For testing: add a KDM formulation which omits AuthorizedDeviceInfo.
[libdcp.git] / src / encrypted_kdm.cc
index be22ca5b00fd994d63e94d56c00ccc78078e73dc..80c5e2ef9f9c4c4fa27eb534c8515c5daef59502 100644 (file)
@@ -1,53 +1,70 @@
 /*
-    Copyright (C) 2013-2014 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2016 Carl Hetherington <cth@carlh.net>
 
-    This program is free software; you can redistribute it and/or modify
+    This file is part of libdcp.
+
+    libdcp is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.
 
-    This program is distributed in the hope that it will be useful,
+    libdcp is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
+    along with libdcp.  If not, see <http://www.gnu.org/licenses/>.
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of portions of this program with the
+    OpenSSL library under certain conditions as described in each
+    individual source file, and distribute linked combinations
+    including the two.
+
+    You must obey the GNU General Public License in all respects
+    for all of the code used other than OpenSSL.  If you modify
+    file(s) with this exception, you may extend this exception to your
+    version of the file(s), but you are not obligated to do so.  If you
+    do not wish to do so, delete this exception statement from your
+    version.  If you delete this exception statement from all source
+    files in the program, then also delete it here.
 */
 
 #include "encrypted_kdm.h"
 #include "util.h"
-#include "signer.h"
+#include "certificate_chain.h"
 #include <libcxml/cxml.h>
 #include <libxml++/document.h>
 #include <libxml++/nodes/element.h>
 #include <libxml/parser.h>
 #include <boost/date_time/posix_time/posix_time.hpp>
+#include <boost/foreach.hpp>
 
 using std::list;
+using std::vector;
 using std::string;
 using std::map;
 using std::pair;
 using boost::shared_ptr;
+using boost::optional;
 using namespace dcp;
 
 namespace dcp {
 
-/** Namespace for classes used to hold our data; they are internal to this .cc file */ 
+/** Namespace for classes used to hold our data; they are internal to this .cc file */
 namespace data {
 
 class Signer
 {
 public:
        Signer () {}
-       
-       Signer (shared_ptr<const cxml::Node> node)
+
+       explicit Signer (shared_ptr<const cxml::Node> node)
                : x509_issuer_name (node->string_child ("X509IssuerName"))
                , x509_serial_number (node->string_child ("X509SerialNumber"))
        {
-               
+
        }
 
        void as_xml (xmlpp::Element* node) const
@@ -55,7 +72,7 @@ public:
                node->add_child("X509IssuerName", "ds")->add_child_text (x509_issuer_name);
                node->add_child("X509SerialNumber", "ds")->add_child_text (x509_serial_number);
        }
-       
+
        string x509_issuer_name;
        string x509_serial_number;
 };
@@ -64,8 +81,8 @@ class X509Data
 {
 public:
        X509Data () {}
-       
-       X509Data (boost::shared_ptr<const cxml::Node> node)
+
+       explicit X509Data (boost::shared_ptr<const cxml::Node> node)
                : x509_issuer_serial (Signer (node->node_child ("X509IssuerSerial")))
                , x509_certificate (node->string_child ("X509Certificate"))
        {
@@ -77,34 +94,34 @@ public:
                x509_issuer_serial.as_xml (node->add_child ("X509IssuerSerial", "ds"));
                node->add_child("X509Certificate", "ds")->add_child_text (x509_certificate);
        }
-       
+
        Signer x509_issuer_serial;
        std::string x509_certificate;
 };
-       
+
 class Reference
 {
 public:
        Reference () {}
-       
-       Reference (string u)
+
+       explicit Reference (string u)
                : uri (u)
        {}
 
-       Reference (shared_ptr<const cxml::Node> node)
+       explicit Reference (shared_ptr<const cxml::Node> node)
                : uri (node->string_attribute ("URI"))
                , digest_value (node->string_child ("DigestValue"))
        {
 
        }
-       
+
        void as_xml (xmlpp::Element* node) const
        {
                node->set_attribute ("URI", uri);
                node->add_child("DigestMethod", "ds")->set_attribute ("Algorithm", "http://www.w3.org/2001/04/xmlenc#sha256");
                node->add_child("DigestValue", "ds")->add_child_text (digest_value);
        }
-       
+
        string uri;
        string digest_value;
 };
@@ -117,7 +134,7 @@ public:
                , authenticated_private ("#ID_AuthenticatedPrivate")
        {}
 
