softkeymaster/keymaster_openssl.cpp - platform/system/security - Git at Google

 /*
  * Copyright (C) 2012 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 #include <errno.h>
 #include <string.h>
 #include <stdint.h>

 #include <keystore/keystore.h>

 #include <hardware/hardware.h>
 #include <hardware/keymaster.h>

 #include <openssl/evp.h>
 #include <openssl/bio.h>
 #include <openssl/rsa.h>
 #include <openssl/err.h>
 #include <openssl/x509.h>

 #include <utils/UniquePtr.h>

 // For debugging
 //#define LOG_NDEBUG 0

 #define LOG_TAG "OpenSSLKeyMaster"
 #include <cutils/log.h>

 struct BIGNUM_Delete {
     void operator()(BIGNUM* p) const {
         BN_free(p);
     }
 };
 typedef UniquePtr<BIGNUM, BIGNUM_Delete> Unique_BIGNUM;

 struct EVP_PKEY_Delete {
     void operator()(EVP_PKEY* p) const {
         EVP_PKEY_free(p);
     }
 };
 typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY;

 struct PKCS8_PRIV_KEY_INFO_Delete {
     void operator()(PKCS8_PRIV_KEY_INFO* p) const {
         PKCS8_PRIV_KEY_INFO_free(p);
     }
 };
 typedef UniquePtr<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_Delete> Unique_PKCS8_PRIV_KEY_INFO;

 struct RSA_Delete {
     void operator()(RSA* p) const {
         RSA_free(p);
     }
 };
 typedef UniquePtr<RSA, RSA_Delete> Unique_RSA;

 typedef UniquePtr<keymaster_device_t> Unique_keymaster_device_t;

 /**
  * 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()


 /*
  * Checks this thread's OpenSSL error queue and logs if
  * necessary.
  */
 static void logOpenSSLError(const char* location) {
     int error = ERR_get_error();

     if (error != 0) {
         char message[256];
         ERR_error_string_n(error, message, sizeof(message));
         ALOGE("OpenSSL error in %s %d: %s", location, error, message);
     }

     ERR_clear_error();
     ERR_remove_state(0);
 }

 static int wrap_key(EVP_PKEY* pkey, int type, uint8_t** keyBlob, size_t* keyBlobLength) {
     /* Find the length of each size */
     int publicLen = i2d_PublicKey(pkey, NULL);
     int privateLen = i2d_PrivateKey(pkey, NULL);

     if (privateLen <= 0 || publicLen <= 0) {
         ALOGE("private or public key size was too big");
         return -1;
     }

     /* int type + int size + private key data + int size + public key data */
     *keyBlobLength = get_softkey_header_size() + sizeof(int) + sizeof(int) + privateLen
             + sizeof(int) + publicLen;

     UniquePtr<unsigned char[]> derData(new unsigned char[*keyBlobLength]);
     if (derData.get() == NULL) {
         ALOGE("could not allocate memory for key blob");
         return -1;
     }
     unsigned char* p = derData.get();

     /* Write the magic value for software keys. */
     p = add_softkey_header(p, *keyBlobLength);

     /* Write key type to allocated buffer */
     for (int i = sizeof(int) - 1; i >= 0; i--) {
         *p++ = (type >> (8*i)) & 0xFF;
     }

     /* Write public key to allocated buffer */
     for (int i = sizeof(int) - 1; i >= 0; i--) {
         *p++ = (publicLen >> (8*i)) & 0xFF;
     }
     if (i2d_PublicKey(pkey, &p) != publicLen) {
         logOpenSSLError("wrap_key");
         return -1;
     }

     /* Write private key to allocated buffer */
     for (int i = sizeof(int) - 1; i >= 0; i--) {
         *p++ = (privateLen >> (8*i)) & 0xFF;
     }
     if (i2d_PrivateKey(pkey, &p) != privateLen) {
         logOpenSSLError("wrap_key");
         return -1;
     }

