8ea6c8e42080e192449aa399e789bd016b0be37f
[strongswan.git] / src / libstrongswan / chunk.h
1 /*
2 * Copyright (C) 2008-2009 Tobias Brunner
3 * Copyright (C) 2005-2008 Martin Willi
4 * Copyright (C) 2005 Jan Hutter
5 * Hochschule fuer Technik Rapperswil
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 */
17
18 /**
19 * @defgroup chunk chunk
20 * @{ @ingroup libstrongswan
21 */
22
23 #ifndef CHUNK_H_
24 #define CHUNK_H_
25
26 #include <string.h>
27 #include <stdarg.h>
28 #include <sys/types.h>
29 #ifdef HAVE_ALLOCA_H
30 #include <alloca.h>
31 #endif
32
33 typedef struct chunk_t chunk_t;
34
35 /**
36 * General purpose pointer/length abstraction.
37 */
38 struct chunk_t {
39 /** Pointer to start of data */
40 u_char *ptr;
41 /** Length of data in bytes */
42 size_t len;
43 };
44
45 #include <utils.h>
46
47 /**
48 * A { NULL, 0 }-chunk handy for initialization.
49 */
50 extern chunk_t chunk_empty;
51
52 /**
53 * Create a new chunk pointing to "ptr" with length "len"
54 */
55 static inline chunk_t chunk_create(u_char *ptr, size_t len)
56 {
57 chunk_t chunk = {ptr, len};
58 return chunk;
59 }
60
61 /**
62 * Create a clone of a chunk pointing to "ptr"
63 */
64 chunk_t chunk_create_clone(u_char *ptr, chunk_t chunk);
65
66 /**
67 * Calculate length of multiple chunks
68 */
69 size_t chunk_length(const char *mode, ...);
70
71 /**
72 * Concatenate chunks into a chunk pointing to "ptr".
73 *
74 * The mode string specifies the number of chunks, and how to handle each of
75 * them with a single character: 'c' for copy (allocate new chunk), 'm' for move
76 * (free given chunk) or 's' for sensitive-move (clear given chunk, then free).
77 */
78 chunk_t chunk_create_cat(u_char *ptr, const char* mode, ...);
79
80 /**
81 * Split up a chunk into parts, "mode" is a string of "a" (alloc),
82 * "c" (copy) and "m" (move). Each letter say for the corresponding chunk if
83 * it should get allocated on heap, copied into existing chunk, or the chunk
84 * should point into "chunk". The length of each part is an argument before
85 * each target chunk. E.g.:
86 * chunk_split(chunk, "mcac", 3, &a, 7, &b, 5, &c, d.len, &d);
87 */
88 void chunk_split(chunk_t chunk, const char *mode, ...);
89
90 /**
91 * Write the binary contents of a chunk_t to a file
92 *
93 * @param chunk contents to write to file
94 * @param path path where file is written to
95 * @param label label specifying file type
96 * @param mask file mode creation mask
97 * @param force overwrite existing file by force
98 * @return TRUE if write operation was successful
99 */
100 bool chunk_write(chunk_t chunk, char *path, char *label, mode_t mask, bool force);
101
102 /**
103 * Convert a chunk of data to hex encoding.
104 *
105 * The resulting string is '\\0' terminated, but the chunk does not include
106 * the '\\0'. If buf is supplied, it must hold at least (chunk.len * 2 + 1).
107 *
108 * @param chunk data to convert to hex encoding
109 * @param buf buffer to write to, NULL to malloc
110 * @param uppercase TRUE to use uppercase letters
111 * @return chunk of encoded data
112 */
113 chunk_t chunk_to_hex(chunk_t chunk, char *buf, bool uppercase);
114
115 /**
116 * Convert a hex encoded in a binary chunk.
117 *
118 * If buf is supplied, it must hold at least (hex.len / 2) + (hex.len % 2)
119 * bytes. It is filled by the right to give correct values for short inputs.
120 *
121 * @param hex hex encoded input data
122 * @param buf buffer to write decoded data, NULL to malloc
123 * @return converted data
124 */
125 chunk_t chunk_from_hex(chunk_t hex, char *buf);
126
127 /**
128 * Convert a chunk of data to its base64 encoding.
129 *
130 * The resulting string is '\\0' terminated, but the chunk does not include
131 * the '\\0'. If buf is supplied, it must hold at least (chunk.len * 4 / 3 + 1).
132 *
133 * @param chunk data to convert
134 * @param buf buffer to write to, NULL to malloc
135 * @return chunk of encoded data
136 */
137 chunk_t chunk_to_base64(chunk_t chunk, char *buf);
138
139 /**
140 * Convert a base64 in a binary chunk.
