Files
android/libwvdrmengine/cdm/core/include/crypto_session.h
Rahul Frias a74980b2f1 Address key selection and decryption concurrency issues
Decryption calls though multiple threads may result in race conditions
between the setting of the key and the actual call to decryption.
This results in OEMCrypto errors when the buffer type used in
decryption did not match the key selected. This is addressed by
having the the two calls be in the same critical section.

b/11009857

Change-Id: I74f1a0689ca17114f3cdd029022013b05c415acd
2013-10-02 15:44:39 -07:00

103 lines
3.4 KiB
C++

// Copyright 2012 Google Inc. All Rights Reserved.
//
// OEMCrypto Client - wrapper class for C-style OEMCrypto interface
//
#ifndef CDM_BASE_CRYPTO_SESSSION_H_
#define CDM_BASE_CRYPTO_SESSSION_H_
#include <string>
#include <map>
#include "lock.h"
#include "oemcrypto_adapter.h"
#include "OEMCryptoCENC.h"
#include "wv_cdm_types.h"
namespace wvcdm {
class CryptoKey;
typedef std::map<CryptoKeyId, CryptoKey*> CryptoKeyMap;
class CryptoSession {
public:
CryptoSession();
~CryptoSession();
bool ValidateKeybox();
bool GetToken(std::string* token);
CdmSecurityLevel GetSecurityLevel();
bool GetDeviceUniqueId(std::string* device_id);
bool GetSystemId(uint32_t* system_id);
bool GetProvisioningId(std::string* provisioning_id);
CdmResponseType Open() { return Open(kLevelDefault); }
CdmResponseType Open(SecurityLevel requested_security_level);
void Close();
bool IsOpen() { return open_; }
CryptoSessionId oec_session_id() { return oec_session_id_; }
// Key request/response
void GenerateRequestId(std::string& req_id_str);
bool PrepareRequest(const std::string& key_deriv_message,
bool is_provisioning, std::string* signature);
bool PrepareRenewalRequest(const std::string& message,
std::string* signature);
CdmResponseType LoadKeys(const std::string& message,
const std::string& signature,
const std::string& mac_key_iv,
const std::string& mac_key,
int num_keys, const CryptoKey* key_array);
bool LoadCertificatePrivateKey(std::string& wrapped_key);
bool RefreshKeys(const std::string& message, const std::string& signature,
int num_keys, const CryptoKey* key_array);
bool GenerateNonce(uint32_t* nonce);
bool GenerateDerivedKeys(const std::string& message);
bool GenerateDerivedKeys(const std::string& message,
const std::string& session_key);
bool RewrapDeviceRSAKey(const std::string& message,
const std::string& signature,
const std::string& nonce,
const std::string& enc_rsa_key,
const std::string& rsa_key_iv,
std::string* wrapped_rsa_key);
// Media data path
bool SelectKey(const std::string& key_id);
CdmResponseType Decrypt(const CdmDecryptionParameters& parameters);
bool GetRandom(size_t data_length, uint8_t* random_data);
private:
void Init();
void Terminate();
void GenerateMacContext(const std::string& input_context,
std::string* deriv_context);
void GenerateEncryptContext(const std::string& input_context,
std::string* deriv_context);
bool GenerateSignature(const std::string& message, bool use_rsa,
std::string* signature);
size_t GetOffset(std::string message, std::string field);
bool SetDestinationBufferType();
static const size_t kSignatureSize = 32; // size for HMAC-SHA256 signature
static Lock crypto_lock_;
static bool initialized_;
static int session_count_;
bool open_;
CryptoSessionId oec_session_id_;
OEMCryptoBufferType destination_buffer_type_;
bool is_destination_buffer_type_valid_;
SecurityLevel requested_security_level_;
KeyId key_id_;
CORE_DISALLOW_COPY_AND_ASSIGN(CryptoSession);
};
}; // namespace wvcdm
#endif // CDM_BASE_CRYPTO_SESSSION_H_