implemented --lower-level auto for client. better makefile

encrypt.cpp

@@ -12,10 +12,10 @@
 
 static int8_t zero_iv[]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,   0,0,0,0};//this prog use zero iv,you should make sure first block of data contains a random/nonce data
 /****
- * important!
- * why zero iv + nonce first data block is secure?
+ * security of zero_iv + nonce first data block
  * https://crypto.stackexchange.com/questions/5421/using-cbc-with-a-fixed-iv-and-a-random-first-plaintext-block
 ****/
+
 unordered_map<int, const char *> auth_mode_tostring = {{auth_none, "none"}, {auth_md5, "md5"}, {auth_crc32, "crc32"},{auth_simple,"simple"}};
 unordered_map<int, const char *> cipher_mode_tostring={{cipher_none,"none"},{cipher_aes128cbc,"aes128cbc"},{cipher_xor,"xor"}};