From ddd990b645aafea2c6ddd8d85160518f6530d567 Mon Sep 17 00:00:00 2001
From: Samuel Hawksby-Robinson <samuel@samyoul.com>
Date: Tue, 3 May 2022 15:50:40 +0100
Subject: [PATCH] Added basic client functionality

---
 server/client.go     | 46 ++++++++++++++++++++++++++++++++++++++++++++
 server/connection.go |  5 +++++
 server/ips_test.go   | 35 +++++++++++++--------------------
 3 files changed, 64 insertions(+), 22 deletions(-)
 create mode 100644 server/client.go

diff --git a/server/client.go b/server/client.go
new file mode 100644
index 000000000..147119a8e
--- /dev/null
+++ b/server/client.go
@@ -0,0 +1,46 @@
+package server
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"net/http"
+	"net/url"
+)
+
+type Client struct {
+	*http.Client
+
+	baseAddress *url.URL
+	certPEM []byte
+}
+
+func NewClient(c *ConnectionParams) (*Client, error) {
+	u, certPem, err := c.Generate()
+	if err != nil {
+		return nil, err
+	}
+
+	rootCAs, err := x509.SystemCertPool()
+	if err != nil {
+		return nil, err
+	}
+
+	if ok := rootCAs.AppendCertsFromPEM(certPem); !ok {
+		return nil, fmt.Errorf("failed to append certPem to rootCAs")
+	}
+
+	tr := &http.Transport{
+		TLSClientConfig: &tls.Config{
+			MinVersion:         tls.VersionTLS12,
+			InsecureSkipVerify: false, // MUST BE FALSE
+			RootCAs:            rootCAs,
+		},
+	}
+
+	return &Client{
+		Client:      &http.Client{Transport: tr},
+		baseAddress: u,
+		certPEM:     certPem,
+	}, nil
+}
diff --git a/server/connection.go b/server/connection.go
index 5a261e317..7aeb6db8c 100644
--- a/server/connection.go
+++ b/server/connection.go
@@ -182,6 +182,11 @@ func (cp *ConnectionParams) validateServerMode() error {
 
 // Generate returns a *url.URL and encoded pem.Block generated from ConnectionParams set fields
 func (cp *ConnectionParams) Generate() (*url.URL, []byte, error) {
+	err := cp.validate()
+	if err != nil {
+		return nil, nil, err
+	}
+
 	u := &url.URL{
 		Scheme: "https",
 		Host:   fmt.Sprintf("%s:%d", cp.netIP, cp.port),
diff --git a/server/ips_test.go b/server/ips_test.go
index 5ecae865a..7e31a7aef 100644
--- a/server/ips_test.go
+++ b/server/ips_test.go
@@ -4,8 +4,6 @@ import (
 	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
-	"crypto/tls"
-	"crypto/x509"
 	"encoding/hex"
 	"io/ioutil"
 	"net/http"
@@ -29,6 +27,16 @@ func testHandler(t *testing.T) func(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func makeThingToSay() (string, error) {
+	b := make([]byte, 32)
+	_, err := rand.Read(b)
+	if err != nil {
+		return "", err
+	}
+
+	return hex.EncodeToString(b), nil
+}
+
 func TestGetOutboundIPWithFullServerE2e(t *testing.T) {
 	// Get 3 key components for tls.cert generation
 	// 1) Ephemeral private key
@@ -68,30 +76,13 @@ func TestGetOutboundIPWithFullServerE2e(t *testing.T) {
 	err = ccp.FromString(qr)
 	require.NoError(t, err)
 
-	u, certPem, err := ccp.Generate()
+	c, err := NewClient(ccp)
 	require.NoError(t, err)
 
-	rootCAs, err := x509.SystemCertPool()
+	thing, err := makeThingToSay()
 	require.NoError(t, err)
 
-	ok := rootCAs.AppendCertsFromPEM(certPem)
-	require.True(t, ok)
-
-	tr := &http.Transport{
-		TLSClientConfig: &tls.Config{
-			MinVersion:         tls.VersionTLS12,
-			InsecureSkipVerify: false, // MUST BE FALSE, or the test is meaningless
-			RootCAs:            rootCAs,
-		},
-	}
-	client := &http.Client{Transport: tr}
-
-	b := make([]byte, 32)
-	_, err = rand.Read(b)
-	require.NoError(t, err)
-	thing := hex.EncodeToString(b)
-
-	response, err := client.Get(u.String() + "/hello?say=" + thing)
+	response, err := c.Get(c.baseAddress.String() + "/hello?say=" + thing)
 	require.NoError(t, err)
 
 	defer response.Body.Close()