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         string device_list_identifier;
 287         string device_list_description;
 288         string certificate_thumbprint;
 289 };
 290
 291 class X509IssuerSerial
 292 {
 293 public:
 294         X509IssuerSerial () {}
 295
 296         X509IssuerSerial (shared_ptr<const cxml::Node> node)
 297                 : x509_issuer_name (node->string_child ("X509IssuerName"))
 298                 , x509_serial_number (node->string_child ("X509SerialNumber"))
 299         {
 300
 301         }
 302
 303         void as_xml (xmlpp::Element* node) const
 304         {
 305                 node->add_child("X509IssuerName", "ds")->add_child_text (x509_issuer_name);
 306                 node->add_child("X509SerialNumber", "ds")->add_child_text (x509_serial_number);
 307         }
 308
 309         string x509_issuer_name;
 310         string x509_serial_number;
 311 };
 312
 313 class Recipient
 314 {
 315 public:
 316         Recipient () {}
 317
 318         Recipient (shared_ptr<const cxml::Node> node)
 319                 : x509_issuer_serial (node->node_child ("X509IssuerSerial"))
 320                 , x509_subject_name (node->string_child ("X509SubjectName"))
 321         {
 322
 323         }
 324
 325         void as_xml (xmlpp::Element* node) const
 326         {
 327                 x509_issuer_serial.as_xml (node->add_child ("X509IssuerSerial"));
 328                 node->add_child("X509SubjectName")->add_child_text (x509_subject_name);
 329         }
 330
 331         X509IssuerSerial x509_issuer_serial;
 332         string x509_subject_name;
 333 };
 334
 335 class KDMRequiredExtensions
 336 {
 337 public:
 338         KDMRequiredExtensions () {}
 339
 340         KDMRequiredExtensions (shared_ptr<const cxml::Node> node)
 341                 : recipient (node->node_child ("Recipient"))
 342                 , composition_playlist_id (node->string_child ("CompositionPlaylistId").substr (9))
 343                 , content_title_text (node->string_child ("ContentTitleText"))
 344                 , not_valid_before (node->string_child ("ContentKeysNotValidBefore"))
 345                 , not_valid_after (node->string_child ("ContentKeysNotValidAfter"))
 346                 , authorized_device_info (node->node_child ("AuthorizedDeviceInfo"))
 347                 , key_id_list (node->node_child ("KeyIdList"))
 348         {
 349
 350         }
 351
 352         void as_xml (xmlpp::Element* node) const
 353         {
 354                 node->set_attribute ("xmlns", "http://www.smpte-ra.org/schemas/430-1/2006/KDM");
 355
 356                 recipient.as_xml (node->add_child ("Recipient"));
 357                 node->add_child("CompositionPlaylistId")->add_child_text ("urn:uuid:" + composition_playlist_id);
 358                 if (content_authenticator) {
 359                         node->add_child("ContentAuthenticator")->add_child_text (content_authenticator.get ());
 360                 }
 361                 node->add_child("ContentTitleText")->add_child_text (content_title_text);
 362                 node->add_child("ContentKeysNotValidBefore")->add_child_text (not_valid_before.as_string ());
 363                 node->add_child("ContentKeysNotValidAfter")->add_child_text (not_valid_after.as_string ());
 364                 authorized_device_info.as_xml (node->add_child ("AuthorizedDeviceInfo"));
 365                 key_id_list.as_xml (node->add_child ("KeyIdList"));
 366
 367                 xmlpp::Element* forensic_mark_flag_list = node->add_child ("ForensicMarkFlagList");
 368                 forensic_mark_flag_list->add_child("ForensicMarkFlag")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#mrkflg-picture-disable");
 369                 forensic_mark_flag_list->add_child("ForensicMarkFlag")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#mrkflg-audio-disable");
 370         }
 371
 372         Recipient recipient;
 373         string composition_playlist_id;
 374         boost::optional<string> content_authenticator;
 375         string content_title_text;
 376         LocalTime not_valid_before;
 377         LocalTime not_valid_after;
 378         AuthorizedDeviceInfo authorized_device_info;
 379         KeyIdList key_id_list;
 380 };
 381
 382 class RequiredExtensions
 383 {
 384 public:
 385         RequiredExtensions () {}
 386
 387         RequiredExtensions (shared_ptr<const cxml::Node> node)
 388                 : kdm_required_extensions (node->node_child ("KDMRequiredExtensions"))
 389         {
 390
 391         }
 392