     *keyBlob = derData.release();

     return 0;
 }

 static EVP_PKEY* unwrap_key(const uint8_t* keyBlob, const size_t keyBlobLength) {
     long publicLen = 0;
     long privateLen = 0;
     const uint8_t* p = keyBlob;
     const uint8_t *const end = keyBlob + keyBlobLength;

     if (keyBlob == NULL) {
         ALOGE("supplied key blob was NULL");
         return NULL;
     }

     // Should be large enough for:
     // int32 magic, int32 type, int32 pubLen, char* pub, int32 privLen, char* priv
     if (keyBlobLength < (get_softkey_header_size() + sizeof(int) + sizeof(int) + 1
             + sizeof(int) + 1)) {
         ALOGE("key blob appears to be truncated");
         return NULL;
     }

     if (!is_softkey(p, keyBlobLength)) {
         ALOGE("cannot read key; it was not made by this keymaster");
         return NULL;
     }
     p += get_softkey_header_size();

     int type = 0;
     for (size_t i = 0; i < sizeof(int); i++) {
         type = (type << 8) | *p++;
     }

     Unique_EVP_PKEY pkey(EVP_PKEY_new());
     if (pkey.get() == NULL) {
         logOpenSSLError("unwrap_key");
         return NULL;
     }

     for (size_t i = 0; i < sizeof(int); i++) {
         publicLen = (publicLen << 8) | *p++;
     }
     if (p + publicLen > end) {
         ALOGE("public key length encoding error: size=%ld, end=%d", publicLen, end - p);
         return NULL;
     }
     EVP_PKEY* tmp = pkey.get();
     d2i_PublicKey(type, &tmp, &p, publicLen);

     if (end - p < 2) {
         ALOGE("private key truncated");
         return NULL;
     }
     for (size_t i = 0; i < sizeof(int); i++) {
         privateLen = (privateLen << 8) | *p++;
     }
     if (p + privateLen > end) {
         ALOGE("private key length encoding error: size=%ld, end=%d", privateLen, end - p);
         return NULL;
     }
     d2i_PrivateKey(type, &tmp, &p, privateLen);

     return pkey.release();
 }

 static int openssl_generate_keypair(const keymaster_device_t* dev,
         const keymaster_keypair_t key_type, const void* key_params,
         uint8_t** keyBlob, size_t* keyBlobLength) {
     ssize_t privateLen, publicLen;

     if (key_type != TYPE_RSA) {
         ALOGW("Unsupported key type %d", key_type);
         return -1;
     } else if (key_params == NULL) {
         ALOGW("key_params == null");
         return -1;
     }

     keymaster_rsa_keygen_params_t* rsa_params = (keymaster_rsa_keygen_params_t*) key_params;

     Unique_BIGNUM bn(BN_new());
     if (bn.get() == NULL) {
         logOpenSSLError("openssl_generate_keypair");
         return -1;
     }

     if (BN_set_word(bn.get(), rsa_params->public_exponent) == 0) {
         logOpenSSLError("openssl_generate_keypair");
         return -1;
     }

     /* initialize RSA */
     Unique_RSA rsa(RSA_new());
     if (rsa.get() == NULL) {
         logOpenSSLError("openssl_generate_keypair");
         return -1;
     }

     if (!RSA_generate_key_ex(rsa.get(), rsa_params->modulus_size, bn.get(), NULL)
             || RSA_check_key(rsa.get()) < 0) {
         logOpenSSLError("openssl_generate_keypair");
         return -1;
     }

     /* assign to EVP */
     Unique_EVP_PKEY pkey(EVP_PKEY_new());
     if (pkey.get() == NULL) {
         logOpenSSLError("openssl_generate_keypair");
         return -1;
     }

     if (EVP_PKEY_assign_RSA(pkey.get(), rsa.get()) == 0) {
         logOpenSSLError("openssl_generate_keypair");
         return -1;
     }
     OWNERSHIP_TRANSFERRED(rsa);

     if (wrap_key(pkey.get(), EVP_PKEY_RSA, keyBlob, keyBlobLength)) {
         return -1;
     }

     return 0;
 }

 static int openssl_import_keypair(const keymaster_device_t* dev,
         const uint8_t* key, const size_t key_length,
         uint8_t** key_blob, size_t* key_blob_length) {
     int response = -1;

     if (key == NULL) {
         ALOGW("input key == NULL");
         return -1;
     } else if (key_blob == NULL || key_blob_length == NULL) {
         ALOGW("output key blob or length == NULL");
         return -1;
     }

