t1io.c

source code: Covert TXT to PDF

  unsigned long off_save;
  unsigned long filesize;
  
  off_save=lseek( f->fd, 0, SEEK_CUR);
  filesize=lseek( f->fd, 0, SEEK_END);
  lseek( f->fd, off_save, SEEK_SET);
  return( filesize);
}



/* -------------------------------------------------------------- */
int T1Ungetc(c, f)   /* Put back one character */
  int c;
  F_FILE *f;         /* Stream descriptor */
{
  if (c != EOF) {
    f->ungotc = c;
    f->flags |= UNGOTTENC;  /* set flag */
    f->flags &= ~FIOEOF;    /* reset EOF */
  }
  return c;
} /* end Ungetc */
 
/* -------------------------------------------------------------- */
int T1Read(buffP, size, n, f)  /* Read n items into caller's buffer */
  char *buffP;       /* Buffer to be filled */
  int   size;        /* Size of each item */
  int   n;           /* Number of items to read */
  F_FILE *f;         /* Stream descriptor */
{
  int bytelen, cnt, i;
  F_char *p = (F_char *)buffP;
  int  icnt;         /* Number of characters to read */
 
  if (f->b_base == NULL) return 0;  /* closed */
  icnt = (size!=1)?n*size:n;  /* Number of bytes we want */
 
  if (f->flags & UNGOTTENC) { /* there is an ungotten c */
    f->flags &= ~UNGOTTENC;
    *(p++) = f->ungotc;
    icnt--; bytelen = 1;
  }
  else bytelen = 0;
 
  while (icnt > 0) {
    /* First use any bytes we have buffered in the stream buffer */
    if ((cnt=f->b_cnt) > 0) {
      if (cnt > icnt) cnt = icnt;
      for (i=0; i<cnt; i++) *(p++) = *(f->b_ptr++);
      f->b_cnt -= cnt;
      icnt -= cnt;
      bytelen += cnt;
    }
 
    if ((icnt == 0) || (f->flags & FIOEOF)) break;
 
    f->b_cnt = T1Fill(f);
  }
  return ((size!=1)?bytelen/size:bytelen);
} /* end Read */
 
/* -------------------------------------------------------------- */
int T1Close(f)       /* Close the file */
  F_FILE *f;         /* Stream descriptor */
{
  if (f->b_base == NULL) return 0;  /* already closed */
  f->b_base = NULL;  /* no valid stream */
  return close(f->fd);
} /* end Close */
 

/* -------------------------------------------------------------- */
F_FILE *T1eexec(f)   /* Initialization */
  F_FILE *f;         /* Stream descriptor */
{
  int i;
  int H;
  
  unsigned char *p;
  unsigned char randomP[8];
 
  r = 55665;  /* initial key */
  asc = 1;    /* indicate ASCII form */

#ifdef DEBUG_DECRYPTION
  printf("T1eexec(1): first 20 bytes=%.20s, b_cnt=%d\n", f->b_ptr, f->b_cnt);
#endif
  
  /* Consume the 4 random bytes, determining if we are also to
     ASCIIDecodeHex as we process our input.  (See pages 63-64
     of the Adobe Type 1 Font Format book.)  */

  /* Skipping over initial white space chars has been removed since
     it could lead to unprocessable pfb-fonts if accindentally the
     first cipher text byte was of the class HWHITE_SPACE.
     Instead, we just read ahead, this should suffice for any
     Type 1 font program. (RMz, 08/02/1998) */

  /* If ASCII, the next 7 chars are guaranteed consecutive */
  randomP[0] = getc(f);  /* store first non white space char */
  fread(randomP+1, 1, 3, f);  /* read 3 more, for a total of 4 */
  /* store first four chars */
  for (i=0,p=randomP; i<4; i++) {  /* Check 4 valid ASCIIEncode chars */
    if (HighHexP[*p++] > LAST_HDIGIT) {  /* non-ASCII byte */
      asc = 0;
      break;
    }
  }
  if (asc) {  /* ASCII form, convert first eight bytes to binary */
    fread(randomP+4, 1, 4, f);  /* Need four more */
    for (i=0,p=randomP; i<4; i++) {  /* Convert */
      H = HighHexP[*p++];
      randomP[i] = H | LowHexP[*p++];
    }
  }
  
  /* Adjust our key */
  for (i=0,p=randomP; i<4; i++) {
    r = (*p++ + r) * c1 + c2;
  }

  /* Decrypt the remaining buffered bytes */
  f->b_cnt = T1Decrypt(f->b_ptr, f->b_cnt);
  Decrypt = 1;
  
#ifdef DEBUG_DECRYPTION
  printf("T1eexec(2): first 120 bytes=%.120s, b_cnt=%d\n", f->b_ptr, f->b_cnt);
#endif
  
  return (feof(f))?NULL:f;
} /* end eexec */
 
/* -------------------------------------------------------------- */
STATIC int T1Decrypt(p, len)
  unsigned char *p;
  int len;
{
  int n;
  int H=0, L=0;
  unsigned char *inp = p;
  unsigned char *tblP;
 