-       SignedInfo (shared_ptr<const cxml::Node> node)
+       explicit SignedInfo (shared_ptr<const cxml::Node> node)
        {
                list<shared_ptr<cxml::Node> > references = node->node_children ("Reference");
                for (list<shared_ptr<cxml::Node> >::const_iterator i = references.begin(); i != references.end(); ++i) {
@@ -140,22 +157,22 @@ public:
                node->add_child ("SignatureMethod", "ds")->set_attribute (
                        "Algorithm", "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"
                        );
-               
+
                authenticated_public.as_xml (node->add_child ("Reference", "ds"));
                authenticated_private.as_xml (node->add_child ("Reference", "ds"));
        }
-               
+
 private:
        Reference authenticated_public;
        Reference authenticated_private;
 };
-       
+
 class Signature
 {
 public:
        Signature () {}
 
-       Signature (shared_ptr<const cxml::Node> node)
+       explicit Signature (shared_ptr<const cxml::Node> node)
                : signed_info (node->node_child ("SignedInfo"))
                , signature_value (node->string_child ("SignatureValue"))
        {
@@ -169,7 +186,7 @@ public:
        {
                signed_info.as_xml (node->add_child ("SignedInfo", "ds"));
                node->add_child("SignatureValue", "ds")->add_child_text (signature_value);
-               
+
                xmlpp::Element* key_info_node = node->add_child ("KeyInfo", "ds");
                for (std::list<X509Data>::const_iterator i = x509_data.begin(); i != x509_data.end(); ++i) {
                        i->as_xml (key_info_node->add_child ("X509Data", "ds"));
@@ -185,8 +202,8 @@ class AuthenticatedPrivate
 {
 public:
        AuthenticatedPrivate () {}
-       
-       AuthenticatedPrivate (shared_ptr<const cxml::Node> node)
+
+       explicit AuthenticatedPrivate (shared_ptr<const cxml::Node> node)
        {
                list<shared_ptr<cxml::Node> > encrypted_key_nodes = node->node_children ("EncryptedKey");
                for (list<shared_ptr<cxml::Node> >::const_iterator i = encrypted_key_nodes.begin(); i != encrypted_key_nodes.end(); ++i) {
@@ -200,15 +217,19 @@ public:
 
                for (list<string>::const_iterator i = encrypted_key.begin(); i != encrypted_key.end(); ++i) {
                        xmlpp::Element* encrypted_key = node->add_child ("EncryptedKey", "enc");
+                       /* XXX: hack for testing with Dolby */
+                       encrypted_key->set_namespace_declaration ("http://www.w3.org/2001/04/xmlenc#", "enc");
                        xmlpp::Element* encryption_method = encrypted_key->add_child ("EncryptionMethod", "enc");
                        encryption_method->set_attribute ("Algorithm", "http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p");
                        xmlpp::Element* digest_method = encryption_method->add_child ("DigestMethod", "ds");
+                       /* XXX: hack for testing with Dolby */
+                       digest_method->set_namespace_declaration ("http://www.w3.org/2000/09/xmldsig#", "ds");
                        digest_method->set_attribute ("Algorithm", "http://www.w3.org/2000/09/xmldsig#sha1");
                        xmlpp::Element* cipher_data = encrypted_key->add_child ("CipherData", "enc");
                        cipher_data->add_child("CipherValue", "enc")->add_child_text (*i);
                }
        }
-       
+
        list<string> encrypted_key;
 };
 
@@ -216,10 +237,10 @@ class TypedKeyId
 {
 public:
        TypedKeyId () {}
-       
-       TypedKeyId (shared_ptr<const cxml::Node> node)
+
+       explicit TypedKeyId (shared_ptr<const cxml::Node> node)
                : key_type (node->string_child ("KeyType"))
-               , key_id (node->string_child ("KeyId").substr (9))
+               , key_id (remove_urn_uuid (node->string_child ("KeyId")))
        {
 
