470a8c3e512175a27554a7dff288085049399f63
[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  * 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)
183 #  define ROTATE(a,n)   _lrotl(a,n)
184 # elif defined(__MWERKS__)
185 #  ifdef __POWERPC__
186 #   define ROTATE(a,n)  __rlwinm(a,n,0,31)
187 #  else
188 #   define ROTATE(a,n)  __rol(a,n)
189 #  endif
190 # elif defined(__GNUC__) && __GNUC__>=2 && !defined(NO_ASM)
191   /*
192    * Some GNU C inline assembler templates. Note that these are
193    * rotates by *constant* number of bits! But that's exactly
194    * what we need here...
195    *
196    *                                    <appro@fy.chalmers.se>
197    */
198 #  if defined(__i386)
199 #   define ROTATE(a,n)  ({ register unsigned int ret;   \
200                                 asm volatile (          \
201                                 "roll %1,%0"            \
202                                 : "=r"(ret)             \
203                                 : "I"(n), "0"(a)        \
204                                 : "cc");                \
205                            ret;                         \
206                         })
207 #  elif defined(__powerpc)
208 #   define ROTATE(a,n)  ({ register unsigned int ret;   \
209                                 asm volatile (          \
210                                 "rlwinm %0,%1,%2,0,31"  \
211                                 : "=r"(ret)             \
212                                 : "r"(a), "I"(n));      \
213                            ret;                         \
214                         })
215 #  endif
216 # endif
217
218 /*
219  * Engage compiler specific "fetch in reverse byte order"
220  * intrinsic function if available.
221  */
222 # if defined(__GNUC__) && __GNUC__>=2 && !defined(NO_ASM)
223   /* some GNU C inline assembler templates by <appro@fy.chalmers.se> */
224 #  if defined(__i386) && !defined(I386_ONLY)
225 #   define BE_FETCH32(a)        ({ register unsigned int l=(a);\
226                                 asm volatile (          \
227                                 "bswapl %0"             \
228                                 : "=r"(l) : "0"(l));    \
229                           l;                            \
230                         })
231 #  elif defined(__powerpc)
232 #   define LE_FETCH32(a)        ({ register unsigned int l;     \
233                                 asm volatile (          \
234                                 "lwbrx %0,0,%1"         \
235                                 : "=r"(l)               \
236                                 : "r"(a));              \
237                            l;                           \
238                         })
239
240 #  elif defined(__sparc) && defined(ULTRASPARC)
241 #  define LE_FETCH32(a) ({ register unsigned int l;             \
242                                 asm volatile (                  \
243                                 "lda [%1]#ASI_PRIMARY_LITTLE,%0"\
244                                 : "=r"(l)                       \
245                                 : "r"(a));                      \
246                            l;                                   \
247                         })
248 #  endif
249 # endif
250 #endif /* PEDANTIC */
251
252 #if HASH_LONG_LOG2==2   /* Engage only if sizeof(HASH_LONG)== 4 */
253 /* A nice byte order reversal from Wei Dai <weidai@eskimo.com> */
254 #ifdef ROTATE
255 /* 5 instructions with rotate instruction, else 9 */
256 #define REVERSE_FETCH32(a,l)    (                                       \
257                 l=*(const HASH_LONG *)(a),                              \
258                 ((ROTATE(l,8)&0x00FF00FF)|(ROTATE((l&0x00FF00FF),24)))  \
259                                 )
260 #else
261 /* 6 instructions with rotate instruction, else 8 */
262 #define REVERSE_FETCH32(a,l)    (                               \
263                 l=*(const HASH_LONG *)(a),                      \
264                 l=(((l>>8)&0x00FF00FF)|((l&0x00FF00FF)<<8)),    \
265                 ROTATE(l,16)                                    \
266                                 )
267 /*
268  * Originally the middle line started with l=(((l&0xFF00FF00)>>8)|...
269  * It's rewritten as above for two reasons:
270  *      - RISCs aren't good at long constants and have to explicitely
271  *        compose 'em with several (well, usually 2) instructions in a
272  *        register before performing the actual operation and (as you
273  *        already realized:-) having same constant should inspire the
274  *        compiler to permanently allocate the only register for it;
275  *      - most modern CPUs have two ALUs, but usually only one has
276  *        circuitry for shifts:-( this minor tweak inspires compiler
277  *        to schedule shift instructions in a better way...
