Source Listing                   9-SEP-1997 11:09:50    DEC C V5.0-003                      Page   1
                                                                30-SEP-1996 09:27:36    X$SRC:[CSO.PH]CRYPT.C;1

	      1 /*#if defined(LIBC_SCCS) && !defined(lint)*/
	      2 #ifdef LIBC_SCCS
       X      3 #ifndef lint
       X      4 static char sccsid[] = "@(#)crypt.c	5.2 (Berkeley) 3/9/86";
       X      5 #endif
       X      6 #endif LIBC_SCCS and not lint
	      7 
	      8 /*
	      9  * This program implements the
	     10  * Proposed Federal Information Processing
	     11  *  Data Encryption Standard.
	     12  * See Federal Register, March 17, 1975 (40FR12134)
	     13  */
	     14 
	     15 /*
	     16  * Initial permutation,
	     17  */
	     18 static	char	IP[] = {
	     19 	58,50,42,34,26,18,10, 2,
	     20 	60,52,44,36,28,20,12, 4,
	     21 	62,54,46,38,30,22,14, 6,
	     22 	64,56,48,40,32,24,16, 8,
	     23 	57,49,41,33,25,17, 9, 1,
	     24 	59,51,43,35,27,19,11, 3,
	     25 	61,53,45,37,29,21,13, 5,
	     26 	63,55,47,39,31,23,15, 7,
	     27 };
	     28 
	     29 /*
	     30  * Final permutation, FP = IP^(-1)
	     31  */
	     32 static	char	FP[] = {
	     33 	40, 8,48,16,56,24,64,32,
	     34 	39, 7,47,15,55,23,63,31,
	     35 	38, 6,46,14,54,22,62,30,
	     36 	37, 5,45,13,53,21,61,29,
	     37 	36, 4,44,12,52,20,60,28,
	     38 	35, 3,43,11,51,19,59,27,
	     39 	34, 2,42,10,50,18,58,26,
	     40 	33, 1,41, 9,49,17,57,25,
	     41 };
	     42 
	     43 /*
	     44  * Permuted-choice 1 from the key bits
	     45  * to yield C and D.
	     46  * Note that bits 8,16... are left out:
	     47  * They are intended for a parity check.
	     48  */
	     49 static	char	PC1_C[] = {
	     50 	57,49,41,33,25,17, 9,
	     51 	 1,58,50,42,34,26,18,
	     52 	10, 2,59,51,43,35,27,
	     53 	19,11, 3,60,52,44,36,
	     54 };
	     55 
	     56 static	char	PC1_D[] = {
	     57 	63,55,47,39,31,23,15,

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                                                                30-SEP-1996 09:27:36    X$SRC:[CSO.PH]CRYPT.C;1

	     58 	 7,62,54,46,38,30,22,
	     59 	14, 6,61,53,45,37,29,
	     60 	21,13, 5,28,20,12, 4,
	     61 };
	     62 
	     63 /*
	     64  * Sequence of shifts used for the key schedule.
	     65 */
	     66 static	char	shifts[] = {
	     67 	1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,
	     68 };
	     69 
	     70 /*
	     71  * Permuted-choice 2, to pick out the bits from
	     72  * the CD array that generate the key schedule.
	     73  */
	     74 static	char	PC2_C[] = {
	     75 	14,17,11,24, 1, 5,
	     76 	 3,28,15, 6,21,10,
	     77 	23,19,12, 4,26, 8,
	     78 	16, 7,27,20,13, 2,
	     79 };
	     80 
	     81 static	char	PC2_D[] = {
	     82 	41,52,31,37,47,55,
	     83 	30,40,51,45,33,48,
	     84 	44,49,39,56,34,53,
	     85 	46,42,50,36,29,32,
	     86 };
	     87 
	     88 /*
	     89  * The C and D arrays used to calculate the key schedule.
	     90  */
	     91 
	     92 static	char	C[28];
	     93 static	char	D[28];
	     94 /*
	     95  * The key schedule.
	     96  * Generated from the key.
	     97  */
	     98 static	char	KS[16][48];
	     99 
	    100 /*
	    101  * The E bit-selection table.
	    102  */
	    103 static	char	E[48];
	    104 static	char	e[] = {
	    105 	32, 1, 2, 3, 4, 5,
	    106 	 4, 5, 6, 7, 8, 9,
	    107 	 8, 9,10,11,12,13,
	    108 	12,13,14,15,16,17,
	    109 	16,17,18,19,20,21,
	    110 	20,21,22,23,24,25,
	    111 	24,25,26,27,28,29,
	    112 	28,29,30,31,32, 1,
	    113 };
	    114 

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                                                                30-SEP-1996 09:27:36    X$SRC:[CSO.PH]CRYPT.C;1

