src/encrypted_kdm.cc

   1 /*
   2     Copyright (C) 2013-2014 Carl Hetherington <cth@carlh.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17
  18 */
  19
  20 #include "encrypted_kdm.h"
  21 #include "util.h"
  22 #include "signer.h"
  23 #include <libcxml/cxml.h>
  24 #include <libxml++/document.h>
  25 #include <libxml++/nodes/element.h>
  26 #include <libxml/parser.h>
  27 #include <boost/date_time/posix_time/posix_time.hpp>
  28
  29 using std::list;
  30 using std::string;
  31 using std::map;
  32 using std::pair;
  33 using boost::shared_ptr;
  34 using namespace dcp;
  35
  36 namespace dcp {
  37
  38 /** Namespace for classes used to hold our data; they are internal to this .cc file */
  39 namespace data {
  40
  41 class Signer
  42 {
  43 public:
  44         Signer () {}
  45
  46         Signer (shared_ptr<const cxml::Node> node)
  47                 : x509_issuer_name (node->string_child ("X509IssuerName"))
  48                 , x509_serial_number (node->string_child ("X509SerialNumber"))
  49         {
  50
  51         }
  52
  53         void as_xml (xmlpp::Element* node) const
  54         {
  55                 node->add_child("X509IssuerName", "ds")->add_child_text (x509_issuer_name);
  56                 node->add_child("X509SerialNumber", "ds")->add_child_text (x509_serial_number);
  57         }
  58
  59         string x509_issuer_name;
  60         string x509_serial_number;
  61 };
  62
  63 class X509Data
  64 {
  65 public:
  66         X509Data () {}
  67
  68         X509Data (boost::shared_ptr<const cxml::Node> node)
  69                 : x509_issuer_serial (Signer (node->node_child ("X509IssuerSerial")))
  70                 , x509_certificate (node->string_child ("X509Certificate"))
  71         {
  72                 node->done ();
  73         }
  74
  75         void as_xml (xmlpp::Element* node) const
  76         {
  77                 x509_issuer_serial.as_xml (node->add_child ("X509IssuerSerial", "ds"));
  78                 node->add_child("X509Certificate", "ds")->add_child_text (x509_certificate);
  79         }
  80
  81         Signer x509_issuer_serial;
  82         std::string x509_certificate;
  83 };
  84
  85 class Reference
  86 {
  87 public:
  88         Reference () {}
  89
  90         Reference (string u)
  91                 : uri (u)
  92         {}
  93
  94         Reference (shared_ptr<const cxml::Node> node)
  95                 : uri (node->string_attribute ("URI"))
  96                 , digest_value (node->string_child ("DigestValue"))
  97         {
  98
  99         }
 100
 101         void as_xml (xmlpp::Element* node) const
 102         {
 103                 node->set_attribute ("URI", uri);
 104                 node->add_child("DigestMethod", "ds")->set_attribute ("Algorithm", "http://www.w3.org/2001/04/xmlenc#sha256");
 105                 node->add_child("DigestValue", "ds")->add_child_text (digest_value);
 106         }
 107
 108         string uri;
 109         string digest_value;
 110 };
 111
 112 class SignedInfo
 113 {
 114 public:
 115         SignedInfo ()
 116                 : authenticated_public ("#ID_AuthenticatedPublic")
 117                 , authenticated_private ("#ID_AuthenticatedPrivate")
 118         {}
 119
 120         SignedInfo (shared_ptr<const cxml::Node> node)
 121         {
 122                 list<shared_ptr<cxml::Node> > references = node->node_children ("Reference");
 123                 for (list<shared_ptr<cxml::Node> >::const_iterator i = references.begin(); i != references.end(); ++i) {
 124                         if ((*i)->string_attribute ("URI") == "#ID_AuthenticatedPublic") {
 125                                 authenticated_public = Reference (*i);
 126                         } else if ((*i)->string_attribute ("URI") == "#ID_AuthenticatedPrivate") {
 127                                 authenticated_private = Reference (*i);
 128                         }
 129
 130                         /* XXX: do something if we don't recognise the node */
 131                 }
 132         }
 133
 134         void as_xml (xmlpp::Element* node) const
 135         {
 136                 node->add_child ("CanonicalizationMethod", "ds")->set_attribute (
 137                         "Algorithm", "http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments"
 138                         );
 139
