cURL error – unable to download image to server

littlepear
(@littlepear)

2 years, 4 months ago

“cURL error – unable to download image to server, please contact your server administrator to enable cURL”

Local WAMPServer on Windows 10 machine.
I have tried each of the three solutions at https://connekthq.com/plugins/instant-images/
Permissions, Max Upload Size, and REST API Blocked, to no avail.

Viewing 9 replies - 1 through 9 (of 9 total)

Plugin Author dcooney
(@dcooney)

2 years, 4 months ago

HI @littlepear,
As the error message suggests, do you have cURL enabled on the server?

littlepear
(@littlepear)

2 years, 4 months ago

Yes.

cURL support enabled
cURL Information 7.59.0
Age 4
Features
AsynchDNS Yes
CharConv No
Debug No
GSS-Negotiate No
IDN Yes
IPv6 Yes
krb4 No
Largefile Yes
libz Yes
NTLM Yes
NTLMWB No
SPNEGO Yes
SSL Yes
SSPI Yes
TLS-SRP No
HTTP2 Yes
GSSAPI No
KERBEROS5 Yes
UNIX_SOCKETS No
PSL No
Protocols dict, file, ftp, ftps, gopher, http, https, imap, imaps, ldap, pop3, pop3s, rtsp, scp, sftp, smb, smbs, smtp, smtps, telnet, tftp
Host x86_64-pc-win32
SSL Version OpenSSL/1.1.0g
ZLib Version 1.2.11
libSSH Version libssh2/1.8.0

Plugin Author dcooney
(@dcooney)

2 years, 4 months ago

Ok thanks, strange because the cURL error only appears if the cURL action fails.
I’ll try to set up a WAMPServer on a windows machine next week to test.
shelkie
(@shelkie)

2 years, 4 months ago
I’ve run into this problem as well while using Flywheel for hosting, but tracked down the issue.

First, in upload.php, I added some error reporting for the cURL operation so I could see what was happening. Near upload.php:75
```
$picture = curl_exec($ch);
if (curl_error($ch)) {
  $response = array(
    'error' => true,
    'msg' => __('cURL error - ' . curl_error($ch), 'instant-images'),
    'path' => '',
    'filename' => ''
  );
  curl_close($ch);
  wp_send_json($response);
  return;
}
```
which gave me: “SSL certificate problem: unable to get local issuer certificate” Which I fixed by adding these lines to your curl options at line 73
```
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_BINARYTRANSFER,1);
```
Hope this helps others with the same problem!
- This reply was modified 2 years, 4 months ago by shelkie.
- This reply was modified 2 years, 4 months ago by shelkie.
shelkie
(@shelkie)

2 years, 4 months ago
Sorry, goofed in my copying and pasting my previous comment. The curl options to add are:
```
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
```
- This reply was modified 2 years, 4 months ago by shelkie.
Plugin Author dcooney
(@dcooney)

2 years, 4 months ago
Hi @shelkie,
In 3.2 I added some cURL error handling but yours seems like more a better solution as it relays the cURL error.
```
...
$picture = curl_exec($ch);
curl_close($ch);
// cURL error
if ($picture === FALSE) {   
   $response = array(
		'error' => true,
		'msg' => __('cURL error - Unable to download image to server, please contact your server administrator to enable cURL.', 'instant-images'),
		'path' => '',
		'filename' => ''
	);   
} 
```
I’ve never run into the cURL issue before, but would you recommend adding:
```
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 0);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
```
to the next release?
shelkie
(@shelkie)

2 years, 4 months ago
The “SSL certificate problem: unable to get local issuer certificate” error is caused by the CA bundle being out of date on the server. Difficult/impossible to update this sort of thing in a shared hosting environment though.

While turning off VERIFYHOST and VERIFYPEER is not ideal as it diminishes the security of your cURL request, this shouldn’t be an issue as the data being transferred in this case is not sensitive.
- This reply was modified 2 years, 4 months ago by shelkie.
- This reply was modified 2 years, 4 months ago by shelkie.
- This reply was modified 2 years, 4 months ago by shelkie.
Plugin Author dcooney
(@dcooney)

2 years, 4 months ago

Probably shouldn’t advertise that if it’s so.

Basically, the user needs permissions to access the REST API.

jsaturno
(@jsaturno)

2 years, 4 months ago

I have the same error and it is still there even after changing upload.php as you suggested 🙁