     Unique_PKCS8_PRIV_KEY_INFO pkcs8(d2i_PKCS8_PRIV_KEY_INFO(NULL, &key, key_length));
     if (pkcs8.get() == NULL) {
         logOpenSSLError("openssl_import_keypair");
         return -1;
     }

     /* assign to EVP */
     Unique_EVP_PKEY pkey(EVP_PKCS82PKEY(pkcs8.get()));
     if (pkey.get() == NULL) {
         logOpenSSLError("openssl_import_keypair");
         return -1;
     }
     OWNERSHIP_TRANSFERRED(pkcs8);

     if (wrap_key(pkey.get(), EVP_PKEY_type(pkey->type), key_blob, key_blob_length)) {
         return -1;
     }

     return 0;
 }

 static int openssl_get_keypair_public(const struct keymaster_device* dev,
         const uint8_t* key_blob, const size_t key_blob_length,
         uint8_t** x509_data, size_t* x509_data_length) {

     if (x509_data == NULL || x509_data_length == NULL) {
         ALOGW("output public key buffer == NULL");
         return -1;
     }

     Unique_EVP_PKEY pkey(unwrap_key(key_blob, key_blob_length));
     if (pkey.get() == NULL) {
         return -1;
     }

     int len = i2d_PUBKEY(pkey.get(), NULL);
     if (len <= 0) {
         logOpenSSLError("openssl_get_keypair_public");
         return -1;
     }

     UniquePtr<uint8_t> key(static_cast<uint8_t*>(malloc(len)));
     if (key.get() == NULL) {
         ALOGE("Could not allocate memory for public key data");
         return -1;
     }

     unsigned char* tmp = reinterpret_cast<unsigned char*>(key.get());
     if (i2d_PUBKEY(pkey.get(), &tmp) != len) {
         logOpenSSLError("openssl_get_keypair_public");
         return -1;
     }

     ALOGV("Length of x509 data is %d", len);
     *x509_data_length = len;
     *x509_data = key.release();

     return 0;
 }

 static int openssl_sign_data(const keymaster_device_t* dev,
         const void* params,
         const uint8_t* keyBlob, const size_t keyBlobLength,
         const uint8_t* data, const size_t dataLength,
         uint8_t** signedData, size_t* signedDataLength) {

     int result = -1;
     EVP_MD_CTX ctx;
     size_t maxSize;

     if (data == NULL) {
         ALOGW("input data to sign == NULL");
         return -1;
     } else if (signedData == NULL || signedDataLength == NULL) {
         ALOGW("output signature buffer == NULL");
         return -1;
     }

     Unique_EVP_PKEY pkey(unwrap_key(keyBlob, keyBlobLength));
     if (pkey.get() == NULL) {
         return -1;
     }

     if (EVP_PKEY_type(pkey->type) != EVP_PKEY_RSA) {
         ALOGW("Cannot handle non-RSA keys yet");
         return -1;
     }

     keymaster_rsa_sign_params_t* sign_params = (keymaster_rsa_sign_params_t*) params;
     if (sign_params->digest_type != DIGEST_NONE) {
         ALOGW("Cannot handle digest type %d", sign_params->digest_type);
         return -1;
     } else if (sign_params->padding_type != PADDING_NONE) {
         ALOGW("Cannot handle padding type %d", sign_params->padding_type);
         return -1;
     }

     Unique_RSA rsa(EVP_PKEY_get1_RSA(pkey.get()));
     if (rsa.get() == NULL) {
         logOpenSSLError("openssl_sign_data");
         return -1;
     }

     UniquePtr<uint8_t> signedDataPtr(reinterpret_cast<uint8_t*>(malloc(dataLength)));
     if (signedDataPtr.get() == NULL) {
         logOpenSSLError("openssl_sign_data");
         return -1;
     }

     unsigned char* tmp = reinterpret_cast<unsigned char*>(signedDataPtr.get());
     if (RSA_private_encrypt(dataLength, data, tmp, rsa.get(), RSA_NO_PADDING) <= 0) {
         logOpenSSLError("openssl_sign_data");
         return -1;
     }

