sshbuf.h revision 323120
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#ifdef WITH_OPENSSL 25# include <openssl/bn.h> 26# ifdef OPENSSL_HAS_ECC 27# include <openssl/ec.h> 28# endif /* OPENSSL_HAS_ECC */ 29#endif /* WITH_OPENSSL */ 30 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* */ 35 36/* 37 * NB. do not depend on the internals of this. It will be made opaque 38 * one day. 39 */ 40struct sshbuf { 41 u_char *d; /* Data */ 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 */ 51}; 52 53#ifndef SSHBUF_NO_DEPREACTED 54/* 55 * NB. Please do not use sshbuf_init() in new code. Please use sshbuf_new() 56 * instead. sshbuf_init() is deprectated and will go away soon (it is 57 * only included to allow compat with buffer_* in OpenSSH) 58 */ 59void sshbuf_init(struct sshbuf *buf); 60#endif 61 62/* 63 * Create a new sshbuf buffer. 64 * Returns pointer to buffer on success, or NULL on allocation failure. 65 */ 66struct sshbuf *sshbuf_new(void); 67 68/* 69 * Create a new, read-only sshbuf buffer from existing data. 70 * Returns pointer to buffer on success, or NULL on allocation failure. 71 */ 72struct sshbuf *sshbuf_from(const void *blob, size_t len); 73 74/* 75 * Create a new, read-only sshbuf buffer from the contents of an existing 76 * buffer. The contents of "buf" must not change in the lifetime of the 77 * resultant buffer. 78 * Returns pointer to buffer on success, or NULL on allocation failure. 79 */ 80struct sshbuf *sshbuf_fromb(struct sshbuf *buf); 81 82/* 83 * Create a new, read-only sshbuf buffer from the contents of a string in 84 * an existing buffer (the string is consumed in the process). 85 * The contents of "buf" must not change in the lifetime of the resultant 86 * buffer. 87 * Returns pointer to buffer on success, or NULL on allocation failure. 88 */ 89int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp); 90 91/* 92 * Clear and free buf 93 */ 94void sshbuf_free(struct sshbuf *buf); 95 96/* 97 * Reset buf, clearing its contents. NB. max_size is preserved. 98 */ 99void sshbuf_reset(struct sshbuf *buf); 100 101/* 102 * Return the maximum size of buf 103 */ 104size_t sshbuf_max_size(const struct sshbuf *buf); 105 106/* 107 * Set the maximum size of buf 108 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 109 */ 110int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size); 111 112/* 113 * Returns the length of data in buf 114 */ 115size_t sshbuf_len(const struct sshbuf *buf); 116 117/* 118 * Returns number of bytes left in buffer before hitting max_size. 119 */ 120size_t sshbuf_avail(const struct sshbuf *buf); 121 122/* 123 * Returns a read-only pointer to the start of the data in buf 124 */ 125const u_char *sshbuf_ptr(const struct sshbuf *buf); 126 127/* 128 * Returns a mutable pointer to the start of the data in buf, or 129 * NULL if the buffer is read-only. 130 */ 131u_char *sshbuf_mutable_ptr(const struct sshbuf *buf); 132 133/* 134 * Check whether a reservation of size len will succeed in buf 135 * Safer to use than direct comparisons again sshbuf_avail as it copes 136 * with unsigned overflows correctly. 137 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 138 */ 139int sshbuf_check_reserve(const struct sshbuf *buf, size_t len); 140 141/* 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. 145 */ 146int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp); 147 148/* 149 * Consume len bytes from the start of buf 150 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 151 */ 152int sshbuf_consume(struct sshbuf *buf, size_t len); 153 154/* 155 * Consume len bytes from the end of buf 156 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 157 */ 158int sshbuf_consume_end(struct sshbuf *buf, size_t len); 159 160/* Extract or deposit some bytes */ 161int sshbuf_get(struct sshbuf *buf, void *v, size_t len); 162int sshbuf_put(struct sshbuf *buf, const void *v, size_t len); 163int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v); 164 165/* Append using a printf(3) format */ 166int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...) 167 __attribute__((format(printf, 2, 3))); 168int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap); 169 170/* Functions to extract or store big-endian words of various sizes */ 171int sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp); 172int sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp); 173int sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp); 174int sshbuf_get_u8(struct sshbuf *buf, u_char *valp); 175int sshbuf_put_u64(struct sshbuf *buf, u_int64_t val); 176int sshbuf_put_u32(struct sshbuf *buf, u_int32_t val); 177int sshbuf_put_u16(struct sshbuf *buf, u_int16_t val); 178int sshbuf_put_u8(struct sshbuf *buf, u_char val); 179 180/* 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. 184 */ 185int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp); 186int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp); 187int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v); 188int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len); 189int sshbuf_put_cstring(struct sshbuf *buf, const char *v); 190int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v); 191 192/* 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. 