Mercurial > hg > orthanc-object-storage
annotate Common/EncryptionHelpers.cpp @ 37:f55b2afdf53d
upgrade to year 2021
| author | Sebastien Jodogne <s.jodogne@gmail.com> |
|---|---|
| date | Wed, 06 Jan 2021 18:27:54 +0100 |
| parents | 662b9d3f217d |
| children | b922ae86bbe1 |
| rev | line source |
|---|---|
| 1 | 1 /** |
| 2 * Cloud storage plugins for Orthanc | |
|
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Sebastien Jodogne <s.jodogne@gmail.com>
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3 * Copyright (C) 2020-2021 Osimis S.A., Belgium |
| 1 | 4 * |
| 5 * This program is free software: you can redistribute it and/or | |
| 6 * modify it under the terms of the GNU Affero General Public License | |
| 7 * as published by the Free Software Foundation, either version 3 of | |
| 8 * the License, or (at your option) any later version. | |
| 9 * | |
| 10 * This program is distributed in the hope that it will be useful, but | |
| 11 * WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 * Affero General Public License for more details. | |
| 14 * | |
| 15 * You should have received a copy of the GNU Affero General Public License | |
| 16 * along with this program. If not, see <http://www.gnu.org/licenses/>. | |
| 17 **/ | |
| 18 | |
| 19 #include "EncryptionHelpers.h" | |
| 20 #include <assert.h> | |
| 21 | |
| 22 #include <boost/lexical_cast.hpp> | |
| 23 #include <iostream> | |
|
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24 |
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25 #include <cryptopp/cryptlib.h> |
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26 #include <cryptopp/modes.h> |
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27 #include <cryptopp/hex.h> |
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28 #include <cryptopp/gcm.h> |
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29 #include <cryptopp/files.h> |
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30 #include <cryptopp/filters.h> |
| 1 | 31 |
| 32 const std::string EncryptionHelpers::HEADER_VERSION = "A1"; | |
| 33 | |
| 34 using namespace CryptoPP; | |
| 35 | |
|
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36 std::string EncryptionHelpers::ToHexString(const void* block, size_t size) |
| 1 | 37 { |
| 38 std::string blockAsString = std::string(reinterpret_cast<const char*>(block), size); | |
| 39 | |
| 40 return ToHexString(blockAsString); | |
| 41 } | |
| 42 | |
| 43 std::string EncryptionHelpers::ToHexString(const std::string& block) | |
| 44 { | |
| 45 std::string hexString; | |
| 46 StringSource ss(block, true, | |
| 47 new HexEncoder( | |
| 48 new StringSink(hexString) | |
| 49 ) // StreamTransformationFilter | |
| 50 ); // StringSource | |
| 51 | |
| 52 return hexString; | |
| 53 } | |
| 54 | |
| 55 std::string EncryptionHelpers::ToHexString(const SecByteBlock& block) | |
| 56 { | |
| 57 return ToHexString(ToString(block)); | |
| 58 } | |
| 59 | |
| 60 std::string EncryptionHelpers::ToString(const CryptoPP::SecByteBlock& block) | |
| 61 { | |
| 62 return std::string(reinterpret_cast<const char*>(block.data()), block.size()); | |
| 63 } | |
| 64 | |
| 65 std::string EncryptionHelpers::ToString(uint32_t value) | |
| 66 { | |
| 67 return std::string(reinterpret_cast<const char*>(&value), 4); | |
| 68 } | |
| 69 | |
| 70 void EncryptionHelpers::ReadKey(CryptoPP::SecByteBlock& key, const std::string& path) | |
| 71 { | |
| 72 try | |
| 73 { | |
| 74 FileSource fs(path.c_str(), true, | |
| 75 new HexDecoder( | |
| 76 new ArraySink(key.begin(), key.size()) | |
| 77 ) | |
| 78 ); | |
| 79 } | |
| 80 catch (CryptoPP::Exception& ex) | |
| 81 { | |
| 82 throw EncryptionException("unabled to read key from file '" + path + "': " + ex.what()); | |