     *signedDataLength = dataLength;
     *signedData = signedDataPtr.release();
     return 0;
 }

 static int openssl_verify_data(const keymaster_device_t* dev,
         const void* params,
         const uint8_t* keyBlob, const size_t keyBlobLength,
         const uint8_t* signedData, const size_t signedDataLength,
         const uint8_t* signature, const size_t signatureLength) {

     if (signedData == NULL || signature == NULL) {
         ALOGW("data or signature buffers == NULL");
         return -1;
     }

     Unique_EVP_PKEY pkey(unwrap_key(keyBlob, keyBlobLength));
     if (pkey.get() == NULL) {
         return -1;
     }

     if (EVP_PKEY_type(pkey->type) != EVP_PKEY_RSA) {
         ALOGW("Cannot handle non-RSA keys yet");
         return -1;
     }

     keymaster_rsa_sign_params_t* sign_params = (keymaster_rsa_sign_params_t*) params;
     if (sign_params->digest_type != DIGEST_NONE) {
         ALOGW("Cannot handle digest type %d", sign_params->digest_type);
         return -1;
     } else if (sign_params->padding_type != PADDING_NONE) {
         ALOGW("Cannot handle padding type %d", sign_params->padding_type);
         return -1;
     } else if (signatureLength != signedDataLength) {
         ALOGW("signed data length must be signature length");
         return -1;
     }

     Unique_RSA rsa(EVP_PKEY_get1_RSA(pkey.get()));
     if (rsa.get() == NULL) {
         logOpenSSLError("openssl_verify_data");
         return -1;
     }

     UniquePtr<uint8_t> dataPtr(reinterpret_cast<uint8_t*>(malloc(signedDataLength)));
     if (dataPtr.get() == NULL) {
         logOpenSSLError("openssl_verify_data");
         return -1;
     }

     unsigned char* tmp = reinterpret_cast<unsigned char*>(dataPtr.get());
     if (!RSA_public_decrypt(signatureLength, signature, tmp, rsa.get(), RSA_NO_PADDING)) {
         logOpenSSLError("openssl_verify_data");
         return -1;
     }

     int result = 0;
     for (size_t i = 0; i < signedDataLength; i++) {
         result |= tmp[i] ^ signedData[i];
     }

     return result == 0 ? 0 : -1;
 }

 /* Close an opened OpenSSL instance */
 static int openssl_close(hw_device_t *dev) {
     free(dev);
     return 0;
 }

 /*
  * Generic device handling
  */
 static int openssl_open(const hw_module_t* module, const char* name,
         hw_device_t** device) {
     if (strcmp(name, KEYSTORE_KEYMASTER) != 0)
         return -EINVAL;

     Unique_keymaster_device_t dev(new keymaster_device_t);
     if (dev.get() == NULL)
         return -ENOMEM;

     dev->common.tag = HARDWARE_DEVICE_TAG;
     dev->common.version = 1;
     dev->common.module = (struct hw_module_t*) module;
     dev->common.close = openssl_close;

     dev->flags = KEYMASTER_SOFTWARE_ONLY;

     dev->generate_keypair = openssl_generate_keypair;
     dev->import_keypair = openssl_import_keypair;
     dev->get_keypair_public = openssl_get_keypair_public;
     dev->delete_keypair = NULL;
     dev->delete_all = NULL;
     dev->sign_data = openssl_sign_data;
     dev->verify_data = openssl_verify_data;

     ERR_load_crypto_strings();
     ERR_load_BIO_strings();

     *device = reinterpret_cast<hw_device_t*>(dev.release());

     return 0;
 }

 static struct hw_module_methods_t keystore_module_methods = {
     open: openssl_open,
 };

 struct keystore_module HAL_MODULE_INFO_SYM
 __attribute__ ((visibility ("default"))) = {
     common: {
         tag: HARDWARE_MODULE_TAG,
         version_major: 1,
         version_minor: 0,
         id: KEYSTORE_HARDWARE_MODULE_ID,
         name: "Keymaster OpenSSL HAL",
         author: "The Android Open Source Project",
         methods: &keystore_module_methods,
         dso: 0,
         reserved: {},
     },
 };
	/*
	* Copyright (C) 2012 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	#include <errno.h>
	#include <string.h>
	#include <stdint.h>

