1 /*
2 * linux/net/sunrpc/gss_krb5_seqnum.c
3 *
4 * Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/util_seqnum.c
5 *
6 * Copyright (c) 2000 The Regents of the University of Michigan.
7 * All rights reserved.
8 *
9 * Andy Adamson <andros@umich.edu>
10 */
11
12 /*
13 * Copyright 1993 by OpenVision Technologies, Inc.
14 *
15 * Permission to use, copy, modify, distribute, and sell this software
16 * and its documentation for any purpose is hereby granted without fee,
17 * provided that the above copyright notice appears in all copies and
18 * that both that copyright notice and this permission notice appear in
19 * supporting documentation, and that the name of OpenVision not be used
20 * in advertising or publicity pertaining to distribution of the software
21 * without specific, written prior permission. OpenVision makes no
22 * representations about the suitability of this software for any
23 * purpose. It is provided "as is" without express or implied warranty.
24 *
25 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
26 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
27 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
28 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
29 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
30 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
31 * PERFORMANCE OF THIS SOFTWARE.
32 */
33
34 #include <crypto/skcipher.h>
35 #include <linux/types.h>
36 #include <linux/sunrpc/gss_krb5.h>
37
38 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
39 # define RPCDBG_FACILITY RPCDBG_AUTH
40 #endif
41
42 static s32
krb5_make_rc4_seq_num(struct krb5_ctx * kctx,int direction,s32 seqnum,unsigned char * cksum,unsigned char * buf)43 krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
44 unsigned char *cksum, unsigned char *buf)
45 {
46 struct crypto_skcipher *cipher;
47 unsigned char *plain;
48 s32 code;
49
50 dprintk("RPC: %s:\n", __func__);
51 cipher = crypto_alloc_skcipher(kctx->gk5e->encrypt_name, 0,
52 CRYPTO_ALG_ASYNC);
53 if (IS_ERR(cipher))
54 return PTR_ERR(cipher);
55
56 plain = kmalloc(8, GFP_NOFS);
57 if (!plain)
58 return -ENOMEM;
59
60 plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
61 plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
62 plain[2] = (unsigned char) ((seqnum >> 8) & 0xff);
63 plain[3] = (unsigned char) ((seqnum >> 0) & 0xff);
64 plain[4] = direction;
65 plain[5] = direction;
66 plain[6] = direction;
67 plain[7] = direction;
68
69 code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
70 if (code)
71 goto out;
72
73 code = krb5_encrypt(cipher, cksum, plain, buf, 8);
74 out:
75 crypto_free_skcipher(cipher);
76 kfree(plain);
77 return code;
78 }
79 s32
krb5_make_seq_num(struct krb5_ctx * kctx,struct crypto_skcipher * key,int direction,u32 seqnum,unsigned char * cksum,unsigned char * buf)80 krb5_make_seq_num(struct krb5_ctx *kctx,
81 struct crypto_skcipher *key,
82 int direction,
83 u32 seqnum,
84 unsigned char *cksum, unsigned char *buf)
85 {
86 unsigned char *plain;
87 s32 code;
88
89 if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
90 return krb5_make_rc4_seq_num(kctx, direction, seqnum,
91 cksum, buf);
92
93 plain = kmalloc(8, GFP_NOFS);
94 if (!plain)
95 return -ENOMEM;
96
97 plain[0] = (unsigned char) (seqnum & 0xff);
98 plain[1] = (unsigned char) ((seqnum >> 8) & 0xff);
99 plain[2] = (unsigned char) ((seqnum >> 16) & 0xff);
100 plain[3] = (unsigned char) ((seqnum >> 24) & 0xff);
101
102 plain[4] = direction;
103 plain[5] = direction;
104 plain[6] = direction;
105 plain[7] = direction;
106
107 code = krb5_encrypt(key, cksum, plain, buf, 8);
108 kfree(plain);
109 return code;
110 }
111
112 static s32
krb5_get_rc4_seq_num(struct krb5_ctx * kctx,unsigned char * cksum,unsigned char * buf,int * direction,s32 * seqnum)113 krb5_get_rc4_seq_num(struct krb5_ctx *kctx, unsigned char *cksum,
114 unsigned char *buf, int *direction, s32 *seqnum)
115 {
116 struct crypto_skcipher *cipher;
117 unsigned char *plain;
118 s32 code;
119
120 dprintk("RPC: %s:\n", __func__);
121 cipher = crypto_alloc_skcipher(kctx->gk5e->encrypt_name, 0,
122 CRYPTO_ALG_ASYNC);
123 if (IS_ERR(cipher))
124 return PTR_ERR(cipher);
125
126 code = krb5_rc4_setup_seq_key(kctx, cipher, cksum);
127 if (code)
128 goto out;
129
130 plain = kmalloc(8, GFP_NOFS);
131 if (!plain) {
132 code = -ENOMEM;
133 goto out;
134 }
135
136 code = krb5_decrypt(cipher, cksum, buf, plain, 8);
137 if (code)
138 goto out_plain;
139
140 if ((plain[4] != plain[5]) || (plain[4] != plain[6])
141 || (plain[4] != plain[7])) {
142 code = (s32)KG_BAD_SEQ;
143 goto out_plain;
144 }
145
146 *direction = plain[4];
147
148 *seqnum = ((plain[0] << 24) | (plain[1] << 16) |
149 (plain[2] << 8) | (plain[3]));
150 out_plain:
151 kfree(plain);
152 out:
153 crypto_free_skcipher(cipher);
154 return code;
155 }
156
157 s32
krb5_get_seq_num(struct krb5_ctx * kctx,unsigned char * cksum,unsigned char * buf,int * direction,u32 * seqnum)158 krb5_get_seq_num(struct krb5_ctx *kctx,
159 unsigned char *cksum,
160 unsigned char *buf,
161 int *direction, u32 *seqnum)
162 {
163 s32 code;
164 struct crypto_skcipher *key = kctx->seq;
165 unsigned char *plain;
166
167 dprintk("RPC: krb5_get_seq_num:\n");
168
169 if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC)
170 return krb5_get_rc4_seq_num(kctx, cksum, buf,
171 direction, seqnum);
172 plain = kmalloc(8, GFP_NOFS);
173 if (!plain)
174 return -ENOMEM;
175
176 if ((code = krb5_decrypt(key, cksum, buf, plain, 8)))
177 goto out;
178
179 if ((plain[4] != plain[5]) || (plain[4] != plain[6]) ||
180 (plain[4] != plain[7])) {
181 code = (s32)KG_BAD_SEQ;
182 goto out;
183 }
184
185 *direction = plain[4];
186
187 *seqnum = ((plain[0]) |
188 (plain[1] << 8) | (plain[2] << 16) | (plain[3] << 24));
189
190 out:
191 kfree(plain);
192 return code;
193 }
194