CODEWITHSUNDEEP
roauth
assumednormal
assumednormal

Reputation: 366

query yelp from r using http request - invalid signature

I'm trying to query Yelp from within R by HTTP request. I'm having trouble getting the oauth_signature parameter to match what Yelp is expecting.

Here's my code so far.

YWSID <- "..."
CONSUMER_KEY <- "..."
CONSUMER_SECRET <- "..."
TOKEN <- "..."
TOKEN_SECRET <- "..."

yelp_bus <- function(rest, ywsid, cons_key, cons_sec, tok, tok_sec) {
    require(package = "digest")
    require(package = "rjson")
    require(package = "RCurl")
    require(package = "stringr")
    rest1 <- gsub(pattern = " ", replacement = "%2520", x = rest)
    rest2 <- gsub(pattern = " ", replacement = "+", x = rest)
    nonce <- paste(sample(x = c(0:9, letters, LETTERS, "_"), size = 32, replace = TRUE), collapse = "")
    tm <- format(x = Sys.time(), "%s")
    api_url <- paste("GET\u0026http%3A%2F%2Fapi.yelp.com%2Fv2%2Fsearch\u0026",
                     "limit%3D1%26location%3DChicago%2520IL%26",
                     "oauth_consumer_key%3D", cons_key, "%26",
                     "oauth_nonce%3D", nonce, "%26",
                     "oauth_signature_method%3DHMAC-SHA1%26",
                     "oauth_timestamp%3D", tm, "%26",
                     "oauth_token%3D", tok, "%26",
                     "term%3D", rest1,
                     sep = "")
    signature <- hmac(key = tok_sec, object = api_url, algo = "sha1")
    api_url <- paste("http://api.yelp.com/v2/search?",
                     "limit=1&location=Chicago+IL&",
                     "oauth_consumer_key=", cons_key, "&",
                     "oauth_nonce=", nonce, "&",
                     "oauth_signature=", signature, "&",
                     "oauth_signature_method=HMAC-SHA1&",
                     "oauth_timestamp=", tm, "&",
                     "oauth_token=", tok, "&",
                     "term=", rest2,
                     sep = "")
    return(api_url)
}

yelp_bus(rest = "chez moi",
         ywsid = YWSID,
         cons_key = CONSUMER_KEY,
         cons_sec = CONSUMER_SECRET,
         tok = TOKEN,
         tok_sec = TOKEN_SECRET)

I get an this error back every time.

{"error": {"text": "Signature was invalid", "id": "INVALID_SIGNATURE", "description": "Invalid signature. Expected signature base string: ..."}}

Upvotes: 3

Views: 764

Answers (1)

ianmcook
ianmcook

Reputation: 743

Create the signature as follows:

signature <- as.character(curlPercentEncode(base64(hmac(key=paste(cons_sec, tok_sec, sep="&"), object=api_url, algo="sha1", serialize=FALSE, raw=TRUE))))

Upvotes: 3

Related Questions