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8aec8fe0bdcaacb1d3d5e30cc8e41ff649ec7b45
android/libwvdrmengine/oemcrypto/mock/src/oemcrypto_engine_mock.cpp
Fred Gylys-Colwell 6bac5bc50d Clean comments, namespace, and variable names 
This CL removes TODOs and email addresses from comments, unifies some
namespaces and cleans a few variable names.  It is a copy of multiple
CLs on the widevine side.

Change-Id: I1bb649096476a5001a56d746427399de6a88ff69
2014-05-16 15:53:12 -07:00

1180 lines
39 KiB
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// Copyright 2013 Google Inc. All Rights Reserved.
//
// Mock implementation of OEMCrypto APIs
//
#include "oemcrypto_engine_mock.h"
#include <arpa/inet.h>
#include <iostream>
#include <vector>
#include <string.h>
#include "log.h"
#include "oemcrypto_key_mock.h"
#include "oemcrypto_usage_table_mock.h"
#include "openssl/aes.h"
#include "openssl/bio.h"
#include "openssl/cmac.h"
#include "openssl/err.h"
#include "openssl/evp.h"
#include "openssl/hmac.h"
#include "openssl/rand.h"
#include <openssl/rsa.h>
#include "openssl/sha.h"
#include "openssl/x509.h"
#include "string_conversions.h"
#include "wv_cdm_constants.h"
static const int kPssSaltLength = 20;
namespace {
// Increment counter for AES-CTR. The CENC spec specifies we increment only
// the low 64 bits of the IV counter, and leave the high 64 bits alone.
void ctr128_inc64(uint8_t* counter) {
uint32_t n = 16;
do {
if (++counter[--n] != 0) return;
} while (n>8);
}
void dump_openssl_error() {
while (unsigned long err = ERR_get_error()) {
char buffer[120];
LOGE("openssl error -- %lu -- %s",
err, ERR_error_string(err, buffer));
}
}
}
namespace wvoec_mock {
SessionKeyTable::~SessionKeyTable() {
for (KeyMap::iterator i = keys_.begin(); i != keys_.end(); ++i) {
if (NULL != i->second) {
delete i->second;
}
}
}
bool SessionKeyTable::Insert(const KeyId key_id, const Key& key_data) {
if (keys_.find(key_id) != keys_.end()) return false;
keys_[key_id] = new Key(key_data);
return true;
}
Key* SessionKeyTable::Find(const KeyId key_id) {
if (keys_.find(key_id) == keys_.end()) {
return NULL;
}
return keys_[key_id];
}
void SessionKeyTable::Remove(const KeyId key_id) {
if (keys_.find(key_id) != keys_.end()) {
delete keys_[key_id];
keys_.erase(key_id);
}
}
void SessionKeyTable::UpdateDuration(const KeyControlBlock& control) {
for(KeyMap::iterator it = keys_.begin(); it != keys_.end(); ++it) {
it->second->UpdateDuration(control);
}
}
SessionContext::~SessionContext() {
if (usage_entry_) usage_entry_->set_session(NULL);
}
// Internal utility function to derive key using CMAC-128
bool SessionContext::DeriveKey(const std::vector<uint8_t>& key,
const std::vector<uint8_t>& context,
int counter,
std::vector<uint8_t>* out) {
if (key.empty() || counter > 4 || context.empty() || out == NULL) {
LOGE("[DeriveKey(): OEMCrypto_ERROR_INVALID_CONTEXT]");
return false;
}
const EVP_CIPHER* cipher = EVP_aes_128_cbc();
CMAC_CTX* cmac_ctx = CMAC_CTX_new();
if (!CMAC_Init(cmac_ctx, &key[0], key.size(), cipher, 0)) {
LOGE("[DeriveKey(): OEMCrypto_ERROR_CMAC_FAILURE]");
return false;
}
std::vector<uint8_t> message;
message.push_back(counter);
message.insert(message.end(), context.begin(), context.end());
if (!CMAC_Update(cmac_ctx, &message[0], message.size())) {
LOGE("[DeriveKey(): OEMCrypto_ERROR_CMAC_FAILURE]");
return false;
}
size_t reslen;
uint8_t res[128];
if (!CMAC_Final(cmac_ctx, res, &reslen)) {
LOGE("[DeriveKey(): OEMCrypto_ERROR_CMAC_FAILURE]");
return false;
}
out->assign(res, res + reslen);
CMAC_CTX_free(cmac_ctx);
return true;
}
bool SessionContext::DeriveKeys(const std::vector<uint8_t>& master_key,
const std::vector<uint8_t>& mac_key_context,
const std::vector<uint8_t>& enc_key_context) {
// Generate derived key for mac key
std::vector<uint8_t> mac_key_server;
std::vector<uint8_t> mac_key_client;
std::vector<uint8_t> mac_key_part2;
if (!DeriveKey(master_key, mac_key_context, 1, &mac_key_server)) {
return false;
}
if (!DeriveKey(master_key, mac_key_context, 2, &mac_key_part2)) {
return false;
}
mac_key_server.insert(mac_key_server.end(), mac_key_part2.begin(),
mac_key_part2.end());
if (!DeriveKey(master_key, mac_key_context, 3, &mac_key_client)) {
return false;
}
if (!DeriveKey(master_key, mac_key_context, 4, &mac_key_part2)) {
return false;
}
mac_key_client.insert(mac_key_client.end(), mac_key_part2.begin(),
mac_key_part2.end());
// Generate derived key for encryption key
std::vector<uint8_t> enc_key;
if (!DeriveKey(master_key, enc_key_context, 1, &enc_key)) {
return false;
}
#if 0 // Print Derived Keys to stdout.
