package encrypt

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

// 私钥生成
// openssl genrsa -out rsa_private_key.pem 1024
var privateKey = []byte(`
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
`)

// 公钥: 根据私钥生成
// openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem
var publicKey = []byte(`
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDcGsUIIAINHfRTdMmgGwLrjzfM
NSrtgIf4EGsNaYwmC1GjF/bMh0Mcm10oLhNrKNYCTTQVGGIxuc5heKd1gOzb7bdT
nCDPPZ7oV7p1B9Pud+6zPacoqDz2M24vHFWYY2FbIIJh8fHhKcfXNXOLovdVBE7Z
y682X1+R1lRK8D+vmQIDAQAB
-----END PUBLIC KEY-----
`)

// 加密
func rsaEncrypt(origData []byte) ([]byte, error) {
	//p1 := L.Get(2)
	//publicKey := []byte(L.CheckString(3))
	//isToBase64 := L.ToBool(4)
	//
	//var origData []byte
	//
	//switch p1.Type() {
	//case lua.LTString:
	//	origData = []byte(p1.(lua.LString))
	//case lua.LTByte:
	//	origData = p1.(*lua.LByte).Bytes()
	//}

	//解密pem格式的公钥
	block, _ := pem.Decode(publicKey)
	if block == nil {
		return nil, errors.New("public key error")
	}
	// 解析公钥
	pubInterface, err := x509.ParsePKIXPublicKey(block.Bytes)
	if err != nil {
		return nil, err
	}
	// 类型断言
	pub := pubInterface.(*rsa.PublicKey)
	//加密
	r, e := rsa.EncryptPKCS1v15(rand.Reader, pub, origData)
	if e != nil {
		return nil, e
	}

	return r, nil
}

// 解密
func rsaDecrypt(ciphertext []byte, privateKey []byte) ([]byte, error) {
	//p1 := L.Get(2)
	//var ciphertext []byte
	//privateKey := []byte(L.CheckString(3))
	//
	//isFromBase64 := L.ToBool(4)
	//isToString := L.ToBool(5)
	//
	//switch p1.Type() {
	//case lua.LTString:
	//	if isFromBase64 {
	//		v, e := php.Base64Decode(p1.String())
	//		if e != nil {
	//			L.ArgError(1, "base64 format error")
	//		}
	//		ciphertext = v
	//	} else {
	//		ciphertext = []byte(p1.(lua.LString))
	//	}
	//case lua.LTByte:
	//	ciphertext = p1.(*lua.LByte).Bytes()
	//}

	//解密
	block, _ := pem.Decode(privateKey)
	if block == nil {
		return nil, errors.New("private key error")
	}
	//解析PKCS1格式的私钥
	priv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
	if err != nil {
		return nil, err
	}
	// 解密
	r, e := rsa.DecryptPKCS1v15(rand.Reader, priv, ciphertext)
	if e != nil {
		return nil, e
	}

	return r, nil
}