/*
* Copyright 2012 The Android Open Source Project
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <utils/UniquePtr.h>
#include <sys/socket.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <openssl/dsa.h>
#include <openssl/engine.h>
#include <openssl/ec.h>
#include <openssl/evp.h>
#include <openssl/objects.h>
#include <openssl/rsa.h>
//#define LOG_NDEBUG 0
#define LOG_TAG "OpenSSL-keystore"
#include <cutils/log.h>
#include <binder/IServiceManager.h>
#include <keystore/keystore.h>
#include <keystore/IKeystoreService.h>
#include "methods.h"
using namespace android;
#define DYNAMIC_ENGINE
const char* kKeystoreEngineId = "keystore";
static const char* kKeystoreEngineDesc = "Android keystore engine";
/*
* ex_data index for keystore's key alias.
*/
int rsa_key_handle;
int dsa_key_handle;
/*
* Only initialize the *_key_handle once.
*/
static pthread_once_t key_handle_control = PTHREAD_ONCE_INIT;
/**
* Many OpenSSL APIs take ownership of an argument on success but don't free the argument
* on failure. This means we need to tell our scoped pointers when we've transferred ownership,
* without triggering a warning by not using the result of release().
*/
#define OWNERSHIP_TRANSFERRED(obj) \
typeof (obj.release()) _dummy __attribute__((unused)) = obj.release()
struct ENGINE_Delete {
void operator()(ENGINE* p) const {
ENGINE_free(p);
}
};
typedef UniquePtr<ENGINE, ENGINE_Delete> Unique_ENGINE;
struct EVP_PKEY_Delete {
void operator()(EVP_PKEY* p) const {
EVP_PKEY_free(p);
}
};
typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY;
/**
* Called to initialize RSA's ex_data for the key_id handle. This should
* only be called when protected by a lock.
*/
static void init_key_handle() {
rsa_key_handle = RSA_get_ex_new_index(0, NULL, keyhandle_new, keyhandle_dup, keyhandle_free);
dsa_key_handle = DSA_get_ex_new_index(0, NULL, keyhandle_new, keyhandle_dup, keyhandle_free);
}
static EVP_PKEY* keystore_loadkey(ENGINE* e, const char* key_id, UI_METHOD* ui_method,
void* callback_data) {
#if LOG_NDEBUG
(void)ui_method;
(void)callback_data;
#else
ALOGV("keystore_loadkey(%p, \"%s\", %p, %p)", e, key_id, ui_method, callback_data);
#endif
sp<IServiceManager> sm = defaultServiceManager();
sp<IBinder> binder = sm->getService(String16("android.security.keystore"));
sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);
if (service == NULL) {
ALOGE("could not contact keystore");
return 0;
}
uint8_t *pubkey = NULL;
size_t pubkeyLen;
int32_t ret = service->get_pubkey(String16(key_id), &pubkey, &pubkeyLen);
if (ret < 0) {
ALOGW("could not contact keystore");
free(pubkey);
return NULL;
} else if (ret != 0) {
ALOGW("keystore reports error: %d", ret);
free(pubkey);
return NULL;
}
const unsigned char* tmp = reinterpret_cast<const unsigned char*>(pubkey);
Unique_EVP_PKEY pkey(d2i_PUBKEY(NULL, &tmp, pubkeyLen));
free(pubkey);
if (pkey.get() == NULL) {
ALOGW("Cannot convert pubkey");
return NULL;
}
switch (EVP_PKEY_type(pkey->type)) {
case EVP_PKEY_DSA: {
dsa_pkey_setup(e, pkey.get(), key_id);
break;
}
case EVP_PKEY_RSA: {
rsa_pkey_setup(e, pkey.get(), key_id);
break;
}
case EVP_PKEY_EC: {
ecdsa_pkey_setup(e, pkey.get(), key_id);
break;
}
default:
ALOGE("Unsupported key type %d", EVP_PKEY_type(pkey->type));
return NULL;
}
return pkey.release();
}
static const ENGINE_CMD_DEFN keystore_cmd_defns[] = {
{0, NULL, NULL, 0}
};
static int keystore_engine_setup(ENGINE* e) {
ALOGV("keystore_engine_setup");
if (!ENGINE_set_id(e, kKeystoreEngineId)
|| !ENGINE_set_name(e, kKeystoreEngineDesc)
|| !ENGINE_set_load_privkey_function(e, keystore_loadkey)
|| !ENGINE_set_load_pubkey_function(e, keystore_loadkey)
|| !ENGINE_set_flags(e, 0)
|| !ENGINE_set_cmd_defns(e, keystore_cmd_defns)) {
ALOGE("Could not set up keystore engine");
return 0;
}
/* We need a handle in the keys types as well for keygen if it's not already initialized. */
pthread_once(&key_handle_control, init_key_handle);
if ((rsa_key_handle < 0) || (dsa_key_handle < 0)) {
ALOGE("Could not set up ex_data index");
return 0;
}
if (!dsa_register(e)) {
ALOGE("DSA registration failed");
return 0;
} else if (!ecdsa_register(e)) {
ALOGE("ECDSA registration failed");
return 0;
} else if (!rsa_register(e)) {
ALOGE("RSA registration failed");
return 0;
}
return 1;
}
ENGINE* ENGINE_keystore() {
ALOGV("ENGINE_keystore");
Unique_ENGINE engine(ENGINE_new());
if (engine.get() == NULL) {
return NULL;
}
if (!keystore_engine_setup(engine.get())) {
return NULL;
}
return engine.release();
}
static int keystore_bind_fn(ENGINE *e, const char *id) {
ALOGV("keystore_bind_fn");
if (!id) {
return 0;
}
if (strcmp(id, kKeystoreEngineId)) {
return 0;
}
if (!keystore_engine_setup(e)) {
return 0;
}
return 1;
}
extern "C" {
#undef OPENSSL_EXPORT
#define OPENSSL_EXPORT extern __attribute__ ((visibility ("default")))
IMPLEMENT_DYNAMIC_CHECK_FN()
IMPLEMENT_DYNAMIC_BIND_FN(keystore_bind_fn)
};