prf.c revision 259758 
1/*
2 * Copyright (c) 2007 Kungliga Tekniska H��gskolan
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 "gsskrb5_locl.h"
35
36OM_uint32 GSSAPI_CALLCONV
37_gsskrb5_pseudo_random(OM_uint32 *minor_status,
38		       gss_ctx_id_t context_handle,
39		       int prf_key,
40		       const gss_buffer_t prf_in,
41		       ssize_t desired_output_len,
42		       gss_buffer_t prf_out)
43{
44    gsskrb5_ctx ctx = (gsskrb5_ctx)context_handle;
45    krb5_context context;
46    krb5_error_code ret;
47    krb5_crypto crypto;
48    krb5_data input, output;
49    uint32_t num;
50    OM_uint32 junk;
51    unsigned char *p;
52    krb5_keyblock *key = NULL;
53    size_t dol;
54
55    if (ctx == NULL) {
56	*minor_status = 0;
57	return GSS_S_NO_CONTEXT;
58    }
59
60    if (desired_output_len <= 0 || prf_in->length + 4 < prf_in->length) {
61	*minor_status = 0;
62	return GSS_S_FAILURE;
63    }
64    dol = desired_output_len;
65
66    GSSAPI_KRB5_INIT (&context);
67
68    switch(prf_key) {
69    case GSS_C_PRF_KEY_FULL:
70	_gsskrb5i_get_acceptor_subkey(ctx, context, &key);
71	break;
72    case GSS_C_PRF_KEY_PARTIAL:
73	_gsskrb5i_get_initiator_subkey(ctx, context, &key);
74	break;
75    default:
76	_gsskrb5_set_status(EINVAL, "unknown kerberos prf_key");
77	*minor_status = EINVAL;
78	return GSS_S_FAILURE;
79    }
80
81    if (key == NULL) {
82	_gsskrb5_set_status(EINVAL, "no prf_key found");
83	*minor_status = EINVAL;
84	return GSS_S_FAILURE;
85    }
86
87    ret = krb5_crypto_init(context, key, 0, &crypto);
88    krb5_free_keyblock (context, key);
89    if (ret) {
90	*minor_status = ret;
91	return GSS_S_FAILURE;
92    }
93
94    prf_out->value = malloc(dol);
95    if (prf_out->value == NULL) {
96	_gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
97	*minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
98	krb5_crypto_destroy(context, crypto);
99	return GSS_S_FAILURE;
100    }
101    prf_out->length = dol;
102
103    HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
104
105    input.length = prf_in->length + 4;
106    input.data = malloc(prf_in->length + 4);
107    if (input.data == NULL) {
108	_gsskrb5_set_status(GSS_KRB5_S_KG_INPUT_TOO_LONG, "Out of memory");
109	*minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
110	gss_release_buffer(&junk, prf_out);
111	krb5_crypto_destroy(context, crypto);
112	HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
113	return GSS_S_FAILURE;
114    }
115    memcpy(((uint8_t *)input.data) + 4, prf_in->value, prf_in->length);
116
117    num = 0;
118    p = prf_out->value;
119    while(dol > 0) {
120	size_t tsize;
121
122	_gsskrb5_encode_be_om_uint32(num, input.data);
123
124	ret = krb5_crypto_prf(context, crypto, &input, &output);
125	if (ret) {
126	    *minor_status = ret;
127	    free(input.data);
128	    gss_release_buffer(&junk, prf_out);
129	    krb5_crypto_destroy(context, crypto);
130	    HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
131	    return GSS_S_FAILURE;
132	}
133
134	tsize = min(dol, output.length);
135	memcpy(p, output.data, tsize);
136	p += tsize;
137	dol -= tsize;
138	krb5_data_free(&output);
139	num++;
140    }
141    free(input.data);
142
143    krb5_crypto_destroy(context, crypto);
144
145    HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
146
147    return GSS_S_COMPLETE;
148}
149