 140                 node->add_child ("SignatureMethod", "ds")->set_attribute (
 141                         "Algorithm", "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"
 142                         );
 143
 144                 authenticated_public.as_xml (node->add_child ("Reference", "ds"));
 145                 authenticated_private.as_xml (node->add_child ("Reference", "ds"));
 146         }
 147
 148 private:
 149         Reference authenticated_public;
 150         Reference authenticated_private;
 151 };
 152
 153 class Signature
 154 {
 155 public:
 156         Signature () {}
 157
 158         Signature (shared_ptr<const cxml::Node> node)
 159                 : signed_info (node->node_child ("SignedInfo"))
 160                 , signature_value (node->string_child ("SignatureValue"))
 161         {
 162                 list<shared_ptr<cxml::Node> > x509_data_nodes = node->node_child("KeyInfo")->node_children ("X509Data");
 163                 for (list<shared_ptr<cxml::Node> >::const_iterator i = x509_data_nodes.begin(); i != x509_data_nodes.end(); ++i) {
 164                         x509_data.push_back (X509Data (*i));
 165                 }
 166         }
 167
 168         void as_xml (xmlpp::Node* node) const
 169         {
 170                 signed_info.as_xml (node->add_child ("SignedInfo", "ds"));
 171                 node->add_child("SignatureValue", "ds")->add_child_text (signature_value);
 172
 173                 xmlpp::Element* key_info_node = node->add_child ("KeyInfo", "ds");
 174                 for (std::list<X509Data>::const_iterator i = x509_data.begin(); i != x509_data.end(); ++i) {
 175                         i->as_xml (key_info_node->add_child ("X509Data", "ds"));
 176                 }
 177         }
 178
 179         SignedInfo signed_info;
 180         string signature_value;
 181         list<X509Data> x509_data;
 182 };
 183
 184 class AuthenticatedPrivate
 185 {
 186 public:
 187         AuthenticatedPrivate () {}
 188
 189         AuthenticatedPrivate (shared_ptr<const cxml::Node> node)
 190         {
 191                 list<shared_ptr<cxml::Node> > encrypted_key_nodes = node->node_children ("EncryptedKey");
 192                 for (list<shared_ptr<cxml::Node> >::const_iterator i = encrypted_key_nodes.begin(); i != encrypted_key_nodes.end(); ++i) {
 193                         encrypted_key.push_back ((*i)->node_child("CipherData")->string_child ("CipherValue"));
 194                 }
 195         }
 196
 197         void as_xml (xmlpp::Element* node, map<string, xmlpp::Attribute *>& references) const
 198         {
 199                 references["ID_AuthenticatedPrivate"] = node->set_attribute ("Id", "ID_AuthenticatedPrivate");
 200
 201                 for (list<string>::const_iterator i = encrypted_key.begin(); i != encrypted_key.end(); ++i) {
 202                         xmlpp::Element* encrypted_key = node->add_child ("EncryptedKey", "enc");
 203                         xmlpp::Element* encryption_method = encrypted_key->add_child ("EncryptionMethod", "enc");
 204                         encryption_method->set_attribute ("Algorithm", "http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p");
 205                         xmlpp::Element* digest_method = encryption_method->add_child ("DigestMethod", "ds");
 206                         digest_method->set_attribute ("Algorithm", "http://www.w3.org/2000/09/xmldsig#sha1");
 207                         xmlpp::Element* cipher_data = encrypted_key->add_child ("CipherData", "enc");
 208                         cipher_data->add_child("CipherValue", "enc")->add_child_text (*i);
 209                 }
 210         }
 211
 212         list<string> encrypted_key;
 213 };
 214
 215 class TypedKeyId
 216 {
 217 public:
 218         TypedKeyId () {}
 219
 220         TypedKeyId (shared_ptr<const cxml::Node> node)
 221                 : key_type (node->string_child ("KeyType"))
 222                 , key_id (node->string_child ("KeyId").substr (9))
 223         {
 224
 225         }
 226
 227         TypedKeyId (string type, string id)
 228                 : key_type (type)
 229                 , key_id (id)
 230         {}
 231
 232         void as_xml (xmlpp::Element* node) const
 233         {
 234                 node->add_child("KeyType")->add_child_text (key_type);
 235                 node->add_child("KeyId")->add_child_text ("urn:uuid:" + key_id);
