         {
436                         c->num+=(unsigned int)len;
437                         if ((sc+len) < 4) /* ugly, add char's to a word */
438                                 {
439                                 l=p[sw]; HOST_p_c2l_p(data,l,sc,len); p[sw]=l;
440                                 }
441                         else
442                                 {
443                                 ew=(c->num>>2);
444                                 ec=(c->num&0x03);
445                                 if (sc)
446                                         l=p[sw];
447                                 HOST_p_c2l(data,l,sc);
448                                 p[sw++]=l;
449                                 for (; sw < ew; sw++)
450                                         {
451                                         HOST_c2l(data,l); p[sw]=l;
452                                         }
453                                 if (ec)
454                                         {
455                                         HOST_c2l_p(data,l,ec); p[sw]=l;
456                                         }
457                                 }
458                         return 1;
459                         }
460                 }
461
462         sw=len/HASH_CBLOCK;
463         if (sw > 0)
464                 {
465 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
466                 /*
467                  * Note that HASH_BLOCK_DATA_ORDER_ALIGNED gets defined
468                  * only if sizeof(HASH_LONG)==4.
469                  */
470                 if ((((size_t)data)%4) == 0)
471                         {
472                         /* data is properly aligned so that we can cast it: */
473                         HASH_BLOCK_DATA_ORDER_ALIGNED (c,(const HASH_LONG *)data,sw);
474                         sw*=HASH_CBLOCK;
475                         data+=sw;
476                         len-=sw;
477                         }
478                 else
479 #if !defined(HASH_BLOCK_DATA_ORDER)
480                         while (sw--)
481                                 {
482                                 memcpy (p=c->data,data,HASH_CBLOCK);
483                                 HASH_BLOCK_DATA_ORDER_ALIGNED(c,p,1);
484                                 data+=HASH_CBLOCK;
485                                 len-=HASH_CBLOCK;
486                                 }
487 #endif
488 #endif
489 #if defined(HASH_BLOCK_DATA_ORDER)
490                         {
491                         HASH_BLOCK_DATA_ORDER(c,data,sw);
492                         sw*=HASH_CBLOCK;
493                         data+=sw;
494                         len-=sw;
495                         }
496 #endif
497                 }
498
499         if (len!=0)
500                 {
501                 p = c->data;
502                 c->num = len;
503                 ew=len>>2;      /* words to copy */
504                 ec=len&0x03;
505                 for (; ew; ew--,p++)
506                         {
507                         HOST_c2l(data,l); *p=l;
508                         }
509                 HOST_c2l_p(data,l,ec);
510                 *p=l;
511                 }
512         return 1;
513         }
514
515
516 void HASH_TRANSFORM (HASH_CTX *c, const unsigned char *data)
517         {
518 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
519         if ((((size_t)data)%4) == 0)
520                 /* data is properly aligned so that we can cast it: */
521                 HASH_BLOCK_DATA_ORDER_ALIGNED (c,(const HASH_LONG *)data,1);
522         else
523 #if !defined(HASH_BLOCK_DATA_ORDER)
524                 {
525                 memcpy (c->data,data,HASH_CBLOCK);
526                 HASH_BLOCK_DATA_ORDER_ALIGNED (c,c->data,1);
527                 }
528 #endif
529 #endif
530 #if defined(HASH_BLOCK_DATA_ORDER)
531         HASH_BLOCK_DATA_ORDER (c,data,1);
532 #endif
533         }
534
535
536 int HASH_FINAL (unsigned char *md, HASH_CTX *c)
537         {
538         register HASH_LONG *p;
539         register unsigned long l;
540         register int i,j;
541         static const unsigned char end[4]={0x80,0x00,0x00,0x00};
542         const unsigned char *cp=end;
543
544         /* c->num should definitly have room for at least one more byte. */
545         p=c->data;
546         i=c->num>>2;
547         j=c->num&0x03;
548
549 #if 0
550         /* purify often complains about the following line as an
551          * Uninitialized Memory Read.  While this can be true, the
552          * following p_c2l macro will reset l when that case is true.
553          * This is because j&0x03 contains the number of 'valid' bytes
554          * already in p[i].  If and only if j&0x03 == 0, the UMR will
555          * occur but this is also the only time p_c2l will do
556          * l= *(cp++) instead of l|= *(cp++)
557          * Many thanks to Alex Tang <altitude@cic.net> for pickup this
558          * 'potential bug' */
559 #ifdef PURIFY
560         if (j==0) p[i]=0; /* Yeah, but that's not the way to fix it:-) */
561 #endif
562         l=p[i];
563 #else
564         l = (j==0) ? 0 : p[i];
565 #endif
566         HOST_p_c2l(cp,l,j); p[i++]=l; /* i is the next 'undefined word' */
567
568         if (i>(HASH_LBLOCK-2)) /* save room for Nl and Nh */
569                 {
570                 if (i<HASH_LBLOCK) p[i]=0;
571                 HASH_BLOCK_HOST_ORDER (c,p,1);
572                 i=0;
573                 }
574         for (; i<(HASH_LBLOCK-2); i++)
575                 p[i]=0;
576
577 #if   defined(DATA_ORDER_IS_BIG_ENDIAN)
578         p[HASH_LBLOCK-2]=c->Nh;
579         p[HASH_LBLOCK-1]=c->Nl;
580 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
581         p[HASH_LBLOCK-2]=c->Nl;
582         p[HASH_LBLOCK-1]=c->Nh;
583 #endif
584         HASH_BLOCK_HOST_ORDER (c,p,1);
585
586 #ifndef HASH_MAKE_STRING
587 #error "HASH_MAKE_STRING must be defined!"
588 #else
589         HASH_MAKE_STRING(c,md);
590 #endif
591
592         c->num=0;
593         /* clear stuff, HASH_BLOCK may be leaving some stuff on the stack
594          * but I'm not worried :-)
595         OPENSSL_cleanse((void *)c,sizeof(HASH_CTX));
596          */
597         return 1;
598         }
599
600 #ifndef MD32_REG_T
601 #define MD32_REG_T long
602 /*
603  * This comment was originaly written for MD5, which is why it
604  * discusses A-D. But it basically applies to all 32-bit digests,
605  * which is why it was moved to common header file.
606  *
607  * In case you wonder why A-D are declared as long and not
608  * as MD5_LONG. Doing so results in slight performance
609  * boost on LP64 architectures. The catch is we don't
610  * really care if 32 MSBs of a 64-bit register get polluted
611  * with eventual overflows as we *save* only 32 LSBs in
612  * *either* case. Now declaring 'em long excuses the compiler
613  * from keeping 32 MSBs zeroed resulting in 13% performance
614  * improvement under SPARC Solaris7/64 and 5% under AlphaLinux.
615  * Well, to be honest it should say that this *prevents* 
616  * performance degradation.
617  *                              <appro@fy.chalmers.se>
618  * Apparently there're LP64 compilers that generate better
619  * code if A-D are declared int. Most notably GCC-x86_64
620  * generates better code.
621  *                              <appro@fy.chalmers.se>
622  */
623 #endif