196 */ 197int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp, 198 size_t *lenp); 199 200/* Skip past a string */ 201#define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL) 202 203/* Another variant: "peeks" into the buffer without modifying it */ 204int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp, 205 size_t *lenp); 206 207/* 208 * Functions to extract or store SSH wire encoded bignums and elliptic 209 * curve points. 210 */ 211int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len); 212int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf, 213 const u_char **valp, size_t *lenp); 214#ifdef WITH_OPENSSL 215int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v); 216int sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v); 217int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v); 218int sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v); 219# ifdef OPENSSL_HAS_ECC 220int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g); 221int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v); 222int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g); 223int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v); 224# endif /* OPENSSL_HAS_ECC */ 225#endif /* WITH_OPENSSL */ 226 227/* Dump the contents of the buffer in a human-readable format */ 228void sshbuf_dump(struct sshbuf *buf, FILE *f); 229 230/* Dump specified memory in a human-readable format */ 231void sshbuf_dump_data(const void *s, size_t len, FILE *f); 232 233/* Return the hexadecimal representation of the contents of the buffer */ 234char *sshbuf_dtob16(struct sshbuf *buf); 235 236/* Encode the contents of the buffer as base64 */ 237char *sshbuf_dtob64(struct sshbuf *buf); 238 239/* Decode base64 data and append it to the buffer */ 240int sshbuf_b64tod(struct sshbuf *buf, const char *b64); 241 242/* 243 * Duplicate the contents of a buffer to a string (caller to free). 244 * Returns NULL on buffer error, or if the buffer contains a premature 245 * nul character. 246 */ 247char *sshbuf_dup_string(struct sshbuf *buf); 248 249/* Macros for decoding/encoding integers */ 250#define PEEK_U64(p) \ 251 (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \ 252 ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \ 253 ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \ 254 ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \ 255 ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \ 256 ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \ 257 ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \ 258 (u_int64_t)(((const u_char *)(p))[7])) 259#define PEEK_U32(p) \ 260 (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \ 261 ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \ 262 ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \ 263 (u_int32_t)(((const u_char *)(p))[3])) 264#define PEEK_U16(p) \ 265 (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \ 266 (u_int16_t)(((const u_char *)(p))[1])) 267 268#define POKE_U64(p, v) \ 269 do { \ 270 const u_int64_t __v = (v); \ 271 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \ 272 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \ 273 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \ 274 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \ 275 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \ 276 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \ 277 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \ 278 ((u_char *)(p))[7] = __v & 0xff; \ 279 } while (0) 280#define POKE_U32(p, v) \ 281 do { \ 282 const u_int32_t __v = (v); \ 283 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \ 284 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \ 285 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \ 286 ((u_char *)(p))[3] = __v & 0xff; \ 287 } while (0) 288#define POKE_U16(p, v) \ 289 do { \ 290 const u_int16_t __v = (v); \ 291 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \ 292 ((u_char *)(p))[1] = __v & 0xff; \ 293 } while (0) 294 295/* Internal definitions follow. Exposed for regress tests */ 296#ifdef SSHBUF_INTERNAL 297 298/* 299 * Return the allocation size of buf 300 */ 301size_t sshbuf_alloc(const struct sshbuf *buf); 302 303/* 304 * Increment the reference count of buf. 305 */ 306int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent); 307 308/* 309 * Return the parent buffer of buf, or NULL if it has no parent. 310 */ 311const struct sshbuf *sshbuf_parent(const struct sshbuf *buf); 312 313/* 314 * Return the reference count of buf 315 */ 316u_int sshbuf_refcount(const struct sshbuf *buf); 317 318# define SSHBUF_SIZE_INIT 256 /* Initial allocation */ 319# define SSHBUF_SIZE_INC 256 /* Preferred increment length */ 320# define SSHBUF_PACK_MIN 8192 /* Minimim packable offset */ 321 322/* # define SSHBUF_ABORT abort */ 323/* # define SSHBUF_DEBUG */ 324 325# ifndef SSHBUF_ABORT 326# define SSHBUF_ABORT() 327# endif 328 329# ifdef SSHBUF_DEBUG 330# define SSHBUF_TELL(what) do { \ 331 printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \ 332 __FILE__, __LINE__, __func__, what, \ 333 buf->size, buf->alloc, buf->off, buf->max_size); \ 334 fflush(stdout); \ 335 } while (0) 336# define SSHBUF_DBG(x) do { \ 337 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \ 338 printf x; \ 339 printf("\n"); \ 340 fflush(stdout); \ 341 } while (0) 342# else 343# define SSHBUF_TELL(what) 344# define SSHBUF_DBG(x) 345# endif 346#endif /* SSHBUF_INTERNAL */ 347 348#endif /* _SSHBUF_H */ 349