/*
??$Id:?cbc_d_m.cv?1.11?1998/06/10?20:04:10?fms?Exp?$

??#?This?file?is?part?of?the?C?reference?implementation?of?Serpent.
??#
??#?Written?by?Frank?Stajano
??#?Olivetti?Oracle?Research?Laboratory??and
??#?Cambridge?University?Computer?Laboratory?.
??#?
??#?（c）?1998?Olivetti?Oracle?Research?Laboratory?（ORL）
??#
??#?Original?（Python）?Serpent?reference?development?started?on?1998?02?12.
??#?C?implementation?development?started?on?1998?03?04.
??#
??#?Serpent?cipher?invented?by?Ross?Anderson?Eli?Biham?Lars?Knudsen.
??#?Serpent?is?a?candidate?for?the?Advanced?Encryption?Standard.
??
*/

/*?--------------------------------------------------?*/
#include?
#include?“serpent-api.h“
#include?“serpent-aux.h“
/*?--------------------------------------------------?*/
embed_RCS（cbc_d_m_c
??????????“$Id:?cbc_d_m.cv?1.11?1998/06/10?20:04:10?fms?Exp?$“）


/*?The?“NIST?SPEC“?markers?refer?to?the?pseudo-code?instructions?in?figure
???6?（Monte?Carlo?Test?-?CBC?Decryption）?of?the?NIST?document?“Description
???of?Known?Answer?Tests?and?Monte?Carlo?Tests?for?Advanced?Encryption
???Standard?（AES）?Candidate?Algorithm?Submissions“?as?updated?on?February
???17?1998?*/

int?main（void）?{
??int?i?j?k?bitsPerShortKey?result;
??BLOCK?plainText?cipherText?PT_9998;
??KEY?binaryKey;
??char?asciiKey[HEX_DIGITS_PER_KEY+1];
??keyInstance?key;
??cipherInstance?cipher;


??/*?The?hack?that?remembers?PT_9998?only?works?if...?*/
??assert（BITS_PER_KEY?<=?2*BITS_PER_BLOCK）;
??/*?...otherwise?we‘d?have?to?remember?more?than?just?PT_9998.?*/

??printHeader（“cbc_d_m“?“Cipher?Block?Chaining?（CBC）?Mode?-?DECRYPTION“
??????????????“Monte?Carlo?Test“）;

??for（bitsPerShortKey=BITS_PER_SHORTEST_KEY;?bitsPerShortKey<=BITS_PER_KEY;
??????bitsPerShortKey+=BITS_PER_KEY_STEP）?{
????printf（“KEYSIZE=%d\n\n“?bitsPerShortKey）;

????/*?Construct?（backwards）?an?ascii?key?of?all?0s?of?length
???????bitsPerShortKey?bits.?*/
????i=bitsPerShortKey/BITS_PER_HEX_DIGIT;
????asciiKey[i]?=?0;?/*?terminating?null?*/?
????for?（i--;?i?>=0;?i--）?{
??????asciiKey[i]?=?‘0‘;
????}
????result?=?makeKey（&key?DIR_DECRYPT?bitsPerShortKey?asciiKey）;
????if?（result?!=?TRUE）?goto?error;

????result?=?stringToWords（“00000000000000000000000000000000“?cipherText
???????????????????????????WORDS_PER_BLOCK）;
????if?（result?!=?TRUE）?goto?error;
????result?=?cipherInit（&cipher?MODE_CBC?“00000000000000000000000000000000“）;
????if?（result?!=?TRUE）?goto?error;

????for（i=0;?i??????/*?NIST?SPEC:?if?（i==0）?CV_0?=?IV_0?*/
??????/*?This?has?already?been?done?by?cipherInit?outside?this?loop.?Our?CV
?????????is?held?in?cipher.IV.?*/

??????/*?NIST?SPEC:?Record?i?KEY_i?CV_0?CT_0?*/
??????printf（“I=%d\n“?i）;
??????render（“KEY=“?key.userKey?bitsPerShortKey/BITS_PER_WORD）;
??????render（“IV=“?（WORD*）?cipher.IV?WORDS_PER_BLOCK）;
??????render（“CT=“?cip