        }
@@ -231,8 +252,13 @@ public:
 
        void as_xml (xmlpp::Element* node) const
        {
-               node->add_child("KeyType")->add_child_text (key_type);
+               xmlpp::Element* type = node->add_child("KeyType");
+               type->add_child_text (key_type);
                node->add_child("KeyId")->add_child_text ("urn:uuid:" + key_id);
+               /* XXX: this feels like a bit of a hack */
+               if (key_type == "MDEK") {
+                       type->set_attribute ("scope", "http://www.dolby.com/cp850/2012/KDM#kdm-key-type");
+               }
        }
 
        string key_type;
@@ -243,8 +269,8 @@ class KeyIdList
 {
 public:
        KeyIdList () {}
-       
-       KeyIdList (shared_ptr<const cxml::Node> node)
+
+       explicit KeyIdList (shared_ptr<const cxml::Node> node)
        {
                list<shared_ptr<cxml::Node> > typed_key_id_nodes = node->node_children ("TypedKeyId");
                for (list<shared_ptr<cxml::Node> >::const_iterator i = typed_key_id_nodes.begin(); i != typed_key_id_nodes.end(); ++i) {
@@ -266,34 +292,40 @@ class AuthorizedDeviceInfo
 {
 public:
        AuthorizedDeviceInfo () {}
-       
-       AuthorizedDeviceInfo (shared_ptr<const cxml::Node> node)
-               : device_list_identifier (node->string_child ("DeviceListIdentifier").substr (9))
-               , device_list_description (node->string_child ("DeviceListDescription"))
-               , certificate_thumbprint (node->node_child("DeviceList")->string_child ("CertificateThumbprint"))
-       {
 
+       explicit AuthorizedDeviceInfo (shared_ptr<const cxml::Node> node)
+               : device_list_identifier (remove_urn_uuid (node->string_child ("DeviceListIdentifier")))
+               , device_list_description (node->optional_string_child ("DeviceListDescription"))
+       {
+               BOOST_FOREACH (cxml::ConstNodePtr i, node->node_child("DeviceList")->node_children("CertificateThumbprint")) {
+                       certificate_thumbprints.push_back (i->content ());
+               }
        }
 
        void as_xml (xmlpp::Element* node) const
        {
                node->add_child ("DeviceListIdentifier")->add_child_text ("urn:uuid:" + device_list_identifier);
-               node->add_child ("DeviceListDescription")->add_child_text (device_list_description);
+               if (device_list_description) {
+                       node->add_child ("DeviceListDescription")->add_child_text (device_list_description.get());
+               }
                xmlpp::Element* device_list = node->add_child ("DeviceList");
-               device_list->add_child("CertificateThumbprint")->add_child_text (certificate_thumbprint);
+               BOOST_FOREACH (string i, certificate_thumbprints) {
+                       device_list->add_child("CertificateThumbprint")->add_child_text (i);
+               }
        }
-       
+
+       /** DeviceListIdentifier without the urn:uuid: prefix */
        string device_list_identifier;
-       string device_list_description;
-       string certificate_thumbprint;
+       boost::optional<string> device_list_description;
+       std::list<string> certificate_thumbprints;
 };
 
