RSA 4096 in C++ how to apply?

Question

C++ / C#

Hello, I have a public key in the form:

<BitStrength>4096</BitStrength><RSAKeyValue><Modulus>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</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>

I need to encrypt a string using this public key, I can't find a solution (I don't use OpenSSL or CryptoPP because of the weight). The application must run on Windows XP. Does anyone know a working code?

Answer 1

I don't use OpenSSL or CryptoPP due to weight

Link statically and disable all unnecessary algorithms at the configuration stage.

Answer 2

I don't use OpenSSL or CryptoPP due to weight

Then you will have to implement long arithmetic for numbers at least 4096 bits long. Then implement the RSA algorithm itself.