R/crypt.R

In rpruim/webwork: Utilities for Working with WeBWorK

crypt1 <- function(plaintext, salt = NULL ) {

  if (is.null(salt)) {
    characters <- c(LETTERS, letters, format(0:9), ".", "/")
    salt <- paste0(characters[sample(seq_along(characters), size = 2, replace = TRUE)], collapse = "")
  }

  # From WeBWorK:
  #
  # To crypt a password, use the following perl one-liner:
  #
  #   perl -e 'while(1){print"plaintext? ";<>;chomp;print"crypted: ".crypt($_,join"",(".","/",0..9,"A".."Z","a".."z")[rand 64,rand 64])."\n"}'
  #
  # You can also create a classlist file with plaintext passwords, and then use the following perl one-liner to crypt them:
  #
  #   perl -pe '@a=split",";$a[9]and$a[9]=crypt($a[9],join"",(".","/",0..9,"A".."Z","a".."z")[rand 64,rand 64]);$_=join",",@a' < plaintext.lst > crypted.lst
  #

  command <- paste0(
    "perl -e 'print crypt(\"",  plaintext,  "\", \"",  salt,  "\")'"
  )

  system(command, intern = TRUE)
}

#' Create crypted passwords
#'
#' WeBWorK passwords must be crypted with a 1-way hash. `crypt()` is a wrapper around the suggested perl code
#' for performing the crypting.
#'
#' @param plaintext Plain text to be hashed
#' @param salt A two-character string used as "salt" for the hash.  If `NULL`, salt is randomly generated.
#' @rdname crypt
#' @examples
#' crypt("plaintext")
#' crypt("plaintext", salt = "N7")
#' crypt("plaintext", salt = "Xa")
#' crypt(LETTERS)
#' @export

crypt <- Vectorize(crypt1)