src/common/util.h

   1 /* Copyright (c) 2003-2004, Roger Dingledine
   2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   3  * Copyright (c) 2007-2013, The Tor Project, Inc. */
   4 /* See LICENSE for licensing information */
   5
   6 /**
   7  * \file util.h
   8  * \brief Headers for util.c
   9  **/
  10
  11 #ifndef TOR_UTIL_H
  12 #define TOR_UTIL_H
  13
  14 #include "orconfig.h"
  15 #include "torint.h"
  16 #include "compat.h"
  17 #include "di_ops.h"
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #ifdef _WIN32
  21 /* for the correct alias to struct stat */
  22 #include <sys/stat.h>
  23 #endif
  24
  25 #ifndef O_BINARY
  26 #define O_BINARY 0
  27 #endif
  28 #ifndef O_TEXT
  29 #define O_TEXT 0
  30 #endif
  31
  32 /* Replace assert() with a variant that sends failures to the log before
  33  * calling assert() normally.
  34  */
  35 #ifdef NDEBUG
  36 /* Nobody should ever want to build with NDEBUG set.  99% of our asserts will
  37  * be outside the critical path anyway, so it's silly to disable bug-checking
  38  * throughout the entire program just because a few asserts are slowing you
  39  * down.  Profile, optimize the critical path, and keep debugging on.
  40  *
  41  * And I'm not just saying that because some of our asserts check
  42  * security-critical properties.
  43  */
  44 #error "Sorry; we don't support building with NDEBUG."
  45 #endif
  46
  47 /** Like assert(3), but send assertion failures to the log as well as to
  48  * stderr. */
  49 #define tor_assert(expr) STMT_BEGIN                                     \
  50     if (PREDICT_UNLIKELY(!(expr))) {                                    \
  51       log_err(LD_BUG, "%s:%d: %s: Assertion %s failed; aborting.",      \
  52           SHORT_FILE__, __LINE__, __func__, #expr);                     \
  53       fprintf(stderr,"%s:%d %s: Assertion %s failed; aborting.\n",      \
  54               SHORT_FILE__, __LINE__, __func__, #expr);                 \
  55       abort();                                                          \
  56     } STMT_END
  57
  58 /* If we're building with dmalloc, we want all of our memory allocation
  59  * functions to take an extra file/line pair of arguments.  If not, not.
  60  * We define DMALLOC_PARAMS to the extra parameters to insert in the
  61  * function prototypes, and DMALLOC_ARGS to the extra arguments to add
  62  * to calls. */
  63 #ifdef USE_DMALLOC
  64 #define DMALLOC_PARAMS , const char *file, const int line
  65 #define DMALLOC_ARGS , SHORT_FILE__, __LINE__
  66 #else
  67 #define DMALLOC_PARAMS
  68 #define DMALLOC_ARGS
  69 #endif
  70
  71 /** Define this if you want Tor to crash when any problem comes up,
  72  * so you can get a coredump and track things down. */
  73 // #define tor_fragile_assert() tor_assert(0)
  74 #define tor_fragile_assert()
  75
  76 /* Memory management */
  77 void *tor_malloc_(size_t size DMALLOC_PARAMS) ATTR_MALLOC;
  78 void *tor_malloc_zero_(size_t size DMALLOC_PARAMS) ATTR_MALLOC;
  79 void *tor_calloc_(size_t nmemb, size_t size DMALLOC_PARAMS) ATTR_MALLOC;
  80 void *tor_realloc_(void *ptr, size_t size DMALLOC_PARAMS);
  81 char *tor_strdup_(const char *s DMALLOC_PARAMS) ATTR_MALLOC ATTR_NONNULL((1));
  82 char *tor_strndup_(const char *s, size_t n DMALLOC_PARAMS)
  83   ATTR_MALLOC ATTR_NONNULL((1));
  84 void *tor_memdup_(const void *mem, size_t len DMALLOC_PARAMS)
  85   ATTR_MALLOC ATTR_NONNULL((1));
  86 void tor_free_(void *mem);
  87 #ifdef USE_DMALLOC
  88 extern int dmalloc_free(const char *file, const int line, void *pnt,
  89                         const int func_id);
  90 #define tor_free(p) STMT_BEGIN \
  91     if (PREDICT_LIKELY((p)!=NULL)) {                \
  92       dmalloc_free(SHORT_FILE__, __LINE__, (p), 0); \
  93       (p)=NULL;                                     \
  94     }                                               \
  95   STMT_END
  96 #else
  97 /** Release memory allocated by tor_malloc, tor_realloc, tor_strdup, etc.
