Alexander Afanasyev | 7e72141 | 2017-01-11 13:36:08 -0800 | [diff] [blame] | 1 | /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ |
| 2 | /** |
| 3 | * Copyright (c) 2013-2017 Regents of the University of California. |
| 4 | * |
| 5 | * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions). |
| 6 | * |
| 7 | * ndn-cxx library is free software: you can redistribute it and/or modify it under the |
| 8 | * terms of the GNU Lesser General Public License as published by the Free Software |
| 9 | * Foundation, either version 3 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY |
| 12 | * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A |
| 13 | * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. |
| 14 | * |
| 15 | * You should have received copies of the GNU General Public License and GNU Lesser |
| 16 | * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see |
| 17 | * <http://www.gnu.org/licenses/>. |
| 18 | * |
| 19 | * See AUTHORS.md for complete list of ndn-cxx authors and contributors. |
| 20 | */ |
| 21 | |
| 22 | #ifndef NDN_SECURITY_V2_VALIDATION_STATE_HPP |
| 23 | #define NDN_SECURITY_V2_VALIDATION_STATE_HPP |
| 24 | |
| 25 | #include "../../tag-host.hpp" |
| 26 | #include "validation-callback.hpp" |
| 27 | #include "certificate.hpp" |
Alexander Afanasyev | 9333887 | 2017-01-30 22:37:00 -0800 | [diff] [blame^] | 28 | #include "../../util/signal.hpp" |
Alexander Afanasyev | 7e72141 | 2017-01-11 13:36:08 -0800 | [diff] [blame] | 29 | |
| 30 | #include <unordered_set> |
| 31 | #include <list> |
| 32 | |
| 33 | namespace ndn { |
| 34 | namespace security { |
| 35 | namespace v2 { |
| 36 | |
| 37 | class Validator; |
| 38 | |
| 39 | /** |
| 40 | * @brief Validation state |
| 41 | * |
| 42 | * One instance of the validation state is kept for the validation of the whole certificate |
| 43 | * chain. |
| 44 | * |
| 45 | * The state collects the certificate chain that adheres to the selected validation policy to |
| 46 | * validate data or interest packets. Certificate, data, and interest packet signatures are |
| 47 | * verified only after the validator determines that the chain terminates with a trusted |
| 48 | * certificate (a trusted anchor or a previously validated certificate). This model allows |
| 49 | * filtering out invalid certificate chains without incurring (costly) cryptographic signature |
| 50 | * verification overhead and mitigates some forms of denial-of-service attacks. |
| 51 | * |
| 52 | * Validation policy and/or key fetcher may add custom information associated with the |
| 53 | * validation state using tags (@sa TagHost) |
| 54 | * |
| 55 | * @sa DataValidationState, InterestValidationState |
| 56 | */ |
| 57 | class ValidationState : public TagHost, noncopyable |
| 58 | { |
| 59 | public: |
| 60 | /** |
| 61 | * @brief Create validation state |
| 62 | */ |
| 63 | ValidationState(); |
| 64 | |
| 65 | virtual |
| 66 | ~ValidationState(); |
| 67 | |
| 68 | /** |
| 69 | * @brief Call the failure callback |
| 70 | */ |
| 71 | virtual void |
| 72 | fail(const ValidationError& error) = 0; |
| 73 | |
| 74 | /** |
| 75 | * @return Depth of certificate chain |
| 76 | */ |
| 77 | size_t |
| 78 | getDepth() const; |
| 79 | |
| 80 | /** |
| 81 | * @brief Check if @p certName has been previously seen and record the supplied name |
| 82 | */ |
| 83 | bool |
| 84 | hasSeenCertificateName(const Name& certName); |
| 85 | |
| 86 | /** |
| 87 | * @brief Add @p cert to the top of the certificate chain |
| 88 | * |
| 89 | * If m_certificateChain is empty, @p cert should be the signer of the original |
| 90 | * packet. If m_certificateChain is not empty, @p cert should be the signer of |
| 91 | * m_certificateChain.front(). |
| 92 | * |
| 93 | * @post m_certificateChain.front() == cert |
| 94 | * @note This function does not verify the signature bits. |
| 95 | */ |
| 96 | void |
| 97 | addCertificate(const Certificate& cert); |
| 98 | |
| 99 | private: // Interface intended to be used only by Validator class |
| 100 | /** |
| 101 | * @brief Verify signature of the original packet |
| 102 | * |
| 103 | * @param trustCert The certificate that signs the original packet |
| 104 | */ |
| 105 | virtual void |
| 106 | verifyOriginalPacket(const Certificate& trustedCert) = 0; |
| 107 | |
| 108 | /** |
| 109 | * @brief Call success callback of the original packet without signature validation |
| 110 | */ |
| 111 | virtual void |
| 112 | bypassValidation() = 0; |
| 113 | |
| 114 | /** |
| 115 | * @brief Verify signatures of certificates in the certificate chain |
| 116 | * |
| 117 | * When certificate chain cannot be verified, this method will call this->fail() with |
