1 /* $OpenBSD: sshbuf.h,v 1.11 2018/07/09 21:56:06 markus 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>
26 # include <openssl/bn.h>
27 # ifdef OPENSSL_HAS_ECC
28 # include <openssl/ec.h>
29 # endif /* OPENSSL_HAS_ECC */
30 #endif /* WITH_OPENSSL */
32 #define SSHBUF_SIZE_MAX 0x8000000 /* Hard maximum size */
33 #define SSHBUF_REFS_MAX 0x100000 /* Max child buffers */
34 #define SSHBUF_MAX_BIGNUM (16384 / 8) /* Max bignum *bytes* */
35 #define SSHBUF_MAX_ECPOINT ((528 * 2 / 8) + 1) /* Max EC point *bytes* */
38 * NB. do not depend on the internals of this. It will be made opaque
43 const u_char *cd; /* Const data */
44 size_t off; /* First available byte is buf->d + buf->off */
45 size_t size; /* Last byte is buf->d + buf->size - 1 */
46 size_t max_size; /* Maximum size of buffer */
47 size_t alloc; /* Total bytes allocated to buf->d */
48 int readonly; /* Refers to external, const data */
49 int dont_free; /* Kludge to support sshbuf_init */
50 u_int refcount; /* Tracks self and number of child buffers */
51 struct sshbuf *parent; /* If child, pointer to parent */
55 * Create a new sshbuf buffer.
56 * Returns pointer to buffer on success, or NULL on allocation failure.
58 struct sshbuf *sshbuf_new(void);
61 * Create a new, read-only sshbuf buffer from existing data.
62 * Returns pointer to buffer on success, or NULL on allocation failure.
64 struct sshbuf *sshbuf_from(const void *blob, size_t len);
67 * Create a new, read-only sshbuf buffer from the contents of an existing
68 * buffer. The contents of "buf" must not change in the lifetime of the
70 * Returns pointer to buffer on success, or NULL on allocation failure.
72 struct sshbuf *sshbuf_fromb(struct sshbuf *buf);
75 * Create a new, read-only sshbuf buffer from the contents of a string in
76 * an existing buffer (the string is consumed in the process).
77 * The contents of "buf" must not change in the lifetime of the resultant
79 * Returns pointer to buffer on success, or NULL on allocation failure.
81 int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp);
86 void sshbuf_free(struct sshbuf *buf);
89 * Reset buf, clearing its contents. NB. max_size is preserved.
91 void sshbuf_reset(struct sshbuf *buf);
94 * Return the maximum size of buf
96 size_t sshbuf_max_size(const struct sshbuf *buf);
99 * Set the maximum size of buf
100 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
102 int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size);
105 * Returns the length of data in buf
107 size_t sshbuf_len(const struct sshbuf *buf);
110 * Returns number of bytes left in buffer before hitting max_size.
112 size_t sshbuf_avail(const struct sshbuf *buf);
115 * Returns a read-only pointer to the start of the data in buf
117 const u_char *sshbuf_ptr(const struct sshbuf *buf);
120 * Returns a mutable pointer to the start of the data in buf, or
121 * NULL if the buffer is read-only.
123 u_char *sshbuf_mutable_ptr(const struct sshbuf *buf);
126 * Check whether a reservation of size len will succeed in buf
127 * Safer to use than direct comparisons again sshbuf_avail as it copes
128 * with unsigned overflows correctly.
129 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
131 int sshbuf_check_reserve(const struct sshbuf *buf, size_t len);
134 * Preallocates len additional bytes in buf.
135 * Useful for cases where the caller knows how many bytes will ultimately be
136 * required to avoid realloc in the buffer code.
137 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
139 int sshbuf_allocate(struct sshbuf *buf, size_t len);
142 * Reserve len bytes in buf.
143 * Returns 0 on success and a pointer to the first reserved byte via the
144 * optional dpp parameter or a negative * SSH_ERR_* error code on failure.
146 int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp);
149 * Consume len bytes from the start of buf
150 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
152 int sshbuf_consume(struct sshbuf *buf, size_t len);
155 * Consume len bytes from the end of buf
156 * Returns 0 on success, or a negative SSH_ERR_* error code on failure.
158 int sshbuf_consume_end(struct sshbuf *buf, size_t len);
160 /* Extract or deposit some bytes */
161 int sshbuf_get(struct sshbuf *buf, void *v, size_t len);
162 int sshbuf_put(struct sshbuf *buf, const void *v, size_t len);
163 int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v);
165 /* Append using a printf(3) format */
166 int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...)
167 __attribute__((format(printf, 2, 3)));
168 int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap);
170 /* Functions to extract or store big-endian words of various sizes */
171 int sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp);
172 int sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp);
173 int sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp);
174 int sshbuf_get_u8(struct sshbuf *buf, u_char *valp);
175 int sshbuf_put_u64(struct sshbuf *buf, u_int64_t val);
176 int sshbuf_put_u32(struct sshbuf *buf, u_int32_t val);
177 int sshbuf_put_u16(struct sshbuf *buf, u_int16_t val);
178 int sshbuf_put_u8(struct sshbuf *buf, u_char val);
181 * Functions to extract or store SSH wire encoded strings (u32 len || data)
182 * The "cstring" variants admit no \0 characters in the string contents.
