1 /* $NetBSD: sshbuf.h,v 1.9 2018/04/06 18:59:00 christos Exp $ */ 2 /* $OpenBSD: sshbuf.h,v 1.9 2017/09/12 06:32:07 djm Exp $ */ 3 /* 4 * Copyright (c) 2011 Damien Miller 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #ifndef _SSHBUF_H 20 #define _SSHBUF_H 21 22 #include <sys/types.h> 23 #include <stdarg.h> 24 #include <stdio.h> 25 #include <openssl/bn.h> 26 #include <openssl/ec.h> 27 28 #define SSHBUF_SIZE_MAX 0x8000000 /* Hard maximum size */ 29 #define SSHBUF_REFS_MAX 0x100000 /* Max child buffers */ 30 #define SSHBUF_MAX_BIGNUM (16384 / 8) /* Max bignum *bytes* */ 31 #define SSHBUF_MAX_ECPOINT ((528 * 2 / 8) + 1) /* Max EC point *bytes* */ 32 33 /* 34 * NB. do not depend on the internals of this. It will be made opaque 35 * one day. 36 */ 37 struct sshbuf { 38 u_char *d; /* Data */ 39 const u_char *cd; /* Const data */ 40 size_t off; /* First available byte is buf->d + buf->off */ 41 size_t size; /* Last byte is buf->d + buf->size - 1 */ 42 size_t max_size; /* Maximum size of buffer */ 43 size_t alloc; /* Total bytes allocated to buf->d */ 44 int readonly; /* Refers to external, const data */ 45 int dont_free; /* Kludge to support sshbuf_init */ 46 u_int refcount; /* Tracks self and number of child buffers */ 47 struct sshbuf *parent; /* If child, pointer to parent */ 48 }; 49 50 #ifndef SSHBUF_NO_DEPREACTED 51 /* 52 * NB. Please do not use sshbuf_init() in new code. Please use sshbuf_new() 53 * instead. sshbuf_init() is deprectated and will go away soon (it is 54 * only included to allow compat with buffer_* in OpenSSH) 55 */ 56 void sshbuf_init(struct sshbuf *buf); 57 #endif 58 59 /* 60 * Create a new sshbuf buffer. 61 * Returns pointer to buffer on success, or NULL on allocation failure. 62 */ 63 struct sshbuf *sshbuf_new(void); 64 65 /* 66 * Create a new, read-only sshbuf buffer from existing data. 67 * Returns pointer to buffer on success, or NULL on allocation failure. 68 */ 69 struct sshbuf *sshbuf_from(const void *blob, size_t len); 70 71 /* 72 * Create a new, read-only sshbuf buffer from the contents of an existing 73 * buffer. The contents of "buf" must not change in the lifetime of the 74 * resultant buffer. 75 * Returns pointer to buffer on success, or NULL on allocation failure. 76 */ 77 struct sshbuf *sshbuf_fromb(struct sshbuf *buf); 78 79 /* 80 * Create a new, read-only sshbuf buffer from the contents of a string in 81 * an existing buffer (the string is consumed in the process). 82 * The contents of "buf" must not change in the lifetime of the resultant 83 * buffer. 84 * Returns pointer to buffer on success, or NULL on allocation failure. 85 */ 86 int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp); 87 88 /* 89 * Clear and free buf 90 */ 91 void sshbuf_free(struct sshbuf *buf); 92 93 /* 94 * Reset buf, clearing its contents. NB. max_size is preserved. 95 */ 96 void sshbuf_reset(struct sshbuf *buf); 97 98 /* 99 * Return the maximum size of buf 100 */ 101 size_t sshbuf_max_size(const struct sshbuf *buf); 102 103 /* 104 * Set the maximum size of buf 105 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 106 */ 107 int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size); 108 109 /* 110 * Returns the length of data in buf 111 */ 112 size_t sshbuf_len(const struct sshbuf *buf); 113 114 /* 115 * Returns number of bytes left in buffer before hitting max_size. 116 */ 117 size_t sshbuf_avail(const struct sshbuf *buf); 118 119 /* 120 * Returns a read-only pointer to the start of the data in buf 121 */ 122 const u_char *sshbuf_ptr(const struct sshbuf *buf); 123 124 /* 125 * Returns a mutable pointer to the start of the data in buf, or 126 * NULL if the buffer is read-only. 127 */ 128 u_char *sshbuf_mutable_ptr(const struct sshbuf *buf); 129 130 /* 131 * Check whether a reservation of size len will succeed in buf 132 * Safer to use than direct comparisons again sshbuf_avail as it copes 133 * with unsigned overflows correctly. 