 393         void as_xml (xmlpp::Element* node) const
 394         {
 395                 kdm_required_extensions.as_xml (node->add_child ("KDMRequiredExtensions"));
 396         }
 397
 398         KDMRequiredExtensions kdm_required_extensions;
 399 };
 400
 401 class AuthenticatedPublic
 402 {
 403 public:
 404         AuthenticatedPublic ()
 405                 : message_id (make_uuid ())
 406                 , issue_date (LocalTime().as_string ())
 407         {}
 408
 409         AuthenticatedPublic (shared_ptr<const cxml::Node> node)
 410                 : message_id (node->string_child ("MessageId").substr (9))
 411                 , annotation_text (node->string_child ("AnnotationText"))
 412                 , issue_date (node->string_child ("IssueDate"))
 413                 , signer (node->node_child ("Signer"))
 414                 , required_extensions (node->node_child ("RequiredExtensions"))
 415         {
 416
 417         }
 418
 419         void as_xml (xmlpp::Element* node, map<string, xmlpp::Attribute *>& references) const
 420         {
 421                 references["ID_AuthenticatedPublic"] = node->set_attribute ("Id", "ID_AuthenticatedPublic");
 422
 423                 node->add_child("MessageId")->add_child_text ("urn:uuid:" + message_id);
 424                 node->add_child("MessageType")->add_child_text ("http://www.smpte-ra.org/430-1/2006/KDM#kdm-key-type");
 425                 node->add_child("AnnotationText")->add_child_text (annotation_text);
 426                 node->add_child("IssueDate")->add_child_text (issue_date);
 427
 428                 signer.as_xml (node->add_child ("Signer"));
 429                 required_extensions.as_xml (node->add_child ("RequiredExtensions"));
 430
 431                 node->add_child ("NonCriticalExtensions");
 432         }
 433
 434         string message_id;
 435         string annotation_text;
 436         string issue_date;
 437         Signer signer;
 438         RequiredExtensions required_extensions;
 439 };
 440
 441 /** Class to describe our data.  We use a class hierarchy as it's a bit nicer
 442  *  for XML data than a flat description.
 443  */
 444 class EncryptedKDMData
 445 {
 446 public:
 447         EncryptedKDMData ()
 448         {
 449
 450         }
 451
 452         EncryptedKDMData (shared_ptr<const cxml::Node> node)
 453                 : authenticated_public (node->node_child ("AuthenticatedPublic"))
 454                 , authenticated_private (node->node_child ("AuthenticatedPrivate"))
 455                 , signature (node->node_child ("Signature"))
 456         {
 457
 458         }
 459
 460         shared_ptr<xmlpp::Document> as_xml () const
 461         {
 462                 shared_ptr<xmlpp::Document> document (new xmlpp::Document ());
 463                 xmlpp::Element* root = document->create_root_node ("DCinemaSecurityMessage", "http://www.smpte-ra.org/schemas/430-3/2006/ETM");
 464                 root->set_namespace_declaration ("http://www.w3.org/2000/09/xmldsig#", "ds");
 465                 root->set_namespace_declaration ("http://www.w3.org/2001/04/xmlenc#", "enc");
 466                 map<string, xmlpp::Attribute *> references;
 467                 authenticated_public.as_xml (root->add_child ("AuthenticatedPublic"), references);
 468                 authenticated_private.as_xml (root->add_child ("AuthenticatedPrivate"), references);
 469                 signature.as_xml (root->add_child ("Signature", "ds"));
 470
 471                 for (map<string, xmlpp::Attribute*>::const_iterator i = references.begin(); i != references.end(); ++i) {
 472                         xmlAddID (0, document->cobj(), (const xmlChar *) i->first.c_str(), i->second->cobj ());
 473                 }
 474
 475                 return document;
 476         }
 477
 478         AuthenticatedPublic authenticated_public;
 479         AuthenticatedPrivate authenticated_private;
 480         Signature signature;
 481 };
 482
 483 }
 484 }
 485
 486 EncryptedKDM::EncryptedKDM (boost::filesystem::path file)
 487         : _data (new data::EncryptedKDMData (shared_ptr<cxml::Node> (new cxml::Document ("DCinemaSecurityMessage", file))))
 488 {
 489
 490 }
 491
 492 EncryptedKDM::EncryptedKDM (
 493         shared_ptr<const Signer> signer,
 494         shared_ptr<const Certificate> recipient,
 495         string device_list_description,
 496         string cpl_id,
 497         string content_title_text,
 498         LocalTime not_valid_before,
 499         LocalTime not_valid_after,
 500         Formulation formulation,
 501         list<pair<string, string> > key_ids,
