/*
* lmd5.c
* MD5 library for Lua 5.0 based on Rivest's API
* Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br>
* 12 Nov 2008 20:09:42
* This code is hereby placed in the public domain.
*/

#include <stdio.h>

#include "lmd5.h"

#include "lua.h"
#include "lauxlib.h"

#define MYVERSION	MYNAME " library for " LUA_VERSION " / Nov 2008 / "\
			"using " AUTHOR
#define MYTYPE		MYNAME " context"

static MD5_CTX *Pget(lua_State *L, int i)
{
 return luaL_checkudata(L,i,MYTYPE);
}

static MD5_CTX *Pnew(lua_State *L)
{
 MD5_CTX *c=lua_newuserdata(L,sizeof(MD5_CTX));
 luaL_getmetatable(L,MYTYPE);
 lua_setmetatable(L,-2);
 return c;
}

static int Lnew(lua_State *L)			/** new() */
{
 MD5_CTX *c=Pnew(L);
 MD5Init(c);
 return 1;
}

static int Lclone(lua_State *L)			/** clone(c) */
{
 MD5_CTX *c=Pget(L,1);
 MD5_CTX *d=Pnew(L);
 *d=*c;
 return 1;
}

static int Lreset(lua_State *L)			/** reset(c) */
{
 MD5_CTX *c=Pget(L,1);
 MD5Init(c);
 return 0;
}

static int Lupdate(lua_State *L)		/** update(c,s) */
{
 size_t l;
 MD5_CTX *c=Pget(L,1);
 const char *s=luaL_checklstring(L,2,&l);
 MD5Update(c,s,l);
 return 0;
}

static int Ldigest(lua_State *L)		/** digest(c or s,[raw]) */
{
 unsigned char digest[N];
 if (lua_isuserdata(L,1))
 {
  MD5_CTX c=*Pget(L,1);
  MD5Final(digest,&c);
 }
 else
 {
  size_t l;
  const char *s=luaL_checklstring(L,1,&l);
  MD5_CTX c;
  MD5Init(&c);
  MD5Update(&c,s,l);
  MD5Final(digest,&c);
 }
 if (lua_toboolean(L,2))
  lua_pushlstring(L,digest,sizeof(digest));
 else
 {
  char hex[2*N+1];
  int i;
  for (i=0; i<N; i++) sprintf(hex+2*i,"%02x",digest[i]);
  lua_pushlstring(L,hex,sizeof(hex)-1);
 }
 return 1;
}

static int Ltostring(lua_State *L)		/** tostring(c) */
{
 MD5_CTX *c=Pget(L,1);
 lua_pushfstring(L,"%s %p",MYTYPE,(void*)c);
 return 1;
}

static const luaL_reg R[] =
{
	{ "clone",	Lclone	},
	{ "digest",	Ldigest	},
	{ "new",	Lnew	},
	{ "reset",	Lreset	},
	{ "tostring",	Ltostring},
	{ "update",	Lupdate	},
	{ NULL,		NULL	}
};

LUALIB_API int luaopen_md5(lua_State *L)
{
 luaL_newmetatable(L,MYTYPE);
 lua_pushvalue(L,-1);
 luaL_openlib(L,NULL,R,0);
 lua_pushliteral(L,"version");			/** version */
 lua_pushliteral(L,MYVERSION);
 lua_settable(L,-3);
 lua_pushliteral(L,"__index");
 lua_pushvalue(L,-2);
 lua_settable(L,-3);
 lua_pushliteral(L,"__tostring");
 lua_pushliteral(L,"tostring");
 lua_gettable(L,-3);
 lua_settable(L,-3);
 lua_setglobal(L,MYNAME);
 return 1;
}