ceph/src/rgw/rgw_auth_keystone.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include <string>
   5 #include <vector>
   6
   7 #include <errno.h>
   8 #include <fnmatch.h>
   9
  10 #include "rgw_b64.h"
  11
  12 #include "common/errno.h"
  13 #include "common/ceph_json.h"
  14 #include "include/types.h"
  15 #include "include/str_list.h"
  16
  17 #include "rgw_common.h"
  18 #include "rgw_keystone.h"
  19 #include "rgw_auth_keystone.h"
  20 #include "rgw_keystone.h"
  21 #include "rgw_rest_s3.h"
  22 #include "rgw_auth_s3.h"
  23
  24 #include "common/ceph_crypto_cms.h"
  25 #include "common/armor.h"
  26 #include "common/Cond.h"
  27
  28 #define dout_subsys ceph_subsys_rgw
  29
  30
  31 namespace rgw {
  32 namespace auth {
  33 namespace keystone {
  34
  35 bool
  36 TokenEngine::is_applicable(const std::string& token) const noexcept
  37 {
  38   return ! token.empty() && ! cct->_conf->rgw_keystone_url.empty();
  39 }
  40
  41 TokenEngine::token_envelope_t
  42 TokenEngine::decode_pki_token(const std::string& token) const
  43 {
  44   ceph::buffer::list token_body_bl;
  45   int ret = rgw_decode_b64_cms(cct, token, token_body_bl);
  46   if (ret < 0) {
  47     ldout(cct, 20) << "cannot decode pki token" << dendl;
  48     throw ret;
  49   } else {
  50     ldout(cct, 20) << "successfully decoded pki token" << dendl;
  51   }
  52
  53   TokenEngine::token_envelope_t token_body;
  54   ret = token_body.parse(cct, token, token_body_bl, config.get_api_version());
  55   if (ret < 0) {
  56     throw ret;
  57   }
  58
  59   return token_body;
  60 }
  61
  62 boost::optional<TokenEngine::token_envelope_t>
  63 TokenEngine::get_from_keystone(const std::string& token) const
  64 {
  65   /* Unfortunately, we can't use the short form of "using" here. It's because
  66    * we're aliasing a class' member, not namespace. */
  67   using RGWValidateKeystoneToken = \
  68     rgw::keystone::Service::RGWValidateKeystoneToken;
  69
  70   /* The container for plain response obtained from Keystone. It will be
  71    * parsed token_envelope_t::parse method. */
  72   ceph::bufferlist token_body_bl;
  73   RGWValidateKeystoneToken validate(cct, &token_body_bl);
  74
  75   std::string url = config.get_endpoint_url();
  76   if (url.empty()) {
  77     throw -EINVAL;
  78   }
  79
  80   const auto keystone_version = config.get_api_version();
  81   if (keystone_version == rgw::keystone::ApiVersion::VER_2) {
  82     url.append("v2.0/tokens/" + token);
  83   } else if (keystone_version == rgw::keystone::ApiVersion::VER_3) {
  84     url.append("v3/auth/tokens");
  85     validate.append_header("X-Subject-Token", token);
  86   }
  87
  88   std::string admin_token;
  89   if (rgw::keystone::Service::get_admin_token(cct, token_cache, config,
  90                                               admin_token) < 0) {
  91     throw -EINVAL;
  92   }
  93
  94   validate.append_header("X-Auth-Token", admin_token);
  95   validate.set_send_length(0);
  96
  97   int ret = validate.process(url.c_str());
  98   if (ret < 0) {
  99     throw ret;
 100   }
 101
 102   /* NULL terminate for debug output. */
 103   token_body_bl.append(static_cast<char>(0));
 104   ldout(cct, 20) << "received response status=" << validate.get_http_status()
 105                  << ", body=" << token_body_bl.c_str() << dendl;
 106
 107   /* Detect Keystone rejection earlier than during the token parsing.
