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markus@openbsd.orgcb30cd42018-07-09 21:56:06 +00001/* $OpenBSD: sshbuf.h,v 1.11 2018/07/09 21:56:06 markus 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
Damien Miller05e82c32014-05-15 14:33:43 +100053/*
54 * Create a new sshbuf buffer.
55 * Returns pointer to buffer on success, or NULL on allocation failure.
56 */
57struct sshbuf *sshbuf_new(void);
58
59/*
60 * Create a new, read-only sshbuf buffer from existing data.
61 * Returns pointer to buffer on success, or NULL on allocation failure.
62 */
63struct sshbuf *sshbuf_from(const void *blob, size_t len);
64
65/*
66 * Create a new, read-only sshbuf buffer from the contents of an existing
67 * buffer. The contents of "buf" must not change in the lifetime of the
68 * resultant buffer.
69 * Returns pointer to buffer on success, or NULL on allocation failure.
70 */
71struct sshbuf *sshbuf_fromb(struct sshbuf *buf);
72
73/*
74 * Create a new, read-only sshbuf buffer from the contents of a string in
75 * an existing buffer (the string is consumed in the process).
76 * The contents of "buf" must not change in the lifetime of the resultant
77 * buffer.
78 * Returns pointer to buffer on success, or NULL on allocation failure.
79 */
80int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp);
81
82/*
83 * Clear and free buf
84 */
85void sshbuf_free(struct sshbuf *buf);
86
87/*
88 * Reset buf, clearing its contents. NB. max_size is preserved.
89 */
90void sshbuf_reset(struct sshbuf *buf);
91
92/*
93 * Return the maximum size of buf
94 */
95size_t sshbuf_max_size(const struct sshbuf *buf);
96
97/*
98 * Set the maximum size of buf
99 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
100 */
101int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size);
102
103/*
104 * Returns the length of data in buf
105 */
106size_t sshbuf_len(const struct sshbuf *buf);
107
108/*
109 * Returns number of bytes left in buffer before hitting max_size.
110 */
111size_t sshbuf_avail(const struct sshbuf *buf);
112
113/*
mmcc@openbsd.org8e56dd42015-12-10 07:01:35 +0000114 * Returns a read-only pointer to the start of the data in buf
Damien Miller05e82c32014-05-15 14:33:43 +1000115 */
116const u_char *sshbuf_ptr(const struct sshbuf *buf);
117
118/*
mmcc@openbsd.org8e56dd42015-12-10 07:01:35 +0000119 * Returns a mutable pointer to the start of the data in buf, or
Damien Miller05e82c32014-05-15 14:33:43 +1000120 * NULL if the buffer is read-only.
121 */
122u_char *sshbuf_mutable_ptr(const struct sshbuf *buf);
123
124/*
125 * Check whether a reservation of size len will succeed in buf
126 * Safer to use than direct comparisons again sshbuf_avail as it copes
127 * with unsigned overflows correctly.
128 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
129 */
130int sshbuf_check_reserve(const struct sshbuf *buf, size_t len);
131
132/*
djm@openbsd.orga9c74602016-11-25 23:22:04 +0000133 * Preallocates len additional bytes in buf.
134 * Useful for cases where the caller knows how many bytes will ultimately be
135 * required to avoid realloc in the buffer code.
136 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
137 */
138int sshbuf_allocate(struct sshbuf *buf, size_t len);
139
140/*
Damien Miller05e82c32014-05-15 14:33:43 +1000141 * Reserve len bytes in buf.
142 * Returns 0 on success and a pointer to the first reserved byte via the
143 * optional dpp parameter or a negative * SSH_ERR_* error code on failure.
144 */
145int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp);
146
147/*
148 * Consume len bytes from the start of buf
149 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
150 */
151int sshbuf_consume(struct sshbuf *buf, size_t len);
152
153/*
154 * Consume len bytes from the end of buf
155 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
156 */
157int sshbuf_consume_end(struct sshbuf *buf, size_t len);
158
159/* Extract or deposit some bytes */
160int sshbuf_get(struct sshbuf *buf, void *v, size_t len);
161int sshbuf_put(struct sshbuf *buf, const void *v, size_t len);
162int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v);
163
164/* Append using a printf(3) format */
165int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...)
166 __attribute__((format(printf, 2, 3)));
167int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap);
168
169/* Functions to extract or store big-endian words of various sizes */
170int sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp);
171int sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp);
172int sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp);
173int sshbuf_get_u8(struct sshbuf *buf, u_char *valp);
174int sshbuf_put_u64(struct sshbuf *buf, u_int64_t val);
175int sshbuf_put_u32(struct sshbuf *buf, u_int32_t val);
176int sshbuf_put_u16(struct sshbuf *buf, u_int16_t val);
177int sshbuf_put_u8(struct sshbuf *buf, u_char val);
178
179/*
180 * Functions to extract or store SSH wire encoded strings (u32 len || data)
181 * The "cstring" variants admit no \0 characters in the string contents.
182 * Caller must free *valp.
183 */
184int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp);
185int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp);
186int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v);
187int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len);
188int sshbuf_put_cstring(struct sshbuf *buf, const char *v);
189int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v);
190
191/*
192 * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to
193 * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the
194 * next sshbuf-modifying function call. Caller does not free.
195 */
196int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp,
197 size_t *lenp);
198
199/* Skip past a string */
200#define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL)
201
202/* Another variant: "peeks" into the buffer without modifying it */
203int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp,
204 size_t *lenp);
djm@openbsd.orgdbee4112017-09-12 06:32:07 +0000205/* XXX peek_u8 / peek_u32 */
Damien Miller05e82c32014-05-15 14:33:43 +1000206
207/*
208 * Functions to extract or store SSH wire encoded bignums and elliptic
209 * curve points.
