1 /* $OpenBSD: sshbuf.h,v 1.7 2016/05/02 08:49:03 djm Exp $ */ 2 /* 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> 24 #include <openssl/bn.h> 25 #include <openssl/ec.h> 26 27 #define SSHBUF_SIZE_MAX 0x8000000 /* Hard maximum size */ 28 #define SSHBUF_REFS_MAX 0x100000 /* Max child buffers */ 29 #define SSHBUF_MAX_BIGNUM (16384 / 8) /* Max bignum *bytes* */ 30 #define SSHBUF_MAX_ECPOINT ((528 * 2 / 8) + 1) /* Max EC point *bytes* */ 31 32 /* 33 * NB. do not depend on the internals of this. It will be made opaque 34 * one day. 35 */ 36 struct sshbuf { 37 u_char *d; /* Data */ 38 const u_char *cd; /* Const data */ 39 size_t off; /* First available byte is buf->d + buf->off */ 40 size_t size; /* Last byte is buf->d + buf->size - 1 */ 41 size_t max_size; /* Maximum size of buffer */ 42 size_t alloc; /* Total bytes allocated to buf->d */ 43 int readonly; /* Refers to external, const data */ 44 int dont_free; /* Kludge to support sshbuf_init */ 45 u_int refcount; /* Tracks self and number of child buffers */ 46 struct sshbuf *parent; /* If child, pointer to parent */ 47 }; 48 49 #ifndef SSHBUF_NO_DEPREACTED 50 /* 51 * NB. Please do not use sshbuf_init() in new code. Please use sshbuf_new() 52 * instead. sshbuf_init() is deprectated and will go away soon (it is 53 * only included to allow compat with buffer_* in OpenSSH) 54 */ 55 void sshbuf_init(struct sshbuf *buf); 56 #endif 57 58 /* 59 * Create a new sshbuf buffer. 60 * Returns pointer to buffer on success, or NULL on allocation failure. 61 */ 62 struct sshbuf *sshbuf_new(void); 63 64 /* 65 * Create a new, read-only sshbuf buffer from existing data. 66 * Returns pointer to buffer on success, or NULL on allocation failure. 67 */ 68 struct sshbuf *sshbuf_from(const void *blob, size_t len); 69 70 /* 71 * Create a new, read-only sshbuf buffer from the contents of an existing 72 * buffer. The contents of "buf" must not change in the lifetime of the 73 * resultant buffer. 74 * Returns pointer to buffer on success, or NULL on allocation failure. 75 */ 76 struct sshbuf *sshbuf_fromb(struct sshbuf *buf); 77 78 /* 79 * Create a new, read-only sshbuf buffer from the contents of a string in 80 * an existing buffer (the string is consumed in the process). 81 * The contents of "buf" must not change in the lifetime of the resultant 82 * buffer. 83 * Returns pointer to buffer on success, or NULL on allocation failure. 84 */ 85 int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp); 86 87 /* 88 * Clear and free buf 89 */ 90 void sshbuf_free(struct sshbuf *buf); 91 92 /* 93 * Reset buf, clearing its contents. NB. max_size is preserved. 94 */ 95 void sshbuf_reset(struct sshbuf *buf); 96 97 /* 98 * Return the maximum size of buf 99 */ 100 size_t sshbuf_max_size(const struct sshbuf *buf); 101 102 /* 103 * Set the maximum size of buf 104 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 105 */ 106 int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size); 107 108 /* 109 * Returns the length of data in buf 110 */ 111 size_t sshbuf_len(const struct sshbuf *buf); 112 113 /* 114 * Returns number of bytes left in buffer before hitting max_size. 115 */ 116 size_t sshbuf_avail(const struct sshbuf *buf); 117 118 /* 119 * Returns a read-only pointer to the start of the data in buf 120 */ 121 const u_char *sshbuf_ptr(const struct sshbuf *buf); 122 123 /* 124 * Returns a mutable pointer to the start of the data in buf, or 125 * NULL if the buffer is read-only. 126 */ 127 u_char *sshbuf_mutable_ptr(const struct sshbuf *buf); 128 129 /* 130 * Check whether a reservation of size len will succeed in buf 131 * Safer to use than direct comparisons again sshbuf_avail as it copes 132 * with unsigned overflows correctly. 133 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 134 */ 135 int sshbuf_check_reserve(const struct sshbuf *buf, size_t len); 136 137 /* 138 * Reserve len bytes in buf. 139 * Returns 0 on success and a pointer to the first reserved byte via the 140 * optional dpp parameter or a negative * SSH_ERR_* error code on failure. 141 */ 142 int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp); 143 144 /* 145 * Consume len bytes from the start of buf 146 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 147 */ 148 int sshbuf_consume(struct sshbuf *buf, size_t len); 149 150 /* 151 * Consume len bytes from the end of buf 152 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 153 */ 154 int sshbuf_consume_end(struct sshbuf *buf, size_t len); 155 156 /* Extract or deposit some bytes */ 157 int sshbuf_get(struct sshbuf *buf, void *v, size_t len); 158 int sshbuf_put(struct sshbuf *buf, const void *v, size_t len); 159 int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v); 160 161 /* Append using a printf(3) format */ 162 int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...) 163 __attribute__((format(printf, 2, 3))); 164 int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap); 165 166 /* Functions to extract or store big-endian words of various sizes */ 167 int sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp); 168 int sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp); 169 int sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp); 170 int sshbuf_get_u8(struct sshbuf *buf, u_char *valp); 171 int sshbuf_put_u64(struct sshbuf *buf, u_int64_t val); 172 int sshbuf_put_u32(struct sshbuf *buf, u_int32_t val); 173 int sshbuf_put_u16(struct sshbuf *buf, u_int16_t val); 174 int sshbuf_put_u8(struct sshbuf *buf, u_char val); 175 176 /* 177 * Functions to extract or store SSH wire encoded strings (u32 len || data) 178 * The "cstring" variants admit no \0 characters in the string contents. 