 502         list<string> keys
 503         )
 504         : _data (new data::EncryptedKDMData)
 505 {
 506         /* Fill our XML-ish description in with the juicy bits that the caller has given */
 507
 508         data::AuthenticatedPublic& aup = _data->authenticated_public;
 509         aup.signer.x509_issuer_name = signer->certificates().leaf()->issuer ();
 510         aup.signer.x509_serial_number = signer->certificates().leaf()->serial ();
 511
 512         data::KDMRequiredExtensions& kre = _data->authenticated_public.required_extensions.kdm_required_extensions;
 513         kre.recipient.x509_issuer_serial.x509_issuer_name = recipient->issuer ();
 514         kre.recipient.x509_issuer_serial.x509_serial_number = recipient->serial ();
 515         kre.recipient.x509_subject_name = recipient->subject ();
 516         kre.authorized_device_info.device_list_description = device_list_description;
 517         kre.composition_playlist_id = cpl_id;
 518         if (formulation == DCI_ANY || formulation == DCI_SPECIFIC) {
 519                 kre.content_authenticator = signer->certificates().leaf()->thumbprint ();
 520         }
 521         kre.content_title_text = content_title_text;
 522         kre.not_valid_before = not_valid_before;
 523         kre.not_valid_after = not_valid_after;
 524         kre.authorized_device_info.device_list_identifier = "urn:uuid:" + make_uuid ();
 525         string n = recipient->common_name ();
 526         if (n.find (".") != string::npos) {
 527                 n = n.substr (n.find (".") + 1);
 528         }
 529         kre.authorized_device_info.device_list_description = n;
 530
 531         if (formulation == MODIFIED_TRANSITIONAL_1 || formulation == DCI_ANY) {
 532                 /* Use the "assume trust" thumbprint */
 533                 kre.authorized_device_info.certificate_thumbprint = "2jmj7l5rSw0yVb/vlWAYkK/YBwk=";
 534         } else if (formulation == DCI_SPECIFIC) {
 535                 /* Use the recipient thumbprint */
 536                 kre.authorized_device_info.certificate_thumbprint = recipient->thumbprint ();
 537         }
 538
 539         for (list<pair<string, string> >::const_iterator i = key_ids.begin(); i != key_ids.end(); ++i) {
 540                 kre.key_id_list.typed_key_id.push_back (data::TypedKeyId (i->first, i->second));
 541         }
 542
 543         _data->authenticated_private.encrypted_key = keys;
 544
 545         /* Read the XML so far and sign it */
 546         shared_ptr<xmlpp::Document> doc = _data->as_xml ();
 547         xmlpp::Node::NodeList children = doc->get_root_node()->get_children ();
 548         for (xmlpp::Node::NodeList::const_iterator i = children.begin(); i != children.end(); ++i) {
 549                 if ((*i)->get_name() == "Signature") {
 550                         signer->add_signature_value (*i, "ds");
 551                 }
 552         }
 553
 554         /* Read the bits that add_signature_value did back into our variables */
 555         shared_ptr<cxml::Node> signed_doc (new cxml::Node (doc->get_root_node ()));
 556         _data->signature = data::Signature (signed_doc->node_child ("Signature"));
 557 }
 558
 559 EncryptedKDM::EncryptedKDM (EncryptedKDM const & other)
 560         : _data (new data::EncryptedKDMData (*other._data))
 561 {
 562
 563 }
 564
 565 EncryptedKDM &
 566 EncryptedKDM::operator= (EncryptedKDM const & other)
 567 {
 568         if (this == &other) {
 569                 return *this;
 570         }
 571
 572         delete _data;
 573         _data = new data::EncryptedKDMData (*other._data);
 574         return *this;
 575 }
 576
 577 EncryptedKDM::~EncryptedKDM ()
 578 {
 579         delete _data;
 580 }
 581
 582 void
 583 EncryptedKDM::as_xml (boost::filesystem::path path) const
 584 {
 585         FILE* f = fopen_boost (path, "w");
 586         string const x = as_xml ();
 587         fwrite (x.c_str(), 1, x.length(), f);
 588         fclose (f);
 589 }
 590
 591 string
 592 EncryptedKDM::as_xml () const
 593 {
 594         xmlpp::Document document;
 595         xmlpp::Element* root = document.create_root_node ("DCinemaSecurityMessage", "http://www.smpte-ra.org/schemas/430-3/2006/ETM");
 596         root->set_namespace_declaration ("http://www.w3.org/2000/09/xmldsig#", "ds");
 597         root->set_namespace_declaration ("http://www.w3.org/2001/04/xmlenc#", "enc");
 598
 599         return _data->as_xml()->write_to_string ("UTF-8");
 600 }
 601
 602 list<string>
 603 EncryptedKDM::keys () const
 604 {
 605         return _data->authenticated_private.encrypted_key;
 606 }