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httr2 provides a handful of functions designed for working with confidential data. These are useful because testing packages that use httr2 often requires some confidential data that needs to be available for testing, but should not be available to package users.

  • secret_encrypt() and secret_decrypt() work with individual strings

  • secret_encrypt_file() encrypts a file in place and secret_decrypt_file() decrypts a file in a temporary location.

  • secret_write_rds() and secret_read_rds() work with .rds files

  • secret_make_key() generates a random string to use as a key.

  • secret_has_key() returns TRUE if the key is available; you can use it in examples and vignettes that you want to evaluate on your CI, but not for CRAN/package users.

These all look for the key in an environment variable. When used inside of testthat, they will automatically testthat::skip() the test if the env var isn't found. (Outside of testthat, they'll error if the env var isn't found.)

Usage

secret_make_key()

secret_encrypt(x, key)

secret_decrypt(encrypted, key)

secret_write_rds(x, path, key)

secret_read_rds(path, key)

secret_decrypt_file(path, key, envir = parent.frame())

secret_encrypt_file(path, key)

secret_has_key(key)

Arguments

x

Object to encrypt. Must be a string for secret_encrypt().

key

Encryption key; this is the password that allows you to "lock" and "unlock" the secret. The easiest way to specify this is as the name of an environment variable. Alternatively, if you already have a base64url encoded string, you can wrap it in I(), or you can pass the raw vector in directly.

encrypted

String to decrypt

path

Path to file to encrypted file to read or write. For secret_write_rds() and secret_read_rds() this should be an .rds file.

envir

The decrypted file will be automatically deleted when this environment exits. You should only need to set this argument if you want to pass the unencrypted file to another function.

Value

  • secret_decrypt() and secret_encrypt() return strings.

  • secret_decrypt_file() returns a path to a temporary file; secret_encrypt_file() encrypts the file in place.

  • secret_write_rds() returns x invisibly; secret_read_rds() returns the saved object.

  • secret_make_key() returns a string with class AsIs.

  • secret_has_key() returns TRUE or FALSE.

Basic workflow

  1. Use secret_make_key() to generate a password. Make this available as an env var (e.g. {MYPACKAGE}_KEY) by adding a line to your .Renviron.

  2. Encrypt strings with secret_encrypt(), files with secret_encrypt_file(), and other data with secret_write_rds(), setting key = "{MYPACKAGE}_KEY".

  3. In your tests, decrypt the data with secret_decrypt(), secret_decrypt_file(), or secret_read_rds() to match how you encrypt it.

  4. If you push this code to your CI server, it will already "work" because all functions automatically skip tests when your {MYPACKAGE}_KEY env var isn't set. To make the tests actually run, you'll need to set the env var using whatever tool your CI system provides for setting env vars. Make sure to carefully inspect the test output to check that the skips have actually gone away.

Examples

key <- secret_make_key()

path <- tempfile()
secret_write_rds(mtcars, path, key = key)
secret_read_rds(path, key)
#>                      mpg cyl  disp  hp drat    wt  qsec vs am gear carb
#> Mazda RX4           21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
#> Mazda RX4 Wag       21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
#> Datsun 710          22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
#> Hornet 4 Drive      21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
#> Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
#> Valiant             18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
#> Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
#> Merc 240D           24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
#> Merc 230            22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
#> Merc 280            19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
#> Merc 280C           17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
#> Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
#> Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
#> Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
#> Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
#> Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
#> Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
#> Fiat 128            32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
#> Honda Civic         30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
#> Toyota Corolla      33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
#> Toyota Corona       21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
#> Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
#> AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
#> Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
#> Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
#> Fiat X1-9           27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
#> Porsche 914-2       26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
#> Lotus Europa        30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
#> Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
#> Ferrari Dino        19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
#> Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
#> Volvo 142E          21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2

# While you can manage the key explicitly in a variable, it's much
# easier to store in an environment variable. In real life, you should
# NEVER use `Sys.setenv()` to create this env var because you will
# also store the secret in your `.Rhistory`. Instead add it to your
# .Renviron using `usethis::edit_r_environ()` or similar.
Sys.setenv("MY_KEY" = key)

x <- secret_encrypt("This is a secret", "MY_KEY")
x
#> [1] "4KcRRrsowZ8ZCl-0O-NUauefQwzqi-pOS7fK48rjKfI"
secret_decrypt(x, "MY_KEY")
#> [1] "This is a secret"