R GDAX-API Delete Request - r

Question

I am having trouble with DELETE requests in R. I have been successful in making GET and POST requests using the below code. Any help / pointers will be appreciated.
It will require an api.key, secret & passphrase from GDAX to work.
Here is my function:
library(RCurl)
library(jsonlite)
library(httr)
library(digest)
cancel_order <- function(api.key,
secret,
passphrase) {
api.url <- "https://api.gdax.com"
#get url extension----
req.url <- "/orders/"
#define method----
method = "DELETE"
url <- paste0(api.url, req.url)
timestamp <-
format(as.numeric(Sys.time()), digits = 13) # create nonce
key <- base64Decode(secret, mode = "raw") # encode api secret
#create final end point----
what <- paste0(timestamp, method, req.url)
#create encoded signature----
sign <-
base64Encode(hmac(key, what, algo = "sha256", raw = TRUE)) # hash
#define headers----
httpheader <- list(
'CB-ACCESS-KEY' = api.key,
'CB-ACCESS-SIGN' = sign,
'CB-ACCESS-TIMESTAMP' = timestamp,
'CB-ACCESS-PASSPHRASE' = passphrase,
'Content-Type' = 'application/json'
)
##------------------------------------------------
response <- getURL(
url = url,
curl = getCurlHandle(useragent = "R"),
httpheader = httpheader
)
print(rawToChar(response)) #rawToChar only on macOS and not on Win
}
The error I get is "{\"message\":\"invalid signature\"}" even though the same command will code and signature will work with GET & POST.
Ref: GDAX API DOCs

Answer 1

just a guess as I am not familiar with the API, but perhaps you are missing the 'order-id' ...
look at: https://docs.gdax.com/?javascript#cancel-an-order

Answer 2

Ok. I took #mrflick's advise and pointed my connection to requestbin based on his feedback on a different but related question.
After careful inspection, I realized that the my request for some reason was treated as a POST request and not a DELETE request. So I decided to replace the getURL function with another higher level function from RCurl for it to work.
response <- httpDELETE(
url = url,
curl = getCurlHandle(useragent = "R"),
httpheader = httpheader
)
Everything else remains the same. Apparently there never was an issue with the signature.
I have added this function now to my unofficial wrapper rgdax
EDIT::
The unofficial wrapper is now official and on CRAN.