package crypto

import (
	"bytes"
	"compress/flate"
	"compress/zlib"
	"crypto"
	"crypto/rsa"
	"crypto/tls"

	"github.com/lucas-clemente/quic-go/testdata"

	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"
)

var _ = Describe("ProofRsa", func() {
	It("gives correct cert", func() {
		cert := []byte{0xde, 0xca, 0xfb, 0xad}
		certZlib := &bytes.Buffer{}
		z, err := zlib.NewWriterLevelDict(certZlib, flate.BestCompression, certDictZlib)
		Expect(err).ToNot(HaveOccurred())
		z.Write([]byte{0x04, 0x00, 0x00, 0x00})
		z.Write(cert)
		z.Close()
		kd := &rsaSigner{
			config: &tls.Config{
				Certificates: []tls.Certificate{
					tls.Certificate{Certificate: [][]byte{cert}},
				},
			},
		}
		certCompressed, err := kd.GetCertCompressed("")
		Expect(err).ToNot(HaveOccurred())
		Expect(certCompressed).To(Equal(append([]byte{
			0x01, 0x00,
			0x08, 0x00, 0x00, 0x00,
		}, certZlib.Bytes()...)))
	})

	It("gives valid signatures", func() {
		key := testdata.GetTLSConfig().Certificates[0].PrivateKey.(*rsa.PrivateKey).Public().(*rsa.PublicKey)
		kd, err := NewRSASigner(testdata.GetTLSConfig())
		Expect(err).ToNot(HaveOccurred())
		signature, err := kd.SignServerProof("", []byte{'C', 'H', 'L', 'O'}, []byte{'S', 'C', 'F', 'G'})
		Expect(err).ToNot(HaveOccurred())
		// Generated with:
		// ruby -e 'require "digest"; p Digest::SHA256.digest("QUIC CHLO and server config signature\x00" + "\x20\x00\x00\x00" + Digest::SHA256.digest("CHLO") + "SCFG")'
		data := []byte("W\xA6\xFC\xDE\xC7\xD2>c\xE6\xB5\xF6\tq\x9E|<~1\xA33\x01\xCA=\x19\xBD\xC1\xE4\xB0\xBA\x9B\x16%")
		err = rsa.VerifyPSS(key, crypto.SHA256, data, signature, &rsa.PSSOptions{SaltLength: 32})
		Expect(err).ToNot(HaveOccurred())
	})

	Context("retrieving certificate", func() {
		var (
			signer *rsaSigner
			config *tls.Config
			cert   tls.Certificate
		)

		BeforeEach(func() {
			cert = testdata.GetCertificate()
			config = &tls.Config{}
			signer = &rsaSigner{config: config}
		})

		It("uses first certificate in config.Certificates", func() {
			config.Certificates = []tls.Certificate{cert}
			cert, err := signer.getCertForSNI("")
			Expect(err).ToNot(HaveOccurred())
			Expect(cert.PrivateKey).ToNot(BeNil())
			Expect(cert.Certificate[0]).ToNot(BeNil())
		})

		It("uses NameToCertificate entries", func() {
			config.NameToCertificate = map[string]*tls.Certificate{
				"quic.clemente.io": &cert,
			}
			cert, err := signer.getCertForSNI("quic.clemente.io")
			Expect(err).ToNot(HaveOccurred())
			Expect(cert.PrivateKey).ToNot(BeNil())
			Expect(cert.Certificate[0]).ToNot(BeNil())
		})

		It("uses NameToCertificate entries with wildcard", func() {
			config.NameToCertificate = map[string]*tls.Certificate{
				"*.clemente.io": &cert,
			}
			cert, err := signer.getCertForSNI("quic.clemente.io")
			Expect(err).ToNot(HaveOccurred())
			Expect(cert.PrivateKey).ToNot(BeNil())
			Expect(cert.Certificate[0]).ToNot(BeNil())
		})

		It("uses GetCertificate", func() {
			config.GetCertificate = func(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
				Expect(clientHello.ServerName).To(Equal("quic.clemente.io"))
				return &cert, nil
			}
			cert, err := signer.getCertForSNI("quic.clemente.io")
			Expect(err).ToNot(HaveOccurred())
			Expect(cert.PrivateKey).ToNot(BeNil())
			Expect(cert.Certificate[0]).ToNot(BeNil())
		})
	})
})