[R] Windows build 4.2.0 of R: libcurl not picking up self signed certificate from windows os, worked for 4.1.3

[ralpholsson]

Hello,

Using the official windows build of R 4.2.0 from the CRAN website I can 
no longer download files from an internal website with a self signed 
certificate. This worked under build 4.1.3.

I apologise that the url in the following example is not publicly 
available and that the example is therefore not directly reproducible, 
this is a necessary part of the problem due to dealing with self signed 
certificates.

In 4.2.0:

> libcurlVersion()
[1] "7.81.0"
attr(,"ssl_version")
[1] "(OpenSSL/1.1.1m) Schannel"
attr(,"libssh_version")
[1] "libssh2/1.10.0"
attr(,"protocols")
  [1] "dict"    "file"    "ftp"     "ftps"    "gopher"  "gophers" "http" 
"https"   "imap"    "imaps"   "ldap"    "ldaps"   "mqtt"    "pop3" 
"pop3s"   "rtsp"    "scp"     "sftp"
> 
> download.file("https://my.site.com/index.html","./index.html",method="libcurl")
trying URL 'https://my.site.com/index.html'
Error in download.file("https://my.site.com/index.html",  :
   cannot open URL 'https://my.site.com/index.html'
In addition: Warning message:
In download.file("https://my.site.com/index.html",  :
   URL 'https://my.site.com/index.html': status was 'SSL peer 
certificate or SSH remote key was not OK'

In 4.1.3:

> libcurlVersion()
[1] "7.64.1"
attr(,"ssl_version")
[1] "(OpenSSL/1.1.1m) Schannel"
attr(,"libssh_version")
[1] "libssh2/1.8.2"
attr(,"protocols")
  [1] "dict"   "file"   "ftp"    "ftps"   "gopher" "http"   "https" 
"imap"   "imaps"  "ldap"   "ldaps"  "pop3"   "pop3s"  "rtsp"   "scp" 
"sftp"   "smtp"   "smtps"  "telnet"
[20] "tftp"
> 
> download.file("https://my.site.com/index.html","./index.html",method="libcurl")
trying URL 'https://my.site.com/index.html'
Content length 11082 bytes (10 KB)
downloaded 10 KB

My reading suggests that since libcurlVersion() reports "Schannel" in 
both cases it should be picking up the same certificates from the OS.

Please advise, many thanks,

Ralph