xmltooling/encryption/impl/Encrypter.cpp

   1 /*
   2  *  Copyright 2001-2010 Internet2
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /**
  18  * Encrypter.cpp
  19  *
  20  * Methods for encrypting XMLObjects and other data.
  21  */
  22
  23 #include "internal.h"
  24 #include "encryption/Encrypter.h"
  25 #include "encryption/Encryption.h"
  26 #include "security/Credential.h"
  27 #include "signature/KeyInfo.h"
  28
  29 #include <xsec/enc/XSECCryptoException.hpp>
  30 #include <xsec/framework/XSECException.hpp>
  31 #include <xsec/framework/XSECAlgorithmMapper.hpp>
  32 #include <xsec/framework/XSECAlgorithmHandler.hpp>
  33 #include <xsec/xenc/XENCCipher.hpp>
  34 #include <xsec/xenc/XENCEncryptedData.hpp>
  35 #include <xsec/xenc/XENCEncryptedKey.hpp>
  36
  37 using namespace xmlencryption;
  38 using namespace xmlsignature;
  39 using namespace xmltooling;
  40 using namespace xercesc;
  41 using namespace std;
  42
  43 Encrypter::EncryptionParams::EncryptionParams(
  44     const XMLCh* algorithm, const unsigned char* keyBuffer, unsigned int keyBufferSize, const Credential* credential, bool compact
  45     ) : m_algorithm(algorithm), m_keyBuffer(keyBuffer), m_keyBufferSize(keyBufferSize), m_credential(credential), m_compact(compact)
  46 {
  47 }
  48
  49 Encrypter::EncryptionParams::~EncryptionParams()
  50 {
  51 }
  52
  53 Encrypter::KeyEncryptionParams::KeyEncryptionParams(const Credential& credential, const XMLCh* algorithm, const XMLCh* recipient)
  54     : m_credential(credential), m_algorithm(algorithm), m_recipient(recipient)
  55 {
  56 }
  57
  58 Encrypter::KeyEncryptionParams::~KeyEncryptionParams()
  59 {
  60 }
  61
  62 Encrypter::Encrypter() : m_cipher(nullptr)
  63 {
  64 }
  65
  66 Encrypter::~Encrypter()
  67 {
  68     XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->releaseCipher(m_cipher);
  69     memset(m_keyBuffer,0,32);
  70 }
  71
  72 void Encrypter::checkParams(EncryptionParams& encParams, KeyEncryptionParams* kencParams)
  73 {
  74     if (encParams.m_keyBufferSize==0) {
  75         if (encParams.m_credential) {
  76             if (kencParams)
  77                 throw EncryptionException("Generating EncryptedKey inline requires the encryption key in raw form.");
  78         }
  79         else {
  80             if (!kencParams)
  81                 throw EncryptionException("Using a generated encryption key requires a KeyEncryptionParams object.");
  82
  83             // We're generating a random key. The maximum supported length is AES-256, so we need 32 bytes.
  84             if (XSECPlatformUtils::g_cryptoProvider->getRandom(m_keyBuffer,32)<32)
  85                 throw EncryptionException("Unable to generate random data; was PRNG seeded?");
  86             encParams.m_keyBuffer=m_keyBuffer;
  87             encParams.m_keyBufferSize=32;
  88         }
  89     }
  90
  91     XSECCryptoKey* key=nullptr;
  92     if (encParams.m_credential) {
  93         key = encParams.m_credential->getPrivateKey();
  94         if (!key)
  95             throw EncryptionException("Credential in EncryptionParams structure did not supply a private/secret key.");
  96         // Set the encryption key.
  97         m_cipher->setKey(key->clone());
  98     }
  99     else {
 100         // We have to have a raw key now, so we need to build a wrapper around it.
 101         XSECAlgorithmHandler* handler =XSECPlatformUtils::g_algorithmMapper->mapURIToHandler(encParams.m_algorithm);
 102         if (handler != nullptr)
 103             key = handler->createKeyForURI(
 104                 encParams.m_algorithm,const_cast<unsigned char*>(encParams.m_keyBuffer),encParams.m_keyBufferSize
 105                 );
 106
 107         if (!key)
 108             throw EncryptionException("Unable to build wrapper for key, unknown algorithm?");
 109         // Overwrite the length if known.