210 */
Damien Miller88137902014-08-19 11:28:11 +1000211int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len);
Damien Millerb03ebe22015-01-15 03:08:58 +1100212int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf,
213 const u_char **valp, size_t *lenp);
Damien Miller88137902014-08-19 11:28:11 +1000214#ifdef WITH_OPENSSL
Damien Miller05e82c32014-05-15 14:33:43 +1000215int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v);
216int sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v);
Damien Miller05e82c32014-05-15 14:33:43 +1000217int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v);
218int sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v);
Damien Miller88137902014-08-19 11:28:11 +1000219# ifdef OPENSSL_HAS_ECC
Darren Tuckera54a0402014-06-11 07:58:35 +1000220int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g);
221int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v);
Damien Miller05e82c32014-05-15 14:33:43 +1000222int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g);
223int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v);
Damien Miller88137902014-08-19 11:28:11 +1000224# endif /* OPENSSL_HAS_ECC */
225#endif /* WITH_OPENSSL */
Damien Miller05e82c32014-05-15 14:33:43 +1000226
Damien Miller86687062014-07-02 15:28:02 +1000227/* Dump the contents of the buffer in a human-readable format */
Damien Miller05e82c32014-05-15 14:33:43 +1000228void sshbuf_dump(struct sshbuf *buf, FILE *f);
229
Damien Miller86687062014-07-02 15:28:02 +1000230/* Dump specified memory in a human-readable format */
231void sshbuf_dump_data(const void *s, size_t len, FILE *f);
232
Damien Miller05e82c32014-05-15 14:33:43 +1000233/* Return the hexadecimal representation of the contents of the buffer */
234char *sshbuf_dtob16(struct sshbuf *buf);
235
236/* Encode the contents of the buffer as base64 */
237char *sshbuf_dtob64(struct sshbuf *buf);
238
239/* Decode base64 data and append it to the buffer */
240int sshbuf_b64tod(struct sshbuf *buf, const char *b64);
241
djm@openbsd.org1a31d022016-05-02 08:49:03 +0000242/*
243 * Duplicate the contents of a buffer to a string (caller to free).
244 * Returns NULL on buffer error, or if the buffer contains a premature
245 * nul character.
246 */
247char *sshbuf_dup_string(struct sshbuf *buf);
248
Damien Miller05e82c32014-05-15 14:33:43 +1000249/* Macros for decoding/encoding integers */
250#define PEEK_U64(p) \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000251 (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \
252 ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \
253 ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \
254 ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \
255 ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \
256 ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \
257 ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \
258 (u_int64_t)(((const u_char *)(p))[7]))
Damien Miller05e82c32014-05-15 14:33:43 +1000259#define PEEK_U32(p) \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000260 (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \
261 ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \
262 ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \
263 (u_int32_t)(((const u_char *)(p))[3]))
Damien Miller05e82c32014-05-15 14:33:43 +1000264#define PEEK_U16(p) \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000265 (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \
266 (u_int16_t)(((const u_char *)(p))[1]))
Damien Miller05e82c32014-05-15 14:33:43 +1000267
268#define POKE_U64(p, v) \
269 do { \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000270 const u_int64_t __v = (v); \
271 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \
272 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \
273 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \
274 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \
275 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \
276 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \
277 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \
278 ((u_char *)(p))[7] = __v & 0xff; \
Damien Miller05e82c32014-05-15 14:33:43 +1000279 } while (0)
280#define POKE_U32(p, v) \
281 do { \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000282 const u_int32_t __v = (v); \
283 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \
284 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \
285 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \
286 ((u_char *)(p))[3] = __v & 0xff; \
Damien Miller05e82c32014-05-15 14:33:43 +1000287 } while (0)
288#define POKE_U16(p, v) \
289 do { \
djm@openbsd.orga7994b32015-11-11 04:56:39 +0000290 const u_int16_t __v = (v); \
291 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \
292 ((u_char *)(p))[1] = __v & 0xff; \
Damien Miller05e82c32014-05-15 14:33:43 +1000293 } while (0)
294
295/* Internal definitions follow. Exposed for regress tests */
296#ifdef SSHBUF_INTERNAL
297
298/*
299 * Return the allocation size of buf
300 */
301size_t sshbuf_alloc(const struct sshbuf *buf);
302
303/*
304 * Increment the reference count of buf.
305 */
306int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent);
307
308/*
309 * Return the parent buffer of buf, or NULL if it has no parent.
310 */
311const struct sshbuf *sshbuf_parent(const struct sshbuf *buf);
312
313/*
314 * Return the reference count of buf
315 */
316u_int sshbuf_refcount(const struct sshbuf *buf);
317
318# define SSHBUF_SIZE_INIT 256 /* Initial allocation */
319# define SSHBUF_SIZE_INC 256 /* Preferred increment length */
320# define SSHBUF_PACK_MIN 8192 /* Minimim packable offset */
321
322/* # define SSHBUF_ABORT abort */
323/* # define SSHBUF_DEBUG */
324
325# ifndef SSHBUF_ABORT
326# define SSHBUF_ABORT()
327# endif
328
329# ifdef SSHBUF_DEBUG
330# define SSHBUF_TELL(what) do { \
331 printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \
332 __FILE__, __LINE__, __func__, what, \
333 buf->size, buf->alloc, buf->off, buf->max_size); \
334 fflush(stdout); \
335 } while (0)
336# define SSHBUF_DBG(x) do { \
337 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \
338 printf x; \
339 printf("\n"); \
340 fflush(stdout); \
341 } while (0)
342# else
343# define SSHBUF_TELL(what)
344# define SSHBUF_DBG(x)
345# endif
346#endif /* SSHBUF_INTERNAL */
347
348#endif /* _SSHBUF_H */