src/chromeos/network/onc/onc_utils.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chromeos/network/onc/onc_utils.h"
   6
   7 #include "base/base64.h"
   8 #include "base/json/json_reader.h"
   9 #include "base/logging.h"
  10 #include "base/metrics/histogram.h"
  11 #include "base/strings/string_util.h"
  12 #include "base/values.h"
  13 #include "chromeos/network/network_event_log.h"
  14 #include "chromeos/network/onc/onc_mapper.h"
  15 #include "chromeos/network/onc/onc_signature.h"
  16 #include "chromeos/network/onc/onc_utils.h"
  17 #include "chromeos/network/onc/onc_validator.h"
  18 #include "crypto/encryptor.h"
  19 #include "crypto/hmac.h"
  20 #include "crypto/symmetric_key.h"
  21 #include "net/cert/pem_tokenizer.h"
  22 #include "net/cert/x509_certificate.h"
  23
  24 #define ONC_LOG_WARNING(message) NET_LOG_WARNING("ONC", message)
  25 #define ONC_LOG_ERROR(message) NET_LOG_ERROR("ONC", message)
  26
  27 using namespace ::onc;
  28
  29 namespace chromeos {
  30 namespace onc {
  31
  32 namespace {
  33
  34 const char kUnableToDecrypt[] = "Unable to decrypt encrypted ONC";
  35 const char kUnableToDecode[] = "Unable to decode encrypted ONC";
  36
  37 }  // namespace
  38
  39 const char kEmptyUnencryptedConfiguration[] =
  40     "{\"Type\":\"UnencryptedConfiguration\",\"NetworkConfigurations\":[],"
  41     "\"Certificates\":[]}";
  42
  43 scoped_ptr<base::DictionaryValue> ReadDictionaryFromJson(
  44     const std::string& json) {
  45   std::string error;
  46   base::Value* root = base::JSONReader::ReadAndReturnError(
  47       json, base::JSON_ALLOW_TRAILING_COMMAS, NULL, &error);
  48
  49   base::DictionaryValue* dict_ptr = NULL;
  50   if (!root || !root->GetAsDictionary(&dict_ptr)) {
  51     ONC_LOG_ERROR("Invalid JSON Dictionary: " + error);
  52     delete root;
  53   }
  54
  55   return make_scoped_ptr(dict_ptr);
  56 }
  57
  58 scoped_ptr<base::DictionaryValue> Decrypt(const std::string& passphrase,
  59                                           const base::DictionaryValue& root) {
  60   const int kKeySizeInBits = 256;
  61   const int kMaxIterationCount = 500000;
  62   std::string onc_type;
  63   std::string initial_vector;
  64   std::string salt;
  65   std::string cipher;
  66   std::string stretch_method;
  67   std::string hmac_method;
  68   std::string hmac;
  69   int iterations;
  70   std::string ciphertext;
  71
  72   if (!root.GetString(encrypted::kCiphertext, &ciphertext) ||
  73       !root.GetString(encrypted::kCipher, &cipher) ||
  74       !root.GetString(encrypted::kHMAC, &hmac) ||
  75       !root.GetString(encrypted::kHMACMethod, &hmac_method) ||
  76       !root.GetString(encrypted::kIV, &initial_vector) ||
  77       !root.GetInteger(encrypted::kIterations, &iterations) ||
  78       !root.GetString(encrypted::kSalt, &salt) ||
  79       !root.GetString(encrypted::kStretch, &stretch_method) ||
  80       !root.GetString(toplevel_config::kType, &onc_type) ||
  81       onc_type != toplevel_config::kEncryptedConfiguration) {
  82
  83     ONC_LOG_ERROR("Encrypted ONC malformed.");
  84     return scoped_ptr<base::DictionaryValue>();
  85   }
  86
  87   if (hmac_method != encrypted::kSHA1 ||
  88       cipher != encrypted::kAES256 ||
  89       stretch_method != encrypted::kPBKDF2) {
  90     ONC_LOG_ERROR("Encrypted ONC unsupported encryption scheme.");
  91     return scoped_ptr<base::DictionaryValue>();
  92   }
  93
  94   // Make sure iterations != 0, since that's not valid.
  95   if (iterations == 0) {
  96     ONC_LOG_ERROR(kUnableToDecrypt);
  97     return scoped_ptr<base::DictionaryValue>();
  98   }
  99
 100   // Simply a sanity check to make sure we can't lock up the machine
 101   // for too long with a huge number (or a negative number).
