ipv4_regex <- "^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$" S_GET <- safely(httr::GET) #' Perform DNS over HTTPS queries using Google #' #' Traditional DNS queries and responses are sent over UDP or TCP without #' encryption. This is vulnerable to eavesdropping and spoofing (including #' DNS-based Internet filtering). Responses from recursive resolvers to clients #' are the most vulnerable to undesired or malicious changes, while #' communications between recursive resolvers and authoritative nameservers #' often incorporate additional protection.\cr #' \cr #' To address this problem, Google Public DNS offers DNS resolution over an #' encrypted HTTPS connection. DNS-over-HTTPS greatly enhances privacy and #' security between a client and a recursive resolver, and complements DNSSEC #' to provide end-to-end authenticated DNS lookups. #' #' To perform vectorized queries with only answers (and no metadata) use #' \code{bulk_query()}). #' #' @param name item to lookup. Valid characters are numbers, letters, hyphen, and dot. Length #' must be between 1 and 255. Names with escaped or non-ASCII characters #' are not supported. Internationalized domain names must use the #' punycode format (e.g. "\code{xn--qxam}").\cr #' \cr If an IPv4 string is input, it will be transformed into #' a proper format for reverse lookups. #' @param type RR type can be represented as a number in [1, 65535] or canonical #' string (A, aaaa, etc). More information on RR types can be #' found \href{http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#dns-parameters-4}{here}. #' You can use \code{255} for an \code{ANY} query. #' @param cd (Checking Disabled) flag. Use `TRUE` to disable DNSSEC validation; #' Default: `FALSE`. #' @param do (DNSSEC OK) flag. Use `TRUE` include DNSSEC records (RRSIG, NSEC, NSEC3); #' Default: `FALSE`. #' @param random_padding clients concerned about possible side-channel privacy #' attacks using the packet sizes of HTTPS GET requests can use this to #' make all requests exactly the same size by padding requests with random data. #' To prevent misinterpretation of the URL, restrict the padding characters to #' the unreserved URL characters: upper- and lower-case letters, digits, #' hyphen, period, underscore and tilde. #' @param edns_client_subnet The edns0-client-subnet option. Format is an IP #' address with a subnet mask. Examples: \code{1.2.3.4/24}, #' \code{2001:700:300::/48}.\cr #' If you are using DNS-over-HTTPS because of privacy concerns, and do #' not want any part of your IP address to be sent to authoritative #' nameservers for geographic location accuracy, use #' \code{edns_client_subnet=0.0.0.0/0}. Google Public DNS normally sends #' approximate network information (usually replacing the last part of #' your IPv4 address with zeroes). \code{0.0.0.0/0} is the default. #' @return a \code{list} with the query result or \code{NULL} if an error occurred #' @references #' @export #' @examples #' query("rud.is") #' dig("example.com", "255") # ANY query #' query("microsoft.com", "MX") #' dig("google-public-dns-a.google.com", "TXT") #' query("apple.com") #' dig("17.142.160.59", "PTR") query <- function(name, type = "1", cd = FALSE, do = FALSE, edns_client_subnet = "0.0.0.0/0", random_padding = NULL) { name <- name[1] # helper to turn IPv4 addresses in to in-addr.arpa. if (grepl(ipv4_regex, name)) { name <- paste0(c(rev(unlist(stringi::stri_split_fixed(name, ".", 4))), "in-addr.arpa."), sep="", collapse=".") } res <- S_GET( url = "https://dns.google/resolve", query = list( name = name, type = type, cd = if (cd) 1 else 0, do = if (do) 1 else 0, ct = "application/x-javascript", edns_client_subnet = edns_client_subnet, random_padding = random_padding ) ) if (!is.null(res$result)) { stop_for_status(res$result) txt <- httr::content(res$result, as="text") txt <- stringi::stri_enc_toascii(txt) txt <- stringi::stri_replace_all_regex(txt, "[[:cntrl:][:blank:]\\n ]+", " ") out <- jsonlite::fromJSON(txt) class(out) <- c("gdns_response", "list") out } else { NULL } } #' @rdname query #' @export dig <- query