libotp.c

   1 /** Practical One-time Pad Library
   2  *
   3  * Created:20080514
   4  * By Jeff Connelly
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <sysexits.h>
  10 #include <string.h>
  11
  12 #define MARKER_TO "to:"
  13 #define MARKER_BEGIN "--EMOTP_BEGIN--"
  14 #define MARKER_END "--EMOTP_END--"
  15
  16 /** Packaged up encrypted message, ready for transport. */
  17 typedef struct _PACKAGE
  18 {
  19     unsigned long offset;
  20     char *pad_name;
  21     char *cipher_text;
  22 } PACKAGE;
  23
  24 typedef struct _PAD
  25 {
  26     char *local_filename;
  27     char *name;
  28     unsigned long offset;
  29     FILE *fp;
  30     struct _PAD *next;
  31 } PAD;
  32
  33 PAD *pads = NULL;
  34
  35 void add_pad(PAD *new_pad)
  36 {
  37     if (!pads)
  38     {
  39         pads = new_pad;
  40     }
  41     else
  42     {
  43         PAD *p, *tail;
  44
  45         /* Find tail */
  46         for (p = pads; p; p = p->next)
  47             tail = p;
  48         tail->next = new_pad;
  49     }
  50 }
  51
  52 void show_pads()
  53 {
  54     PAD *p;
  55
  56     printf("h=%.8x\n", (unsigned int)pads);
  57     for (p = pads; p; p = p->next)
  58     {
  59         printf("Pad: %s: %s (next=%.8x)\n", p->name, p->local_filename,
  60                 (unsigned int)p->next);
  61     }
  62 }
  63
  64 void load_pad(char *local_filename)
  65 {
  66     FILE *fp;
  67     PAD *new_pad;
  68
  69     fp = fopen("/Volumes/Not Backed Up/otp/otp-dazzlement", "rb");
  70     if (!fp)
  71     {
  72         perror("fopen");
  73         exit(EXIT_FAILURE);
  74     }
  75
  76     new_pad = malloc(sizeof(PAD));
  77     if (!new_pad)
  78     {
  79         perror("malloc");
  80         exit(EX_UNAVAILABLE);
  81     }
  82
  83     new_pad->local_filename = strdup(local_filename);
  84     new_pad->name = NULL;
  85     /* TODO: new_pad->offset = */
  86     new_pad->fp = fp;
  87     new_pad->next = NULL;
  88
  89     add_pad(new_pad);
  90     add_pad(new_pad);
  91
  92     free(new_pad);
  93 }
  94
  95 int main()
  96 {
  97     load_pad("/Volumes/Not Backed Up/otp/otp-dazzlement");
  98     show_pads();
  99
 100     return 0;
 101 }
 102