Merge remote-tracking branch 'origin/develop' into HEAD

1 files changed, 541 insertions, 0 deletions

diff --git a/lib/leap_cli/commands/ca.rb b/lib/leap_cli/commands/ca.rb
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+autoload :OpenSSL, 'openssl'
+autoload :CertificateAuthority, 'certificate_authority'
+autoload :Date, 'date'
+require 'digest/md5'
+
+module LeapCli; module Commands
+
+  desc "Manage X.509 certificates"
+  command :cert do |cert|
+
+    cert.desc 'Creates two Certificate Authorities (one for validating servers and one for validating clients).'
+    cert.long_desc 'See see what values are used in the generation of the certificates (like name and key size), run `leap inspect provider` and look for the "ca" property. To see the details of the created certs, run `leap inspect <file>`.'
+    cert.command :ca do |ca|
+      ca.action do |global_options,options,args|
+        assert_config! 'provider.ca.name'
+        generate_new_certificate_authority(:ca_key, :ca_cert, provider.ca.name)
+        generate_new_certificate_authority(:client_ca_key, :client_ca_cert, provider.ca.name + ' (client certificates only!)')
+      end
+    end
+
+    cert.desc 'Creates or renews a X.509 certificate/key pair for a single node or all nodes, but only if needed.'
+    cert.long_desc 'This command will a generate new certificate for a node if some value in the node has changed ' +
+                   'that is included in the certificate (like hostname or IP address), or if the old certificate will be expiring soon. ' +
+                   'Sometimes, you might want to force the generation of a new certificate, ' +
+                   'such as in the cases where you have changed a CA parameter for server certificates, like bit size or digest hash. ' +
+                   'In this case, use --force. If <node-filter> is empty, this command will apply to all nodes.'
+    cert.arg_name 'FILTER'
+    cert.command :update do |update|
+      update.switch 'force', :desc => 'Always generate new certificates', :negatable => false
+      update.action do |global_options,options,args|
+        update_certificates(manager.filter!(args), options)
+      end
+    end
+
+    cert.desc 'Creates a Diffie-Hellman parameter file, needed for forward secret OpenVPN ciphers.' # (needed for server-side of some TLS connections)
+    cert.command :dh do |dh|
+      dh.action do |global_options,options,args|
+        long_running do
+          if cmd_exists?('certtool')
+            log 0, 'Generating DH parameters (takes a long time)...'
+            output = assert_run!('certtool --generate-dh-params --sec-param high')
+            output.sub! /.*(-----BEGIN DH PARAMETERS-----.*-----END DH PARAMETERS-----).*/m, '\1'
+            output << "\n"
+            write_file!(:dh_params, output)
+          else
+            log 0, 'Generating DH parameters (takes a REALLY long time)...'
+            output = OpenSSL::PKey::DH.generate(3248).to_pem
+            write_file!(:dh_params, output)
+          end
+        end
+      end
+    end
+
+    #
+    # hints:
+    #
+    # inspect CSR:
+    #   openssl req -noout -text -in files/cert/x.csr
+    #
+    # generate CSR with openssl to see how it compares:
+    #   openssl req -sha256 -nodes -newkey rsa:2048 -keyout example.key -out example.csr
+    #
+    # validate a CSR:
+    #   http://certlogik.com/decoder/
+    #
+    # nice details about CSRs:
+    #   http://www.redkestrel.co.uk/Articles/CSR.html
+    #
+    cert.desc "Creates a CSR for use in buying a commercial X.509 certificate."
+    cert.long_desc "Unless specified, the CSR is created for the provider's primary domain. "+
+      "The properties used for this CSR come from `provider.ca.server_certificates`, "+
+      "but may be overridden here."
+    cert.command :csr do |csr|
+      csr.flag 'domain', :arg_name => 'DOMAIN', :desc => 'Specify what domain to create the CSR for.'
+      csr.flag ['organization', 'O'], :arg_name => 'ORGANIZATION', :desc => "Override default O in distinguished name."
+      csr.flag ['unit', 'OU'], :arg_name => 'UNIT', :desc => "Set OU in distinguished name."
+      csr.flag 'email', :arg_name => 'EMAIL', :desc => "Set emailAddress in distinguished name."
+      csr.flag ['locality', 'L'], :arg_name => 'LOCALITY', :desc => "Set L in distinguished name."
