discourse/lib/single_sign_on.rb

103 lines
2.8 KiB
Ruby

class SingleSignOn
ACCESSORS = [:nonce, :name, :username, :email, :avatar_url, :avatar_force_update, :require_activation,
:bio, :external_id, :return_sso_url, :admin, :moderator, :suppress_welcome_message, :title,
:add_groups, :remove_groups, :groups]
FIXNUMS = []
BOOLS = [:avatar_force_update, :admin, :moderator, :require_activation, :suppress_welcome_message]
ARRAYS = [:groups]
NONCE_EXPIRY_TIME = 10.minutes
attr_accessor(*ACCESSORS)
attr_writer :sso_secret, :sso_url
def self.sso_secret
raise RuntimeError, "sso_secret not implemented on class, be sure to set it on instance"
end
def self.sso_url
raise RuntimeError, "sso_url not implemented on class, be sure to set it on instance"
end
def self.parse(payload, sso_secret = nil)
sso = new
sso.sso_secret = sso_secret if sso_secret
parsed = Rack::Utils.parse_query(payload)
if sso.sign(parsed["sso"]) != parsed["sig"]
diags = "\n\nsso: #{parsed["sso"]}\n\nsig: #{parsed["sig"]}\n\nexpected sig: #{sso.sign(parsed["sso"])}"
if parsed["sso"] =~ /[^a-zA-Z0-9=\r\n\/+]/m
raise RuntimeError, "The SSO field should be Base64 encoded, using only A-Z, a-z, 0-9, +, /, and = characters. Your input contains characters we don't understand as Base64, see http://en.wikipedia.org/wiki/Base64 #{diags}"
else
raise RuntimeError, "Bad signature for payload #{diags}"
end
end
decoded = Base64.decode64(parsed["sso"])
decoded_hash = Rack::Utils.parse_query(decoded)
ACCESSORS.each do |k|
val = decoded_hash[k.to_s]
val = val.to_i if FIXNUMS.include? k
if BOOLS.include? k
val = ["true", "false"].include?(val) ? val == "true" : nil
end
val = Array(val) if ARRAYS.include?(k) && !val.nil?
sso.send("#{k}=", val)
end
decoded_hash.each do |k, v|
if field = k[/^custom\.(.+)$/, 1]
sso.custom_fields[field] = v
end
end
sso
end
def diagnostics
SingleSignOn::ACCESSORS.map { |a| "#{a}: #{send(a)}" }.join("\n")
end
def sso_secret
@sso_secret || self.class.sso_secret
end
def sso_url
@sso_url || self.class.sso_url
end
def custom_fields
@custom_fields ||= {}
end
def sign(payload)
OpenSSL::HMAC.hexdigest("sha256", sso_secret, payload)
end
def to_url(base_url = nil)
base = "#{base_url || sso_url}"
"#{base}#{base.include?('?') ? '&' : '?'}#{payload}"
end
def payload
payload = Base64.strict_encode64(unsigned_payload)
"sso=#{CGI::escape(payload)}&sig=#{sign(payload)}"
end
def unsigned_payload
payload = {}
ACCESSORS.each do |k|
next if (val = send k) == nil
payload[k] = val
end
@custom_fields&.each do |k, v|
payload["custom.#{k}"] = v.to_s
end
Rack::Utils.build_query(payload)
end
end