  98  * Unlike the free() function, tor_free() will still work on NULL pointers,
  99  * and it sets the pointer value to NULL after freeing it.
 100  *
 101  * This is a macro.  If you need a function pointer to release memory from
 102  * tor_malloc(), use tor_free_().
 103  */
 104 #define tor_free(p) STMT_BEGIN                                 \
 105     if (PREDICT_LIKELY((p)!=NULL)) {                           \
 106       free(p);                                                 \
 107       (p)=NULL;                                                \
 108     }                                                          \
 109   STMT_END
 110 #endif
 111
 112 #define tor_malloc(size)       tor_malloc_(size DMALLOC_ARGS)
 113 #define tor_malloc_zero(size)  tor_malloc_zero_(size DMALLOC_ARGS)
 114 #define tor_calloc(nmemb,size) tor_calloc_(nmemb, size DMALLOC_ARGS)
 115 #define tor_realloc(ptr, size) tor_realloc_(ptr, size DMALLOC_ARGS)
 116 #define tor_strdup(s)          tor_strdup_(s DMALLOC_ARGS)
 117 #define tor_strndup(s, n)      tor_strndup_(s, n DMALLOC_ARGS)
 118 #define tor_memdup(s, n)       tor_memdup_(s, n DMALLOC_ARGS)
 119
 120 void tor_log_mallinfo(int severity);
 121
 122 /** Return the offset of <b>member</b> within the type <b>tp</b>, in bytes */
 123 #if defined(__GNUC__) && __GNUC__ > 3
 124 #define STRUCT_OFFSET(tp, member) __builtin_offsetof(tp, member)
 125 #else
 126  #define STRUCT_OFFSET(tp, member) \
 127    ((off_t) (((char*)&((tp*)0)->member)-(char*)0))
 128 #endif
 129
 130 /** Macro: yield a pointer to the field at position <b>off</b> within the
 131  * structure <b>st</b>.  Example:
 132  * <pre>
 133  *   struct a { int foo; int bar; } x;
 134  *   off_t bar_offset = STRUCT_OFFSET(struct a, bar);
 135  *   int *bar_p = STRUCT_VAR_P(&x, bar_offset);
 136  *   *bar_p = 3;
 137  * </pre>
 138  */
 139 #define STRUCT_VAR_P(st, off) ((void*) ( ((char*)(st)) + (off) ) )
 140
 141 /** Macro: yield a pointer to an enclosing structure given a pointer to
 142  * a substructure at offset <b>off</b>. Example:
 143  * <pre>
 144  *   struct base { ... };
 145  *   struct subtype { int x; struct base b; } x;
 146  *   struct base *bp = &x.base;
 147  *   struct *sp = SUBTYPE_P(bp, struct subtype, b);
 148  * </pre>
 149  */
 150 #define SUBTYPE_P(p, subtype, basemember) \
 151   ((void*) ( ((char*)(p)) - STRUCT_OFFSET(subtype, basemember) ))
 152
 153 /* Logic */
 154 /** Macro: true if two values have the same boolean value. */
 155 #define bool_eq(a,b) (!(a)==!(b))
 156 /** Macro: true if two values have different boolean values. */
 157 #define bool_neq(a,b) (!(a)!=!(b))
 158
 159 /* Math functions */
 160 double tor_mathlog(double d) ATTR_CONST;
 161 long tor_lround(double d) ATTR_CONST;
 162 int64_t tor_llround(double d) ATTR_CONST;
 163 int tor_log2(uint64_t u64) ATTR_CONST;
 164 uint64_t round_to_power_of_2(uint64_t u64);
 165 unsigned round_to_next_multiple_of(unsigned number, unsigned divisor);
 166 uint32_t round_uint32_to_next_multiple_of(uint32_t number, uint32_t divisor);
 167 uint64_t round_uint64_to_next_multiple_of(uint64_t number, uint64_t divisor);
 168 int n_bits_set_u8(uint8_t v);
 169
