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Hi! ✌️ I need to generate some string in C++ with random characters that can use all letters from "a" to "z" (include capital letters), and all numbers from 0 to 9 there.

And for examples this should looks somehow like this:

SnHXAsOC5XDYLgiKM5ly

Also I want to encrypt that string then by itself:

SnHXAsOC5XDYLgiKM5ly encrypt with SnHXAsOC5XDYLgiKM5ly key.

So, how can I do this in C++? 🤔

Thanks in advance!

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[-] bunitor@lemmy.eco.br 4 points 3 days ago

you can do this in pretty much any language. have you tried anything and need help or you're just asking us to do your homework for you?

[-] xolatgames@programming.dev 1 points 2 days ago
[-] bunitor@lemmy.eco.br 2 points 2 days ago

honest advice: it's fine to ask for help online, but not putting any effort into solving your own problems before you do is disrespectful

[-] pelya@lemmy.world 3 points 3 days ago
FILE *f = popen("curl 'https://www.random.org/passwords/?num=1&len=12&format=plain&rnd=new'", "r");
char s[14];
fread(s, 1, sizeof(s), f);
s[13] = 0;
[-] bunitor@lemmy.eco.br 2 points 3 days ago

that's cheating

(also, it won't work on systems without curl installed)

[-] lambalicious@lemmy.sdf.org 1 points 3 days ago

(or without internet access)

[-] Oisteink@feddit.nl 2 points 3 days ago

This is not doable in c++ unfortunately. Its an old case that’s only doable in f# or turbo pascal because of string handling and cryptography export rules (and possibly copy right)

[-] lambalicious@lemmy.sdf.org 1 points 3 days ago* (last edited 3 days ago)

There are various ways to solve the first part and they're pretty generic, the only "C++-specific" part is whether you'll want to build the string step by step (adding characters) or build in one go then modify (build a prearranged string, for example of a specific size, then modify as needed).

To solve the second part we (you) also need to know the encryption algorithm. "Encrypt" is quite a generic word.

[-] xolatgames@programming.dev 2 points 2 days ago* (last edited 2 days ago)

Let's solve the first part then.

But I guess that @herzenschein already suggested me a solution...

You could take inspiration from Theodore Tso’s pwgen: https://github.com/tytso/pwgen

[-] lambalicious@lemmy.sdf.org 1 points 2 days ago

Oh good I had forgotten that part!

[-] xolatgames@programming.dev 1 points 2 days ago

What's the best encryption algorithm in your opinion?

[-] herzenschein@pawb.social 1 points 3 days ago

You could take inspiration from Theodore Tso's pwgen: https://github.com/tytso/pwgen

It's a Unix utility in C commonly used on Linux and FreeBSD to make truly random passwords. It's the first thing I thought of when reading this.

[-] xolatgames@programming.dev 1 points 2 days ago

Thanks so much! 👍🏼

[-] xolatgames@programming.dev 1 points 2 days ago

But thanks to you! 😄

this post was submitted on 29 Jun 2025
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