 236         }
 237
 238         string key_type;
 239         string key_id;
 240 };
 241
 242 class KeyIdList
 243 {
 244 public:
 245         KeyIdList () {}
 246
 247         KeyIdList (shared_ptr<const cxml::Node> node)
 248         {
 249                 list<shared_ptr<cxml::Node> > typed_key_id_nodes = node->node_children ("TypedKeyId");
 250                 for (list<shared_ptr<cxml::Node> >::const_iterator i = typed_key_id_nodes.begin(); i != typed_key_id_nodes.end(); ++i) {
 251                         typed_key_id.push_back (TypedKeyId (*i));
 252                 }
 253         }
 254
 255         void as_xml (xmlpp::Element* node) const
 256         {
 257                 for (list<TypedKeyId>::const_iterator i = typed_key_id.begin(); i != typed_key_id.end(); ++i) {
 258                         i->as_xml (node->add_child("TypedKeyId"));
 259                 }
 260         }
 261
 262         list<TypedKeyId> typed_key_id;
 263 };
 264
 265 class AuthorizedDeviceInfo
 266 {
 267 public:
 268         AuthorizedDeviceInfo () {}
 269
 270         AuthorizedDeviceInfo (shared_ptr<const cxml::Node> node)
 271                 : device_list_identifier (node->string_child ("DeviceListIdentifier").substr (9))
 272                 , device_list_description (node->string_child ("DeviceListDescription"))
 273                 , certificate_thumbprint (node->node_child("DeviceList")->string_child ("CertificateThumbprint"))
 274         {
 275
 276         }
 277
 278         void as_xml (xmlpp::Element* node) const
 279         {
 280                 node->add_child ("DeviceListIdentifier")->add_child_text ("urn:uuid:" + device_list_identifier);
 281                 node->add_child ("DeviceListDescription")->add_child_text (device_list_description);
 282                 xmlpp::Element* device_list = node->add_child ("DeviceList");
 283                 device_list->add_child("CertificateThumbprint")->add_child_text (certificate_thumbprint);
 284         }
 285
 286         /** DeviceListIdentifier without the urn:uuid: prefix */
 287         string device_list_identifier;
 288         string device_list_description;
 289         string certificate_thumbprint;
 290 };
 291
 292 class X509IssuerSerial
 293 {
 294 public:
 295         X509IssuerSerial () {}
 296
 297         X509IssuerSerial (shared_ptr<const cxml::Node> node)
 298                 : x509_issuer_name (node->string_child ("X509IssuerName"))
 299                 , x509_serial_number (node->string_child ("X509SerialNumber"))
 300         {
 301
 302         }
 303
 304         void as_xml (xmlpp::Element* node) const
 305         {
 306                 node->add_child("X509IssuerName", "ds")->add_child_text (x509_issuer_name);
 307                 node->add_child("X509SerialNumber", "ds")->add_child_text (x509_serial_number);
 308         }
 309
 310         string x509_issuer_name;
 311         string x509_serial_number;
 312 };
 313
 314 class Recipient
 315 {
 316 public:
 317         Recipient () {}
 318
 319         Recipient (shared_ptr<const cxml::Node> node)
 320                 : x509_issuer_serial (node->node_child ("X509IssuerSerial"))
 321                 , x509_subject_name (node->string_child ("X509SubjectName"))
 322         {
 323
 324         }
 325
 326         void as_xml (xmlpp::Element* node) const
 327         {
 328                 x509_issuer_serial.as_xml (node->add_child ("X509IssuerSerial"));
 329                 node->add_child("X509SubjectName")->add_child_text (x509_subject_name);
 330         }
 331
 332         X509IssuerSerial x509_issuer_serial;
 333         string x509_subject_name;
 334 };
 335
 336 class KDMRequiredExtensions
 337 {
 338 public:
 339         KDMRequiredExtensions () {}
 340
 341         KDMRequiredExtensions (shared_ptr<const cxml::Node> node)
 342                 : recipient (node->node_child ("Recipient"))
 343                 , composition_playlist_id (node->string_child ("CompositionPlaylistId").substr (9))
 344                 , content_title_text (node->string_child ("ContentTitleText"))
 345                 , not_valid_before (node->string_child ("ContentKeysNotValidBefore"))
 346                 , not_valid_after (node->string_child ("ContentKeysNotValidAfter"))
 347                 , authorized_device_info (node->node_child ("AuthorizedDeviceInfo"))
