discourse/lib/single_sign_on.rb

153 lines
3.7 KiB
Ruby

class SingleSignOn
class ParseError < RuntimeError; end
ACCESSORS = %i{
add_groups
admin moderator
avatar_force_update
avatar_url
bio
card_background_url
email
external_id
groups
locale
locale_force_update
name
nonce
profile_background_url
remove_groups
require_activation
return_sso_url
suppress_welcome_message
title
username
website
}
FIXNUMS = []
BOOLS = %i{
admin
avatar_force_update
locale_force_update
moderator
require_activation
suppress_welcome_message
}
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
parsed = Rack::Utils.parse_query(payload)
decoded = Base64.decode64(parsed["sso"])
decoded_hash = Rack::Utils.parse_query(decoded)
return_sso_url = decoded_hash['return_sso_url']
sso.sso_secret = sso_secret || (provider_secret(return_sso_url) if return_sso_url)
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 ParseError, "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 ParseError, "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
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 self.provider_secret(return_sso_url)
provider_secrets = SiteSetting.sso_provider_secrets.split(/[|\n]/)
provider_secrets_hash = Hash[*provider_secrets]
return_url_host = URI.parse(return_sso_url).host
# moves wildcard domains to the end of hash
sorted_secrets = provider_secrets_hash.sort_by { |k, _| k }.reverse.to_h
secret = sorted_secrets.select do |domain, _|
WildcardDomainChecker.check_domain(domain, return_url_host)
end
secret.present? ? secret.values.first : nil
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, provider_secret = nil)
secret = provider_secret || sso_secret
OpenSSL::HMAC.hexdigest("sha256", secret, payload)
end
def to_url(base_url = nil)
base = "#{base_url || sso_url}"
"#{base}#{base.include?('?') ? '&' : '?'}#{payload}"
end
def payload(provider_secret = nil)
payload = Base64.strict_encode64(unsigned_payload)
"sso=#{CGI::escape(payload)}&sig=#{sign(payload, provider_secret)}"
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