Files
android/libwvdrmengine/cdm/core/src/crypto_session.cpp
Jeff Tinker d601914d57 Don't set BufferType to clear for non-encrypted buffers
When non-encrypted buffers are sent to OEMCrypto_DecryptCTR,
the cdm is overriding the buffer type to be non-secure.  This
is incorrect, the encrypted state is not the same as the buffer
protection level.

This change removes the special case override that should not
be there.

bug: 8621521
Change-Id: I705b1dc82b393305b9e6bdcb524d6b8126f58d3d
2013-04-18 18:23:21 -07:00

512 lines
16 KiB
C++
Executable File

// Copyright 2012 Google Inc. All Rights Reserved.
//
// Crypto - wrapper classes for OEMCrypto interface
//
#include "crypto_session.h"
#include <iostream>
#include "crypto_engine.h"
#include "log.h"
// TODO(gmorgan,jtinker): decide if OEMCryptoCENC is needed here.
#include "OEMCryptoCENC.h"
#include "properties.h"
#include "string_conversions.h"
#include "wv_cdm_constants.h"
namespace {
// Encode unsigned integer into a big endian formatted string
std::string EncodeUint32(unsigned int u) {
std::string s;
s.append(1, (u >> 24) & 0xFF);
s.append(1, (u >> 16) & 0xFF);
s.append(1, (u >> 8) & 0xFF);
s.append(1, (u >> 0) & 0xFF);
return s;
}
}
namespace wvcdm {
// wrapper classes for OEMCrypto interface
// CryptoEngine -- top-level interface
// CryptoSession -- session-specific interface
// CryptoKey -- key interface
// CryptoSession methods
CryptoSession::CryptoSession() :
valid_(false),
open_(false),
is_destination_buffer_type_valid_(false) {}
CryptoSession::CryptoSession(const std::string& sname) :
valid_(true),
open_(false),
cdm_session_id_(sname),
is_destination_buffer_type_valid_(false) {}
CryptoSession::~CryptoSession() {
if (open_) {
Close();
}
LOGV("CryptoSession::dtor: SLock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
crypto_engine->sessions_.erase(cdm_session_id_);
if (0 == crypto_engine->sessions_.size()) {
crypto_engine->DeleteInstance();
}
CryptoKeyMap::iterator i(keys_.begin());
for (; i != keys_.end(); ++i)
delete i->second;
keys_.clear();
}
bool CryptoSession::Open() {
LOGV("CryptoSession::Open: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
OEMCrypto_SESSION sid;
OEMCryptoResult sts;
if (open_)
return false;
sts = OEMCrypto_OpenSession(&sid);
if (OEMCrypto_SUCCESS != sts) {
open_ = false;
} else {
oec_session_id_ = static_cast<CryptoSessionId>(sid);
LOGV("OpenSession: id= %ld", (uint32_t) oec_session_id_);
open_ = true;
}
return open_;
}
void CryptoSession::Close() {
LOGV("CryptoSession::Close: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
LOGV("CloseSession: id=%ld open=%s", (uint32_t) oec_session_id_, open_? "true" : "false") ;
if (open_) {
OEMCryptoResult sts = OEMCrypto_CloseSession(oec_session_id_);
if (OEMCrypto_SUCCESS == sts) {
open_ = false;
}
}
}
void CryptoSession::GenerateRequestId(std::string& req_id_str) {
LOGV("CryptoSession::GenerateRequestId: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
// TODO(gmorgan): Get unique ID from OEMCrypto
req_id_str.assign("987654321");
}
bool CryptoSession::PrepareRequest(const std::string& message,
std::string* signature) {
LOGV("CryptoSession::PrepareRequest: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
if (!signature) {
LOGE("CryptoSession::PrepareRequest : No output destination provided.");
return false;
}
OEMCryptoResult sts;
if (!Properties::use_certificates_as_identification()) {
if (!GenerateDerivedKeys(message)) {
return false;
}
}
if (!GenerateSignature(message, signature)) {
return false;
}
return true;
}
bool CryptoSession::PrepareRenewalRequest(const std::string& message,
