1/*	$NetBSD: prf.c,v 1.2 2017/01/28 21:31:46 christos Exp $	*/
2
3/*
4 * Copyright (c) 2007 Kungliga Tekniska H��gskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include "gsskrb5_locl.h"
37
38OM_uint32 GSSAPI_CALLCONV
39_gsskrb5_pseudo_random(OM_uint32 *minor_status,
40		       gss_ctx_id_t context_handle,
41		       int prf_key,
42		       const gss_buffer_t prf_in,
43		       ssize_t desired_output_len,
44		       gss_buffer_t prf_out)
45{
46    gsskrb5_ctx ctx = (gsskrb5_ctx)context_handle;
47    krb5_context context;
48    krb5_error_code ret;
49    krb5_crypto crypto;
50    krb5_data input, output;
51    uint32_t num;
52    OM_uint32 junk;
53    unsigned char *p;
54    krb5_keyblock *key = NULL;
55    size_t dol;
56
57    if (ctx == NULL) {
58	*minor_status = 0;
59	return GSS_S_NO_CONTEXT;
60    }
61
62    if (desired_output_len <= 0 || prf_in->length + 4 < prf_in->length) {
63	*minor_status = 0;
64	return GSS_S_FAILURE;
65    }
66    dol = desired_output_len;
67
68    GSSAPI_KRB5_INIT (&context);
69
70    switch(prf_key) {
71    case GSS_C_PRF_KEY_FULL:
72	_gsskrb5i_get_acceptor_subkey(ctx, context, &key);
73	break;
74    case GSS_C_PRF_KEY_PARTIAL:
75	_gsskrb5i_get_initiator_subkey(ctx, context, &key);
76	break;
77    default:
78	_gsskrb5_set_status(EINVAL, "unknown kerberos prf_key");
79	*minor_status = EINVAL;
80	return GSS_S_FAILURE;
81    }
82
83    if (key == NULL) {
84	_gsskrb5_set_status(EINVAL, "no prf_key found");
85	*minor_status = EINVAL;
86	return GSS_S_FAILURE;
87    }
88
89    ret = krb5_crypto_init(context, key, 0, &crypto);
90    krb5_free_keyblock (context, key);
91    if (ret) {
92	*minor_status = ret;
93	return GSS_S_FAILURE;
94    }
95
96    prf_out->value = malloc(dol);
97    if (prf_out->value == NULL) {
98	_gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
99	*minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
100	krb5_crypto_destroy(context, crypto);
101	return GSS_S_FAILURE;
102    }
103    prf_out->length = dol;
104
105    HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
106
107    input.length = prf_in->length + 4;
108    input.data = malloc(prf_in->length + 4);
109    if (input.data == NULL) {
110	_gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
111	*minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
112	gss_release_buffer(&junk, prf_out);
113	krb5_crypto_destroy(context, crypto);
114	HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
115	return GSS_S_FAILURE;
116    }
117    memcpy(((uint8_t *)input.data) + 4, prf_in->value, prf_in->length);
118
119    num = 0;
120    p = prf_out->value;
121    while(dol > 0) {
122	size_t tsize;
123
124	_gsskrb5_encode_be_om_uint32(num, input.data);
125
126	ret = krb5_crypto_prf(context, crypto, &input, &output);
127	if (ret) {
128	    *minor_status = ret;
129	    free(input.data);
130	    gss_release_buffer(&junk, prf_out);
131	    krb5_crypto_destroy(context, crypto);
132	    HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
133	    return GSS_S_FAILURE;
134	}
135
136	tsize = min(dol, output.length);
137	memcpy(p, output.data, tsize);
138	p += tsize;
139	dol -= tsize;
140	krb5_data_free(&output);
141	num++;
142    }
143    free(input.data);
144
145    krb5_crypto_destroy(context, crypto);
146
147    HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
148
149    return GSS_S_COMPLETE;
150}
151