#ifdef DEBUG_DECRYPTION
  printf("T1_Decrypt(): called with len=%d\n",len);
#endif
  if (asc) {
    if (haveextrach) {
      H = extrach;
      tblP = LowHexP;
    }
    else tblP = HighHexP;
    for (n=0; len>0; len--) {
      L = tblP[*inp++];
#ifdef DEBUG_DECRYPTION
      printf("L=0x%X, %d, inp=%c (%d)\n", L,L, *(inp-1), *(inp-1));
#endif
      if (L == HWHITE_SPACE) {
#ifdef DEBUG_DECRYPTION	
	printf("continue\n");
#endif
	continue;
      }
      if (L > LAST_HDIGIT) {
#ifdef DEBUG_DECRYPTION
	printf("L=0x%X, --> break\n", L);
#endif
	break;
      }
      
      if (tblP == HighHexP) { /* Got first hexit value */
        H = L;
        tblP = LowHexP;
      } else { /* Got second hexit value; compute value and store it */
        n++;
        tblP = HighHexP;
        H |= L;
        /* H is an int, 0 <= H <= 255, so all of this will work */
        *p++ = H ^ (r >> 8);
        r = (H + r) * c1 + c2;
      }
    }
    if (tblP != HighHexP) {  /* We had an odd number of hexits */
      extrach = H;
      haveextrach = 1;
    } else haveextrach = 0;
#ifdef DEBUG_DECRYPTION
    printf("T1_Decrypt(): Decrypted %d bytes\n",n);
#endif
    return n;
  } else {
    for (n = len; n>0; n--) {
      H = *inp++;
      *p++ = H ^ (r >> 8);
      r = (H + r) * c1 + c2;
    }
    return len;
  }
} /* end Decrypt */
 
/* -------------------------------------------------------------- */
/* This function has been adapted to support pfb-files with multiple
   data segments */
STATIC int T1Fill(f) /* Refill stream buffer */
  F_FILE *f;         /* Stream descriptor */
{
  int rc,i;
  static unsigned char hdr_buf[6];

  if (starthex80){ /* we have a pfb-file -> be aware of pfb-blocks */
    if ( pfbblocklen-accu >= F_BUFSIZ){
      /* fill the buffer */
      rc = read(f->fd, f->b_base, F_BUFSIZ);
      bytecnt+=rc;
      accu +=rc;
    }
    else{
      if (pfbblocklen-accu>0){
	/* read the remaining of the pfb-block ... */
	rc = read(f->fd, f->b_base, pfbblocklen-accu);
	bytecnt +=rc;
	accu +=rc;
	/* ... and examine the next header */
	i=read(f->fd, hdr_buf, 6);
	bytecnt +=i;
	pfbblocklen=0;
	pfbblocklen += hdr_buf[2]&0xFF  ;
	pfbblocklen += (hdr_buf[3] & 0xFF)  <<8;
	pfbblocklen += (hdr_buf[4] & 0xFF)  <<16;
	pfbblocklen += (hdr_buf[5] & 0xFF)  <<24;
#ifdef DEBUG_PFB_BLOCKS	
	printf("t1io: New segment, length=%d, type=%d\n",
	       pfbblocklen, hdr_buf[1]);
#endif	
	accu=0;
      }
      else{
	/* We are at the beginning of a new block ->
	   examine header */
	i=read(f->fd, hdr_buf, 6);
	pfbblocklen=0;
	pfbblocklen += hdr_buf[2]&0xFF  ;
	pfbblocklen += (hdr_buf[3] & 0xFF)  <<8;
	pfbblocklen += (hdr_buf[4] & 0xFF)  <<16;
	pfbblocklen += (hdr_buf[5] & 0xFF)  <<24;
#ifdef DEBUG_PFB_BLOCKS	
	printf("t1io: New segment, length=%d, type=%d\n",
	       pfbblocklen, hdr_buf[1]);
#endif
	accu=0;
	/* header read, now fill the buffer */
	if (pfbblocklen-accu >= F_BUFSIZ){
	  rc = read(f->fd, f->b_base, F_BUFSIZ);
	  accu +=rc;
	}
	else{
	  /* we have the unusual case that the pfb-block size is
	     shorter than F_BUFSIZ -> Read this block only */
	  rc = read(f->fd, f->b_base, pfbblocklen);
	  accu +=rc;
	}
      }
    }
  }
  else{
    /* We have a pfa-file -> read straight ahead and fill buffer */
    rc = read(f->fd, f->b_base, F_BUFSIZ);
  }
  
  /* propagate any error or eof to current file */
  if (rc <= 0) {
    if (rc == 0)    /* means EOF */
      f->flags |= FIOEOF;
    else {
      f->error = (short)-rc;
      f->flags |= FIOERROR;
      rc = 0;
    }
  }

  f->b_ptr = f->b_base;
#ifdef DEBUG_DECRYPTION
  printf("T1_Fill(): read %d bytes\n", rc);
#endif
  
  if (Decrypt){
    rc = T1Decrypt(f->b_base, rc);
#ifdef DEBUG_DECRYPTION
    printf("T1_Fill(): decrypted %d bytes\n", rc);
#endif
  }
  
  return rc;
} /* end Fill */


void T1io_reset(void)
{
  pfbblocklen=0;
  accu=0;
  starthex80=0;
  eexec_startOK=0;
  eexec_endOK=0;
  in_eexec=0;
}