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+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright (C) 2001 by Rene Müller
+ * DES based crypt() implementation, originally written for dietlibc by
+ * Rene Müller, based on Bruce Schneier's Applied Cryptography, but
+ * tightened up quite a bit.
+ *
+ * Copyright (C) 2001 by Erik Andersen
+ * Adjusted each function to be reentrant, hacked in md5 support.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+
+
+#include <crypt.h>
+#include <string.h>
+#include <unistd.h>
+
+extern char *md5_magic;
+extern char * md5_crypt_r( const char *pw, const char *salt, struct crypt_data * data);
+
+/* Initial permutation, */
+static const char IP[] = {
+ 57,49,41,33,25,17, 9, 1,
+ 59,51,43,35,27,19,11, 3,
+ 61,53,45,37,29,21,13, 5,
+ 63,55,47,39,31,23,15, 7,
+ 56,48,40,32,24,16, 8, 0,
+ 58,50,42,34,26,18,10, 2,
+ 60,52,44,36,28,20,12, 4,
+ 62,54,46,38,30,22,14, 6
+};
+
+/* Final permutation, FP = IP^(-1) */
+static const char FP[] = {
+ 39, 7,47,15,55,23,63,31,
+ 38, 6,46,14,54,22,62,30,
+ 37, 5,45,13,53,21,61,29,
+ 36, 4,44,12,52,20,60,28,
+ 35, 3,43,11,51,19,59,27,
+ 34, 2,42,10,50,18,58,26,
+ 33, 1,41, 9,49,17,57,25,
+ 32, 0,40, 8,48,16,56,24
+};
+
+/* Permuted-choice 1 from the key bits to yield C and D.
+ * Note that bits 8,16... are left out: They are intended for a parity check.
+ */
+static const char PC1_C[] = {
+ 56,48,40,32,24,16, 8,
+ 0,57,49,41,33,25,17,
+ 9, 1,58,50,42,34,26,
+ 18,10, 2,59,51,43,35
+};
+
+static const char PC1_D[] = {
+ 62,54,46,38,30,22,14,
+ 6,61,53,45,37,29,21,
+ 13, 5,60,52,44,36,28,
+ 20,12, 4,27,19,11, 3
+};
+
+/* Sequence of shifts used for the key schedule. */
+static const char shifts[] = { 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1 };
+
+/*
+ * Permuted-choice 2, to pick out the bits from the CD array that generate
+ * the key schedule.
+ */
+static const char PC2_C[] = {
+ 13, 16, 10, 23, 0, 4, 2, 27, 14, 5, 20, 9,
+ 22, 18, 11, 3, 25, 7, 15, 6, 26, 19, 12, 1
+};
+
+static const char PC2_D[] = {
+ 12, 23, 2, 8, 18, 26, 1, 11, 22, 16, 4, 19,
+ 15, 20, 10, 27, 5, 24, 17, 13, 21, 7, 0, 3
+};
+
+static const char e2[] = {
+ 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9,
+ 8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17,
+ 16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25,
+ 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1
+};
+
+/* The 8 selection functions. For some reason, they give a 0-origin index,
+ * unlike everything else.
+ */
+static const char S[8][64] = {
+ {
+ 14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
+ 0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
+ 4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
+ 15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13
+ },
+
+ {
+ 15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
+ 3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
+ 0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
+ 13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9
+ },
+
+ {
+ 10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
+ 13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
+ 13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
+ 1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12
+ },
+
+ {
+ 7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
+ 13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
+ 10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
+ 3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14
+ },
+
+ {
+ 2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
+ 14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
+ 4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
+ 11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3
+ },
+
+ {
+ 12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
+ 10,15, 4, 2, 7,12, 9, 5, 6, 1,13,14, 0,11, 3, 8,
+ 9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
+ 4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13
+ },
+
+ {
+ 4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
+ 13, 0,11, 7, 4, 9, 1,10,14, 3, 5,12, 2,15, 8, 6,
+ 1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
+ 6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12
+ },
+
+ {
+ 13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
+ 1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
+ 7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
+ 2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11
+ }
+};
+
+/* P is a permutation on the selected combination of the current L and key. */
+static const char P[] = {
+ 15, 6,19,20, 28,11,27,16, 0,14,22,25, 4,17,30, 9,
+ 1, 7,23,13, 31,26, 2, 8, 18,12,29, 5, 21,10, 3,24
+};
+
+/* Set up the key schedule from the key. */
+void setkey_r(const char *key, struct crypt_data *data)
+{
+ register int i, j, k;
+ int t;
+ int s;
+
+ /* First, generate C and D by permuting the key. The low order bit of each
+ * 8-bit char is not used, so C and D are only 28 bits apiece.
+ */
+ for(i=0; i < 28; i++) {
+ data->C[i] = key[(int)PC1_C[i]];
+ data->D[i] = key[(int)PC1_D[i]];
+ }
+ /* To generate Ki, rotate C and D according to schedule and pick up a
+ * permutation using PC2.
