4de11d11e8
This commit has the initial ODK library. Partners may use this code to begin integrating the ODK library into their platform. The functionality is not complete, but this should help partners get an early start playing with build files.
91 lines
3.3 KiB
C++
91 lines
3.3 KiB
C++
// Copyright 2019 Google LLC. All Rights Reserved. This file and proprietary
|
|
// source code may only be used and distributed under the Widevine Master
|
|
// License Agreement.
|
|
//
|
|
#ifndef CDM_OEC_KEY_DERIVER_H_
|
|
#define CDM_OEC_KEY_DERIVER_H_
|
|
|
|
#include <openssl/aes.h>
|
|
#include <openssl/rsa.h>
|
|
#include <time.h>
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
#include "oec_device_features.h"
|
|
#include "oemcrypto_types.h"
|
|
#include "pst_report.h"
|
|
|
|
namespace wvoec {
|
|
|
|
constexpr size_t kMaxTestRSAKeyLength = 2000; // Rough estimate.
|
|
|
|
// This structure will be signed to simulate a provisioning response from the
|
|
// server.
|
|
struct RSAPrivateKeyMessage {
|
|
uint8_t rsa_key[kMaxTestRSAKeyLength];
|
|
uint8_t rsa_key_iv[KEY_IV_SIZE];
|
|
size_t rsa_key_length;
|
|
uint32_t nonce;
|
|
};
|
|
|
|
// Holds an encryption key and can encrypt a provisioning message. It also can
|
|
// encrypt short buffers using CBC, such as content keys in a license.
|
|
class Encryptor {
|
|
public:
|
|
Encryptor() : enc_key_(KEY_SIZE, 0) {}
|
|
Encryptor(const std::vector<uint8_t>& enc_key) { set_enc_key(enc_key); };
|
|
Encryptor& operator=(const Encryptor&) = default;
|
|
void set_enc_key(const std::vector<uint8_t>& enc_key);
|
|
|
|
// This encrypts an RSAPrivateKeyMessage with encryption_key so that it may be
|
|
// loaded with OEMCrypto_RewrapDeviceRSAKey.
|
|
// This modifies the clear data: it adds padding and generates a random iv.
|
|
void PadAndEncryptProvisioningMessage(RSAPrivateKeyMessage* data,
|
|
RSAPrivateKeyMessage* encrypted) const;
|
|
|
|
void CBCEncrypt(const uint8_t* data, uint8_t* encrypted_data,
|
|
size_t data_length, const uint8_t (&iv)[KEY_IV_SIZE]) const;
|
|
|
|
private:
|
|
std::vector<uint8_t> enc_key_;
|
|
};
|
|
|
|
// Holds encryption and mac keys derived from a master key.
|
|
// Can be used to sign a buffer as either a server or client.
|
|
class KeyDeriver : public Encryptor {
|
|
public:
|
|
KeyDeriver()
|
|
: mac_key_server_(MAC_KEY_SIZE, 0), mac_key_client_(MAC_KEY_SIZE, 0) {}
|
|
KeyDeriver& operator=(const KeyDeriver&) = default;
|
|
|
|
// Generate mac and enc keys give the master key.
|
|
void DeriveKeys(const uint8_t* master_key,
|
|
const std::vector<uint8_t>& mac_key_context,
|
|
const std::vector<uint8_t>& enc_key_context);
|
|
// Sign the buffer with server's mac key.
|
|
void ServerSignBuffer(const uint8_t* data, size_t data_length,
|
|
std::vector<uint8_t>* signature);
|
|
// Sign the buffer with client's known mac key. Known test keys must be
|
|
// installed first. This uses HMAC with SHA256, so is suitable for a message.
|
|
void ClientSignBuffer(const std::vector<uint8_t>& buffer,
|
|
std::vector<uint8_t>* signature);
|
|
// Sign the pst buffer with client's known mac key. Known test keys must be
|
|
// installed first. This uses HMAC with SHA128, and skips the beginning of the
|
|
// buffer, so is only suitable for a pst report.
|
|
void ClientSignPstReport(const std::vector<uint8_t>& pst_report_buffer,
|
|
std::vector<uint8_t>* signature);
|
|
void set_mac_keys(const uint8_t* mac_keys);
|
|
|
|
private:
|
|
// Internal utility function to derive key using CMAC-128
|
|
void DeriveKey(const uint8_t* key, const std::vector<uint8_t>& context,
|
|
int counter, std::vector<uint8_t>* out);
|
|
|
|
std::vector<uint8_t> mac_key_server_;
|
|
std::vector<uint8_t> mac_key_client_;
|
|
};
|
|
|
|
} // namespace wvoec
|
|
|
|
#endif // CDM_OEC_KEY_DERIVER_H_
|