Sha256: 5d42ee63a61b1f0e8910a7d64dc93a6085c62523d112e03e230d2401e9400aab
Contents?: true
Size: 820 Bytes
Versions: 20
Compression:
Stored size: 820 Bytes
Contents
class Epics::MGF1
def initialize(digest = OpenSSL::Digest::SHA256)
@digest = digest.new
@hlen = 32
end
def generate(seed, masklen)
if masklen > (2 << 31) * @hlen
raise ArgumentError, "mask too long"
end
t = ""
divceil(masklen, @hlen).times do |counter|
t += @digest.digest(seed + i2osp(counter, 4))
end
t[0, masklen]
end
def i2osp(x, len)
if x >= 256 ** len
raise ArgumentError, "integer too large"
end
[x].pack("N").gsub(/^\x00+/, '').rjust(len, "\x00")
end
def divceil(a, b)
(a + b - 1) / b
end
def xor(a, b)
if a.size != b.size
raise ArgumentError, "different length for a and b"
end
a = a.unpack('C*')
b = b.unpack('C*')
a.size.times do |idx|
a[idx] ^= b[idx]
end
a.pack("C*")
end
end
Version data entries
20 entries across 20 versions & 1 rubygems