 102   if (iterations < 0 || iterations > kMaxIterationCount) {
 103     ONC_LOG_ERROR("Too many iterations in encrypted ONC");
 104     return scoped_ptr<base::DictionaryValue>();
 105   }
 106
 107   if (!base::Base64Decode(salt, &salt)) {
 108     ONC_LOG_ERROR(kUnableToDecode);
 109     return scoped_ptr<base::DictionaryValue>();
 110   }
 111
 112   scoped_ptr<crypto::SymmetricKey> key(
 113       crypto::SymmetricKey::DeriveKeyFromPassword(crypto::SymmetricKey::AES,
 114                                                   passphrase,
 115                                                   salt,
 116                                                   iterations,
 117                                                   kKeySizeInBits));
 118
 119   if (!base::Base64Decode(initial_vector, &initial_vector)) {
 120     ONC_LOG_ERROR(kUnableToDecode);
 121     return scoped_ptr<base::DictionaryValue>();
 122   }
 123   if (!base::Base64Decode(ciphertext, &ciphertext)) {
 124     ONC_LOG_ERROR(kUnableToDecode);
 125     return scoped_ptr<base::DictionaryValue>();
 126   }
 127   if (!base::Base64Decode(hmac, &hmac)) {
 128     ONC_LOG_ERROR(kUnableToDecode);
 129     return scoped_ptr<base::DictionaryValue>();
 130   }
 131
 132   crypto::HMAC hmac_verifier(crypto::HMAC::SHA1);
 133   if (!hmac_verifier.Init(key.get()) ||
 134       !hmac_verifier.Verify(ciphertext, hmac)) {
 135     ONC_LOG_ERROR(kUnableToDecrypt);
 136     return scoped_ptr<base::DictionaryValue>();
 137   }
 138
 139   crypto::Encryptor decryptor;
 140   if (!decryptor.Init(key.get(), crypto::Encryptor::CBC, initial_vector))  {
 141     ONC_LOG_ERROR(kUnableToDecrypt);
 142     return scoped_ptr<base::DictionaryValue>();
 143   }
 144
 145   std::string plaintext;
 146   if (!decryptor.Decrypt(ciphertext, &plaintext)) {
 147     ONC_LOG_ERROR(kUnableToDecrypt);
 148     return scoped_ptr<base::DictionaryValue>();
 149   }
 150
 151   scoped_ptr<base::DictionaryValue> new_root =
 152       ReadDictionaryFromJson(plaintext);
 153   if (new_root.get() == NULL) {
 154     ONC_LOG_ERROR("Property dictionary malformed.");
 155     return scoped_ptr<base::DictionaryValue>();
 156   }
 157
 158   return new_root.Pass();
 159 }
 160
 161 std::string GetSourceAsString(ONCSource source) {
 162   switch (source) {
 163     case ONC_SOURCE_DEVICE_POLICY:
 164       return "device policy";
 165     case ONC_SOURCE_USER_POLICY:
 166       return "user policy";
 167     case ONC_SOURCE_NONE:
 168       return "none";
 169     case ONC_SOURCE_USER_IMPORT:
 170       return "user import";
 171   }
 172   NOTREACHED() << "unknown ONC source " << source;
 173   return "unknown";
 174 }
 175
 176 void ExpandField(const std::string& fieldname,
 177                  const StringSubstitution& substitution,
 178                  base::DictionaryValue* onc_object) {
 179   std::string user_string;
 180   if (!onc_object->GetStringWithoutPathExpansion(fieldname, &user_string))
 181     return;
 182
 183   std::string login_id;
 184   if (substitution.GetSubstitute(substitutes::kLoginIDField, &login_id)) {
 185     ReplaceSubstringsAfterOffset(&user_string, 0,
 186                                  substitutes::kLoginIDField,
 187                                  login_id);
 188   }
 189
 190   std::string email;
 191   if (substitution.GetSubstitute(substitutes::kEmailField, &email)) {
 192     ReplaceSubstringsAfterOffset(&user_string, 0,
 193                                  substitutes::kEmailField,
 194                                  email);
 195   }
 196
 197   onc_object->SetStringWithoutPathExpansion(fieldname, user_string);
 198 }
 199
 200 void ExpandStringsInOncObject(
 201     const OncValueSignature& signature,
 202     const StringSubstitution& substitution,
 203     base::DictionaryValue* onc_object) {
 204   if (&signature == &kEAPSignature) {
 205     ExpandField(eap::kAnonymousIdentity, substitution, onc_object);
 206     ExpandField(eap::kIdentity, substitution, onc_object);
 207   } else if (&signature == &kL2TPSignature ||
 208              &signature == &kOpenVPNSignature) {
 209     ExpandField(vpn::kUsername, substitution, onc_object);
 210   }
 211
 212   // Recurse into nested objects.