std::cout << " mac_key_context = " << wvcdm::b2a_hex(mac_key_context)
<< std::endl;
std::cout << " enc_key_context = " << wvcdm::b2a_hex(enc_key_context)
<< std::endl;
std::cout << " mac_key_server = " << wvcdm::b2a_hex(mac_key_server)
<< std::endl;
std::cout << " mac_key_client = " << wvcdm::b2a_hex(mac_key_client)
<< std::endl;
std::cout << " enc_key = " << wvcdm::b2a_hex(enc_key) << std::endl;
#endif
set_mac_key_server(mac_key_server);
set_mac_key_client(mac_key_client);
set_encryption_key(enc_key);
return true;
}
bool SessionContext::RSADeriveKeys(const std::vector<uint8_t>& enc_session_key,
const std::vector<uint8_t>& mac_key_context,
const std::vector<uint8_t>& enc_key_context) {
if (!rsa_key_) {
LOGE("[RSADeriveKeys(): no RSA key set]");
return false;
}
if (enc_session_key.size() != static_cast<size_t>(RSA_size(rsa_key_))) {
LOGE("[RSADeriveKeys(): encrypted session key is wrong size:%zu, should be %d]",
enc_session_key.size(), RSA_size(rsa_key_));
dump_openssl_error();
return false;
}
session_key_.resize(RSA_size(rsa_key_));
int decrypted_size = RSA_private_decrypt(enc_session_key.size(),
&enc_session_key[0],
&session_key_[0], rsa_key_,
RSA_PKCS1_OAEP_PADDING);
if (-1 == decrypted_size) {
LOGE("[RSADeriveKeys(): error decrypting session key.]");
dump_openssl_error();
return false;
}
session_key_.resize(decrypted_size);
if (decrypted_size != static_cast<int>(wvcdm::KEY_SIZE)) {
LOGE("[RSADeriveKeys(): error. session key is wrong size: %d.]",
decrypted_size);
dump_openssl_error();
session_key_.clear();
return false;
}
return DeriveKeys(session_key_, mac_key_context, enc_key_context);
}
// Utility function to generate a message signature
bool SessionContext::GenerateSignature(const uint8_t* message,
size_t message_length,
uint8_t* signature,
size_t* signature_length) {
if (message == NULL || message_length == 0 ||
signature == NULL || signature_length == 0) {
LOGE("[OEMCrypto_GenerateSignature(): OEMCrypto_ERROR_INVALID_CONTEXT]");
return false;
}
if (mac_key_client_.empty() ||
mac_key_client_.size() != wvcdm::MAC_KEY_SIZE) {
LOGE("[GenerateSignature(): No MAC Key]");
return false;
}
if (*signature_length < SHA256_DIGEST_LENGTH) {
*signature_length = SHA256_DIGEST_LENGTH;
return false;
}
unsigned int md_len = *signature_length;
if (HMAC(EVP_sha256(), &mac_key_client_[0], mac_key_client_.size(),
message, message_length, signature, &md_len)) {
*signature_length = md_len;
return true;
}
return false;
}
size_t SessionContext::RSASignatureSize() {
if (!rsa_key_) {
LOGE("[GenerateRSASignature(): no RSA key set]");
return 0;
}
return static_cast<size_t>(RSA_size(rsa_key_));
}
bool SessionContext::GenerateRSASignature(const uint8_t* message,
size_t message_length,
uint8_t* signature,
size_t* signature_length,
RSA_Padding_Scheme padding_scheme) {
if (message == NULL || message_length == 0 ||
signature == NULL || signature_length == 0) {
LOGE("[GenerateRSASignature(): OEMCrypto_ERROR_INVALID_CONTEXT]");
return false;
}
if (!rsa_key_) {
LOGE("[GenerateRSASignature(): no RSA key set]");
return false;
}
if (*signature_length < static_cast<size_t>(RSA_size(rsa_key_))) {
*signature_length = RSA_size(rsa_key_);
return false;
}
if ((padding_scheme & allowed_schemes_) != padding_scheme) {
LOGE("[GenerateRSASignature(): padding_scheme not allowed]");
return false;
}
if (padding_scheme == kSign_RSASSA_PSS) {
// Hash the message using SHA1.
uint8_t hash[SHA_DIGEST_LENGTH];
if (!SHA1(message, message_length, hash)) {
LOGE("[GeneratRSASignature(): error creating signature hash.]");
dump_openssl_error();
return false;
}
// Add PSS padding.
std::vector<uint8_t> padded_digest(*signature_length);
int status = RSA_padding_add_PKCS1_PSS(rsa_key_, &padded_digest[0], hash,
EVP_sha1(), kPssSaltLength);
if (status == -1) {
LOGE("[GeneratRSASignature(): error padding hash.]");
dump_openssl_error();
return false;
}
// Encrypt PSS padded digest.