 348                 , key_id_list (node->node_child ("KeyIdList"))
 349         {
 350
 351         }
 352
 353         void as_xml (xmlpp::Element* node) const
 354         {
 355                 node->set_attribute ("xmlns", "http://www.smpte-ra.org/schemas/430-1/2006/KDM");
 356
 357                 recipient.as_xml (node->add_child ("Recipient"));
 358                 node->add_child("CompositionPlaylistId")->add_child_text ("urn:uuid:" + composition_playlist_id);
 359                 if (content_authenticator) {
 360                         node->add_child("ContentAuthenticator")->add_child_text (content_authenticator.get ());
 361                 }
 362                 node->add_child("ContentTitleText")->add_child_text (content_title_text);
 363                 node->add_child("ContentKeysNotValidBefore")->add_child_text (not_valid_before.as_string ());
 364                 node->add_child("ContentKeysNotValidAfter")->add_child_text (not_valid_after.as_string ());
 365                 authorized_device_info.as_xml (node->add_child ("AuthorizedDeviceInfo"));
 366                 key_id_list.as_xml (node->add_child ("KeyIdList"));
 367
 368                 xmlpp::Element* forensic_mark_flag_list = node->add_child ("ForensicMarkFlagList");
 369                 forensic_mark_flag_list->add_child("ForensicMarkFlag")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#mrkflg-picture-disable");
 370                 forensic_mark_flag_list->add_child("ForensicMarkFlag")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#mrkflg-audio-disable");
 371         }
 372
 373         Recipient recipient;
 374         string composition_playlist_id;
 375         boost::optional<string> content_authenticator;
 376         string content_title_text;
 377         LocalTime not_valid_before;
 378         LocalTime not_valid_after;
 379         AuthorizedDeviceInfo authorized_device_info;
 380         KeyIdList key_id_list;
 381 };
 382
 383 class RequiredExtensions
 384 {
 385 public:
 386         RequiredExtensions () {}
 387
 388         RequiredExtensions (shared_ptr<const cxml::Node> node)
 389                 : kdm_required_extensions (node->node_child ("KDMRequiredExtensions"))
 390         {
 391
 392         }
 393
 394         void as_xml (xmlpp::Element* node) const
 395         {
 396                 kdm_required_extensions.as_xml (node->add_child ("KDMRequiredExtensions"));
 397         }
 398
 399         KDMRequiredExtensions kdm_required_extensions;
 400 };
 401
 402 class AuthenticatedPublic
 403 {
 404 public:
 405         AuthenticatedPublic ()
 406                 : message_id (make_uuid ())
 407                 , issue_date (LocalTime().as_string ())
 408         {}
 409
 410         AuthenticatedPublic (shared_ptr<const cxml::Node> node)
 411                 : message_id (node->string_child ("MessageId").substr (9))
 412                 , annotation_text (node->string_child ("AnnotationText"))
 413                 , issue_date (node->string_child ("IssueDate"))
 414                 , signer (node->node_child ("Signer"))
 415                 , required_extensions (node->node_child ("RequiredExtensions"))
 416         {
 417
 418         }
 419
 420         void as_xml (xmlpp::Element* node, map<string, xmlpp::Attribute *>& references) const
 421         {
 422                 references["ID_AuthenticatedPublic"] = node->set_attribute ("Id", "ID_AuthenticatedPublic");
 423
 424                 node->add_child("MessageId")->add_child_text ("urn:uuid:" + message_id);
 425                 node->add_child("MessageType")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#kdm-key-type");
 426                 node->add_child("AnnotationText")->add_child_text (annotation_text);
 427                 node->add_child("IssueDate")->add_child_text (issue_date);
 428
 429                 signer.as_xml (node->add_child ("Signer"));
 430                 required_extensions.as_xml (node->add_child ("RequiredExtensions"));
 431
 432                 node->add_child ("NonCriticalExtensions");
 433         }
 434
 435         string message_id;
 436         string annotation_text;
 437         string issue_date;
 438         Signer signer;
 439         RequiredExtensions required_extensions;
 440 };
 441
 442 /** Class to describe our data.  We use a class hierarchy as it's a bit nicer
 443  *  for XML data than a flat description.
