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
_gsskrb5_pseudo_random(OM_uint32 * minor_status,gss_ctx_id_t context_handle,int prf_key,const gss_buffer_t prf_in,ssize_t desired_output_len,gss_buffer_t prf_out)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