CODEWITHSUNDEEP
rsftprcurl
Stu
Stu

Reputation: 1653

Problems connecting to SFTP with R and RCurl

I am attempting to connect to an SFTP site to pull data. It used to work, but for some reason, it stopped working a couple of weeks ago. The owners of the SFTP say nothing has changed on their end, and I can pull data easily without error using WinSCP.

protocol <- "sftp"
server <- "sftp.xxxx.net"
userpwd <- "user:password"
file <- "/public/bpus_dailytx.csv"
url <- paste0(protocol, "://", server, file)
data <- getURL(url = url, userpwd=userpwd, verbose = TRUE)

When I run this, I now get the following info: 

*   Trying xxx.xx.xx.xxx...
* Connected to sftp.xxxx.net (xxx.xx.xx.xxx) port 22 (#0)
* SSH MD5 fingerprint: 34rh3ie93hhr39hhdik3
* SSH authentication methods available: publickey,keyboard-interactive
* Using SSH public key file '(nil)'
* Using SSH private key file ''
* SSH public key authentication failed: Unable to extract public key from private key file: Unable to open private key file
* No identity would match
* Authentication failure
* Closing connection 0
Error in function (type, msg, asError = TRUE)  : Authentication failure

It connects OK but then the authentication fails. Any ideas what could be going on here? Again, this code used to work but something has changed. What are some other ways I can attempt to pull the data other than this?

Edit: WinSCP screenshots: enter image description here enter image description here

Upvotes: 3

Views: 3488

Answers (1)

the-mad-statter
the-mad-statter

Reputation: 8936

It is difficult to say why your code stopped working because we do not have enough information about configurations (both on your machine and on the server) when it was working.

Because your keyfile was not in the proper format for RCurl, my leading hypothesis is that although the server folks said nothing changed on their end, I think they removed the password authentication option. That is because your code attempts password authentication only. If password authentication were still available, the one line in your output would look something like this:

SSH authentication methods available: publickey,password,keyboard-interactive

It is, as you noted, now:

SSH authentication methods available: publickey,keyboard-interactive

Therefore, the solution here was to convert your keyfile from PuTTY to OpenSSH format using PuTTYgen and then use the following RCurl code pointing to your new keyfile:

protocol <- "sftp"
server <- "sftp.xxxx.net"
file <- "/public/bpus_dailytx.csv"
url <- paste0(protocol, "://", server, file)

keypasswd <- "your_keypasswd"
ssh.private.keyfile = "your_path_to_keyfile"
username <- "your_username"

data <- getURL(url = url, keypasswd = keypasswd, ssh.private.keyfile = ssh.private.keyfile, username = username, verbose = TRUE)

And I will add a special thanks to @Tensibai for the assistance. It would have taken me way longer to arrive at this solution without their insight with the keyfile format.

Upvotes: 4

Related Questions