 class X509IssuerSerial
 {
 public:
        X509IssuerSerial () {}
-       
-       X509IssuerSerial (shared_ptr<const cxml::Node> node)
+
+       explicit X509IssuerSerial (shared_ptr<const cxml::Node> node)
                : x509_issuer_name (node->string_child ("X509IssuerName"))
                , x509_serial_number (node->string_child ("X509SerialNumber"))
        {
@@ -314,8 +346,8 @@ class Recipient
 {
 public:
        Recipient () {}
-       
-       Recipient (shared_ptr<const cxml::Node> node)
+
+       explicit Recipient (shared_ptr<const cxml::Node> node)
                : x509_issuer_serial (node->node_child ("X509IssuerSerial"))
                , x509_subject_name (node->string_child ("X509SubjectName"))
        {
@@ -327,7 +359,7 @@ public:
                x509_issuer_serial.as_xml (node->add_child ("X509IssuerSerial"));
                node->add_child("X509SubjectName")->add_child_text (x509_subject_name);
        }
-       
+
        X509IssuerSerial x509_issuer_serial;
        string x509_subject_name;
 };
@@ -336,10 +368,10 @@ class KDMRequiredExtensions
 {
 public:
        KDMRequiredExtensions () {}
-       
-       KDMRequiredExtensions (shared_ptr<const cxml::Node> node)
+
+       explicit KDMRequiredExtensions (shared_ptr<const cxml::Node> node)
                : recipient (node->node_child ("Recipient"))
-               , composition_playlist_id (node->string_child ("CompositionPlaylistId").substr (9))
+               , composition_playlist_id (remove_urn_uuid (node->string_child ("CompositionPlaylistId")))
                , content_title_text (node->string_child ("ContentTitleText"))
                , not_valid_before (node->string_child ("ContentKeysNotValidBefore"))
                , not_valid_after (node->string_child ("ContentKeysNotValidAfter"))
@@ -352,30 +384,32 @@ public:
        void as_xml (xmlpp::Element* node) const
        {
                node->set_attribute ("xmlns", "http://www.smpte-ra.org/schemas/430-1/2006/KDM");
-               
+
                recipient.as_xml (node->add_child ("Recipient"));
                node->add_child("CompositionPlaylistId")->add_child_text ("urn:uuid:" + composition_playlist_id);
+               node->add_child("ContentTitleText")->add_child_text (content_title_text);
                if (content_authenticator) {
                        node->add_child("ContentAuthenticator")->add_child_text (content_authenticator.get ());
                }
-               node->add_child("ContentTitleText")->add_child_text (content_title_text);
                node->add_child("ContentKeysNotValidBefore")->add_child_text (not_valid_before.as_string ());
                node->add_child("ContentKeysNotValidAfter")->add_child_text (not_valid_after.as_string ());
-               authorized_device_info.as_xml (node->add_child ("AuthorizedDeviceInfo"));
+               if (authorized_device_info) {
+                       authorized_device_info->as_xml (node->add_child ("AuthorizedDeviceInfo"));
+               }
                key_id_list.as_xml (node->add_child ("KeyIdList"));
-               
+
                xmlpp::Element* forensic_mark_flag_list = node->add_child ("ForensicMarkFlagList");
                forensic_mark_flag_list->add_child("ForensicMarkFlag")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#mrkflg-picture-disable");
                forensic_mark_flag_list->add_child("ForensicMarkFlag")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#mrkflg-audio-disable");
        }
-       
+
        Recipient recipient;
        string composition_playlist_id;
        boost::optional<string> content_authenticator;
        string content_title_text;
        LocalTime not_valid_before;
        LocalTime not_valid_after;
-       AuthorizedDeviceInfo authorized_device_info;
+       boost::optional<AuthorizedDeviceInfo> authorized_device_info;
        KeyIdList key_id_list;
 };
 
@@ -383,8 +417,8 @@ class RequiredExtensions
 {
 public:
        RequiredExtensions () {}
-       
-       RequiredExtensions (shared_ptr<const cxml::Node> node)
+
+       explicit RequiredExtensions (shared_ptr<const cxml::Node> node)
                : kdm_required_extensions (node->node_child ("KDMRequiredExtensions"))
        {
 
@@ -394,7 +428,7 @@ public:
        {
                kdm_required_extensions.as_xml (node->add_child ("KDMRequiredExtensions"));
        }
-       
+
        KDMRequiredExtensions kdm_required_extensions;
 };
 
@@ -403,12 +437,14 @@ class AuthenticatedPublic
 public:
        AuthenticatedPublic ()
                : message_id (make_uuid ())
+                 /* XXX: hack for Dolby to see if there must be a not-empty annotation text */
+               , annotation_text ("none")
                , issue_date (LocalTime().as_string ())
        {}
-       
-       AuthenticatedPublic (shared_ptr<const cxml::Node> node)
-               : message_id (node->string_child ("MessageId").substr (9))
-               , annotation_text (node->string_child ("AnnotationText"))
+
+       explicit AuthenticatedPublic (shared_ptr<const cxml::Node> node)
+               : message_id (remove_urn_uuid (node->string_child ("MessageId")))
+               , annotation_text (node->optional_string_child ("AnnotationText"))
                , issue_date (node->string_child ("IssueDate"))
                , signer (node->node_child ("Signer"))
                , required_extensions (node->node_child ("RequiredExtensions"))
@@ -419,10 +455,12 @@ public:
        void as_xml (xmlpp::Element* node, map<string, xmlpp::Attribute *>& references) const
        {
                references["ID_AuthenticatedPublic"] = node->set_attribute ("Id", "ID_AuthenticatedPublic");
-               
+
                node->add_child("MessageId")->add_child_text ("urn:uuid:" + message_id);
                node->add_child("MessageType")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#kdm-key-type");
-               node->add_child("AnnotationText")->add_child_text (annotation_text);
+               if (annotation_text) {
+                       node->add_child("AnnotationText")->add_child_text (annotation_text.get ());
+               }
                node->add_child("IssueDate")->add_child_text (issue_date);
 
