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1.1 root 1: #if defined(LIBC_SCCS) && !defined(lint)
2: static char sccsid[] = "@(#)crypt.c 5.2 (Berkeley) 3/9/86";
3: #endif LIBC_SCCS and not lint
4:
5: /*
6: * This program implements the
7: * Proposed Federal Information Processing
8: * Data Encryption Standard.
9: * See Federal Register, March 17, 1975 (40FR12134)
10: */
11:
12: /*
13: * Initial permutation,
14: */
15: static char IP[] = {
16: 58,50,42,34,26,18,10, 2,
17: 60,52,44,36,28,20,12, 4,
18: 62,54,46,38,30,22,14, 6,
19: 64,56,48,40,32,24,16, 8,
20: 57,49,41,33,25,17, 9, 1,
21: 59,51,43,35,27,19,11, 3,
22: 61,53,45,37,29,21,13, 5,
23: 63,55,47,39,31,23,15, 7,
24: };
25:
26: /*
27: * Final permutation, FP = IP^(-1)
28: */
29: static char FP[] = {
30: 40, 8,48,16,56,24,64,32,
31: 39, 7,47,15,55,23,63,31,
32: 38, 6,46,14,54,22,62,30,
33: 37, 5,45,13,53,21,61,29,
34: 36, 4,44,12,52,20,60,28,
35: 35, 3,43,11,51,19,59,27,
36: 34, 2,42,10,50,18,58,26,
37: 33, 1,41, 9,49,17,57,25,
38: };
39:
40: /*
41: * Permuted-choice 1 from the key bits
42: * to yield C and D.
43: * Note that bits 8,16... are left out:
44: * They are intended for a parity check.
45: */
46: static char PC1_C[] = {
47: 57,49,41,33,25,17, 9,
48: 1,58,50,42,34,26,18,
49: 10, 2,59,51,43,35,27,
50: 19,11, 3,60,52,44,36,
51: };
52:
53: static char PC1_D[] = {
54: 63,55,47,39,31,23,15,
55: 7,62,54,46,38,30,22,
56: 14, 6,61,53,45,37,29,
57: 21,13, 5,28,20,12, 4,
58: };
59:
60: /*
61: * Sequence of shifts used for the key schedule.
62: */
63: static char shifts[] = {
64: 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,
65: };
66:
67: /*
68: * Permuted-choice 2, to pick out the bits from
69: * the CD array that generate the key schedule.
70: */
71: static char PC2_C[] = {
72: 14,17,11,24, 1, 5,
73: 3,28,15, 6,21,10,
74: 23,19,12, 4,26, 8,
75: 16, 7,27,20,13, 2,
76: };
77:
78: static char PC2_D[] = {
79: 41,52,31,37,47,55,
80: 30,40,51,45,33,48,
81: 44,49,39,56,34,53,
82: 46,42,50,36,29,32,
83: };
84:
85: /*
86: * The C and D arrays used to calculate the key schedule.
87: */
88:
89: static char C[28];
90: static char D[28];
91: /*
92: * The key schedule.
93: * Generated from the key.
94: */
95: static char KS[16][48];
96:
97: /*
98: * The E bit-selection table.
99: */
100: static char E[48];
101: static char e[] = {
102: 32, 1, 2, 3, 4, 5,
103: 4, 5, 6, 7, 8, 9,
104: 8, 9,10,11,12,13,
105: 12,13,14,15,16,17,
106: 16,17,18,19,20,21,
107: 20,21,22,23,24,25,
108: 24,25,26,27,28,29,
109: 28,29,30,31,32, 1,
110: };
111:
112: /*
113: * Set up the key schedule from the key.
114: */
115:
116: setkey(key)
117: char *key;
118: {
119: register i, j, k;
120: int t;
121:
122: /*
123: * First, generate C and D by permuting
124: * the key. The low order bit of each
125: * 8-bit char is not used, so C and D are only 28
126: * bits apiece.
127: */
128: for (i=0; i<28; i++) {
129: C[i] = key[PC1_C[i]-1];
130: D[i] = key[PC1_D[i]-1];
131: }
132: /*
133: * To generate Ki, rotate C and D according
134: * to schedule and pick up a permutation
135: * using PC2.
136: */
137: for (i=0; i<16; i++) {
138: /*
139: * rotate.
140: */
141: for (k=0; k<shifts[i]; k++) {
142: t = C[0];
143: for (j=0; j<28-1; j++)
144: C[j] = C[j+1];
145: C[27] = t;
146: t = D[0];
147: for (j=0; j<28-1; j++)
148: D[j] = D[j+1];
149: D[27] = t;
150: }
151: /*
152: * get Ki. Note C and D are concatenated.
153: */
154: for (j=0; j<24; j++) {
155: KS[i][j] = C[PC2_C[j]-1];
156: KS[i][j+24] = D[PC2_D[j]-28-1];
157: }
158: }
159:
160: for(i=0;i<48;i++)
161: E[i] = e[i];
162: }
163:
164: /*
165: * The 8 selection functions.
166: * For some reason, they give a 0-origin
167: * index, unlike everything else.
