/*?RC5REF.C?--?Reference?implementation?of?RC5-32/12/16?in?C.????????*/
/*?Copyright?（C）?1995?RSA?Data?Security?Inc.????????????????????????*/
#include?
#include?
typedef?unsigned?long?int?WORD;?/*?Should?be?32-bit?=?4?bytes????????*/
#define?w????????32?????????????/*?word?size?in?bits?????????????????*/
#define?r????????12?????????????/*?number?of?rounds??????????????????*/??
#define?b????????16?????????????/*?number?of?bytes?in?key????????????*/
#define?c?????????4?????????????/*?number??words?in?key?=?ceil（8*b/w）*/
#define?t????????26?????????????/*?size?of?table?S?=?2*（r+1）?words???*/
WORD?S[t];??????????????????????/*?expanded?key?table????????????????*/
WORD?P?=?0xb7e15163?Q?=?0x9e3779b9;??/*?magic?constants?????????????*/
/*?Rotation?operators.?x?must?be?unsigned?to?get?logical?right?shift*/
#define?ROTL（xy）?（（（x）<<（y&（w-1）））?|?（（x）>>（w-（y&（w-1）））））
#define?ROTR（xy）?（（（x）>>（y&（w-1）））?|?（（x）<<（w-（y&（w-1）））））

void?RC5_ENCRYPT（WORD?*pt?WORD?*ct）?/*?2?WORD?input?pt/output?ct????*/
{?WORD?i?A=pt[0]+S[0]?B=pt[1]+S[1];
??for?（i=1;?i<=r;?i++）?
????{?A?=?ROTL（A^BB）+S[2*i];?
??????B?=?ROTL（B^AA）+S[2*i+1];?
????}
??ct[0]?=?A;?ct[1]?=?B;??
}?

void?RC5_DECRYPT（WORD?*ct?WORD?*pt）?/*?2?WORD?input?ct/output?pt????*/
{?WORD?i?B=ct[1]?A=ct[0];
??for?（i=r;?i>0;?i--）?
????{?B?=?ROTR（B-S[2*i+1]A）^A;?
??????A?=?ROTR（A-S[2*i]B）^B;?
????}
??pt[1]?=?B-S[1];?pt[0]?=?A-S[0];??
}?

void?RC5_SETUP（unsigned?char?*K）?/*?secret?input?key?K[0...b-1]??????*/
{??WORD?i?j?k?u=w/8?A?B?L[c];?
???/*?Initialize?L?then?S?then?mix?key?into?S?*/
???for?（i=b-1L[c-1]=0;?i!=-1;?i--）?L[i/u]?=?（L[i/u]<<8）+K[i];
???for?（S[0]=Pi=1;?i???for?（A=B=i=j=k=0;?k<3*t;?k++i=（i+1）%tj=（j+1）%c）???/*?3*t?>?3*c?*/
?????{?A?=?S[i]?=?ROTL（S[i]+（A+B）3）;??
???????B?=?L[j]?=?ROTL（L[j]+（A+B）（A+B））;?
?????}?
}?

void?main（）
{?WORD?i?j?pt1[2]?pt2[2]?ct[2]?=?{00};
??unsigned?char?key[b];
??time_t?t0?t1;
??if?（sizeof（WORD）!=4）?
????printf（“RC5?error:?WORD?has?%d?bytes.\n“sizeof（WORD））;
??printf（“RC5-32/12/16?examples:\n“）;
??for?（i=1;i<6;i++）
????{?/*?Initialize?pt1?and?key?pseudorandomly?based?on?previous?ct?*/
??????pt1[0]=ct[0];?pt1[1]=ct[1];?
??????for?（j=0;j??????/*?Setup?encrypt?and?decrypt?*/
??????RC5_SETUP（key）;??
??????RC5_ENCRYPT（pt1ct）;??
??????RC5_DECRYPT（ctpt2）;
??????/*?Print?out?results?checking?for?decryption?failure?*/
??????printf（“\n%d.?key?=?“i）;?
??????for?（j=0;?j??????printf（“\n???plaintext?%.8lX?%.8lX??--->??ciphertext?%.8lX?%.8lX??\n“
?????????????pt1[0]?pt1[1]?ct[0]?ct[1]）;
??????if?（pt1[0]!=pt2[0]?||?pt1[1]!=pt2[1]）?
????????printf（“Decryption?Error!“）;
????}
??time?（&t0）;
??for?（i=1;i<100000;i++）
????RC5_ENCRYPT（ctct）;
??time?（&t1）;
??printf?（“\n???Time_t?for?100000?blocks:??%ld?\n“?t1-t0）;
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????5963??1999-09-02?12:49??rc5-info-from-rsa.txt
?????文件???????31896??1999-09-02?12:50??rc5.ps.gz
?????文件????????7089??1999-09-02?12:50??rc5.tex.gz
?????文件????????2862??1999-09-02?12:50??rc5ref.c
?????文件?????????697??1999-09-02?12:50??rc5ref.out