278  *
279  *                              <appro@fy.chalmers.se>
280  */
281 #endif
282 #endif
283
284 #ifndef ROTATE
285 #define ROTATE(a,n)     (((a)<<(n))|(((a)&0xffffffff)>>(32-(n))))
286 #endif
287
288 /*
289  * Make some obvious choices. E.g., HASH_BLOCK_DATA_ORDER_ALIGNED
290  * and HASH_BLOCK_HOST_ORDER ought to be the same if input data
291  * and host are of the same "endianess". It's possible to mask
292  * this with blank #define HASH_BLOCK_DATA_ORDER though...
293  *
294  *                              <appro@fy.chalmers.se>
295  */
296 #if defined(B_ENDIAN)
297 #  if defined(DATA_ORDER_IS_BIG_ENDIAN)
298 #    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
299 #      define HASH_BLOCK_DATA_ORDER_ALIGNED     HASH_BLOCK_HOST_ORDER
300 #    endif
301 #  elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
302 #    ifndef HOST_FETCH32
303 #      ifdef LE_FETCH32
304 #        define HOST_FETCH32(p,l)       LE_FETCH32(p)
305 #      elif defined(REVERSE_FETCH32)
306 #        define HOST_FETCH32(p,l)       REVERSE_FETCH32(p,l)
307 #      endif
308 #    endif
309 #  endif
310 #elif defined(L_ENDIAN)
311 #  if defined(DATA_ORDER_IS_LITTLE_ENDIAN)
312 #    if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED) && HASH_LONG_LOG2==2
313 #      define HASH_BLOCK_DATA_ORDER_ALIGNED     HASH_BLOCK_HOST_ORDER
314 #    endif
315 #  elif defined(DATA_ORDER_IS_BIG_ENDIAN)
316 #    ifndef HOST_FETCH32
317 #      ifdef BE_FETCH32
318 #        define HOST_FETCH32(p,l)       BE_FETCH32(p)
319 #      elif defined(REVERSE_FETCH32)
320 #        define HOST_FETCH32(p,l)       REVERSE_FETCH32(p,l)
321 #      endif
322 #    endif
323 #  endif
324 #endif
325
326 #if !defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
327 #ifndef HASH_BLOCK_DATA_ORDER
328 #error "HASH_BLOCK_DATA_ORDER must be defined!"
329 #endif
330 #endif
331
332 #if defined(DATA_ORDER_IS_BIG_ENDIAN)
333
334 #define HOST_c2l(c,l)   (l =(((unsigned long)(*((c)++)))<<24),          \
335                          l|=(((unsigned long)(*((c)++)))<<16),          \
336                          l|=(((unsigned long)(*((c)++)))<< 8),          \
337                          l|=(((unsigned long)(*((c)++)))    ),          \
338                          l)
339 #define HOST_p_c2l(c,l,n)       {                                       \
340                         switch (n) {                                    \
341                         case 0: l =((unsigned long)(*((c)++)))<<24;     \
342                         case 1: l|=((unsigned long)(*((c)++)))<<16;     \
343                         case 2: l|=((unsigned long)(*((c)++)))<< 8;     \
344                         case 3: l|=((unsigned long)(*((c)++)));         \
345                                 } }
346 #define HOST_p_c2l_p(c,l,sc,len) {                                      \
347                         switch (sc) {                                   \
348                         case 0: l =((unsigned long)(*((c)++)))<<24;     \
349                                 if (--len == 0) break;                  \
350                         case 1: l|=((unsigned long)(*((c)++)))<<16;     \
351                                 if (--len == 0) break;                  \
352                         case 2: l|=((unsigned long)(*((c)++)))<< 8;     \
353                                 } }
354 /* NOTE the pointer is not incremented at the end of this */
355 #define HOST_c2l_p(c,l,n)       {                                       \
356                         l=0; (c)+=n;                                    \
357                         switch (n) {                                    \
358                         case 3: l =((unsigned long)(*(--(c))))<< 8;     \
359                         case 2: l|=((unsigned long)(*(--(c))))<<16;     \
360                         case 1: l|=((unsigned long)(*(--(c))))<<24;     \
361                                 } }
362 #define HOST_l2c(l,c)   (*((c)++)=(unsigned char)(((l)>>24)&0xff),      \
363                          *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
364                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
365                          *((c)++)=(unsigned char)(((l)    )&0xff),      \
366                          l)
367
368 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
369
370 #define HOST_c2l(c,l)   (l =(((unsigned long)(*((c)++)))    ),          \
371                          l|=(((unsigned long)(*((c)++)))<< 8),          \
372                          l|=(((unsigned long)(*((c)++)))<<16),          \
373                          l|=(((unsigned long)(*((c)++)))<<24),          \
374                          l)
375 #define HOST_p_c2l(c,l,n)       {                                       \