| 83 } | |
| 84 } | |
| 85 | |
| 86 void EncryptionHelpers::SetCurrentMasterKey(uint32_t id, const std::string& path) | |
| 87 { | |
| 88 SecByteBlock key(AES_KEY_SIZE); | |
| 89 | |
| 90 ReadKey(key, path); | |
| 91 SetCurrentMasterKey(id, key); | |
| 92 } | |
| 93 | |
| 94 void EncryptionHelpers::AddPreviousMasterKey(uint32_t id, const std::string& path) | |
| 95 { | |
| 96 SecByteBlock key(AES_KEY_SIZE); | |
| 97 | |
| 98 ReadKey(key, path); | |
| 99 AddPreviousMasterKey(id, key); | |
| 100 } | |
| 101 | |
| 102 EncryptionHelpers::EncryptionHelpers(size_t maxConcurrentInputSize) | |
| 103 : concurrentInputSizeSemaphore_(maxConcurrentInputSize), | |
| 104 maxConcurrentInputSize_(maxConcurrentInputSize) | |
| 105 { | |
| 106 } | |
| 107 | |
| 108 void EncryptionHelpers::SetCurrentMasterKey(uint32_t id, const CryptoPP::SecByteBlock& key) | |
| 109 { | |
| 110 encryptionMasterKey_ = key; | |
| 111 encryptionMasterKeyId_ = ToString(id); | |
| 112 } | |
| 113 | |
| 114 void EncryptionHelpers::AddPreviousMasterKey(uint32_t id, const CryptoPP::SecByteBlock& key) | |
| 115 { | |
| 116 previousMasterKeys_[ToString(id)] = key; | |
| 117 } | |
| 118 | |
| 119 const CryptoPP::SecByteBlock& EncryptionHelpers::GetMasterKey(const std::string& keyId) | |
| 120 { | |
| 121 if (encryptionMasterKeyId_ == keyId) | |
| 122 { | |
| 123 return encryptionMasterKey_; | |
| 124 } | |
| 125 | |
| 126 if (previousMasterKeys_.find(keyId) == previousMasterKeys_.end()) | |
| 127 { | |
| 128 throw EncryptionException("The master key whose id is '" + ToHexString(keyId) + "' could not be found. Unable to decrypt file"); | |
| 129 } | |
| 130 | |
| 131 return previousMasterKeys_.at(keyId); | |
| 132 } | |
| 133 | |
| 134 void EncryptionHelpers::GenerateKey(CryptoPP::SecByteBlock& key) | |
| 135 { | |
| 136 AutoSeededRandomPool prng; | |
| 137 | |
| 138 SecByteBlock tempKey(AES_KEY_SIZE); | |
| 139 prng.GenerateBlock( tempKey, tempKey.size() ); | |
| 140 key = tempKey; | |
| 141 } | |
| 142 | |
| 143 void EncryptionHelpers::Encrypt(std::string &output, const std::string &input) | |
| 144 { | |
| 145 Encrypt(output, input.data(), input.size()); | |
| 146 } | |
| 147 | |
| 148 void EncryptionHelpers::Encrypt(std::string &output, const char* data, size_t size) | |
| 149 { | |
| 150 if (size > maxConcurrentInputSize_) | |
| 151 { | |
| 152 throw EncryptionException("The file is too large to encrypt: " + boost::lexical_cast<std::string>(size) + " bytes. Try increasing the MaxConcurrentInputSize"); | |
| 153 } | |
| 154 | |
| 155 Orthanc::Semaphore::Locker lock(concurrentInputSizeSemaphore_, size); | |
| 156 | |
| 157 EncryptInternal(output, data, size, encryptionMasterKey_); | |
| 158 } | |
| 159 | |
| 160 void EncryptionHelpers::Decrypt(std::string &output, const std::string &input) | |
| 161 { | |
| 162 output.resize(input.size() - OVERHEAD_SIZE); | |
| 163 Decrypt(const_cast<char*>(output.data()), input.data(), input.size()); | |
| 164 } | |
| 165 | |
| 166 void EncryptionHelpers::Decrypt(char* output, const char* data, size_t size) | |
| 167 { | |
| 168 if (size > maxConcurrentInputSize_) | |
| 169 { | |
| 170 throw EncryptionException("The file is too large to decrypt: " + boost::lexical_cast<std::string>(size) + " bytes. Try increasing the MaxConcurrentInputSize"); | |
| 171 } | |
| 172 | |
| 173 Orthanc::Semaphore::Locker lock(concurrentInputSizeSemaphore_, size); | |
| 174 | |
| 175 if (size < HEADER_VERSION_SIZE) | |
| 176 { | |
| 177 throw EncryptionException("Unable to decrypt data, no header found"); | |
| 178 } | |
| 179 | |
| 180 std::string version = std::string(data, HEADER_VERSION_SIZE); | |
| 181 | |
| 182 if (version != "A1") | |
