src/feature/nodelist/nickname.c

   1 /* Copyright (c) 2001 Matej Pfajfar.
   2  * Copyright (c) 2001-2004, Roger Dingledine.
   3  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   4  * Copyright (c) 2007-2018, The Tor Project, Inc. */
   5 /* See LICENSE for licensing information */
   6
   7 /**
   8  * \file nickname.c
   9  * \brief Check and manipulate relay nicknames.
  10  */
  11
  12 #include "core/or/or.h"
  13 #include "feature/nodelist/nickname.h"
  14
  15 /** Return true iff <b>s</b> is a valid server nickname. (That is, a string
  16  * containing between 1 and MAX_NICKNAME_LEN characters from
  17  * LEGAL_NICKNAME_CHARACTERS.) */
  18 int
  19 is_legal_nickname(const char *s)
  20 {
  21   size_t len;
  22   tor_assert(s);
  23   len = strlen(s);
  24   return len > 0 && len <= MAX_NICKNAME_LEN &&
  25     strspn(s,LEGAL_NICKNAME_CHARACTERS) == len;
  26 }
  27
  28 /** Return true iff <b>s</b> is a valid server nickname or
  29  * hex-encoded identity-key digest. */
  30 int
  31 is_legal_nickname_or_hexdigest(const char *s)
  32 {
  33   if (*s!='$')
  34     return is_legal_nickname(s);
  35   else
  36     return is_legal_hexdigest(s);
  37 }
  38
  39 /** Return true iff <b>s</b> is a valid hex-encoded identity-key
  40  * digest. (That is, an optional $, followed by 40 hex characters,
  41  * followed by either nothing, or = or ~ followed by a nickname, or
  42  * a character other than =, ~, or a hex character.)
  43  */
  44 int
  45 is_legal_hexdigest(const char *s)
  46 {
  47   size_t len;
  48   tor_assert(s);
  49   if (s[0] == '$') s++;
  50   len = strlen(s);
  51   if (len > HEX_DIGEST_LEN) {
  52     if (s[HEX_DIGEST_LEN] == '=' ||
  53         s[HEX_DIGEST_LEN] == '~') {
  54       if (!is_legal_nickname(s+HEX_DIGEST_LEN+1))
  55         return 0;
  56     } else {
  57       return 0;
  58     }
  59   }
  60   return (len >= HEX_DIGEST_LEN &&
  61           strspn(s,HEX_CHARACTERS)==HEX_DIGEST_LEN);
  62 }