 110         switch (static_cast<XSECCryptoSymmetricKey*>(key)->getSymmetricKeyType()) {
 111             case XSECCryptoSymmetricKey::KEY_3DES_192:
 112                 encParams.m_keyBufferSize = 192/8;
 113                 break;
 114             case XSECCryptoSymmetricKey::KEY_AES_128:
 115                 encParams.m_keyBufferSize = 128/8;
 116                 break;
 117             case XSECCryptoSymmetricKey::KEY_AES_192:
 118                 encParams.m_keyBufferSize = 192/8;
 119                 break;
 120             case XSECCryptoSymmetricKey::KEY_AES_256:
 121                 encParams.m_keyBufferSize = 256/8;
 122                 break;
 123         }
 124         // Set the encryption key.
 125         m_cipher->setKey(key);
 126     }
 127 }
 128
 129 EncryptedData* Encrypter::encryptElement(DOMElement* element, EncryptionParams& encParams, KeyEncryptionParams* kencParams)
 130 {
 131     // We can reuse the cipher object if the document hasn't changed.
 132
 133     if (m_cipher && m_cipher->getDocument()!=element->getOwnerDocument()) {
 134         XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->releaseCipher(m_cipher);
 135         m_cipher=nullptr;
 136     }
 137
 138     if (!m_cipher) {
 139         m_cipher=XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->newCipher(element->getOwnerDocument());
 140         m_cipher->setExclusiveC14nSerialisation(false);
 141     }
 142
 143     try {
 144         checkParams(encParams,kencParams);
 145         m_cipher->encryptElementDetached(element, ENCRYPT_NONE, encParams.m_algorithm);
 146         return decorateAndUnmarshall(encParams, kencParams);
 147     }
 148     catch(XSECException& e) {
 149         auto_ptr_char temp(e.getMsg());
 150         throw EncryptionException(string("XMLSecurity exception while encrypting: ") + temp.get());
 151     }
 152     catch(XSECCryptoException& e) {
 153         throw EncryptionException(string("XMLSecurity exception while encrypting: ") + e.getMsg());
 154     }
 155 }
 156
 157 EncryptedData* Encrypter::encryptElementContent(DOMElement* element, EncryptionParams& encParams, KeyEncryptionParams* kencParams)
 158 {
 159     // We can reuse the cipher object if the document hasn't changed.
 160
 161     if (m_cipher && m_cipher->getDocument()!=element->getOwnerDocument()) {
 162         XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->releaseCipher(m_cipher);
 163         m_cipher=nullptr;
 164     }
 165
 166     if (!m_cipher) {
 167         m_cipher=XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->newCipher(element->getOwnerDocument());
 168         m_cipher->setExclusiveC14nSerialisation(false);
 169     }
 170
 171     try {
 172         checkParams(encParams,kencParams);
 173         m_cipher->encryptElementContentDetached(element, ENCRYPT_NONE, encParams.m_algorithm);
 174         return decorateAndUnmarshall(encParams, kencParams);
 175     }
 176     catch(XSECException& e) {
 177         auto_ptr_char temp(e.getMsg());
 178         throw EncryptionException(string("XMLSecurity exception while encrypting: ") + temp.get());
 179     }
 180     catch(XSECCryptoException& e) {
 181         throw EncryptionException(string("XMLSecurity exception while encrypting: ") + e.getMsg());
 182     }
 183 }
 184
 185 EncryptedData* Encrypter::encryptStream(istream& input, EncryptionParams& encParams, KeyEncryptionParams* kencParams)
 186 {
 187     // Get a fresh cipher object and document.