	    115 /*
	    116  * Set up the key schedule from the key.
	    117  */
	    118 
	    119 setkey(key)
	    120 char *key;
	    121 {
	    122 	register i, j, k;
	    123 	int t;
	    124 
	    125 	/*
	    126 	 * First, generate C and D by permuting
	    127 	 * the key.  The low order bit of each
	    128 	 * 8-bit char is not used, so C and D are only 28
	    129 	 * bits apiece.
	    130 	 */
	    131 	for (i=0; i<28; i++) {
	    132 		C[i] = key[PC1_C[i]-1];
	    133 		D[i] = key[PC1_D[i]-1];
	    134 	}
	    135 	/*
	    136 	 * To generate Ki, rotate C and D according
	    137 	 * to schedule and pick up a permutation
	    138 	 * using PC2.
	    139 	 */
	    140 	for (i=0; i<16; i++) {
	    141 		/*
	    142 		 * rotate.
	    143 		 */
	    144 		for (k=0; k<shifts[i]; k++) {
	    145 			t = C[0];
	    146 			for (j=0; j<28-1; j++)
	    147 				C[j] = C[j+1];
	    148 			C[27] = t;
	    149 			t = D[0];
	    150 			for (j=0; j<28-1; j++)
	    151 				D[j] = D[j+1];
	    152 			D[27] = t;
	    153 		}
	    154 		/*
	    155 		 * get Ki. Note C and D are concatenated.
	    156 		 */
	    157 		for (j=0; j<24; j++) {
	    158 			KS[i][j] = C[PC2_C[j]-1];
	    159 			KS[i][j+24] = D[PC2_D[j]-28-1];
	    160 		}
	    161 	}
	    162 
	    163 	for(i=0;i<48;i++)
	    164 		E[i] = e[i];
	    165 }
	    166 
	    167 /*
	    168  * The 8 selection functions.
	    169  * For some reason, they give a 0-origin
	    170  * index, unlike everything else.
	    171  */

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	    172 static	char	S[8][64] = {
	    173 	14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
	    174 	 0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
	    175 	 4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
	    176 	15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13,
	    177 
	    178 	15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
	    179 	 3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
	    180 	 0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
	    181 	13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9,
	    182 
	    183 	10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
	    184 	13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
	    185 	13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
	    186 	 1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12,
	    187 
	    188 	 7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
	    189 	13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
	    190 	10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
	    191 	 3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14,
	    192 
	    193 	 2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
	    194 	14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
	    195 	 4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
	    196 	11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3,
	    197 
	    198 	12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
	    199 	10,15, 4, 2, 7,12, 9, 5, 6, 1,13,14, 0,11, 3, 8,
	    200 	 9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
	    201 	 4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13,
	    202 
	    203 	 4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
	    204 	13, 0,11, 7, 4, 9, 1,10,14, 3, 5,12, 2,15, 8, 6,
	    205 	 1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
	    206 	 6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12,
	    207 
	    208 	13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
	    209 	 1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
	    210 	 7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
	    211 	 2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11,
	    212 };
	    213 
	    214 /*
	    215  * P is a permutation on the selected combination
	    216  * of the current L and key.
	    217  */
	    218 static	char	P[] = {
	    219 	16, 7,20,21,
	    220 	29,12,28,17,
	    221 	 1,15,23,26,
	    222 	 5,18,31,10,
	    223 	 2, 8,24,14,
	    224 	32,27, 3, 9,
	    225 	19,13,30, 6,
	    226 	22,11, 4,25,
	    227 };
	    228 

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	    229 /*
	    230  * The current block, divided into 2 halves.
	    231  */
	    232 static	char	L[32], R[32];
	    233 static	char	tempL[32];
	    234 static	char	f[32];
	    235 
	    236 /*
	    237  * The combination of the key and the input, before selection.
	    238  */
	    239 static	char	preS[48];
	    240 
	    241 /*
	    242  * The payoff: encrypt a block.
	    243  */
	    244 
	    245 encrypt(block, edflag)
	    246 char *block;
	    247 {
	    248 	int i, ii;
	    249 	register t, j, k;
	    250 
	    251 	/*
	    252 	 * First, permute the bits in the input
	    253 	 */
	    254 	for (j=0; j<64; j++)
	    255 		L[j] = block[IP[j]-1];
	    256 	/*
	    257 	 * Perform an encryption operation 16 times.
	    258 	 */
	    259 	for (ii=0; ii<16; ii++) {
	    260 		/*
	    261 		 * Set direction
	    262 		 */
	    263 		if (edflag)
	    264 			i = 15-ii;
	    265 		else
	    266 			i = ii;
	    267 		/*
	    268 		 * Save the R array,
	    269 		 * which will be the new L.
	    270 		 */
	    271 		for (j=0; j<32; j++)
	    272 			tempL[j] = R[j];
	    273 		/*
	    274 		 * Expand R to 48 bits using the E selector;
	    275 		 * exclusive-or with the current key bits.
	    276 		 */
	    277 		for (j=0; j<48; j++)
	    278 			preS[j] = R[E[j]-1] ^ KS[i][j];
	    279 		/*
	    280 		 * The pre-select bits are now considered
	    281 		 * in 8 groups of 6 bits each.
	    282 		 * The 8 selection functions map these
	    283 		 * 6-bit quantities into 4-bit quantities
	    284 		 * and the results permuted
	    285 		 * to make an f(R, K).

