1/* $OpenBSD: sshbuf.h,v 1.11 2018/07/09 21:56:06 markus 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/* 54 * Create a new sshbuf buffer. 55 * Returns pointer to buffer on success, or NULL on allocation failure. 56 */ 57struct sshbuf *sshbuf_new(void); 58 59/* 60 * Create a new, read-only sshbuf buffer from existing data. 61 * Returns pointer to buffer on success, or NULL on allocation failure. 62 */ 63struct sshbuf *sshbuf_from(const void *blob, size_t len); 64 65/* 66 * Create a new, read-only sshbuf buffer from the contents of an existing 67 * buffer. The contents of "buf" must not change in the lifetime of the 68 * resultant buffer. 69 * Returns pointer to buffer on success, or NULL on allocation failure. 70 */ 71struct sshbuf *sshbuf_fromb(struct sshbuf *buf); 72 73/* 74 * Create a new, read-only sshbuf buffer from the contents of a string in 75 * an existing buffer (the string is consumed in the process). 76 * The contents of "buf" must not change in the lifetime of the resultant 77 * buffer. 78 * Returns pointer to buffer on success, or NULL on allocation failure. 79 */ 80int sshbuf_froms(struct sshbuf *buf, struct sshbuf **bufp); 81 82/* 83 * Clear and free buf 84 */ 85void sshbuf_free(struct sshbuf *buf); 86 87/* 88 * Reset buf, clearing its contents. NB. max_size is preserved. 89 */ 90void sshbuf_reset(struct sshbuf *buf); 91 92/* 93 * Return the maximum size of buf 94 */ 95size_t sshbuf_max_size(const struct sshbuf *buf); 96 97/* 98 * Set the maximum size of buf 99 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 100 */ 101int sshbuf_set_max_size(struct sshbuf *buf, size_t max_size); 102 103/* 104 * Returns the length of data in buf 105 */ 106size_t sshbuf_len(const struct sshbuf *buf); 107 108/* 109 * Returns number of bytes left in buffer before hitting max_size. 110 */ 111size_t sshbuf_avail(const struct sshbuf *buf); 112 113/* 114 * Returns a read-only pointer to the start of the data in buf 115 */ 116const u_char *sshbuf_ptr(const struct sshbuf *buf); 117 118/* 119 * Returns a mutable pointer to the start of the data in buf, or 120 * NULL if the buffer is read-only. 121 */ 122u_char *sshbuf_mutable_ptr(const struct sshbuf *buf); 123 124/* 125 * Check whether a reservation of size len will succeed in buf 126 * Safer to use than direct comparisons again sshbuf_avail as it copes 127 * with unsigned overflows correctly. 128 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 129 */ 130int sshbuf_check_reserve(const struct sshbuf *buf, size_t len); 131 132/* 133 * Preallocates len additional bytes in buf. 134 * Useful for cases where the caller knows how many bytes will ultimately be 135 * required to avoid realloc in the buffer code. 136 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 137 */ 138int sshbuf_allocate(struct sshbuf *buf, size_t len); 139 140/* 141 * Reserve len bytes in buf. 142 * Returns 0 on success and a pointer to the first reserved byte via the 143 * optional dpp parameter or a negative * SSH_ERR_* error code on failure. 144 */ 145int sshbuf_reserve(struct sshbuf *buf, size_t len, u_char **dpp); 146 147/* 148 * Consume len bytes from the start of buf 149 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 150 */ 151int sshbuf_consume(struct sshbuf *buf, size_t len); 152 153/* 154 * Consume len bytes from the end of buf 155 * Returns 0 on success, or a negative SSH_ERR_* error code on failure. 156 */ 157int sshbuf_consume_end(struct sshbuf *buf, size_t len); 158 159/* Extract or deposit some bytes */ 160int sshbuf_get(struct sshbuf *buf, void *v, size_t len); 161int sshbuf_put(struct sshbuf *buf, const void *v, size_t len); 162int sshbuf_putb(struct sshbuf *buf, const struct sshbuf *v); 163 164/* Append using a printf(3) format */ 165int sshbuf_putf(struct sshbuf *buf, const char *fmt, ...) 