* [including the GNU Public Licence.]
*/
-#include "rc4.h"
+#include <openssl/rc4.h>
#include "rc4_locl.h"
/* RC4 as implemented from a posting from
* Date: Wed, 14 Sep 1994 06:35:31 GMT
*/
-void RC4(key, len, indata, outdata)
-RC4_KEY *key;
-unsigned long len;
-unsigned char *indata;
-unsigned char *outdata;
+void RC4(RC4_KEY *key, size_t len, const unsigned char *indata,
+ unsigned char *outdata)
{
register RC4_INT *d;
register RC4_INT x,y,tx,ty;
- int i;
+ size_t i;
x=key->x;
y=key->y;
d=key->data;
+#if defined(RC4_CHUNK)
+ /*
+ * The original reason for implementing this(*) was the fact that
+ * pre-21164a Alpha CPUs don't have byte load/store instructions
+ * and e.g. a byte store has to be done with 64-bit load, shift,
+ * and, or and finally 64-bit store. Peaking data and operating
+ * at natural word size made it possible to reduce amount of
+ * instructions as well as to perform early read-ahead without
+ * suffering from RAW (read-after-write) hazard. This resulted
+ * in ~40%(**) performance improvement on 21064 box with gcc.
+ * But it's not only Alpha users who win here:-) Thanks to the
+ * early-n-wide read-ahead this implementation also exhibits
+ * >40% speed-up on SPARC and 20-30% on 64-bit MIPS (depending
+ * on sizeof(RC4_INT)).
+ *
+ * (*) "this" means code which recognizes the case when input
+ * and output pointers appear to be aligned at natural CPU
+ * word boundary
+ * (**) i.e. according to 'apps/openssl speed rc4' benchmark,
+ * crypto/rc4/rc4speed.c exhibits almost 70% speed-up...
+ *
+ * Cavets.
+ *
+ * - RC4_CHUNK="unsigned long long" should be a #1 choice for
+ * UltraSPARC. Unfortunately gcc generates very slow code
+ * (2.5-3 times slower than one generated by Sun's WorkShop
+ * C) and therefore gcc (at least 2.95 and earlier) should
+ * always be told that RC4_CHUNK="unsigned long".
+ *
+ * <appro@fy.chalmers.se>
+ */
+
+# define RC4_STEP ( \
+ x=(x+1) &0xff, \
+ tx=d[x], \
+ y=(tx+y)&0xff, \
+ ty=d[y], \
+ d[y]=tx, \
+ d[x]=ty, \
+ (RC4_CHUNK)d[(tx+ty)&0xff]\
+ )
+
+ if ( ( ((size_t)indata & (sizeof(RC4_CHUNK)-1)) |
+ ((size_t)outdata & (sizeof(RC4_CHUNK)-1)) ) == 0 )
+ {
+ RC4_CHUNK ichunk,otp;
+ const union { long one; char little; } is_endian = {1};
+
+ /*
+ * I reckon we can afford to implement both endian
+ * cases and to decide which way to take at run-time
+ * because the machine code appears to be very compact
+ * and redundant 1-2KB is perfectly tolerable (i.e.
+ * in case the compiler fails to eliminate it:-). By
+ * suggestion from Terrel Larson <terr@terralogic.net>
+ * who also stands for the is_endian union:-)
+ *
+ * Special notes.
