1 /*
2  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 #pragma ident	"%Z%%M%	%I%	%E% SMI"
7 
8 /*
9  * Copyright 2000 by the Massachusetts Institute of Technology.
10  * All Rights Reserved.
11  *
12  * Export of this software from the United States of America may
13  *   require a specific license from the United States Government.
14  *   It is the responsibility of any person or organization contemplating
15  *   export to obtain such a license before exporting.
16  *
17  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
18  * distribute this software and its documentation for any purpose and
19  * without fee is hereby granted, provided that the above copyright
20  * notice appear in all copies and that both that copyright notice and
21  * this permission notice appear in supporting documentation, and that
22  * the name of M.I.T. not be used in advertising or publicity pertaining
23  * to distribution of the software without specific, written prior
24  * permission.  Furthermore if you modify this software you must label
25  * your software as modified software and not distribute it in such a
26  * fashion that it might be confused with the original M.I.T. software.
27  * M.I.T. makes no representations about the suitability of
28  * this software for any purpose.  It is provided "as is" without express
29  * or implied warranty.
30  *
31  */
32 /*
33  * Copyright 1993 by OpenVision Technologies, Inc.
34  *
35  * Permission to use, copy, modify, distribute, and sell this software
36  * and its documentation for any purpose is hereby granted without fee,
37  * provided that the above copyright notice appears in all copies and
38  * that both that copyright notice and this permission notice appear in
39  * supporting documentation, and that the name of OpenVision not be used
40  * in advertising or publicity pertaining to distribution of the software
41  * without specific, written prior permission. OpenVision makes no
42  * representations about the suitability of this software for any
43  * purpose.  It is provided "as is" without express or implied warranty.
44  *
45  * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
46  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
47  * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
48  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
49  * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
50  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
51  * PERFORMANCE OF THIS SOFTWARE.
52  */
53 
54 /*
55  * Copyright (C) 1998 by the FundsXpress, INC.
56  *
57  * All rights reserved.
58  *
59  * Export of this software from the United States of America may require
60  * a specific license from the United States Government.  It is the
61  * responsibility of any person or organization contemplating export to
62  * obtain such a license before exporting.
63  *
64  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
65  * distribute this software and its documentation for any purpose and
66  * without fee is hereby granted, provided that the above copyright
67  * notice appear in all copies and that both that copyright notice and
68  * this permission notice appear in supporting documentation, and that
69  * the name of FundsXpress. not be used in advertising or publicity pertaining
70  * to distribution of the software without specific, written prior
71  * permission.  FundsXpress makes no representations about the suitability of
72  * this software for any purpose.  It is provided "as is" without express
73  * or implied warranty.
74  *
75  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
76  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
77  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
78  */
79 
80 #include "gssapiP_krb5.h"
81 
82 size_t KRB5_CALLCONV krb5_encrypt_size(size_t, krb5_enctype);
83 
84  /* SUNW15resync - XXX find new home for this func */
85 #ifdef _KERNEL
86 size_t KRB5_CALLCONV
krb5_encrypt_size(size_t length,krb5_enctype crypto)87 krb5_encrypt_size(size_t length, krb5_enctype crypto)
88 {
89     size_t ret;
90 
91     if (krb5_c_encrypt_length(/* XXX */ 0, crypto, length, &ret))
92 	/*LINTED*/
93         return(-1); /* XXX */
94 
95     return(ret);
96 }
97 #endif
98 
99 /* V2 interface */
100 OM_uint32
krb5_gss_wrap_size_limit(minor_status,context_handle,conf_req_flag,qop_req,req_output_size,max_input_size)101 krb5_gss_wrap_size_limit(minor_status, context_handle, conf_req_flag,
102 			 qop_req, req_output_size, max_input_size)
103     OM_uint32		*minor_status;
104     gss_ctx_id_t	context_handle;
105     int			conf_req_flag;
106     gss_qop_t		qop_req;
107     OM_uint32		req_output_size;
108     OM_uint32		*max_input_size;
109 {
110     krb5_gss_ctx_id_rec	*ctx;
111     OM_uint32		data_size, conflen;
112     OM_uint32		ohlen;
113     int			overhead;
114 
115     /* Solaris Kerb - check to make sure we aren't writing to a NULL pointer */
116     if (!max_input_size)
117  	return(GSS_S_CALL_INACCESSIBLE_WRITE);
118 
119     /* only default qop is allowed */
120     /*
121      * SUNW15resync
122      * mit 1.2-6: if (qop_req != GSS_C_QOP_DEFAULT) {
123      * Go with Solaris version here, though not sure which is
124      * correct and RFC 2743 does not make it clear.
125      */
126     if ((qop_req & GSS_KRB5_CONF_C_QOP_MASK) != GSS_C_QOP_DEFAULT) {
127 	*minor_status = (OM_uint32) G_UNKNOWN_QOP;
128 	/* SUNW15resync - RFC 2743 is clear here but
129           this is still GSS_S_FAILURE in MIT */
130 	return(GSS_S_BAD_QOP);
131     }
132 
133     /* validate the context handle */
134     if (! kg_validate_ctx_id(context_handle)) {
135 	*minor_status = (OM_uint32) G_VALIDATE_FAILED;
136 	return(GSS_S_NO_CONTEXT);
137     }
138 
139     ctx = (krb5_gss_ctx_id_rec *) context_handle;
140     if (! ctx->established) {
141 	*minor_status = KG_CTX_INCOMPLETE;
142 	return(GSS_S_NO_CONTEXT);
143     }
144 
145     if (ctx->proto == 1) {
146 	/* No pseudo-ASN.1 wrapper overhead, so no sequence length and
147 	   OID.  */
148 	OM_uint32 sz = req_output_size;
149 	/* Token header: 16 octets.  */
150 	if (conf_req_flag) {
151 	    while (sz > 0 && krb5_encrypt_size(sz, ctx->enc->enctype) + 16 > req_output_size)
152 		sz--;
153 	    /* Allow for encrypted copy of header.  */
154 	    if (sz > 16)
155 		sz -= 16;
156 	    else
157 		sz = 0;
158 #ifdef CFX_EXERCISE
159 	    /* Allow for EC padding.  In the MIT implementation, only
160 	       added while testing.  */
161 	    if (sz > 65535)
162 		sz -= 65535;
163 	    else
164 		sz = 0;
165 #endif
166 	} else {
167 	    /* Allow for token header and checksum.  */
168 	    if (sz < 16 + ctx->cksum_size)
169 		sz = 0;
170 	    else
171 		sz -= (16 + ctx->cksum_size);
172 	}
173 
174 	*max_input_size = sz;
175 	*minor_status = 0;
176 	return GSS_S_COMPLETE;
177     }
178 
179     /* Calculate the token size and subtract that from the output size */
180     overhead = 7 + ctx->mech_used->length;
181     data_size = req_output_size;
182     conflen = kg_confounder_size(ctx->k5_context, ctx->enc);
183     data_size = (conflen + data_size + 8) & (~(OM_uint32)7);
184     ohlen = g_token_size(ctx->mech_used,
185 			 (unsigned int) (data_size + ctx->cksum_size + 14))
186       - req_output_size;
187 
188     if (ohlen+overhead < req_output_size)
189       /*
190        * Cannot have trailer length that will cause us to pad over our
191        * length.
192        */
193       *max_input_size = (req_output_size - ohlen - overhead) & (~(OM_uint32)7);
194     else
195       *max_input_size = 0;
196 
197     *minor_status = 0;
198     return(GSS_S_COMPLETE);
199 }
200