 170 /* Compute the CEIL of <b>a</b> divided by <b>b</b>, for nonnegative <b>a</b>
 171  * and positive <b>b</b>.  Works on integer types only. Not defined if a+b can
 172  * overflow. */
 173 #define CEIL_DIV(a,b) (((a)+(b)-1)/(b))
 174
 175 /* String manipulation */
 176
 177 /** Allowable characters in a hexadecimal string. */
 178 #define HEX_CHARACTERS "0123456789ABCDEFabcdef"
 179 void tor_strlower(char *s) ATTR_NONNULL((1));
 180 void tor_strupper(char *s) ATTR_NONNULL((1));
 181 int tor_strisprint(const char *s) ATTR_NONNULL((1));
 182 int tor_strisnonupper(const char *s) ATTR_NONNULL((1));
 183 int strcmp_opt(const char *s1, const char *s2);
 184 int strcmpstart(const char *s1, const char *s2) ATTR_NONNULL((1,2));
 185 int strcmp_len(const char *s1, const char *s2, size_t len) ATTR_NONNULL((1,2));
 186 int strcasecmpstart(const char *s1, const char *s2) ATTR_NONNULL((1,2));
 187 int strcmpend(const char *s1, const char *s2) ATTR_NONNULL((1,2));
 188 int strcasecmpend(const char *s1, const char *s2) ATTR_NONNULL((1,2));
 189 int fast_memcmpstart(const void *mem, size_t memlen, const char *prefix);
 190 void tor_strclear(char *s);
 191
 192 void tor_strstrip(char *s, const char *strip) ATTR_NONNULL((1,2));
 193 long tor_parse_long(const char *s, int base, long min,
 194                     long max, int *ok, char **next);
 195 unsigned long tor_parse_ulong(const char *s, int base, unsigned long min,
 196                               unsigned long max, int *ok, char **next);
 197 double tor_parse_double(const char *s, double min, double max, int *ok,
 198                         char **next);
 199 uint64_t tor_parse_uint64(const char *s, int base, uint64_t min,
 200                          uint64_t max, int *ok, char **next);
 201 const char *hex_str(const char *from, size_t fromlen) ATTR_NONNULL((1));
 202 const char *eat_whitespace(const char *s);
 203 const char *eat_whitespace_eos(const char *s, const char *eos);
 204 const char *eat_whitespace_no_nl(const char *s);
 205 const char *eat_whitespace_eos_no_nl(const char *s, const char *eos);
 206 const char *find_whitespace(const char *s);
 207 const char *find_whitespace_eos(const char *s, const char *eos);
 208 const char *find_str_at_start_of_line(const char *haystack,
 209                                       const char *needle);
 210 int string_is_C_identifier(const char *string);
 211
 212 int tor_mem_is_zero(const char *mem, size_t len);
 213 int tor_digest_is_zero(const char *digest);
 214 int tor_digest256_is_zero(const char *digest);
 215 char *esc_for_log(const char *string) ATTR_MALLOC;
 216 const char *escaped(const char *string);
 217 struct smartlist_t;
 218 void wrap_string(struct smartlist_t *out, const char *string, size_t width,
 219                  const char *prefix0, const char *prefixRest);
 220 int tor_vsscanf(const char *buf, const char *pattern, va_list ap)
 221 #ifdef __GNUC__
 222   __attribute__((format(scanf, 2, 0)))
 223 #endif
 224   ;
 225 int tor_sscanf(const char *buf, const char *pattern, ...)
 226 #ifdef __GNUC__
 227   __attribute__((format(scanf, 2, 3)))
 228 #endif
 229   ;
 230
 231 void smartlist_add_asprintf(struct smartlist_t *sl, const char *pattern, ...)
