From 9915e0e2b18308cfb87c59449b2ed3c7697f259a Mon Sep 17 00:00:00 2001
From: Fabian Wiesel <fabian.wiesel@sap.com>
Date: Fri, 11 Mar 2022 11:26:51 +0100
Subject: [PATCH] Parse f5vpn urls

After an endpoint-inspection, the webpage forwards
to an f5vpn url, which can now be passed on to
gof5 to extract the session-id itself.

Only missing to be a proper f5vpn handler is
logging
---
 cmd/gof5/main.go     |  6 ++++++
 pkg/client/client.go | 48 +++++++++++++++++++++++++++++++++++++++++++-
 pkg/client/http.go   |  5 ++++-
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/cmd/gof5/main.go b/cmd/gof5/main.go
index 2f88f03..8ce211b 100644
--- a/cmd/gof5/main.go
+++ b/cmd/gof5/main.go
@@ -61,6 +61,12 @@ func main() {
 		fatal(err)
 	}
 
+	if flag.NArg() > 0 {
+		if err := client.UrlHandlerF5Vpn(&opts, flag.Arg(0)); err != nil {
+			fatal(err)
+		}
+	}
+
 	if err := client.Connect(&opts); err != nil {
 		fatal(err)
 	}
diff --git a/pkg/client/client.go b/pkg/client/client.go
index 716a012..b3ebe48 100644
--- a/pkg/client/client.go
+++ b/pkg/client/client.go
@@ -32,9 +32,55 @@ type Options struct {
 	Sel           bool
 	Version       bool
 	ProfileIndex  int
+	ProfileName   string
 	Renegotiation tls.RenegotiationSupport
 }
 
+func UrlHandlerF5Vpn(opts *Options, s string) error {
+	u, err := url.Parse(s)
+	if err != nil {
+		return err
+	}
+
+	if u.Scheme != "f5-vpn" {
+		return fmt.Errorf("invalid scheme %v expected f5-vpn", u.Scheme)
+	}
+
+	m, err := url.ParseQuery(u.RawQuery)
+	if err != nil {
+		return err
+	}
+
+	resourceTypes := m["resourcetype"]
+	resourceNames := m["resourcename"]
+	if len(resourceTypes) == len(resourceNames) {
+		for i := range resourceTypes {
+			if resourceTypes[i] == "network_access" {
+				opts.ProfileName = resourceNames[i]
+				break
+			}
+		}
+	}
+
+	opts.Server = m["server"][0]
+	tokenUrl := fmt.Sprintf("%s://%s:%s/vdesk/get_sessid_for_token.php3", m["protocol"][0], opts.Server, m["port"][0])
+	request, err := http.NewRequest(http.MethodGet, tokenUrl, nil)
+	if err != nil {
+		return err
+	}
+	otc := m["otc"]
+	request.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+	request.Header.Add("X-Access-Session-Token", otc[len(otc)-1])
+
+	response, err := http.DefaultClient.Do(request)
+	if err != nil {
+		return err
+	}
+
+	opts.SessionID = response.Header.Get("X-Access-Session-ID")
+	return nil
+}
+
 func Connect(opts *Options) error {
 	if opts.Server == "" {
 		fmt.Print("Enter server address: ")
@@ -152,7 +198,7 @@ func Connect(opts *Options) error {
 		return fmt.Errorf("wrong response code on profiles get: %d", resp.StatusCode)
 	}
 
-	profile, err := parseProfile(resp.Body, opts.ProfileIndex)
+	profile, err := parseProfile(resp.Body, opts.ProfileIndex, opts.ProfileName)
 	if err != nil {
 		return fmt.Errorf("failed to parse VPN profiles: %s", err)
 	}
diff --git a/pkg/client/http.go b/pkg/client/http.go
index 4df8ffe..331b207 100644
--- a/pkg/client/http.go
+++ b/pkg/client/http.go
@@ -307,7 +307,7 @@ func login(c *http.Client, server string, username, password *string) error {
 	return nil
 }
 
-func parseProfile(reader io.ReadCloser, profileIndex int) (string, error) {
+func parseProfile(reader io.ReadCloser, profileIndex int, profileName string) (string, error) {
 	var profiles config.Profiles
 	dec := xml.NewDecoder(reader)
 	err := dec.Decode(&profiles)
@@ -319,6 +319,9 @@ func parseProfile(reader io.ReadCloser, profileIndex int) (string, error) {
 	if profiles.Type == "VPN" {
 		prfls := make([]string, len(profiles.Favorites))
 		for i, p := range profiles.Favorites {
+			if profileName != "" && profileName == p.Name {
+				profileIndex = i
+			}
 			prfls[i] = fmt.Sprintf("%d:%s", i, p.Name)
 		}
 		log.Printf("Found F5 VPN profiles: %q", prfls)