                signer.as_xml (node->add_child ("Signer"));
@@ -432,7 +470,7 @@ public:
        }
 
        string message_id;
-       string annotation_text;
+       optional<string> annotation_text;
        string issue_date;
        Signer signer;
        RequiredExtensions required_extensions;
@@ -448,13 +486,13 @@ public:
        {
 
        }
-       
-       EncryptedKDMData (shared_ptr<const cxml::Node> node)
+
+       explicit EncryptedKDMData (shared_ptr<const cxml::Node> node)
                : authenticated_public (node->node_child ("AuthenticatedPublic"))
                , authenticated_private (node->node_child ("AuthenticatedPrivate"))
                , signature (node->node_child ("Signature"))
        {
-               
+
        }
 
        shared_ptr<xmlpp::Document> as_xml () const
@@ -483,18 +521,20 @@ public:
 }
 }
 
-EncryptedKDM::EncryptedKDM (boost::filesystem::path file)
-       : _data (new data::EncryptedKDMData (shared_ptr<cxml::Node> (new cxml::Document ("DCinemaSecurityMessage", file))))
+EncryptedKDM::EncryptedKDM (string s)
 {
-       
+       shared_ptr<cxml::Document> doc (new cxml::Document ("DCinemaSecurityMessage"));
+       doc->read_string (s);
+       _data = new data::EncryptedKDMData (doc);
 }
 
 EncryptedKDM::EncryptedKDM (
-       shared_ptr<const Signer> signer,
-       shared_ptr<const Certificate> recipient,
-       string device_list_description,
+       shared_ptr<const CertificateChain> signer,
+       Certificate recipient,
+       vector<Certificate> trusted_devices,
        string cpl_id,
        string content_title_text,
+       optional<string> annotation_text,
        LocalTime not_valid_before,
        LocalTime not_valid_after,
        Formulation formulation,
@@ -504,36 +544,48 @@ EncryptedKDM::EncryptedKDM (
        : _data (new data::EncryptedKDMData)
 {
        /* Fill our XML-ish description in with the juicy bits that the caller has given */
-       
+
        data::AuthenticatedPublic& aup = _data->authenticated_public;
-       aup.signer.x509_issuer_name = signer->certificates().leaf()->issuer ();
-       aup.signer.x509_serial_number = signer->certificates().leaf()->serial ();
+       aup.signer.x509_issuer_name = signer->leaf().issuer ();
+       aup.signer.x509_serial_number = signer->leaf().serial ();
+       aup.annotation_text = annotation_text;
 
        data::KDMRequiredExtensions& kre = _data->authenticated_public.required_extensions.kdm_required_extensions;
-       kre.recipient.x509_issuer_serial.x509_issuer_name = recipient->issuer ();
-       kre.recipient.x509_issuer_serial.x509_serial_number = recipient->serial ();
-       kre.recipient.x509_subject_name = recipient->subject ();
-       kre.authorized_device_info.device_list_description = device_list_description;
+       kre.recipient.x509_issuer_serial.x509_issuer_name = recipient.issuer ();
+       kre.recipient.x509_issuer_serial.x509_serial_number = recipient.serial ();
+       kre.recipient.x509_subject_name = recipient.subject ();
        kre.composition_playlist_id = cpl_id;
        if (formulation == DCI_ANY || formulation == DCI_SPECIFIC) {
-               kre.content_authenticator = signer->certificates().leaf()->thumbprint ();
+               kre.content_authenticator = signer->leaf().thumbprint ();
        }
        kre.content_title_text = content_title_text;
        kre.not_valid_before = not_valid_before;
        kre.not_valid_after = not_valid_after;
-       kre.authorized_device_info.device_list_identifier = "urn:uuid:" + make_uuid ();
-       string n = recipient->common_name ();
-       if (n.find (".") != string::npos) {
-               n = n.substr (n.find (".") + 1);
-       }
-       kre.authorized_device_info.device_list_description = n;
 