 232   CHECK_PRINTF(2, 3);
 233 void smartlist_add_vasprintf(struct smartlist_t *sl, const char *pattern,
 234                              va_list args)
 235   CHECK_PRINTF(2, 0);
 236
 237 int hex_decode_digit(char c);
 238 void base16_encode(char *dest, size_t destlen, const char *src, size_t srclen);
 239 int base16_decode(char *dest, size_t destlen, const char *src, size_t srclen);
 240
 241 /* Time helpers */
 242 long tv_udiff(const struct timeval *start, const struct timeval *end);
 243 long tv_mdiff(const struct timeval *start, const struct timeval *end);
 244 int tor_timegm(const struct tm *tm, time_t *time_out);
 245 #define RFC1123_TIME_LEN 29
 246 void format_rfc1123_time(char *buf, time_t t);
 247 int parse_rfc1123_time(const char *buf, time_t *t);
 248 #define ISO_TIME_LEN 19
 249 #define ISO_TIME_USEC_LEN (ISO_TIME_LEN+7)
 250 void format_local_iso_time(char *buf, time_t t);
 251 void format_iso_time(char *buf, time_t t);
 252 void format_iso_time_nospace(char *buf, time_t t);
 253 void format_iso_time_nospace_usec(char *buf, const struct timeval *tv);
 254 int parse_iso_time(const char *buf, time_t *t);
 255 int parse_http_time(const char *buf, struct tm *tm);
 256 int format_time_interval(char *out, size_t out_len, long interval);
 257
 258 /* Cached time */
 259 #ifdef TIME_IS_FAST
 260 #define approx_time() time(NULL)
 261 #define update_approx_time(t) STMT_NIL
 262 #else
 263 time_t approx_time(void);
 264 void update_approx_time(time_t now);
 265 #endif
 266
 267 /* Rate-limiter */
 268
 269 /** A ratelim_t remembers how often an event is occurring, and how often
 270  * it's allowed to occur.  Typical usage is something like:
 271  *
 272    <pre>
 273     if (possibly_very_frequent_event()) {
 274       const int INTERVAL = 300;
 275       static ratelim_t warning_limit = RATELIM_INIT(INTERVAL);
 276       char *m;
 277       if ((m = rate_limit_log(&warning_limit, approx_time()))) {
 278         log_warn(LD_GENERAL, "The event occurred!%s", m);
 279         tor_free(m);
 280       }
 281     }
 282    </pre>
 283
 284    As a convenience wrapper for logging, you can replace the above with:
 285    <pre>
 286    if (possibly_very_frequent_event()) {
 287      static ratelim_t warning_limit = RATELIM_INIT(300);
 288      log_fn_ratelim(&warning_limit, LOG_WARN, LD_GENERAL,
 289                     "The event occurred!");
 290    }
 291    </pre>
 292  */
 293 typedef struct ratelim_t {
 294   int rate;
 295   time_t last_allowed;
 296   int n_calls_since_last_time;
 297 } ratelim_t;
 298
 299 #define RATELIM_INIT(r) { (r), 0, 0 }
 300
 301 char *rate_limit_log(ratelim_t *lim, time_t now);
 302
 303 /* File helpers */
 304 ssize_t write_all(tor_socket_t fd, const char *buf, size_t count,int isSocket);
 305 ssize_t read_all(tor_socket_t fd, char *buf, size_t count, int isSocket);
 306
 307 /** Status of an I/O stream. */
 308 enum stream_status {
 309   IO_STREAM_OKAY,
 310   IO_STREAM_EAGAIN,
 311   IO_STREAM_TERM,
 312   IO_STREAM_CLOSED
 313 };
 314
 315 const char *stream_status_to_string(enum stream_status stream_status);
 316
 317 enum stream_status get_string_from_pipe(FILE *stream, char *buf, size_t count);
 318
 319 /** Return values from file_status(); see that function's documentation
 320  * for details. */
 321 typedef enum { FN_ERROR, FN_NOENT, FN_FILE, FN_DIR } file_status_t;
 322 file_status_t file_status(const char *filename);
 323
 324 /** Possible behaviors for check_private_dir() on encountering a nonexistent
 325  * directory; see that function's documentation for details. */
 326 typedef unsigned int cpd_check_t;
 327 #define CPD_NONE 0
 328 #define CPD_CREATE 1
 329 #define CPD_CHECK 2
 330 #define CPD_GROUP_OK 4
 331 #define CPD_CHECK_MODE_ONLY 8
 332 int check_private_dir(const char *dirname, cpd_check_t check,
 333                       const char *effective_user);
 334 #define OPEN_FLAGS_REPLACE (O_WRONLY|O_CREAT|O_TRUNC)
 335 #define OPEN_FLAGS_APPEND (O_WRONLY|O_CREAT|O_APPEND)
