1 /* $NetBSD: sshbuf.h,v 1.24 2026/09/21 21:31:00 christos Exp $ */ 2 /* $OpenBSD: sshbuf.h,v 1.36 2026/04/07 07:40:40 djm Exp $ */ 3 4 /* 5 * Copyright (c) 2011 Damien Miller 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #ifndef _SSHBUF_H 21 #define _SSHBUF_H 22 23 #include <sys/types.h> 24 #include <stdarg.h> 25 #include <stdio.h> 26 #include <stdint.h> 27 28 #ifdef WITH_OPENSSL 29 #include <openssl/bn.h> 30 #include <openssl/ec.h> 31 #include <openssl/ecdsa.h> 32 #include <openssl/evp.h> 33 #else /* OPENSSL */ 34 #define BIGNUM void 35 #define EC_KEY void 36 #define EC_GROUP void 37 #define EC_POINT void 38 #define EVP_PKEY void 39 #endif /* WITH_OPENSSL */ 40 41 #define SSHBUF_SIZE_MAX 0x10000000 /* Hard maximum size 256MB */ 42 #define SSHBUF_REFS_MAX 0x100000 /* Max child buffers */ 43 #define SSHBUF_MAX_BIGNUM (16384 / 8) /* Max bignum *bytes* */ 44 #define SSHBUF_MAX_ECPOINT ((528 * 2 / 8) + 1) /* Max EC point *bytes* */ 45 46 struct sshbuf; 47 48 /* 49 * Create a new sshbuf buffer. 50 * Returns pointer to buffer on success, or NULL on allocation failure. 51 */ 52 struct sshbuf *sshbuf_new(void); 53 54 /* 55 * Create a new, read-only sshbuf buffer from existing data. 56 * Returns pointer to buffer on success, or NULL on allocation failure. 57 */ 58 struct sshbuf *sshbuf_from(const void *blob, size_t len); 59 60 /* 61 * Create a new, read-only sshbuf buffer from the contents of an existing 62 * buffer. The contents of "buf" must not change in the lifetime of the 63 * resultant buffer. 64 * Returns pointer to buffer on success, or NULL on allocation failure. 65 */ 66 struct sshbuf *sshbuf_fromb(struct sshbuf *buf); 67 68 /* 69 * Create a new, read-only sshbuf buffer from the contents of a string in 70 * an existing buffer (the string is consumed in the process). 71 * The contents of "buf" must not change in the lifetime of the resultant 72 * buffer. 73 * On success, a pointer to the newly allocated buffer is placed in *bufp. 74 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 75 */ 76 int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp); 77 78 /* 79 * Clear and free buf 80 */ 81 void sshbuf_free(struct sshbuf *buf); 82 83 /* 84 * Reset buf, clearing its contents. NB. max_size is preserved. 85 */ 86 void sshbuf_reset(struct sshbuf *buf); 87 88 /* 89 * Return the maximum size of buf 90 */ 91 size_t sshbuf_max_size(const struct sshbuf *buf); 92 93 /* 94 * Set the maximum size of buf 95 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 96 */ 97 int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size); 98 99 /* 100 * Returns the length of data in buf 101 */ 102 size_t sshbuf_len(const struct sshbuf *buf); 103 104 /* 105 * Returns number of bytes left in buffer before hitting max_size. 106 */ 107 size_t sshbuf_avail(const struct sshbuf *buf); 108 109 /* 110 * Returns a read-only pointer to the start of the data in buf 111 */ 112 const u_char *sshbuf_ptr(const struct sshbuf *buf); 113 114 /* 115 * Returns a mutable pointer to the start of the data in buf, or 116 * NULL if the buffer is read-only. 117 */ 118 u_char *sshbuf_mutable_ptr(const struct sshbuf *buf); 119 120 /* 121 * Check whether a reservation of size len will succeed in buf 122 * Safer to use than direct comparisons again sshbuf_avail as it copes 123 * with unsigned overflows correctly. 124 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 125 */ 126 int sshbuf_check_reserve(const struct sshbuf *buf, size_t len); 127 128 /* 129 * Preallocates len additional bytes in buf. 130 * Useful for cases where the caller knows how many bytes will ultimately be 131 * required to avoid realloc in the buffer code. 132 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 133 */ 134 int sshbuf_allocate(struct sshbuf *buf, size_t len); 135 136 /* 137 * Reserve len bytes in buf. 138 * Returns 0 on success and a pointer to the first reserved byte via the 139 * optional dpp parameter or a negative SSH_ERR_* error code on failure. 