xref: /freebsd/crypto/heimdal/lib/gssapi/krb5/prf.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
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 "krb5/gsskrb5_locl.h"
35 
36 RCSID("$Id: prf.c 21129 2007-06-18 20:28:44Z lha $");
37 
38 OM_uint32
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     unsigned char *p;
53     krb5_keyblock *key = NULL;
54 
55     if (ctx == NULL) {
56 	*minor_status = 0;
57 	return GSS_S_NO_CONTEXT;
58     }
59 
60     if (desired_output_len <= 0) {
61 	*minor_status = 0;
62 	return GSS_S_FAILURE;
63     }
64 
65     GSSAPI_KRB5_INIT (&context);
66 
67     switch(prf_key) {
68     case GSS_C_PRF_KEY_FULL:
69 	_gsskrb5i_get_acceptor_subkey(ctx, context, &key);
70 	break;
71     case GSS_C_PRF_KEY_PARTIAL:
72 	_gsskrb5i_get_initiator_subkey(ctx, context, &key);
73 	break;
74     default:
75 	_gsskrb5_set_status("unknown kerberos prf_key");
76 	*minor_status = 0;
77 	return GSS_S_FAILURE;
78     }
79 
80     if (key == NULL) {
81 	_gsskrb5_set_status("no prf_key found");
82 	*minor_status = 0;
83 	return GSS_S_FAILURE;
84     }
85 
86     ret = krb5_crypto_init(context, key, 0, &crypto);
87     krb5_free_keyblock (context, key);
88     if (ret) {
89 	*minor_status = ret;
90 	return GSS_S_FAILURE;
91     }
92 
93     prf_out->value = malloc(desired_output_len);
94     if (prf_out->value == NULL) {
95 	_gsskrb5_set_status("Out of memory");
96 	*minor_status = GSS_KRB5_S_KG_INPUT_TOO_LONG;
97 	krb5_crypto_destroy(context, crypto);
98 	return GSS_S_FAILURE;
99     }
100     prf_out->length = desired_output_len;
101 
102     HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex);
103 
104     input.length = prf_in->length + 4;
105     input.data = malloc(prf_in->length + 4);
106     if (input.data == NULL) {
107 	OM_uint32 junk;
108 	_gsskrb5_set_status("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(((unsigned char *)input.data) + 4, prf_in->value, prf_in->length);
116 
117     num = 0;
118     p = prf_out->value;
119     while(desired_output_len > 0) {
120 	_gsskrb5_encode_om_uint32(num, input.data);
121 	ret = krb5_crypto_prf(context, crypto, &input, &output);
122 	if (ret) {
123 	    OM_uint32 junk;
124 	    *minor_status = ret;
125 	    free(input.data);
126 	    gss_release_buffer(&junk, prf_out);
127 	    krb5_crypto_destroy(context, crypto);
128 	    HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
129 	    return GSS_S_FAILURE;
130 	}
131 	memcpy(p, output.data, min(desired_output_len, output.length));
132 	p += output.length;
133 	desired_output_len -= output.length;
134 	krb5_data_free(&output);
135 	num++;
136     }
137 
138     krb5_crypto_destroy(context, crypto);
139 
140     HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex);
141 
142     return GSS_S_COMPLETE;
143 }
144