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1.1 root 1: /* @(#)crypt.c 4.1 (Berkeley) 12/21/80 */
2: /*
3: * This program implements the
4: * Proposed Federal Information Processing
5: * Data Encryption Standard.
6: * See Federal Register, March 17, 1975 (40FR12134)
7: */
8:
9: /*
10: * Initial permutation,
11: */
12: static char IP[] = {
13: 58,50,42,34,26,18,10, 2,
14: 60,52,44,36,28,20,12, 4,
15: 62,54,46,38,30,22,14, 6,
16: 64,56,48,40,32,24,16, 8,
17: 57,49,41,33,25,17, 9, 1,
18: 59,51,43,35,27,19,11, 3,
19: 61,53,45,37,29,21,13, 5,
20: 63,55,47,39,31,23,15, 7,
21: };
22:
23: /*
24: * Final permutation, FP = IP^(-1)
25: */
26: static char FP[] = {
27: 40, 8,48,16,56,24,64,32,
28: 39, 7,47,15,55,23,63,31,
29: 38, 6,46,14,54,22,62,30,
30: 37, 5,45,13,53,21,61,29,
31: 36, 4,44,12,52,20,60,28,
32: 35, 3,43,11,51,19,59,27,
33: 34, 2,42,10,50,18,58,26,
34: 33, 1,41, 9,49,17,57,25,
35: };
36:
37: /*
38: * Permuted-choice 1 from the key bits
39: * to yield C and D.
40: * Note that bits 8,16... are left out:
41: * They are intended for a parity check.
42: */
43: static char PC1_C[] = {
44: 57,49,41,33,25,17, 9,
45: 1,58,50,42,34,26,18,
46: 10, 2,59,51,43,35,27,
47: 19,11, 3,60,52,44,36,
48: };
49:
50: static char PC1_D[] = {
51: 63,55,47,39,31,23,15,
52: 7,62,54,46,38,30,22,
53: 14, 6,61,53,45,37,29,
54: 21,13, 5,28,20,12, 4,
55: };
56:
57: /*
58: * Sequence of shifts used for the key schedule.
59: */
60: static char shifts[] = {
61: 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,
62: };
63:
64: /*
65: * Permuted-choice 2, to pick out the bits from
66: * the CD array that generate the key schedule.
67: */
68: static char PC2_C[] = {
69: 14,17,11,24, 1, 5,
70: 3,28,15, 6,21,10,
71: 23,19,12, 4,26, 8,
72: 16, 7,27,20,13, 2,
73: };
74:
75: static char PC2_D[] = {
76: 41,52,31,37,47,55,
77: 30,40,51,45,33,48,
78: 44,49,39,56,34,53,
79: 46,42,50,36,29,32,
80: };
81:
82: /*
83: * The C and D arrays used to calculate the key schedule.
84: */
85:
86: static char C[28];
87: static char D[28];
88: /*
89: * The key schedule.
90: * Generated from the key.
91: */
92: static char KS[16][48];
93:
94: /*
95: * Set up the key schedule from the key.
96: */
97:
98: setkey(key)
99: char *key;
100: {
101: register i, j, k;
102: int t;
103:
104: /*
105: * First, generate C and D by permuting
106: * the key. The low order bit of each
107: * 8-bit char is not used, so C and D are only 28
108: * bits apiece.
109: */
110: for (i=0; i<28; i++) {
111: C[i] = key[PC1_C[i]-1];
112: D[i] = key[PC1_D[i]-1];
113: }
114: /*
115: * To generate Ki, rotate C and D according
116: * to schedule and pick up a permutation
117: * using PC2.
118: */
119: for (i=0; i<16; i++) {
120: /*
121: * rotate.
122: */
123: for (k=0; k<shifts[i]; k++) {
124: t = C[0];
125: for (j=0; j<28-1; j++)
126: C[j] = C[j+1];
127: C[27] = t;
128: t = D[0];
129: for (j=0; j<28-1; j++)
130: D[j] = D[j+1];
131: D[27] = t;
132: }
133: /*
134: * get Ki. Note C and D are concatenated.
135: */
136: for (j=0; j<24; j++) {
137: KS[i][j] = C[PC2_C[j]-1];
138: KS[i][j+24] = D[PC2_D[j]-28-1];
139: }
140: }
141: }
142:
143: /*
144: * The E bit-selection table.
145: */
146: static char E[48];
147: static char e[] = {
148: 32, 1, 2, 3, 4, 5,
149: 4, 5, 6, 7, 8, 9,
150: 8, 9,10,11,12,13,
151: 12,13,14,15,16,17,
152: 16,17,18,19,20,21,
153: 20,21,22,23,24,25,
154: 24,25,26,27,28,29,
155: 28,29,30,31,32, 1,
156: };
157:
158: /*
159: * The 8 selection functions.
160: * For some reason, they give a 0-origin
161: * index, unlike everything else.
