Webread certificate problems - roll your own java works, webread doesn't. Why?

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Could someone explain to me why this would fail with an obscure message
webread('http://website/', 'Authorization', ['Basic ' matlab.net.base64encode(['me:secr3t'])])
The reason is "error:14090086:SSL routines:ssl3_get_server_certificate:certificate
verify failed". Check your certificate file (C:\Program Files\MATLAB\R2018a\sys\certificates\ca\rootcerts.pem) for expired, missing or invalid certificates.
Whereas this (lightly modified and shamelessly stolen from stack overflow) appears to have no problems. Is webread doing something kooky that causes it to barf on the proxy server, where java is not? Why does matlab have certificate problems?
urlread_auth('https://website/','me','secr3t' )
function [s,info] = urlread_auth(url, user, password)
%URLREAD_AUTH Like URLREAD, with basic authentication
% [s,info] = urlread_auth(url, user, password)
% Returns bytes. Convert to char if you're retrieving text.
% Examples:
% sampleUrl = 'http://browserspy.dk/password-ok.php';
% [s,info] = urlread_auth(sampleUrl, 'test', 'test');
% txt = char(s)
% Matlab's urlread() doesn't do HTTP Request params, so work directly with Java
jUrl = java.net.URL(url);
conn = jUrl.openConnection();
conn.setRequestProperty('Authorization', ['Basic ' matlab.net.base64encode([user ':' password])]);
info.status = conn.getResponseCode();
info.errMsg = char(readstream(conn.getErrorStream()));
s = readstream(conn.getInputStream());
function out = readstream(inStream)
%READSTREAM Read all bytes from stream to uint8
import com.mathworks.mlwidgets.io.InterruptibleStreamCopier;
byteStream = java.io.ByteArrayOutputStream();
isc = InterruptibleStreamCopier.getInterruptibleStreamCopier();
isc.copyStream(inStream, byteStream);
out = typecast(byteStream.toByteArray', 'uint8'); %'
catch err
out = []; %HACK: quash

Accepted Answer

Simon Parten
Simon Parten on 26 Jan 2018
Edited: Walter Roberson on 2 Mar 2019
""" I solved it by setting the options=weboptions; options.CertificateFilename=(''); webread(URL,options); """
I also then needed to set the RequestMethod as POST, and crucially, use the 'webwrite' function, as opposed to the 'webread' function. Suddenly, things burst into life ...

More Answers (1)

Darshan Ramakant Bhat
Darshan Ramakant Bhat on 17 Jan 2018
There is a detailed answer available for the similar issue in the below answer link:
I hope this will help you.
  1 Comment
Adam Schroeder
Adam Schroeder on 14 Mar 2022
It looks like this link is no longer active. I was able to work through this successfully using Simon's accepted answer and Jörgen's comment.

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