183 * Caller must free *valp.
185 int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp);
186 int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp);
187 int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v);
188 int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len);
189 int sshbuf_put_cstring(struct sshbuf *buf, const char *v);
190 int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v);
193 * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to
194 * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the
195 * next sshbuf-modifying function call. Caller does not free.
197 int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp,
200 /* Skip past a string */
201 #define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL)
203 /* Another variant: "peeks" into the buffer without modifying it */
204 int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp,
206 /* XXX peek_u8 / peek_u32 */
209 * Functions to extract or store SSH wire encoded bignums and elliptic
212 int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len);
213 int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf,
214 const u_char **valp, size_t *lenp);
216 int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v);
217 int sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v);
218 int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v);
219 int sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v);
220 # ifdef OPENSSL_HAS_ECC
221 int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g);
222 int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v);
223 int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g);
224 int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v);
225 # endif /* OPENSSL_HAS_ECC */
226 #endif /* WITH_OPENSSL */
228 /* Dump the contents of the buffer in a human-readable format */
229 void sshbuf_dump(struct sshbuf *buf, FILE *f);
231 /* Dump specified memory in a human-readable format */
232 void sshbuf_dump_data(const void *s, size_t len, FILE *f);
234 /* Return the hexadecimal representation of the contents of the buffer */
235 char *sshbuf_dtob16(struct sshbuf *buf);
237 /* Encode the contents of the buffer as base64 */
238 char *sshbuf_dtob64(struct sshbuf *buf);
240 /* Decode base64 data and append it to the buffer */
241 int sshbuf_b64tod(struct sshbuf *buf, const char *b64);
244 * Duplicate the contents of a buffer to a string (caller to free).
245 * Returns NULL on buffer error, or if the buffer contains a premature
248 char *sshbuf_dup_string(struct sshbuf *buf);
253 int sshbuf_put_passwd(struct sshbuf *buf, const struct passwd *pwent);
258 struct passwd *sshbuf_get_passwd(struct sshbuf *buf);
261 * free struct passwd obtained from sshbuf_get_passwd.
263 void sshbuf_free_passwd(struct passwd *pwent);
265 /* Macros for decoding/encoding integers */
266 #define PEEK_U64(p) \
267 (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \
268 ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \
269 ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \
270 ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \
271 ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \
272 ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \
273 ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \
274 (u_int64_t)(((const u_char *)(p))[7]))
275 #define PEEK_U32(p) \
276 (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \
277 ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \
278 ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \
279 (u_int32_t)(((const u_char *)(p))[3]))
280 #define PEEK_U16(p) \
281 (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \
282 (u_int16_t)(((const u_char *)(p))[1]))
284 #define POKE_U64(p, v) \
286 const u_int64_t __v = (v); \
287 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \
288 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \
289 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \
290 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \
291 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \
292 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \
293 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \
294 ((u_char *)(p))[7] = __v & 0xff; \
296 #define POKE_U32(p, v) \
298 const u_int32_t __v = (v); \
299 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \
300 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \
301 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \
302 ((u_char *)(p))[3] = __v & 0xff; \
304 #define POKE_U16(p, v) \
306 const u_int16_t __v = (v); \
307 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \
308 ((u_char *)(p))[1] = __v & 0xff; \
311 /* Internal definitions follow. Exposed for regress tests */
312 #ifdef SSHBUF_INTERNAL
315 * Return the allocation size of buf
317 size_t sshbuf_alloc(const struct sshbuf *buf);
320 * Increment the reference count of buf.
322 int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent);
325 * Return the parent buffer of buf, or NULL if it has no parent.
327 const struct sshbuf *sshbuf_parent(const struct sshbuf *buf);
330 * Return the reference count of buf
332 u_int sshbuf_refcount(const struct sshbuf *buf);
334 # define SSHBUF_SIZE_INIT 256 /* Initial allocation */
335 # define SSHBUF_SIZE_INC 256 /* Preferred increment length */
336 # define SSHBUF_PACK_MIN 8192 /* Minimim packable offset */
338 /* # define SSHBUF_ABORT abort */
339 /* # define SSHBUF_DEBUG */
341 # ifndef SSHBUF_ABORT
342 # define SSHBUF_ABORT()
346 # define SSHBUF_TELL(what) do { \
347 printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \
348 __FILE__, __LINE__, __func__, what, \
349 buf->size, buf->alloc, buf->off, buf->max_size); \
352 # define SSHBUF_DBG(x) do { \
353 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \
359 # define SSHBUF_TELL(what)
360 # define SSHBUF_DBG(x)
362 #endif /* SSHBUF_INTERNAL */
364 #endif /* _SSHBUF_H */