status = RSA_private_encrypt(*signature_length, &padded_digest[0], signature,
rsa_key_, RSA_NO_PADDING);
if (status == -1) {
LOGE("[GeneratRSASignature(): error in private encrypt.]");
dump_openssl_error();
return false;
}
} else if (padding_scheme == kSign_PKCS1_Block1) {
if (message_length > 83) {
LOGE("[GeneratRSASignature(): RSA digest too large.]");
return false;
}
// Pad the message with PKCS1 padding, and then encrypt.
int status = RSA_private_encrypt(message_length, message, signature,
rsa_key_, RSA_PKCS1_PADDING);
if (status != *signature_length) {
LOGE("[GeneratRSASignature(): error in RSA private encrypt. status=%d]", status);
dump_openssl_error();
return false;
}
} else { // Bad RSA_Padding_Scheme
return false;
}
return true;
}
// Validate message signature
bool SessionContext::ValidateMessage(const uint8_t* given_message,
size_t message_length,
const uint8_t* given_signature,
size_t signature_length) {
if (signature_length != SHA256_DIGEST_LENGTH) {
return false;
}
uint8_t computed_signature[SHA256_DIGEST_LENGTH];
unsigned int md_len = SHA256_DIGEST_LENGTH;
if (!HMAC(EVP_sha256(), &mac_key_server_[0], mac_key_server_.size(),
given_message, message_length, computed_signature, &md_len)) {
LOGE("ValidateMessage: Could not compute signature.");
return false;
}
if (memcmp(given_signature, computed_signature, signature_length)) {
LOGE("Invalid signature given: %s",
wvcdm::HexEncode(given_signature, signature_length).c_str());
LOGE("Invalid signature computed: %s",
wvcdm::HexEncode(computed_signature, signature_length).c_str());
return false;
}
return true;
}
bool SessionContext::CheckNonceOrEntry(const KeyControlBlock& key_control_block,
const std::vector<uint8_t>& pst) {
switch (key_control_block.control_bits() & kControlReplayMask) {
case kControlNonceRequired: // Online license. Nonce always required.
if (!CheckNonce(key_control_block.nonce())) return false;
if (!usage_entry_) {
if (ce_->usage_table()->FindEntry(pst)) {
LOGE("KCB: Cannot create duplicate entries in usage table.");
return false;
}
usage_entry_ = ce_->usage_table()->CreateEntry(pst, this);
}
break; // Offline license. Nonce required on first use.
case kControlNonceOrEntry:
if (!usage_entry_) {
usage_entry_ = ce_->usage_table()->FindEntry(pst);
if (usage_entry_) {
if (usage_entry_->status() == kInactive) return false;
} else {
if (!CheckNonce(key_control_block.nonce())) return false;
usage_entry_ = ce_->usage_table()->CreateEntry(pst, this);
}
} else {
if (usage_entry_->status() == kInactive) return false;
}
break; // Usage table not required. Look at nonce enabled bit.
default:
if ((key_control_block.control_bits() & kControlNonceEnabled) &&
(!CheckNonce(key_control_block.nonce()))) {
LOGE("KCB: BAD Nonce");
return false;
}
}
return true;
}
void SessionContext::StartTimer() {
timer_start_ = time(NULL);
}
uint32_t SessionContext::CurrentTimer() {
time_t now = time(NULL);
return now - timer_start_;
}
OEMCryptoResult SessionContext::LoadKeys(
const uint8_t* message, size_t message_length, const uint8_t* signature,
size_t signature_length, const uint8_t* enc_mac_key_iv,
const uint8_t* enc_mac_keys, size_t num_keys,
const OEMCrypto_KeyObject* key_array, const uint8_t* pst,
size_t pst_length) {
// Validate message signature
if (!ValidateMessage(message, message_length, signature, signature_length)) {
return OEMCrypto_ERROR_SIGNATURE_FAILURE;
}
StartTimer();
// Decrypt and install keys in key object
// Each key will have a key control block. They will all have the same nonce.
bool status = true;
std::vector<uint8_t> key_id;
std::vector<uint8_t> enc_key_data;
std::vector<uint8_t> key_data_iv;
std::vector<uint8_t> key_control;
std::vector<uint8_t> key_control_iv;
std::vector<uint8_t> pstv(pst, pst + pst_length);
for (unsigned int i = 0; i < num_keys; i++) {
key_id.assign(key_array[i].key_id,
key_array[i].key_id + key_array[i].key_id_length);
enc_key_data.assign(key_array[i].key_data,
key_array[i].key_data + key_array[i].key_data_length);
key_data_iv.assign(key_array[i].key_data_iv,
key_array[i].key_data_iv + wvcdm::KEY_IV_SIZE);
if (key_array[i].key_control == NULL) {
status = false;
break;
}
key_control.assign(key_array[i].key_control,
key_array[i].key_control + wvcdm::KEY_CONTROL_SIZE);
key_control_iv.assign(key_array[i].key_control_iv,
key_array[i].key_control_iv + wvcdm::KEY_IV_SIZE);
if (!InstallKey(key_id, enc_key_data, key_data_iv, key_control,
key_control_iv, pstv)) {
status = false;
break;
}
}
FlushNonces();
if (!status) return OEMCrypto_ERROR_UNKNOWN_FAILURE;
// enc_mac_key can be NULL if license renewal is not supported
if (enc_mac_keys != NULL) {
// V2.1 license protocol: update mac keys after processing license response
const std::vector<uint8_t> enc_mac_keys_str = std::vector<uint8_t>(
enc_mac_keys, enc_mac_keys + 2 * wvcdm::MAC_KEY_SIZE);
const std::vector<uint8_t> enc_mac_key_iv_str = std::vector<uint8_t>(
enc_mac_key_iv, enc_mac_key_iv + wvcdm::KEY_IV_SIZE);
if (!UpdateMacKeys(enc_mac_keys_str, enc_mac_key_iv_str)) {
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
}
if (usage_entry_) {
if (!usage_entry_->VerifyOrSetMacKeys(mac_key_server_, mac_key_client_)) {
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
}
return OEMCrypto_SUCCESS;
}
bool SessionContext::InstallKey(const KeyId& key_id,
const std::vector<uint8_t>& key_data,
const std::vector<uint8_t>& key_data_iv,
const std::vector<uint8_t>& key_control,
const std::vector<uint8_t>& key_control_iv,
const std::vector<uint8_t>& pst) {
// Decrypt encrypted key_data using derived encryption key and offered iv
std::vector<uint8_t> content_key;
std::vector<uint8_t> key_control_str;
if (!DecryptMessage(encryption_key_, key_data_iv, key_data, &content_key)) {
LOGE("[Installkey(): Could not decrypt key data]");
return false;
}
#if 0 // Print content key to stdout.
