RCurl getURL SSL error

Question

Related questions:

RCurl errors when fetching ssl endpoint

R: Specify SSL version in Rcurl getURL statement

I am looking at the following:

url = https://www.veilingbiljet.nl/resultaten-ajax.asp?order=datum&direction=D&page=1&field=0&regio=39

Then,

getURL(url)

gives the following error:

error:1411809D:SSL routines:SSL_CHECK_SERVERHELLO_TLSEXT:tls invalid ecpointformat list

Adding the followinf curl option, suggested in one of the related questions,

getURL(url, ssl.verifypeer = TRUE,sslversion=3L)

returns

Unknown SSL protocol error in connection to www.veilingbiljet.nl:443

Any help would be greatly appreciated.

Answer 1

The RCurl package is unmaintained and defunct. Use the curl package or httr instead:

library(curl)
con <- curl("https://www.veilingbiljet.nl/resultaten-ajax.asp?order=datum&direction=D&page=1&field=0&regio=39")
readLines(con)

Or:

library(httr)
req <- GET("https://www.veilingbiljet.nl/resultaten-ajax.asp?order=datum&direction=D&page=1&field=0&regio=39")
stop_for_status(req)
content(req)

Answer 2

error:1411809D:SSL routines:SSL_CHECK_SERVERHELLO_TLSEXT:tls invalid ecpointformat list

This is a known bug in old OpenSSL versions and was fixed about 4 years ago. Thus upgrading your local OpenSSL should help.

If this is not possible you might disable the use of the affected ciphers by setting the ssl.cipher.list option of RCurl to HIGH:!ECDH.

Unknown SSL protocol error in connection to www.veilingbiljet.nl:443

The server does not support SSL 3.0 so trying to enforce this version will fail.