Signing and Verifying using Golang RSA

rsa_sign.go

// Sign returns a signature made by combining the message and the signers private key
// With the r.Verify function, the signature can be checked.
func (r *RsaIdentity) Sign(msg []byte) (signature []byte, err error) {
	hs := r.getHashSum(msg)
	signature, err := rsa.SignPKCS1v15(rand.Reader, r.private, crypto.SHA256, hs)
	return
}

rsa_verify.go

// Verify checks if a message is signed by a given Public Key
func (r *RsaIdentity) Verify(msg []byte, sig []byte, pk *rsa.PublicKey) error {
	hs := r.getHashSum(msg)
	return rsa.VerifyPKCS1v15(pk, crypto.SHA256, hs, sig)
}