safer

A consistent interface to encrypt/decrypt strings, objects, files and connections in R. Both symmetric and asymmetric encryption methods are supported. Thanks to excellent packages sodium and base64enc.

Design

There are four functions and their (inverses).

• encryt_string (decrypt_string)
• encryt_object (decrypt_object)
• encryt_file (decrypt_file)
• save_object (retrieve_object)

The following table summarizes their functionality:

Function	Input	Output	Has side-effect
encryt\_string	a string	string/raw	No
encryt\_object	a R object	raw/string	No
encrypt\_file	a file on disk	TRUE	Yes (Output to disk)
save\_object	a R object	TRUE	Yes (Output to disk)

Examples

library("safer")

String

# symmetric case:
temp <- encrypt_string("hello, how are you", key = "secret")
all(
  is.character(temp)
  , decrypt_string(temp, "secret") == "hello, how are you"
  , class(try(decrypt_string(temp, "nopass"), silent = TRUE)) == "try-error"
  )

## [1] TRUE

res <- encrypt_string("tatvamasi", ascii = FALSE)
isTRUE(identical(decrypt_string(res), "tatvamasi"))

## [1] TRUE

# asymmetric case:
alice <- keypair()
bob   <- keypair()
temp  <- encrypt_string("hello asymmetric", alice$private_key, bob$public_key)
temp2 <- decrypt_string(temp, bob$private_key, alice$public_key)
identical("hello asymmetric", temp2)

## [1] TRUE

Henceforth, we shall default password for symmetric case: pass.

Object

# symmetric case:
temp <- encrypt_object(1:3)
all(
  is.raw(temp)
  , decrypt_object(temp) == 1:3)

## [1] TRUE

temp <- encrypt_object(iris, ascii = TRUE)
all(
  is.character(temp)
  , decrypt_object(temp) == iris
  , identical(decrypt_object(temp), iris))

## [1] TRUE

rm(temp)

# asymmetric case:
alice <- keypair()
bob   <- keypair()
temp  <- encrypt_object(1:10, alice$private_key, bob$public_key)
temp2 <- decrypt_object(temp, bob$private_key, alice$public_key)
identical(1:10, temp2)

## [1] TRUE

File

# symmetric case:
write.table(iris, "iris.csv")
all(
  encrypt_file("iris.csv", outfile = "iris_encrypted.bin")
  , file.exists("iris_encrypted.bin")
  , decrypt_file("iris_encrypted.bin", outfile = "iris_2.csv")
  , file.exists("iris_2.csv")
  , tools::md5sum("iris_2.csv") == tools::md5sum("iris.csv")
  , unlink("iris.csv") == 0
  , unlink("iris_2.csv") == 0
  , unlink("iris_encrypted.bin") == 0
)

## [1] TRUE

write.table(iris, "iris.csv")
all(
  encrypt_file("iris.csv", outfile = "iris_encrypted.txt", ascii = TRUE)
  , file.exists("iris_encrypted.txt")
  , decrypt_file("iris_encrypted.txt", outfile = "iris_2.csv", ascii = TRUE)
  , file.exists("iris_2.csv")
  , tools::md5sum("iris_2.csv") == tools::md5sum("iris.csv")
  , unlink("iris.csv") == 0
  , unlink("iris_2.csv") == 0
  , unlink("iris_encrypted.txt") == 0
)

## [1] TRUE

# asymmetric case:
alice <- keypair()
bob   <- keypair()
write.table(iris, "iris.csv")
all(
  encrypt_file("iris.csv", alice$private_key, bob$public_key, outfile = "iris_encrypted.bin")
  , file.exists("iris_encrypted.bin")
  , decrypt_file("iris_encrypted.bin", bob$private_key, alice$public_key, outfile = "iris_2.csv")
  , file.exists("iris_2.csv")
  , tools::md5sum("iris_2.csv") == tools::md5sum("iris.csv")
  , unlink("iris.csv") == 0
  , unlink("iris_2.csv") == 0
  , unlink("iris_encrypted.bin") == 0
)

## [1] TRUE

Save

# symmetric case:
all(
  save_object(iris, conn = "iris_safer.bin")
  , identical(retrieve_object(conn = "iris_safer.bin"), iris)
  , unlink("iris_safer.bin") == 0
)

## [1] TRUE

all(
  save_object(iris, conn = "iris_safer_2.txt", ascii = TRUE)
  , identical(retrieve_object(conn = "iris_safer_2.txt", ascii = TRUE), iris)
  , unlink("iris_safer_2.txt") == 0
)

## [1] TRUE

# asymmetric case:
alice <- keypair()
bob   <- keypair()
all(
  save_object(iris, alice$private_key, bob$public_key, conn = "iris_safer.bin")
  , identical(retrieve_object(conn = "iris_safer.bin", bob$private_key, alice$public_key), iris)
  , unlink("iris_safer.bin") == 0
)

## [1] TRUE