Graphic digit verification code

Graphical digit verification Code graphical digit verification Code:
/*

* Filename: authpage. php

*/



Srand (double) microtime () * 1000000 );



// Verify that the user input is consistent with the verification code

If (isset ($ _ POST ['authinput'])

{


If (strcmp ($ _ POST ['authnum'], $ _ POST ['authinput']) = 0)

Echo "verification successful! ";

Else

Echo "verification failed! ";

}



// Generate a new four-digit integer verification code

While ($ authnum = rand () % 10000) <1000 );

?>



Bytes -------------------------------------------------------------------------------------------------------------

/*

* Filename: authimg. php

*/
// Generate a verification code Image
Header ("Content-type: image/PNG ");

Srand (double) microtime () * 1000000 );

$ Im = imagecreate (58,28 );

$ Black = ImageColorAllocate ($ im, 0, 0 );

$ White = ImageColorAllocate ($ im, 255,255,255 );

$ Gray = ImageColorAllocate ($ im, 200,200,200 );

Imagefill ($ im, 68, 30, $ gray );



// Print the four-digit integer verification code into the image

Imagestring ($ im, 5, 10, 8, $ HTTP_GET_VARS ['authnum'], $ white );



For ($ I = 0; $ I <50; $ I ++) // add interference pixels

{

Imagesetpixel ($ im, rand () % 70, rand () % 30, $ gray );

}



ImagePNG ($ im );

ImageDestroy ($ im );

?>