Wrapper functions for encryption. These functions wrap expressions that produce or consume a file and arrange to encrypt (for producing functions) or decrypt (for consuming functions). The forms with a trailing underscore (encrypt_, decrypt_) do not use any non-standard evaluation and may be more useful for programming.

encrypt(expr, key, file_arg = NULL, envir = parent.frame())

decrypt(expr, key, file_arg = NULL, envir = parent.frame())

encrypt_(expr, key, file_arg = NULL, envir = parent.frame())

decrypt_(expr, key, file_arg = NULL, envir = parent.frame())

Arguments

expr

A single expression representing a function call that would be called for the side effect of creating or reading a file.

key

A cyphr_key object describing the encryption approach to use.

file_arg

Optional hint indicating which argument to expr is the filename. This is done automatically for some built-in functions.

envir

Environment in which expr is to be evaluated.

Details

These functions will not work for all functions. For example pdf/dev.off will create a file but we can't wrap those up (yet!). Functions that modify a file (e.g., appending) also will not work and may cause data loss.

Examples

# To do anything we first need a key: key <- cyphr::key_sodium(sodium::keygen()) # Encrypted write.csv - note how any number of arguments to # write.csv will be passed along path <- tempfile(fileext = ".csv") cyphr::encrypt(write.csv(iris, path, row.names = FALSE), key) # The new file now exists file.exists(path)
#> [1] TRUE
# ...but it cannot be read with read.csv! try(read.csv(path, stringsAsFactors = FALSE))
#> Warning: line 1 appears to contain embedded nulls
#> Warning: line 3 appears to contain embedded nulls
# Wrap the read.csv call with cyphr::decrypt() dat <- cyphr::decrypt(read.csv(path, stringsAsFactors = FALSE), key) head(dat)
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species #> 1 5.1 3.5 1.4 0.2 setosa #> 2 4.9 3.0 1.4 0.2 setosa #> 3 4.7 3.2 1.3 0.2 setosa #> 4 4.6 3.1 1.5 0.2 setosa #> 5 5.0 3.6 1.4 0.2 setosa #> 6 5.4 3.9 1.7 0.4 setosa
#> [1] TRUE
# If you have a function that is not supported you can specify the # filename argument directly. For example, with "write.dcf" the # filename argument is called "file"; we can pass that along path <- tempfile() cyphr::encrypt(write.dcf(list(a = 1), path), key, file_arg = "file") # Similarly for decryption: cyphr::decrypt(read.dcf(path), key, file_arg = "file")
#> a #> [1,] "1"