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v4.6
  1/*
  2 * COPYRIGHT (c) 2008
  3 * The Regents of the University of Michigan
  4 * ALL RIGHTS RESERVED
  5 *
  6 * Permission is granted to use, copy, create derivative works
  7 * and redistribute this software and such derivative works
  8 * for any purpose, so long as the name of The University of
  9 * Michigan is not used in any advertising or publicity
 10 * pertaining to the use of distribution of this software
 11 * without specific, written prior authorization.  If the
 12 * above copyright notice or any other identification of the
 13 * University of Michigan is included in any copy of any
 14 * portion of this software, then the disclaimer below must
 15 * also be included.
 16 *
 17 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
 18 * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
 19 * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
 20 * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
 21 * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
 22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
 23 * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
 24 * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
 25 * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
 26 * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
 27 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
 28 * SUCH DAMAGES.
 29 */
 30
 31/*
 32 * Copyright (C) 1998 by the FundsXpress, INC.
 33 *
 34 * All rights reserved.
 35 *
 36 * Export of this software from the United States of America may require
 37 * a specific license from the United States Government.  It is the
 38 * responsibility of any person or organization contemplating export to
 39 * obtain such a license before exporting.
 40 *
 41 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 42 * distribute this software and its documentation for any purpose and
 43 * without fee is hereby granted, provided that the above copyright
 44 * notice appear in all copies and that both that copyright notice and
 45 * this permission notice appear in supporting documentation, and that
 46 * the name of FundsXpress. not be used in advertising or publicity pertaining
 47 * to distribution of the software without specific, written prior
 48 * permission.  FundsXpress makes no representations about the suitability of
 49 * this software for any purpose.  It is provided "as is" without express
 50 * or implied warranty.
 51 *
 52 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 53 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 54 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 55 */
 56
 57#include <crypto/skcipher.h>
 58#include <linux/err.h>
 59#include <linux/types.h>
 60#include <linux/sunrpc/gss_krb5.h>
 61#include <linux/sunrpc/xdr.h>
 62#include <linux/lcm.h>
 63
 64#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 65# define RPCDBG_FACILITY        RPCDBG_AUTH
 66#endif
 67
 68/*
 69 * This is the n-fold function as described in rfc3961, sec 5.1
 70 * Taken from MIT Kerberos and modified.
 71 */
 72
 73static void krb5_nfold(u32 inbits, const u8 *in,
 74		       u32 outbits, u8 *out)
 75{
 76	unsigned long ulcm;
 77	int byte, i, msbit;
 78
 79	/* the code below is more readable if I make these bytes
 80	   instead of bits */
 81
 82	inbits >>= 3;
 83	outbits >>= 3;
 84
 85	/* first compute lcm(n,k) */
 86	ulcm = lcm(inbits, outbits);
 87
 88	/* now do the real work */
 89
 90	memset(out, 0, outbits);
 91	byte = 0;
 92
 93	/* this will end up cycling through k lcm(k,n)/k times, which
 94	   is correct */
 95	for (i = ulcm-1; i >= 0; i--) {
 96		/* compute the msbit in k which gets added into this byte */
 97		msbit = (
 98			/* first, start with the msbit in the first,
 99			 * unrotated byte */
100			 ((inbits << 3) - 1)
101			 /* then, for each byte, shift to the right
102			  * for each repetition */
103			 + (((inbits << 3) + 13) * (i/inbits))
104			 /* last, pick out the correct byte within
105			  * that shifted repetition */
106			 + ((inbits - (i % inbits)) << 3)
107			 ) % (inbits << 3);
108
109		/* pull out the byte value itself */
110		byte += (((in[((inbits - 1) - (msbit >> 3)) % inbits] << 8)|
111				  (in[((inbits) - (msbit >> 3)) % inbits]))
112				 >> ((msbit & 7) + 1)) & 0xff;
113
114		/* do the addition */
115		byte += out[i % outbits];
116		out[i % outbits] = byte & 0xff;
117
118		/* keep around the carry bit, if any */
119		byte >>= 8;
120
121	}
122
123	/* if there's a carry bit left over, add it back in */
124	if (byte) {
125		for (i = outbits - 1; i >= 0; i--) {
126			/* do the addition */
127			byte += out[i];
128			out[i] = byte & 0xff;
129
130			/* keep around the carry bit, if any */
131			byte >>= 8;
132		}
133	}
134}
135
136/*
137 * This is the DK (derive_key) function as described in rfc3961, sec 5.1
138 * Taken from MIT Kerberos and modified.