| 183 { | |
| 184 throw EncryptionException("Unable to decrypt data, version '" + version + "' is not supported"); | |
| 185 } | |
| 186 | |
| 187 if (size < (HEADER_VERSION_SIZE + MASTER_KEY_ID_SIZE)) | |
| 188 { | |
| 189 throw EncryptionException("Unable to decrypt data, no master key id found"); | |
| 190 } | |
| 191 | |
| 192 std::string decryptionMasterKeyId = std::string(data + HEADER_VERSION_SIZE, MASTER_KEY_ID_SIZE); | |
| 193 | |
| 194 const SecByteBlock& decryptionMasterKey = GetMasterKey(decryptionMasterKeyId); | |
| 195 DecryptInternal(output, data, size, decryptionMasterKey); | |
| 196 } | |
| 197 | |
| 198 void EncryptionHelpers::EncryptPrefixSecBlock(std::string& output, const CryptoPP::SecByteBlock& input, const CryptoPP::SecByteBlock& masterKey) | |
| 199 { | |
| 200 try | |
| 201 { | |
| 202 SecByteBlock iv(16); | |
| 203 memset(iv.data(), 0, iv.size()); | |
| 204 | |
| 205 CTR_Mode<AES>::Encryption e; | |
| 206 e.SetKeyWithIV(masterKey, masterKey.size(), iv.data(), iv.size()); | |
| 207 | |
| 208 std::string inputString = ToString(input); | |
| 209 | |
| 210 // The StreamTransformationFilter adds padding | |
| 211 // as required. ECB and CBC Mode must be padded | |
| 212 // to the block size of the cipher. | |
| 213 StringSource ss(inputString, true, | |
| 214 new StreamTransformationFilter(e, | |
| 215 new StringSink(output) | |
| 216 ) // StreamTransformationFilter | |
| 217 ); // StringSource | |
| 218 } | |
| 219 catch (CryptoPP::Exception& e) | |
| 220 { | |
| 221 throw EncryptionException(e.what()); | |
| 222 } | |
| 223 | |
| 224 assert(output.size() == input.size()); | |
| 225 } | |
| 226 | |
| 227 void EncryptionHelpers::DecryptPrefixSecBlock(CryptoPP::SecByteBlock& output, const std::string& input, const CryptoPP::SecByteBlock& masterKey) | |
| 228 { | |
| 229 try | |
| 230 { | |
| 231 SecByteBlock iv(16); | |
| 232 memset(iv.data(), 0, iv.size()); | |
| 233 | |
| 234 CTR_Mode<AES>::Decryption d; | |
| 235 d.SetKeyWithIV(masterKey, masterKey.size(), iv.data(), iv.size()); | |
| 236 | |
| 237 std::string outputString; | |
| 238 | |
| 239 // The StreamTransformationFilter adds padding | |
| 240 // as required. ECB and CBC Mode must be padded | |
| 241 // to the block size of the cipher. | |
| 242 StringSource ss(input, true, | |
| 243 new StreamTransformationFilter(d, | |
| 244 new StringSink(outputString) | |
| 245 ) // StreamTransformationFilter | |
| 246 ); // StringSource | |
| 247 | |
| 248 output.Assign((const byte*)outputString.data(), outputString.size()); | |
| 249 } | |
| 250 catch (CryptoPP::Exception& e) | |
| 251 { | |
| 252 throw EncryptionException(e.what()); | |
| 253 } | |
| 254 | |
| 255 assert(output.size() == input.size()); | |
| 256 } | |
| 257 | |
| 258 | |
| 259 void EncryptionHelpers::EncryptInternal(std::string& output, const char* data, size_t size, const CryptoPP::SecByteBlock& masterKey) | |
| 260 { | |
| 261 SecByteBlock iv(IV_SIZE); | |
| 262 randomGenerator_.GenerateBlock(iv, iv.size()); // with GCM, the iv is supposed to be a nonce (not a random number). However, since each dataKey is used only once, we consider a random number is fine. | |
| 263 | |
| 264 SecByteBlock dataKey; | |
| 265 GenerateKey(dataKey); | |
| 266 | |
| 267 // std::cout << ToHexString(dataKey) << std::endl; | |
| 268 // std::cout << ToHexString(iv) << std::endl; | |
| 269 std::string encryptedDataKey; | |
| 270 std::string encryptedIv; | |
| 271 | |
| 272 EncryptPrefixSecBlock(encryptedIv, iv, masterKey); | |
| 273 EncryptPrefixSecBlock(encryptedDataKey, dataKey, masterKey); | |
| 274 | |
| 275 std::string prefix = HEADER_VERSION + encryptionMasterKeyId_ + encryptedIv + encryptedDataKey; | |
| 276 | |
| 277 try | |