 188
 189     if (m_cipher) {
 190         XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->releaseCipher(m_cipher);
 191         m_cipher=nullptr;
 192     }
 193
 194     DOMDocument* doc=nullptr;
 195     try {
 196         doc=XMLToolingConfig::getConfig().getParser().newDocument();
 197         XercesJanitor<DOMDocument> janitor(doc);
 198         m_cipher=XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->newCipher(doc);
 199         m_cipher->setExclusiveC14nSerialisation(false);
 200
 201         checkParams(encParams,kencParams);
 202         StreamInputSource::StreamBinInputStream xstream(input);
 203         m_cipher->encryptBinInputStream(&xstream, ENCRYPT_NONE, encParams.m_algorithm);
 204         return decorateAndUnmarshall(encParams, kencParams);
 205     }
 206     catch(XSECException& e) {
 207         auto_ptr_char temp(e.getMsg());
 208         throw EncryptionException(string("XMLSecurity exception while encrypting: ") + temp.get());
 209     }
 210     catch(XSECCryptoException& e) {
 211         throw EncryptionException(string("XMLSecurity exception while encrypting: ") + e.getMsg());
 212     }
 213 }
 214
 215 EncryptedData* Encrypter::decorateAndUnmarshall(EncryptionParams& encParams, KeyEncryptionParams* kencParams)
 216 {
 217     XENCEncryptedData* encData=m_cipher->getEncryptedData();
 218     if (!encData)
 219         throw EncryptionException("No EncryptedData element found?");
 220
 221     // Unmarshall a tooling version of EncryptedData around the DOM.
 222     EncryptedData* xmlEncData=nullptr;
 223     auto_ptr<XMLObject> xmlObject(XMLObjectBuilder::buildOneFromElement(encData->getElement()));
 224     if (!(xmlObject.get()) || !(xmlEncData=dynamic_cast<EncryptedData*>(xmlObject.get())))
 225         throw EncryptionException("Unable to unmarshall into EncryptedData object.");
 226
 227     // Unbind from DOM so we can divorce this from the original document.
 228     xmlEncData->releaseThisAndChildrenDOM();
 229
 230     // KeyInfo?
 231     KeyInfo* kinfo = encParams.m_credential ? encParams.m_credential->getKeyInfo(encParams.m_compact) : nullptr;
 232     if (kinfo)
 233         xmlEncData->setKeyInfo(kinfo);
 234
 235     // Are we doing a key encryption?
 236     if (kencParams) {
 237         XSECCryptoKey* kek = kencParams->m_credential.getPublicKey();
 238         if (!kek)
 239             throw EncryptionException("Credential in KeyEncryptionParams structure did not supply a public key.");
 240         if (!kencParams->m_algorithm)
 241             kencParams->m_algorithm = getKeyTransportAlgorithm(kencParams->m_credential, encParams.m_algorithm);
 242
 243         m_cipher->setKEK(kek->clone());
 244         // ownership of this belongs to us, for some reason...
 245         auto_ptr<XENCEncryptedKey> encKey(
 246             m_cipher->encryptKey(encParams.m_keyBuffer, encParams.m_keyBufferSize, ENCRYPT_NONE, kencParams->m_algorithm)
 247             );
 248         EncryptedKey* xmlEncKey=nullptr;
 249         auto_ptr<XMLObject> xmlObjectKey(XMLObjectBuilder::buildOneFromElement(encKey->getElement()));
 250         if (!(xmlObjectKey.get()) || !(xmlEncKey=dynamic_cast<EncryptedKey*>(xmlObjectKey.get())))
 251             throw EncryptionException("Unable to unmarshall into EncryptedKey object.");
 252
 253         xmlEncKey->releaseThisAndChildrenDOM();
 254
 255         // Recipient?
 256         if (kencParams->m_recipient)
 257             xmlEncKey->setRecipient(kencParams->m_recipient);
 258
 259         // KeyInfo?
 260         kinfo = kencParams->m_credential.getKeyInfo(encParams.m_compact);
 261         if (kinfo)
 262             xmlEncKey->setKeyInfo(kinfo);
 263
 264         // Add the EncryptedKey inline.
