xref: /freebsd/crypto/heimdal/lib/gssapi/krb5/prf.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright (c) 2007 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 "gsskrb5_locl.h"
35 
36 OM_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