140 */ 141 int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp); 142 143 /* 144 * Consume len bytes from the start of buf 145 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 146 */ 147 int sshbuf_consume(struct sshbuf *buf, size_t len); 148 149 /* 150 * Consume len bytes from the end of buf 151 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 152 */ 153 int sshbuf_consume_end(struct sshbuf *buf, size_t len); 154 155 /* 156 * Consume data from a parent buffer up to that of a child buffer (i.e. 157 * one created by sshbuf_fromb()). 158 * 159 * Intended to be used in a pattern like: 160 * 161 * b = sshbuf_fromb(parent); 162 * sshbuf_get_string(b, &foo, &foostr); 163 * sshbuf_get_u32(b, &bar); 164 * sshbuf_consume_upto_child(parent, b); 165 * 166 * After which, both "b" and "parent" will point to the same data. 167 * 168 * "child" must be a direct child of "buf" (i.e. neither an unrelated buffer 169 * nor a grandchild) which has consumed data past that of "buf". 170 */ 171 int sshbuf_consume_upto_child(struct sshbuf *buf, const struct sshbuf *child); 172 173 /* Extract or deposit some bytes */ 174 int sshbuf_get(struct sshbuf *buf, void *v, size_t len); 175 int sshbuf_put(struct sshbuf *buf, const void *v, size_t len); 176 int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v); 177 178 /* Append using a printf(3) format */ 179 int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...) 180 __attribute__((format(printf, 2, 3))); 181 int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap) 182 __printflike(2, 0); 183 184 /* Functions to extract or store big-endian words of various sizes */ 185 int sshbuf_get_u64(struct sshbuf *buf, uint64_t *valp); 186 int sshbuf_get_u32(struct sshbuf *buf, uint32_t *valp); 187 int sshbuf_get_u16(struct sshbuf *buf, uint16_t *valp); 188 int sshbuf_get_u8(struct sshbuf *buf, u_char *valp); 189 int sshbuf_put_u64(struct sshbuf *buf, uint64_t val); 190 int sshbuf_put_u32(struct sshbuf *buf, uint32_t val); 191 int sshbuf_put_u16(struct sshbuf *buf, uint16_t val); 192 int sshbuf_put_u8(struct sshbuf *buf, u_char val); 193 194 /* Functions to peek at the contents of a buffer without modifying it. */ 195 int sshbuf_peek_u64(const struct sshbuf *buf, size_t offset, 196 uint64_t *valp); 197 int sshbuf_peek_u32(const struct sshbuf *buf, size_t offset, 198 uint32_t *valp); 199 int sshbuf_peek_u16(const struct sshbuf *buf, size_t offset, 200 uint16_t *valp); 201 int sshbuf_peek_u8(const struct sshbuf *buf, size_t offset, 202 u_char *valp); 203 204 /* 205 * Functions to poke values into an existing buffer (e.g. a length header 206 * to a packet). The destination bytes must already exist in the buffer. 207 */ 208 int sshbuf_poke_u64(struct sshbuf *buf, size_t offset, uint64_t val); 209 int sshbuf_poke_u32(struct sshbuf *buf, size_t offset, uint32_t val); 210 int sshbuf_poke_u16(struct sshbuf *buf, size_t offset, uint16_t val); 211 int sshbuf_poke_u8(struct sshbuf *buf, size_t offset, u_char val); 212 int sshbuf_poke(struct sshbuf *buf, size_t offset, void *v, size_t len); 213 214 /* 215 * Functions to extract or store SSH wire encoded strings (u32 len || data) 216 * The "cstring" variants admit no \0 characters in the string contents. 217 * Caller must free *valp. 218 */ 219 int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp); 220 int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp); 221 int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v); 222 int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len); 223 int sshbuf_put_cstring(struct sshbuf *buf, const char *v); 224 int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v); 225 226 /* 227 * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to 228 * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the 229 * next sshbuf-modifying function call. Caller does not free. 230 */ 231 int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp, 232 size_t *lenp); 233 234 /* Skip past a string */ 235 #define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL) 236 237 /* Another variant: "peeks" into the buffer without modifying it */ 238 int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp, 239 size_t *lenp); 240 241 /* 242 * Functions to extract or store SSH wire encoded bignums and elliptic 243 * curve points. 