Files
CanvasArchiver/internal/panopto/downloader.go
2026-02-13 20:42:53 +01:00

326 lines
9.6 KiB
Go

package panopto
import (
"encoding/json"
"fmt"
"io"
"net/http"
"net/http/cookiejar"
"net/url"
"os"
"os/exec"
"path/filepath"
"regexp"
"strings"
"git.directme.in/Joren/CanvasArchiver/internal/config"
"git.directme.in/Joren/CanvasArchiver/internal/utils"
)
func getYoutubeDLCommand() string {
exePath, err := os.Executable()
if err == nil {
dir := filepath.Dir(exePath)
localYtDlp := filepath.Join(dir, "yt-dlp.exe")
if _, err := os.Stat(localYtDlp); err == nil {
return localYtDlp
}
if _, err := os.Stat("yt-dlp.exe"); err == nil {
abs, _ := filepath.Abs("yt-dlp.exe")
return abs
}
}
return "yt-dlp"
}
func DownloadVideo(httpClient *http.Client, accessToken, courseID, modDir, inputURL, title string) {
jar, _ := cookiejar.New(nil)
panoptoClient := &http.Client{
Jar: jar,
CheckRedirect: func(req *http.Request, via []*http.Request) error {
return http.ErrUseLastResponse
},
}
var launchURL string
isDirectLink := false
if strings.Contains(inputURL, "/api/v1/") {
launchURL = inputURL
} else {
isDirectLink = true
launchURL = fmt.Sprintf("%s/api/v1/courses/%s/external_tools/sessionless_launch?id=%s&launch_type=course_navigation",
config.BaseURL, courseID, config.PanoptoID)
}
req, _ := http.NewRequest("GET", launchURL, nil)
req.Header.Set("Authorization", "Bearer "+accessToken)
req.Header.Set("User-Agent", config.UserAgent)
resp, err := httpClient.Do(req)
if err != nil {
fmt.Printf(" [!] Failed to get launch URL: %v\n", err)
return
}
var launchData struct {
URL string `json:"url"`
}
json.NewDecoder(resp.Body).Decode(&launchData)
resp.Body.Close()
if launchData.URL == "" {
fmt.Printf(" [!] No launch URL found (Video skipped)\n")
return
}
bridgeReq, _ := http.NewRequest("GET",
config.BaseURL+"/login/session_token?return_to="+url.QueryEscape(launchData.URL), nil)
bridgeReq.Header.Set("Authorization", "Bearer "+accessToken)
bridgeReq.Header.Set("User-Agent", config.UserAgent)
bResp, _ := httpClient.Do(bridgeReq)
var bridgeData struct {
SessionURL string `json:"session_url"`
}
json.NewDecoder(bResp.Body).Decode(&bridgeData)
bResp.Body.Close()
formResp, err := httpClient.Get(bridgeData.SessionURL)
if err != nil {
return
}
formHTMLBytes, _ := io.ReadAll(formResp.Body)
formResp.Body.Close()
formHTML := string(formHTMLBytes)
if strings.Contains(formHTML, "U hebt geen toegang") || strings.Contains(formHTML, "You do not have access") {
fmt.Printf(" [!] Access denied by Panopto (U hebt geen toegang). Skipping.\n")
return
}
action := utils.ResolveAction(bridgeData.SessionURL, formHTML)
formData := utils.ExtractFormFields(formHTML)
pReq, _ := http.NewRequest("POST", action, strings.NewReader(formData.Encode()))
pReq.Header.Set("Content-Type", "application/x-www-form-urlencoded")
pReq.Header.Set("User-Agent", config.UserAgent)
pReq.Header.Set("Origin", config.BaseURL)
pReq.Header.Set("Referer", config.BaseURL+"/")
pResp, err := panoptoClient.Do(pReq)
if err != nil {
fmt.Printf(" [!] Panopto POST failed: %v\n", err)
return
}
pHtml, _ := io.ReadAll(pResp.Body)
pResp.Body.Close()