	#include <keystore/keystore.h>

	#include <hardware/hardware.h>
	#include <hardware/keymaster.h>

	#include <openssl/evp.h>
	#include <openssl/bio.h>
	#include <openssl/rsa.h>
	#include <openssl/err.h>
	#include <openssl/x509.h>

	#include <utils/UniquePtr.h>

	// For debugging
	//#define LOG_NDEBUG 0

	#define LOG_TAG "OpenSSLKeyMaster"
	#include <cutils/log.h>

	struct BIGNUM_Delete {
	void operator()(BIGNUM* p) const {
	BN_free(p);
	}
	};
	typedef UniquePtr<BIGNUM, BIGNUM_Delete> Unique_BIGNUM;

	struct EVP_PKEY_Delete {
	void operator()(EVP_PKEY* p) const {
	EVP_PKEY_free(p);
	}
	};
	typedef UniquePtr<EVP_PKEY, EVP_PKEY_Delete> Unique_EVP_PKEY;

	struct PKCS8_PRIV_KEY_INFO_Delete {
	void operator()(PKCS8_PRIV_KEY_INFO* p) const {
	PKCS8_PRIV_KEY_INFO_free(p);
	}
	};
	typedef UniquePtr<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_Delete> Unique_PKCS8_PRIV_KEY_INFO;

	struct RSA_Delete {
	void operator()(RSA* p) const {
	RSA_free(p);
	}
	};
	typedef UniquePtr<RSA, RSA_Delete> Unique_RSA;

	typedef UniquePtr<keymaster_device_t> Unique_keymaster_device_t;

	/**
	* 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()


	/*
	* Checks this thread's OpenSSL error queue and logs if
	* necessary.
	*/
	static void logOpenSSLError(const char* location) {
	int error = ERR_get_error();

	if (error != 0) {
	char message[256];
	ERR_error_string_n(error, message, sizeof(message));
	ALOGE("OpenSSL error in %s %d: %s", location, error, message);
	}

	ERR_clear_error();
	ERR_remove_state(0);
	}

	static int wrap_key(EVP_PKEY* pkey, int type, uint8_t** keyBlob, size_t* keyBlobLength) {
	/* Find the length of each size */
	int publicLen = i2d_PublicKey(pkey, NULL);
	int privateLen = i2d_PrivateKey(pkey, NULL);

	if (privateLen <= 0 \|\| publicLen <= 0) {
	ALOGE("private or public key size was too big");
	return -1;
	}

	/* int type + int size + private key data + int size + public key data */
	*keyBlobLength = get_softkey_header_size() + sizeof(int) + sizeof(int) + privateLen
	+ sizeof(int) + publicLen;

	UniquePtr<unsigned char[]> derData(new unsigned char[*keyBlobLength]);
	if (derData.get() == NULL) {
	ALOGE("could not allocate memory for key blob");
	return -1;
	}
	unsigned char* p = derData.get();

	/* Write the magic value for software keys. */
	p = add_softkey_header(p, *keyBlobLength);

	/* Write key type to allocated buffer */
	for (int i = sizeof(int) - 1; i >= 0; i--) {
	p++ = (type >> (8i)) & 0xFF;
	}

	/* Write public key to allocated buffer */
	for (int i = sizeof(int) - 1; i >= 0; i--) {
	p++ = (publicLen >> (8i)) & 0xFF;
	}
	if (i2d_PublicKey(pkey, &p) != publicLen) {
	logOpenSSLError("wrap_key");
	return -1;
	}

	/* Write private key to allocated buffer */
	for (int i = sizeof(int) - 1; i >= 0; i--) {
	p++ = (privateLen >> (8i)) & 0xFF;
	}
	if (i2d_PrivateKey(pkey, &p) != privateLen) {
	logOpenSSLError("wrap_key");
	return -1;
	}

