Files
quic-go/crypto/proof_rsa.go
2016-05-11 11:40:20 +02:00

119 lines
2.9 KiB
Go

package crypto
import (
"bytes"
"compress/flate"
"compress/zlib"
"crypto"
"crypto/rand"
"crypto/rsa"
"crypto/sha256"
"crypto/tls"
"errors"
"strings"
"github.com/lucas-clemente/quic-go/utils"
)
// rsaSigner stores a key and a certificate for the server proof
type rsaSigner struct {
config *tls.Config
}
// NewRSASigner loads the key and cert from files
func NewRSASigner(tlsConfig *tls.Config) (Signer, error) {
return &rsaSigner{config: tlsConfig}, nil
}
// SignServerProof signs CHLO and server config for use in the server proof
func (kd *rsaSigner) SignServerProof(sni string, chlo []byte, serverConfigData []byte) ([]byte, error) {
cert, err := kd.getCertForSNI(sni)
if err != nil {
return nil, err
}
key, ok := cert.PrivateKey.(*rsa.PrivateKey)
if !ok {
return nil, errors.New("only RSA keys are supported for now")
}
hash := sha256.New()
if len(chlo) > 0 {
// Version >= 31
hash.Write([]byte("QUIC CHLO and server config signature\x00"))
chloHash := sha256.Sum256(chlo)
hash.Write([]byte{32, 0, 0, 0})
hash.Write(chloHash[:])
} else {
hash.Write([]byte("QUIC server config signature\x00"))
}
hash.Write(serverConfigData)
return rsa.SignPSS(
rand.Reader,
key,
crypto.SHA256,
hash.Sum(nil),
&rsa.PSSOptions{SaltLength: 32},
)
}
// GetCertCompressed gets the certificate in the format described by the QUIC crypto doc
func (kd *rsaSigner) GetCertCompressed(sni string) ([]byte, error) {
cert, err := kd.getCertForSNI(sni)
if err != nil {
return nil, err
}
b := &bytes.Buffer{}
b.WriteByte(1) // Entry type compressed
b.WriteByte(0) // Entry type end_of_list
utils.WriteUint32(b, uint32(len(cert.Certificate[0])+4))
gz, err := zlib.NewWriterLevelDict(b, flate.BestCompression, certDictZlib)
if err != nil {
panic(err)
}
lenCert := len(cert.Certificate[0])
gz.Write([]byte{
byte(lenCert & 0xff),
byte((lenCert >> 8) & 0xff),
byte((lenCert >> 16) & 0xff),
byte((lenCert >> 24) & 0xff),
})
gz.Write(cert.Certificate[0])
gz.Close()
return b.Bytes(), nil
}
// GetLeafCert gets the leaf certificate
func (kd *rsaSigner) GetLeafCert(sni string) ([]byte, error) {
cert, err := kd.getCertForSNI(sni)
if err != nil {
return nil, err
}
return cert.Certificate[0], nil
}
func (kd *rsaSigner) getCertForSNI(sni string) (*tls.Certificate, error) {
if kd.config.GetCertificate != nil {
cert, err := kd.config.GetCertificate(&tls.ClientHelloInfo{ServerName: sni})
if err != nil {
return nil, err
}
if cert != nil {
return cert, nil
}
}
if len(kd.config.NameToCertificate) != 0 {
if cert, ok := kd.config.NameToCertificate[sni]; ok {
return cert, nil
}
wildcardSNI := "*" + strings.TrimLeftFunc(sni, func(r rune) bool { return r != '.' })
if cert, ok := kd.config.NameToCertificate[wildcardSNI]; ok {
return cert, nil
}
}
if len(kd.config.Certificates) != 0 {
return &kd.config.Certificates[0], nil
}
return nil, errors.New("no matching certificate found")
}