 444  */
 445 class EncryptedKDMData
 446 {
 447 public:
 448         EncryptedKDMData ()
 449         {
 450
 451         }
 452
 453         EncryptedKDMData (shared_ptr<const cxml::Node> node)
 454                 : authenticated_public (node->node_child ("AuthenticatedPublic"))
 455                 , authenticated_private (node->node_child ("AuthenticatedPrivate"))
 456                 , signature (node->node_child ("Signature"))
 457         {
 458
 459         }
 460
 461         shared_ptr<xmlpp::Document> as_xml () const
 462         {
 463                 shared_ptr<xmlpp::Document> document (new xmlpp::Document ());
 464                 xmlpp::Element* root = document->create_root_node ("DCinemaSecurityMessage", "http://www.smpte-ra.org/schemas/430-3/2006/ETM");
 465                 root->set_namespace_declaration ("http://www.w3.org/2000/09/xmldsig#", "ds");
 466                 root->set_namespace_declaration ("http://www.w3.org/2001/04/xmlenc#", "enc");
 467                 map<string, xmlpp::Attribute *> references;
 468                 authenticated_public.as_xml (root->add_child ("AuthenticatedPublic"), references);
 469                 authenticated_private.as_xml (root->add_child ("AuthenticatedPrivate"), references);
 470                 signature.as_xml (root->add_child ("Signature", "ds"));
 471
 472                 for (map<string, xmlpp::Attribute*>::const_iterator i = references.begin(); i != references.end(); ++i) {
 473                         xmlAddID (0, document->cobj(), (const xmlChar *) i->first.c_str(), i->second->cobj ());
 474                 }
 475
 476                 return document;
 477         }
 478
 479         AuthenticatedPublic authenticated_public;
 480         AuthenticatedPrivate authenticated_private;
 481         Signature signature;
 482 };
 483
 484 }
 485 }
 486
 487 EncryptedKDM::EncryptedKDM (boost::filesystem::path file)
 488         : _data (new data::EncryptedKDMData (shared_ptr<cxml::Node> (new cxml::Document ("DCinemaSecurityMessage", file))))
 489 {
 490
 491 }
 492
 493 EncryptedKDM::EncryptedKDM (
 494         shared_ptr<const Signer> signer,
 495         shared_ptr<const Certificate> recipient,
 496         string device_list_description,
 497         string cpl_id,
 498         string content_title_text,
 499         LocalTime not_valid_before,
 500         LocalTime not_valid_after,
 501         Formulation formulation,
 502         list<pair<string, string> > key_ids,
 503         list<string> keys
 504         )
 505         : _data (new data::EncryptedKDMData)
 506 {
 507         /* Fill our XML-ish description in with the juicy bits that the caller has given */
 508
 509         data::AuthenticatedPublic& aup = _data->authenticated_public;
 510         aup.signer.x509_issuer_name = signer->certificates().leaf()->issuer ();
 511         aup.signer.x509_serial_number = signer->certificates().leaf()->serial ();
 512
 513         data::KDMRequiredExtensions& kre = _data->authenticated_public.required_extensions.kdm_required_extensions;
 514         kre.recipient.x509_issuer_serial.x509_issuer_name = recipient->issuer ();
 515         kre.recipient.x509_issuer_serial.x509_serial_number = recipient->serial ();
 516         kre.recipient.x509_subject_name = recipient->subject ();
 517         kre.authorized_device_info.device_list_description = device_list_description;
 518         kre.composition_playlist_id = cpl_id;
 519         if (formulation == DCI_ANY || formulation == DCI_SPECIFIC) {
