JezK
Edit File: cram_md5.rb
# frozen_string_literal: true require "digest/md5" # Authenticator for the "+CRAM-MD5+" SASL mechanism, specified in # RFC2195[https://tools.ietf.org/html/rfc2195]. See Net::IMAP#authenticate. # # == Deprecated # # +CRAM-MD5+ is obsolete and insecure. It is included for compatibility with # existing servers. # {draft-ietf-sasl-crammd5-to-historic}[https://tools.ietf.org/html/draft-ietf-sasl-crammd5-to-historic-00.html] # recommends using +SCRAM-*+ or +PLAIN+ protected by TLS instead. # # Additionally, RFC8314[https://tools.ietf.org/html/rfc8314] discourage the use # of cleartext and recommends TLS version 1.2 or greater be used for all # traffic. With TLS +CRAM-MD5+ is okay, but so is +PLAIN+ class Net::IMAP::CramMD5Authenticator def process(challenge) digest = hmac_md5(challenge, @password) return @user + " " + digest end private def initialize(user, password) @user = user @password = password end def hmac_md5(text, key) if key.length > 64 key = Digest::MD5.digest(key) end k_ipad = key + "\0" * (64 - key.length) k_opad = key + "\0" * (64 - key.length) for i in 0..63 k_ipad[i] = (k_ipad[i].ord ^ 0x36).chr k_opad[i] = (k_opad[i].ord ^ 0x5c).chr end digest = Digest::MD5.digest(k_ipad + text) return Digest::MD5.hexdigest(k_opad + digest) end Net::IMAP.add_authenticator "CRAM-MD5", self end