1 /* $OpenBSD: sshbuf.h,v 1.27 2022/05/25 06:03:44 djm Exp $ */
3 * Copyright (c) 2011 Damien Miller
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.
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.
21 #include <sys/types.h>
25 # include <openssl/bn.h>
26 # ifdef OPENSSL_HAS_ECC
27 # include <openssl/ec.h>
28 # endif /* OPENSSL_HAS_ECC */
29 #endif /* WITH_OPENSSL */
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* */
37 * NB. do not depend on the internals of this. It will be made opaque
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 */
54 * Create a new sshbuf buffer.
55 * Returns pointer to buffer on success, or NULL on allocation failure.
57 struct sshbuf
*sshbuf_new(void);
60 * Create a new, read-only sshbuf buffer from existing data.
61 * Returns pointer to buffer on success, or NULL on allocation failure.
63 struct sshbuf
*sshbuf_from(const void *blob
, size_t len
);
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
69 * Returns pointer to buffer on success, or NULL on allocation failure.
71 struct sshbuf
*sshbuf_fromb(struct sshbuf
*buf
);
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
78 * Returns pointer to buffer on success, or NULL on allocation failure.
80 int sshbuf_froms(struct sshbuf
*buf
, struct sshbuf
**bufp
);
85 void sshbuf_free(struct sshbuf
*buf
);
88 * Reset buf, clearing its contents. NB. max_size is preserved.
90 void sshbuf_reset(struct sshbuf
*buf
);
93 * Return the maximum size of buf
95 size_t sshbuf_max_size(const struct sshbuf
*buf
);
98 * Set the maximum size of buf
99 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
101 int sshbuf_set_max_size(struct sshbuf
*buf
, size_t max_size
);
104 * Returns the length of data in buf
106 size_t sshbuf_len(const struct sshbuf
*buf
);
109 * Returns number of bytes left in buffer before hitting max_size.
111 size_t sshbuf_avail(const struct sshbuf
*buf
);
114 * Returns a read-only pointer to the start of the data in buf
116 const u_char
*sshbuf_ptr(const struct sshbuf
*buf
);
119 * Returns a mutable pointer to the start of the data in buf, or
120 * NULL if the buffer is read-only.
122 u_char
*sshbuf_mutable_ptr(const struct sshbuf
*buf
);
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.
130 int sshbuf_check_reserve(const struct sshbuf
*buf
, size_t len
);
133 * 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.
138 int sshbuf_allocate(struct sshbuf
*buf
, size_t len
);
141 * 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.
145 int sshbuf_reserve(struct sshbuf
*buf
, size_t len
, u_char
**dpp
);
148 * Consume len bytes from the start of buf
149 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
151 int sshbuf_consume(struct sshbuf
*buf
, size_t len
);
154 * Consume len bytes from the end of buf
155 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
157 int sshbuf_consume_end(struct sshbuf
*buf
, size_t len
);
159 /* Extract or deposit some bytes */
160 int sshbuf_get(struct sshbuf
*buf
, void *v
, size_t len
);
161 int sshbuf_put(struct sshbuf
*buf
, const void *v
, size_t len
);
162 int sshbuf_putb(struct sshbuf
*buf
, const struct sshbuf
*v
);
164 /* Append using a printf(3) format */
165 int sshbuf_putf(struct sshbuf
*buf
, const char *fmt
, ...)
166 __attribute__((format(printf
, 2, 3)));
167 int sshbuf_putfv(struct sshbuf
*buf
, const char *fmt
, va_list ap
);
169 /* Functions to extract or store big-endian words of various sizes */
170 int sshbuf_get_u64(struct sshbuf
*buf
, u_int64_t
*valp
);
171 int sshbuf_get_u32(struct sshbuf
*buf
, u_int32_t
*valp
);
172 int sshbuf_get_u16(struct sshbuf
*buf
, u_int16_t
*valp
);
173 int sshbuf_get_u8(struct sshbuf
*buf
, u_char
*valp
);
174 int sshbuf_put_u64(struct sshbuf
*buf
, u_int64_t val
);
175 int sshbuf_put_u32(struct sshbuf
*buf
, u_int32_t val
);
176 int sshbuf_put_u16(struct sshbuf
*buf
, u_int16_t val
);
177 int sshbuf_put_u8(struct sshbuf
*buf
, u_char val
);
179 /* Functions to peek at the contents of a buffer without modifying it. */
180 int sshbuf_peek_u64(const struct sshbuf
*buf
, size_t offset
,
182 int sshbuf_peek_u32(const struct sshbuf
*buf
, size_t offset
,
184 int sshbuf_peek_u16(const struct sshbuf
*buf
, size_t offset
,
186 int sshbuf_peek_u8(const struct sshbuf
*buf
, size_t offset
,
190 * Functions to poke values into an existing buffer (e.g. a length header
191 * to a packet). The destination bytes must already exist in the buffer.