 520                 kre.content_authenticator = signer->certificates().leaf()->thumbprint ();
 521         }
 522         kre.content_title_text = content_title_text;
 523         kre.not_valid_before = not_valid_before;
 524         kre.not_valid_after = not_valid_after;
 525         kre.authorized_device_info.device_list_identifier = make_uuid ();
 526         string n = recipient->common_name ();
 527         if (n.find (".") != string::npos) {
 528                 n = n.substr (n.find (".") + 1);
 529         }
 530         kre.authorized_device_info.device_list_description = n;
 531
 532         if (formulation == MODIFIED_TRANSITIONAL_1 || formulation == DCI_ANY) {
 533                 /* Use the "assume trust" thumbprint */
 534                 kre.authorized_device_info.certificate_thumbprint = "2jmj7l5rSw0yVb/vlWAYkK/YBwk=";
 535         } else if (formulation == DCI_SPECIFIC) {
 536                 /* Use the recipient thumbprint */
 537                 kre.authorized_device_info.certificate_thumbprint = recipient->thumbprint ();
 538         }
 539
 540         for (list<pair<string, string> >::const_iterator i = key_ids.begin(); i != key_ids.end(); ++i) {
 541                 kre.key_id_list.typed_key_id.push_back (data::TypedKeyId (i->first, i->second));
 542         }
 543
 544         _data->authenticated_private.encrypted_key = keys;
 545
 546         /* Read the XML so far and sign it */
 547         shared_ptr<xmlpp::Document> doc = _data->as_xml ();
 548         xmlpp::Node::NodeList children = doc->get_root_node()->get_children ();
 549         for (xmlpp::Node::NodeList::const_iterator i = children.begin(); i != children.end(); ++i) {
 550                 if ((*i)->get_name() == "Signature") {
 551                         signer->add_signature_value (*i, "ds");
 552                 }
 553         }
 554
 555         /* Read the bits that add_signature_value did back into our variables */
 556         shared_ptr<cxml::Node> signed_doc (new cxml::Node (doc->get_root_node ()));
 557         _data->signature = data::Signature (signed_doc->node_child ("Signature"));
 558 }
 559
 560 EncryptedKDM::EncryptedKDM (EncryptedKDM const & other)
 561         : _data (new data::EncryptedKDMData (*other._data))
 562 {
 563
 564 }
 565
 566 EncryptedKDM &
 567 EncryptedKDM::operator= (EncryptedKDM const & other)
 568 {
 569         if (this == &other) {
 570                 return *this;
 571         }
 572
 573         delete _data;
 574         _data = new data::EncryptedKDMData (*other._data);
 575         return *this;
 576 }
 577
 578 EncryptedKDM::~EncryptedKDM ()
 579 {
 580         delete _data;
 581 }
 582
 583 void
 584 EncryptedKDM::as_xml (boost::filesystem::path path) const
 585 {
 586         FILE* f = fopen_boost (path, "w");
 587         string const x = as_xml ();
 588         fwrite (x.c_str(), 1, x.length(), f);
 589         fclose (f);
 590 }
 591
 592 string
 593 EncryptedKDM::as_xml () const
 594 {
 595         xmlpp::Document document;
 596         xmlpp::Element* root = document.create_root_node ("DCinemaSecurityMessage", "http://www.smpte-ra.org/schemas/430-3/2006/ETM");
 597         root->set_namespace_declaration ("http://www.w3.org/2000/09/xmldsig#", "ds");
 598         root->set_namespace_declaration ("http://www.w3.org/2001/04/xmlenc#", "enc");
 599
 600         return _data->as_xml()->write_to_string ("UTF-8");
 601 }
 602
 603 list<string>
 604 EncryptedKDM::keys () const
 605 {
 606         return _data->authenticated_private.encrypted_key;
 607 }