calDAV "PROPFIND" call "401 Unauthorized" response from calendar.yahoo.com server - php

Question

I am trying to send yahoo calendars(caldav) a request to get "current-user-principal" But In response I am getting "401 Unauthorized" error. Before this request I am making another request to get "OPTIONS" which is giving "200 OK" response.
Request call is
PROPFIND / HTTP/1.1
Authorization: Basic XXXXXXXXXXXXXXXX=
Host: calendar.yahoo.com:443
Depth: 0
Prefer: return-minimal
Content-type: application/xml; charset=utf-8
Content-Length: 85
User-Agent: DAViCalClient
Connection: close
Request Response is:
string(613) "HTTP/1.1 401 Unauthorized
WSHost: tardis012.cal.bf1.yahoo.com
Set-Cookie: rememberMe=deleteMe; Path=/; Max-Age=0; Expires=Thu, 18-Feb-2021 03:44:03 GMT
WWW-Authenticate: Basic realm="YahooCalendar"
WWW-Authenticate: OAuth realm="YahooCalendar"
Content-Length: 0
Date: Fri, 19 Feb 2021 03:44:03 GMT
Age: 1
Server: ATS
Referrer-Policy: no-referrer-when-downgrade
Connection: close
Strict-Transport-Security: max-age=15552000
Expect-CT: max-age=31536000, report-uri="http://csp.yahoo.com/beacon/csp?src=yahoocom-expect-ct-report-only"
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
I am using a client library which has a function to make server request
function DoRequest( $relative_url = "" ) {
if(!defined("_FSOCK_TIMEOUT")){ define("_FSOCK_TIMEOUT", 10); }
$headers = array();
$headers[] = $this->requestMethod." ". $this->base_url . $relative_url . " HTTP/1.1";
$headers[] = "Authorization: Basic ".base64_encode($this->user .":". $this->pass );
$headers[] = "Host: ".$this->server .":".$this->port;
foreach( $this->headers as $ii => $head ) {
$headers[] = $head;
}
$headers[] = "Content-Length: " . strlen($this->body);
$headers[] = "User-Agent: " . $this->user_agent;
$headers[] = 'Connection: close';
$this->httpRequest = join("\r\n",$headers);
$this->xmlRequest = $this->body;
$fip = fsockopen( $this->protocol . '://' . $this->server, $this->port, $errno, $errstr, _FSOCK_TIMEOUT); //error handling?
if ( !(get_resource_type($fip) == 'stream') ) return false;
if ( !fwrite($fip, $this->httpRequest."\r\n\r\n".$this->body) ) { fclose($fip); return false; }
$rsp = "";
while( !feof($fip) ) { $rsp .= fgets($fip,8192); }
fclose($fip);
$this->headers = array(); // reset the headers array for our next request
$this->ParseResponse($rsp);
return $rsp;
}
Here is class init.
$cal = new CalDAVClient("https://calendar.yahoo.com/", "piyush138", "XXXXXXXXXXX", "calendar" );
Link to library
The following request gives "200 ok" response which runs before above request:
Request to server
OPTIONS / HTTP/1.1
Authorization: Basic cGl5dXNoMTM4OkQxZzF0YWxoZWw=
Host: calendar.yahoo.com:443
Content-Length: 0
User-Agent: DAViCalClient
Connection: close
Response from server
string(668) "HTTP/1.1 200 OK
WSHost: tardis030.cal.bf1.yahoo.com
Set-Cookie: rememberMe=deleteMe; Path=/; Max-Age=0; Expires=Thu, 18-Feb-2021 03:44:01 GMT
DAV: 1, 3, calendar-access
MS-Author-Via: DAV
Allow: HEAD, MKCOL, POST, PROPFIND, ACL, COPY, REPORT, OPTIONS, PUT, DELETE, MKCALENDAR, MOVE, GET, PROPPATCH
Content-Length: 0
Date: Fri, 19 Feb 2021 03:44:02 GMT
Age: 3
Server: ATS
Referrer-Policy: no-referrer-when-downgrade
Connection: close
Strict-Transport-Security: max-age=15552000
Expect-CT: max-age=31536000, report-uri="http://csp.yahoo.com/beacon/csp?src=yahoocom-expect-ct-report-only"
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
I also tried simplifying my password but that didn't work either

Answer 1

I have found the Solution.
I was using the conventional password in server call but in actual I had to use "APP Password" which you can create from
your yahoo account Under "Account security" tab.