std::cout << " InstallKey: key_id = "
<< wvcdm::b2a_hex(key_id) << std::endl;
std::cout << " InstallKey: content_key = "
<< wvcdm::b2a_hex(content_key) << std::endl;
std::cout << " InstallKey: key_control = "
<< wvcdm::b2a_hex(key_control_str) << std::endl;
#endif
// Key control must be supplied by license server
if (key_control.empty()) {
LOGE("[Installkey(): WARNING: No Key Control]");
return false;
}
if (key_control_iv.empty()) {
LOGE("[Installkey(): ERROR: No Key Control IV]");
return false;
}
if (!DecryptMessage(content_key, key_control_iv, key_control,
&key_control_str)) {
LOGE("[Installkey(): ERROR: Could not decrypt content key]");
return false;
}
KeyControlBlock key_control_block(key_control_str);
if (!key_control_block.valid()) {
LOGE("Error parsing key control.");
return false;
}
if (!CheckNonceOrEntry(key_control_block, pst)) {
LOGE("Failed Nonce/PST check.");
return false;
}
Key key(content_key, key_control_block);
session_keys_.Insert(key_id, key);
return true;
}
bool SessionContext::RefreshKey(const KeyId& key_id,
const std::vector<uint8_t>& key_control,
const std::vector<uint8_t>& key_control_iv) {
if (key_id.empty()) {
// Key control is not encrypted if key id is NULL
KeyControlBlock key_control_block(key_control);
if (!key_control_block.valid()) {
LOGD("Parse key control error.");
return false;
}
if ((key_control_block.control_bits() & kControlNonceEnabled) &&
(!CheckNonce(key_control_block.nonce()))) {
LOGE("KCB: BAD Nonce");
return false;
}
// Apply duration to all keys in this session
session_keys_.UpdateDuration(key_control_block);
return true;
}
Key* content_key = session_keys_.Find(key_id);
if (NULL == content_key) {
LOGD("Error: no matching content key.");
return false;
}
if (key_control.empty()) {
LOGD("Error: no key_control.");
return false;
}
const std::vector<uint8_t> content_key_value = content_key->value();
// Decrypt encrypted key control block
std::vector<uint8_t> control;
if (key_control_iv.empty()) {
LOGD("Key control block is NOT encrypted.");
control = key_control;
} else {
LOGD("Key control block is encrypted.");
if (!DecryptMessage(content_key_value, key_control_iv, key_control,
&control)) {
LOGD("Error decrypting key control block.");
return false;
}
}
KeyControlBlock key_control_block(control);
if (!key_control_block.valid()) {
LOGD("Parse key control error.");
return false;
}
if ((key_control_block.control_bits() & kControlNonceEnabled) &&
(!CheckNonce(key_control_block.nonce()))) {
LOGE("KCB: BAD Nonce");
return false;
}
content_key->UpdateDuration(key_control_block);
return true;
}
bool SessionContext::DecryptRSAKey(const uint8_t* enc_rsa_key,
size_t enc_rsa_key_length,
const uint8_t* enc_rsa_key_iv,
uint8_t* pkcs8_rsa_key) {
// Decrypt rsa key with keybox.
uint8_t iv_buffer[ wvcdm::KEY_IV_SIZE];
memcpy(iv_buffer, enc_rsa_key_iv, wvcdm::KEY_IV_SIZE);
AES_KEY aes_key;
AES_set_decrypt_key(&encryption_key_[0], 128, &aes_key);
AES_cbc_encrypt(enc_rsa_key, pkcs8_rsa_key, enc_rsa_key_length,
&aes_key, iv_buffer, AES_DECRYPT);
return true;
}
bool SessionContext::EncryptRSAKey(const uint8_t* pkcs8_rsa_key,
size_t enc_rsa_key_length,
const uint8_t* enc_rsa_key_iv,
uint8_t* enc_rsa_key) {
// Encrypt rsa key with keybox.