376                         switch (n) {                                    \
377                         case 0: l =((unsigned long)(*((c)++)));         \
378                         case 1: l|=((unsigned long)(*((c)++)))<< 8;     \
379                         case 2: l|=((unsigned long)(*((c)++)))<<16;     \
380                         case 3: l|=((unsigned long)(*((c)++)))<<24;     \
381                                 } }
382 #define HOST_p_c2l_p(c,l,sc,len) {                                      \
383                         switch (sc) {                                   \
384                         case 0: l =((unsigned long)(*((c)++)));         \
385                                 if (--len == 0) break;                  \
386                         case 1: l|=((unsigned long)(*((c)++)))<< 8;     \
387                                 if (--len == 0) break;                  \
388                         case 2: l|=((unsigned long)(*((c)++)))<<16;     \
389                                 } }
390 /* NOTE the pointer is not incremented at the end of this */
391 #define HOST_c2l_p(c,l,n)       {                                       \
392                         l=0; (c)+=n;                                    \
393                         switch (n) {                                    \
394                         case 3: l =((unsigned long)(*(--(c))))<<16;     \
395                         case 2: l|=((unsigned long)(*(--(c))))<< 8;     \
396                         case 1: l|=((unsigned long)(*(--(c))));         \
397                                 } }
398 #define HOST_l2c(l,c)   (*((c)++)=(unsigned char)(((l)    )&0xff),      \
399                          *((c)++)=(unsigned char)(((l)>> 8)&0xff),      \
400                          *((c)++)=(unsigned char)(((l)>>16)&0xff),      \
401                          *((c)++)=(unsigned char)(((l)>>24)&0xff),      \
402                          l)
403
404 #endif
405
406 /*
407  * Time for some action:-)
408  */
409
410 void HASH_UPDATE (HASH_CTX *c, const unsigned char *data, unsigned long len)
411         {
412         register HASH_LONG * p;
413         register unsigned long l;
414         int sw,sc,ew,ec;
415
416         if (len==0) return;
417
418         l=(c->Nl+(len<<3))&0xffffffffL;
419         /* 95-05-24 eay Fixed a bug with the overflow handling, thanks to
420          * Wei Dai <weidai@eskimo.com> for pointing it out. */
421         if (l < c->Nl) /* overflow */
422                 c->Nh++;
423         c->Nh+=(len>>29);
424         c->Nl=l;
425
426         if (c->num != 0)
427                 {
428                 p=c->data;
429                 sw=c->num>>2;
430                 sc=c->num&0x03;
431
432                 if ((c->num+len) >= HASH_CBLOCK)
433                         {
434                         l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l;
435                         for (; sw<HASH_LBLOCK; sw++)
436                                 {
437                                 HOST_c2l(data,l); p[sw]=l;
438                                 }
439                         HASH_BLOCK_HOST_ORDER (c,p,1);
440                         len-=(HASH_CBLOCK-c->num);
441                         c->num=0;
442                         /* drop through and do the rest */
443                         }
444                 else
445                         {
446                         c->num+=len;
447                         if ((sc+len) < 4) /* ugly, add char's to a word */
448                                 {
449                                 l=p[sw]; HOST_p_c2l_p(data,l,sc,len); p[sw]=l;
450                                 }
451                         else
452                                 {
453                                 ew=(c->num>>2);
454                                 ec=(c->num&0x03);
455                                 l=p[sw]; HOST_p_c2l(data,l,sc); p[sw++]=l;
456                                 for (; sw < ew; sw++)
457                                         {
458                                         HOST_c2l(data,l); p[sw]=l;
459                                         }
460                                 if (ec)
461                                         {
462                                         HOST_c2l_p(data,l,ec); p[sw]=l;
463                                         }
464                                 }
465                         return;
466                         }
467                 }
468
469         sw=len/HASH_CBLOCK;
470         if (sw > 0)
471                 {
472 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
473                 /*
474                  * Note that HASH_BLOCK_DATA_ORDER_ALIGNED gets defined
475                  * only if sizeof(HASH_LONG)==4.