 108    * Although failure at the parsing phase doesn't impose a threat,
 109    * this allows to return proper error code (EACCESS instead of EINVAL
 110    * or similar) and thus improves logging. */
 111   if (validate.get_http_status() ==
 112           /* Most likely: wrong admin credentials or admin token. */
 113           RGWValidateKeystoneToken::HTTP_STATUS_UNAUTHORIZED ||
 114       validate.get_http_status() ==
 115           /* Most likely: non-existent token supplied by the client. */
 116           RGWValidateKeystoneToken::HTTP_STATUS_NOTFOUND) {
 117     return boost::none;
 118   }
 119
 120   TokenEngine::token_envelope_t token_body;
 121   ret = token_body.parse(cct, token, token_body_bl, config.get_api_version());
 122   if (ret < 0) {
 123     throw ret;
 124   }
 125
 126   return token_body;
 127 }
 128
 129 TokenEngine::auth_info_t
 130 TokenEngine::get_creds_info(const TokenEngine::token_envelope_t& token,
 131                             const std::vector<std::string>& admin_roles
 132                            ) const noexcept
 133 {
 134   using acct_privilege_t = rgw::auth::RemoteApplier::AuthInfo::acct_privilege_t;
 135
 136   /* Check whether the user has an admin status. */
 137   acct_privilege_t level = acct_privilege_t::IS_PLAIN_ACCT;
 138   for (const auto& admin_role : admin_roles) {
 139     if (token.has_role(admin_role)) {
 140       level = acct_privilege_t::IS_ADMIN_ACCT;
 141       break;
 142     }
 143   }
 144
 145   return auth_info_t {
 146     /* Suggested account name for the authenticated user. */
 147     rgw_user(token.get_project_id()),
 148     /* User's display name (aka real name). */
 149     token.get_project_name(),
 150     /* Keystone doesn't support RGW's subuser concept, so we cannot cut down
 151      * the access rights through the perm_mask. At least at this layer. */
 152     RGW_PERM_FULL_CONTROL,
 153     level,
 154     TYPE_KEYSTONE,
 155   };
 156 }
 157
 158 static inline const std::string
 159 make_spec_item(const std::string& tenant, const std::string& id)
 160 {
 161   return tenant + ":" + id;
 162 }
 163
 164 TokenEngine::acl_strategy_t
 165 TokenEngine::get_acl_strategy(const TokenEngine::token_envelope_t& token) const
 166 {
 167   /* The primary identity is constructed upon UUIDs. */
 168   const auto& tenant_uuid = token.get_project_id();
 169   const auto& user_uuid = token.get_user_id();
 170
 171   /* For Keystone v2 an alias may be also used. */
 172   const auto& tenant_name = token.get_project_name();
 173   const auto& user_name = token.get_user_name();
 174
 175   /* Construct all possible combinations including Swift's wildcards. */
 176   const std::array<std::string, 6> allowed_items = {
 177     make_spec_item(tenant_uuid, user_uuid),
 178     make_spec_item(tenant_name, user_name),
 179
 180     /* Wildcards. */
 181     make_spec_item(tenant_uuid, "*"),
 182     make_spec_item(tenant_name, "*"),
 183     make_spec_item("*", user_uuid),
 184     make_spec_item("*", user_name),
 185   };
 186
 187   /* Lambda will obtain a copy of (not a reference to!) allowed_items. */
 188   return [allowed_items](const rgw::auth::Identity::aclspec_t& aclspec) {
 189     uint32_t perm = 0;
 190
 191     for (const auto& allowed_item : allowed_items) {
 192       const auto iter = aclspec.find(allowed_item);
 193
 194       if (std::end(aclspec) != iter) {
 195         perm |= iter->second;
 196       }
 197     }
 198
 199     return perm;
 200   };
 201 }
 202
 203 TokenEngine::result_t
 204 TokenEngine::authenticate(const std::string& token,
 205                           const req_state* const s) const
 206 {
 207   boost::optional<TokenEngine::token_envelope_t> t;
 208
 209   /* This will be initialized on the first call to this method. In C++11 it's
 210    * also thread-safe. */
 211   static const struct RolesCacher {
 212     RolesCacher(CephContext* const cct) {
 213       get_str_vec(cct->_conf->rgw_keystone_accepted_roles, plain);
 214       get_str_vec(cct->_conf->rgw_keystone_accepted_admin_roles, admin);
 215
 216       /* Let's suppose that having an admin role implies also a regular one. */
 217       plain.insert(std::end(plain), std::begin(admin), std::end(admin));
 218     }
 219
 220     std::vector<std::string> plain;
 221     std::vector<std::string> admin;
 222   } roles(cct);
 223
 224   if (! is_applicable(token)) {
 225     return result_t::deny();
 226   }
 227
 228   /* Token ID is a concept that makes dealing with PKI tokens more effective.
