sshbuf-getput-basic.c revision 1.2 
1/*	$OpenBSD: sshbuf-getput-basic.c,v 1.2 2014/12/04 01:49:59 djm Exp $	*/
2/*
3 * Copyright (c) 2011 Damien Miller
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18#include <sys/types.h>
19#include <stdlib.h>
20#include <stdio.h>
21#include <string.h>
22
23#include "ssherr.h"
24#define SSHBUF_INTERNAL
25#include "sshbuf.h"
26
27int
28sshbuf_get(struct sshbuf *buf, void *v, size_t len)
29{
30	const u_char *p = sshbuf_ptr(buf);
31	int r;
32
33	if ((r = sshbuf_consume(buf, len)) < 0)
34		return r;
35	if (v != NULL)
36		memcpy(v, p, len);
37	return 0;
38}
39
40int
41sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp)
42{
43	const u_char *p = sshbuf_ptr(buf);
44	int r;
45
46	if ((r = sshbuf_consume(buf, 8)) < 0)
47		return r;
48	if (valp != NULL)
49		*valp = PEEK_U64(p);
50	return 0;
51}
52
53int
54sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp)
55{
56	const u_char *p = sshbuf_ptr(buf);
57	int r;
58
59	if ((r = sshbuf_consume(buf, 4)) < 0)
60		return r;
61	if (valp != NULL)
62		*valp = PEEK_U32(p);
63	return 0;
64}
65
66int
67sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp)
68{
69	const u_char *p = sshbuf_ptr(buf);
70	int r;
71
72	if ((r = sshbuf_consume(buf, 2)) < 0)
73		return r;
74	if (valp != NULL)
75		*valp = PEEK_U16(p);
76	return 0;
77}
78
79int
80sshbuf_get_u8(struct sshbuf *buf, u_char *valp)
81{
82	const u_char *p = sshbuf_ptr(buf);
83	int r;
84
85	if ((r = sshbuf_consume(buf, 1)) < 0)
86		return r;
87	if (valp != NULL)
88		*valp = (u_int8_t)*p;
89	return 0;
90}
91
92int
93sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp)
94{
95	const u_char *val;
96	size_t len;
97	int r;
98
99	if (valp != NULL)
100		*valp = NULL;
101	if (lenp != NULL)
102		*lenp = 0;
103	if ((r = sshbuf_get_string_direct(buf, &val, &len)) < 0)
104		return r;
105	if (valp != NULL) {
106		if ((*valp = malloc(len + 1)) == NULL) {
107			SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL"));
108			return SSH_ERR_ALLOC_FAIL;
109		}
110		memcpy(*valp, val, len);
111		(*valp)[len] = '\0';
112	}
113	if (lenp != NULL)
114		*lenp = len;
115	return 0;
116}
117
118int
119sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp, size_t *lenp)
120{
121	size_t len;
122	const u_char *p;
123	int r;
124
125	if (valp != NULL)
126		*valp = NULL;
127	if (lenp != NULL)
128		*lenp = 0;
129	if ((r = sshbuf_peek_string_direct(buf, &p, &len)) < 0)
130		return r;
131	if (valp != 0)
132		*valp = p;
133	if (lenp != NULL)
134		*lenp = len;
135	if (sshbuf_consume(buf, len + 4) != 0) {
136		/* Shouldn't happen */
137		SSHBUF_DBG(("SSH_ERR_INTERNAL_ERROR"));
