digest: hmac – R documentation

Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!

hmac

compute a hash-based message authentication code

Description

The hmac function calculates a message authentication code (MAC) involving the specified cryptographic hash function in combination with a given secret key.

Usage

hmac(key, object,
     algo = c("md5", "sha1", "crc32", "sha256", "sha512"),
     serialize = FALSE, raw = FALSE, ...)

Arguments

`key`	An arbitrary character or numeric vector, to use as pre-shared secret key.
`object`	An arbitrary R object which will then be passed to the `serialize` function, unless the `serialize` argument is set to `FALSE`.
`algo`	The algorithms to be used; currently available choices are `md5`, which is also the default, `sha1`, `crc32` and `sha256`.
`serialize`	default value of `serialize` is here FALSE, not TRUE as it is in `digest`.
`raw`	This flag alters the type of the output. Setting this to `TRUE` causes the function to return an object of type `"raw"` instead of `"character"`.
`...`	All remaining arguments are passed to `digest`.

Value

The hmac function uses the digest to return a hash digest as specified in the RFC 2104.

Author(s)

Mario Frasca mfrasca@zonnet.nl.

References

MD5: https://www.ietf.org/rfc/rfc1321.txt.

SHA-1: https://en.wikipedia.org/wiki/SHA-1. SHA-256: https://csrc.nist.gov/publications/fips/fips180-2/fips180-2withchangenotice.pdf. CRC32: The original reference webpage at rocksoft.com has vanished from the web; see https://en.wikipedia.org/wiki/Cyclic_redundancy_check for general information on CRC algorithms.

https://aarongifford.com/computers/sha.html for the integrated C implementation of sha-512.

The page for the code underlying the C functions used here for sha-1 and md5, and further references, is no longer accessible. Please see https://en.wikipedia.org/wiki/SHA-1 and https://en.wikipedia.org/wiki/MD5.

https://zlib.net for documentation on the zlib library which supplied the code for crc32.

https://en.wikipedia.org/wiki/SHA_hash_functions for documentation on the sha functions.

Examples

## Standard RFC 2104 test vectors
current <- hmac('Jefe', 'what do ya want for nothing?', "md5")
target <- '750c783e6ab0b503eaa86e310a5db738'
stopifnot(identical(target, as.character(current)))

current <- hmac(rep(0x0b, 16), 'Hi There', "md5")
target <- '9294727a3638bb1c13f48ef8158bfc9d'
stopifnot(identical(target, as.character(current)))

current <- hmac(rep(0xaa, 16), rep(0xdd, 50), "md5")
target <- '56be34521d144c88dbb8c733f0e8b3f6'
stopifnot(identical(target, as.character(current)))

## SHA1 tests inspired to the RFC 2104 and checked against the python
## hmac implementation.
current <- hmac('Jefe', 'what do ya want for nothing?', "sha1")
target <- 'effcdf6ae5eb2fa2d27416d5f184df9c259a7c79'
stopifnot(identical(target, as.character(current)))

current <- hmac(rep(0x0b, 16), 'Hi There', "sha1")
target <- '675b0b3a1b4ddf4e124872da6c2f632bfed957e9'
stopifnot(identical(target, as.character(current)))

current <- hmac(rep(0xaa, 16), rep(0xdd, 50), "sha1")
target <- 'd730594d167e35d5956fd8003d0db3d3f46dc7bb'
stopifnot(identical(target, as.character(current)))

digest

Create Compact Hash Digests of R Objects

v0.6.27

GPL (>= 2)

Authors

Dirk Eddelbuettel <edd@debian.org> with contributions by Antoine Lucas, Jarek Tuszynski, Henrik Bengtsson, Simon Urbanek, Mario Frasca, Bryan Lewis, Murray Stokely, Hannes Muehleisen, Duncan Murdoch, Jim Hester, Wush Wu, Qiang Kou, Thierry Onkelinx, Michel Lang, Viliam Simko, Kurt Hornik, Radford Neal, Kendon Bell, Matthew de Queljoe, Ion Suruceanu, Bill Denney, Dirk Schumacher, and Winston Chang.

Initial release

2020-10-20