139 */
140
141u32 krb5_derive_key(const struct gss_krb5_enctype *gk5e,
142		    const struct xdr_netobj *inkey,
143		    struct xdr_netobj *outkey,
144		    const struct xdr_netobj *in_constant,
145		    gfp_t gfp_mask)
146{
147	size_t blocksize, keybytes, keylength, n;
148	unsigned char *inblockdata, *outblockdata, *rawkey;
149	struct xdr_netobj inblock, outblock;
150	struct crypto_skcipher *cipher;
151	u32 ret = EINVAL;
152
153	blocksize = gk5e->blocksize;
154	keybytes = gk5e->keybytes;
155	keylength = gk5e->keylength;
156
157	if ((inkey->len != keylength) || (outkey->len != keylength))
158		goto err_return;
159
160	cipher = crypto_alloc_skcipher(gk5e->encrypt_name, 0,
161				       CRYPTO_ALG_ASYNC);
162	if (IS_ERR(cipher))
163		goto err_return;
164	if (crypto_skcipher_setkey(cipher, inkey->data, inkey->len))
165		goto err_return;
166
167	/* allocate and set up buffers */
168
169	ret = ENOMEM;
170	inblockdata = kmalloc(blocksize, gfp_mask);
171	if (inblockdata == NULL)
172		goto err_free_cipher;
173
174	outblockdata = kmalloc(blocksize, gfp_mask);
175	if (outblockdata == NULL)
176		goto err_free_in;
177
178	rawkey = kmalloc(keybytes, gfp_mask);
179	if (rawkey == NULL)
180		goto err_free_out;
181
182	inblock.data = (char *) inblockdata;
183	inblock.len = blocksize;
184
185	outblock.data = (char *) outblockdata;
186	outblock.len = blocksize;
187
188	/* initialize the input block */
189
190	if (in_constant->len == inblock.len) {
191		memcpy(inblock.data, in_constant->data, inblock.len);
192	} else {
193		krb5_nfold(in_constant->len * 8, in_constant->data,
194			   inblock.len * 8, inblock.data);
195	}
196
197	/* loop encrypting the blocks until enough key bytes are generated */
198
199	n = 0;
200	while (n < keybytes) {
201		(*(gk5e->encrypt))(cipher, NULL, inblock.data,
202				   outblock.data, inblock.len);
203
204		if ((keybytes - n) <= outblock.len) {
205			memcpy(rawkey + n, outblock.data, (keybytes - n));
206			break;
207		}
208
209		memcpy(rawkey + n, outblock.data, outblock.len);
210		memcpy(inblock.data, outblock.data, outblock.len);
211		n += outblock.len;
212	}
213
214	/* postprocess the key */
215
216	inblock.data = (char *) rawkey;
217	inblock.len = keybytes;
218
219	BUG_ON(gk5e->mk_key == NULL);
220	ret = (*(gk5e->mk_key))(gk5e, &inblock, outkey);
221	if (ret) {
222		dprintk("%s: got %d from mk_key function for '%s'\n",
223			__func__, ret, gk5e->encrypt_name);
224		goto err_free_raw;
225	}
226
227	/* clean memory, free resources and exit */
228
229	ret = 0;
230
231err_free_raw:
232	memset(rawkey, 0, keybytes);
233	kfree(rawkey);
234err_free_out:
235	memset(outblockdata, 0, blocksize);
236	kfree(outblockdata);
237err_free_in:
238	memset(inblockdata, 0, blocksize);
239	kfree(inblockdata);
240err_free_cipher:
241	crypto_free_skcipher(cipher);
242err_return:
243	return ret;
244}
245
246#define smask(step) ((1<<step)-1)
247#define pstep(x, step) (((x)&smask(step))^(((x)>>step)&smask(step)))
248#define parity_char(x) pstep(pstep(pstep((x), 4), 2), 1)
249
250static void mit_des_fixup_key_parity(u8 key[8])
251{
252	int i;
253	for (i = 0; i < 8; i++) {
254		key[i] &= 0xfe;
255		key[i] |= 1^parity_char(key[i]);
256	}
257}
258
259/*
260 * This is the des3 key derivation postprocess function
261 */
262u32 gss_krb5_des3_make_key(const struct gss_krb5_enctype *gk5e,
263			   struct xdr_netobj *randombits,
264			   struct xdr_netobj *key)
265{
266	int i;
267	u32 ret = EINVAL;
268
269	if (key->len != 24) {
270		dprintk("%s: key->len is %d\n", __func__, key->len);
271		goto err_out;
272	}
273	if (randombits->len != 21) {
274		dprintk("%s: randombits->len is %d\n",
275			__func__, randombits->len);
276		goto err_out;
277	}
278
279	/* take the seven bytes, move them around into the top 7 bits of the
280	   8 key bytes, then compute the parity bits.  Do this three times. */