168: */
169: static char S[8][64] = {
170: 14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
171: 0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
172: 4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
173: 15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13,
174:
175: 15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
176: 3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
177: 0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
178: 13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9,
179:
180: 10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
181: 13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
182: 13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
183: 1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12,
184:
185: 7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
186: 13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
187: 10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
188: 3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14,
189:
190: 2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
191: 14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
192: 4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
193: 11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3,
194:
195: 12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
196: 10,15, 4, 2, 7,12, 9, 5, 6, 1,13,14, 0,11, 3, 8,
197: 9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
198: 4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13,
199:
200: 4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
201: 13, 0,11, 7, 4, 9, 1,10,14, 3, 5,12, 2,15, 8, 6,
202: 1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
203: 6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12,
204:
205: 13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
206: 1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
207: 7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
208: 2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11,
209: };
210:
211: /*
212: * P is a permutation on the selected combination
213: * of the current L and key.
214: */
215: static char P[] = {
216: 16, 7,20,21,
217: 29,12,28,17,
218: 1,15,23,26,
219: 5,18,31,10,
220: 2, 8,24,14,
221: 32,27, 3, 9,
222: 19,13,30, 6,
223: 22,11, 4,25,
224: };
225:
226: /*
227: * The current block, divided into 2 halves.
228: */
229: static char L[32], R[32];
230: static char tempL[32];
231: static char f[32];
232:
233: /*
234: * The combination of the key and the input, before selection.
235: */
236: static char preS[48];
237:
238: /*
239: * The payoff: encrypt a block.
240: */
241:
242: encrypt(block, edflag)
243: char *block;
244: {
245: int i, ii;
246: register t, j, k;
247:
248: /*
249: * First, permute the bits in the input
250: */
251: for (j=0; j<64; j++)
252: L[j] = block[IP[j]-1];
253: /*
254: * Perform an encryption operation 16 times.
255: */
256: for (ii=0; ii<16; ii++) {
257: /*
258: * Set direction
259: */
260: if (edflag)
261: i = 15-ii;
262: else
263: i = ii;
264: /*
265: * Save the R array,
266: * which will be the new L.
267: */
268: for (j=0; j<32; j++)
269: tempL[j] = R[j];
270: /*
271: * Expand R to 48 bits using the E selector;
272: * exclusive-or with the current key bits.
273: */
274: for (j=0; j<48; j++)
275: preS[j] = R[E[j]-1] ^ KS[i][j];
276: /*
277: * The pre-select bits are now considered
278: * in 8 groups of 6 bits each.
279: * The 8 selection functions map these
280: * 6-bit quantities into 4-bit quantities
281: * and the results permuted
282: * to make an f(R, K).
283: * The indexing into the selection functions
284: * is peculiar; it could be simplified by
285: * rewriting the tables.
286: */
287: for (j=0; j<8; j++) {
288: t = 6*j;
289: k = S[j][(preS[t+0]<<5)+
290: (preS[t+1]<<3)+
291: (preS[t+2]<<2)+
292: (preS[t+3]<<1)+
293: (preS[t+4]<<0)+
294: (preS[t+5]<<4)];
295: t = 4*j;
296: f[t+0] = (k>>3)&01;
297: f[t+1] = (k>>2)&01;
298: f[t+2] = (k>>1)&01;
299: f[t+3] = (k>>0)&01;
300: }
301: /*
302: * The new R is L ^ f(R, K).
303: * The f here has to be permuted first, though.
304: */
305: for (j=0; j<32; j++)
306: R[j] = L[j] ^ f[P[j]-1];
307: /*
308: * Finally, the new L (the original R)
309: * is copied back.
310: */
311: for (j=0; j<32; j++)
312: L[j] = tempL[j];
313: }
314: /*
315: * The output L and R are reversed.
316: */
317: for (j=0; j<32; j++) {
318: t = L[j];
319: L[j] = R[j];
320: R[j] = t;
321: }
322: /*
323: * The final output
324: * gets the inverse permutation of the very original.
325: */
326: for (j=0; j<64; j++)
327: block[j] = L[FP[j]-1];
328: }
329:
330: char *
331: crypt(pw,salt)
332: char *pw;
333: char *salt;
334: {
335: register i, j, c;
336: int temp;
337: static char block[66], iobuf[16];
338:
339: for(i=0; i<66; i++)
340: block[i] = 0;
341: for(i=0; (c= *pw) && i<64; pw++){
342: for(j=0; j<7; j++, i++)
343: block[i] = (c>>(6-j)) & 01;
344: i++;
345: }
346:
347: setkey(block);
348:
349: for(i=0; i<66; i++)
350: block[i] = 0;
351:
352: for(i=0;i<2;i++){
353: c = *salt++;
354: iobuf[i] = c;
355: if(c>'Z') c -= 6;
356: if(c>'9') c -= 7;
357: c -= '.';
358: for(j=0;j<6;j++){
359: if((c>>j) & 01){
360: temp = E[6*i+j];
361: E[6*i+j] = E[6*i+j+24];
362: E[6*i+j+24] = temp;
363: }
364: }
365: }
366:
367: for(i=0; i<25; i++)
368: encrypt(block,0);
369:
370: for(i=0; i<11; i++){
371: c = 0;
372: for(j=0; j<6; j++){
373: c <<= 1;
374: c |= block[6*i+j];
375: }
376: c += '.';
377: if(c>'9') c += 7;
378: if(c>'Z') c += 6;
379: iobuf[i+2] = c;
380: }
381: iobuf[i+2] = 0;
382: if(iobuf[1]==0)
383: iobuf[1] = iobuf[0];
384: return(iobuf);
385: }
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