118 lines
3.6 KiB
C++
118 lines
3.6 KiB
C++
//
|
|
// Copyright (C) 2012 The Android Open Source Project
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
//
|
|
|
|
#include "shill/crypto_des_cbc.h"
|
|
|
|
#include <rpc/des_crypt.h>
|
|
|
|
#include <base/files/file_util.h>
|
|
#include <base/strings/string_util.h>
|
|
#include <brillo/data_encoding.h>
|
|
|
|
using base::FilePath;
|
|
using std::string;
|
|
using std::vector;
|
|
|
|
namespace shill {
|
|
|
|
const unsigned int CryptoDESCBC::kBlockSize = 8;
|
|
const char CryptoDESCBC::kID[] = "des-cbc";
|
|
const char CryptoDESCBC::kSentinel[] = "[ok]";
|
|
const char CryptoDESCBC::kVersion2Prefix[] = "02:";
|
|
|
|
CryptoDESCBC::CryptoDESCBC() {}
|
|
|
|
string CryptoDESCBC::GetID() {
|
|
return kID;
|
|
}
|
|
|
|
bool CryptoDESCBC::Encrypt(const string& plaintext, string* ciphertext) {
|
|
// Never encrypt. We'll fall back to rot47 which doesn't depend on
|
|
// the owner key which may change due to rotation.
|
|
return false;
|
|
}
|
|
|
|
bool CryptoDESCBC::Decrypt(const string& ciphertext, string* plaintext) {
|
|
CHECK_EQ(kBlockSize, key_.size());
|
|
CHECK_EQ(kBlockSize, iv_.size());
|
|
int version = 1;
|
|
string b64_ciphertext = ciphertext;
|
|
if (base::StartsWith(ciphertext, kVersion2Prefix,
|
|
base::CompareCase::SENSITIVE)) {
|
|
version = 2;
|
|
b64_ciphertext.erase(0, strlen(kVersion2Prefix));
|
|
}
|
|
|
|
string decoded_data;
|
|
if (!brillo::data_encoding::Base64Decode(b64_ciphertext, &decoded_data)) {
|
|
LOG(ERROR) << "Unable to base64-decode DEC-CBC ciphertext.";
|
|
return false;
|
|
}
|
|
|
|
vector<char> data(decoded_data.c_str(),
|
|
decoded_data.c_str() + decoded_data.length());
|
|
if (data.empty() || (data.size() % kBlockSize != 0)) {
|
|
LOG(ERROR) << "Invalid DES-CBC ciphertext size: " << data.size();
|
|
return false;
|
|
}
|
|
|
|
// The IV is modified in place.
|
|
vector<char> iv = iv_;
|
|
int rv =
|
|
cbc_crypt(key_.data(), data.data(), data.size(), DES_DECRYPT, iv.data());
|
|
if (DES_FAILED(rv)) {
|
|
LOG(ERROR) << "DES-CBC decryption failed.";
|
|
return false;
|
|
}
|
|
if (data.back() != '\0') {
|
|
LOG(ERROR) << "DEC-CBC decryption resulted in invalid plain text.";
|
|
return false;
|
|
}
|
|
string text = data.data();
|
|
if (version == 2) {
|
|
if (!base::EndsWith(text, kSentinel, base::CompareCase::SENSITIVE)) {
|
|
LOG(ERROR) << "DES-CBC decrypted text missing sentinel -- bad key?";
|
|
return false;
|
|
}
|
|
text.erase(text.size() - strlen(kSentinel), strlen(kSentinel));
|
|
}
|
|
*plaintext = text;
|
|
return true;
|
|
}
|
|
|
|
bool CryptoDESCBC::LoadKeyMatter(const FilePath& path) {
|
|
key_.clear();
|
|
iv_.clear();
|
|
string matter;
|
|
// TODO(petkov): This mimics current flimflam behavior. Fix it so that it
|
|
// doesn't read the whole file.
|
|
if (!base::ReadFileToString(path, &matter)) {
|
|
LOG(ERROR) << "Unable to load key matter from " << path.value();
|
|
return false;
|
|
}
|
|
if (matter.size() < 2 * kBlockSize) {
|
|
LOG(ERROR) << "Key matter data not enough " << matter.size() << " < "
|
|
<< 2 * kBlockSize;
|
|
return false;
|
|
}
|
|
string::const_iterator matter_start =
|
|
matter.begin() + (matter.size() - 2 * kBlockSize);
|
|
key_.assign(matter_start + kBlockSize, matter_start + 2 * kBlockSize);
|
|
iv_.assign(matter_start, matter_start + kBlockSize);
|
|
return true;
|
|
}
|
|
|
|
} // namespace shill
|