 265         if (!xmlEncData->getKeyInfo())
 266             xmlEncData->setKeyInfo(KeyInfoBuilder::buildKeyInfo());
 267         xmlEncData->getKeyInfo()->getUnknownXMLObjects().push_back(xmlEncKey);
 268         xmlObjectKey.release();
 269     }
 270
 271     xmlObject.release();
 272     return xmlEncData;
 273 }
 274
 275 EncryptedKey* Encrypter::encryptKey(
 276     const unsigned char* keyBuffer, unsigned int keyBufferSize, KeyEncryptionParams& kencParams, bool compact
 277     )
 278 {
 279     // Get a fresh cipher object and document.
 280
 281     if (m_cipher) {
 282         XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->releaseCipher(m_cipher);
 283         m_cipher=nullptr;
 284     }
 285
 286     XSECCryptoKey* kek = kencParams.m_credential.getPublicKey();
 287     if (!kek)
 288         throw EncryptionException("Credential in KeyEncryptionParams structure did not supply a public key.");
 289
 290     DOMDocument* doc=nullptr;
 291     try {
 292         doc=XMLToolingConfig::getConfig().getParser().newDocument();
 293         XercesJanitor<DOMDocument> janitor(doc);
 294         m_cipher=XMLToolingInternalConfig::getInternalConfig().m_xsecProvider->newCipher(doc);
 295         m_cipher->setExclusiveC14nSerialisation(false);
 296         m_cipher->setKEK(kek->clone());
 297         auto_ptr<XENCEncryptedKey> encKey(m_cipher->encryptKey(keyBuffer, keyBufferSize, ENCRYPT_NONE, kencParams.m_algorithm));
 298
 299         EncryptedKey* xmlEncKey=nullptr;
 300         auto_ptr<XMLObject> xmlObjectKey(XMLObjectBuilder::buildOneFromElement(encKey->getElement()));
 301         if (!(xmlObjectKey.get()) || !(xmlEncKey=dynamic_cast<EncryptedKey*>(xmlObjectKey.get())))
 302             throw EncryptionException("Unable to unmarshall into EncryptedKey object.");
 303
 304         xmlEncKey->releaseThisAndChildrenDOM();
 305
 306         // Recipient?
 307         if (kencParams.m_recipient)
 308             xmlEncKey->setRecipient(kencParams.m_recipient);
 309
 310         // KeyInfo?
 311         KeyInfo* kinfo = kencParams.m_credential.getKeyInfo(compact);
 312         if (kinfo)
 313             xmlEncKey->setKeyInfo(kinfo);
 314
 315         xmlObjectKey.release();
 316         return xmlEncKey;
 317     }
 318     catch(XSECException& e) {
 319         auto_ptr_char temp(e.getMsg());
 320         throw EncryptionException(string("XMLSecurity exception while encrypting: ") + temp.get());
 321     }
 322     catch(XSECCryptoException& e) {
 323         throw EncryptionException(string("XMLSecurity exception while encrypting: ") + e.getMsg());
 324     }
 325 }
 326
 327 const XMLCh* Encrypter::getKeyTransportAlgorithm(const Credential& credential, const XMLCh* encryptionAlg)
 328 {
 329     const char* alg = credential.getAlgorithm();
 330     if (!alg || !strcmp(alg, "RSA")) {
 331         if (XMLString::equals(encryptionAlg,DSIGConstants::s_unicodeStrURI3DES_CBC))
 332             return DSIGConstants::s_unicodeStrURIRSA_1_5;
 333         else
 334             return DSIGConstants::s_unicodeStrURIRSA_OAEP_MGFP1;
 335     }
 336     else if (!strcmp(alg, "AES")) {
 337         switch (credential.getKeySize()) {
 338             case 128:
 339                 return DSIGConstants::s_unicodeStrURIKW_AES128;
 340             case 192:
 341                 return DSIGConstants::s_unicodeStrURIKW_AES192;
 342             case 256:
 343                 return DSIGConstants::s_unicodeStrURIKW_AES256;
 344         }
 345     }
 346     else if (!strcmp(alg, "DESede")) {
 347         return DSIGConstants::s_unicodeStrURIKW_3DES;
 348     }
 349
 350     return nullptr;
 351 }