	*keyBlob = derData.release();

	return 0;
	}

	static EVP_PKEY* unwrap_key(const uint8_t* keyBlob, const size_t keyBlobLength) {
	long publicLen = 0;
	long privateLen = 0;
	const uint8_t* p = keyBlob;
	const uint8_t *const end = keyBlob + keyBlobLength;

	if (keyBlob == NULL) {
	ALOGE("supplied key blob was NULL");
	return NULL;
	}

	// Should be large enough for:
	// int32 magic, int32 type, int32 pubLen, char* pub, int32 privLen, char* priv
	if (keyBlobLength < (get_softkey_header_size() + sizeof(int) + sizeof(int) + 1
	+ sizeof(int) + 1)) {
	ALOGE("key blob appears to be truncated");
	return NULL;
	}

	if (!is_softkey(p, keyBlobLength)) {
	ALOGE("cannot read key; it was not made by this keymaster");
	return NULL;
	}
	p += get_softkey_header_size();

	int type = 0;
	for (size_t i = 0; i < sizeof(int); i++) {
	type = (type << 8) \| *p++;
	}

	Unique_EVP_PKEY pkey(EVP_PKEY_new());
	if (pkey.get() == NULL) {
	logOpenSSLError("unwrap_key");
	return NULL;
	}

	for (size_t i = 0; i < sizeof(int); i++) {
	publicLen = (publicLen << 8) \| *p++;
	}
	if (p + publicLen > end) {
	ALOGE("public key length encoding error: size=%ld, end=%d", publicLen, end - p);
	return NULL;
	}
	EVP_PKEY* tmp = pkey.get();
	d2i_PublicKey(type, &tmp, &p, publicLen);

	if (end - p < 2) {
	ALOGE("private key truncated");
	return NULL;
	}
	for (size_t i = 0; i < sizeof(int); i++) {
	privateLen = (privateLen << 8) \| *p++;
	}
	if (p + privateLen > end) {
	ALOGE("private key length encoding error: size=%ld, end=%d", privateLen, end - p);
	return NULL;
	}
	d2i_PrivateKey(type, &tmp, &p, privateLen);

	return pkey.release();
	}

	static int openssl_generate_keypair(const keymaster_device_t* dev,
	const keymaster_keypair_t key_type, const void* key_params,
	uint8_t** keyBlob, size_t* keyBlobLength) {
	ssize_t privateLen, publicLen;

	if (key_type != TYPE_RSA) {
	ALOGW("Unsupported key type %d", key_type);
	return -1;
	} else if (key_params == NULL) {
	ALOGW("key_params == null");
	return -1;
	}

	keymaster_rsa_keygen_params_t* rsa_params = (keymaster_rsa_keygen_params_t*) key_params;

	Unique_BIGNUM bn(BN_new());
	if (bn.get() == NULL) {
	logOpenSSLError("openssl_generate_keypair");
	return -1;
	}

	if (BN_set_word(bn.get(), rsa_params->public_exponent) == 0) {
	logOpenSSLError("openssl_generate_keypair");
	return -1;
	}

	/* initialize RSA */
	Unique_RSA rsa(RSA_new());
	if (rsa.get() == NULL) {
	logOpenSSLError("openssl_generate_keypair");
	return -1;
	}

	if (!RSA_generate_key_ex(rsa.get(), rsa_params->modulus_size, bn.get(), NULL)
	\|\| RSA_check_key(rsa.get()) < 0) {
	logOpenSSLError("openssl_generate_keypair");
	return -1;
	}

	/* assign to EVP */
	Unique_EVP_PKEY pkey(EVP_PKEY_new());
	if (pkey.get() == NULL) {
	logOpenSSLError("openssl_generate_keypair");
	return -1;
	}

	if (EVP_PKEY_assign_RSA(pkey.get(), rsa.get()) == 0) {
	logOpenSSLError("openssl_generate_keypair");
	return -1;
	}
	OWNERSHIP_TRANSFERRED(rsa);

	if (wrap_key(pkey.get(), EVP_PKEY_RSA, keyBlob, keyBlobLength)) {
	return -1;
	}

	return 0;
	}

	static int openssl_import_keypair(const keymaster_device_t* dev,
	const uint8_t* key, const size_t key_length,
	uint8_t** key_blob, size_t* key_blob_length) {
	int response = -1;

	if (key == NULL) {
	ALOGW("input key == NULL");
	return -1;
	} else if (key_blob == NULL \|\| key_blob_length == NULL) {
	ALOGW("output key blob or length == NULL");
	return -1;
	}