 229    * Instead of storing several kilobytes, a short hash can be burried. */
 230   const auto& token_id = rgw_get_token_id(token);
 231   ldout(cct, 20) << "token_id=" << token_id << dendl;
 232
 233   /* Check cache first. */
 234   t = token_cache.find(token_id);
 235   if (t) {
 236     ldout(cct, 20) << "cached token.project.id=" << t->get_project_id()
 237                    << dendl;
 238     auto apl = apl_factory->create_apl_remote(cct, s, get_acl_strategy(*t),
 239                                               get_creds_info(*t, roles.admin));
 240     return result_t::grant(std::move(apl));
 241   }
 242
 243   /* Retrieve token. */
 244   if (rgw_is_pki_token(token)) {
 245     try {
 246       t = decode_pki_token(token);
 247     } catch (...) {
 248       /* Last resort. */
 249       t = get_from_keystone(token);
 250     }
 251   } else {
 252     /* Can't decode, just go to the Keystone server for validation. */
 253     t = get_from_keystone(token);
 254   }
 255
 256   if (! t) {
 257     return result_t::deny(-EACCES);
 258   }
 259
 260   /* Verify expiration. */
 261   if (t->expired()) {
 262     ldout(cct, 0) << "got expired token: " << t->get_project_name()
 263                   << ":" << t->get_user_name()
 264                   << " expired: " << t->get_expires() << dendl;
 265     return result_t::deny();
 266   }
 267
 268   /* Check for necessary roles. */
 269   for (const auto& role : roles.plain) {
 270     if (t->has_role(role) == true) {
 271       ldout(cct, 0) << "validated token: " << t->get_project_name()
 272                     << ":" << t->get_user_name()
 273                     << " expires: " << t->get_expires() << dendl;
 274       token_cache.add(token_id, *t);
 275       auto apl = apl_factory->create_apl_remote(cct, s, get_acl_strategy(*t),
 276                                             get_creds_info(*t, roles.admin));
 277       return result_t::grant(std::move(apl));
 278     }
 279   }
 280
 281   ldout(cct, 0) << "user does not hold a matching role; required roles: "
 282                 << g_conf->rgw_keystone_accepted_roles << dendl;
 283
 284   return result_t::deny();
 285 }
 286
 287
 288 /*
 289  * Try to validate S3 auth against keystone s3token interface
 290  */
 291 std::pair<boost::optional<rgw::keystone::TokenEnvelope>, int>
 292 EC2Engine::get_from_keystone(const std::string& access_key_id,
 293                              const std::string& string_to_sign,
 294                              const std::string& signature) const
 295 {
 296   /* prepare keystone url */
 297   std::string keystone_url = config.get_endpoint_url();
 298   if (keystone_url.empty()) {
 299     throw -EINVAL;
 300   }
 301
 302   const auto api_version = config.get_api_version();
 303   if (config.get_api_version() == rgw::keystone::ApiVersion::VER_3) {
 304     keystone_url.append("v3/s3tokens");
 305   } else {
 306     keystone_url.append("v2.0/s3tokens");
 307   }
 308
 309   /* get authentication token for Keystone. */
 310   std::string admin_token;
 311   int ret = rgw::keystone::Service::get_admin_token(cct, token_cache, config,
 312                                                     admin_token);
 313   if (ret < 0) {
 314     ldout(cct, 2) << "s3 keystone: cannot get token for keystone access"
 315                   << dendl;
 316     throw ret;
 317   }
 318
 319   using RGWValidateKeystoneToken
 320     = rgw::keystone::Service::RGWValidateKeystoneToken;
 321
 322   /* The container for plain response obtained from Keystone. It will be
 323    * parsed token_envelope_t::parse method. */
 324   ceph::bufferlist token_body_bl;
 325   RGWValidateKeystoneToken validate(cct, &token_body_bl);
 326
 327   /* set required headers for keystone request */
 328   validate.append_header("X-Auth-Token", admin_token);
 329   validate.append_header("Content-Type", "application/json");
 330
 331   /* check if we want to verify keystone's ssl certs */
 332   validate.set_verify_ssl(cct->_conf->rgw_keystone_verify_ssl);
 333
 334   /* create json credentials request body */
 335   JSONFormatter credentials(false);
 336   credentials.open_object_section("");
 337   credentials.open_object_section("credentials");
 338   credentials.dump_string("access", access_key_id);
 339   credentials.dump_string("token", rgw::to_base64(string_to_sign));
 340   credentials.dump_string("signature", signature);
 341   credentials.close_section();
 342   credentials.close_section();
 343
 344   std::stringstream os;
 345   credentials.flush(os);
 346   validate.set_post_data(os.str());
 347   validate.set_send_length(os.str().length());
 348
 349   /* send request */
 350   ret = validate.process("POST", keystone_url.c_str());
 351   if (ret < 0) {
 352     ldout(cct, 2) << "s3 keystone: token validation ERROR: "
 353                   << token_body_bl.c_str() << dendl;
 354     throw ret;
 355   }
 356
 357   /* if the supplied signature is wrong, we will get 401 from Keystone */