134 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 135 */ 136 int sshbuf_check_reserve(const struct sshbuf *buf, size_t len); 137 138 /* 139 * Preallocates len additional bytes in buf. 140 * Useful for cases where the caller knows how many bytes will ultimately be 141 * required to avoid realloc in the buffer code. 142 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 143 */ 144 int sshbuf_allocate(struct sshbuf *buf, size_t len); 145 146 /* 147 * Reserve len bytes in buf. 148 * Returns 0 on success and a pointer to the first reserved byte via the 149 * optional dpp parameter or a negative * SSH_ERR_* error code on failure. 150 */ 151 int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp); 152 153 /* 154 * Consume len bytes from the start of buf 155 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 156 */ 157 int sshbuf_consume(struct sshbuf *buf, size_t len); 158 159 /* 160 * Consume len bytes from the end of buf 161 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 162 */ 163 int sshbuf_consume_end(struct sshbuf *buf, size_t len); 164 165 /* Extract or deposit some bytes */ 166 int sshbuf_get(struct sshbuf *buf, void *v, size_t len); 167 int sshbuf_put(struct sshbuf *buf, const void *v, size_t len); 168 int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v); 169 170 /* Append using a printf(3) format */ 171 int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...) 172 __attribute__((format(printf, 2, 3))); 173 int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap) 174 __printflike(2, 0); 175 176 /* Functions to extract or store big-endian words of various sizes */ 177 int sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp); 178 int sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp); 179 int sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp); 180 int sshbuf_get_u8(struct sshbuf *buf, u_char *valp); 181 int sshbuf_put_u64(struct sshbuf *buf, u_int64_t val); 182 int sshbuf_put_u32(struct sshbuf *buf, u_int32_t val); 183 int sshbuf_put_u16(struct sshbuf *buf, u_int16_t val); 184 int sshbuf_put_u8(struct sshbuf *buf, u_char val); 185 186 /* 187 * Functions to extract or store SSH wire encoded strings (u32 len || data) 188 * The "cstring" variants admit no \0 characters in the string contents. 189 * Caller must free *valp. 190 */ 191 int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp); 192 int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp); 193 int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v); 194 int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len); 195 int sshbuf_put_cstring(struct sshbuf *buf, const char *v); 196 int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v); 197 198 /* 199 * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to 200 * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the 201 * next sshbuf-modifying function call. Caller does not free. 202 */ 203 int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp, 204 size_t *lenp); 205 206 /* Skip past a string */ 207 #define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL) 208 209 /* Another variant: "peeks" into the buffer without modifying it */ 210 int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp, 211 size_t *lenp); 212 /* XXX peek_u8 / peek_u32 */ 213 214 /* 215 * Functions to extract or store SSH wire encoded bignums and elliptic 216 * curve points. 217 */ 218 int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v); 219 int sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v); 220 int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf, 221 const u_char **valp, size_t *lenp); 222 int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v); 223 int sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v); 224 int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len); 225 int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g); 226 int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v); 227 int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g); 228 int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v); 229 230 /* Dump the contents of the buffer in a human-readable format */ 231 void sshbuf_dump(struct sshbuf *buf, FILE *f); 232 233 /* Dump specified memory in a human-readable format */ 234 void sshbuf_dump_data(const void *s, size_t len, FILE *f); 235 236 /* Return the hexadecimal representation of the contents of the buffer */ 237 char *sshbuf_dtob16(struct sshbuf *buf); 238 239 /* Encode the contents of the buffer as base64 */ 240 char *sshbuf_dtob64(struct sshbuf *buf); 241 242 /* Decode base64 data and append it to the buffer */ 243 int sshbuf_b64tod(struct sshbuf *buf, const char *b64); 244 245 /* 246 * Duplicate the contents of a buffer to a string (caller to free). 