166 __attribute__((format(printf, 2, 3))); 167int sshbuf_putfv(struct sshbuf *buf, const char *fmt, va_list ap); 168 169/* Functions to extract or store big-endian words of various sizes */ 170int sshbuf_get_u64(struct sshbuf *buf, u_int64_t *valp); 171int sshbuf_get_u32(struct sshbuf *buf, u_int32_t *valp); 172int sshbuf_get_u16(struct sshbuf *buf, u_int16_t *valp); 173int sshbuf_get_u8(struct sshbuf *buf, u_char *valp); 174int sshbuf_put_u64(struct sshbuf *buf, u_int64_t val); 175int sshbuf_put_u32(struct sshbuf *buf, u_int32_t val); 176int sshbuf_put_u16(struct sshbuf *buf, u_int16_t val); 177int sshbuf_put_u8(struct sshbuf *buf, u_char val); 178 179#if defined(__FreeBSD__) && defined(__i386__) 180#define sshbuf_get_time(b, vp) sshbuf_get_u32((b), (u_int32_t *)(vp)) 181#define sshbuf_put_time(b, v) sshbuf_put_u32((b), (u_int32_t)(v)) 182#else 183#define sshbuf_get_time(b, vp) sshbuf_get_u64((b), (u_int64_t *)(vp)) 184#define sshbuf_put_time(b, v) sshbuf_put_u64((b), (u_int64_t)(v)) 185#endif 186 187/* 188 * Functions to extract or store SSH wire encoded strings (u32 len || data) 189 * The "cstring" variants admit no \0 characters in the string contents. 190 * Caller must free *valp. 191 */ 192int sshbuf_get_string(struct sshbuf *buf, u_char **valp, size_t *lenp); 193int sshbuf_get_cstring(struct sshbuf *buf, char **valp, size_t *lenp); 194int sshbuf_get_stringb(struct sshbuf *buf, struct sshbuf *v); 195int sshbuf_put_string(struct sshbuf *buf, const void *v, size_t len); 196int sshbuf_put_cstring(struct sshbuf *buf, const char *v); 197int sshbuf_put_stringb(struct sshbuf *buf, const struct sshbuf *v); 198 199/* 200 * "Direct" variant of sshbuf_get_string, returns pointer into the sshbuf to 201 * avoid an malloc+memcpy. The pointer is guaranteed to be valid until the 202 * next sshbuf-modifying function call. Caller does not free. 203 */ 204int sshbuf_get_string_direct(struct sshbuf *buf, const u_char **valp, 205 size_t *lenp); 206 207/* Skip past a string */ 208#define sshbuf_skip_string(buf) sshbuf_get_string_direct(buf, NULL, NULL) 209 210/* Another variant: "peeks" into the buffer without modifying it */ 211int sshbuf_peek_string_direct(const struct sshbuf *buf, const u_char **valp, 212 size_t *lenp); 213/* XXX peek_u8 / peek_u32 */ 214 215/* 216 * Functions to extract or store SSH wire encoded bignums and elliptic 217 * curve points. 218 */ 219int sshbuf_put_bignum2_bytes(struct sshbuf *buf, const void *v, size_t len); 220int sshbuf_get_bignum2_bytes_direct(struct sshbuf *buf, 221 const u_char **valp, size_t *lenp); 222#ifdef WITH_OPENSSL 223int sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v); 224int sshbuf_get_bignum1(struct sshbuf *buf, BIGNUM *v); 225int sshbuf_put_bignum2(struct sshbuf *buf, const BIGNUM *v); 226int sshbuf_put_bignum1(struct sshbuf *buf, const BIGNUM *v); 227# ifdef OPENSSL_HAS_ECC 228int sshbuf_get_ec(struct sshbuf *buf, EC_POINT *v, const EC_GROUP *g); 229int sshbuf_get_eckey(struct sshbuf *buf, EC_KEY *v); 230int sshbuf_put_ec(struct sshbuf *buf, const EC_POINT *v, const EC_GROUP *g); 231int sshbuf_put_eckey(struct sshbuf *buf, const EC_KEY *v); 232# endif /* OPENSSL_HAS_ECC */ 233#endif /* WITH_OPENSSL */ 234 235/* Dump the contents of the buffer in a human-readable format */ 236void sshbuf_dump(struct sshbuf *buf, FILE *f); 237 238/* Dump specified memory in a human-readable format */ 239void sshbuf_dump_data(const void *s, size_t len, FILE *f); 240 241/* Return the hexadecimal representation of the contents of the buffer */ 242char *sshbuf_dtob16(struct sshbuf *buf); 243 244/* Encode the contents of the buffer as base64 */ 245char *sshbuf_dtob64(struct sshbuf *buf); 246 247/* Decode base64 data and append it to the buffer */ 248int sshbuf_b64tod(struct sshbuf *buf, const char *b64); 249 250/* 251 * Duplicate the contents of a buffer to a string (caller to free). 