-       if (formulation == MODIFIED_TRANSITIONAL_1 || formulation == DCI_ANY) {
-               /* Use the "assume trust" thumbprint */
-               kre.authorized_device_info.certificate_thumbprint = "2jmj7l5rSw0yVb/vlWAYkK/YBwk=";
-       } else if (formulation == DCI_SPECIFIC) {
-               /* Use the recipient thumbprint */
-               kre.authorized_device_info.certificate_thumbprint = recipient->thumbprint ();
+       if (formulation != MODIFIED_TRANSITIONAL_TEST) {
+               kre.authorized_device_info = data::AuthorizedDeviceInfo ();
+               kre.authorized_device_info->device_list_identifier = make_uuid ();
+               string n = recipient.subject_common_name ();
+               if (n.find (".") != string::npos) {
+                       n = n.substr (n.find (".") + 1);
+               }
+               kre.authorized_device_info->device_list_description = n;
+
+               if (formulation == MODIFIED_TRANSITIONAL_1 || formulation == DCI_ANY) {
+                       /* Use the "assume trust" thumbprint */
+                       kre.authorized_device_info->certificate_thumbprints.push_back ("2jmj7l5rSw0yVb/vlWAYkK/YBwk=");
+               } else if (formulation == DCI_SPECIFIC) {
+                       /* As I read the standard we should use the recipient
+                          /and/ other trusted device thumbprints here.  MJD
+                          reports that this doesn't work with his setup;
+                          a working KDM does not include the recipient's
+                          thumbprint (recipient.thumbprint()).
+                          Waimea uses only the trusted devices here, too.
+                       */
+                       BOOST_FOREACH (Certificate const & i, trusted_devices) {
+                               kre.authorized_device_info->certificate_thumbprints.push_back (i.thumbprint ());
+                       }
+               }
        }
 
        for (list<pair<string, string> >::const_iterator i = key_ids.begin(); i != key_ids.end(); ++i) {
@@ -587,15 +639,10 @@ EncryptedKDM::as_xml (boost::filesystem::path path) const
        fwrite (x.c_str(), 1, x.length(), f);
        fclose (f);
 }
-       
+
 string
 EncryptedKDM::as_xml () const
 {
-       xmlpp::Document document;
-       xmlpp::Element* root = document.create_root_node ("DCinemaSecurityMessage", "http://www.smpte-ra.org/schemas/430-3/2006/ETM");
-       root->set_namespace_declaration ("http://www.w3.org/2000/09/xmldsig#", "ds");
-       root->set_namespace_declaration ("http://www.w3.org/2001/04/xmlenc#", "enc");
-
        return _data->as_xml()->write_to_string ("UTF-8");
 }
 
@@ -604,3 +651,46 @@ EncryptedKDM::keys () const
 {
        return _data->authenticated_private.encrypted_key;
 }
+
+optional<string>
+EncryptedKDM::annotation_text () const
+{
+       return _data->authenticated_public.annotation_text;
+}
+
+string
+EncryptedKDM::content_title_text () const
+{
+       return _data->authenticated_public.required_extensions.kdm_required_extensions.content_title_text;
+}
+
+string
+EncryptedKDM::cpl_id () const
+{
+       return _data->authenticated_public.required_extensions.kdm_required_extensions.composition_playlist_id;
+}
+
+string
+EncryptedKDM::issue_date () const
+{
+       return _data->authenticated_public.issue_date;
+}
+
+LocalTime
+EncryptedKDM::not_valid_before () const
+{
+       return _data->authenticated_public.required_extensions.kdm_required_extensions.not_valid_before;
+}
+
+LocalTime
+EncryptedKDM::not_valid_after () const
+{
+       return _data->authenticated_public.required_extensions.kdm_required_extensions.not_valid_after;
+}
+
+bool
+dcp::operator== (EncryptedKDM const & a, EncryptedKDM const & b)
+{
+       /* Not exactly efficient... */
+       return a.as_xml() == b.as_xml();
+}