179 * Caller must free *valp. 180 */ 181 int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp); 182 int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp); 183 int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v); 184 int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len); 185 int sshbuf_put_cstring(struct sshbuf *buf, const char *v); 186 int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v); 187 188 /* 189 * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to 190 * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the 191 * next sshbuf-modifying function call. Caller does not free. 192 */ 193 int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp, 194 size_t *lenp); 195 196 /* Skip past a string */ 197 #define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL) 198 199 /* Another variant: "peeks" into the buffer without modifying it */ 200 int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp, 201 size_t *lenp); 202 203 /* 204 * Functions to extract or store SSH wire encoded bignums and elliptic 205 * curve points. 206 */ 207 int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v); 208 int sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v); 209 int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf, 210 const u_char **valp, size_t *lenp); 211 int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v); 212 int sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v); 213 int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len); 214 int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g); 215 int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v); 216 int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g); 217 int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v); 218 219 /* Dump the contents of the buffer in a human-readable format */ 220 void sshbuf_dump(struct sshbuf *buf, FILE *f); 221 222 /* Dump specified memory in a human-readable format */ 223 void sshbuf_dump_data(const void *s, size_t len, FILE *f); 224 225 /* Return the hexadecimal representation of the contents of the buffer */ 226 char *sshbuf_dtob16(struct sshbuf *buf); 227 228 /* Encode the contents of the buffer as base64 */ 229 char *sshbuf_dtob64(struct sshbuf *buf); 230 231 /* Decode base64 data and append it to the buffer */ 232 int sshbuf_b64tod(struct sshbuf *buf, const char *b64); 233 234 /* 235 * Duplicate the contents of a buffer to a string (caller to free). 236 * Returns NULL on buffer error, or if the buffer contains a premature 237 * nul character. 238 */ 239 char *sshbuf_dup_string(struct sshbuf *buf); 240 241 /* Macros for decoding/encoding integers */ 242 #define PEEK_U64(p) \ 243 (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \ 244 ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \ 245 ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \ 246 ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \ 247 ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \ 248 ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \ 249 ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \ 250 (u_int64_t)(((const u_char *)(p))[7])) 251 #define PEEK_U32(p) \ 252 (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \ 253 ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \ 254 ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \ 255 (u_int32_t)(((const u_char *)(p))[3])) 256 #define PEEK_U16(p) \ 257 (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \ 258 (u_int16_t)(((const u_char *)(p))[1])) 259 260 #define POKE_U64(p, v) \ 261 do { \ 262 const u_int64_t __v = (v); \ 263 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \ 264 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \ 265 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \ 266 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \ 267 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \ 268 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \ 269 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \ 270 ((u_char *)(p))[7] = __v & 0xff; \ 271 } while (0) 272 #define POKE_U32(p, v) \ 273 do { \ 274 const u_int32_t __v = (v); \ 275 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \ 276 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \ 277 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \ 278 ((u_char *)(p))[3] = __v & 0xff; \ 279 } while (0) 280 #define POKE_U16(p, v) \ 281 do { \ 282 const u_int16_t __v = (v); \ 283 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \ 284 ((u_char *)(p))[1] = __v & 0xff; \ 285 } while (0) 286 287 /* Internal definitions follow. Exposed for regress tests */ 288 #ifdef SSHBUF_INTERNAL 289 290 /* 291 * Return the allocation size of buf 292 */ 293 size_t sshbuf_alloc(const struct sshbuf *buf); 294 295 /* 296 * Increment the reference count of buf. 297 */ 298 int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent); 299 300 /* 301 * Return the parent buffer of buf, or NULL if it has no parent. 302 */ 303 const struct sshbuf *sshbuf_parent(const struct sshbuf *buf); 304 305 /* 306 * Return the reference count of buf 307 */ 308 u_int sshbuf_refcount(const struct sshbuf *buf); 309 310 # define SSHBUF_SIZE_INIT 256 /* Initial allocation */ 311 # define SSHBUF_SIZE_INC 256 /* Preferred increment length */ 312 # define SSHBUF_PACK_MIN 8192 /* Minimim packable offset */ 313 314 /* # define SSHBUF_ABORT abort */ 315 /* # define SSHBUF_DEBUG */ 316 317 # ifndef SSHBUF_ABORT 318 # define SSHBUF_ABORT() 319 # endif 320 321 # ifdef SSHBUF_DEBUG 322 # define SSHBUF_TELL(what) do { \ 323 printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \ 324 __FILE__, __LINE__, __func__, what, \ 325 buf->size, buf->alloc, buf->off, buf->max_size); \ 326 fflush(stdout); \ 327 } while (0) 328 # define SSHBUF_DBG(x) do { \ 329 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \ 330 printf x; \ 331 printf("\n"); \ 332 fflush(stdout); \ 333 } while (0) 334 # else 335 # define SSHBUF_TELL(what) 336 # define SSHBUF_DBG(x) 337 # endif 338 #endif /* SSHBUF_INTERNAL */ 339 340 #endif /* _SSHBUF_H */ 341