1 #pragma ident "%Z%%M% %I% %E% SMI"
2
3 /* Coding Buffer Specifications */
4 #ifndef __ASN1BUF_H__
5 #define __ASN1BUF_H__
6
7 #include "k5-int.h"
8 #include "krbasn1.h"
9
10 typedef struct code_buffer_rep {
11 char *base, *bound, *next;
12 } asn1buf;
13
14
15 /**************** Private Procedures ****************/
16
17 int asn1buf_size
18 (const asn1buf *buf);
19 /* requires *buf has been created and not destroyed
20 effects Returns the total size
21 (in octets) of buf's octet buffer. */
22 #define asn1buf_size(buf) \
23 (((buf) == NULL || (buf)->base == NULL) \
24 ? 0 \
25 : ((buf)->bound - (buf)->base + 1))
26
27 int asn1buf_free
28 (const asn1buf *buf);
29 /* requires *buf is allocated
30 effects Returns the number of unused, allocated octets in *buf. */
31 #define asn1buf_free(buf) \
32 (((buf) == NULL || (buf)->base == NULL) \
33 ? 0 \
34 : ((buf)->bound - (buf)->next + 1))
35
36
37 asn1_error_code asn1buf_ensure_space
38 (asn1buf *buf, const unsigned int amount);
39 /* requires *buf is allocated
40 modifies *buf
41 effects If buf has less than amount octets of free space, then it is
42 expanded to have at least amount octets of free space.
43 Returns ENOMEM memory is exhausted. */
44 #define asn1buf_ensure_space(buf,amount) \
45 ((asn1buf_free(buf) < (amount)) \
46 ? (asn1buf_expand((buf), (amount)-asn1buf_free(buf))) \
47 : 0)
48
49
50 asn1_error_code asn1buf_expand
51 (asn1buf *buf, unsigned int inc);
52 /* requires *buf is allocated
53 modifies *buf
54 effects Expands *buf by allocating space for inc more octets.
55 Returns ENOMEM if memory is exhausted. */
56
57 int asn1buf_len
58 (const asn1buf *buf);
59 /* requires *buf is allocated
60 effects Returns the length of the encoding in *buf. */
61 #define asn1buf_len(buf) ((buf)->next - (buf)->base)
62
63 /****** End of private procedures *****/
64
65 /*
66 Overview
67
68 The coding buffer is an array of char (to match a krb5_data structure)
69 with 3 reference pointers:
70 1) base - The bottom of the octet array. Used for memory management
71 operations on the array (e.g. alloc, realloc, free).
72 2) next - Points to the next available octet position in the array.
73 During encoding, this is the next free position, and it
74 advances as octets are added to the array.
75 During decoding, this is the next unread position, and it
76 advances as octets are read from the array.
77 3) bound - Points to the top of the array. Used for bounds-checking.
78
79 All pointers to encoding buffers should be initalized to NULL.
80
81 Operations
82
83 asn1buf_create
84 asn1buf_wrap_data
85 asn1buf_destroy
86 asn1buf_insert_octet
87 asn1buf_insert_charstring
88 asn1buf_remove_octet
89 asn1buf_remove_charstring
90 asn1buf_unparse
91 asn1buf_hex_unparse
92 asn12krb5_buf
93 asn1buf_remains
94
95 (asn1buf_size)
96 (asn1buf_free)
97 (asn1buf_ensure_space)
98 (asn1buf_expand)
99 (asn1buf_len)
100 */
101
102 asn1_error_code asn1buf_create
103 (asn1buf **buf);
104 /* effects Creates a new encoding buffer pointed to by *buf.
105 Returns ENOMEM if the buffer can't be created. */
106
107 asn1_error_code asn1buf_wrap_data
108 (asn1buf *buf, const krb5_data *code);
109 /* requires *buf has already been allocated
110 effects Turns *buf into a "wrapper" for *code. i.e. *buf is set up
111 such that its bottom is the beginning of *code, and its top
112 is the top of *code.
113 Returns ASN1_MISSING_FIELD if code is empty. */
114
115 asn1_error_code asn1buf_imbed
116 (asn1buf *subbuf, const asn1buf *buf,
117 const unsigned int length,
118 const int indef);
119 /* requires *subbuf and *buf are allocated
120 effects *subbuf becomes a sub-buffer of *buf. *subbuf begins
121 at *buf's current position and is length octets long.
