Logo Search packages:      
Sourcecode: paperkey version File versions  Download package

restore.c

/*
 * Copyright (C) 2007 David Shaw <dshaw@jabberwocky.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
static const char RCSID[]="$Id: restore.c 341 2007-09-24 20:15:06Z dshaw $";

#include <config.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <ctype.h>
#include "packets.h"
#include "output.h"
#include "parse.h"
#include "restore.h"

struct key
{
  unsigned char fpr[20];
  struct packet *packet;
  struct key *next;
};

static struct key *
extract_keys(struct packet *packet)
{
  struct key *key=NULL;
  size_t idx=1;

  /* Check the version */
  if(packet->len && packet->buf[0]!=0)
    {
      fprintf(stderr,"Cannot handle secrets file version %d\n",
            packet->buf[0]);
      return NULL;
    }

  while(idx<packet->len)
    {
      /* 1+20+2 == version + fingerprint + length */
      if(idx+1+20+2<=packet->len)
      {
        if(packet->buf[idx]==4)
          {
            unsigned int len;
            struct key *newkey;

            newkey=xmalloc(sizeof(*newkey));
            newkey->next=NULL;

            idx++;
            memcpy(newkey->fpr,&packet->buf[idx],20);

            idx+=20;

            len =packet->buf[idx++]<<8;
            len|=packet->buf[idx++];

            if(idx+len<=packet->len)
            {
              newkey->packet=append_packet(NULL,&packet->buf[idx],len);
              idx+=len;
            }
            else
            {
              fprintf(stderr,"Warning: Short data in secret image\n");
              free(newkey);
              break;
            }

            newkey->next=key;
            key=newkey;
          }
        else
          {
            fprintf(stderr,"Warning: Corrupt data in secret image\n");
            break;
          }
      }
      else
      {
        fprintf(stderr,"Warning: Short header in secret image\n");
        break;
      }
    }
  
  return key;
}

static void
free_keys(struct key *key)
{
  while(key)
    {
      struct key *keytmp=key;
      free_packet(key->packet);
      key=key->next;
      free(keytmp);
    }
}

int
restore(FILE *pubring,FILE *secrets,
      enum data_type input_type,const char *outname)
{
  struct packet *secret;

  if(input_type==AUTO)
    {
      int test=fgetc(secrets);

      if(test==EOF)
      {
        fprintf(stderr,"Unable to check type of secrets file\n");
        return 1;
      }
      else if(isascii(test) && isprint(test))
      input_type=BASE16;
      else
      input_type=RAW;

      ungetc(test,secrets);
    }

  secret=read_secrets_file(secrets,input_type);
  if(secret)
    {
      struct packet *pubkey;
      struct key *keys;
      int did_pubkey=0;

      /* Build a list of all keys.  We need to do this since the
       public key we are transforming might have the subkeys in a
       different order than (or not match subkeys at all with) our
       secret data. */

      keys=extract_keys(secret);
      if(keys)
      {
        output_start(outname,RAW,NULL);

        while((pubkey=parse(pubring,0,0)))
          {
            unsigned char ptag;

            if(pubkey->type==6 || pubkey->type==14)
            {
              /* Public key or subkey */
              unsigned char fpr[20];
              struct key *keyidx;

              if(pubkey->type==6 && did_pubkey)
                break;

              calculate_fingerprint(pubkey,pubkey->len,fpr);

              /* Do we have a secret key that matches? */
              for(keyidx=keys;keyidx;keyidx=keyidx->next)
                {
                  if(memcmp(fpr,keyidx->fpr,20)==0)
                  {
                    if(pubkey->type==6)
                      {
                        ptag=0xC5;
                        did_pubkey=1;
                      }
                    else
                      ptag=0xC7;

                    /* Match, so create a secret key. */
                    output_bytes(&ptag,1);
                    output_openpgp_length(pubkey->len
                                    +keyidx->packet->len);
                    output_packet(pubkey);
                    output_packet(keyidx->packet);
                  }
                }
            }
            else if(pubkey->type==13 && did_pubkey)
            {
              /* Copy the usual user ID, sigs, etc, so the key is
                 well-formed */
              ptag=0xC0|pubkey->type;
              output_bytes(&ptag,1);
              output_openpgp_length(pubkey->len);
              output_packet(pubkey);
            }

            free_packet(pubkey);
          }

        free_keys(keys);
      }
      else
      {
        fprintf(stderr,"Unable to parse secret data\n");
        return 1;
      }
    }
  else
    {
      fprintf(stderr,"Unable to read secrets file\n");
      return 1;
    }

  return 0;
}

Generated by  Doxygen 1.6.0   Back to index