/* * $Source: /afs/athena.mit.edu/astaff/project/kerberos/src/lib/des/RCS/string_to_key.c,v $ * $Author: jtkohl $ * * Copyright 1985, 1986, 1987, 1988, 1989 by the Massachusetts Institute * of Technology. * * For copying and distribution information, please see the file * <mit-copyright.h>. * * These routines perform encryption and decryption using the DES * private key algorithm, or else a subset of it-- fewer inner loops. * (AUTH_DES_ITER defaults to 16, may be less.) * * Under U.S. law, this software may not be exported outside the US * without license from the U.S. Commerce department. * * The key schedule is passed as an arg, as well as the cleartext or * ciphertext. The cleartext and ciphertext should be in host order. * * These routines form the library interface to the DES facilities. * * spm 8/85 MIT project athena */ #ifndef lint static char rcsid_string_to_key_c[] = "$Id: string_to_key.c,v 4.11 90/01/02 13:46:38 jtkohl Exp $"; #endif lint #include <mit-copyright.h> #include <stdio.h> #include <des.h> #include "des_internal.h" extern int des_debug; extern int des_debug_print(); extern void des_fixup_key_parity(); /* * convert an arbitrary length string to a DES key */ int des_string_to_key(str,key) char *str; register des_cblock *key; { register char *in_str; register unsigned temp,i; register int j; register long length; static unsigned char *k_p; static int forward; register char *p_char; static char k_char[64]; static des_key_schedule key_sked; extern unsigned long des_cbc_cksum(); in_str = str; forward = 1; p_char = k_char; length = strlen(str); /* init key array for bits */ bzero(k_char,sizeof(k_char)); #ifdef DEBUG if (des_debug) fprintf(stdout, "\n\ninput str length = %d string = %s\nstring = 0x ", length,str); #endif /* get next 8 bytes, strip parity, xor */ for (i = 1; i <= length; i++) { /* get next input key byte */ temp = (unsigned int) *str++; #ifdef DEBUG if (des_debug) fprintf(stdout,"%02x ",temp & 0xff); #endif /* loop through bits within byte, ignore parity */ for (j = 0; j <= 6; j++) { if (forward) *p_char++ ^= (int) temp & 01; else *--p_char ^= (int) temp & 01; temp = temp >> 1; } while (--j > 0); /* check and flip direction */ if ((i%8) == 0) forward = !forward; } /* now stuff into the key des_cblock, and force odd parity */ p_char = k_char; k_p = (unsigned char *) key; for (i = 0; i <= 7; i++) { temp = 0; for (j = 0; j <= 6; j++) temp |= *p_char++ << (1+j); *k_p++ = (unsigned char) temp; } /* fix key parity */ des_fixup_key_parity(key); /* Now one-way encrypt it with the folded key */ (void) des_key_sched(key,key_sked); (void) des_cbc_cksum((des_cblock *)in_str,key,length,key_sked,key); /* erase key_sked */ bzero((char *)key_sked,sizeof(key_sked)); /* now fix up key parity again */ des_fixup_key_parity(key); if (des_debug) fprintf(stdout, "\nResulting string_to_key = 0x%x 0x%x\n", *((unsigned long *) key), *((unsigned long *) key+1)); }