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djm@openbsd.orgdbee4112017-09-12 06:32:07 +00001/* $OpenBSD: sshbuf.h,v 1.9 2017/09/12 06:32:07 djm Exp $ */
Damien Miller05e82c32014-05-15 14:33:43 +10002/*
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#ifndef _SSHBUF_H
19#define _SSHBUF_H
20
21#include <sys/types.h>
22#include <stdarg.h>
23#include <stdio.h>
Damien Miller88137902014-08-19 11:28:11 +100024#ifdef WITH_OPENSSL
25# include <openssl/bn.h>
26# ifdef OPENSSL_HAS_ECC
27# include <openssl/ec.h>
28# endif /* OPENSSL_HAS_ECC */
29#endif /* WITH_OPENSSL */
Damien Miller05e82c32014-05-15 14:33:43 +100030
31#define SSHBUF_SIZE_MAX 0x8000000 /* Hard maximum size */
32#define SSHBUF_REFS_MAX 0x100000 /* Max child buffers */
33#define SSHBUF_MAX_BIGNUM (16384 / 8) /* Max bignum *bytes* */
34#define SSHBUF_MAX_ECPOINT ((528 * 2 / 8) + 1) /* Max EC point *bytes* */
35
36/*
37 * NB. do not depend on the internals of this. It will be made opaque
38 * one day.
39 */
40struct sshbuf {
41 u_char *d; /* Data */
42 const u_char *cd; /* Const data */
43 size_t off; /* First available byte is buf->d + buf->off */
44 size_t size; /* Last byte is buf->d + buf->size - 1 */
45 size_t max_size; /* Maximum size of buffer */
46 size_t alloc; /* Total bytes allocated to buf->d */
47 int readonly; /* Refers to external, const data */
48 int dont_free; /* Kludge to support sshbuf_init */
49 u_int refcount; /* Tracks self and number of child buffers */
50 struct sshbuf *parent; /* If child, pointer to parent */
51};
52
53#ifndef SSHBUF_NO_DEPREACTED
54/*
55 * NB. Please do not use sshbuf_init() in new code. Please use sshbuf_new()
56 * instead. sshbuf_init() is deprectated and will go away soon (it is
57 * only included to allow compat with buffer_* in OpenSSH)
58 */
59void sshbuf_init(struct sshbuf *buf);
60#endif
61
62/*
63 * Create a new sshbuf buffer.
64 * Returns pointer to buffer on success, or NULL on allocation failure.
65 */
66struct sshbuf *sshbuf_new(void);
67
68/*
69 * Create a new, read-only sshbuf buffer from existing data.
70 * Returns pointer to buffer on success, or NULL on allocation failure.
71 */
72struct sshbuf *sshbuf_from(const void *blob, size_t len);
73
74/*
75 * Create a new, read-only sshbuf buffer from the contents of an existing
76 * buffer. The contents of "buf" must not change in the lifetime of the
77 * resultant buffer.
78 * Returns pointer to buffer on success, or NULL on allocation failure.
79 */
80struct sshbuf *sshbuf_fromb(struct sshbuf *buf);
81
82/*
83 * Create a new, read-only sshbuf buffer from the contents of a string in
84 * an existing buffer (the string is consumed in the process).
85 * The contents of "buf" must not change in the lifetime of the resultant
86 * buffer.
87 * Returns pointer to buffer on success, or NULL on allocation failure.
88 */
89int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp);
90
91/*
92 * Clear and free buf
93 */
94void sshbuf_free(struct sshbuf *buf);
95
96/*
97 * Reset buf, clearing its contents. NB. max_size is preserved.
98 */
99void sshbuf_reset(struct sshbuf *buf);
100
101/*
102 * Return the maximum size of buf
103 */
104size_t sshbuf_max_size(const struct sshbuf *buf);
105
106/*
107 * Set the maximum size of buf
108 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
109 */
110int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size);
111
112/*
113 * Returns the length of data in buf
114 */
115size_t sshbuf_len(const struct sshbuf *buf);
116
117/*
118 * Returns number of bytes left in buffer before hitting max_size.
119 */
120size_t sshbuf_avail(const struct sshbuf *buf);
121
122/*
mmcc@openbsd.org8e56dd42015-12-10 07:01:35 +0000123 * Returns a read-only pointer to the start of the data in buf
Damien Miller05e82c32014-05-15 14:33:43 +1000124 */
125const u_char *sshbuf_ptr(const struct sshbuf *buf);
126
127/*
mmcc@openbsd.org8e56dd42015-12-10 07:01:35 +0000128 * Returns a mutable pointer to the start of the data in buf, or
Damien Miller05e82c32014-05-15 14:33:43 +1000129 * NULL if the buffer is read-only.