+ */
+ for(i=0; i < 16; i++) {
+ /* rotate. */
+ s = shifts[i];
+ for(k=0; k < s; k++) {
+ t = data->C[0];
+ for(j=0; j < 27; j++)
+ data->C[j] = data->C[j+1];
+ data->C[27] = t;
+ t = data->D[0];
+ for(j=0; j < 27; j++)
+ data->D[j] = data->D[j+1];
+ data->D[27] = t;
+ }
+ /* get Ki. Note C and D are concatenated. */
+ for(j=0; j < 24; j++) {
+ data->KS[i][j] = data->C[(int)PC2_C[j]];
+ data->KS[i][j+24] = data->D[(int)PC2_D[j]];
+ }
+ }
+
+ for(i=0; i < 48; i++)
+ data->E[i] = e2[i];
+}
+
+
+/* The payoff: encrypt a block. */
+void encrypt_r(char block[64], int edflag, struct crypt_data *data)
+{
+ int i, ii;
+ register int t, j, k;
+
+ /* First, permute the bits in the input */
+ for(j=0; j < 64; j++)
+ data->L[j] = data->block[(int)IP[j]];
+ /* Perform an encryption operation 16 times. */
+ for(ii=0; ii < 16; ii++) {
+ i = ii;
+ /* Save the R array, which will be the new L. */
+ for(j=0; j < 32; j++)
+ data->tempL[j] = data->R[j];
+ /* Expand R to 48 bits using the E selector;
+ * exclusive-or with the current key bits.
+ */
+ for(j=0; j < 48; j++)
+ data->preS[j] = data->R[data->E[j]-1] ^ data->KS[i][j];
+ /* The pre-select bits are now considered in 8 groups of 6 bits each.
+ * The 8 selection functions map these 6-bit quantities into 4-bit
+ * quantities and the results permuted to make an f(R, K).
+ * The indexing into the selection functions is peculiar;
+ * it could be simplified by rewriting the tables.
+ */
+ for(j=0; j < 8; j++) {
+ t = ((j<<1)+j)<<1;
+ k = S[j][(data->preS[t]<<5)+
+ (data->preS[t+1]<<3)+
+ (data->preS[t+2]<<2)+
+ (data->preS[t+3]<<1)+
+ (data->preS[t+4] )+
+ (data->preS[t+5]<<4)];
+ t = j << 2;
+ data->f[t ] = (k>>3)&01;
+ data->f[t+1] = (k>>2)&01;
+ data->f[t+2] = (k>>1)&01;
+ data->f[t+3] = (k )&01;
+ }
+ /* The new R is L ^ f(R, K). The f here has to be permuted first, though. */
+ for(j=0; j < 32; j++)
+ data->R[j] = data->L[j] ^ data->f[(int)P[j]];
+ /* Finally, the new L (the original R) is copied back. */
+ for(j=0; j < 32; j++)
+ data->L[j] = data->tempL[j];
+ }
+ /* The output L and R are reversed. */
+ for(j=0; j < 32; j++) {
+ data->L[j] ^= data->R[j];
+ data->R[j] ^= data->L[j];
+ data->L[j] ^= data->R[j];
+ }
+ /* The final output gets the inverse permutation of the very original. */
+ for(j=0; j < 64; j++)
+ data->block[j] = data->L[(int)FP[j]];
+}
+
+char * crypt_r(const char *pw, const char *salt, struct crypt_data *data)
+{
+ register int i, j, c;
+
+
+ /* Check if we are supposed to be using the MD5 encryption replacement. */
+ if (strncmp (md5_magic, salt, sizeof (md5_magic) - 1) == 0)
+ return md5_crypt_r(pw, salt, data);
+
+ for(i=0; i < 66; i++)
+ data->block[i] = 0;
+ for(i=0; (c= *pw) && i < 64; pw++) {
+ for(j=0; j < 7; j++, i++)
+ data->block[i] = (c>>(6-j)) & 01;
+ i++;
+ }
+
+ setkey_r(data->block, data);
+
+ for(i=0; i < 66; i++)
+ data->block[i] = 0;
+
+ for(i=0; i < 2; i++) {
+ c = *salt++;
+ data->iobuf[i] = c;
+ if(c > 'Z')
+ c -= 6;
+ if(c > '9')
+ c -= 7;
+ c -= '.';
+ for(j=0; j < 6; j++) {
+ if((c>>j) & 01) {
+ int ind1 = (((i<<1)+i)<< 1) + j;
+ int ind2 = ind1 + 24;
+ data->E[ind1] ^= data->E[ind2];
+ data->E[ind2] ^= data->E[ind1];
+ data->E[ind1] ^= data->E[ind2];
+ }
+ }
+ }
+
+ for(i=0; i < 25; i++)
+ encrypt_r(data->block, 0, data);
+
+ for(i=0; i < 11; i++) {
+ c = 0;
+ for(j=0; j < 6; j++) {
+ c <<= 1;
+ c |= data->block[(((i<<1)+i)<<1)+j];
+ }
+ c += '.';
+ if(c > '9')
+ c += 7;
+ if(c > 'Z')
+ c += 6;
+ data->iobuf[i+2] = c;
+ }
+ data->iobuf[i+2] = 0;
+ if(data->iobuf[1] == 0)
+ data->iobuf[1] = data->iobuf[0];
+ return(data->iobuf);
+}
+
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