TUN-2943: Copy certutil from edge into cloudflared

certutil/certutil.go

@@ -0,0 +1,94 @@
+package certutil
+
+import (
+	"crypto/x509"
+	"encoding/json"
+	"encoding/pem"
+	"fmt"
+	"strings"
+)
+
+type namedTunnelToken struct {
+	ZoneID     string `json:"zoneID"`
+	AccountID  string `json:"accountID"`
+	ServiceKey string `json:"serviceKey"`
+}
+
+type OriginCert struct {
+	PrivateKey interface{}
+	Cert       *x509.Certificate
+	ZoneID     string
+	ServiceKey string
+	AccountID  string
+}
+
+func DecodeOriginCert(blocks []byte) (*OriginCert, error) {
+	if len(blocks) == 0 {
+		return nil, fmt.Errorf("Cannot decode empty certificate")
+	}
+	originCert := OriginCert{}
+	block, rest := pem.Decode(blocks)
+	for {
+		if block == nil {
+			break
+		}
+		switch block.Type {
+		case "PRIVATE KEY":
+			if originCert.PrivateKey != nil {
+				return nil, fmt.Errorf("Found multiple private key in the certificate")
+			}
+			// RSA private key
+			privateKey, err := x509.ParsePKCS8PrivateKey(block.Bytes)
+			if err != nil {
+				return nil, fmt.Errorf("Cannot parse private key")
+			}
+			originCert.PrivateKey = privateKey
+		case "CERTIFICATE":
+			if originCert.Cert != nil {
+				return nil, fmt.Errorf("Found multiple certificates in the certificate")
+			}
+			cert, err := x509.ParseCertificates(block.Bytes)
+			if err != nil {
+				return nil, fmt.Errorf("Cannot parse certificate")
+			} else if len(cert) > 1 {
+				return nil, fmt.Errorf("Found multiple certificates in the certificate")
+			}
+			originCert.Cert = cert[0]
+		case "WARP TOKEN", "ARGO TUNNEL TOKEN":
+			if originCert.ZoneID != "" || originCert.ServiceKey != "" {
+				return nil, fmt.Errorf("Found multiple tokens in the certificate")
+			}
+			// The token is a string,
+			// Try the newer JSON format
+			ntt := namedTunnelToken{}
+			if err := json.Unmarshal(block.Bytes, &ntt); err == nil {
+				originCert.ZoneID = ntt.ZoneID
+				originCert.ServiceKey = ntt.ServiceKey
+				originCert.AccountID = ntt.AccountID
+			} else {
+				// Try the older format, where the zoneID and service key are seperated by
+				// a new line character
+				token := string(block.Bytes)
+				s := strings.Split(token, "\n")
+				if len(s) != 2 {
+					return nil, fmt.Errorf("Cannot parse token")
+				}
+				originCert.ZoneID = s[0]
+				originCert.ServiceKey = s[1]
+			}
+		default:
+			return nil, fmt.Errorf("Unknown block %s in the certificate", block.Type)
+		}
+		block, rest = pem.Decode(rest)
+	}
+
+	if originCert.PrivateKey == nil {
+		return nil, fmt.Errorf("Missing private key in the certificate")
+	} else if originCert.Cert == nil {
+		return nil, fmt.Errorf("Missing certificate in the certificate")
+	} else if originCert.ZoneID == "" || originCert.ServiceKey == "" {
+		return nil, fmt.Errorf("Missing token in the certificate")
+	}
+
+	return &originCert, nil
+}