+      csr.flag ['state', 'ST'], :arg_name => 'STATE', :desc => "Set ST in distinguished name."
+      csr.flag ['country', 'C'], :arg_name => 'COUNTRY', :desc => "Set C in distinguished name."
+      csr.flag :bits, :arg_name => 'BITS', :desc => "Override default certificate bit length"
+      csr.flag :digest, :arg_name => 'DIGEST', :desc => "Override default signature digest"
+      csr.action do |global_options,options,args|
+        assert_config! 'provider.domain'
+        assert_config! 'provider.name'
+        assert_config! 'provider.default_language'
+        assert_config! 'provider.ca.server_certificates.bit_size'
+        assert_config! 'provider.ca.server_certificates.digest'
+        domain = options[:domain] || provider.domain
+
+        unless global_options[:force]
+          assert_files_missing! [:commercial_key, domain], [:commercial_csr, domain],
+            :msg => 'If you really want to create a new key and CSR, remove these files first or run with --force.'
+        end
+
+        server_certificates = provider.ca.server_certificates
+
+        # RSA key
+        keypair = CertificateAuthority::MemoryKeyMaterial.new
+        bit_size = (options[:bits] || server_certificates.bit_size).to_i
+        log :generating, "%s bit RSA key" % bit_size do
+          keypair.generate_key(bit_size)
+          write_file! [:commercial_key, domain], keypair.private_key.to_pem
+        end
+
+        # CSR
+        dn  = CertificateAuthority::DistinguishedName.new
+        dn.common_name   = domain
+        dn.organization  = options[:organization] || provider.name[provider.default_language]
+        dn.ou            = options[:organizational_unit] # optional
+        dn.email_address = options[:email] # optional
+        dn.country       = options[:country] || server_certificates['country']   # optional
+        dn.state         = options[:state] || server_certificates['state']       # optional
+        dn.locality      = options[:locality] || server_certificates['locality'] # optional
+
+        digest = options[:digest] || server_certificates.digest
+        log :generating, "CSR with #{digest} digest and #{print_dn(dn)}" do
+          csr = create_csr(dn, keypair, digest)
+          request = csr.to_x509_csr
+          write_file! [:commercial_csr, domain], csr.to_pem
+        end
+
+        # Sign using our own CA, for use in testing but hopefully not production.
+        # It is not that commerical CAs are so secure, it is just that signing your own certs is
+        # a total drag for the user because they must click through dire warnings.
+        #if options[:sign]
+          log :generating, "self-signed x509 server certificate for testing purposes" do
+            cert = csr.to_cert
+            cert.serial_number.number = cert_serial_number(domain)
+            cert.not_before = yesterday
+            cert.not_after  = yesterday.advance(:years => 1)
+            cert.parent = ca_root
+            cert.sign! domain_test_signing_profile
+            write_file! [:commercial_cert, domain], cert.to_pem
+            log "please replace this file with the real certificate you get from a CA using #{Path.relative_path([:commercial_csr, domain])}"
+          end
+        #end
+
+        # FAKE CA
+        unless file_exists? :commercial_ca_cert
+          log :using, "generated CA in place of commercial CA for testing purposes" do
+            write_file! :commercial_ca_cert, read_file!(:ca_cert)
+            log "please also replace this file with the CA cert from the commercial authority you use."
+          end
+        end
+      end
+    end
+  end
+
+  protected
+
+  #
+  # will generate new certificates for the specified nodes, if needed.