193 int sshbuf_poke_u64(struct sshbuf
*buf
, size_t offset
, u_int64_t val
);
194 int sshbuf_poke_u32(struct sshbuf
*buf
, size_t offset
, u_int32_t val
);
195 int sshbuf_poke_u16(struct sshbuf
*buf
, size_t offset
, u_int16_t val
);
196 int sshbuf_poke_u8(struct sshbuf
*buf
, size_t offset
, u_char val
);
197 int sshbuf_poke(struct sshbuf
*buf
, size_t offset
, void *v
, size_t len
);
200 * Functions to extract or store SSH wire encoded strings (u32 len || data)
201 * The "cstring" variants admit no \0 characters in the string contents.
202 * Caller must free *valp.
204 int sshbuf_get_string(struct sshbuf
*buf
, u_char
**valp
, size_t *lenp
);
205 int sshbuf_get_cstring(struct sshbuf
*buf
, char **valp
, size_t *lenp
);
206 int sshbuf_get_stringb(struct sshbuf
*buf
, struct sshbuf
*v
);
207 int sshbuf_put_string(struct sshbuf
*buf
, const void *v
, size_t len
);
208 int sshbuf_put_cstring(struct sshbuf
*buf
, const char *v
);
209 int sshbuf_put_stringb(struct sshbuf
*buf
, const struct sshbuf
*v
);
212 * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to
213 * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the
214 * next sshbuf-modifying function call. Caller does not free.
216 int sshbuf_get_string_direct(struct sshbuf
*buf
, const u_char
**valp
,
219 /* Skip past a string */
220 #define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL)
222 /* Another variant: "peeks" into the buffer without modifying it */
223 int sshbuf_peek_string_direct(const struct sshbuf
*buf
, const u_char
**valp
,
227 * Functions to extract or store SSH wire encoded bignums and elliptic
230 int sshbuf_put_bignum2_bytes(struct sshbuf
*buf
, const void *v
, size_t len
);
231 int sshbuf_get_bignum2_bytes_direct(struct sshbuf
*buf
,
232 const u_char
**valp
, size_t *lenp
);
234 int sshbuf_get_bignum2(struct sshbuf
*buf
, BIGNUM
**valp
);
235 int sshbuf_put_bignum2(struct sshbuf
*buf
, const BIGNUM
*v
);
236 # ifdef OPENSSL_HAS_ECC
237 int sshbuf_get_ec(struct sshbuf
*buf
, EC_POINT
*v
, const EC_GROUP
*g
);
238 int sshbuf_get_eckey(struct sshbuf
*buf
, EC_KEY
*v
);
239 int sshbuf_put_ec(struct sshbuf
*buf
, const EC_POINT
*v
, const EC_GROUP
*g
);
240 int sshbuf_put_eckey(struct sshbuf
*buf
, const EC_KEY
*v
);
241 # endif /* OPENSSL_HAS_ECC */
242 #endif /* WITH_OPENSSL */
244 /* Dump the contents of the buffer in a human-readable format */
245 void sshbuf_dump(const struct sshbuf
*buf
, FILE *f
);
247 /* Dump specified memory in a human-readable format */
248 void sshbuf_dump_data(const void *s
, size_t len
, FILE *f
);
250 /* Return the hexadecimal representation of the contents of the buffer */
251 char *sshbuf_dtob16(struct sshbuf
*buf
);
253 /* Encode the contents of the buffer as base64 */
254 char *sshbuf_dtob64_string(const struct sshbuf
*buf
, int wrap
);
255 int sshbuf_dtob64(const struct sshbuf
*d
, struct sshbuf
*b64
, int wrap
);
256 /* RFC4648 "base64url" encoding variant */
257 int sshbuf_dtourlb64(const struct sshbuf
*d
, struct sshbuf
*b64
, int wrap
);
259 /* Decode base64 data and append it to the buffer */
260 int sshbuf_b64tod(struct sshbuf
*buf
, const char *b64
);
263 * Tests whether the buffer contains the specified byte sequence at the
264 * specified offset. Returns 0 on successful match, or a ssherr.h code
265 * otherwise. SSH_ERR_INVALID_FORMAT indicates sufficient bytes were
266 * present but the buffer contents did not match those supplied. Zero-
267 * length comparisons are not allowed.