 336 #define OPEN_FLAGS_DONT_REPLACE (O_CREAT|O_EXCL|O_APPEND|O_WRONLY)
 337 typedef struct open_file_t open_file_t;
 338 int start_writing_to_file(const char *fname, int open_flags, int mode,
 339                           open_file_t **data_out);
 340 FILE *start_writing_to_stdio_file(const char *fname, int open_flags, int mode,
 341                                   open_file_t **data_out);
 342 FILE *fdopen_file(open_file_t *file_data);
 343 int finish_writing_to_file(open_file_t *file_data);
 344 int abort_writing_to_file(open_file_t *file_data);
 345 int write_str_to_file(const char *fname, const char *str, int bin);
 346 int write_bytes_to_file(const char *fname, const char *str, size_t len,
 347                         int bin);
 348 /** An ad-hoc type to hold a string of characters and a count; used by
 349  * write_chunks_to_file. */
 350 typedef struct sized_chunk_t {
 351   const char *bytes;
 352   size_t len;
 353 } sized_chunk_t;
 354 int write_chunks_to_file(const char *fname, const struct smartlist_t *chunks,
 355                          int bin);
 356 int append_bytes_to_file(const char *fname, const char *str, size_t len,
 357                          int bin);
 358 int write_bytes_to_new_file(const char *fname, const char *str, size_t len,
 359                             int bin);
 360
 361 /** Flag for read_file_to_str: open the file in binary mode. */
 362 #define RFTS_BIN            1
 363 /** Flag for read_file_to_str: it's okay if the file doesn't exist. */
 364 #define RFTS_IGNORE_MISSING 2
 365
 366 #ifndef _WIN32
 367 struct stat;
 368 #endif
 369 char *read_file_to_str(const char *filename, int flags, struct stat *stat_out)
 370   ATTR_MALLOC;
 371 char *read_file_to_str_until_eof(int fd, size_t max_bytes_to_read,
 372                                  size_t *sz_out)
 373   ATTR_MALLOC;
 374 const char *parse_config_line_from_str(const char *line,
 375                                        char **key_out, char **value_out);
 376 char *expand_filename(const char *filename);
 377 struct smartlist_t *tor_listdir(const char *dirname);
 378 int path_is_relative(const char *filename);
 379
 380 /* Process helpers */
 381 void start_daemon(void);
 382 void finish_daemon(const char *desired_cwd);
 383 void write_pidfile(char *filename);
 384
 385 /* Port forwarding */
 386 void tor_check_port_forwarding(const char *filename,
 387                                struct smartlist_t *ports_to_forward,
 388                                time_t now);
 389
 390 typedef struct process_handle_t process_handle_t;
 391 typedef struct process_environment_t process_environment_t;
 392 int tor_spawn_background(const char *const filename, const char **argv,
 393                          process_environment_t *env,
 394                          process_handle_t **process_handle_out);
 395
 396 #define SPAWN_ERROR_MESSAGE "ERR: Failed to spawn background process - code "
 397
 398 #ifdef _WIN32
 399 HANDLE load_windows_system_library(const TCHAR *library_name);
 400 #endif
 401
 402 int environment_variable_names_equal(const char *s1, const char *s2);
 403
 404 /* DOCDOC process_environment_t */
 405 struct process_environment_t {
 406   /** A pointer to a sorted empty-string-terminated sequence of
 407    * NUL-terminated strings of the form "NAME=VALUE". */
 408   char *windows_environment_block;
 409   /** A pointer to a NULL-terminated array of pointers to
 410    * NUL-terminated strings of the form "NAME=VALUE". */
 411   char **unixoid_environment_block;
 412 };
 413
 414 process_environment_t *process_environment_make(struct smartlist_t *env_vars);
 415 void process_environment_free(process_environment_t *env);
 416
 417 struct smartlist_t *get_current_process_environment_variables(void);
 418
 419 void set_environment_variable_in_smartlist(struct smartlist_t *env_vars,
 420                                            const char *new_var,
 421                                            void (*free_old)(void*),
