Line data    Source code

       1             : /* Copyright (c) 2001-2004, Roger Dingledine.
       2             :  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
       3             :  * Copyright (c) 2007-2021, The Tor Project, Inc. */
       4             : /* See LICENSE for licensing information */
       5             : 
       6             : /**
       7             :  * \file recommend_pkg.c
       8             :  * \brief Code related to the recommended-packages subsystem.
       9             :  *
      10             :  * Currently unused.
      11             :  **/
      12             : 
      13             : #include "core/or/or.h"
      14             : #include "feature/dirauth/recommend_pkg.h"
      15             : 
      16             : /** Return true iff <b>line</b> is a valid RecommendedPackages line.
      17             :  */
      18             : /*
      19             :   The grammar is:
      20             : 
      21             :     "package" SP PACKAGENAME SP VERSION SP URL SP DIGESTS NL
      22             : 
      23             :       PACKAGENAME = NONSPACE
      24             :       VERSION = NONSPACE
      25             :       URL = NONSPACE
      26             :       DIGESTS = DIGEST | DIGESTS SP DIGEST
      27             :       DIGEST = DIGESTTYPE "=" DIGESTVAL
      28             : 
      29             :       NONSPACE = one or more non-space printing characters
      30             : 
      31             :       DIGESTVAL = DIGESTTYPE = one or more non-=, non-" " characters.
      32             : 
      33             :       SP = " "
      34             :       NL = a newline
      35             : 
      36             :  */
      37             : int
      38          66 : validate_recommended_package_line(const char *line)
      39             : {
      40          66 :   const char *cp = line;
      41             : 
      42             : #define WORD()                                  \
      43             :   do {                                          \
      44             :     if (*cp == ' ')                             \
      45             :       return 0;                                 \
      46             :     cp = strchr(cp, ' ');                       \
      47             :     if (!cp)                                    \
      48             :       return 0;                                 \
      49             :   } while (0)
      50             : 
      51          66 :   WORD(); /* skip packagename */
      52          63 :   ++cp;
      53          63 :   WORD(); /* skip version */
      54          58 :   ++cp;
      55          58 :   WORD(); /* Skip URL */
      56          54 :   ++cp;
      57             : 
      58             :   /* Skip digesttype=digestval + */
      59          54 :   int n_entries = 0;
      60          72 :   while (1) {
      61          63 :     const char *start_of_word = cp;
      62          63 :     const char *end_of_word = strchr(cp, ' ');
      63          63 :     if (! end_of_word)
      64          54 :       end_of_word = cp + strlen(cp);
      65             : 
      66          63 :     if (start_of_word == end_of_word)
      67             :       return 0;
      68             : 
      69          61 :     const char *eq = memchr(start_of_word, '=', end_of_word - start_of_word);
      70             : 
      71          61 :     if (!eq)
      72             :       return 0;
      73          59 :     if (eq == start_of_word)
      74             :       return 0;
      75          59 :     if (eq == end_of_word - 1)
      76             :       return 0;
      77          59 :     if (memchr(eq+1, '=', end_of_word - (eq+1)))
      78             :       return 0;
      79             : 
      80          58 :     ++n_entries;
      81          58 :     if (0 == *end_of_word)
      82             :       break;
      83             : 
      84           9 :     cp = end_of_word + 1;
      85             :   }
      86             : 
      87             :   /* If we reach this point, we have at least 1 entry. */
      88             :   tor_assert(n_entries > 0);
      89             :   return 1;
      90             : }