247 * Returns NULL on buffer error, or if the buffer contains a premature 248 * nul character. 249 */ 250 char *sshbuf_dup_string(struct sshbuf *buf); 251 252 /* Macros for decoding/encoding integers */ 253 #define PEEK_U64(p) \ 254 (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \ 255 ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \ 256 ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \ 257 ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \ 258 ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \ 259 ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \ 260 ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \ 261 (u_int64_t)(((const u_char *)(p))[7])) 262 #define PEEK_U32(p) \ 263 (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \ 264 ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \ 265 ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \ 266 (u_int32_t)(((const u_char *)(p))[3])) 267 #define PEEK_U16(p) \ 268 (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \ 269 (u_int16_t)(((const u_char *)(p))[1])) 270 271 #define POKE_U64(p, v) \ 272 do { \ 273 const u_int64_t __v = (v); \ 274 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \ 275 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \ 276 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \ 277 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \ 278 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \ 279 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \ 280 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \ 281 ((u_char *)(p))[7] = __v & 0xff; \ 282 } while (0) 283 #define POKE_U32(p, v) \ 284 do { \ 285 const u_int32_t __v = (v); \ 286 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \ 287 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \ 288 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \ 289 ((u_char *)(p))[3] = __v & 0xff; \ 290 } while (0) 291 #define POKE_U16(p, v) \ 292 do { \ 293 const u_int16_t __v = (v); \ 294 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \ 295 ((u_char *)(p))[1] = __v & 0xff; \ 296 } while (0) 297 298 /* Internal definitions follow. Exposed for regress tests */ 299 #ifdef SSHBUF_INTERNAL 300 301 /* 302 * Return the allocation size of buf 303 */ 304 size_t sshbuf_alloc(const struct sshbuf *buf); 305 306 /* 307 * Increment the reference count of buf. 308 */ 309 int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent); 310 311 /* 312 * Return the parent buffer of buf, or NULL if it has no parent. 313 */ 314 const struct sshbuf *sshbuf_parent(const struct sshbuf *buf); 315 316 /* 317 * Return the reference count of buf 318 */ 319 u_int sshbuf_refcount(const struct sshbuf *buf); 320 321 # define SSHBUF_SIZE_INIT 256 /* Initial allocation */ 322 # define SSHBUF_SIZE_INC 256 /* Preferred increment length */ 323 # define SSHBUF_PACK_MIN 8192 /* Minimim packable offset */ 324 325 /* # define SSHBUF_ABORT abort */ 326 /* # define SSHBUF_DEBUG */ 327 328 # ifndef SSHBUF_ABORT 329 # define SSHBUF_ABORT() 330 # endif 331 332 # ifdef SSHBUF_DEBUG 333 # define SSHBUF_TELL(what) do { \ 334 printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \ 335 __FILE__, __LINE__, __func__, what, \ 336 buf->size, buf->alloc, buf->off, buf->max_size); \ 337 fflush(stdout); \ 338 } while (0) 339 # define SSHBUF_DBG(x) do { \ 340 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \ 341 printf x; \ 342 printf("\n"); \ 343 fflush(stdout); \ 344 } while (0) 345 # else 346 # define SSHBUF_TELL(what) 347 # define SSHBUF_DBG(x) 348 # endif 349 #endif /* SSHBUF_INTERNAL */ 350 351 #endif /* _SSHBUF_H */ 352