std::string* signature) {
LOGV("CryptoSession::PrepareRenewalRequest: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
if (!signature) {
LOGE("CryptoSession::PrepareRenewalRequest : No output destination provided.");
return false;
}
if (!GenerateSignature(message, signature)) {
return false;
}
return true;
}
void CryptoSession::GenerateMacContext(const std::string& input_context,
std::string* deriv_context) {
if (!deriv_context) {
LOGE("CryptoSession::GenerateMacContext : No output destination provided.");
return;
}
const std::string kSigningKeyLabel = "AUTHENTICATION";
const size_t kSigningKeySizeBits = MAC_KEY_SIZE * 8;
deriv_context->assign(kSigningKeyLabel);
deriv_context->append(1, '\0');
deriv_context->append(input_context);
deriv_context->append(EncodeUint32(kSigningKeySizeBits));
}
void CryptoSession::GenerateEncryptContext(const std::string& input_context,
std::string* deriv_context) {
if (!deriv_context) {
LOGE("CryptoSession::GenerateEncryptContext : No output destination provided.");
return;
}
const std::string kEncryptionKeyLabel = "ENCRYPTION";
const size_t kEncryptionKeySizeBits = KEY_SIZE * 8;
deriv_context->assign(kEncryptionKeyLabel);
deriv_context->append(1, '\0');
deriv_context->append(input_context);
deriv_context->append(EncodeUint32(kEncryptionKeySizeBits));
}
size_t CryptoSession::GetOffset(std::string message, std::string field) {
size_t pos = message.find(field);
if (pos == std::string::npos) {
LOGE("CryptoSession::GetOffset : Cannot find offset for %s", field.c_str());
pos = 0;
}
return pos;
}
bool CryptoSession::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) {
LOGV("CryptoSession::LoadKeys: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
const uint8_t* msg = reinterpret_cast<const uint8_t*>(message.data());
const uint8_t* enc_mac_key = NULL;
const uint8_t* enc_mac_key_iv = NULL;
if (mac_key.size() >= MAC_KEY_SIZE && mac_key_iv.size() >= KEY_IV_SIZE) {
enc_mac_key = msg + GetOffset(message, mac_key);
enc_mac_key_iv = msg + GetOffset(message, mac_key_iv);
}
std::vector<OEMCrypto_KeyObject> load_key_array(num_keys);
for (int i=0; i<num_keys; ++i) {
const CryptoKey* ki = &key_array[i];
OEMCrypto_KeyObject* ko = &load_key_array[i];
ko->key_id = msg + GetOffset(message, ki->key_id());
ko->key_id_length = ki->key_id().length();
ko->key_data_iv = msg + GetOffset(message, ki->key_data_iv());
ko->key_data = msg + GetOffset(message, ki->key_data());
ko->key_data_length = ki->key_data().length();
if (ki->HasKeyControl()) {
ko->key_control_iv = msg + GetOffset(message, ki->key_control_iv());
ko->key_control = msg + GetOffset(message, ki->key_control());
}
else {
LOGE("For key %d: XXX key has no control block. size=%d", i, ki->key_control().size());
ko->key_control_iv = NULL;
ko->key_control = NULL;
}
}
LOGV("LoadKeys: id=%ld", (uint32_t) oec_session_id_);
return (OEMCrypto_SUCCESS == OEMCrypto_LoadKeys(
oec_session_id_, msg, message.size(),
reinterpret_cast<const uint8_t*>(signature.data()),
signature.size(), enc_mac_key_iv, enc_mac_key,
num_keys, &load_key_array[0]));
}
bool CryptoSession::LoadCertificatePrivateKey(std::string& wrapped_key) {
LOGV("CryptoSession::LoadKeys: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
LOGV("LoadDeviceRSAKey: id=%ld", (uint32_t) oec_session_id_);
OEMCryptoResult sts = OEMCrypto_LoadDeviceRSAKey(
oec_session_id_,
reinterpret_cast<const uint8_t*>(wrapped_key.data()),
wrapped_key.size());
if (OEMCrypto_SUCCESS != sts) {
LOGD("LoadCertificatePrivateKey: OEMCrypto_LoadDeviceRSAKey error=%d", sts);
return false;
}
return true;
