MOD: refactored picseal class to be static only

libs/jpg_bin.py

@@ -49,8 +49,8 @@ class JpgBin:
     self.prev_mstr = "DUH!"
     self.prev_imgData = False
 
-    self.jpg_fp  = JpgFingerprint()
-    self.picseal = None
+    self.jpg_fp   = JpgFingerprint()
+    self.importSig = None
 
   #
   # check for JPG file type marker
@@ -278,13 +278,12 @@ class JpgBin:
     ps_hdr_size = rec_hdr+len(JpgPicSeal.picseal_marker)
     remain_buf = self.data_len-(self.data_idx+ps_hdr_size)
     if (remain_buf > ps_hdr_size):
-      self.picseal = JpgPicSeal()
-      if (self.picseal.isPicSeal(self.data_buf[self.data_idx+rec_hdr:self.data_idx+ps_hdr_size])):
+      if (JpgPicSeal.isPicSeal(self.data_buf[self.data_idx+rec_hdr:self.data_idx+ps_hdr_size])):
         #
         # calculate size, check buffer, maybe read more bytes from file
         #
         buf = self.__getBuf()
-        retval = self.picseal.deserialize(buf)
+        self.importSig = JpgPicSeal.deserialize(buf)
         return True
     return False
 

libs/jpg_bin_w.py

@@ -18,10 +18,7 @@ class JpgBinWrite:
   #
   def writeJpgPicSealPub(self, crypto_sig, fp):
     self.__writeJpgHeader()
-   
-    ps = JpgPicSeal(crypto_sig)
-    ps.writePub(self.fhw)
-
+    JpgPicSeal.writePub(self.fhw, crypto_sig)
     self.__writeJpgImg(fp)
   
   #
@@ -29,10 +26,7 @@ class JpgBinWrite:
   #
   def writeJpgPicSealPvt(self, crypto_sig, fp):
     self.__writeJpgHeader()
-
-    ps = JpgPicSeal(crypto_sig)
-    ps.writePvt(self.fhw)
-
+    JpgPicSeal.writePvt(self.fhw, crypto_sig)
     self.__writeJpgImg(fp)
 
 

libs/jpg_picseal.py

@@ -23,19 +23,14 @@ class JpgPicSeal:
   pvt_marker = b'\x02'
 
 
-  def __init__(self, sig=None):
-    if (sig):
-      self.sig = sig
-    else:
-      self.sig = Signature()
-    self.sig_data = None
-    
+  def __init__(self):
+    pass    
 
   #
   # READ
   #
 
-  def isPicSeal(self, buf):
+  def isPicSeal(buf):
     if (buf == JpgPicSeal.picseal_marker):
       return True
     return False
@@ -43,26 +38,27 @@ class JpgPicSeal:
   #
   # [size:2|picseal:7|type:1|sig:512|key:550] == 1072
   #
-  def deserialize(self, buf):
+  def deserialize(buf):
+    sig = Signature()
     retval = False
 
     # read type 0x01 is public key, 0x02 private key
     try:
       if (buf[9] == ord(JpgPicSeal.pub_marker)):
-        self.sig.importPubKey(buf[522:])
+        sig.importPubKey(buf[522:])
         print("*** *** ***")
         print("*** Public Key Import Sucessful")
         print("*** *** ***")
       else:
-        self.sig.importPvtKey(buf[522:])
+        sig.importPvtKey(buf[522:])
         print("*** *** ***")
         print("*** Private Key Import Sucessful")
         print("*** *** ***")
-      retval = True
+      return sig
     except Exception as ex:
       logging.debug(ex)
 
-    return retval
+    return None
 
 
   #
@@ -79,23 +75,23 @@ class JpgPicSeal:
   #
 
   #
-  def serilize(self, fname):
+  def serilize(fname):
     pass
   #
   # input is the Crypto Sig class
   #
-  def writePub(self, fhw):
-    self.__writeData(fhw, self.sig.sig_data, self.sig.getPubKeyDER(), JpgPicSeal.pub_marker)
+  def writePub(fhw, sig):
+    JpgPicSeal.__writeData(fhw, sig.sig_data, sig.getPubKeyDER(), JpgPicSeal.pub_marker)
 
   #
   # input is the Crypto Sig class
   #
-  def writePvt(self, fhw):
-    self.__writeData(fhw, self.sig.sig_data, self.sig.getPvtKeyDER(), JpgPicSeal.pvt_marker)
+  def writePvt(fhw, sig):
+    JpgPicSeal.__writeData(fhw, sig.sig_data, sig.getPvtKeyDER(), JpgPicSeal.pvt_marker)
 
 
   #
-  def __writeData(self, fhw, sig_data, keyder, pubpvt):
+  def __writeData(fhw, sig_data, keyder, pubpvt):
     # must include 2 bytes for length too, plus 1 for the key type
     size = 3
     size += len(JpgPicSeal.picseal_marker)