138		SSHBUF_ABORT();
139		return SSH_ERR_INTERNAL_ERROR;
140	}
141	return 0;
142}
143
144int
145sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp,
146    size_t *lenp)
147{
148	u_int32_t len;
149	const u_char *p = sshbuf_ptr(buf);
150
151	if (valp != NULL)
152		*valp = NULL;
153	if (lenp != NULL)
154		*lenp = 0;
155	if (sshbuf_len(buf) < 4) {
156		SSHBUF_DBG(("SSH_ERR_MESSAGE_INCOMPLETE"));
157		return SSH_ERR_MESSAGE_INCOMPLETE;
158	}
159	len = PEEK_U32(p);
160	if (len > SSHBUF_SIZE_MAX - 4) {
161		SSHBUF_DBG(("SSH_ERR_STRING_TOO_LARGE"));
162		return SSH_ERR_STRING_TOO_LARGE;
163	}
164	if (sshbuf_len(buf) - 4 < len) {
165		SSHBUF_DBG(("SSH_ERR_MESSAGE_INCOMPLETE"));
166		return SSH_ERR_MESSAGE_INCOMPLETE;
167	}
168	if (valp != 0)
169		*valp = p + 4;
170	if (lenp != NULL)
171		*lenp = len;
172	return 0;
173}
174
175int
176sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp)
177{
178	size_t len;
179	const u_char *p, *z;
180	int r;
181
182	if (valp != NULL)
183		*valp = NULL;
184	if (lenp != NULL)
185		*lenp = 0;
186	if ((r = sshbuf_peek_string_direct(buf, &p, &len)) != 0)
187		return r;
188	/* Allow a \0 only at the end of the string */
189	if (len > 0 &&
190	    (z = memchr(p , '\0', len)) != NULL && z < p + len - 1) {
191		SSHBUF_DBG(("SSH_ERR_INVALID_FORMAT"));
192		return SSH_ERR_INVALID_FORMAT;
193	}
194	if ((r = sshbuf_skip_string(buf)) != 0)
195		return -1;
196	if (valp != NULL) {
197		if ((*valp = malloc(len + 1)) == NULL) {
198			SSHBUF_DBG(("SSH_ERR_ALLOC_FAIL"));
199			return SSH_ERR_ALLOC_FAIL;
200		}
201		memcpy(*valp, p, len);
202		(*valp)[len] = '\0';
203	}
204	if (lenp != NULL)
205		*lenp = (size_t)len;
206	return 0;
207}
208
209int
210sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v)
211{
212	u_int32_t len;
213	u_char *p;
214	int r;
215
216	/*
217	 * Use sshbuf_peek_string_direct() to figure out if there is
218	 * a complete string in 'buf' and copy the string directly
219	 * into 'v'.
220	 */
221	if ((r = sshbuf_peek_string_direct(buf, NULL, NULL)) != 0 ||
222	    (r = sshbuf_get_u32(buf, &len)) != 0 ||
223	    (r = sshbuf_reserve(v, len, &p)) != 0 ||
224	    (r = sshbuf_get(buf, p, len)) != 0)
225		return r;
226	return 0;
227}
228
229int
230sshbuf_put(struct sshbuf *buf, const void *v, size_t len)
231{
232	u_char *p;
233	int r;
234
235	if ((r = sshbuf_reserve(buf, len, &p)) < 0)
236		return r;
237	memcpy(p, v, len);
238	return 0;
239}
240
241int
242sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v)
243{
244	return sshbuf_put(buf, sshbuf_ptr(v), sshbuf_len(v));
245}
246
247int
248sshbuf_putf(struct sshbuf *buf, const char *fmt, ...)