281
282	for (i = 0; i < 3; i++) {
283		memcpy(key->data + i*8, randombits->data + i*7, 7);
284		key->data[i*8+7] = (((key->data[i*8]&1)<<1) |
285				    ((key->data[i*8+1]&1)<<2) |
286				    ((key->data[i*8+2]&1)<<3) |
287				    ((key->data[i*8+3]&1)<<4) |
288				    ((key->data[i*8+4]&1)<<5) |
289				    ((key->data[i*8+5]&1)<<6) |
290				    ((key->data[i*8+6]&1)<<7));
291
292		mit_des_fixup_key_parity(key->data + i*8);
293	}
294	ret = 0;
295err_out:
296	return ret;
297}
298
299/*
300 * This is the aes key derivation postprocess function
301 */
302u32 gss_krb5_aes_make_key(const struct gss_krb5_enctype *gk5e,
303			  struct xdr_netobj *randombits,
304			  struct xdr_netobj *key)
305{
306	u32 ret = EINVAL;
307
308	if (key->len != 16 && key->len != 32) {
309		dprintk("%s: key->len is %d\n", __func__, key->len);
310		goto err_out;
311	}
312	if (randombits->len != 16 && randombits->len != 32) {
313		dprintk("%s: randombits->len is %d\n",
314			__func__, randombits->len);
315		goto err_out;
316	}
317	if (randombits->len != key->len) {
318		dprintk("%s: randombits->len is %d, key->len is %d\n",
319			__func__, randombits->len, key->len);
320		goto err_out;
321	}
322	memcpy(key->data, randombits->data, key->len);
323	ret = 0;
324err_out:
325	return ret;
326}
327
v5.4
  1/*
  2 * COPYRIGHT (c) 2008
  3 * The Regents of the University of Michigan
  4 * ALL RIGHTS RESERVED
  5 *
  6 * Permission is granted to use, copy, create derivative works
  7 * and redistribute this software and such derivative works
  8 * for any purpose, so long as the name of The University of
  9 * Michigan is not used in any advertising or publicity
 10 * pertaining to the use of distribution of this software
 11 * without specific, written prior authorization.  If the
 12 * above copyright notice or any other identification of the
 13 * University of Michigan is included in any copy of any
 14 * portion of this software, then the disclaimer below must
 15 * also be included.
 16 *
 17 * THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION
 18 * FROM THE UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY
 19 * PURPOSE, AND WITHOUT WARRANTY BY THE UNIVERSITY OF
 20 * MICHIGAN OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING
 21 * WITHOUT LIMITATION THE IMPLIED WARRANTIES OF
 22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
 23 * REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE LIABLE
 24 * FOR ANY DAMAGES, INCLUDING SPECIAL, INDIRECT, INCIDENTAL, OR
 25 * CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM ARISING
 26 * OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
 27 * IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF
 28 * SUCH DAMAGES.
 29 */
 30
 31/*
 32 * Copyright (C) 1998 by the FundsXpress, INC.
 33 *
 34 * All rights reserved.
 35 *
 36 * Export of this software from the United States of America may require
 37 * a specific license from the United States Government.  It is the
 38 * responsibility of any person or organization contemplating export to
 39 * obtain such a license before exporting.
 40 *
 41 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 42 * distribute this software and its documentation for any purpose and
 43 * without fee is hereby granted, provided that the above copyright
 44 * notice appear in all copies and that both that copyright notice and
 45 * this permission notice appear in supporting documentation, and that
 46 * the name of FundsXpress. not be used in advertising or publicity pertaining
 47 * to distribution of the software without specific, written prior
 48 * permission.  FundsXpress makes no representations about the suitability of
 49 * this software for any purpose.  It is provided "as is" without express
 50 * or implied warranty.