 213   for (base::DictionaryValue::Iterator it(*onc_object); !it.IsAtEnd();
 214        it.Advance()) {
 215     base::DictionaryValue* inner_object = NULL;
 216     if (!onc_object->GetDictionaryWithoutPathExpansion(it.key(), &inner_object))
 217       continue;
 218
 219     const OncFieldSignature* field_signature =
 220         GetFieldSignature(signature, it.key());
 221     if (!field_signature)
 222       continue;
 223
 224     ExpandStringsInOncObject(*field_signature->value_signature,
 225                              substitution, inner_object);
 226   }
 227 }
 228
 229 void ExpandStringsInNetworks(const StringSubstitution& substitution,
 230                              base::ListValue* network_configs) {
 231   for (base::ListValue::iterator it = network_configs->begin();
 232        it != network_configs->end(); ++it) {
 233     base::DictionaryValue* network = NULL;
 234     (*it)->GetAsDictionary(&network);
 235     DCHECK(network);
 236     ExpandStringsInOncObject(
 237         kNetworkConfigurationSignature, substitution, network);
 238   }
 239 }
 240
 241 namespace {
 242
 243 class OncMaskValues : public Mapper {
 244  public:
 245   static scoped_ptr<base::DictionaryValue> Mask(
 246       const OncValueSignature& signature,
 247       const base::DictionaryValue& onc_object,
 248       const std::string& mask) {
 249     OncMaskValues masker(mask);
 250     bool unused_error;
 251     return masker.MapObject(signature, onc_object, &unused_error);
 252   }
 253
 254  protected:
 255   explicit OncMaskValues(const std::string& mask)
 256       : mask_(mask) {
 257   }
 258
 259   virtual scoped_ptr<base::Value> MapField(
 260       const std::string& field_name,
 261       const OncValueSignature& object_signature,
 262       const base::Value& onc_value,
 263       bool* found_unknown_field,
 264       bool* error) OVERRIDE {
 265     if (FieldIsCredential(object_signature, field_name)) {
 266       return scoped_ptr<base::Value>(new base::StringValue(mask_));
 267     } else {
 268       return Mapper::MapField(field_name, object_signature, onc_value,
 269                               found_unknown_field, error);
 270     }
 271   }
 272
 273   // Mask to insert in place of the sensitive values.
 274   std::string mask_;
 275 };
 276
 277 }  // namespace
 278
 279 scoped_ptr<base::DictionaryValue> MaskCredentialsInOncObject(
 280     const OncValueSignature& signature,
 281     const base::DictionaryValue& onc_object,
 282     const std::string& mask) {
 283   return OncMaskValues::Mask(signature, onc_object, mask);
 284 }
 285
 286 namespace {
 287
 288 std::string DecodePEM(const std::string& pem_encoded) {
 289   // The PEM block header used for DER certificates
 290   const char kCertificateHeader[] = "CERTIFICATE";
 291
 292   // This is an older PEM marker for DER certificates.
 293   const char kX509CertificateHeader[] = "X509 CERTIFICATE";
 294
 295   std::vector<std::string> pem_headers;
 296   pem_headers.push_back(kCertificateHeader);
 297   pem_headers.push_back(kX509CertificateHeader);
 298
 299   net::PEMTokenizer pem_tokenizer(pem_encoded, pem_headers);
 300   std::string decoded;
 301   if (pem_tokenizer.GetNext()) {
 302     decoded = pem_tokenizer.data();
 303   } else {
 304     // If we failed to read the data as a PEM file, then try plain base64 decode
 305     // in case the PEM marker strings are missing. For this to work, there has
 306     // to be no white space, and it has to only contain the base64-encoded data.