uint8_t iv_buffer[ wvcdm::KEY_IV_SIZE];
memcpy(iv_buffer, enc_rsa_key_iv, wvcdm::KEY_IV_SIZE);
AES_KEY aes_key;
AES_set_encrypt_key(&encryption_key_[0], 128, &aes_key);
AES_cbc_encrypt(pkcs8_rsa_key, enc_rsa_key, enc_rsa_key_length,
&aes_key, iv_buffer, AES_ENCRYPT);
return true;
}
bool SessionContext::LoadRSAKey(uint8_t* pkcs8_rsa_key,
size_t rsa_key_length,
const uint8_t* message,
size_t message_length,
const uint8_t* signature,
size_t signature_length) {
// Validate message signature
if (!ValidateMessage(message, message_length, signature, signature_length)) {
LOGE("[LoadRSAKey(): Could not verify signature]");
return false;
}
if (rsa_key_) {
RSA_free(rsa_key_);
rsa_key_ = NULL;
}
if (rsa_key_length < 8) {
LOGE("[LoadRSAKey(): Very Short Buffer]");
return false;
}
if( (memcmp(pkcs8_rsa_key, "SIGN", 4) == 0) ) {
uint32_t *schemes_n = (uint32_t *)(pkcs8_rsa_key + 4);
allowed_schemes_ = htonl(*schemes_n);
pkcs8_rsa_key += 8;
rsa_key_length -= 8;
}
BIO *bio = BIO_new_mem_buf(pkcs8_rsa_key, rsa_key_length);
if( bio == NULL ) {
LOGE("[LoadRSAKey(): Could not allocate bio buffer]");
return false;
}
bool success = true;
PKCS8_PRIV_KEY_INFO *pkcs8_pki = d2i_PKCS8_PRIV_KEY_INFO_bio(bio, NULL);
if (pkcs8_pki == NULL) {
LOGE("d2i_PKCS8_PRIV_KEY_INFO_bio returned NULL.");
success = false;
}
EVP_PKEY *evp = NULL;
if (success) {
evp = EVP_PKCS82PKEY(pkcs8_pki);
if (evp == NULL) {
LOGE("EVP_PKCS82PKEY returned NULL.");
success = false;
}
}
if (success) {
rsa_key_ = EVP_PKEY_get1_RSA(evp);
if (rsa_key_ == NULL) {
LOGE("PrivateKeyInfo did not contain an RSA key.");
success = false;
}
}
if (evp != NULL) {
EVP_PKEY_free(evp);
}
if (pkcs8_pki != NULL) {
PKCS8_PRIV_KEY_INFO_free(pkcs8_pki);
}
BIO_free(bio);
if (!success) {
return false;
}
switch (RSA_check_key(rsa_key_)) {
case 1: // valid.
return true;
case 0: // not valid.
LOGE("[LoadRSAKey(): rsa key not valid]");
dump_openssl_error();
return false;
default: // -1 == check failed.
LOGE("[LoadRSAKey(): error checking rsa key]");
dump_openssl_error();
return false;
}
}
OEMCryptoResult SessionContext::Generic_Encrypt(const uint8_t* in_buffer,
size_t buffer_length,
const uint8_t* iv,
OEMCrypto_Algorithm algorithm,
uint8_t* out_buffer) {
// Check there is a content key
if (current_content_key() == NULL) {
LOGE("[Generic_Encrypt(): OEMCrypto_ERROR_NO_CONTENT_KEY]");
return OEMCrypto_ERROR_NO_CONTENT_KEY;
}
const std::vector<uint8_t>& key = current_content_key()->value();
const KeyControlBlock& control = current_content_key()->control();
// Set the AES key.
if (static_cast<int>(key.size()) != AES_BLOCK_SIZE) {
LOGE("[Generic_Encrypt(): CONTENT_KEY has wrong size: %d",key.size());
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (!(control.control_bits() & kControlAllowEncrypt)) {
LOGE("[Generic_Encrypt(): control bit says not allowed.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (control.duration() > 0) {
if (control.duration() < CurrentTimer()) {
LOGE("[Generic_Encrypt(): key expired.");
return OEMCrypto_ERROR_KEY_EXPIRED;
}
}
if (control.control_bits() & kControlReplayMask) {
if (!IsUsageEntryValid()) {
LOGE("[Generic_Encrypt(): usage entry not valid]");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
}
if( algorithm != OEMCrypto_AES_CBC_128_NO_PADDING ) {
LOGE("[Generic_Encrypt(): algorithm bad.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if( buffer_length % AES_BLOCK_SIZE != 0 ) {
LOGE("[Generic_Encrypt(): buffers size bad.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
const uint8_t* key_u8 = &key[0];
AES_KEY aes_key;
if (AES_set_encrypt_key(key_u8, AES_BLOCK_SIZE * 8, &aes_key) != 0) {
LOGE("[Generic_Encrypt(): FAILURE]");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
uint8_t iv_buffer[ wvcdm::KEY_IV_SIZE];
memcpy(iv_buffer, iv, wvcdm::KEY_IV_SIZE);
AES_cbc_encrypt(in_buffer, out_buffer, buffer_length,
&aes_key, iv_buffer, AES_ENCRYPT);
return OEMCrypto_SUCCESS;
}
OEMCryptoResult SessionContext::Generic_Decrypt(const uint8_t* in_buffer,
size_t buffer_length,
const uint8_t* iv,
OEMCrypto_Algorithm algorithm,
uint8_t* out_buffer) {
// Check there is a content key
if (current_content_key() == NULL) {
LOGE("[Generic_Decrypt(): OEMCrypto_ERROR_NO_CONTENT_KEY]");
return OEMCrypto_ERROR_NO_CONTENT_KEY;
}
const std::vector<uint8_t>& key = current_content_key()->value();
const KeyControlBlock& control = current_content_key()->control();
// Set the AES key.
