Php Generate Random Key String
Do you have to generate a public key every time. I was working on a project recently that required unique API keys to be generated for clients connecting to the server. For various reasons, I settled on the style of license key you commonly see for software packages. You know, the kind you always had to read off the back of a CD case and type in when installing the application. Like H8OV7-HNTB5-JLLOH-W8FG2
.
It’s fairly easy to write such a function. The basic idea is to loop around four times—once for each segment—and have a nested loop that runs five times, picking a random character each time. Here’s what I came up with:
Nov 14, 2019 10 Ways to Generate a Random Password from the Linux Command Line Lowell Heddings @lowellheddings Updated November 14, 2019, 2:44pm EDT One of the great things about Linux is that you can do the same thing hundreds of different ways—even something as simple as generating a random password can be accomplished with dozens of different commands. All you're doing there is generating a default random number (so PHP doesn't have to parse any arguments) and chopping off the piece that's useful to you (using a bitwise operation which is faster than even basic math). Nov 21, 2018 If you want to generate random hexadecimal strings in PHP, you can also use either the md5($string, $rawoutput) or the sha1($string, $rawoutput) function. Both of them will generate hashes of a given input string. You will keep getting unique hashes as long as the input is unique.
The $tokens
string contains the characters that are valid in the key, so the loop can pick from it. The $segment_chars
and $num_segments
variables are the number of characters in a segment and the number of segments in the key, respectively. $key_string
is an empty string that the loop will add the characters into.
Php Generate Random Key String Lights
The first for loop runs four times, assuming the desired result is four segments in the key. The inner loop picks a character out of $tokens
at random each time it goes around. (PHP strings are also arrays, with the each character having its own numerical offset.) The characters are tacked onto the $segment
string.
Php Create Random String
Then the segment is joined with the $key_string
, and a dash character is applied if the loop isn’t on the final segment yet. End result: something like H8OV7-HNTB5-JLLOH-W8FG2
.
Php Random Function
Now how can you make sure the key is unique when it’s generated?
Steam
You generate a new key string with the function, check to see if it exists in your database, and lather/rinse/repeat until that is no longer the case. Usually you won’t have collisions too often, so it will only need to run once. I’m too lazy to figure out the probability, but considering there are 52,521,875 possible combinations for one 5-character segment…you’re probably not going to run into performance issues anytime soon. And if you do, just add another segment onto your key strings.