162: */
163: static char S[8][64] = {
164: 14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
165: 0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
166: 4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
167: 15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13,
168:
169: 15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
170: 3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
171: 0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
172: 13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9,
173:
174: 10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
175: 13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
176: 13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
177: 1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12,
178:
179: 7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
180: 13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
181: 10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
182: 3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14,
183:
184: 2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
185: 14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
186: 4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
187: 11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3,
188:
189: 12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
190: 10,15, 4, 2, 7,12, 9, 5, 6, 1,13,14, 0,11, 3, 8,
191: 9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
192: 4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13,
193:
194: 4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
195: 13, 0,11, 7, 4, 9, 1,10,14, 3, 5,12, 2,15, 8, 6,
196: 1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
197: 6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12,
198:
199: 13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
200: 1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
201: 7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
202: 2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11,
203: };
204:
205: /*
206: * P is a permutation on the selected combination
207: * of the current L and key.
208: */
209: static char P[] = {
210: 16, 7,20,21,
211: 29,12,28,17,
212: 1,15,23,26,
213: 5,18,31,10,
214: 2, 8,24,14,
215: 32,27, 3, 9,
216: 19,13,30, 6,
217: 22,11, 4,25,
218: };
219:
220: /*
221: * The current block, divided into 2 halves.
222: */
223: static char L[32], R[32];
224: static char tempL[32];
225: static char f[32];
226:
227: /*
228: * The combination of the key and the input, before selection.
229: */
230: static char preS[48];
231:
232: /*
233: * The payoff: encrypt a block.
234: */
235:
236: encrypt(block, edflag)
237: char *block;
238: {
239: int i, ii;
240: register t, j, k;
241:
242: /*
243: * First, permute the bits in the input
244: */
245: for (j=0; j<64; j++)
246: L[j] = block[IP[j]-1];
247: /*
248: * Perform an encryption operation 16 times.
249: */
250: for (ii=0; ii<16; ii++) {
251: /*
252: * Set direction
253: */
254: if (edflag)
255: i = 15-ii;
256: else
257: i = ii;
258: /*
259: * Save the R array,
260: * which will be the new L.
261: */
262: for (j=0; j<32; j++)
263: tempL[j] = R[j];
264: /*
265: * Expand R to 48 bits using the E selector;
266: * exclusive-or with the current key bits.
267: */
268: for (j=0; j<48; j++)
269: preS[j] = R[E[j]-1] ^ KS[i][j];
270: /*
271: * The pre-select bits are now considered
272: * in 8 groups of 6 bits each.
273: * The 8 selection functions map these
274: * 6-bit quantities into 4-bit quantities
275: * and the results permuted
276: * to make an f(R, K).
277: * The indexing into the selection functions
278: * is peculiar; it could be simplified by
279: * rewriting the tables.
280: */
281: for (j=0; j<8; j++) {
282: t = 6*j;
283: k = S[j][(preS[t+0]<<5)+
284: (preS[t+1]<<3)+
285: (preS[t+2]<<2)+
286: (preS[t+3]<<1)+
287: (preS[t+4]<<0)+
288: (preS[t+5]<<4)];
289: t = 4*j;
290: f[t+0] = (k>>3)&01;
291: f[t+1] = (k>>2)&01;
292: f[t+2] = (k>>1)&01;
293: f[t+3] = (k>>0)&01;
294: }
295: /*
296: * The new R is L ^ f(R, K).
297: * The f here has to be permuted first, though.
298: */
299: for (j=0; j<32; j++)
300: R[j] = L[j] ^ f[P[j]-1];
301: /*
302: * Finally, the new L (the original R)
303: * is copied back.
304: */
305: for (j=0; j<32; j++)
306: L[j] = tempL[j];
307: }
308: /*
309: * The output L and R are reversed.
310: */
311: for (j=0; j<32; j++) {
312: t = L[j];
313: L[j] = R[j];
314: R[j] = t;
315: }
316: /*
317: * The final output
318: * gets the inverse permutation of the very original.
319: */
320: for (j=0; j<64; j++)
321: block[j] = L[FP[j]-1];
322: }
323:
324: char *
325: crypt(pw,salt)
326: char *pw;
327: char *salt;
328: {
329: register i, j, c;
330: int temp;
331: static char block[66], iobuf[16];
332: for(i=0; i<66; i++)
333: block[i] = 0;
334: for(i=0; (c= *pw) && i<64; pw++){
335: for(j=0; j<7; j++, i++)
336: block[i] = (c>>(6-j)) & 01;
337: i++;
338: }
339:
340: setkey(block);
341:
342: for(i=0; i<66; i++)
343: block[i] = 0;
344:
345: for(i=0;i<48;i++)
346: E[i] = e[i];
347:
348: for(i=0;i<2;i++){
349: c = *salt++;
350: iobuf[i] = c;
351: if(c>'Z') c -= 6;
352: if(c>'9') c -= 7;
353: c -= '.';
354: for(j=0;j<6;j++){
355: if((c>>j) & 01){
356: temp = E[6*i+j];
357: E[6*i+j] = E[6*i+j+24];
358: E[6*i+j+24] = temp;
359: }
360: }
361: }
362:
363: for(i=0; i<25; i++)
364: encrypt(block,0);
365:
366: for(i=0; i<11; i++){
367: c = 0;
368: for(j=0; j<6; j++){
369: c <<= 1;
370: c |= block[6*i+j];
371: }
372: c += '.';
373: if(c>'9') c += 7;
374: if(c>'Z') c += 6;
375: iobuf[i+2] = c;
376: }
377: iobuf[i+2] = 0;
378: if(iobuf[1]==0)
379: iobuf[1] = iobuf[0];
380: return(iobuf);
381: }
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