r - 使用 http 请求从 r 查询 yelp - 签名无效

Question

我正在尝试通过 HTTP 请求从 R 中查询 Yelp。我在获取 oauth_signature 参数以匹配 Yelp 的预期时遇到问题。

到目前为止，这是我的代码。

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)

我每次都会收到此错误。

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

Answer 1

创建签名如下:

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