> library(RCurl)
> sessionInfo()
R version 4.0.2 (2020-06-22)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 19041)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252 
[2] LC_CTYPE=English_United States.1252   
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] RCurl_1.98-1.2

loaded via a namespace (and not attached):
[1] compiler_4.0.2 tools_4.0.2    tinytex_0.24   xfun_0.15     
[5] bitops_1.0-6  
> curlVersion()
$age
[1] 3

$version
[1] "7.40.0"

$vesion_num
[1] 468992

$host
[1] "x86_64-pc-win32"

$features
      ssl      libz      ntlm asynchdns    spnego largefile       idn 
        4         8        16       128       256       512      1024 
     sspi 
     2048 

$ssl_version
[1] "OpenSSL/1.0.0o"

$ssl_version_num
[1] 0

$libz_version
[1] "1.2.8"

$protocols
 [1] "dict"   "file"   "ftp"    "ftps"   "gopher" "http"   "https" 
 [8] "imap"   "imaps"  "ldap"   "pop3"   "pop3s"  "rtmp"   "rtsp"  
[15] "scp"    "sftp"   "smtp"   "smtps"  "telnet" "tftp"  

$ares
[1] ""

$ares_num
[1] 0

$libidn
[1] ""

> libcurlVersion()
[1] "7.64.1"
attr(,"ssl_version")
[1] "OpenSSL/1.1.1d (Schannel)"
attr(,"libssh_version")
[1] "libssh2/1.8.2"
attr(,"protocols")
 [1] "dict"   "file"   "ftp"    "ftps"   "gopher" "http"   "https" 
 [8] "imap"   "imaps"  "ldap"   "ldaps"  "pop3"   "pop3s"  "rtsp"  
[15] "scp"    "sftp"   "smtp"   "smtps"  "telnet" "tftp"