249{
250	va_list ap;
251	int r;
252
253	va_start(ap, fmt);
254	r = sshbuf_putfv(buf, fmt, ap);
255	va_end(ap);
256	return r;
257}
258
259int
260sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap)
261{
262	va_list ap2;
263	int r, len;
264	u_char *p;
265
266	va_copy(ap2, ap);
267	if ((len = vsnprintf(NULL, 0, fmt, ap2)) < 0) {
268		r = SSH_ERR_INVALID_ARGUMENT;
269		goto out;
270	}
271	if (len == 0) {
272		r = 0;
273		goto out; /* Nothing to do */
274	}
275	va_end(ap2);
276	va_copy(ap2, ap);
277	if ((r = sshbuf_reserve(buf, (size_t)len + 1, &p)) < 0)
278		goto out;
279	if ((r = vsnprintf((char *)p, len + 1, fmt, ap2)) != len) {
280		r = SSH_ERR_INTERNAL_ERROR;
281		goto out; /* Shouldn't happen */
282	}
283	/* Consume terminating \0 */
284	if ((r = sshbuf_consume_end(buf, 1)) != 0)
285		goto out;
286	r = 0;
287 out:
288	va_end(ap2);
289	return r;
290}
291
292int
293sshbuf_put_u64(struct sshbuf *buf, u_int64_t val)
294{
295	u_char *p;
296	int r;
297
298	if ((r = sshbuf_reserve(buf, 8, &p)) < 0)
299		return r;
300	POKE_U64(p, val);
301	return 0;
302}
303
304int
305sshbuf_put_u32(struct sshbuf *buf, u_int32_t val)
306{
307	u_char *p;
308	int r;
309
310	if ((r = sshbuf_reserve(buf, 4, &p)) < 0)
311		return r;
312	POKE_U32(p, val);
313	return 0;
314}
315
316int
317sshbuf_put_u16(struct sshbuf *buf, u_int16_t val)
318{
319	u_char *p;
320	int r;
321
322	if ((r = sshbuf_reserve(buf, 2, &p)) < 0)
323		return r;
324	POKE_U16(p, val);
325	return 0;
326}
327
328int
329sshbuf_put_u8(struct sshbuf *buf, u_char val)
330{
331	u_char *p;
332	int r;
333
334	if ((r = sshbuf_reserve(buf, 1, &p)) < 0)
335		return r;
336	p[0] = val;
337	return 0;
338}
339
340int
341sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len)
342{
343	u_char *d;
344	int r;
345
346	if (len > SSHBUF_SIZE_MAX - 4) {
347		SSHBUF_DBG(("SSH_ERR_NO_BUFFER_SPACE"));
348		return SSH_ERR_NO_BUFFER_SPACE;
349	}
350	if ((r = sshbuf_reserve(buf, len + 4, &d)) < 0)
351		return r;
352	POKE_U32(d, len);
353	memcpy(d + 4, v, len);
354	return 0;
355}
356
357int
358sshbuf_put_cstring(struct sshbuf *buf, const char *v)
359{
360	return sshbuf_put_string(buf, (u_char *)v, v == NULL ? 0 : strlen(v));
361}
362
363int
364sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v)
365{
366	return sshbuf_put_string(buf, sshbuf_ptr(v), sshbuf_len(v));
367}
368
369int
370sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp)
371{
372	const u_char *p;
373	size_t len;
374	struct sshbuf *ret;
375	int r;
376
377	if (buf == NULL || bufp == NULL)
378		return SSH_ERR_INVALID_ARGUMENT;
379	*bufp = NULL;
380	if ((r = sshbuf_peek_string_direct(buf, &p, &len)) != 0)
381		return r;
382	if ((ret = sshbuf_from(p, len)) == NULL)
383		return SSH_ERR_ALLOC_FAIL;
384	if ((r = sshbuf_consume(buf, len + 4)) != 0 ||  /* Shouldn't happen */
385	    (r = sshbuf_set_parent(ret, buf)) != 0) {
386		sshbuf_free(ret);
387		return r;
388	}
389	*bufp = ret;
390	return 0;
391}
392
393int
394sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len)
395{
396	u_char *d;
397	const u_char *s = (const u_char *)v;
398	int r, prepend;
399
400	if (len > SSHBUF_SIZE_MAX - 5) {
401		SSHBUF_DBG(("SSH_ERR_NO_BUFFER_SPACE"));
402		return SSH_ERR_NO_BUFFER_SPACE;
403	}
404	/* Skip leading zero bytes */
405	for (; len > 0 && *s == 0; len--, s++)
406		;
407	/*
408	 * If most significant bit is set then prepend a zero byte to
409	 * avoid interpretation as a negative number.
410	 */
411	prepend = len > 0 && (s[0] & 0x80) != 0;
412	if ((r = sshbuf_reserve(buf, len + 4 + prepend, &d)) < 0)
413		return r;
414	POKE_U32(d, len + prepend);
415	if (prepend)
416		d[4] = 0;
417	memcpy(d + 4 + prepend, s, len);
418	return 0;
419}
420