 307     if (!base::Base64Decode(pem_encoded, &decoded)) {
 308       LOG(ERROR) << "Unable to base64 decode X509 data: " << pem_encoded;
 309       return std::string();
 310     }
 311   }
 312   return decoded;
 313 }
 314
 315 CertPEMsByGUIDMap GetServerAndCACertsByGUID(
 316     const base::ListValue& certificates) {
 317   CertPEMsByGUIDMap certs_by_guid;
 318   for (base::ListValue::const_iterator it = certificates.begin();
 319       it != certificates.end(); ++it) {
 320     base::DictionaryValue* cert = NULL;
 321     (*it)->GetAsDictionary(&cert);
 322
 323     std::string guid;
 324     cert->GetStringWithoutPathExpansion(certificate::kGUID, &guid);
 325     std::string cert_type;
 326     cert->GetStringWithoutPathExpansion(certificate::kType, &cert_type);
 327     if (cert_type != certificate::kServer &&
 328         cert_type != certificate::kAuthority) {
 329       continue;
 330     }
 331     std::string x509_data;
 332     cert->GetStringWithoutPathExpansion(certificate::kX509, &x509_data);
 333
 334     std::string der = DecodePEM(x509_data);
 335     std::string pem;
 336     if (der.empty() || !net::X509Certificate::GetPEMEncodedFromDER(der, &pem)) {
 337       LOG(ERROR) << "Certificate with GUID " << guid
 338                  << " is not in PEM encoding.";
 339       continue;
 340     }
 341     certs_by_guid[guid] = pem;
 342   }
 343
 344   return certs_by_guid;
 345 }
 346
 347 }  // namespace
 348
 349 bool ParseAndValidateOncForImport(const std::string& onc_blob,
 350                                   ONCSource onc_source,
 351                                   const std::string& passphrase,
 352                                   base::ListValue* network_configs,
 353                                   base::DictionaryValue* global_network_config,
 354                                   base::ListValue* certificates) {
 355   network_configs->Clear();
 356   global_network_config->Clear();
 357   certificates->Clear();
 358   if (onc_blob.empty())
 359     return true;
 360
 361   scoped_ptr<base::DictionaryValue> toplevel_onc =
 362       ReadDictionaryFromJson(onc_blob);
 363   if (toplevel_onc.get() == NULL) {
 364     LOG(ERROR) << "ONC loaded from " << GetSourceAsString(onc_source)
 365                << " is not a valid JSON dictionary.";
 366     return false;
 367   }
 368
 369   // Check and see if this is an encrypted ONC file. If so, decrypt it.
 370   std::string onc_type;
 371   toplevel_onc->GetStringWithoutPathExpansion(toplevel_config::kType,
 372                                               &onc_type);
 373   if (onc_type == toplevel_config::kEncryptedConfiguration) {
 374     toplevel_onc = Decrypt(passphrase, *toplevel_onc);
 375     if (toplevel_onc.get() == NULL) {
 376       LOG(ERROR) << "Couldn't decrypt the ONC from "
 377                  << GetSourceAsString(onc_source);
 378       return false;
 379     }
 380   }
 381
 382   bool from_policy = (onc_source == ONC_SOURCE_USER_POLICY ||
 383                       onc_source == ONC_SOURCE_DEVICE_POLICY);
 384
 385   // Validate the ONC dictionary. We are liberal and ignore unknown field
 386   // names and ignore invalid field names in kRecommended arrays.
 387   Validator validator(false,  // Ignore unknown fields.
 388                       false,  // Ignore invalid recommended field names.
 389                       true,   // Fail on missing fields.
 390                       from_policy);
 391   validator.SetOncSource(onc_source);
 392
 393   Validator::Result validation_result;
 394   toplevel_onc = validator.ValidateAndRepairObject(
 395       &kToplevelConfigurationSignature,
 396       *toplevel_onc,
 397       &validation_result);
 398
 399   if (from_policy) {
 400     UMA_HISTOGRAM_BOOLEAN("Enterprise.ONC.PolicyValidation",
 401                           validation_result == Validator::VALID);
 402   }
 403
 404   bool success = true;
 405   if (validation_result == Validator::VALID_WITH_WARNINGS) {
 406     LOG(WARNING) << "ONC from " << GetSourceAsString(onc_source)
 407                  << " produced warnings.";
 408     success = false;
 409   } else if (validation_result == Validator::INVALID || toplevel_onc == NULL) {
 410     LOG(ERROR) << "ONC from " << GetSourceAsString(onc_source)
 411                << " is invalid and couldn't be repaired.";
 412     return false;
 413   }
 414