141 *
142 * If buf is supplied, it must hold at least (base64.len / 4 * 3).
143 *
144 * @param base64 base64 encoded input data
145 * @param buf buffer to write decoded data, NULL to malloc
146 * @return converted data
147 */
148 chunk_t chunk_from_base64(chunk_t base64, char *buf);
149
150 /**
151 * Free contents of a chunk
152 */
153 static inline void chunk_free(chunk_t *chunk)
154 {
155 free(chunk->ptr);
156 *chunk = chunk_empty;
157 }
158
159 /**
160 * Overwrite the contents of a chunk and free it
161 */
162 static inline void chunk_clear(chunk_t *chunk)
163 {
164 if (chunk->ptr)
165 {
166 memset(chunk->ptr, 0, chunk->len);
167 chunk_free(chunk);
168 }
169 }
170
171 /**
172 * Initialize a chunk to point to buffer inspectable by sizeof()
173 */
174 #define chunk_from_buf(str) { str, sizeof(str) }
175
176 /**
177 * Initialize a chunk to point to a thing
178 */
179 #define chunk_from_thing(thing) chunk_create((char*)&(thing), sizeof(thing))
180
181 /**
182 * Allocate a chunk on the heap
183 */
184 #define chunk_alloc(bytes) chunk_create(malloc(bytes), bytes)
185
186 /**
187 * Allocate a chunk on the stack
188 */
189 #define chunk_alloca(bytes) chunk_create(alloca(bytes), bytes)
190
191 /**
192 * Clone a chunk on heap
193 */
194 #define chunk_clone(chunk) chunk_create_clone((chunk).len ? malloc((chunk).len) : NULL, chunk)
195
196 /**
197 * Clone a chunk on stack
198 */
199 #define chunk_clonea(chunk) chunk_create_clone(alloca((chunk).len), chunk)
200
201 /**
202 * Concatenate chunks into a chunk on heap
203 */
204 #define chunk_cat(mode, ...) chunk_create_cat(malloc(chunk_length(mode, __VA_ARGS__)), mode, __VA_ARGS__)
205
206 /**
207 * Concatenate chunks into a chunk on stack
208 */
209 #define chunk_cata(mode, ...) chunk_create_cat(alloca(chunk_length(mode, __VA_ARGS__)), mode, __VA_ARGS__)
210
211 /**
212 * Skip n bytes in chunk (forward pointer, shorten length)
213 */
214 static inline chunk_t chunk_skip(chunk_t chunk, size_t bytes)
215 {
216 if (chunk.len > bytes)
217 {
218 chunk.ptr += bytes;
219 chunk.len -= bytes;
220 return chunk;
221 }
222 return chunk_empty;
223 }
224
225 /**
226 * Compare two chunks, returns zero if a equals b
227 * or negative/positive if a is small/greater than b
228 */
229 int chunk_compare(chunk_t a, chunk_t b);
230
231 /**
232 * Compare two chunks for equality,
233 * NULL chunks are never equal.
234 */
235 static inline bool chunk_equals(chunk_t a, chunk_t b)
236 {
237 return a.ptr != NULL && b.ptr != NULL &&
238 a.len == b.len && memeq(a.ptr, b.ptr, a.len);
239 }
240
241 /**
242 * Increment a chunk, as it would reprensent a network order integer.
243 *
244 * @param chunk chunk to increment
245 * @return TRUE if an overflow occured
246 */
247 bool chunk_increment(chunk_t chunk);
248
249 /**
250 * Check if a chunk has printable characters only.
251 *
252 * If sane is given, chunk is cloned into sane and all non printable characters
253 * get replaced by "replace".
254 *
255 * @param chunk chunk to check for printability
256 * @param sane pointer where sane version is allocated, or NULL
257 * @param replace character to use for replaceing unprintable characters
258 * @return TRUE if all characters in chunk are printable
259 */
260 bool chunk_printable(chunk_t chunk, chunk_t *sane, char replace);
261
262 /**
263 * Computes a 32 bit hash of the given chunk.
264 * Note: This hash is only intended for hash tables not for cryptographic purposes.
265 */
266 u_int32_t chunk_hash(chunk_t chunk);
267
268 /**
269 * Incremental version of chunk_hash. Use this to hash two or more chunks.
270 */
271 u_int32_t chunk_hash_inc(chunk_t chunk, u_int32_t hash);
272
273 /**
274 * printf hook function for chunk_t.
275 *
276 * Arguments are:
277 * chunk_t *chunk
278 * Use #-modifier to print a compact version
279 */
280 int chunk_printf_hook(char *dst, size_t len, printf_hook_spec_t *spec,
281 const void *const *args);
282
283 #endif /** CHUNK_H_ @}*/