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Base64 encoding

Source: R/json_native.R
rmbl_base64.Rd

Encodes and decodes base64, in both the standard alphabet and the URL-safe variant. Computed in R with no dependency, so a capsule can embed binary content in a text manifest wherever this package runs.

Usage

bricklayer_json_base64_enc(input)

bricklayer_json_base64_dec(input)

bricklayer_json_base64url_enc(input)

bricklayer_json_base64url_dec(input)

Arguments

input

For the encoders, a raw vector or a character vector (joined with newlines first). For the decoders, base64 text or its raw bytes.

Value

The encoders return a length-1 character vector ( NA_character_ for NULL input); the decoders return a raw vector.

Details

bricklayer_json_base64_enc() breaks its output into 72-character lines, matching jsonlite's encoder; the decoder ignores line breaks and any other character outside the alphabet, so either form round trips.

The URL-safe variant substitutes - and _ for + and / and drops the = padding, which is what makes it safe in a URL path, a query string or a filename.

Base64 is an ENCODING, not encryption or a digest: it hides nothing and anyone can reverse it. Use core_sha256() to pin content and core_hmac_sha256() to authenticate it.

See also

json_gzip_encode(), which composes this with gzip.

Examples

# Round trip through the standard alphabet.
b <- bricklayer_json_base64_enc("hello capsule")
b
#> [1] "aGVsbG8gY2Fwc3VsZQ=="
rawToChar(bricklayer_json_base64_dec(b))
#> [1] "hello capsule"

# Raw input works the same way.
bricklayer_json_base64_enc(charToRaw("abc"))
#> [1] "YWJj"
bricklayer_json_base64_dec(bricklayer_json_base64_enc(charToRaw("abc")))
#> [1] 61 62 63

# Padding appears when the length is not a multiple of three.
bricklayer_json_base64_enc("a")
#> [1] "YQ=="
bricklayer_json_base64_enc("ab")
#> [1] "YWI="
bricklayer_json_base64_enc("abc")
#> [1] "YWJj"

# The URL-safe variant has no "+", "/" or "=" to escape.
bricklayer_json_base64url_enc(as.raw(c(255, 224, 63)))
#> [1] "_-A_"
bricklayer_json_base64_enc(as.raw(c(255, 224, 63)))
#> [1] "/+A/"
bricklayer_json_base64url_dec(
  bricklayer_json_base64url_enc("path/safe?yes")
)
#>  [1] 70 61 74 68 2f 73 61 66 65 3f 79 65 73

# Long input is wrapped, and the decoder ignores the breaks.
long <- bricklayer_json_base64_enc(strrep("x", 200))
grepl("\n", long)
#> [1] TRUE
rawToChar(bricklayer_json_base64_dec(long)) == strrep("x", 200)
#> [1] TRUE