130 */
131u_char *sshbuf_mutable_ptr(const struct sshbuf *buf);
132
133/*
134 * Check whether a reservation of size len will succeed in buf
135 * Safer to use than direct comparisons again sshbuf_avail as it copes
136 * with unsigned overflows correctly.
137 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
138 */
139int sshbuf_check_reserve(const struct sshbuf *buf, size_t len);
140
141/*
djm@openbsd.orga9c74602016-11-25 23:22:04 +0000142 * Preallocates len additional bytes in buf.
143 * Useful for cases where the caller knows how many bytes will ultimately be
144 * required to avoid realloc in the buffer code.
145 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
146 */
147int sshbuf_allocate(struct sshbuf *buf, size_t len);
148
149/*
Damien Miller05e82c32014-05-15 14:33:43 +1000150 * Reserve len bytes in buf.
151 * Returns 0 on success and a pointer to the first reserved byte via the
152 * optional dpp parameter or a negative * SSH_ERR_* error code on failure.
153 */
154int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp);
155
156/*
157 * Consume len bytes from the start of buf
158 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
159 */
160int sshbuf_consume(struct sshbuf *buf, size_t len);
161
162/*
163 * Consume len bytes from the end of buf
164 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
165 */
166int sshbuf_consume_end(struct sshbuf *buf, size_t len);
167
168/* Extract or deposit some bytes */
169int sshbuf_get(struct sshbuf *buf, void *v, size_t len);
170int sshbuf_put(struct sshbuf *buf, const void *v, size_t len);
171int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v);
172
173/* Append using a printf(3) format */
174int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...)
175 __attribute__((format(printf, 2, 3)));
176int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap);
177
178/* Functions to extract or store big-endian words of various sizes */
179int sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp);
180int sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp);
181int sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp);
182int sshbuf_get_u8(struct sshbuf *buf, u_char *valp);
183int sshbuf_put_u64(struct sshbuf *buf, u_int64_t val);
184int sshbuf_put_u32(struct sshbuf *buf, u_int32_t val);
185int sshbuf_put_u16(struct sshbuf *buf, u_int16_t val);
186int sshbuf_put_u8(struct sshbuf *buf, u_char val);
187
188/*
189 * Functions to extract or store SSH wire encoded strings (u32 len || data)
190 * The "cstring" variants admit no \0 characters in the string contents.
191 * Caller must free *valp.
192 */
193int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp);
194int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp);
195int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v);
196int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len);
197int sshbuf_put_cstring(struct sshbuf *buf, const char *v);
198int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v);
199
200/*
201 * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to
202 * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the
203 * next sshbuf-modifying function call. Caller does not free.
204 */
205int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp,
206 size_t *lenp);
207
208/* Skip past a string */
209#define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL)
210
211/* Another variant: "peeks" into the buffer without modifying it */
212int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp,
213 size_t *lenp);
djm@openbsd.orgdbee4112017-09-12 06:32:07 +0000214/* XXX peek_u8 / peek_u32 */
Damien Miller05e82c32014-05-15 14:33:43 +1000215
216/*
217 * Functions to extract or store SSH wire encoded bignums and elliptic
218 * curve points.
219 */
Damien Miller88137902014-08-19 11:28:11 +1000220int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len);
Damien Millerb03ebe22015-01-15 03:08:58 +1100221int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf,
222 const u_char **valp, size_t *lenp);
Damien Miller88137902014-08-19 11:28:11 +1000223#ifdef WITH_OPENSSL
Damien Miller05e82c32014-05-15 14:33:43 +1000224int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v);
225int sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v);
Damien Miller05e82c32014-05-15 14:33:43 +1000226int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v);
227int sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v);
Damien Miller88137902014-08-19 11:28:11 +1000228# ifdef OPENSSL_HAS_ECC
Darren Tuckera54a0402014-06-11 07:58:35 +1000229int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g);
230int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v);
Damien Miller05e82c32014-05-15 14:33:43 +1000231int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g);
232int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v);
Damien Miller88137902014-08-19 11:28:11 +1000233# endif /* OPENSSL_HAS_ECC */
234#endif /* WITH_OPENSSL */
Damien Miller05e82c32014-05-15 14:33:43 +1000235
Damien Miller86687062014-07-02 15:28:02 +1000236/* Dump the contents of the buffer in a human-readable format */
Damien Miller05e82c32014-05-15 14:33:43 +1000237void sshbuf_dump(struct sshbuf *buf, FILE *f);
238
Damien Miller86687062014-07-02 15:28:02 +1000239/* Dump specified memory in a human-readable format */
240void sshbuf_dump_data(const void *s, size_t len, FILE *f);
241
Damien Miller05e82c32014-05-15 14:33:43 +1000242/* Return the hexadecimal representation of the contents of the buffer */
243char *sshbuf_dtob16(struct sshbuf *buf);
244
245/* Encode the contents of the buffer as base64 */
246char *sshbuf_dtob64(struct sshbuf *buf);
247
248/* Decode base64 data and append it to the buffer */
249int sshbuf_b64tod(struct sshbuf *buf, const char *b64);
250
djm@openbsd.org1a31d022016-05-02 08:49:03 +0000251/*
252 * Duplicate the contents of a buffer to a string (caller to free).
