1/*
2 * Copyright (c) 1997-2004 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "rsh_locl.h"
35RCSID("$Id$");
36
37#if defined(KRB5)
38
39#ifdef KRB5
40int key_usage = 1026;
41
42void *ivec_in[2];
43void *ivec_out[2];
44
45void
46init_ivecs(int client, int have_errsock)
47{
48    size_t blocksize;
49
50    krb5_crypto_getblocksize(context, crypto, &blocksize);
51
52    ivec_in[0] = malloc(blocksize);
53    memset(ivec_in[0], client, blocksize);
54
55    if(have_errsock) {
56	ivec_in[1] = malloc(blocksize);
57	memset(ivec_in[1], 2 | client, blocksize);
58    } else
59	ivec_in[1] = ivec_in[0];
60
61    ivec_out[0] = malloc(blocksize);
62    memset(ivec_out[0], !client, blocksize);
63
64    if(have_errsock) {
65	ivec_out[1] = malloc(blocksize);
66	memset(ivec_out[1], 2 | !client, blocksize);
67    } else
68	ivec_out[1] = ivec_out[0];
69}
70#endif
71
72
73ssize_t
74do_read (int fd, void *buf, size_t sz, void *ivec)
75{
76    if (do_encrypt) {
77#ifdef KRB5
78        if(auth_method == AUTH_KRB5) {
79	    krb5_error_code ret;
80	    uint32_t len, outer_len;
81	    int status;
82	    krb5_data data;
83	    void *edata;
84
85	    ret = krb5_net_read (context, &fd, &len, 4);
86	    if (ret <= 0)
87		return ret;
88	    len = ntohl(len);
89	    if (len > sz)
90		abort ();
91	    /* ivec will be non null for protocol version 2 */
92	    if(ivec != NULL)
93		outer_len = krb5_get_wrapped_length (context, crypto, len + 4);
94	    else
95		outer_len = krb5_get_wrapped_length (context, crypto, len);
96	    edata = malloc (outer_len);
97	    if (edata == NULL)
98		errx (1, "malloc: cannot allocate %u bytes", outer_len);
99	    ret = krb5_net_read (context, &fd, edata, outer_len);
100	    if (ret <= 0) {
101		free(edata);
102		return ret;
103	    }
104
105	    status = krb5_decrypt_ivec(context, crypto, key_usage,
106				       edata, outer_len, &data, ivec);
107	    free (edata);
108
109	    if (status)
110		krb5_err (context, 1, status, "decrypting data");
111	    if(ivec != NULL) {
112		unsigned long l;
113		if(data.length < len + 4)
114		    errx (1, "data received is too short");
115		_krb5_get_int(data.data, &l, 4);
116		if(l != len)
117		    errx (1, "inconsistency in received data");
118		memcpy (buf, (unsigned char *)data.data+4, len);
119	    } else
120		memcpy (buf, data.data, len);
121	    krb5_data_free (&data);
122	    return len;
123	} else
124#endif /* KRB5 */
125	    abort ();
126    } else
127	return read (fd, buf, sz);
128}
129
130ssize_t
131do_write (int fd, void *buf, size_t sz, void *ivec)
132{
133    if (do_encrypt) {
134#ifdef KRB5
135	if(auth_method == AUTH_KRB5) {
136	    krb5_error_code status;
137	    krb5_data data;
138	    unsigned char len[4];
139	    int ret;
140
141	    _krb5_put_int(len, sz, 4);
142	    if(ivec != NULL) {
143		unsigned char *tmp = malloc(sz + 4);
144		if(tmp == NULL)
145		    err(1, "malloc");
146		_krb5_put_int(tmp, sz, 4);
147		memcpy(tmp + 4, buf, sz);
148		status = krb5_encrypt_ivec(context, crypto, key_usage,
149					   tmp, sz + 4, &data, ivec);
150		free(tmp);
151	    } else
152		status = krb5_encrypt_ivec(context, crypto, key_usage,
153					   buf, sz, &data, ivec);
154
155	    if (status)
156		krb5_err(context, 1, status, "encrypting data");
157
158	    ret = krb5_net_write (context, &fd, len, 4);
159	    if (ret != 4)
160		return ret;
161	    ret = krb5_net_write (context, &fd, data.data, data.length);
162	    if (ret != data.length)
163		return ret;
164	    free (data.data);
165	    return sz;
166	} else
167#endif /* KRB5 */
168	    abort();
169    } else
170	return write (fd, buf, sz);
171}
172#endif /* KRB5 */
173