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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* lib/crypto/des/string2key.c
*
* based on lib/crypto/des/string2key.c from MIT V5
* and on lib/des/afs_string_to_key.c from UMD.
* constructed by Mark Eichin, Cygnus Support, 1995.
* made thread-safe by Ken Raeburn, MIT, 2001.
*/
/*
* Copyright 2001 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
/*
* Copyright (C) 1998 by the FundsXpress, INC.
*
* All rights reserved.
*
* Export of this software from the United States of America may require
* a specific license from the United States Government. It is the
* responsibility of any person or organization contemplating export to
* obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of FundsXpress. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. FundsXpress makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#include "k5-int.h"
#include "des_int.h"
#include <ctype.h>
#define afs_crypt mit_afs_crypt
char *afs_crypt (const char *, const char *, char *);
#undef min
#define min(a,b) ((a)>(b)?(b):(a))
krb5_error_code
mit_afs_string_to_key(krb5_keyblock *keyblock, const krb5_data *data,
const krb5_data *salt)
{
/* totally different approach from MIT string2key. */
/* much of the work has already been done by the only caller
which is mit_des_string_to_key; in particular, *keyblock is already
set up. */
char *realm = salt->data;
unsigned int i, j;
krb5_octet *key = keyblock->contents;
if (data->length <= 8) {
/* One block only. Run afs_crypt and use the first eight
returned bytes after the copy of the (fixed) salt.
Since the returned bytes are alphanumeric, the output is
limited to 2**48 possibilities; for each byte, only 64
possible values can be used. */
unsigned char password[9]; /* trailing nul for crypt() */
char afs_crypt_buf[16];
memset (password, 0, sizeof (password));
memcpy (password, realm, min (salt->length, 8));
for (i=0; i<8; i++)
if (isupper(password[i]))
password[i] = tolower(password[i]);
for (i=0; i<data->length; i++)
password[i] ^= data->data[i];
for (i=0; i<8; i++)
if (password[i] == '\0')
password[i] = 'X';
password[8] = '\0';
/* Out-of-bounds salt characters are equivalent to a salt string
of "p1". */
strncpy((char *) key,
(char *) afs_crypt((char *) password, "#~", afs_crypt_buf) + 2,
8);
for (i=0; i<8; i++)
key[i] <<= 1;
/* now fix up key parity again */
mit_des_fixup_key_parity(key);
/* clean & free the input string */
memset(password, 0, (size_t) sizeof(password));
} else {
/* Multiple blocks. Do a CBC checksum, twice, and use the
result as the new key. */
mit_des_cblock ikey, tkey;
mit_des_key_schedule key_sked;
unsigned int pw_len = salt->length+data->length;
unsigned char *password = malloc(pw_len+1);
if (!password) return ENOMEM;
/* Some bound checks from the original code are elided here as
the malloc above makes sure we have enough storage. */
memcpy (password, data->data, data->length);
for (i=data->length, j = 0; j < salt->length; i++, j++) {
password[i] = realm[j];
if (isupper(password[i]))
password[i] = tolower(password[i]);
}
memcpy (ikey, "kerberos", sizeof(ikey));
memcpy (tkey, ikey, sizeof(tkey));
mit_des_fixup_key_parity (tkey);
(void) mit_des_key_sched (tkey, key_sked);
(void) mit_des_cbc_cksum (password, tkey, i, key_sked, ikey);
memcpy (ikey, tkey, sizeof(ikey));
mit_des_fixup_key_parity (tkey);
(void) mit_des_key_sched (tkey, key_sked);
(void) mit_des_cbc_cksum (password, key, i, key_sked, ikey);
/* erase key_sked */
memset(key_sked, 0,sizeof(key_sked));
/* now fix up key parity again */
mit_des_fixup_key_parity(key);
/* clean & free the input string */
memset(password, 0, (size_t) pw_len);
free(password);
}
#if 0
/* must free here because it was copied for this special case */
free(salt->data);
#endif
return 0;
}
/* Portions of this code:
Copyright 1989 by the Massachusetts Institute of Technology
*/
/*
* Copyright (c) 1990 Regents of The University of Michigan.
* All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this software
* and its documentation for any purpose and without fee is hereby
* granted, provided that the above copyright notice appears in all
* copies and that both that copyright notice and this permission
* notice appear in supporting documentation, and that the name of
* The University of Michigan not be used in advertising or
* publicity pertaining to distribution of the software without
* specific, written prior permission. This software is supplied as
* is without expressed or implied warranties of any kind.
*
* ITD Research Systems
* University of Michigan
* 535 W. William Street
* Ann Arbor, Michigan
* +1-313-936-2652
* netatalk@terminator.cc.umich.edu
*/
static void krb5_afs_crypt_setkey (char*, char*, char(*)[48]);
static void krb5_afs_encrypt (char*,char*,char (*)[48]);
/*
* Initial permutation,
*/
static const char IP[] = {
58,50,42,34,26,18,10, 2,
60,52,44,36,28,20,12, 4,
62,54,46,38,30,22,14, 6,
64,56,48,40,32,24,16, 8,
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,
};
/*
* Final permutation, FP = IP^(-1)
*/
static const char FP[] = {
40, 8,48,16,56,24,64,32,
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,
};
/*
* 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[] = {
57,49,41,33,25,17, 9,
1,58,50,42,34,26,18,
10, 2,59,51,43,35,27,
19,11, 3,60,52,44,36,
};
static const char PC1_D[] = {
63,55,47,39,31,23,15,
7,62,54,46,38,30,22,
14, 6,61,53,45,37,29,
21,13, 5,28,20,12, 4,
};
/*
* 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[] = {
14,17,11,24, 1, 5,
3,28,15, 6,21,10,
23,19,12, 4,26, 8,
16, 7,27,20,13, 2,
};
static const char PC2_D[] = {
41,52,31,37,47,55,
30,40,51,45,33,48,
44,49,39,56,34,53,
46,42,50,36,29,32,
};
/*
* The E bit-selection table.
