[OpenSER-Devel] postgresql and escaping

[Klaus Darilion]

Hi!

1.

     case DB_BLOB:
         l = VAL_BLOB(_v).len;
         if (*_len < (l * 2 + 3)) {
             LM_ERR("destination buffer too short for blob\n");
             return -7;
         } else {
             *_s++ = '\'';
             tmp_s = (char*)PQescapeByteaConn(CON_CONNECTION(_con), 
(unsigned char*)VAL_STRING(_v),
                     (size_t)l, (size_t*)&tmp_len);
             if(tmp_s==NULL)
             {
                 LM_ERR("PQescapeBytea failed\n");
                 return -7;
             }
             memcpy(_s, tmp_s, tmp_len);
             PQfreemem(tmp_s);
             tmp_len = strlen(_s);
             *(_s + tmp_len) = '\'';
             *(_s + tmp_len + 1) = '\0';
             *_len = tmp_len + 2;
             return 0;
         }
         break;

This means we reserve l*2+3 bytes for the escaped string, but as 
escaping of special characters is done by 3digts octal representation, 
e.g. CR will be converted to \015, this buffer can be too small.

I suggest to make the length check after PQescapeByteaConn and check if 
tmp_len < _len.


2. With postgresql 8.1 the handling of string escaping was changed 
(http://www.postgresql.org/docs/8.1/interactive/release-8-1.html). They 
introduced the E'' syntax and current escaping with \ will be obsolete. 
Thus, maybe we have to update the code to check server version we are 
connected too and thus use the proper escaping.

regards
klaus