244 */ 245 int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM **valp); 246 int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf, 247 const u_char **valp, size_t *lenp); 248 int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v); 249 int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len); 250 int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g); 251 int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v); 252 int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g); 253 int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v); 254 int sshbuf_put_ec_pkey(struct sshbuf *buf, EVP_PKEY *pkey); 255 256 /* Functions to extract or store various non-SSH wire encoded values */ 257 int sshbuf_get_nulterminated_string(struct sshbuf *buf, size_t maxlen, 258 char **valp, size_t *lenp); 259 260 /* Dump the contents of the buffer in a human-readable format */ 261 void sshbuf_dump(const struct sshbuf *buf, FILE *f); 262 263 /* Dump specified memory in a human-readable format */ 264 void sshbuf_dump_data(const void *s, size_t len, FILE *f); 265 266 /* Return the hexadecimal representation of the contents of the buffer */ 267 char *sshbuf_dtob16(const struct sshbuf *buf); 268 /* Make a sshbuf from a hex string */ 269 struct sshbuf *sshbuf_b16tod(const char *b16); 270 271 /* Encode the contents of the buffer as base64 */ 272 char *sshbuf_dtob64_string(const struct sshbuf *buf, int wrap); 273 int sshbuf_dtob64(const struct sshbuf *d, struct sshbuf *b64, int wrap); 274 /* RFC4648 "base64url" encoding variant */ 275 int sshbuf_dtourlb64(const struct sshbuf *d, struct sshbuf *b64, int wrap); 276 277 /* Decode base64 data and append it to the buffer */ 278 int sshbuf_b64tod(struct sshbuf *buf, const char *b64); 279 280 /* 281 * Tests whether the buffer contains the specified byte sequence at the 282 * specified offset. Returns 0 on successful match, or a ssherr.h code 283 * otherwise. SSH_ERR_INVALID_FORMAT indicates sufficient bytes were 284 * present but the buffer contents did not match those supplied. Zero- 285 * length comparisons are not allowed. 286 * 287 * If sufficient data is present to make a comparison, then it is 288 * performed with timing independent of the value of the data. If 289 * insufficient data is present then the comparison is not attempted at 290 * all. 291 */ 292 int sshbuf_cmp(const struct sshbuf *b, size_t offset, 293 const void *s, size_t len); 294 295 /* 296 * Test whether two buffers have identical contents. 297 * SSH_ERR_MESSAGE_INCOMPLETE indicates the buffers had differing size. 298 * SSH_ERR_INVALID_FORMAT indicates the buffers were the same size but 299 * had differing contents. 300 * Returns 0 on successful compare (comparing two empty buffers returns 0). 301 */ 302 int sshbuf_equals(const struct sshbuf *a, const struct sshbuf *b); 303 304 /* 305 * Searches the buffer for the specified string. Returns 0 on success 306 * and updates *offsetp with the offset of the first match, relative to 307 * the start of the buffer. Otherwise sshbuf_find will return a ssherr.h 308 * error code. SSH_ERR_INVALID_FORMAT indicates sufficient bytes were 309 * present in the buffer for a match to be possible but none was found. 310 * Searches for zero-length data are not allowed. 311 */ 312 int 313 sshbuf_find(const struct sshbuf *b, size_t start_offset, 314 const void *s, size_t len, size_t *offsetp); 315 316 /* 317 * Duplicate the contents of a buffer to a string (caller to free). 318 * Returns NULL on buffer error, or if the buffer contains a premature 319 * nul character. 