Hashes character or raw input with the self-contained SHA-512 (FIPS
180-4) in the compiled core and returns the digest as hex. A digest is a
fingerprint: any change to the input gives a different value, so it pins
a data file, a code string or a manifest. Use it over
csha256()
when a pin has to outlive the capsule by decades: the wider digest leaves
more margin, including against a quantum adversary, for whom Grover's
algorithm halves the effective preimage exponent.
Value
A character vector of 128-character lowercase hex digests: one
per element for character input (NA for NA), length 1 for
raw input.
Details
Character input is hashed element by element, each string as its bytes
(UTF-8 text gives the UTF-8 bytes; no newline is added). NA
elements give NA. Other atomic input (numbers, logicals) is first
converted with as.character(), so csha512(1) is the
digest of the text "1". A raw vector is hashed as one byte string.
For files use sha512file(). Pure computation; no side
effects.
Examples
# FIPS 180-4 test vector for "abc".
csha512("abc")
#> [1] "ddaf35a193617abacc417349ae20413112e6fa4e89a97ea20a9eeee64b55d39a2192992a274fc1a836ba3c23a3feebbd454d4423643ce80e2a9ac94fa54ca49f"
# Vectorised over character input; NA stays NA.
csha512(c("abc", "def", NA))
#> [1] "ddaf35a193617abacc417349ae20413112e6fa4e89a97ea20a9eeee64b55d39a2192992a274fc1a836ba3c23a3feebbd454d4423643ce80e2a9ac94fa54ca49f"
#> [2] "40a855bf0a93c1019d75dd5b59cd8157608811dd75c5977e07f3bc4be0cad98b22dde4db9ddb429fc2ad3cf9ca379fedf6c1dc4d4bb8829f10c2f0ee04a66663"
#> [3] NA
# Raw input hashes the bytes directly, and agrees with the character
# form for the same bytes.
identical(csha512("abc"), csha512(charToRaw("abc")))
#> [1] TRUE
# Twice the digest width of SHA-256.
c(sha256 = nchar(csha256("abc")), sha512 = nchar(csha512("abc")))
#> sha256 sha512
#> 64 128
# numbers are hashed as their text
identical(csha512(1), csha512("1"))
#> [1] TRUE