+  #
+  def update_certificates(nodes, options={})
+    assert_files_exist! :ca_cert, :ca_key, :msg => 'Run `leap cert ca` to create them'
+    assert_config! 'provider.ca.server_certificates.bit_size'
+    assert_config! 'provider.ca.server_certificates.digest'
+    assert_config! 'provider.ca.server_certificates.life_span'
+    assert_config! 'common.x509.use'
+
+    nodes.each_node do |node|
+      warn_if_commercial_cert_will_soon_expire(node)
+      if !node.x509.use
+        remove_file!([:node_x509_key, node.name])
+        remove_file!([:node_x509_cert, node.name])
+      elsif options[:force] || cert_needs_updating?(node)
+        generate_cert_for_node(node)
+      end
+    end
+  end
+
+  private
+
+  def generate_new_certificate_authority(key_file, cert_file, common_name)
+    assert_files_missing! key_file, cert_file
+    assert_config! 'provider.ca.name'
+    assert_config! 'provider.ca.bit_size'
+    assert_config! 'provider.ca.life_span'
+
+    root = CertificateAuthority::Certificate.new
+
+    # set subject
+    root.subject.common_name = common_name
+    possible = ['country', 'state', 'locality', 'organization', 'organizational_unit', 'email_address']
+    provider.ca.keys.each do |key|
+      if possible.include?(key)
+        root.subject.send(key + '=', provider.ca[key])
+      end
+    end
+
+    # set expiration
+    root.not_before = yesterday
+    root.not_after = yesterday_advance(provider.ca.life_span)
+
+    # generate private key
+    root.serial_number.number = 1
+    root.key_material.generate_key(provider.ca.bit_size)
+
+    # sign self
+    root.signing_entity = true
+    root.parent = root
+    root.sign!(ca_root_signing_profile)
+
+    # save
+    write_file!(key_file, root.key_material.private_key.to_pem)
+    write_file!(cert_file, root.to_pem)
+  end
+
+  #
+  # returns true if the certs associated with +node+ need to be regenerated.
+  #
+  def cert_needs_updating?(node)
+    if !file_exists?([:node_x509_cert, node.name], [:node_x509_key, node.name])
+      return true
+    else
+      cert = load_certificate_file([:node_x509_cert, node.name])
+      if !created_by_authority?(cert, ca_root)
+        log :updating, "cert for node '#{node.name}' because it was signed by an old CA root cert."
+        return true
+      end
+      if cert.not_after < Time.now.advance(:months => 2)
+        log :updating, "cert for node '#{node.name}' because it will expire soon"
+        return true
+      end
+      if cert.subject.common_name != node.domain.full
+        log :updating, "cert for node '#{node.name}' because domain.full has changed (was #{cert.subject.common_name}, now #{node.domain.full})"
+        return true
+      end
+      cert.openssl_body.extensions.each do |ext|
+        if ext.oid == "subjectAltName"
+          ips = []
+          dns_names = []
+          ext.value.split(",").each do |value|
+            value.strip!
+            ips << $1          if value =~ /^IP Address:(.*)$/
+            dns_names << $1    if value =~ /^DNS:(.*)$/
+          end
+          dns_names.sort!
+          if ips.first != node.ip_address
+            log :updating, "cert for node '#{node.name}' because ip_address has changed (from #{ips.first} to #{node.ip_address})"
+            return true
+          elsif dns_names != dns_names_for_node(node)
+            log :updating, "cert for node '#{node.name}' because domain name aliases have changed\n    from: #{dns_names.inspect}\n    to: #{dns_names_for_node(node).inspect})"
+            return true
+          end
+        end
+      end
+    end
+    return false
+  end
+
+  def created_by_authority?(cert, ca)
+    authority_key_id = cert.extensions["authorityKeyIdentifier"].identifier.sub(/^keyid:/, '')
+    authority_key_id == public_key_id_for_ca(ca)
+  end
+
+  # calculate the "key id" for a root CA, that matches the value
+  # Authority Key Identifier in the x509 extensions of a cert.
+  def public_key_id_for_ca(ca_cert)
+    @ca_key_ids ||= {}
+    @ca_key_ids[ca_cert.object_id] ||= begin
+      pubkey = ca_cert.key_material.public_key
+      seq = OpenSSL::ASN1::Sequence([
+        OpenSSL::ASN1::Integer.new(pubkey.n),
+        OpenSSL::ASN1::Integer.new(pubkey.e)
+      ])
+      Digest::SHA1.hexdigest(seq.to_der).upcase.scan(/../).join(':')
+    end
+  end
+
+  def warn_if_commercial_cert_will_soon_expire(node)
+    dns_names_for_node(node).each do |domain|
+      if file_exists?([:commercial_cert, domain])
+        cert = load_certificate_file([:commercial_cert, domain])
+        path = Path.relative_path([:commercial_cert, domain])
+        if cert.not_after < Time.now.utc
+          log :error, "the commercial certificate '#{path}' has EXPIRED! " +
+            "You should renew it with `leap cert csr --domain #{domain}`."
+        elsif cert.not_after < Time.now.advance(:months => 2)
+          log :warning, "the commercial certificate '#{path}' will expire soon. "+
+            "You should renew it with `leap cert csr --domain #{domain}`."