320 */ 321 char *sshbuf_dup_string(struct sshbuf *buf); 322 323 /* 324 * Fill a buffer from a file descriptor or filename. Both allocate the 325 * buffer for the caller. 326 */ 327 int sshbuf_load_fd(int, struct sshbuf **) 328 __attribute__((__nonnull__ (2))); 329 int sshbuf_load_file(const char *, struct sshbuf **) 330 __attribute__((__nonnull__ (2))); 331 332 /* 333 * Write a buffer to a path, creating/truncating as needed (mode 0644, 334 * subject to umask). The buffer contents are not modified. 335 */ 336 int sshbuf_write_file(const char *path, struct sshbuf *buf) 337 __attribute__((__nonnull__ (2))); 338 339 /* Read up to maxlen bytes from a fd directly to a buffer */ 340 int sshbuf_read(int, struct sshbuf *, size_t, size_t *) 341 __attribute__((__nonnull__ (2))); 342 343 /* Macros for decoding/encoding integers */ 344 #define PEEK_U64(p) \ 345 (((uint64_t)(((const u_char *)(p))[0]) << 56) | \ 346 ((uint64_t)(((const u_char *)(p))[1]) << 48) | \ 347 ((uint64_t)(((const u_char *)(p))[2]) << 40) | \ 348 ((uint64_t)(((const u_char *)(p))[3]) << 32) | \ 349 ((uint64_t)(((const u_char *)(p))[4]) << 24) | \ 350 ((uint64_t)(((const u_char *)(p))[5]) << 16) | \ 351 ((uint64_t)(((const u_char *)(p))[6]) << 8) | \ 352 (uint64_t)(((const u_char *)(p))[7])) 353 #define PEEK_U32(p) \ 354 (((uint32_t)(((const u_char *)(p))[0]) << 24) | \ 355 ((uint32_t)(((const u_char *)(p))[1]) << 16) | \ 356 ((uint32_t)(((const u_char *)(p))[2]) << 8) | \ 357 (uint32_t)(((const u_char *)(p))[3])) 358 #define PEEK_U16(p) \ 359 (((uint16_t)(((const u_char *)(p))[0]) << 8) | \ 360 (uint16_t)(((const u_char *)(p))[1])) 361 362 #define POKE_U64(p, v) \ 363 do { \ 364 const uint64_t __v = (v); \ 365 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \ 366 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \ 367 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \ 368 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \ 369 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \ 370 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \ 371 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \ 372 ((u_char *)(p))[7] = __v & 0xff; \ 373 } while (0) 374 #define POKE_U32(p, v) \ 375 do { \ 376 const uint32_t __v = (v); \ 377 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \ 378 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \ 379 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \ 380 ((u_char *)(p))[3] = __v & 0xff; \ 381 } while (0) 382 #define POKE_U16(p, v) \ 383 do { \ 384 const uint16_t __v = (v); \ 385 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \ 386 ((u_char *)(p))[1] = __v & 0xff; \ 387 } while (0) 388 389 /* Internal definitions follow. Exposed for regress tests */ 390 #ifdef SSHBUF_INTERNAL 391 392 /* 393 * Return the allocation size of buf 394 */ 395 size_t sshbuf_alloc(const struct sshbuf *buf); 396 397 /* 398 * Increment the reference count of buf. 399 */ 400 int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent); 401 402 /* 403 * Return the parent buffer of buf, or NULL if it has no parent. 404 */ 405 const struct sshbuf *sshbuf_parent(const struct sshbuf *buf); 406 407 /* 408 * Return the reference count of buf 409 */ 410 u_int sshbuf_refcount(const struct sshbuf *buf); 411 412 # define SSHBUF_SIZE_INIT 256 /* Initial allocation */ 413 # define SSHBUF_SIZE_INC 256 /* Preferred increment length */ 414 # define SSHBUF_PACK_MIN 8192 /* Minimum packable offset */ 415 416 /* # define SSHBUF_ABORT abort */ 417 /* # define SSHBUF_DEBUG */ 418 419 # ifndef SSHBUF_ABORT 420 # define SSHBUF_ABORT() 421 # endif 422 423 # ifdef SSHBUF_DEBUG 424 # define SSHBUF_DBG(x) do { \ 425 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \ 426 printf x; \ 427 printf("\n"); \ 428 fflush(stdout); \ 429 } while (0) 430 # else 431 # define SSHBUF_DBG(x) 432 # endif 433 #endif /* SSHBUF_INTERNAL */ 434 435 #endif /* _SSHBUF_H */ 436
Indexes created Fri Oct 09 00:27:48 UTC 2026