keys.go

package main

import (
    "crypto/rand"
    "crypto/rsa"
    "crypto/x509"
    "encoding/pem"
)

// Generate new RSA keypair
func Generate() *rsa.PrivateKey {
    priv, err := rsa.GenerateKey(rand.Reader, Bits)

    if err != nil {
        panic(err)
    }

    return priv
}

// Stringify private key
func Stringify(priv *rsa.PrivateKey) string {
    privateKeyDer := x509.MarshalPKCS1PrivateKey(priv)
    privateKeyBlock := pem.Block{
        Type:    "RSA PRIVATE KEY",
        Headers: nil,
        Bytes:   privateKeyDer,
    }

    return string(pem.EncodeToMemory(&privateKeyBlock))
}

// DecodeKey
func DecodeKey(key []byte) (*rsa.PrivateKey, error) {
    block, _ := pem.Decode([]byte(key))

    priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)

    return priv, err
}