chore: refresh gramsrv public release

internal/sfu/cert.go

@@ -0,0 +1,43 @@
+package sfu
+
+import (
+	"crypto/sha256"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/hex"
+	"fmt"
+	"strings"
+
+	"github.com/pion/dtls/v3/pkg/crypto/selfsign"
+)
+
+// newDTLSCertificate 生成进程级自签证书（DTLS 身份不靠 CA，靠信令面下发的指纹）。
+func newDTLSCertificate() (tls.Certificate, string, error) {
+	cert, err := selfsign.GenerateSelfSigned()
+	if err != nil {
+		return tls.Certificate{}, "", fmt.Errorf("sfu: self-signed cert: %w", err)
+	}
+	fp, err := certificateFingerprint(cert.Certificate[0])
+	if err != nil {
+		return tls.Certificate{}, "", err
+	}
+	return cert, fp, nil
+}
+
+// certificateFingerprint 计算 RFC 4572 风格 sha-256 指纹（"AA:BB:..."）。
+func certificateFingerprint(der []byte) (string, error) {
+	if _, err := x509.ParseCertificate(der); err != nil {
+		return "", fmt.Errorf("sfu: parse cert: %w", err)
+	}
+	sum := sha256.Sum256(der)
+	parts := make([]string, len(sum))
+	for i, b := range sum {
+		parts[i] = strings.ToUpper(hex.EncodeToString([]byte{b}))
+	}
+	return strings.Join(parts, ":"), nil
+}
+
+// normalizeFingerprint 去除大小写/分隔差异后比较用。
+func normalizeFingerprint(fp string) string {
+	return strings.ToUpper(strings.ReplaceAll(strings.TrimSpace(fp), ":", ""))
+}