Files
mihomo/component/ca/fingerprint.go

77 lines
2.5 KiB
Go

package ca
import (
"bytes"
"crypto/sha256"
"crypto/x509"
"encoding/hex"
"fmt"
"strings"
"time"
)
// NewFingerprintVerifier returns a function that verifies whether a certificate's SHA-256 fingerprint matches the given one.
func NewFingerprintVerifier(fingerprint string, time func() time.Time) (func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error, error) {
switch fingerprint {
case "chrome", "firefox", "safari", "ios", "android", "edge", "360", "qq", "random", "randomized": // WTF???
return nil, fmt.Errorf("`fingerprint` is used for TLS certificate pinning. If you need to specify the browser fingerprint, use `client-fingerprint`")
}
fingerprint = strings.TrimSpace(strings.Replace(fingerprint, ":", "", -1))
fpByte, err := hex.DecodeString(fingerprint)
if err != nil {
return nil, fmt.Errorf("fingerprint string decode error: %w", err)
}
if len(fpByte) != 32 {
return nil, fmt.Errorf("fingerprint string length error,need sha256 fingerprint")
}
return func(rawCerts [][]byte, verifiedChains [][]*x509.Certificate) error {
// ssl pining
for i, rawCert := range rawCerts {
hash := sha256.Sum256(rawCert)
if bytes.Equal(fpByte, hash[:]) {
if i > 0 {
// When the fingerprint matches a non-leaf certificate,
// the certificate chain validity is verified using the certificate as the trusted root certificate.
//
// Currently, we do not verify that the SNI matches the certificate's DNS name,
// but we do verify the validity of the child certificate,
// including the issuance time and whether the child certificate was issued by the parent certificate.
certs := make([]*x509.Certificate, i+1) // stop at i
for j := range certs {
cert, err := x509.ParseCertificate(rawCerts[j])
if err != nil {
return err
}
certs[j] = cert
}
opts := x509.VerifyOptions{
Roots: x509.NewCertPool(),
Intermediates: x509.NewCertPool(),
}
if time != nil {
opts.CurrentTime = time()
}
opts.Roots.AddCert(certs[i])
for _, cert := range certs[1:] {
opts.Intermediates.AddCert(cert)
}
_, err := certs[0].Verify(opts)
return err
}
return nil
}
}
return errNotMatch
}, nil
}
// CalculateFingerprint computes the SHA-256 fingerprint of the given DER-encoded certificate and returns it as a hex string.
func CalculateFingerprint(certDER []byte) string {
hash := sha256.Sum256(certDER)
return hex.EncodeToString(hash[:])
}