1 /*
2  * lib/krb5/krb/ser_cksum.c
3  *
4  * Copyright 1995 by the Massachusetts Institute of Technology.
5  * All Rights Reserved.
6  *
7  * Export of this software from the United States of America may
8  *   require a specific license from the United States Government.
9  *   It is the responsibility of any person or organization contemplating
10  *   export to obtain such a license before exporting.
11  *
12  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
13  * distribute this software and its documentation for any purpose and
14  * without fee is hereby granted, provided that the above copyright
15  * notice appear in all copies and that both that copyright notice and
16  * this permission notice appear in supporting documentation, and that
17  * the name of M.I.T. not be used in advertising or publicity pertaining
18  * to distribution of the software without specific, written prior
19  * permission.  Furthermore if you modify this software you must label
20  * your software as modified software and not distribute it in such a
21  * fashion that it might be confused with the original M.I.T. software.
22  * M.I.T. makes no representations about the suitability of
23  * this software for any purpose.  It is provided "as is" without express
24  * or implied warranty.
25  *
26  */
27 
28 /*
29  * ser_cksum.c - Serialize a krb5_checksum structure.
30  */
31 #include "k5-int.h"
32 #include "int-proto.h"
33 
34 /*
35  * Routines to deal with externalizing the krb5_checksum:
36  *	krb5_checksum_esize();
37  *	krb5_checksum_externalize();
38  *	krb5_checksum_internalize();
39  */
40 static krb5_error_code krb5_checksum_esize
41 	(krb5_context, krb5_pointer, size_t *);
42 static krb5_error_code krb5_checksum_externalize
43 	(krb5_context, krb5_pointer, krb5_octet **, size_t *);
44 static krb5_error_code krb5_checksum_internalize
45 	(krb5_context,krb5_pointer *, krb5_octet **, size_t *);
46 
47 /* Local data */
48 static const krb5_ser_entry krb5_checksum_ser_entry = {
49     KV5M_CHECKSUM,			/* Type			*/
50     krb5_checksum_esize,		/* Sizer routine	*/
51     krb5_checksum_externalize,		/* Externalize routine	*/
52     krb5_checksum_internalize		/* Internalize routine	*/
53 };
54 
55 /*
56  * krb5_checksum_esize()	- Determine the size required to externalize
57  *				  the krb5_checksum.
58  */
59 /*ARGSUSED*/
60 static krb5_error_code
krb5_checksum_esize(krb5_context kcontext,krb5_pointer arg,size_t * sizep)61 krb5_checksum_esize(krb5_context kcontext, krb5_pointer arg, size_t *sizep)
62 {
63     krb5_error_code	kret;
64     krb5_checksum	*checksum;
65 
66     /*
67      * krb5_checksum requires:
68      *	krb5_int32		for KV5M_CHECKSUM
69      *	krb5_int32		for checksum_type
70      *	krb5_int32		for length
71      *	krb5_int32		for KV5M_CHECKSUM
72      *	checksum->length	for contents
73      */
74     kret = EINVAL;
75     /* Solaris Kerberos */
76     checksum = (krb5_checksum *) arg;
77     if (checksum) {
78 	*sizep += (sizeof(krb5_int32) +
79 		   sizeof(krb5_int32) +
80 		   sizeof(krb5_int32) +
81 		   sizeof(krb5_int32) +
82 		   (size_t) checksum->length);
83 	kret = 0;
84     }
85     return(kret);
86 }
87 
88 /*
89  * krb5_checksum_externalize()	- Externalize the krb5_checksum.
