Drizzled Public API Documentation

md5.cc

00001 /* vim: expandtab:shiftwidth=2:tabstop=2:smarttab: 
00002    Copyright (C) 2006 MySQL AB
00003 
00004    This program is free software; you can redistribute it and/or modify
00005    it under the terms of the GNU General Public License as published by
00006    the Free Software Foundation; version 2 of the License.
00007 
00008    This program is distributed in the hope that it will be useful,
00009    but WITHOUT ANY WARRANTY; without even the implied warranty of
00010    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00011    GNU General Public License for more details.
00012 
00013    You should have received a copy of the GNU General Public License
00014    along with this program; if not, write to the Free Software
00015    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA */
00016 
00017 #include <config.h>
00018 
00019 #include <cstdio>
00020 #include <cstddef>
00021 
00022 #include <gcrypt.h>
00023 
00024 #include <drizzled/charset.h>
00025 #include <drizzled/charset_info.h>
00026 #include <drizzled/function/str/strfunc.h>
00027 #include <drizzled/item/func.h>
00028 #include <drizzled/plugin/function.h>
00029 
00030 using namespace std;
00031 using namespace drizzled;
00032 
00033 class Md5Function : public Item_str_func
00034 {
00035 public:
00036   Md5Function() : Item_str_func() {}
00037   String *val_str(String*);
00038 
00039   void fix_length_and_dec() 
00040   {
00041     max_length= 32;
00042     args[0]->collation.set(
00043       get_charset_by_csname(args[0]->collation.collation->csname,
00044                             MY_CS_BINSORT), DERIVATION_COERCIBLE);
00045   }
00046 
00047   const char *func_name() const 
00048   { 
00049     return "md5"; 
00050   }
00051 
00052   bool check_argument_count(int n) 
00053   { 
00054     return (n == 1); 
00055   }
00056 };
00057 
00058 
00059 String *Md5Function::val_str(String *str)
00060 {
00061   assert(fixed == true);
00062 
00063   String *sptr= args[0]->val_str(str);
00064   if (sptr == NULL || str->alloc(32)) 
00065   {
00066     null_value= true;
00067     return 0;
00068   }
00069 
00070   null_value= false;
00071 
00072   str->set_charset(&my_charset_bin);
00073 
00074   gcry_md_hd_t md5_context;
00075   gcry_md_open(&md5_context, GCRY_MD_MD5, 0);
00076   gcry_md_write(md5_context, sptr->ptr(), sptr->length());  
00077   unsigned char *digest= gcry_md_read(md5_context, 0);
00078 
00079   snprintf((char *) str->ptr(), 33,
00080     "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
00081     digest[0], digest[1], digest[2], digest[3],
00082     digest[4], digest[5], digest[6], digest[7],
00083     digest[8], digest[9], digest[10], digest[11],
00084     digest[12], digest[13], digest[14], digest[15]);
00085   str->length((uint32_t) 32);
00086 
00087   gcry_md_close(md5_context);
00088 
00089   return str;
00090 }
00091 
00092 
00093 plugin::Create_function<Md5Function> *md5udf= NULL;
00094 
00095 static int initialize(module::Context &context)
00096 {
00097   /* Initialize libgcrypt */
00098   if (not gcry_check_version(GCRYPT_VERSION))
00099   {
00100     errmsg_printf(error::ERROR, _("libgcrypt library version mismatch"));
00101     return 1;
00102   }
00103   /* Disable secure memory.  */
00104   gcry_control (GCRYCTL_DISABLE_SECMEM, 0);
00105 
00106   /* Tell Libgcrypt that initialization has completed. */
00107   gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0);
00108 
00109   md5udf= new plugin::Create_function<Md5Function>("md5");
00110   context.add(md5udf);
00111   return 0;
00112 }
00113 
00114 DRIZZLE_DECLARE_PLUGIN
00115 {
00116   DRIZZLE_VERSION_ID,
00117   "md5",
00118   "1.0",
00119   "Stewart Smith",
00120   "UDF for computing md5sum",
00121   PLUGIN_LICENSE_GPL,
00122   initialize, /* Plugin Init */
00123   NULL,   /* depends */
00124   NULL    /* config options */
00125 }
00126 DRIZZLE_DECLARE_PLUGIN_END;