if (static_cast<int>(key.size()) != AES_BLOCK_SIZE) {
LOGE("[Generic_Decrypt(): CONTENT_KEY has wrong size.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (!(control.control_bits() & kControlAllowDecrypt)) {
LOGE("[Generic_Decrypt(): control bit says not allowed.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (control.control_bits() & kControlDataPathSecure) {
LOGE("[Generic_Decrypt(): control bit says secure path only.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (control.duration() > 0) {
if (control.duration() < CurrentTimer()) {
LOGE("[Generic_Decrypt(): key expired.");
return OEMCrypto_ERROR_KEY_EXPIRED;
}
}
if (control.control_bits() & kControlReplayMask) {
if (!IsUsageEntryValid()) {
LOGE("[Generic_Decrypt(): usage entry not valid]");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
}
if( algorithm != OEMCrypto_AES_CBC_128_NO_PADDING ) {
LOGE("[Generic_Decrypt(): bad algorithm.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if( buffer_length % AES_BLOCK_SIZE != 0 ) {
LOGE("[Generic_Decrypt(): bad buffer size.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
const uint8_t* key_u8 = &key[0];
AES_KEY aes_key;
if (AES_set_decrypt_key(key_u8, AES_BLOCK_SIZE * 8, &aes_key) != 0) {
LOGE("[Generic_Decrypt(): FAILURE]");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
uint8_t iv_buffer[ wvcdm::KEY_IV_SIZE];
memcpy(iv_buffer, iv, wvcdm::KEY_IV_SIZE);
AES_cbc_encrypt(in_buffer, out_buffer, buffer_length,
&aes_key, iv_buffer, AES_DECRYPT);
return OEMCrypto_SUCCESS;
}
OEMCryptoResult SessionContext::Generic_Sign(const uint8_t* in_buffer,
size_t buffer_length,
OEMCrypto_Algorithm algorithm,
uint8_t* signature,
size_t* signature_length) {
// Check there is a content key
if (current_content_key() == NULL) {
LOGE("[Generic_Sign(): OEMCrypto_ERROR_NO_CONTENT_KEY]");
return OEMCrypto_ERROR_NO_CONTENT_KEY;
}
if (*signature_length < SHA256_DIGEST_LENGTH) {
*signature_length = SHA256_DIGEST_LENGTH;
LOGE("[Generic_Sign(): bad signature length.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
const std::vector<uint8_t>& key = current_content_key()->value();
const KeyControlBlock& control = current_content_key()->control();
if (static_cast<int>(key.size()) != SHA256_DIGEST_LENGTH) {
LOGE("[Generic_Sign(): CONTENT_KEY has wrong size; %d", key.size());
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (!(control.control_bits() & kControlAllowSign)) {
LOGE("[Generic_Sign(): control bit says not allowed.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (control.duration() > 0) {
if (control.duration() < CurrentTimer()) {
LOGE("[Generic_Sign(): key expired.");
return OEMCrypto_ERROR_KEY_EXPIRED;
}
}
if (control.control_bits() & kControlReplayMask) {
if (!IsUsageEntryValid()) {
LOGE("[Generic_Sign(): usage entry not valid]");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
}
if( algorithm != OEMCrypto_HMAC_SHA256 ) {
LOGE("[Generic_Sign(): bad algorithm.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
unsigned int md_len = *signature_length;
if (HMAC(EVP_sha256(), &key[0], key.size(),
in_buffer, buffer_length, signature, &md_len)) {
*signature_length = md_len;
return OEMCrypto_SUCCESS;
}
LOGE("[Generic_Sign(): hmac failed.");
dump_openssl_error();
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
OEMCryptoResult SessionContext::Generic_Verify(const uint8_t* in_buffer,
size_t buffer_length,
OEMCrypto_Algorithm algorithm,
const uint8_t* signature,
size_t signature_length) {
// Check there is a content key
if (current_content_key() == NULL) {
LOGE("[Decrypt_Verify(): OEMCrypto_ERROR_NO_CONTENT_KEY]");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (signature_length < SHA256_DIGEST_LENGTH) {
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
const std::vector<uint8_t>& key = current_content_key()->value();
const KeyControlBlock& control = current_content_key()->control();
if (static_cast<int>(key.size()) != SHA256_DIGEST_LENGTH) {
LOGE("[Generic_Verify(): CONTENT_KEY has wrong size: %d", key.size());
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (!(control.control_bits() & kControlAllowVerify)) {
LOGE("[Generic_Verify(): control bit says not allowed.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
if (control.duration() > 0) {
if (control.duration() < CurrentTimer()) {
LOGE("[Generic_Verify(): key expired.");
return OEMCrypto_ERROR_KEY_EXPIRED;