+        end
+      end
+    end
+  end
+
+  def generate_cert_for_node(node)
+    return if node.x509.use == false
+
+    cert = CertificateAuthority::Certificate.new
+
+    # set subject
+    cert.subject.common_name = node.domain.full
+    cert.serial_number.number = cert_serial_number(node.domain.full)
+
+    # set expiration
+    cert.not_before = yesterday
+    cert.not_after = yesterday_advance(provider.ca.server_certificates.life_span)
+
+    # generate key
+    cert.key_material.generate_key(provider.ca.server_certificates.bit_size)
+
+    # sign
+    cert.parent = ca_root
+    cert.sign!(server_signing_profile(node))
+
+    # save
+    write_file!([:node_x509_key, node.name], cert.key_material.private_key.to_pem)
+    write_file!([:node_x509_cert, node.name], cert.to_pem)
+  end
+
+  #
+  # yields client key and cert suitable for testing
+  #
+  def generate_test_client_cert(prefix=nil)
+    cert = CertificateAuthority::Certificate.new
+    cert.serial_number.number = cert_serial_number(provider.domain)
+    cert.subject.common_name = [prefix, random_common_name(provider.domain)].join
+    cert.not_before = yesterday
+    cert.not_after  = yesterday.advance(:years => 1)
+    cert.key_material.generate_key(1024) # just for testing, remember!
+    cert.parent = client_ca_root
+    cert.sign! client_test_signing_profile
+    yield cert.key_material.private_key.to_pem, cert.to_pem
+  end
+
+  #
+  # creates a CSR and returns it.
+  # with the correct extReq attribute so that the CA
+  # doens't generate certs with extensions we don't want.
+  #
+  def create_csr(dn, keypair, digest)
+    csr = CertificateAuthority::SigningRequest.new
+    csr.distinguished_name = dn
+    csr.key_material = keypair
+    csr.digest = digest
+
+    # define extensions manually (library doesn't support setting these on CSRs)
+    extensions = []
+    extensions << CertificateAuthority::Extensions::BasicConstraints.new.tap {|basic|
+      basic.ca = false
+    }
+    extensions << CertificateAuthority::Extensions::KeyUsage.new.tap {|keyusage|
+      keyusage.usage = ["digitalSignature", "keyEncipherment"]
+    }
+    extensions << CertificateAuthority::Extensions::ExtendedKeyUsage.new.tap {|extkeyusage|
+      extkeyusage.usage = [ "serverAuth"]
+    }
+
+    # convert extensions to attribute 'extReq'
+    # aka "Requested Extensions"
+    factory = OpenSSL::X509::ExtensionFactory.new
+    attrval = OpenSSL::ASN1::Set([OpenSSL::ASN1::Sequence(
+      extensions.map{|e| factory.create_ext(e.openssl_identifier, e.to_s, e.critical)}
+    )])
+    attrs = [
+      OpenSSL::X509::Attribute.new("extReq", attrval),
+    ]
+    csr.attributes = attrs
+
+    return csr
+  end
+
+  def ca_root
+    @ca_root ||= begin
+      load_certificate_file(:ca_cert, :ca_key)
+    end
+  end
+
+  def client_ca_root
+    @client_ca_root ||= begin
+      load_certificate_file(:client_ca_cert, :client_ca_key)
+    end
+  end
+
+  def load_certificate_file(crt_file, key_file=nil, password=nil)
+    crt = read_file!(crt_file)
+    openssl_cert = OpenSSL::X509::Certificate.new(crt)
+    cert = CertificateAuthority::Certificate.from_openssl(openssl_cert)
+    if key_file
+      key = read_file!(key_file)
+      cert.key_material.private_key = OpenSSL::PKey::RSA.new(key, password)
+    end
+    return cert
+  end
+
+  def ca_root_signing_profile
+    {
+      "extensions" => {
+        "basicConstraints" => {"ca" => true},
+        "keyUsage" => {
+          "usage" => ["critical", "keyCertSign"]
+        },
+        "extendedKeyUsage" => {
+          "usage" => []
+        }
+      }
+    }
+  end
+
+  #
+  # For keyusage, openvpn server certs can have keyEncipherment or keyAgreement.
+  # Web browsers seem to break without keyEncipherment.
