+ void tdes_2key_enc(void* out, const void* in, size_t length, const void* key){
+
+       if( length % 8 ) return; 
+       
+       uint8_t* tin = (uint8_t*) in;
+       uint8_t* tout = (uint8_t*) out;
+       
+       while( length > 0 )
+       {
+               des_enc(tout,  tin, (uint8_t*)key + 0);
+               des_dec(tout, tout, (uint8_t*)key + 8);
+               des_enc(tout, tout, (uint8_t*)key + 0);
+               
+               tin  += 8;
+               tout += 8;
+               length -= 8;
+       }
+ }
+ 
+ void tdes_2key_dec(void* out, const void* in, size_t length, const void* key){
+       
+       if( length % 8 ) return; 
+
+       uint8_t* tin = (uint8_t*) in;
+       uint8_t* tout = (uint8_t*) out;
+       
+       while( length > 0 )
+       {
+               des_dec(tout,  tin, (uint8_t*)key + 0);
+               des_enc(tout, tout, (uint8_t*)key + 8);
+               des_dec(tout, tout, (uint8_t*)key + 0);          
+
+               tin  += 8;
+               tout += 8;
+               length -= 8;
+       }
+ }
+