Clash.Meta/component/ca/keypair.go

93 lines
2.9 KiB
Go

package ca
import (
"crypto"
"crypto/ecdsa"
"crypto/ed25519"
"crypto/elliptic"
"crypto/rand"
"crypto/rsa"
"crypto/tls"
"crypto/x509"
"encoding/pem"
"fmt"
"math/big"
)
type Path interface {
Resolve(path string) string
}
// LoadTLSKeyPair loads a TLS key pair from the provided certificate and private key data or file paths, supporting fallback resolution.
// Returns a tls.Certificate and an error, where the error indicates issues during parsing or file loading.
// If both certificate and privateKey are empty, generates a random TLS RSA key pair.
// Accepts a Path interface for resolving file paths when necessary.
func LoadTLSKeyPair(certificate, privateKey string, path Path) (tls.Certificate, error) {
if certificate == "" && privateKey == "" {
var err error
certificate, privateKey, _, err = NewRandomTLSKeyPair(KeyPairTypeRSA)
if err != nil {
return tls.Certificate{}, err
}
}
cert, painTextErr := tls.X509KeyPair([]byte(certificate), []byte(privateKey))
if painTextErr == nil {
return cert, nil
}
if path == nil {
return tls.Certificate{}, painTextErr
}
certificate = path.Resolve(certificate)
privateKey = path.Resolve(privateKey)
cert, loadErr := tls.LoadX509KeyPair(certificate, privateKey)
if loadErr != nil {
return tls.Certificate{}, fmt.Errorf("parse certificate failed, maybe format error:%s, or path error: %s", painTextErr.Error(), loadErr.Error())
}
return cert, nil
}
type KeyPairType string
const (
KeyPairTypeRSA KeyPairType = "rsa"
KeyPairTypeP256 KeyPairType = "p256"
KeyPairTypeP384 KeyPairType = "p384"
KeyPairTypeEd25519 KeyPairType = "ed25519"
)
// NewRandomTLSKeyPair generates a random TLS key pair based on the specified KeyPairType and returns it with a SHA256 fingerprint.
// Note: Most browsers do not support KeyPairTypeEd25519 type of certificate, and utls.UConn will also reject this type of certificate.
func NewRandomTLSKeyPair(keyPairType KeyPairType) (certificate string, privateKey string, fingerprint string, err error) {
var key crypto.Signer
switch keyPairType {
case KeyPairTypeRSA:
key, err = rsa.GenerateKey(rand.Reader, 2048)
case KeyPairTypeP256:
key, err = ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
case KeyPairTypeP384:
key, err = ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
case KeyPairTypeEd25519:
_, key, err = ed25519.GenerateKey(rand.Reader)
default: // fallback to KeyPairTypeRSA
key, err = rsa.GenerateKey(rand.Reader, 2048)
}
if err != nil {
return
}
template := x509.Certificate{SerialNumber: big.NewInt(1)}
certDER, err := x509.CreateCertificate(rand.Reader, &template, &template, key.Public(), key)
if err != nil {
return
}
privBytes, err := x509.MarshalPKCS8PrivateKey(key)
if err != nil {
return
}
fingerprint = CalculateFingerprint(certDER)
privateKey = string(pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: privBytes}))
certificate = string(pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: certDER}))
return
}