269 * If sufficient data is present to make a comparison, then it is
270 * performed with timing independent of the value of the data. If
271 * insufficient data is present then the comparison is not attempted at
274 int sshbuf_cmp(const struct sshbuf
*b
, size_t offset
,
275 const void *s
, size_t len
);
278 * Searches the buffer for the specified string. Returns 0 on success
279 * and updates *offsetp with the offset of the first match, relative to
280 * the start of the buffer. Otherwise sshbuf_find will return a ssherr.h
281 * error code. SSH_ERR_INVALID_FORMAT indicates sufficient bytes were
282 * present in the buffer for a match to be possible but none was found.
283 * Searches for zero-length data are not allowed.
286 sshbuf_find(const struct sshbuf
*b
, size_t start_offset
,
287 const void *s
, size_t len
, size_t *offsetp
);
290 * Duplicate the contents of a buffer to a string (caller to free).
291 * Returns NULL on buffer error, or if the buffer contains a premature
294 char *sshbuf_dup_string(struct sshbuf
*buf
);
297 * Fill a buffer from a file descriptor or filename. Both allocate the
298 * buffer for the caller.
300 int sshbuf_load_fd(int, struct sshbuf
**)
301 __attribute__((__nonnull__ (2)));
302 int sshbuf_load_file(const char *, struct sshbuf
**)
303 __attribute__((__nonnull__ (2)));
306 * Write a buffer to a path, creating/truncating as needed (mode 0644,
307 * subject to umask). The buffer contents are not modified.
309 int sshbuf_write_file(const char *path
, struct sshbuf
*buf
)
310 __attribute__((__nonnull__ (2)));
312 /* Read up to maxlen bytes from a fd directly to a buffer */
313 int sshbuf_read(int, struct sshbuf
*, size_t, size_t *)
314 __attribute__((__nonnull__ (2)));
316 /* Macros for decoding/encoding integers */
317 #define PEEK_U64(p) \
318 (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \
319 ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \
320 ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \
321 ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \
322 ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \
323 ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \
324 ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \
325 (u_int64_t)(((const u_char *)(p))[7]))
326 #define PEEK_U32(p) \
327 (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \
328 ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \
329 ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \
330 (u_int32_t)(((const u_char *)(p))[3]))
331 #define PEEK_U16(p) \
332 (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \
333 (u_int16_t)(((const u_char *)(p))[1]))
335 #define POKE_U64(p, v) \
337 const u_int64_t __v = (v); \
338 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \
339 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \
340 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \
341 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \
342 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \
343 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \
344 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \
345 ((u_char *)(p))[7] = __v & 0xff; \
347 #define POKE_U32(p, v) \
349 const u_int32_t __v = (v); \
350 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \
351 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \
352 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \
353 ((u_char *)(p))[3] = __v & 0xff; \
355 #define POKE_U16(p, v) \
357 const u_int16_t __v = (v); \
358 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \
359 ((u_char *)(p))[1] = __v & 0xff; \
362 /* Internal definitions follow. Exposed for regress tests */
363 #ifdef SSHBUF_INTERNAL
366 * Return the allocation size of buf
368 size_t sshbuf_alloc(const struct sshbuf
*buf
);
371 * Increment the reference count of buf.
373 int sshbuf_set_parent(struct sshbuf
*child
, struct sshbuf
*parent
);
376 * Return the parent buffer of buf, or NULL if it has no parent.
378 const struct sshbuf
*sshbuf_parent(const struct sshbuf
*buf
);
381 * Return the reference count of buf
383 u_int
sshbuf_refcount(const struct sshbuf
*buf
);
385 # define SSHBUF_SIZE_INIT 256 /* Initial allocation */
386 # define SSHBUF_SIZE_INC 256 /* Preferred increment length */
387 # define SSHBUF_PACK_MIN 8192 /* Minimum packable offset */
389 /* # define SSHBUF_ABORT abort */
390 /* # define SSHBUF_DEBUG */
392 # ifndef SSHBUF_ABORT
393 # define SSHBUF_ABORT()
397 # define SSHBUF_TELL(what) do { \
398 printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \
399 __FILE__, __LINE__, __func__, what, \
400 buf->size, buf->alloc, buf->off, buf->max_size); \
403 # define SSHBUF_DBG(x) do { \
404 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \
410 # define SSHBUF_TELL(what)
411 # define SSHBUF_DBG(x)
413 #endif /* SSHBUF_INTERNAL */
415 #endif /* _SSHBUF_H */