KeysSetting.h

   1 /*
   2  * Copyright (c) 2008, Dave Korn.
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     A copy of the GNU General Public License can be found at
  10  *     http://www.gnu.org/
  11  *
  12  *  This is the header for the ExtraKeysSetting class, which persists and reads
  13  * in (and saves) extra public DSA signing keys for the verification process.
  14  * It stores them all in a contiguous memory buffer.  Each is one line of
  15  * ASCII text terminated by LF.  THERE IS NO NUL-TERMINATION HERE, TAKE CARE!
  16  * The buffer is sized to the exact size of the content including the terminating
  17  * LF of the last entry.  There is no zero after it.  After reading the file,
  18  * any partial last line is truncated.
  19  *
  20  * Written by Dave Korn <dave.korn.cygwin@gmail.com>
  21  *
  22  */
  23
  24 #ifndef SETUP_KEYSSETTING_H
  25 #define SETUP_KEYSSETTING_H
  26
  27 #include <string>
  28
  29 class ExtraKeysSetting
  30 {
  31   private:
  32     char *keybuffer;
  33     size_t bufsize;
  34     size_t numkeys;
  35     static ExtraKeysSetting *global;
  36   public:
  37     // Loads keys from last-extrakeys
  38     ExtraKeysSetting ();
  39     // Saves them back again.
  40     ~ExtraKeysSetting ();
  41     static ExtraKeysSetting& instance () {return *global;}
  42
  43   private:
  44     // Extend (or shrink) allocated buffer.  Leaves it in a
  45     // potentially invalid state until count_keys is called
  46     // (or the bufsize is made valid by filling it up and
  47     // the numkeys count adjusted likewise).
  48     void realloc (size_t newbufsize);
  49     // Count keys and size buffer after loading.
  50     size_t count_keys (void);
  51     // Add a key without testing for existence
  52     void add_unique_key (const char *key);
  53
  54   public:
  55     // Number of keys in buffer.
  56     size_t num_keys (void);
  57     // Get pointer to LF-terminated Nth. key string and len.
  58     const char *get_key (size_t num, size_t *size);
  59     // Add a key to the buffer (if not already present).
  60     void add_key (const char *key);
  61     // Empty the buffer.
  62     void flush (void);
  63 };
  64
  65 #endif /* SETUP_CONNECTIONSETTING_H */