/* vi: set sw=4 ts=4: */ /* * Copyright (C) 2001 by Rene M�ller * DES based crypt() implementation, originally written for dietlibc by * Rene M�ller, 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); }