var finalURL string
redirectRegex := regexp.MustCompile(`window\.location\.replace\('([^']+)'\)`)
match := redirectRegex.FindStringSubmatch(string(pHtml))
if len(match) > 1 {
finalURL, _ = url.QueryUnescape(strings.ReplaceAll(match[1], `\x`, "%"))
} else {
action2 := utils.ResolveAction(action, string(pHtml))
validData := utils.ExtractFormFields(string(pHtml))
validData.Set("__EVENTTARGET", "checkedLtiPostMessage")
validData.Set("__EVENTARGUMENT", "")
validData.Set("checkedLtiPostMessage", "true")
validData.Set("ltiPostMessage", "")
finalReq, _ := http.NewRequest("POST", action2, strings.NewReader(validData.Encode()))
finalReq.Header.Set("Content-Type", "application/x-www-form-urlencoded")
finalReq.Header.Set("User-Agent", config.UserAgent)
finalReq.Header.Set("Origin", "https://vub.cloud.panopto.eu")
finalReq.Header.Set("Referer", action)
finalResp, err := panoptoClient.Do(finalReq)
if err == nil {
finalHTMLBytes, _ := io.ReadAll(finalResp.Body)
finalHTML := string(finalHTMLBytes)
finalResp.Body.Close()
if finalResp.StatusCode == 302 || finalResp.StatusCode == 303 {
loc, _ := finalResp.Location()
if loc != nil {
finalURL = loc.String()
}
} else {
finalMatch := redirectRegex.FindStringSubmatch(finalHTML)
if len(finalMatch) > 1 {
finalURL, _ = url.QueryUnescape(strings.ReplaceAll(finalMatch[1], `\x`, "%"))
}
}
}
}
// This is for making sure yt-dlp does not auto-start downloading all videos, when access to a hyperlink is denied
if finalURL != "" && !strings.Contains(finalURL, "NonFatalError") {
targetURL := finalURL
if isDirectLink {
targetURL = inputURL
checkReq, _ := http.NewRequest("GET", targetURL, nil)
checkReq.Header.Set("User-Agent", config.UserAgent)
checkResp, err := panoptoClient.Do(checkReq)
if err == nil {
checkResp.Body.Close()
if checkResp.StatusCode == http.StatusFound || checkResp.StatusCode == http.StatusSeeOther {
loc, _ := checkResp.Location()
if loc != nil && (strings.Contains(loc.String(), "Login.aspx") || strings.Contains(loc.String(), "Auth")) {
fmt.Printf(" [!] Video inaccessible (redirects to Login). Skipping to prevent mass download.\n")
return
}
}
}
}
cookieFile := filepath.Join(modDir, ".cookies_temp.txt")
cData := "# Netscape HTTP Cookie File\n"
panoptoDomain, _ := url.Parse("https://vub.cloud.panopto.eu")
for _, cookie := range panoptoClient.Jar.Cookies(panoptoDomain) {
cData += fmt.Sprintf(".vub.cloud.panopto.eu\tTRUE\t/\tTRUE\t0\t%s\t%s\n", cookie.Name, cookie.Value)
}
os.WriteFile(cookieFile, []byte(cData), 0o644)
fmt.Printf(" [*] Downloading video: %s\n", title)
ytCmd := getYoutubeDLCommand()
cmd := exec.Command(ytCmd,
"--no-playlist",
"--cookies", cookieFile,
"--referer", config.BaseURL+"/",
"-P", modDir,
"-o", utils.Sanitize(title)+".%(ext)s",
targetURL)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
if err := cmd.Run(); err != nil {
fmt.Printf(" [!] yt-dlp failed: %v\n", err)
}
os.Remove(cookieFile)
} else {
fmt.Printf(" [!] Handshake failed for: %s\n", title)
}
}
func DownloadMainRecordings(httpClient *http.Client, accessToken, courseID, root string) {
fmt.Println("\n[*] Checking for main Panopto recordings...")