253 * Returns NULL on buffer error, or if the buffer contains a premature
254 * nul character.
255 */
256char *sshbuf_dup_string(struct sshbuf *buf);
257
Damien Miller05e82c32014-05-15 14:33:43 +1000258/* Macros for decoding/encoding integers */
259#define PEEK_U64(p) \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000260 (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \
261 ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \
262 ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \
263 ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \
264 ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \
265 ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \
266 ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \
267 (u_int64_t)(((const u_char *)(p))[7]))
Damien Miller05e82c32014-05-15 14:33:43 +1000268#define PEEK_U32(p) \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000269 (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \
270 ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \
271 ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \
272 (u_int32_t)(((const u_char *)(p))[3]))
Damien Miller05e82c32014-05-15 14:33:43 +1000273#define PEEK_U16(p) \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000274 (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \
275 (u_int16_t)(((const u_char *)(p))[1]))
Damien Miller05e82c32014-05-15 14:33:43 +1000276
277#define POKE_U64(p, v) \
278 do { \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000279 const u_int64_t __v = (v); \
280 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \
281 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \
282 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \
283 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \
284 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \
285 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \
286 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \
287 ((u_char *)(p))[7] = __v & 0xff; \
Damien Miller05e82c32014-05-15 14:33:43 +1000288 } while (0)
289#define POKE_U32(p, v) \
290 do { \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000291 const u_int32_t __v = (v); \
292 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \
293 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \
294 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \
295 ((u_char *)(p))[3] = __v & 0xff; \
Damien Miller05e82c32014-05-15 14:33:43 +1000296 } while (0)
297#define POKE_U16(p, v) \
298 do { \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000299 const u_int16_t __v = (v); \
300 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \
301 ((u_char *)(p))[1] = __v & 0xff; \
Damien Miller05e82c32014-05-15 14:33:43 +1000302 } while (0)
303
304/* Internal definitions follow. Exposed for regress tests */
305#ifdef SSHBUF_INTERNAL
306
307/*
308 * Return the allocation size of buf
309 */
310size_t sshbuf_alloc(const struct sshbuf *buf);
311
312/*
313 * Increment the reference count of buf.
314 */
315int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent);
316
317/*
318 * Return the parent buffer of buf, or NULL if it has no parent.
319 */
320const struct sshbuf *sshbuf_parent(const struct sshbuf *buf);
321
322/*
323 * Return the reference count of buf
324 */
325u_int sshbuf_refcount(const struct sshbuf *buf);
326
327# define SSHBUF_SIZE_INIT 256 /* Initial allocation */
328# define SSHBUF_SIZE_INC 256 /* Preferred increment length */
329# define SSHBUF_PACK_MIN 8192 /* Minimim packable offset */
330
331/* # define SSHBUF_ABORT abort */
332/* # define SSHBUF_DEBUG */
333
334# ifndef SSHBUF_ABORT
335# define SSHBUF_ABORT()
336# endif
337
338# ifdef SSHBUF_DEBUG
339# define SSHBUF_TELL(what) do { \
340 printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \
341 __FILE__, __LINE__, __func__, what, \
342 buf->size, buf->alloc, buf->off, buf->max_size); \
343 fflush(stdout); \
344 } while (0)
345# define SSHBUF_DBG(x) do { \
346 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \
347 printf x; \
348 printf("\n"); \
349 fflush(stdout); \
350 } while (0)
351# else
352# define SSHBUF_TELL(what)
353# define SSHBUF_DBG(x)
354# endif
355#endif /* SSHBUF_INTERNAL */
356
357#endif /* _SSHBUF_H */