| 118 | * INVALID_SIGNATURE error code and the appropriate diagnostic message. |
| 119 | * |
| 120 | * @retval nullptr Signatures of at least one certificate in the chain is invalid. All unverified |
| 121 | * certificates have been removed from m_certificateChain. |
| 122 | * @retval Certificate to validate original data packet, either m_certificateChain.back() or |
| 123 | * trustedCert if the certificate chain is empty. |
| 124 | * |
| 125 | * @post m_certificateChain includes a list of certificates successfully verified by |
| 126 | * @p trustedCert. |
| 127 | */ |
| 128 | const Certificate* |
| 129 | verifyCertificateChain(const Certificate& trustedCert); |
| 130 | |
| 131 | protected: |
| 132 | bool m_hasOutcome; |
| 133 | |
| 134 | private: |
| 135 | std::unordered_set<Name> m_seenCertificateNames; |
| 136 | |
| 137 | /** |
| 138 | * @brief the certificate chain |
| 139 | * |
| 140 | * Each certificate in the chain signs the next certificate. The last certificate signs the |
| 141 | * original packet. |
| 142 | */ |
| 143 | std::list<v2::Certificate> m_certificateChain; |
| 144 | |
| 145 | friend class Validator; |
| 146 | }; |
| 147 | |
| 148 | /** |
| 149 | * @brief Validation state for a data packet |
| 150 | */ |
| 151 | class DataValidationState final : public ValidationState |
| 152 | { |
| 153 | public: |
| 154 | /** |
| 155 | * @brief Create validation state for @p data |
| 156 | * |
| 157 | * The caller must ensure that state instance is valid until validation finishes (i.e., until |
| 158 | * after validateCertificateChain() and validateOriginalPacket() are called) |
| 159 | */ |
| 160 | DataValidationState(const Data& data, |
| 161 | const DataValidationSuccessCallback& successCb, |
| 162 | const DataValidationFailureCallback& failureCb); |
| 163 | |
| 164 | /** |
| 165 | * @brief Destructor |
| 166 | * |
| 167 | * If neither success callback nor failure callback was called, the destructor will call |
| 168 | * failure callback with IMPLEMENTATION_ERROR error code. |
| 169 | */ |
| 170 | ~DataValidationState() final; |
| 171 | |
| 172 | void |
| 173 | fail(const ValidationError& error) final; |
| 174 | |
| 175 | /** |
| 176 | * @return Original data being validated |
| 177 | */ |
| 178 | const Data& |
| 179 | getOriginalData() const; |
| 180 | |
| 181 | private: |
| 182 | void |
| 183 | verifyOriginalPacket(const Certificate& trustedCert) final; |
| 184 | |
| 185 | void |
| 186 | bypassValidation() final; |
| 187 | |
| 188 | private: |
| 189 | Data m_data; |
| 190 | DataValidationSuccessCallback m_successCb; |
| 191 | DataValidationFailureCallback m_failureCb; |
| 192 | }; |
| 193 | |
| 194 | /** |
| 195 | * @brief Validation state for an interest packet |
| 196 | */ |
| 197 | class InterestValidationState final : public ValidationState |
| 198 | { |
| 199 | public: |
| 200 | /** |
| 201 | * @brief Create validation state for @p interest |
| 202 | * |
| 203 | * The caller must ensure that state instance is valid until validation finishes (i.e., until |
| 204 | * after validateCertificateChain() and validateOriginalPacket() are called) |
| 205 | */ |
| 206 | InterestValidationState(const Interest& interest, |
| 207 | const InterestValidationSuccessCallback& successCb, |
| 208 | const InterestValidationFailureCallback& failureCb); |
| 209 | |
| 210 | /** |
| 211 | * @brief Destructor |
| 212 | * |
| 213 | * If neither success callback nor failure callback was called, the destructor will call |
| 214 | * failure callback with IMPLEMENTATION_ERROR error code. |
| 215 | */ |
| 216 | ~InterestValidationState() final; |
| 217 | |
| 218 | void |
| 219 | fail(const ValidationError& error) final; |
| 220 | |
| 221 | /** |
| 222 | * @return Original interest being validated |
| 223 | */ |
| 224 | const Interest& |
| 225 | getOriginalInterest() const; |
| 226 | |
Alexander Afanasyev | 9333887 | 2017-01-30 22:37:00 -0800 | [diff] [blame^] | 227 | public: |
| 228 | util::Signal<InterestValidationState, Interest> afterSuccess; |
| 229 | |
Alexander Afanasyev | 7e72141 | 2017-01-11 13:36:08 -0800 | [diff] [blame] | 230 | private: |
| 231 | void |
| 232 | verifyOriginalPacket(const Certificate& trustedCert) final; |
| 233 | |
| 234 | void |
| 235 | bypassValidation() final; |
| 236 | |
| 237 | private: |
| 238 | Interest m_interest; |
| 239 | InterestValidationSuccessCallback m_successCb; |
| 240 | InterestValidationFailureCallback m_failureCb; |
| 241 | }; |
| 242 | |
| 243 | } // namespace v2 |
| 244 | } // namespace security |
| 245 | } // namespace ndn |
| 246 | |
| 247 | #endif // NDN_SECURITY_V2_VALIDATION_STATE_HPP |