jar, _ := cookiejar.New(nil)
mainClient := &http.Client{Jar: jar}
req, _ := http.NewRequest("GET",
fmt.Sprintf("%s/api/v1/courses/%s/external_tools/sessionless_launch?id=%s&launch_type=course_navigation",
config.BaseURL, courseID, config.PanoptoID), nil)
req.Header.Set("Authorization", "Bearer "+accessToken)
req.Header.Set("User-Agent", config.UserAgent)
resp, _ := httpClient.Do(req)
var launchData struct {
URL string `json:"url"`
}
json.NewDecoder(resp.Body).Decode(&launchData)
resp.Body.Close()
if launchData.URL == "" {
fmt.Println("[!] No main Panopto recordings found")
return
}
bridgeReq, _ := http.NewRequest("GET",
config.BaseURL+"/login/session_token?return_to="+url.QueryEscape(launchData.URL), nil)
bridgeReq.Header.Set("Authorization", "Bearer "+accessToken)
bridgeReq.Header.Set("User-Agent", config.UserAgent)
bResp, _ := httpClient.Do(bridgeReq)
var bridgeData struct {
SessionURL string `json:"session_url"`
}
json.NewDecoder(bResp.Body).Decode(&bridgeData)
bResp.Body.Close()
formResp, _ := mainClient.Get(bridgeData.SessionURL)
formHTML, _ := io.ReadAll(formResp.Body)
formResp.Body.Close()
action := utils.ResolveAction(bridgeData.SessionURL, string(formHTML))
formData := utils.ExtractFormFields(string(formHTML))
pResp, _ := mainClient.PostForm(action, formData)
pHtml, _ := io.ReadAll(pResp.Body)
pResp.Body.Close()
redirectRegex := regexp.MustCompile(`window\.location\.replace\('([^']+)'\)`)
finalMatch := redirectRegex.FindStringSubmatch(string(pHtml))
var finalHTML string
var finalURL string
if len(finalMatch) > 1 {
finalURL = finalMatch[1]
} else {
validData := utils.ExtractFormFields(string(pHtml))
validData.Set("__EVENTTARGET", "checkedLtiPostMessage")
validData.Set("__EVENTARGUMENT", "")
validData.Set("checkedLtiPostMessage", "true")
validData.Set("ltiPostMessage", "")
finalResp, _ := mainClient.PostForm(action, validData)
finalHTMLBytes, _ := io.ReadAll(finalResp.Body)
finalHTML = string(finalHTMLBytes)
finalResp.Body.Close()
finalMatch = redirectRegex.FindStringSubmatch(finalHTML)
if len(finalMatch) > 1 {
finalURL = finalMatch[1]
}
}
if finalURL != "" {
cleanURL := strings.ReplaceAll(finalURL, `\x`, "%")
decodedURL, err := url.QueryUnescape(cleanURL)
if err != nil {
decodedURL = cleanURL
}
fmt.Printf("[+] Panopto URL Found: %s\n", decodedURL)
cookieFile := filepath.Join(root, ".cookies_main.txt")
cData := "# Netscape HTTP Cookie File\n"
panoptoURL, _ := url.Parse("https://vub.cloud.panopto.eu")
for _, cookie := range mainClient.Jar.Cookies(panoptoURL) {
cData += fmt.Sprintf(".vub.cloud.panopto.eu\tTRUE\t/\tTRUE\t0\t%s\t%s\n", cookie.Name, cookie.Value)
}
os.WriteFile(cookieFile, []byte(cData), 0o644)
recordingsDir := filepath.Join(root, "Recordings")
os.MkdirAll(recordingsDir, 0o755)
fmt.Println("[*] Starting yt-dlp download for main recordings...")
ytCmd := getYoutubeDLCommand()
cmd := exec.Command(ytCmd,
"--cookies", cookieFile,
"--referer", config.BaseURL+"/",
"-P", recordingsDir,
"-o", "%(playlist_title)s/%(title)s.%(ext)s",
decodedURL,
)
cmd.Stdout = os.Stdout
cmd.Stderr = os.Stderr
cmd.Run()
os.Remove(cookieFile)
} else {
fmt.Println("[!] No main recordings available or handshake failed")
}
}