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	    286 		 * The indexing into the selection functions
	    287 		 * is peculiar; it could be simplified by
	    288 		 * rewriting the tables.
	    289 		 */
	    290 		for (j=0; j<8; j++) {
	    291 			t = 6*j;
	    292 			k = S[j][(preS[t+0]<<5)+
	    293 				(preS[t+1]<<3)+
	    294 				(preS[t+2]<<2)+
	    295 				(preS[t+3]<<1)+
	    296 				(preS[t+4]<<0)+
	    297 				(preS[t+5]<<4)];
	    298 			t = 4*j;
	    299 			f[t+0] = (k>>3)&01;
	    300 			f[t+1] = (k>>2)&01;
	    301 			f[t+2] = (k>>1)&01;
	    302 			f[t+3] = (k>>0)&01;
	    303 		}
	    304 		/*
	    305 		 * The new R is L ^ f(R, K).
	    306 		 * The f here has to be permuted first, though.
	    307 		 */
	    308 		for (j=0; j<32; j++)
	    309 			R[j] = L[j] ^ f[P[j]-1];
	    310 		/*
	    311 		 * Finally, the new L (the original R)
	    312 		 * is copied back.
	    313 		 */
	    314 		for (j=0; j<32; j++)
	    315 			L[j] = tempL[j];
	    316 	}
	    317 	/*
	    318 	 * The output L and R are reversed.
	    319 	 */
	    320 	for (j=0; j<32; j++) {
	    321 		t = L[j];
	    322 		L[j] = R[j];
	    323 		R[j] = t;
	    324 	}
	    325 	/*
	    326 	 * The final output
	    327 	 * gets the inverse permutation of the very original.
	    328 	 */
	    329 	for (j=0; j<64; j++)
	    330 		block[j] = L[FP[j]-1];
	    331 }
	    332 
	    333 char *
	    334 crypt(pw,salt)
	    335 char *pw;
	    336 char *salt;
	    337 {
	    338 	register i, j, c;
	    339 	int temp;
	    340 	static char block[66], iobuf[16];
	    341 
	    342 	for(i=0; i<66; i++)

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	    343 		block[i] = 0;
	    344 	for(i=0; (c= *pw) && i<64; pw++){
	    345 		for(j=0; j<7; j++, i++)
	    346 			block[i] = (c>>(6-j)) & 01;
	    347 		i++;
	    348 	}
	    349 	
	    350 	setkey(block);
	    351 	
	    352 	for(i=0; i<66; i++)
	    353 		block[i] = 0;
	    354 
	    355 	for(i=0;i<2;i++){
	    356 		c = *salt++;
	    357 		iobuf[i] = c;
	    358 		if(c>'Z') c -= 6;
	    359 		if(c>'9') c -= 7;
	    360 		c -= '.';
	    361 		for(j=0;j<6;j++){
	    362 			if((c>>j) & 01){
	    363 				temp = E[6*i+j];
	    364 				E[6*i+j] = E[6*i+j+24];
	    365 				E[6*i+j+24] = temp;
	    366 				}
	    367 			}
	    368 		}
	    369 	
	    370 	for(i=0; i<25; i++)
	    371 		encrypt(block,0);
	    372 	
	    373 	for(i=0; i<11; i++){
	    374 		c = 0;
	    375 		for(j=0; j<6; j++){
	    376 			c <<= 1;
	    377 			c |= block[6*i+j];
	    378 			}
	    379 		c += '.';
	    380 		if(c>'9') c += 7;
	    381 		if(c>'Z') c += 6;
	    382 		iobuf[i+2] = c;
	    383 	}
	    384 	iobuf[i+2] = 0;
	    385 	if(iobuf[1]==0)
	    386 		iobuf[1] = iobuf[0];
	    387 	return(iobuf);
	    388 }


Command Line
------- ----

CC/NOANSI_ALIAS/ANALYSIS_DATA/ASSUME=(ACCURACY_SENSITIVE,ALIGNED_OBJECTS,WRITABLE_STRING_LITERALS)
/CROSS_REFERENCE/NOCOMMENTS/DIAGNOSTICS/DEBUG=(SYMBOLS,TRACEBACK/ENDIAN=LITTLE
/EXTERN_MODEL=RELAXED_REFDEF/FLOAT=(G_FLOAT)/GRANULARITY=QUADWORD/INSTRUCTION_SET=FLOATING_POINT
/LINE_CONTROL/L_DOUBLE_SIZE=128/LINE_DIRECTIVES/LIST/NOMACHINE_CODE/MEMBER_ALIGNMENT
/NAMES=UPPERCASE/NESTED_INCLUDE_DIRECTORY=INCLUDE_FILE/OBJECT/NOOPTIMIZE
/PREFIX=(ALL_ENTRIES)/PSECT_MODEL=NOMULTILANGUAGE/ROUNDING_MODE=NEAREST

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/SHOW=(HEADER,SOURCE)/SIGNED_CHAR/STANDARD=VAXC/REENTRANCY=TOLERANT/NOTRAP_UNINITIALIZED_VARIABLES
/WARNINGS
.