 415   base::ListValue* validated_certs = NULL;
 416   if (toplevel_onc->GetListWithoutPathExpansion(toplevel_config::kCertificates,
 417                                                 &validated_certs)) {
 418     certificates->Swap(validated_certs);
 419   }
 420
 421   base::ListValue* validated_networks = NULL;
 422   if (toplevel_onc->GetListWithoutPathExpansion(
 423           toplevel_config::kNetworkConfigurations, &validated_networks)) {
 424     CertPEMsByGUIDMap server_and_ca_certs =
 425         GetServerAndCACertsByGUID(*certificates);
 426
 427     if (!ResolveServerCertRefsInNetworks(server_and_ca_certs,
 428                                          validated_networks)) {
 429       LOG(ERROR) << "Some certificate references in the ONC policy for source "
 430                  << GetSourceAsString(onc_source) << " could not be resolved.";
 431       success = false;
 432     }
 433
 434     ResolveServerCertRefsInNetworks(server_and_ca_certs, validated_networks);
 435     network_configs->Swap(validated_networks);
 436   }
 437
 438   base::DictionaryValue* validated_global_config = NULL;
 439   if (toplevel_onc->GetDictionaryWithoutPathExpansion(
 440           toplevel_config::kGlobalNetworkConfiguration,
 441           &validated_global_config)) {
 442     global_network_config->Swap(validated_global_config);
 443   }
 444
 445   return success;
 446 }
 447
 448 scoped_refptr<net::X509Certificate> DecodePEMCertificate(
 449     const std::string& pem_encoded) {
 450   std::string decoded = DecodePEM(pem_encoded);
 451   scoped_refptr<net::X509Certificate> cert =
 452       net::X509Certificate::CreateFromBytes(decoded.data(), decoded.size());
 453   LOG_IF(ERROR, !cert.get()) << "Couldn't create certificate from X509 data: "
 454                              << decoded;
 455   return cert;
 456 }
 457
 458 namespace {
 459
 460 bool GUIDRefToPEMEncoding(const CertPEMsByGUIDMap& certs_by_guid,
 461                           const std::string& guid_ref,
 462                           std::string* pem_encoded) {
 463   CertPEMsByGUIDMap::const_iterator it = certs_by_guid.find(guid_ref);
 464   if (it == certs_by_guid.end()) {
 465     LOG(ERROR) << "Couldn't resolve certificate reference " << guid_ref;
 466     return false;
 467   }
 468   *pem_encoded = it->second;
 469   if (pem_encoded->empty()) {
 470     LOG(ERROR) << "Couldn't PEM-encode certificate with GUID " << guid_ref;
 471     return false;
 472   }
 473   return true;
 474 }
 475
 476 bool ResolveSingleCertRef(const CertPEMsByGUIDMap& certs_by_guid,
 477                           const std::string& key_guid_ref,
 478                           const std::string& key_pem,
 479                           base::DictionaryValue* onc_object) {
 480   std::string guid_ref;
 481   if (!onc_object->GetStringWithoutPathExpansion(key_guid_ref, &guid_ref))
 482     return true;
 483
 484   std::string pem_encoded;
 485   if (!GUIDRefToPEMEncoding(certs_by_guid, guid_ref, &pem_encoded))
 486     return false;
 487
 488   onc_object->RemoveWithoutPathExpansion(key_guid_ref, NULL);
 489   onc_object->SetStringWithoutPathExpansion(key_pem, pem_encoded);
 490   return true;
 491 }
 492
 493 bool ResolveCertRefList(const CertPEMsByGUIDMap& certs_by_guid,
 494                         const std::string& key_guid_ref_list,
 495                         const std::string& key_pem_list,
 496                         base::DictionaryValue* onc_object) {
 497   const base::ListValue* guid_ref_list = NULL;
 498   if (!onc_object->GetListWithoutPathExpansion(key_guid_ref_list,
 499                                                &guid_ref_list)) {
 500     return true;
 501   }
 502
 503   scoped_ptr<base::ListValue> pem_list(new base::ListValue);
 504   for (base::ListValue::const_iterator it = guid_ref_list->begin();
 505        it != guid_ref_list->end(); ++it) {
 506     std::string guid_ref;
 507     (*it)->GetAsString(&guid_ref);
 508
 509     std::string pem_encoded;
 510     if (!GUIDRefToPEMEncoding(certs_by_guid, guid_ref, &pem_encoded))
 511       return false;
 512
 513     pem_list->AppendString(pem_encoded);
 514   }
 515
 516   onc_object->RemoveWithoutPathExpansion(key_guid_ref_list, NULL);
 517   onc_object->SetWithoutPathExpansion(key_pem_list, pem_list.release());
 518   return true;
 519 }
 520
 521 bool ResolveSingleCertRefToList(const CertPEMsByGUIDMap& certs_by_guid,
