添加 github.com/pion/dtls 代码

dtls-2.0.9/examples/util/util.go

@@ -0,0 +1,154 @@
+// Package util provides auxiliary utilities used in examples
+package util
+
+import (
+	"bufio"
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const bufSize = 8192
+
+var (
+	errBlockIsNotPrivateKey  = errors.New("block is not a private key, unable to load key")
+	errUnknownKeyTime        = errors.New("unknown key time in PKCS#8 wrapping, unable to load key")
+	errNoPrivateKeyFound     = errors.New("no private key found, unable to load key")
+	errBlockIsNotCertificate = errors.New("block is not a certificate, unable to load certificates")
+	errNoCertificateFound    = errors.New("no certificate found, unable to load certificates")
+)
+
+// Chat simulates a simple text chat session over the connection
+func Chat(conn io.ReadWriter) {
+	go func() {
+		b := make([]byte, bufSize)
+
+		for {
+			n, err := conn.Read(b)
+			Check(err)
+			fmt.Printf("Got message: %s\n", string(b[:n]))
+		}
+	}()
+
+	reader := bufio.NewReader(os.Stdin)
+
+	for {
+		text, err := reader.ReadString('\n')
+		Check(err)
+
+		if strings.TrimSpace(text) == "exit" {
+			return
+		}
+
+		_, err = conn.Write([]byte(text))
+		Check(err)
+	}
+}
+
+// Check is a helper to throw errors in the examples
+func Check(err error) {
+	switch e := err.(type) {
+	case nil:
+	case (net.Error):
+		if e.Temporary() {
+			fmt.Printf("Warning: %v\n", err)
+			return
+		}
+
+		fmt.Printf("net.Error: %v\n", err)
+		panic(err)
+	default:
+		fmt.Printf("error: %v\n", err)
+		panic(err)
+	}
+}
+
+// LoadKeyAndCertificate reads certificates or key from file
+func LoadKeyAndCertificate(keyPath string, certificatePath string) (*tls.Certificate, error) {
+	privateKey, err := LoadKey(keyPath)
+	if err != nil {
+		return nil, err
+	}
+
+	certificate, err := LoadCertificate(certificatePath)
+	if err != nil {
+		return nil, err
+	}
+
+	certificate.PrivateKey = privateKey
+
+	return certificate, nil
+}
+
+// LoadKey Load/read key from file
+func LoadKey(path string) (crypto.PrivateKey, error) {
+	rawData, err := ioutil.ReadFile(filepath.Clean(path))
+	if err != nil {
+		return nil, err
+	}
+
+	block, _ := pem.Decode(rawData)
+	if block == nil || !strings.HasSuffix(block.Type, "PRIVATE KEY") {
+		return nil, errBlockIsNotPrivateKey
+	}
+
+	if key, err := x509.ParsePKCS1PrivateKey(block.Bytes); err == nil {
+		return key, nil
+	}
+
+	if key, err := x509.ParsePKCS8PrivateKey(block.Bytes); err == nil {
+		switch key := key.(type) {
+		case *rsa.PrivateKey, *ecdsa.PrivateKey:
+			return key, nil
+		default:
+			return nil, errUnknownKeyTime
+		}
+	}
+
+	if key, err := x509.ParseECPrivateKey(block.Bytes); err == nil {
+		return key, nil
+	}
+
+	return nil, errNoPrivateKeyFound
+}
+
+// LoadCertificate Load/read certificate(s) from file
+func LoadCertificate(path string) (*tls.Certificate, error) {
+	rawData, err := ioutil.ReadFile(filepath.Clean(path))
+	if err != nil {
+		return nil, err
+	}
+
+	var certificate tls.Certificate
+
+	for {
+		block, rest := pem.Decode(rawData)
+		if block == nil {
+			break
+		}
+
+		if block.Type != "CERTIFICATE" {
+			return nil, errBlockIsNotCertificate
+		}
+
+		certificate.Certificate = append(certificate.Certificate, block.Bytes)
+		rawData = rest
+	}
+
+	if len(certificate.Certificate) == 0 {
+		return nil, errNoCertificateFound
+	}
+
+	return &certificate, nil
+}