 358   if (validate.get_http_status() ==
 359           decltype(validate)::HTTP_STATUS_UNAUTHORIZED) {
 360     return std::make_pair(boost::none, -ERR_SIGNATURE_NO_MATCH);
 361   } else if (validate.get_http_status() ==
 362           decltype(validate)::HTTP_STATUS_NOTFOUND) {
 363     return std::make_pair(boost::none, -ERR_INVALID_ACCESS_KEY);
 364   }
 365
 366   /* now parse response */
 367   rgw::keystone::TokenEnvelope token_envelope;
 368   ret = token_envelope.parse(cct, std::string(), token_body_bl, api_version);
 369   if (ret < 0) {
 370     ldout(cct, 2) << "s3 keystone: token parsing failed, ret=0" << ret
 371                   << dendl;
 372     throw ret;
 373   }
 374
 375   return std::make_pair(std::move(token_envelope), 0);
 376 }
 377
 378 EC2Engine::acl_strategy_t
 379 EC2Engine::get_acl_strategy(const EC2Engine::token_envelope_t&) const
 380 {
 381   /* This is based on the assumption that the default acl strategy in
 382    * get_perms_from_aclspec, will take care. Extra acl spec is not required. */
 383   return nullptr;
 384 }
 385
 386 EC2Engine::auth_info_t
 387 EC2Engine::get_creds_info(const EC2Engine::token_envelope_t& token,
 388                           const std::vector<std::string>& admin_roles
 389                          ) const noexcept
 390 {
 391   using acct_privilege_t = \
 392     rgw::auth::RemoteApplier::AuthInfo::acct_privilege_t;
 393
 394   /* Check whether the user has an admin status. */
 395   acct_privilege_t level = acct_privilege_t::IS_PLAIN_ACCT;
 396   for (const auto& admin_role : admin_roles) {
 397     if (token.has_role(admin_role)) {
 398       level = acct_privilege_t::IS_ADMIN_ACCT;
 399       break;
 400     }
 401   }
 402
 403   return auth_info_t {
 404     /* Suggested account name for the authenticated user. */
 405     rgw_user(token.get_project_id()),
 406     /* User's display name (aka real name). */
 407     token.get_project_name(),
 408     /* Keystone doesn't support RGW's subuser concept, so we cannot cut down
 409      * the access rights through the perm_mask. At least at this layer. */
 410     RGW_PERM_FULL_CONTROL,
 411     level,
 412     TYPE_KEYSTONE,
 413   };
 414 }
 415
 416 rgw::auth::Engine::result_t EC2Engine::authenticate(const std::string& access_key_id,
 417                                                     const std::string& signature,
 418                                                     const std::string& string_to_sign,
 419                                                     /* Passthorugh only! */
 420                                                     const req_state* s) const
 421 {
 422   /* This will be initialized on the first call to this method. In C++11 it's
 423    * also thread-safe. */
 424   static const struct RolesCacher {
 425     RolesCacher(CephContext* const cct) {
 426       get_str_vec(cct->_conf->rgw_keystone_accepted_roles, plain);
 427       get_str_vec(cct->_conf->rgw_keystone_accepted_admin_roles, admin);
 428
 429       /* Let's suppose that having an admin role implies also a regular one. */
 430       plain.insert(std::end(plain), std::begin(admin), std::end(admin));
 431     }
 432
 433     std::vector<std::string> plain;
 434     std::vector<std::string> admin;
 435   } accepted_roles(cct);
 436
 437   boost::optional<token_envelope_t> t;
 438   int failure_reason;
 439   std::tie(t, failure_reason) = \
 440     get_from_keystone(access_key_id, string_to_sign, signature);
 441   if (! t) {
 442     return result_t::deny(failure_reason);
 443   }
 444
 445   /* Verify expiration. */
 446   if (t->expired()) {
 447     ldout(cct, 0) << "got expired token: " << t->get_project_name()
 448                   << ":" << t->get_user_name()
 449                   << " expired: " << t->get_expires() << dendl;
 450     return result_t::deny();
 451   }
 452
 453   /* check if we have a valid role */
 454   bool found = false;
 455   for (const auto& role : accepted_roles.plain) {
 456     if (t->has_role(role) == true) {
 457       found = true;
 458       break;
 459     }
 460   }
 461
 462   if (! found) {
 463     ldout(cct, 5) << "s3 keystone: user does not hold a matching role;"
 464                      " required roles: "
 465                   << cct->_conf->rgw_keystone_accepted_roles << dendl;
 466     return result_t::deny();
 467   } else {
 468     /* everything seems fine, continue with this user */
 469     ldout(cct, 5) << "s3 keystone: validated token: " << t->get_project_name()
 470                   << ":" << t->get_user_name()
 471                   << " expires: " << t->get_expires() << dendl;
 472
 473     auto apl = apl_factory->create_apl_remote(cct, s, get_acl_strategy(*t),
 474                                               get_creds_info(*t, accepted_roles.admin));
 475     return result_t::grant(std::move(apl));
 476   }
 477 }
 478
 479 }; /* namespace keystone */
 480 }; /* namespace auth */
 481 }; /* namespace rgw */