 522                                 const std::string& key_guid_ref,
 523                                 const std::string& key_pem_list,
 524                                 base::DictionaryValue* onc_object) {
 525   std::string guid_ref;
 526   if (!onc_object->GetStringWithoutPathExpansion(key_guid_ref, &guid_ref))
 527     return true;
 528
 529   std::string pem_encoded;
 530   if (!GUIDRefToPEMEncoding(certs_by_guid, guid_ref, &pem_encoded))
 531     return false;
 532
 533   scoped_ptr<base::ListValue> pem_list(new base::ListValue);
 534   pem_list->AppendString(pem_encoded);
 535   onc_object->RemoveWithoutPathExpansion(key_guid_ref, NULL);
 536   onc_object->SetWithoutPathExpansion(key_pem_list, pem_list.release());
 537   return true;
 538 }
 539
 540 bool ResolveServerCertRefsInObject(const CertPEMsByGUIDMap& certs_by_guid,
 541                                    const OncValueSignature& signature,
 542                                    base::DictionaryValue* onc_object) {
 543   if (&signature == &kCertificatePatternSignature) {
 544     if (!ResolveCertRefList(certs_by_guid, certificate::kIssuerCARef,
 545                             certificate::kIssuerCAPEMs, onc_object)) {
 546       return false;
 547     }
 548   } else if (&signature == &kEAPSignature) {
 549     if (!ResolveSingleCertRefToList(certs_by_guid, eap::kServerCARef,
 550                                     eap::kServerCAPEMs, onc_object)) {
 551       return false;
 552     }
 553   } else if (&signature == &kIPsecSignature) {
 554     if (!ResolveSingleCertRefToList(certs_by_guid, ipsec::kServerCARef,
 555                                     ipsec::kServerCAPEMs, onc_object)) {
 556       return false;
 557     }
 558   } else if (&signature == &kIPsecSignature ||
 559              &signature == &kOpenVPNSignature) {
 560     if (!ResolveSingleCertRef(certs_by_guid, openvpn::kServerCertRef,
 561                               openvpn::kServerCertPEM, onc_object) ||
 562         !ResolveSingleCertRefToList(certs_by_guid, openvpn::kServerCARef,
 563                                     openvpn::kServerCAPEMs, onc_object)) {
 564       return false;
 565     }
 566   }
 567
 568   // Recurse into nested objects.
 569   for (base::DictionaryValue::Iterator it(*onc_object); !it.IsAtEnd();
 570        it.Advance()) {
 571     base::DictionaryValue* inner_object = NULL;
 572     if (!onc_object->GetDictionaryWithoutPathExpansion(it.key(), &inner_object))
 573       continue;
 574
 575     const OncFieldSignature* field_signature =
 576         GetFieldSignature(signature, it.key());
 577     if (!field_signature)
 578       continue;
 579
 580     if (!ResolveServerCertRefsInObject(certs_by_guid,
 581                                        *field_signature->value_signature,
 582                                        inner_object)) {
 583       return false;
 584     }
 585   }
 586   return true;
 587 }
 588
 589 }  // namespace
 590
 591 bool ResolveServerCertRefsInNetworks(const CertPEMsByGUIDMap& certs_by_guid,
 592                                      base::ListValue* network_configs) {
 593   bool success = true;
 594   for (base::ListValue::iterator it = network_configs->begin();
 595        it != network_configs->end(); ) {
 596     base::DictionaryValue* network = NULL;
 597     (*it)->GetAsDictionary(&network);
 598     if (!ResolveServerCertRefsInNetwork(certs_by_guid, network)) {
 599       std::string guid;
 600       network->GetStringWithoutPathExpansion(network_config::kGUID, &guid);
 601       // This might happen even with correct validation, if the referenced
 602       // certificate couldn't be imported.
 603       LOG(ERROR) << "Couldn't resolve some certificate reference of network "
 604                  << guid;
 605       it = network_configs->Erase(it, NULL);
 606       success = false;
 607       continue;
 608     }
 609     ++it;
 610   }
 611   return success;
 612 }
 613
 614 bool ResolveServerCertRefsInNetwork(const CertPEMsByGUIDMap& certs_by_guid,
 615                                     base::DictionaryValue* network_config) {
 616   return ResolveServerCertRefsInObject(certs_by_guid,
 617                                        kNetworkConfigurationSignature,
 618                                        network_config);
 619 }
 620
 621 }  // namespace onc
 622 }  // namespace chromeos