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      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
     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
    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