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require File.expand_path(File.dirname(__FILE__) + '/util')
module SRP
module Authentication
include Util
class Session
include Util
attr_accessor :aa, :bb
def initialize(aa, verifier)
@aa = aa
@b = bigrand(32).hex
# B = g^b + k v (mod N)
@bb = (modpow(GENERATOR, @b, PRIME_N) + multiplier * verifier) % PRIME_N
end
def u
calculate_u(aa, bb, PRIME_N)
end
# do not cache this - it's secret and someone might store the
# session in a CookieStore
def secret(verifier)
base = (modpow(verifier, u, PRIME_N) * aa) % PRIME_N
modpow(base, @b, PRIME_N)
end
def m1(verifier)
calculate_m(aa, bb, secret(verifier))
end
def m2(m1, verifier)
calculate_m(aa, m1, secret(verifier))
end
end
def initialize_auth(aa)
return Session.new(aa, verifier)
end
def authenticate(m, session)
if(m == session.m1(verifier))
return session.m2(m, verifier)
end
end
end
end
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