 51 *
 52 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 53 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 54 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 55 */
 56
 57#include <crypto/skcipher.h>
 58#include <linux/err.h>
 59#include <linux/types.h>
 60#include <linux/sunrpc/gss_krb5.h>
 61#include <linux/sunrpc/xdr.h>
 62#include <linux/lcm.h>
 63
 64#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 65# define RPCDBG_FACILITY        RPCDBG_AUTH
 66#endif
 67
 68/*
 69 * This is the n-fold function as described in rfc3961, sec 5.1
 70 * Taken from MIT Kerberos and modified.
 71 */
 72
 73static void krb5_nfold(u32 inbits, const u8 *in,
 74		       u32 outbits, u8 *out)
 75{
 76	unsigned long ulcm;
 77	int byte, i, msbit;
 78
 79	/* the code below is more readable if I make these bytes
 80	   instead of bits */
 81
 82	inbits >>= 3;
 83	outbits >>= 3;
 84
 85	/* first compute lcm(n,k) */
 86	ulcm = lcm(inbits, outbits);
 87
 88	/* now do the real work */
 89
 90	memset(out, 0, outbits);
 91	byte = 0;
 92
 93	/* this will end up cycling through k lcm(k,n)/k times, which
 94	   is correct */
 95	for (i = ulcm-1; i >= 0; i--) {
 96		/* compute the msbit in k which gets added into this byte */
 97		msbit = (
 98			/* first, start with the msbit in the first,
 99			 * unrotated byte */
100			 ((inbits << 3) - 1)
101			 /* then, for each byte, shift to the right
102			  * for each repetition */
103			 + (((inbits << 3) + 13) * (i/inbits))
104			 /* last, pick out the correct byte within
105			  * that shifted repetition */
106			 + ((inbits - (i % inbits)) << 3)
107			 ) % (inbits << 3);
108
109		/* pull out the byte value itself */
110		byte += (((in[((inbits - 1) - (msbit >> 3)) % inbits] << 8)|
111				  (in[((inbits) - (msbit >> 3)) % inbits]))
112				 >> ((msbit & 7) + 1)) & 0xff;
113
114		/* do the addition */
115		byte += out[i % outbits];
116		out[i % outbits] = byte & 0xff;
117
118		/* keep around the carry bit, if any */
119		byte >>= 8;
120
121	}
122
123	/* if there's a carry bit left over, add it back in */
124	if (byte) {
125		for (i = outbits - 1; i >= 0; i--) {
126			/* do the addition */
127			byte += out[i];
128			out[i] = byte & 0xff;
129
130			/* keep around the carry bit, if any */
131			byte >>= 8;
132		}
133	}
134}
135
136/*
137 * This is the DK (derive_key) function as described in rfc3961, sec 5.1
138 * Taken from MIT Kerberos and modified.
139 */
140
141u32 krb5_derive_key(const struct gss_krb5_enctype *gk5e,
142		    const struct xdr_netobj *inkey,
143		    struct xdr_netobj *outkey,
144		    const struct xdr_netobj *in_constant,
145		    gfp_t gfp_mask)
146{
147	size_t blocksize, keybytes, keylength, n;
148	unsigned char *inblockdata, *outblockdata, *rawkey;
149	struct xdr_netobj inblock, outblock;
150	struct crypto_sync_skcipher *cipher;
151	u32 ret = EINVAL;
152
153	blocksize = gk5e->blocksize;
154	keybytes = gk5e->keybytes;
155	keylength = gk5e->keylength;
156
157	if ((inkey->len != keylength) || (outkey->len != keylength))
158		goto err_return;
159
160	cipher = crypto_alloc_sync_skcipher(gk5e->encrypt_name, 0, 0);
 
161	if (IS_ERR(cipher))
162		goto err_return;
163	if (crypto_sync_skcipher_setkey(cipher, inkey->data, inkey->len))
164		goto err_return;
165
166	/* allocate and set up buffers */
167
168	ret = ENOMEM;
169	inblockdata = kmalloc(blocksize, gfp_mask);
170	if (inblockdata == NULL)
171		goto err_free_cipher;
172
173	outblockdata = kmalloc(blocksize, gfp_mask);
174	if (outblockdata == NULL)
175		goto err_free_in;
176
177	rawkey = kmalloc(keybytes, gfp_mask);
178	if (rawkey == NULL)
179		goto err_free_out;
180
181	inblock.data = (char *) inblockdata;
182	inblock.len = blocksize;
183
