How to verify if a public key matched private key signature?

Question

How does one verify that a public key matched private key?

On start of the application, 2048-bit RSA keys are loaded from base64 PEM encoded string. I wish to verify that the keys are valid and that they match before continuing. The signing and verification is done by the underlining library I'm using.

I could sign and verify dummy data, but I am looking for alternative solutions.

Starter playground: https://play.golang.org/p/tsB8Yp-xs47

Answer 1

The solution is pretty simple

func verifyKeyPair(private, public string) bool {
    // Handle errors here
    block, _ := pem.Decode([]byte(rsaPrivateKey))
    key, _ := x509.ParsePKCS1PrivateKey(block.Bytes)
    pubBlock, _ := pem.Decode([]byte(rsaPublicKey))
    pubKey, _ := x509.ParsePKIXPublicKey(pubBlock.Bytes)
    return key.PublicKey.Equal(pubKey)
}

https://play.golang.org/p/tR6Ns0wDrlN