*/
static const char e[] = {
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,
};
/*
* P is a permutation on the selected combination
* of the current L and key.
*/
static const char P[] = {
16, 7,20,21,
29,12,28,17,
1,15,23,26,
5,18,31,10,
2, 8,24,14,
32,27, 3, 9,
19,13,30, 6,
22,11, 4,25,
};
/*
* 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},
};
char *afs_crypt(const char *pw, const char *salt,
/* must be at least 16 bytes */
char *iobuf)
{
int i, j, c;
int temp;
char block[66];
char E[48];
/*
* The key schedule.
* Generated from the key.
*/
char KS[16][48];
for(i=0; i<66; i++)
block[i] = 0;
for(i=0; (c= *pw) && i<64; pw++){
for(j=0; j<7; j++, i++)
block[i] = (c>>(6-j)) & 01;
i++;
}
krb5_afs_crypt_setkey(block, E, KS);
for(i=0; i<66; i++)
block[i] = 0;
for(i=0;i<2;i++){
c = *salt++;
iobuf[i] = c;
if(c>'Z') c -= 6;
if(c>'9') c -= 7;
c -= '.';
for(j=0;j<6;j++){
if((c>>j) & 01){
temp = E[6*i+j];
E[6*i+j] = E[6*i+j+24];
E[6*i+j+24] = temp;
}
}
}
for(i=0; i<25; i++)
krb5_afs_encrypt(block,E,KS);
for(i=0; i<11; i++){
c = 0;
for(j=0; j<6; j++){
c <<= 1;
c |= block[6*i+j];
}
c += '.';
if(c>'9') c += 7;
if(c>'Z') c += 6;
iobuf[i+2] = c;
}
iobuf[i+2] = 0;
if(iobuf[1]==0)
iobuf[1] = iobuf[0];
return(iobuf);
}
/*
* Set up the key schedule from the key.
*/
static void krb5_afs_crypt_setkey(char *key, char *E, char (*KS)[48])
{
register int i, j, k;
int t;
/*
* The C and D arrays used to calculate the key schedule.
*/
char C[28], D[28];
/*
* 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++) {
C[i] = key[PC1_C[i]-1];
D[i] = key[PC1_D[i]-1];
}
/*
* To generate Ki, rotate C and D according
* to schedule and pick up a permutation
* using PC2.
*/
for (i=0; i<16; i++) {
/*
* rotate.
*/
for (k=0; k<shifts[i]; k++) {
t = C[0];
for (j=0; j<28-1; j++)
C[j] = C[j+1];
C[27] = t;
t = D[0];
for (j=0; j<28-1; j++)
D[j] = D[j+1];
D[27] = t;
}
/*
* get Ki. Note C and D are concatenated.
*/
for (j=0; j<24; j++) {
KS[i][j] = C[PC2_C[j]-1];
KS[i][j+24] = D[PC2_D[j]-28-1];
}
}
#if 0
for(i=0;i<48;i++) {
E[i] = e[i];
}
#else
memcpy(E, e, 48);
#endif
}
/*
* The payoff: encrypt a block.
*/
static void krb5_afs_encrypt(char *block, char *E, char (*KS)[48])
{
const long edflag = 0;
int i, ii;
int t, j, k;
char tempL[32];
char f[32];
/*
* The current block, divided into 2 halves.
*/
char L[64];
char *const R = &L[32];
/*
* The combination of the key and the input, before selection.
*/
char preS[48];
/*
* First, permute the bits in the input
*/
for (j=0; j<64; j++)
L[j] = block[IP[j]-1];
/*
* Perform an encryption operation 16 times.
*/
for (ii=0; ii<16; ii++) {
/*
* Set direction
*/
if (edflag)
i = 15-ii;
else
i = ii;
/*
* Save the R array,
* which will be the new L.
*/
#if 0
for (j=0; j<32; j++)
tempL[j] = R[j];
#else
memcpy(tempL, R, 32);
#endif
/*
* Expand R to 48 bits using the E selector;
* exclusive-or with the current key bits.
*/
for (j=0; j<48; j++)
preS[j] = R[E[j]-1] ^ 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 = 6*j;
k = S[j][(preS[t+0]<<5)+
(preS[t+1]<<3)+
(preS[t+2]<<2)+
(preS[t+3]<<1)+
(preS[t+4]<<0)+
(preS[t+5]<<4)];
t = 4*j;
f[t+0] = (k>>3)&01;
f[t+1] = (k>>2)&01;
f[t+2] = (k>>1)&01;
f[t+3] = (k>>0)&01;
}
/*
* The new R is L ^ f(R, K).
* The f here has to be permuted first, though.
*/
for (j=0; j<32; j++)
R[j] = L[j] ^ f[P[j]-1];
/*
* Finally, the new L (the original R)
* is copied back.
*/
#if 0
for (j=0; j<32; j++)
L[j] = tempL[j];
#else
memcpy(L, tempL, 32);
#endif
}
/*
* The output L and R are reversed.
*/
for (j=0; j<32; j++) {
t = L[j];
L[j] = R[j];
R[j] = t;
}
/*
* The final output
* gets the inverse permutation of the very original.
*/
for (j=0; j<64; j++)
block[j] = L[FP[j]-1];
}
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