184	outblock.data = (char *) outblockdata;
185	outblock.len = blocksize;
186
187	/* initialize the input block */
188
189	if (in_constant->len == inblock.len) {
190		memcpy(inblock.data, in_constant->data, inblock.len);
191	} else {
192		krb5_nfold(in_constant->len * 8, in_constant->data,
193			   inblock.len * 8, inblock.data);
194	}
195
196	/* loop encrypting the blocks until enough key bytes are generated */
197
198	n = 0;
199	while (n < keybytes) {
200		(*(gk5e->encrypt))(cipher, NULL, inblock.data,
201				   outblock.data, inblock.len);
202
203		if ((keybytes - n) <= outblock.len) {
204			memcpy(rawkey + n, outblock.data, (keybytes - n));
205			break;
206		}
207
208		memcpy(rawkey + n, outblock.data, outblock.len);
209		memcpy(inblock.data, outblock.data, outblock.len);
210		n += outblock.len;
211	}
212
213	/* postprocess the key */
214
215	inblock.data = (char *) rawkey;
216	inblock.len = keybytes;
217
218	BUG_ON(gk5e->mk_key == NULL);
219	ret = (*(gk5e->mk_key))(gk5e, &inblock, outkey);
220	if (ret) {
221		dprintk("%s: got %d from mk_key function for '%s'\n",
222			__func__, ret, gk5e->encrypt_name);
223		goto err_free_raw;
224	}
225
226	/* clean memory, free resources and exit */
227
228	ret = 0;
229
230err_free_raw:
231	kzfree(rawkey);
 
232err_free_out:
233	kzfree(outblockdata);
 
234err_free_in:
235	kzfree(inblockdata);
 
236err_free_cipher:
237	crypto_free_sync_skcipher(cipher);
238err_return:
239	return ret;
240}
241
242#define smask(step) ((1<<step)-1)
243#define pstep(x, step) (((x)&smask(step))^(((x)>>step)&smask(step)))
244#define parity_char(x) pstep(pstep(pstep((x), 4), 2), 1)
245
246static void mit_des_fixup_key_parity(u8 key[8])
247{
248	int i;
249	for (i = 0; i < 8; i++) {
250		key[i] &= 0xfe;
251		key[i] |= 1^parity_char(key[i]);
252	}
253}
254
255/*
256 * This is the des3 key derivation postprocess function
257 */
258u32 gss_krb5_des3_make_key(const struct gss_krb5_enctype *gk5e,
259			   struct xdr_netobj *randombits,
260			   struct xdr_netobj *key)
261{
262	int i;
263	u32 ret = EINVAL;
264
265	if (key->len != 24) {
266		dprintk("%s: key->len is %d\n", __func__, key->len);
267		goto err_out;
268	}
269	if (randombits->len != 21) {
270		dprintk("%s: randombits->len is %d\n",
271			__func__, randombits->len);
272		goto err_out;
273	}
274
275	/* take the seven bytes, move them around into the top 7 bits of the
276	   8 key bytes, then compute the parity bits.  Do this three times. */
277
278	for (i = 0; i < 3; i++) {
279		memcpy(key->data + i*8, randombits->data + i*7, 7);
280		key->data[i*8+7] = (((key->data[i*8]&1)<<1) |
281				    ((key->data[i*8+1]&1)<<2) |
282				    ((key->data[i*8+2]&1)<<3) |
283				    ((key->data[i*8+3]&1)<<4) |
284				    ((key->data[i*8+4]&1)<<5) |
285				    ((key->data[i*8+5]&1)<<6) |
286				    ((key->data[i*8+6]&1)<<7));
287
288		mit_des_fixup_key_parity(key->data + i*8);
289	}
290	ret = 0;
291err_out:
292	return ret;
293}
294
295/*
296 * This is the aes key derivation postprocess function
297 */
298u32 gss_krb5_aes_make_key(const struct gss_krb5_enctype *gk5e,
299			  struct xdr_netobj *randombits,
300			  struct xdr_netobj *key)
301{
302	u32 ret = EINVAL;
303
304	if (key->len != 16 && key->len != 32) {
305		dprintk("%s: key->len is %d\n", __func__, key->len);
306		goto err_out;
307	}
308	if (randombits->len != 16 && randombits->len != 32) {
309		dprintk("%s: randombits->len is %d\n",
310			__func__, randombits->len);
311		goto err_out;
312	}
313	if (randombits->len != key->len) {
314		dprintk("%s: randombits->len is %d, key->len is %d\n",
315			__func__, randombits->len, key->len);
316		goto err_out;
317	}
318	memcpy(key->data, randombits->data, key->len);
319	ret = 0;
320err_out:
321	return ret;
322}