90  */
91 static krb5_error_code
krb5_checksum_externalize(krb5_context kcontext,krb5_pointer arg,krb5_octet ** buffer,size_t * lenremain)92 krb5_checksum_externalize(krb5_context kcontext, krb5_pointer arg, krb5_octet **buffer, size_t *lenremain)
93 {
94     krb5_error_code	kret;
95     krb5_checksum	*checksum;
96     size_t		required;
97     krb5_octet		*bp;
98     size_t		remain;
99 
100     required = 0;
101     bp = *buffer;
102     remain = *lenremain;
103     kret = EINVAL;
104     /* Solaris Kerberos */
105     checksum = (krb5_checksum *) arg;
106     if (checksum) {
107 	kret = ENOMEM;
108 	if (!krb5_checksum_esize(kcontext, arg, &required) &&
109 	    (required <= remain)) {
110 	    /* Our identifier */
111 	    (void) krb5_ser_pack_int32(KV5M_CHECKSUM, &bp, &remain);
112 
113 	    /* Our checksum_type */
114 	    (void) krb5_ser_pack_int32((krb5_int32) checksum->checksum_type,
115 				       &bp, &remain);
116 
117 	    /* Our length */
118 	    (void) krb5_ser_pack_int32((krb5_int32) checksum->length,
119 				       &bp, &remain);
120 
121 	    /* Our contents */
122 	    (void) krb5_ser_pack_bytes(checksum->contents,
123 				       (size_t) checksum->length,
124 				       &bp, &remain);
125 
126 	    /* Finally, our trailer */
127 	    (void) krb5_ser_pack_int32(KV5M_CHECKSUM, &bp, &remain);
128 
129 	    kret = 0;
130 	    *buffer = bp;
131 	    *lenremain = remain;
132 	}
133     }
134     return(kret);
135 }
136 
137 /*
138  * krb5_checksum_internalize()	- Internalize the krb5_checksum.
139  */
140 /*ARGSUSED*/
141 static krb5_error_code
krb5_checksum_internalize(krb5_context kcontext,krb5_pointer * argp,krb5_octet ** buffer,size_t * lenremain)142 krb5_checksum_internalize(krb5_context kcontext, krb5_pointer *argp, krb5_octet **buffer, size_t *lenremain)
143 {
144     krb5_error_code	kret;
145     krb5_checksum	*checksum;
146     krb5_int32		ibuf;
147     krb5_octet		*bp;
148     size_t		remain;
149 
150     bp = *buffer;
151     remain = *lenremain;
152     kret = EINVAL;
153     /* Read our magic number */
154     if (krb5_ser_unpack_int32(&ibuf, &bp, &remain))
155 	ibuf = 0;
156     if (ibuf == KV5M_CHECKSUM) {
157 	kret = ENOMEM;
158 
159 	/* Get a checksum */
160 	if ((remain >= (2*sizeof(krb5_int32))) &&
161 	    (checksum = (krb5_checksum *) MALLOC(sizeof(krb5_checksum)))) {
162 	    (void) memset(checksum, 0, sizeof(krb5_checksum));
163 
164 	    /* Get the checksum_type */
165 	    (void) krb5_ser_unpack_int32(&ibuf, &bp, &remain);
166 	    checksum->checksum_type = (krb5_cksumtype) ibuf;
167 
168 	    /* Get the length */
169 	    (void) krb5_ser_unpack_int32(&ibuf, &bp, &remain);
170 	    checksum->length = (int) ibuf;
171 
172 	    /* Get the string */
173 	    /* Solaris Kerberos */
174 	    if (ibuf)
175 		checksum->contents = (krb5_octet *)
176 		 			 MALLOC((size_t) (ibuf));
177 
178 	    if (!ibuf ||
179 		((checksum->contents) &&
180 		 !(kret = krb5_ser_unpack_bytes(checksum->contents,
181 						(size_t) ibuf,
182 						&bp, &remain)))) {
183 
184 		/* Get the trailer */
185 		kret = krb5_ser_unpack_int32(&ibuf, &bp, &remain);
186 		if (!kret && (ibuf == KV5M_CHECKSUM)) {
187 		    checksum->magic = KV5M_CHECKSUM;
188 		    *buffer = bp;
189 		    *lenremain = remain;
190 		    *argp = (krb5_pointer) checksum;
191 		}
192 		else
193 		    kret = EINVAL;
194 	    }
195 	    if (kret) {
196 		if (checksum->contents)
197 		    FREE(checksum->contents, checksum->length);
198 		FREE(checksum, sizeof (krb5_checksum));
199 	    }
200 	}
201     }
202     return(kret);
203 }
204 
205 /*
206  * Register the checksum serializer.
207  */
208 krb5_error_code
krb5_ser_checksum_init(krb5_context kcontext)209 krb5_ser_checksum_init(krb5_context kcontext)
210 {
211     return(krb5_register_serializer(kcontext, &krb5_checksum_ser_entry));
212 }
213