Using Rsa Public Key To Encrypt A String

I've been working on my expressjs project, but now I've run into a dead end. I need to encrypt a string with a specific modulus and exponent. I should probably mention that I reall

Solution 1:

The PEM format is a Base64-encoded version of the DER format. You can use OpenSSL to help you build up DER, and then output PEM. I gave this answer to another question, which has some Ruby code that outputs a PEM-formatted file, given just the modulus and exponent. This should lead you to a solution.