}
}
if (control.control_bits() & kControlReplayMask) {
if (!IsUsageEntryValid()) {
LOGE("[Generic_Verify(): usage entry not valid]");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
}
if( algorithm != OEMCrypto_HMAC_SHA256 ) {
LOGE("[Generic_Verify(): bad algorithm.");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
unsigned int md_len = signature_length;
uint8_t computed_signature[SHA256_DIGEST_LENGTH];
if (HMAC(EVP_sha256(), &key[0], key.size(),
in_buffer, buffer_length, computed_signature, &md_len)) {
if (0 == memcmp(signature, computed_signature, SHA256_DIGEST_LENGTH)) {
return OEMCrypto_SUCCESS;
} else {
return OEMCrypto_ERROR_SIGNATURE_FAILURE;
}
}
LOGE("[Generic_Verify(): HMAC failed.");
dump_openssl_error();
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
bool SessionContext::UpdateMacKeys(const std::vector<uint8_t>& enc_mac_keys,
const std::vector<uint8_t>& iv) {
// Decrypt mac key from enc_mac_key using device_keya
std::vector<uint8_t> mac_keys;
if (!DecryptMessage(encryption_key_, iv, enc_mac_keys, &mac_keys)) {
return false;
}
mac_key_server_ = std::vector<uint8_t>(mac_keys.begin(),
mac_keys.begin()+wvcdm::MAC_KEY_SIZE);
mac_key_client_ = std::vector<uint8_t>(mac_keys.begin()+wvcdm::MAC_KEY_SIZE,
mac_keys.end());
return true;
}
bool SessionContext::SelectContentKey(const KeyId& key_id) {
const Key* content_key = session_keys_.Find(key_id);
#if 0
std::cout << " Select Key: key_id = "
<< wvcdm::b2a_hex(key_id) << std::endl;
std::cout << " Select Key: key = "
<< wvcdm::b2a_hex(content_key->value()) << std::endl;
#endif
if (NULL == content_key) {
LOGE("[SelectContentKey(): No key matches key id]");
return false;
}
current_content_key_ = content_key;
return true;
}
void SessionContext::AddNonce(uint32_t nonce) {
nonce_table_.AddNonce(nonce);
}
bool SessionContext::CheckNonce(uint32_t nonce) {
return nonce_table_.CheckNonce(nonce);
}
void SessionContext::FlushNonces() {
nonce_table_.Flush();
}
bool SessionContext::IsUsageEntryValid() {
if (!usage_entry_) return false;
return usage_entry_->UpdateTime();
}
void SessionContext::ReleaseUsageEntry() { usage_entry_ = NULL; }
CryptoEngine::CryptoEngine() :
ce_state_(CE_INITIALIZED), current_session_(NULL) {
valid_ = true;
ERR_load_crypto_strings();
// These are made up numbers, just for illustration.
current_hdcp_capability_ = 0x1;
maximum_hdcp_capability_ = 0x2;
// If local_display_ is true, we pretend we are using a built-in display,
// instead of HDMI or WiFi output.
local_display_ = false;
usage_table_ = new UsageTable(this);
}
CryptoEngine::~CryptoEngine() {
current_session_ = NULL;
sessions_.clear();
if (usage_table_) delete usage_table_;
}
void CryptoEngine::Terminate() {
}
KeyboxError CryptoEngine::ValidateKeybox() { return keybox_.Validate(); }
SessionId CryptoEngine::CreateSession() {
wvcdm::AutoLock lock(session_table_lock_);
static int unique_id = 1;
SessionId sid = (SessionId)++unique_id;
SessionContext* sctx = new SessionContext(this, sid);
sessions_[sid] = sctx;
return sid;
}
bool CryptoEngine::DestroySession(SessionId sid) {
SessionContext* sctx = FindSession(sid);
wvcdm::AutoLock lock(session_table_lock_);
if (sctx) {
sessions_.erase(sid);
delete sctx;
return true;
} else {
return false;
}
}
SessionContext* CryptoEngine::FindSession(SessionId sid) {
wvcdm::AutoLock lock(session_table_lock_);
ActiveSessions::iterator it = sessions_.find(sid);
if (it != sessions_.end()) {
return it->second;
}
return NULL;
}
// Internal utility function to decrypt the message
bool SessionContext::DecryptMessage(const std::vector<uint8_t>& key,
const std::vector<uint8_t>& iv,
const std::vector<uint8_t>& message,
std::vector<uint8_t>* decrypted) {
if (key.empty() || iv.empty() || message.empty() || !decrypted) {
LOGE("[DecryptMessage(): OEMCrypto_ERROR_INVALID_CONTEXT]");
return false;
}
decrypted->resize(message.size());
uint8_t iv_buffer[16];
memcpy(iv_buffer, &iv[0], 16);
AES_KEY aes_key;
AES_set_decrypt_key(&key[0], 128, &aes_key);
AES_cbc_encrypt(&message[0], &(decrypted->front()), message.size(),
&aes_key, iv_buffer, AES_DECRYPT);
return true;
}
OEMCryptoResult SessionContext::DecryptCTR(
const uint8_t* iv, size_t block_offset, const uint8_t* cipher_data,
size_t cipher_data_length, bool is_encrypted, uint8_t* clear_data,
BufferType buffer_type) {
// If the data is clear, we do not need a current key selected.