}
bool CryptoSession::RefreshKeys(const std::string& message,
const std::string& signature,
int num_keys,
const CryptoKey* key_array) {
LOGV("CryptoSession::RefreshKeys: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
const uint8_t* msg = reinterpret_cast<const uint8_t*>(message.data());
std::vector<OEMCrypto_KeyRefreshObject> load_key_array(num_keys);
for (int i=0; i<num_keys; ++i) {
const CryptoKey* ki = &key_array[i];
OEMCrypto_KeyRefreshObject* ko = &load_key_array[i];
if (ki->key_id().empty()) {
ko->key_id = NULL;
} else {
ko->key_id = msg + GetOffset(message, ki->key_id());
}
if (ki->HasKeyControl()) {
if (ki->key_control_iv().empty()) {
ko->key_control_iv = NULL;
} else {
ko->key_control_iv = msg + GetOffset(message, ki->key_control_iv());
}
ko->key_control = msg + GetOffset(message, ki->key_control());
}
else {
ko->key_control_iv = NULL;
ko->key_control = NULL;
}
}
LOGV("RefreshKeys: id=%ld", static_cast<uint32_t>(oec_session_id_));
return (OEMCrypto_SUCCESS == OEMCrypto_RefreshKeys(
oec_session_id_, msg, message.size(),
reinterpret_cast<const uint8_t*>(signature.data()),
signature.size(),
num_keys, &load_key_array[0]));
}
bool CryptoSession::SelectKey(const std::string& key_id) {
LOGV("CryptoSession::SelectKey: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
const uint8_t* key_id_string =
reinterpret_cast<const uint8_t*>(key_id.data());
LOGV("SelectKey: id=%ld", static_cast<uint32_t>(oec_session_id_));
OEMCryptoResult sts = OEMCrypto_SelectKey(oec_session_id_, key_id_string,
key_id.size());
if (OEMCrypto_SUCCESS != sts) {
return false;
}
return true;
}
bool CryptoSession::GenerateDerivedKeys(const std::string& message) {
std::string mac_deriv_message;
std::string enc_deriv_message;
GenerateMacContext(message, &mac_deriv_message);
GenerateEncryptContext(message, &enc_deriv_message);
LOGV("GenerateDerivedKeys: id=%ld", (uint32_t) oec_session_id_);
OEMCryptoResult sts = OEMCrypto_GenerateDerivedKeys(
oec_session_id_,
reinterpret_cast<const uint8_t*>(mac_deriv_message.data()),
mac_deriv_message.size(),
reinterpret_cast<const uint8_t*>(enc_deriv_message.data()),
enc_deriv_message.size());
if (OEMCrypto_SUCCESS != sts) {
LOGD("GenerateDerivedKeys: OEMCrypto_GenerateDerivedKeys error=%d", sts);
return false;
}
return true;
}
bool CryptoSession::GenerateDerivedKeys(const std::string& message,
const std::string& session_key) {
std::string mac_deriv_message;
std::string enc_deriv_message;
GenerateMacContext(message, &mac_deriv_message);
GenerateEncryptContext(message, &enc_deriv_message);
LOGV("GenerateDerivedKeys: id=%ld", (uint32_t) oec_session_id_);
OEMCryptoResult sts = OEMCrypto_DeriveKeysFromSessionKey(
oec_session_id_,
reinterpret_cast<const uint8_t*>(session_key.data()),
session_key.size(),
reinterpret_cast<const uint8_t*>(mac_deriv_message.data()),
mac_deriv_message.size(),
reinterpret_cast<const uint8_t*>(enc_deriv_message.data()),
enc_deriv_message.size());
if (OEMCrypto_SUCCESS != sts) {
LOGD("GenerateDerivedKeys: OEMCrypto_DeriveKeysFromSessionKey err=%d", sts);
return false;
}
return true;
}
bool CryptoSession::GenerateSignature(const std::string& message,
std::string* signature) {
LOGV("GenerateSignature: id=%ld", (uint32_t) oec_session_id_);
uint8_t signature_buf[32];
uint32_t length = 32;
OEMCryptoResult sts;
if (Properties::use_certificates_as_identification()) {
sts = OEMCrypto_GenerateRSASignature(
oec_session_id_,
reinterpret_cast<const uint8_t*>(message.data()),
message.size(),
signature_buf,
&length);
}
else {
sts = OEMCrypto_GenerateSignature(
oec_session_id_,