+  # For now, I am using digitalSignature + keyEncipherment
+  #
+  # * digitalSignature -- for (EC)DHE cipher suites
+  #   "The digitalSignature bit is asserted when the subject public key is used
+  #    with a digital signature mechanism to support security services other
+  #    than certificate signing (bit 5), or CRL signing (bit 6). Digital
+  #    signature mechanisms are often used for entity authentication and data
+  #    origin authentication with integrity."
+  #
+  # * keyEncipherment  ==> for plain RSA cipher suites
+  #   "The keyEncipherment bit is asserted when the subject public key is used for
+  #    key transport. For example, when an RSA key is to be used for key management,
+  #    then this bit is set."
+  #
+  # * keyAgreement     ==> for used with DH, not RSA.
+  #   "The keyAgreement bit is asserted when the subject public key is used for key
+  #    agreement. For example, when a Diffie-Hellman key is to be used for key
+  #    management, then this bit is set."
+  #
+  # digest options: SHA512, SHA256, SHA1
+  #
+  def server_signing_profile(node)
+    {
+      "digest" => provider.ca.server_certificates.digest,
+      "extensions" => {
+        "keyUsage" => {
+          "usage" => ["digitalSignature", "keyEncipherment"]
+        },
+        "extendedKeyUsage" => {
+          "usage" => ["serverAuth", "clientAuth"]
+        },
+        "subjectAltName" => {
+          "ips" => [node.ip_address],
+          "dns_names" => dns_names_for_node(node)
+        }
+      }
+    }
+  end
+
+  #
+  # This is used when signing the main cert for the provider's domain
+  # with our own CA (for testing purposes). Typically, this cert would
+  # be purchased from a commercial CA, and not signed this way.
+  #
+  def domain_test_signing_profile
+    {
+      "digest" => "SHA256",
+      "extensions" => {
+        "keyUsage" => {
+          "usage" => ["digitalSignature", "keyEncipherment"]
+        },
+        "extendedKeyUsage" => {
+          "usage" => ["serverAuth"]
+        }
+      }
+    }
+  end
+
+  #
+  # This is used when signing a dummy client certificate that is only to be
+  # used for testing.
+  #
+  def client_test_signing_profile
+    {
+      "digest" => "SHA256",
+      "extensions" => {
+        "keyUsage" => {
+          "usage" => ["digitalSignature"]
+        },
+        "extendedKeyUsage" => {
+          "usage" => ["clientAuth"]
+        }
+      }
+    }
+  end
+
+  def dns_names_for_node(node)
+    names = [node.domain.internal, node.domain.full]
+    if node['dns'] && node.dns['aliases'] && node.dns.aliases.any?
+      names += node.dns.aliases
+    end
+    names.compact!
+    names.sort!
+    names.uniq!
+    return names
+  end
+
+  #
+  # For cert serial numbers, we need a non-colliding number less than 160 bits.
+  # md5 will do nicely, since there is no need for a secure hash, just a short one.
+  # (md5 is 128 bits)
+  #
+  def cert_serial_number(domain_name)
+    Digest::MD5.hexdigest("#{domain_name} -- #{Time.now}").to_i(16)
+  end
+
+  #
+  # for the random common name, we need a text string that will be unique across all certs.
+  # ruby 1.8 doesn't have a built-in uuid generator, or we would use SecureRandom.uuid
+  #
+  def random_common_name(domain_name)
+    cert_serial_number(domain_name).to_s(36)
+  end
+
+  # prints CertificateAuthority::DistinguishedName fields
+  def print_dn(dn)
+    fields = {}
+    [:common_name, :locality, :state, :country, :organization, :organizational_unit, :email_address].each do |attr|
+      fields[attr] = dn.send(attr) if dn.send(attr)
+    end
+    fields.inspect
+  end
+
+  ##
+  ## TIME HELPERS
+  ##
+  ## note: we use 'yesterday' instead of 'today', because times are in UTC, and some people on the planet
+  ## are behind UTC.
+  ##
+
+  def yesterday
+    t = Time.now - 24*24*60
+    Time.utc t.year, t.month, t.day
+  end
+
+  def yesterday_advance(string)
+    number, unit = string.split(' ')
+    unless ['years', 'months', 'days', 'hours', 'minutes'].include? unit
+      bail!("The time property '#{string}' is missing a unit (one of: years, months, days, hours, minutes).")
+    end
+    unless number.to_i.to_s == number
+      bail!("The time property '#{string}' is missing a number.")
+    end
+    yesterday.advance(unit.to_sym => number.to_i)
+  end
+
+end; end