diff options
Diffstat (limited to 'crypto/openssl/crypto/rc4/rc4_enc.c')
| -rw-r--r-- | crypto/openssl/crypto/rc4/rc4_enc.c | 186 |
1 files changed, 185 insertions, 1 deletions
diff --git a/crypto/openssl/crypto/rc4/rc4_enc.c b/crypto/openssl/crypto/rc4/rc4_enc.c index 3256bea..d5f18a3 100644 --- a/crypto/openssl/crypto/rc4/rc4_enc.c +++ b/crypto/openssl/crypto/rc4/rc4_enc.c @@ -67,7 +67,7 @@ * Date: Wed, 14 Sep 1994 06:35:31 GMT */ -void RC4(RC4_KEY *key, unsigned long len, unsigned char *indata, +void RC4(RC4_KEY *key, unsigned long len, const unsigned char *indata, unsigned char *outdata) { register RC4_INT *d; @@ -78,6 +78,190 @@ void RC4(RC4_KEY *key, unsigned long len, unsigned char *indata, 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 ( ( ((unsigned long)indata & (sizeof(RC4_CHUNK)-1)) | + ((unsigned long)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&-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&-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]; \ |