reinterpret_cast<const uint8_t*>(message.data()),
message.size(),
signature_buf,
&length);
}
if (OEMCrypto_SUCCESS != sts) {
LOGD("GenerateSignature: OEMCrypto_GenerateSignature err=%d", sts);
return false;
}
signature->assign(reinterpret_cast<const char*>(signature_buf), length);
return true;
}
CdmResponseType CryptoSession::Decrypt(bool is_encrypted,
const uint8_t* encrypt_buffer,
size_t encrypt_length,
const std::vector<uint8_t>& iv,
size_t block_offset,
void* decrypt_buffer,
bool is_video) {
if (!is_destination_buffer_type_valid_) {
if (!SetDestinationBufferType())
return UNKNOWN_ERROR;
}
OEMCrypto_DestBufferDesc buffer_descriptor;
buffer_descriptor.type = destination_buffer_type_;
switch (buffer_descriptor.type) {
case OEMCrypto_BufferType_Clear:
buffer_descriptor.buffer.clear.address =
static_cast<uint8_t*>(decrypt_buffer);
buffer_descriptor.buffer.clear.max_length = encrypt_length;
break;
case OEMCrypto_BufferType_Secure:
buffer_descriptor.buffer.secure.handle = decrypt_buffer;
buffer_descriptor.buffer.secure.max_length = encrypt_length;
break;
case OEMCrypto_BufferType_Direct:
buffer_descriptor.type = OEMCrypto_BufferType_Direct;
buffer_descriptor.buffer.direct.is_video = is_video;
break;
}
OEMCryptoResult sts = OEMCrypto_DecryptCTR(oec_session_id_, encrypt_buffer,
encrypt_length, is_encrypted,
&iv[0], block_offset,
&buffer_descriptor);
if (OEMCrypto_SUCCESS != sts) {
return UNKNOWN_ERROR;
}
return NO_ERROR;
}
bool CryptoSession::GenerateNonce(uint32_t* nonce) {
if (!nonce) {
LOGE("input parameter is null");
return false;
}
LOGV("CryptoSession::GenerateNonce: Lock");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
return(OEMCrypto_SUCCESS == OEMCrypto_GenerateNonce(oec_session_id_, nonce));
}
bool CryptoSession::SetDestinationBufferType() {
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
if (Properties::oem_crypto_use_secure_buffers()) {
if (crypto_engine->GetSecurityLevel() == CryptoEngine::kSecurityLevelL1) {
destination_buffer_type_ = OEMCrypto_BufferType_Secure;
}
else {
destination_buffer_type_ = OEMCrypto_BufferType_Clear;
}
}
else if (Properties::oem_crypto_use_fifo()) {
destination_buffer_type_ = OEMCrypto_BufferType_Direct;
}
else if (Properties::oem_crypto_use_userspace_buffers()) {
destination_buffer_type_ = OEMCrypto_BufferType_Clear;
}
else {
return false;
}
is_destination_buffer_type_valid_ = true;
return true;
}
bool CryptoSession::RewrapDeviceRSAKey(const std::string& message,
const uint32_t* nonce,
const uint8_t* enc_rsa_key,
size_t enc_rsa_key_length,
const uint8_t* enc_rsa_key_iv,
uint8_t* wrapped_rsa_key,
size_t* wrapped_rsa_key_length) {
LOGV("CryptoSession::RewrapDeviceRSAKey: Lock+++");
CryptoEngine* crypto_engine = CryptoEngine::GetInstance();
AutoLock auto_lock(crypto_engine->crypto_lock_);
LOGV("crypto session id=%ld", static_cast<uint32_t>(oec_session_id_));
// HMAC-SHA256 signature
uint8_t signature[kSignatureSize];
size_t signature_length = kSignatureSize;
OEMCryptoResult status = OEMCrypto_GenerateSignature(
oec_session_id_,
reinterpret_cast<const uint8_t*>(message.data()),
message.size(),
signature,
&signature_length);
if (OEMCrypto_SUCCESS != status) {
LOGE("CryptoSession::RewrapDeviceRSAKey: GenerateSiganture failed");
return false;
}
status = OEMCrypto_RewrapDeviceRSAKey(
oec_session_id_,
reinterpret_cast<const uint8_t*>(message.data()), message.length(),
signature, signature_length,
nonce,
enc_rsa_key, enc_rsa_key_length,
enc_rsa_key_iv,
wrapped_rsa_key,
wrapped_rsa_key_length);
if (OEMCrypto_SUCCESS != status) {
return false;
}
return true;
}
}; // namespace wvcdm