122 (Unless this would exceed the bounds of *buf -- in
123 that case, ASN1_OVERRUN is returned) *subbuf's current
124 position starts at the beginning of *subbuf. */
125
126 asn1_error_code asn1buf_sync
127 (asn1buf *buf, asn1buf *subbuf, const asn1_class Class,
128 const asn1_tagnum lasttag,
129 const unsigned int length, const int indef,
130 const int seqindef);
131 /* requires *subbuf is a sub-buffer of *buf, as created by asn1buf_imbed.
132 lasttag is the last tagnumber read.
133 effects Synchronizes *buf's current position to match that of *subbuf. */
134
135 asn1_error_code asn1buf_skiptail
136 (asn1buf *buf, const unsigned int length,
137 const int indef);
138 /* requires *buf is a subbuffer used in a decoding of a
139 constructed indefinite sequence.
140 effects skips trailing fields. */
141
142 asn1_error_code asn1buf_destroy
143 (asn1buf **buf);
144 /* effects Deallocates **buf, sets *buf to NULL. */
145
146 asn1_error_code asn1buf_insert_octet
147 (asn1buf *buf, const int o);
148 /* requires *buf is allocated
149 effects Inserts o into the buffer *buf, expanding the buffer if
150 necessary. Returns ENOMEM memory is exhausted. */
151 #if ((__GNUC__ >= 2) && !defined(ASN1BUF_OMIT_INLINE_FUNCS))
asn1buf_insert_octet(asn1buf * buf,const int o)152 extern __inline__ asn1_error_code asn1buf_insert_octet(asn1buf *buf, const int o)
153 {
154 asn1_error_code retval;
155
156 retval = asn1buf_ensure_space(buf,1U);
157 if(retval) return retval;
158 *(buf->next) = (char)o;
159 (buf->next)++;
160 return 0;
161 }
162 #endif
163
164 asn1_error_code asn1buf_insert_octetstring
165 (asn1buf *buf, const unsigned int len, const asn1_octet *s);
166 /* requires *buf is allocated
167 modifies *buf
168 effects Inserts the contents of s (an octet array of length len)
169 into the buffer *buf, expanding the buffer if necessary.
170 Returns ENOMEM if memory is exhausted. */
171
172 asn1_error_code asn1buf_insert_charstring
173 (asn1buf *buf, const unsigned int len, const char *s);
174 /* requires *buf is allocated
175 modifies *buf
176 effects Inserts the contents of s (a character array of length len)
177 into the buffer *buf, expanding the buffer if necessary.
178 Returns ENOMEM if memory is exhausted. */
179
180 asn1_error_code asn1buf_remove_octet
181 (asn1buf *buf, asn1_octet *o);
182 /* requires *buf is allocated
183 effects Returns *buf's current octet in *o and advances to
184 the next octet.
185 Returns ASN1_OVERRUN if *buf has already been exhausted. */
186 #define asn1buf_remove_octet(buf,o) \
187 (((buf)->next > (buf)->bound) \
188 ? ASN1_OVERRUN \
189 : ((*(o) = (asn1_octet)(*(((buf)->next)++))),0))
190
191 asn1_error_code asn1buf_remove_octetstring
192 (asn1buf *buf, const unsigned int len, asn1_octet **s);
193 /* requires *buf is allocated
194 effects Removes the next len octets of *buf and returns them in **s.
195 Returns ASN1_OVERRUN if there are fewer than len unread octets
196 left in *buf.
197 Returns ENOMEM if *s could not be allocated. */
198
199 asn1_error_code asn1buf_remove_charstring
200 (asn1buf *buf, const unsigned int len,
201 char **s);
202 /* requires *buf is allocated
203 effects Removes the next len octets of *buf and returns them in **s.
204 Returns ASN1_OVERRUN if there are fewer than len unread octets
205 left in *buf.
206 Returns ENOMEM if *s could not be allocated. */
207
208 asn1_error_code asn1buf_unparse
209 (const asn1buf *buf, char **s);
210 /* modifies *s
211 effects Returns a human-readable representation of *buf in *s,
212 where each octet in *buf is represented by a character in *s. */
213
214 asn1_error_code asn1buf_hex_unparse
215 (const asn1buf *buf, char **s);
216 /* modifies *s
217 effects Returns a human-readable representation of *buf in *s,
218 where each octet in *buf is represented by a 2-digit
219 hexadecimal number in *s. */
220
221 asn1_error_code asn12krb5_buf
222 (const asn1buf *buf, krb5_data **code);
223 /* modifies *code
224 effects Instantiates **code with the krb5_data representation of **buf. */
225
226
227 int asn1buf_remains
228 (asn1buf *buf, int indef);
229 /* requires *buf is a buffer containing an asn.1 structure or array
230 modifies *buf
231 effects Returns the number of unprocessed octets remaining in *buf. */
232
233 #endif
234