| 278 { | |
| 279 GCM<AES>::Encryption e; | |
| 25 | 280 e.SetKeyWithIV(dataKey, dataKey.size(), iv, iv.size()); |
| 1 | 281 |
| 282 // the output text starts with the unencrypted prefix | |
| 283 output = prefix; | |
| 284 | |
| 285 AuthenticatedEncryptionFilter ef(e, | |
| 286 new StringSink(output), false, INTEGRITY_CHECK_TAG_SIZE | |
| 287 ); | |
| 288 | |
| 289 | |
| 290 // AuthenticatedEncryptionFilter::ChannelPut | |
| 291 // defines two channels: "" (empty) and "AAD" | |
| 292 // channel "" is encrypted and authenticated | |
| 293 // channel "AAD" is authenticated | |
| 294 ef.ChannelPut("AAD", (const byte*)prefix.data(), prefix.size()); | |
| 295 ef.ChannelMessageEnd("AAD"); | |
| 296 | |
| 297 // Authenticated data *must* be pushed before | |
| 298 // Confidential/Authenticated data. Otherwise | |
| 299 // we must catch the BadState exception | |
| 300 ef.ChannelPut("", (const byte*)data, size); | |
| 301 ef.ChannelMessageEnd(""); | |
| 302 } | |
| 303 catch(CryptoPP::Exception& e) | |
| 304 { | |
| 305 throw EncryptionException(e.what()); | |
| 306 } | |
| 307 } | |
| 308 | |
| 309 void EncryptionHelpers::DecryptInternal(char* output, const char* data, size_t size, const CryptoPP::SecByteBlock& masterKey) | |
| 310 { | |
| 311 size_t prefixSize = HEADER_VERSION_SIZE + MASTER_KEY_ID_SIZE + IV_SIZE + AES_KEY_SIZE; | |
| 312 | |
| 313 std::string prefix = std::string(data, prefixSize); | |
| 314 std::string mac = std::string(data + size - INTEGRITY_CHECK_TAG_SIZE, INTEGRITY_CHECK_TAG_SIZE); | |
| 315 | |
| 316 std::string encryptedIv = prefix.substr(HEADER_VERSION_SIZE + MASTER_KEY_ID_SIZE, IV_SIZE); | |
| 317 std::string encryptedDataKey = prefix.substr(HEADER_VERSION_SIZE + MASTER_KEY_ID_SIZE + IV_SIZE, AES_KEY_SIZE); | |
| 318 | |
| 319 SecByteBlock dataKey; | |
| 320 SecByteBlock iv; | |
| 321 | |
| 322 DecryptPrefixSecBlock(iv, encryptedIv, masterKey); | |
| 323 DecryptPrefixSecBlock(dataKey, encryptedDataKey, masterKey); | |
| 324 // std::cout << ToHexString(dataKey) << std::endl; | |
| 325 // std::cout << ToHexString(iv) << std::endl; | |
| 326 | |
| 327 GCM<AES>::Decryption d; | |
| 25 | 328 d.SetKeyWithIV(dataKey, dataKey.size(), iv, iv.size()); |
| 1 | 329 |
| 330 try { | |
| 331 AuthenticatedDecryptionFilter df(d, NULL, | |
| 332 AuthenticatedDecryptionFilter::MAC_AT_BEGIN | | |
| 333 AuthenticatedDecryptionFilter::THROW_EXCEPTION, INTEGRITY_CHECK_TAG_SIZE); | |
| 334 | |
| 335 // The order of the following calls are important | |
| 336 df.ChannelPut("", (const byte*)mac.data(), mac.size()); | |
| 337 df.ChannelPut("AAD", (const byte*)prefix.data(), prefix.size()); | |
| 338 df.ChannelPut("", (const byte*)(data) + prefixSize, size - INTEGRITY_CHECK_TAG_SIZE - prefixSize); | |
| 339 | |
| 340 // If the object throws, it will most likely occur | |
| 341 // during ChannelMessageEnd() | |
| 342 df.ChannelMessageEnd("AAD"); | |
| 343 df.ChannelMessageEnd(""); | |
| 344 | |
| 345 // If the object does not throw, here's the only | |
| 346 // opportunity to check the data's integrity | |
| 347 if (!df.GetLastResult()) | |
| 348 { | |
| 349 throw EncryptionException("The decryption filter failed for some unknown reason. Integrity check failed ?"); | |
| 350 } | |
| 351 | |
| 352 // Remove data from channel | |
| 353 size_t n = (size_t)-1; | |
| 354 | |
| 355 // Recover plain text | |
| 356 df.SetRetrievalChannel(""); | |
| 357 n = (size_t)df.MaxRetrievable(); | |
| 358 | |
| 359 if(n > 0) | |
| 360 { | |
| 361 assert(n == size - OVERHEAD_SIZE); | |
| 362 | |
| 363 df.Get((byte*)output, n); | |
| 364 } | |
| 365 } | |
| 366 catch (CryptoPP::Exception& ex) | |
| 367 { | |
| 368 throw EncryptionException(ex.what()); | |
| 369 } | |
| 370 } |