class RbNaCl::Hash::Blake2b
The Blake2b
hash function
Blake2b
is based on Blake, a SHA3 finalist which was snubbed in favor of Keccak, a much slower hash function but one sufficiently different from SHA2 to let the SHA3 judges panel sleep easy. Back in the real world, it'd be great if we can calculate hashes quickly if possible.
Blake2b
provides for up to 64-bit digests and also supports a keyed mode similar to HMAC
Constants
- EMPTY_PERSONAL
- EMPTY_SALT
Public Class Methods
Create a new Blake2b
hash object
@param [Hash] opts Blake2b
configuration @option opts [String] :key for Blake2b
keyed mode @option opts [Integer] :digest_size size of output digest in bytes @option opts [String] :salt Provide a salt to support randomised hashing.
This is mixed into the parameters block to start the hashing.
@option opts [Personal] :personal Provide personalisation string to allow pinning a hash for a particular purpose.
This is mixed into the parameters block to start the hashing
@raise [RbNaCl::LengthError] Invalid length specified for one or more options
@return [RbNaCl::Hash::Blake2b] A Blake2b
hasher object
# File lib/rbnacl/hash/blake2b.rb, line 47 def initialize(opts = {}) @key = opts.fetch(:key, nil) if @key @key_size = @key.bytesize raise LengthError, "key too short" if @key_size < KEYBYTES_MIN raise LengthError, "key too long" if @key_size > KEYBYTES_MAX else @key_size = 0 end @digest_size = opts.fetch(:digest_size, BYTES_MAX) raise LengthError, "digest size too short" if @digest_size < BYTES_MIN raise LengthError, "digest size too long" if @digest_size > BYTES_MAX @personal = opts.fetch(:personal, EMPTY_PERSONAL) @personal = Util.zero_pad(PERSONALBYTES, @personal) @salt = opts.fetch(:salt, EMPTY_SALT) @salt = Util.zero_pad(SALTBYTES, @salt) end
Public Instance Methods
Calculate a Blake2b
digest
@param [String] message Message to be hashed
@return [String] Blake2b
digest of the string as raw bytes
# File lib/rbnacl/hash/blake2b.rb, line 74 def digest(message) digest = Util.zeros(@digest_size) self.class.generichash_blake2b(digest, @digest_size, message, message.bytesize, @key, @key_size, @salt, @personal) || raise(CryptoError, "Hashing failed!") digest end