if (!is_encrypted) {
if (buffer_type != kBufferTypeDirect) {
memcpy(reinterpret_cast<uint8_t*>(clear_data), cipher_data,
cipher_data_length);
return OEMCrypto_SUCCESS;
}
// For reference implementation, we quietly drop the clear direct video.
return OEMCrypto_SUCCESS;
}
// Check there is a content key
if (current_content_key() == NULL) {
LOGE("[DecryptCTR(): OEMCrypto_ERROR_NO_CONTENT_KEY]");
return OEMCrypto_ERROR_DECRYPT_FAILED;
}
const KeyControlBlock& control = current_content_key()->control();
if (control.control_bits() & kControlDataPathSecure) {
if (buffer_type == kBufferTypeClear) {
LOGE("[DecryptCTR(): Secure key with insecure buffer]");
return OEMCrypto_ERROR_DECRYPT_FAILED;
}
}
if (control.duration() > 0) {
if (control.duration() < CurrentTimer()) {
LOGE("[DecryptCTR(): KEY_EXPIRED]");
return OEMCrypto_ERROR_KEY_EXPIRED;
}
}
if (control.control_bits() & kControlReplayMask) {
if (!IsUsageEntryValid()) {
LOGE("[DecryptCTR(): usage entry not valid]");
return OEMCrypto_ERROR_UNKNOWN_FAILURE;
}
}
if (!ce_->local_display()) { // Only look at HDCP if the display is not
// local.
if (control.control_bits() & kControlHDCPRequired) {
uint8_t required_hdcp =
(control.control_bits() & kControlHDCPVersionMask) >>
kControlHDCPVersionShift;
// For reference implementation, we pretend we can handle the current
// HDCP version.
if (required_hdcp > ce_->current_hdcp_capability() ||
ce_->current_hdcp_capability() == 0) {
return OEMCrypto_ERROR_INSUFFICIENT_HDCP;
}
}
}
const std::vector<uint8_t>& content_key = current_content_key()->value();
// Set the AES key.
if (static_cast<int>(content_key.size()) != AES_BLOCK_SIZE) {
LOGE("[DecryptCTR(): CONTENT_KEY has wrong size: %d", content_key.size());
return OEMCrypto_ERROR_DECRYPT_FAILED;
}
const uint8_t* key_u8 = &content_key[0];
AES_KEY aes_key;
if (AES_set_encrypt_key(key_u8, AES_BLOCK_SIZE * 8, &aes_key) != 0) {
LOGE("[DecryptCTR(): FAILURE]");
return OEMCrypto_ERROR_DECRYPT_FAILED;
}
if (buffer_type == kBufferTypeDirect) {
// For reference implementation, we quietly drop the decrypted direct video.
return OEMCrypto_SUCCESS;
}
if (buffer_type == kBufferTypeSecure) {
// For reference implementation, we also quietly drop secure data.
return OEMCrypto_SUCCESS;
}
// Local copy (will be modified).
uint8_t aes_iv[AES_BLOCK_SIZE];
memcpy(aes_iv, &iv[0], AES_BLOCK_SIZE);
// Encrypt the IV.
uint8_t ecount_buf[AES_BLOCK_SIZE];
// The CENC spec specifies we increment only the low 64 bits of the IV
// counter, and leave the high 64 bits alone. This is different from the
// OpenSSL implementation, which increments the entire 128 bit iv. That is
// why we implement the CTR loop ourselves.
size_t l = 0;
while (l < cipher_data_length) {
AES_encrypt(aes_iv, ecount_buf, &aes_key);
for (int n = block_offset; n < AES_BLOCK_SIZE && l < cipher_data_length;
++n, ++l) {
clear_data[l] = cipher_data[l] ^ ecount_buf[n];
}
ctr128_inc64(aes_iv);
block_offset = 0;
}
return OEMCrypto_SUCCESS;
}
void NonceTable::AddNonce(uint32_t nonce) {
int new_slot = -1;
int oldest_slot = -1;
// Flush any nonces that have been checked but not flushed.
// After flush, nonces will be either valid or invalid.
Flush();
for (int i = 0; i < kTableSize; ++i) {
// Increase age of all valid nonces.
if (kNTStateValid == state_[i]) {
++age_[i];
if (-1 == oldest_slot) {
oldest_slot = i;
} else {
if (age_[i] > age_[oldest_slot]) {
oldest_slot = i;
}
}
} else {
if (-1 == new_slot) {
age_[i] = 0;
nonces_[i] = nonce;
state_[i] = kNTStateValid;
new_slot = i;
}
}
}
if (-1 == new_slot) {
// reuse oldest
// assert (oldest_slot != -1)
int i = oldest_slot;
age_[i] = 0;
nonces_[i] = nonce;
state_[i] = kNTStateValid;
}
}
bool NonceTable::CheckNonce(uint32_t nonce) {
for (int i = 0; i < kTableSize; ++i) {
if (kNTStateInvalid != state_[i]) {
if (nonce == nonces_[i]) {
state_[i] = kNTStateFlushPending;
return true;
}
}
}
return false;
}
void NonceTable::Flush() {
for (int i = 0; i < kTableSize; ++i) {
if (kNTStateFlushPending == state_[i]) {
state_[i] = kNTStateInvalid;
}
}
}
}; // namespace wvoec_mock
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