C++ @programming.dev xolatgames @programming.dev 4d ago

Create a string that contains random characters

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!

16 comments

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?
- Asking to do a homework.
  
  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
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;
- 🤭
- that's cheating
  
  (also, it won't work on systems without curl installed)
  
  (or without internet access)
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)
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.
- 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
  
  Oh good I had forgotten that part!
- What's the best encryption algorithm in your opinion?
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.

16 comments