From 08012e2446085d3d0873d6e882874d04d32e7cfe Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Thu, 19 Apr 2001 20:53:49 +0000 Subject: Add in a libcrypt implementation. About 8k. -Erik --- libcrypt/des.c | 330 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 330 insertions(+) create mode 100644 libcrypt/des.c (limited to 'libcrypt/des.c') diff --git a/libcrypt/des.c b/libcrypt/des.c new file mode 100644 index 000000000..e8a77c168 --- /dev/null +++ b/libcrypt/des.c @@ -0,0 +1,330 @@ +/* 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 +#include +#include + +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); +} + -- cgit v1.2.3