252 * Returns NULL on buffer error, or if the buffer contains a premature 253 * nul character. 254 */ 255char *sshbuf_dup_string(struct sshbuf *buf); 256 257/* 258 * store struct pwd 259 */ 260int sshbuf_put_passwd(struct sshbuf *buf, const struct passwd *pwent); 261 262/* 263 * extract struct pwd 264 */ 265struct passwd *sshbuf_get_passwd(struct sshbuf *buf); 266 267/* 268 * free struct passwd obtained from sshbuf_get_passwd. 269 */ 270void sshbuf_free_passwd(struct passwd *pwent); 271 272/* Macros for decoding/encoding integers */ 273#define PEEK_U64(p) \ 274 (((u_int64_t)(((const u_char *)(p))[0]) << 56) | \ 275 ((u_int64_t)(((const u_char *)(p))[1]) << 48) | \ 276 ((u_int64_t)(((const u_char *)(p))[2]) << 40) | \ 277 ((u_int64_t)(((const u_char *)(p))[3]) << 32) | \ 278 ((u_int64_t)(((const u_char *)(p))[4]) << 24) | \ 279 ((u_int64_t)(((const u_char *)(p))[5]) << 16) | \ 280 ((u_int64_t)(((const u_char *)(p))[6]) << 8) | \ 281 (u_int64_t)(((const u_char *)(p))[7])) 282#define PEEK_U32(p) \ 283 (((u_int32_t)(((const u_char *)(p))[0]) << 24) | \ 284 ((u_int32_t)(((const u_char *)(p))[1]) << 16) | \ 285 ((u_int32_t)(((const u_char *)(p))[2]) << 8) | \ 286 (u_int32_t)(((const u_char *)(p))[3])) 287#define PEEK_U16(p) \ 288 (((u_int16_t)(((const u_char *)(p))[0]) << 8) | \ 289 (u_int16_t)(((const u_char *)(p))[1])) 290 291#define POKE_U64(p, v) \ 292 do { \ 293 const u_int64_t __v = (v); \ 294 ((u_char *)(p))[0] = (__v >> 56) & 0xff; \ 295 ((u_char *)(p))[1] = (__v >> 48) & 0xff; \ 296 ((u_char *)(p))[2] = (__v >> 40) & 0xff; \ 297 ((u_char *)(p))[3] = (__v >> 32) & 0xff; \ 298 ((u_char *)(p))[4] = (__v >> 24) & 0xff; \ 299 ((u_char *)(p))[5] = (__v >> 16) & 0xff; \ 300 ((u_char *)(p))[6] = (__v >> 8) & 0xff; \ 301 ((u_char *)(p))[7] = __v & 0xff; \ 302 } while (0) 303#define POKE_U32(p, v) \ 304 do { \ 305 const u_int32_t __v = (v); \ 306 ((u_char *)(p))[0] = (__v >> 24) & 0xff; \ 307 ((u_char *)(p))[1] = (__v >> 16) & 0xff; \ 308 ((u_char *)(p))[2] = (__v >> 8) & 0xff; \ 309 ((u_char *)(p))[3] = __v & 0xff; \ 310 } while (0) 311#define POKE_U16(p, v) \ 312 do { \ 313 const u_int16_t __v = (v); \ 314 ((u_char *)(p))[0] = (__v >> 8) & 0xff; \ 315 ((u_char *)(p))[1] = __v & 0xff; \ 316 } while (0) 317 318/* Internal definitions follow. Exposed for regress tests */ 319#ifdef SSHBUF_INTERNAL 320 321/* 322 * Return the allocation size of buf 323 */ 324size_t sshbuf_alloc(const struct sshbuf *buf); 325 326/* 327 * Increment the reference count of buf. 328 */ 329int sshbuf_set_parent(struct sshbuf *child, struct sshbuf *parent); 330 331/* 332 * Return the parent buffer of buf, or NULL if it has no parent. 333 */ 334const struct sshbuf *sshbuf_parent(const struct sshbuf *buf); 335 336/* 337 * Return the reference count of buf 338 */ 339u_int sshbuf_refcount(const struct sshbuf *buf); 340 341# define SSHBUF_SIZE_INIT 256 /* Initial allocation */ 342# define SSHBUF_SIZE_INC 256 /* Preferred increment length */ 343# define SSHBUF_PACK_MIN 8192 /* Minimim packable offset */ 344 345/* # define SSHBUF_ABORT abort */ 346/* # define SSHBUF_DEBUG */ 347 348# ifndef SSHBUF_ABORT 349# define SSHBUF_ABORT() 350# endif 351 352# ifdef SSHBUF_DEBUG 353# define SSHBUF_TELL(what) do { \ 354 printf("%s:%d %s: %s size %zu alloc %zu off %zu max %zu\n", \ 355 __FILE__, __LINE__, __func__, what, \ 356 buf->size, buf->alloc, buf->off, buf->max_size); \ 357 fflush(stdout); \ 358 } while (0) 359# define SSHBUF_DBG(x) do { \ 360 printf("%s:%d %s: ", __FILE__, __LINE__, __func__); \ 361 printf x; \ 362 printf("\n"); \ 363 fflush(stdout); \ 364 } while (0) 365# else 366# define SSHBUF_TELL(what) 367# define SSHBUF_DBG(x) 368# endif 369#endif /* SSHBUF_INTERNAL */ 370 371#endif /* _SSHBUF_H */ 372