+ *
+ * - is_endian is declared automatic as doing otherwise
+ * (declaring static) prevents gcc from eliminating
+ * the redundant code;
+ * - compilers (those I've tried) don't seem to have
+ * problems eliminating either the operators guarded
+ * by "if (sizeof(RC4_CHUNK)==8)" or the condition
+ * expressions themselves so I've got 'em to replace
+ * corresponding #ifdefs from the previous version;
+ * - I chose to let the redundant switch cases when
+ * sizeof(RC4_CHUNK)!=8 be (were also #ifdefed
+ * before);
+ * - in case you wonder "&(sizeof(RC4_CHUNK)*8-1)" in
+ * [LB]ESHFT guards against "shift is out of range"
+ * warnings when sizeof(RC4_CHUNK)!=8
+ *
+ * <appro@fy.chalmers.se>
+ */
+ if (!is_endian.little)
+ { /* BIG-ENDIAN CASE */
+# define BESHFT(c) (((sizeof(RC4_CHUNK)-(c)-1)*8)&(sizeof(RC4_CHUNK)*8-1))
+ for (;len&(0-sizeof(RC4_CHUNK));len-=sizeof(RC4_CHUNK))
+ {
+ ichunk = *(RC4_CHUNK *)indata;
+ otp = RC4_STEP<<BESHFT(0);
+ otp |= RC4_STEP<<BESHFT(1);
+ otp |= RC4_STEP<<BESHFT(2);
+ otp |= RC4_STEP<<BESHFT(3);
+ if (sizeof(RC4_CHUNK)==8)
+ {
+ otp |= RC4_STEP<<BESHFT(4);
+ otp |= RC4_STEP<<BESHFT(5);
+ otp |= RC4_STEP<<BESHFT(6);
+ otp |= RC4_STEP<<BESHFT(7);
+ }
+ *(RC4_CHUNK *)outdata = otp^ichunk;
+ indata += sizeof(RC4_CHUNK);
+ outdata += sizeof(RC4_CHUNK);
+ }
+ if (len)
+ {
+ RC4_CHUNK mask=(RC4_CHUNK)-1, ochunk;
+
+ ichunk = *(RC4_CHUNK *)indata;
+ ochunk = *(RC4_CHUNK *)outdata;
+ otp = 0;
+ i = BESHFT(0);
+ mask <<= (sizeof(RC4_CHUNK)-len)<<3;
+ switch (len&(sizeof(RC4_CHUNK)-1))
+ {
+ case 7: otp = RC4_STEP<<i, i-=8;
+ case 6: otp |= RC4_STEP<<i, i-=8;
+ case 5: otp |= RC4_STEP<<i, i-=8;
+ case 4: otp |= RC4_STEP<<i, i-=8;
+ case 3: otp |= RC4_STEP<<i, i-=8;
+ case 2: otp |= RC4_STEP<<i, i-=8;
+ case 1: otp |= RC4_STEP<<i, i-=8;
+ case 0: ; /*
+ * it's never the case,
+ * but it has to be here
+ * for ultrix?
+ */
+ }
+ ochunk &= ~mask;
+ ochunk |= (otp^ichunk) & mask;
+ *(RC4_CHUNK *)outdata = ochunk;
+ }
+ key->x=x;
+ key->y=y;
+ return;
+ }
+ else
+ { /* LITTLE-ENDIAN CASE */
+# define LESHFT(c) (((c)*8)&(sizeof(RC4_CHUNK)*8-1))
+ for (;len&(0-sizeof(RC4_CHUNK));len-=sizeof(RC4_CHUNK))
+ {
+ ichunk = *(RC4_CHUNK *)indata;
+ otp = RC4_STEP;
+ otp |= RC4_STEP<<8;
+ otp |= RC4_STEP<<16;
+ otp |= RC4_STEP<<24;
+ if (sizeof(RC4_CHUNK)==8)
+ {
+ otp |= RC4_STEP<<LESHFT(4);
+ otp |= RC4_STEP<<LESHFT(5);
+ otp |= RC4_STEP<<LESHFT(6);
+ otp |= RC4_STEP<<LESHFT(7);
+ }
+ *(RC4_CHUNK *)outdata = otp^ichunk;
+ indata += sizeof(RC4_CHUNK);
+ outdata += sizeof(RC4_CHUNK);
+ }
+ if (len)
+ {
+ RC4_CHUNK mask=(RC4_CHUNK)-1, ochunk;
+
+ ichunk = *(RC4_CHUNK *)indata;
+ ochunk = *(RC4_CHUNK *)outdata;
+ otp = 0;
+ i = 0;
+ mask >>= (sizeof(RC4_CHUNK)-len)<<3;
+ switch (len&(sizeof(RC4_CHUNK)-1))
+ {
+ case 7: otp = RC4_STEP, i+=8;
+ case 6: otp |= RC4_STEP<<i, i+=8;
+ case 5: otp |= RC4_STEP<<i, i+=8;
+ case 4: otp |= RC4_STEP<<i, i+=8;
+ case 3: otp |= RC4_STEP<<i, i+=8;
+ case 2: otp |= RC4_STEP<<i, i+=8;
+ case 1: otp |= RC4_STEP<<i, i+=8;
+ case 0: ; /*
+ * it's never the case,
+ * but it has to be here
+ * for ultrix?
+ */
+ }
+ ochunk &= ~mask;
+ ochunk |= (otp^ichunk) & mask;
+ *(RC4_CHUNK *)outdata = ochunk;
+ }
+ key->x=x;
+ key->y=y;
+ return;
+ }
+ }
+#endif
#define LOOP(in,out) \
x=((x+1)&0xff); \
tx=d[x]; \
#define RC4_LOOP(a,b,i) LOOP(a[i],b[i])
#endif
- i=(int)(len>>3L);
+ i=len>>3;
if (i)
{
for (;;)
if (--i == 0) break;
}
}
- i=(int)len&0x07;
+ i=len&0x07;
if (i)
{
for (;;)
projects / openssl.git / blobdiff