 422                                            int free_p);
 423
 424 /* Values of process_handle_t.status. PROCESS_STATUS_NOTRUNNING must be
 425  * 0 because tor_check_port_forwarding depends on this being the initial
 426  * statue of the static instance of process_handle_t */
 427 #define PROCESS_STATUS_NOTRUNNING 0
 428 #define PROCESS_STATUS_RUNNING 1
 429 #define PROCESS_STATUS_ERROR -1
 430
 431 #ifdef UTIL_PRIVATE
 432 /** Structure to represent the state of a process with which Tor is
 433  * communicating. The contents of this structure are private to util.c */
 434 struct process_handle_t {
 435   /** One of the PROCESS_STATUS_* values */
 436   int status;
 437 #ifdef _WIN32
 438   HANDLE stdout_pipe;
 439   HANDLE stderr_pipe;
 440   PROCESS_INFORMATION pid;
 441 #else
 442   int stdout_pipe;
 443   int stderr_pipe;
 444   FILE *stdout_handle;
 445   FILE *stderr_handle;
 446   pid_t pid;
 447 #endif // _WIN32
 448 };
 449 #endif
 450
 451 /* Return values of tor_get_exit_code() */
 452 #define PROCESS_EXIT_RUNNING 1
 453 #define PROCESS_EXIT_EXITED 0
 454 #define PROCESS_EXIT_ERROR -1
 455 int tor_get_exit_code(const process_handle_t *process_handle,
 456                       int block, int *exit_code);
 457 int tor_split_lines(struct smartlist_t *sl, char *buf, int len);
 458 #ifdef _WIN32
 459 ssize_t tor_read_all_handle(HANDLE h, char *buf, size_t count,
 460                             const process_handle_t *process);
 461 #else
 462 ssize_t tor_read_all_handle(FILE *h, char *buf, size_t count,
 463                             const process_handle_t *process,
 464                             int *eof);
 465 #endif
 466 ssize_t tor_read_all_from_process_stdout(
 467     const process_handle_t *process_handle, char *buf, size_t count);
 468 ssize_t tor_read_all_from_process_stderr(
 469     const process_handle_t *process_handle, char *buf, size_t count);
 470 char *tor_join_win_cmdline(const char *argv[]);
 471
 472 int tor_process_get_pid(process_handle_t *process_handle);
 473 #ifdef _WIN32
 474 HANDLE tor_process_get_stdout_pipe(process_handle_t *process_handle);
 475 #else
 476 FILE *tor_process_get_stdout_pipe(process_handle_t *process_handle);
 477 #endif
 478
 479 #ifdef _WIN32
 480 struct smartlist_t *
 481 tor_get_lines_from_handle(HANDLE *handle,
 482                           enum stream_status *stream_status);
 483 #else
 484 struct smartlist_t *
 485 tor_get_lines_from_handle(FILE *handle,
 486                           enum stream_status *stream_status);
 487 #endif
 488
 489 int tor_terminate_process(process_handle_t *process_handle);
 490 void tor_process_handle_destroy(process_handle_t *process_handle,
 491                                 int also_terminate_process);
 492
 493 /* ===== Insecure rng */
 494 typedef struct tor_weak_rng_t {
 495   uint32_t state;
 496 } tor_weak_rng_t;
 497
 498 #define TOR_WEAK_RNG_INIT {383745623}
 499 #define TOR_WEAK_RANDOM_MAX (INT_MAX)
 500 void tor_init_weak_random(tor_weak_rng_t *weak_rng, unsigned seed);
 501 int32_t tor_weak_random(tor_weak_rng_t *weak_rng);
 502 int32_t tor_weak_random_range(tor_weak_rng_t *rng, int32_t top);
 503 /** Randomly return true according to <b>rng</b> with probability 1 in
 504  * <b>n</b> */
 505 #define tor_weak_random_one_in_n(rng, n) (0==tor_weak_random_range((rng),(n)))
 506
 507 #ifdef UTIL_PRIVATE
 508 /* Prototypes for private functions only used by util.c (and unit tests) */
 509
 510 int format_hex_number_for_helper_exit_status(unsigned int x, char *buf,
 511                                              int max_len);
 512 int format_helper_exit_status(unsigned char child_state,
 513                               int saved_errno, char *hex_errno);
 514
 515 /* Space for hex values of child state, a slash, saved_errno (with
 516    leading minus) and newline (no null) */
 517 #define HEX_ERRNO_SIZE (sizeof(char) * 2 + 1 + \
 518                         1 + sizeof(int) * 2 + 1)
 519 #endif
 520
 521 const char *libor_get_digests(void);
 522
 523 #endif
 524