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/*
Copyright (C) 1997,1998 Dimitrios P. Bouras
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., 675 Mass Ave, Cambridge, MA 02139, USA.
For author contact information, look in the README file.
*/
/* Password encryption/decryption data structures and routines */
static unsigned char pkey[8] = {0x87,0xB6,0xAC,0xAF,0xC6,0xC8,0x94,0x8C},
ukey[64], upwd[64];
/* Initializes the pcode module */
void pcode_init(void)
{
int i;
for (i=0; i<8; i++) /* since we don't want it sticking around */
pkey[i] ^= 0xFF; /* as plain text in the executable ;) */
}
/* Packs 64 bits saved in array of char into 8 bytes */
static void cpack(unsigned char *pb, unsigned char *ub)
{
int i,j;
unsigned char mask, pc;
for (i=0; i<8; i++) {
for (mask=0x80, pc=j=0; j<8; mask>>=1, j++) {
pc |= (ub[i*8+j])? mask:0x00;
}
pb[i] = pc;
}
}
/* Unpacks 8 bytes into 64 bits saved in array of char */
static void cupack(unsigned char *ub, unsigned char *pb)
{
int i,j;
for (i=0; i<8; i++) {
for (j=0; j<8; j++) {
ub[i*8+j] = (pb[i] & (0x80>>j)) ? 1:0;
}
}
}
/* Encrypts the plain-text password */
void pencode(unsigned char *ep, unsigned char *pp)
{
int i;
void setkey(), encrypt();
cupack(ukey, pkey); /* unpack the key */
setkey(ukey); /* insert it in crypt's machine */
for (i=0; i<4; i++) { /* do all 32 bytes */
cupack(upwd, pp); /* unpack the plain-text password */
encrypt(upwd, 0); /* encrypt it in place */
cpack(ep, upwd); /* copy it out into the result */
ep += 8; pp += 8; /* get next 8 bytes */
}
}
/* Decrypts the password */
void pdecode(unsigned char *pp, unsigned char *ep)
{
int i;
void setkey(), encrypt();
cupack(ukey, pkey); /* unpack the key */
setkey(ukey); /* insert it in crypt's machine */
for (i=0; i<4; i++) { /* do all 32 bytes */
cupack(upwd, ep); /* unpack the encrypted password */
encrypt(upwd, 1); /* decrypt it in place */
cpack(pp, upwd); /* copy it out into the result */
ep += 8; pp += 8; /* get next 8 bytes */
}
}
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