476                  */
477                 if ((((unsigned long)data)%4) == 0)
478                         {
479                         /* data is properly aligned so that we can cast it: */
480                         HASH_BLOCK_DATA_ORDER_ALIGNED (c,(HASH_LONG *)data,sw);
481                         sw*=HASH_CBLOCK;
482                         data+=sw;
483                         len-=sw;
484                         }
485                 else
486 #if !defined(HASH_BLOCK_DATA_ORDER)
487                         while (sw--)
488                                 {
489                                 memcpy (p=c->data,data,HASH_CBLOCK);
490                                 HASH_BLOCK_DATA_ORDER_ALIGNED(c,p,1);
491                                 data+=HASH_CBLOCK;
492                                 len-=HASH_CBLOCK;
493                                 }
494 #endif
495 #endif
496 #if defined(HASH_BLOCK_DATA_ORDER)
497                         {
498                         HASH_BLOCK_DATA_ORDER(c,data,sw);
499                         sw*=HASH_CBLOCK;
500                         data+=sw;
501                         len-=sw;
502                         }
503 #endif
504                 }
505
506         if (len!=0)
507                 {
508                 p = c->data;
509                 c->num = len;
510                 ew=len>>2;      /* words to copy */
511                 ec=len&0x03;
512                 for (; ew; ew--,p++)
513                         {
514                         HOST_c2l(data,l); *p=l;
515                         }
516                 HOST_c2l_p(data,l,ec);
517                 *p=l;
518                 }
519         }
520
521
522 void HASH_TRANSFORM (HASH_CTX *c, const unsigned char *data)
523         {
524 #if defined(HASH_BLOCK_DATA_ORDER_ALIGNED)
525         if ((((unsigned long)data)%4) == 0)
526                 /* data is properly aligned so that we can cast it: */
527                 HASH_BLOCK_DATA_ORDER_ALIGNED (c,(HASH_LONG *)data,1);
528         else
529 #if !defined(HASH_BLOCK_DATA_ORDER)
530                 {
531                 memcpy (c->data,data,HASH_CBLOCK);
532                 HASH_BLOCK_DATA_ORDER_ALIGNED (c,c->data,1);
533                 }
534 #endif
535 #endif
536 #if defined(HASH_BLOCK_DATA_ORDER)
537         HASH_BLOCK_DATA_ORDER (c,data,1);
538 #endif
539         }
540
541
542 void HASH_FINAL (unsigned char *md, HASH_CTX *c)
543         {
544         register HASH_LONG *p;
545         register unsigned long l;
546         register int i,j;
547         static const unsigned char end[4]={0x80,0x00,0x00,0x00};
548         const unsigned char *cp=end;
549
550         /* c->num should definitly have room for at least one more byte. */
551         p=c->data;
552         i=c->num>>2;
553         j=c->num&0x03;
554
555 #if 0
556         /* purify often complains about the following line as an
557          * Uninitialized Memory Read.  While this can be true, the
558          * following p_c2l macro will reset l when that case is true.
559          * This is because j&0x03 contains the number of 'valid' bytes
560          * already in p[i].  If and only if j&0x03 == 0, the UMR will
561          * occur but this is also the only time p_c2l will do
562          * l= *(cp++) instead of l|= *(cp++)
563          * Many thanks to Alex Tang <altitude@cic.net> for pickup this
564          * 'potential bug' */
565 #ifdef PURIFY
566         if (j==0) p[i]=0; /* Yeah, but that's not the way to fix it:-) */
567 #endif
568         l=p[i];
569 #else
570         l = (j==0) ? 0 : p[i];
571 #endif
572         HOST_p_c2l(cp,l,j); p[i++]=l; /* i is the next 'undefined word' */
573
574         if (i>(HASH_LBLOCK-2)) /* save room for Nl and Nh */
575                 {
576                 if (i<HASH_LBLOCK) p[i]=0;
577                 HASH_BLOCK_HOST_ORDER (c,p,1);
578                 i=0;
579                 }
580         for (; i<(HASH_LBLOCK-2); i++)
581                 p[i]=0;
582
583 #if   defined(DATA_ORDER_IS_BIG_ENDIAN)
584         p[HASH_LBLOCK-2]=c->Nh;
585         p[HASH_LBLOCK-1]=c->Nl;
586 #elif defined(DATA_ORDER_IS_LITTLE_ENDIAN)
587         p[HASH_LBLOCK-2]=c->Nl;
588         p[HASH_LBLOCK-1]=c->Nh;
589 #endif
590         HASH_BLOCK_HOST_ORDER (c,p,1);
591
592 #ifndef HASH_MAKE_STRING
593 #error "HASH_MAKE_STRING must be defined!"
594 #else
595         HASH_MAKE_STRING(c,md);
596 #endif
597
598         c->num=0;
599         /* clear stuff, HASH_BLOCK may be leaving some stuff on the stack
600          * but I'm not worried :-)
601         memset((void *)c,0,sizeof(HASH_CTX));
602          */
603         }