crypto/idea/idea_lcl.h

   1 /*
   2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*
  11  * The new form of this macro (check if the a*b == 0) was suggested by Colin
  12  * Plumb <colin@nyx10.cs.du.edu>
  13  */
  14 /* Removal of the inner if from from Wei Dai 24/4/96 */
  15 #define idea_mul(r,a,b,ul) \
  16 ul=(unsigned long)a*b; \
  17 if (ul != 0) \
  18         { \
  19         r=(ul&0xffff)-(ul>>16); \
  20         r-=((r)>>16); \
  21         } \
  22 else \
  23         r=(-(int)a-b+1);        /* assuming a or b is 0 and in range */
  24
  25 /*
  26  * 7/12/95 - Many thanks to Rhys Weatherley <rweather@us.oracle.com> for
  27  * pointing out that I was assuming little endian byte order for all
  28  * quantities what idea actually used bigendian.  No where in the spec does
  29  * it mention this, it is all in terms of 16 bit numbers and even the example
  30  * does not use byte streams for the input example :-(. If you byte swap each
  31  * pair of input, keys and iv, the functions would produce the output as the
  32  * old version :-(.
  33  */
  34
  35 /* NOTE - c is not incremented as per n2l */
  36 #define n2ln(c,l1,l2,n) { \
  37                         c+=n; \
  38                         l1=l2=0; \
  39                         switch (n) { \
  40                         case 8: l2 =((unsigned long)(*(--(c))))    ; \
  41                         case 7: l2|=((unsigned long)(*(--(c))))<< 8; \
  42                         case 6: l2|=((unsigned long)(*(--(c))))<<16; \
  43                         case 5: l2|=((unsigned long)(*(--(c))))<<24; \
  44                         case 4: l1 =((unsigned long)(*(--(c))))    ; \
  45                         case 3: l1|=((unsigned long)(*(--(c))))<< 8; \
  46                         case 2: l1|=((unsigned long)(*(--(c))))<<16; \
  47                         case 1: l1|=((unsigned long)(*(--(c))))<<24; \
  48                                 } \
  49                         }
  50
  51 /* NOTE - c is not incremented as per l2n */
  52 #define l2nn(l1,l2,c,n) { \
  53                         c+=n; \
  54                         switch (n) { \
  55                         case 8: *(--(c))=(unsigned char)(((l2)    )&0xff); \
  56                         case 7: *(--(c))=(unsigned char)(((l2)>> 8)&0xff); \
  57                         case 6: *(--(c))=(unsigned char)(((l2)>>16)&0xff); \
  58                         case 5: *(--(c))=(unsigned char)(((l2)>>24)&0xff); \
  59                         case 4: *(--(c))=(unsigned char)(((l1)    )&0xff); \
  60                         case 3: *(--(c))=(unsigned char)(((l1)>> 8)&0xff); \
  61                         case 2: *(--(c))=(unsigned char)(((l1)>>16)&0xff); \
  62                         case 1: *(--(c))=(unsigned char)(((l1)>>24)&0xff); \
  63                                 } \
  64                         }
  65
  66 #undef n2l
  67 #define n2l(c,l)        (l =((unsigned long)(*((c)++)))<<24L, \
  68                          l|=((unsigned long)(*((c)++)))<<16L, \
  69                          l|=((unsigned long)(*((c)++)))<< 8L, \
  70                          l|=((unsigned long)(*((c)++))))
  71
  72 #undef l2n
  73 #define l2n(l,c)        (*((c)++)=(unsigned char)(((l)>>24L)&0xff), \
  74                          *((c)++)=(unsigned char)(((l)>>16L)&0xff), \
  75                          *((c)++)=(unsigned char)(((l)>> 8L)&0xff), \
  76                          *((c)++)=(unsigned char)(((l)     )&0xff))
  77
  78 #undef s2n
  79 #define s2n(l,c)        (*((c)++)=(unsigned char)(((l)     )&0xff), \
  80                          *((c)++)=(unsigned char)(((l)>> 8L)&0xff))
  81
  82 #undef n2s
  83 #define n2s(c,l)        (l =((IDEA_INT)(*((c)++)))<< 8L, \
  84                          l|=((IDEA_INT)(*((c)++)))      )
  85
  86
  87 #define E_IDEA(num) \
  88         x1&=0xffff; \
  89         idea_mul(x1,x1,*p,ul); p++; \
  90         x2+= *(p++); \
  91         x3+= *(p++); \
  92         x4&=0xffff; \
  93         idea_mul(x4,x4,*p,ul); p++; \
  94         t0=(x1^x3)&0xffff; \
  95         idea_mul(t0,t0,*p,ul); p++; \
  96         t1=(t0+(x2^x4))&0xffff; \
  97         idea_mul(t1,t1,*p,ul); p++; \
  98         t0+=t1; \
  99         x1^=t1; \
 100         x4^=t0; \
 101         ul=x2^t0; /* do the swap to x3 */ \
 102         x2=x3^t1; \
 103         x3=ul;