From 5d099a4fe1b846fcc987259b19cb5c8922ffd399 Mon Sep 17 00:00:00 2001
From: adnano <me@adnano.co>
Date: Sun, 27 Sep 2020 23:58:45 -0400
Subject: [PATCH] Only generate certificates after CertificateRequired

---
 client.go                 | 24 ++++++++++++++++++------
 examples/client/client.go |  1 -
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/client.go b/client.go
index 37b1b6d..94b4363 100644
--- a/client.go
+++ b/client.go
@@ -6,6 +6,7 @@ import (
 	"crypto/x509"
 	"errors"
 	"io/ioutil"
+	"log"
 	"net"
 	"net/url"
 	"strconv"
@@ -188,7 +189,7 @@ type Client struct {
 	CertificateStore CertificateStore
 
 	// GetCertificate, if not nil, will be called to determine which certificate
-	// (if any) should be used for a request.
+	// to use when the server responds with CertificateRequired.
 	GetCertificate func(hostname string, store CertificateStore) *tls.Certificate
 
 	// TrustCertificate, if not nil, will be called to determine whether the
@@ -204,11 +205,6 @@ func (c *Client) Send(req *Request) (*Response, error) {
 		InsecureSkipVerify: true,
 		MinVersion:         tls.VersionTLS12,
 		GetClientCertificate: func(info *tls.CertificateRequestInfo) (*tls.Certificate, error) {
-			if c.GetCertificate != nil {
-				if cert := c.GetCertificate(req.Hostname(), c.CertificateStore); cert != nil {
-					return cert, nil
-				}
-			}
 			if req.Certificate != nil {
 				return req.Certificate, nil
 			}
@@ -261,6 +257,22 @@ func (c *Client) Send(req *Request) (*Response, error) {
 	}
 	// Store connection information
 	resp.TLS = conn.ConnectionState()
+
+	// Resend the request with a certificate if the server responded
+	// with CertificateRequired
+	if resp.Status == StatusCertificateRequired {
+		// Check to see if a certificate was already provided to prevent an infinite loop
+		if req.Certificate != nil {
+			return resp, nil
+		}
+		if c.GetCertificate != nil {
+			if cert := c.GetCertificate(req.Hostname(), c.CertificateStore); cert != nil {
+				req.Certificate = cert
+				return c.Send(req)
+			}
+		}
+	}
+
 	return resp, nil
 }
 
diff --git a/examples/client/client.go b/examples/client/client.go
index a64365f..e8a16be 100644
--- a/examples/client/client.go
+++ b/examples/client/client.go
@@ -89,7 +89,6 @@ func sendRequest(req *gmi.Request) error {
 		}
 		// Handle relative redirects
 		red.URL = req.URL.ResolveReference(red.URL)
-		fmt.Println(red.URL, red.Host)
 		return sendRequest(red)
 	case gmi.StatusClassTemporaryFailure:
 		return fmt.Errorf("Temporary failure: %s", resp.Meta)