libotp.h

   1 /** Practical One-time Pad Library
   2  *
   3  * Created:20080514
   4  * By Jeff Connelly
   5  */
   6
   7 #define MARKER_TO               "to:"
   8 #define MARKER_BEGIN            "--EMOTP_BEGIN--"
   9 #define MARKER_END              "--EMOTP_END--"
  10
  11 #define OFFSET_FILE_EXTENSION   ".off"
  12 #define OFFSET_SIZE             11      /* strlen("4294967296") + 1 */
  13
  14 #define PAD_NAME_LENGTH         4
  15
  16 #define MAX_CONFIG_LINE         1024    /* should be enough, >MAX_PATH */
  17
  18 /* One-time pad. */
  19 typedef struct _PAD {
  20     char *local_filename;
  21     char *name;
  22     FILE *fp;
  23     struct _PAD *next;
  24     /* Use read_offset() and write_offset() to access offset. */
  25 } PAD;
  26
  27
  28 /** Packaged up encrypted message, ready for transport. */
  29 typedef struct _MESSAGE {
  30     unsigned long offset;
  31     PAD *pad;
  32     unsigned long length;
  33     char *cipher_text;
  34 } MESSAGE;
  35
  36 void load_config(char *config_filename);
  37 void show_pads();
  38 FILE *open_offset_file(PAD *p, char *mode);
  39 unsigned long read_offset(PAD *p);
  40 void write_offset(PAD *p, unsigned long offset);
  41 void load_pad(char *local_filename, char *pad_name);
  42 void free_pads();
  43 MESSAGE *unpackage(char *input);
  44 void free_message(MESSAGE *);
  45 char *otp_encrypt(char *input, unsigned int length, char *to, unsigned int *out_length);
  46 unsigned int otp_decrypt(char *input, char **out);
  47