	Unique_PKCS8_PRIV_KEY_INFO pkcs8(d2i_PKCS8_PRIV_KEY_INFO(NULL, &key, key_length));
	if (pkcs8.get() == NULL) {
	logOpenSSLError("openssl_import_keypair");
	return -1;
	}

	/* assign to EVP */
	Unique_EVP_PKEY pkey(EVP_PKCS82PKEY(pkcs8.get()));
	if (pkey.get() == NULL) {
	logOpenSSLError("openssl_import_keypair");
	return -1;
	}
	OWNERSHIP_TRANSFERRED(pkcs8);

	if (wrap_key(pkey.get(), EVP_PKEY_type(pkey->type), key_blob, key_blob_length)) {
	return -1;
	}

	return 0;
	}

	static int openssl_get_keypair_public(const struct keymaster_device* dev,
	const uint8_t* key_blob, const size_t key_blob_length,
	uint8_t** x509_data, size_t* x509_data_length) {

	if (x509_data == NULL \|\| x509_data_length == NULL) {
	ALOGW("output public key buffer == NULL");
	return -1;
	}

	Unique_EVP_PKEY pkey(unwrap_key(key_blob, key_blob_length));
	if (pkey.get() == NULL) {
	return -1;
	}

	int len = i2d_PUBKEY(pkey.get(), NULL);
	if (len <= 0) {
	logOpenSSLError("openssl_get_keypair_public");
	return -1;
	}

	UniquePtr<uint8_t> key(static_cast<uint8_t*>(malloc(len)));
	if (key.get() == NULL) {
	ALOGE("Could not allocate memory for public key data");
	return -1;
	}

	unsigned char* tmp = reinterpret_cast<unsigned char*>(key.get());
	if (i2d_PUBKEY(pkey.get(), &tmp) != len) {
	logOpenSSLError("openssl_get_keypair_public");
	return -1;
	}

	ALOGV("Length of x509 data is %d", len);
	*x509_data_length = len;
	*x509_data = key.release();

	return 0;
	}

	static int openssl_sign_data(const keymaster_device_t* dev,
	const void* params,
	const uint8_t* keyBlob, const size_t keyBlobLength,
	const uint8_t* data, const size_t dataLength,
	uint8_t** signedData, size_t* signedDataLength) {

	int result = -1;
	EVP_MD_CTX ctx;
	size_t maxSize;

	if (data == NULL) {
	ALOGW("input data to sign == NULL");
	return -1;
	} else if (signedData == NULL \|\| signedDataLength == NULL) {
	ALOGW("output signature buffer == NULL");
	return -1;
	}

	Unique_EVP_PKEY pkey(unwrap_key(keyBlob, keyBlobLength));
	if (pkey.get() == NULL) {
	return -1;
	}

	if (EVP_PKEY_type(pkey->type) != EVP_PKEY_RSA) {
	ALOGW("Cannot handle non-RSA keys yet");
	return -1;
	}

	keymaster_rsa_sign_params_t* sign_params = (keymaster_rsa_sign_params_t*) params;
	if (sign_params->digest_type != DIGEST_NONE) {
	ALOGW("Cannot handle digest type %d", sign_params->digest_type);
	return -1;
	} else if (sign_params->padding_type != PADDING_NONE) {
	ALOGW("Cannot handle padding type %d", sign_params->padding_type);
	return -1;
	}

	Unique_RSA rsa(EVP_PKEY_get1_RSA(pkey.get()));
	if (rsa.get() == NULL) {
	logOpenSSLError("openssl_sign_data");
	return -1;
	}

	UniquePtr<uint8_t> signedDataPtr(reinterpret_cast<uint8_t*>(malloc(dataLength)));
	if (signedDataPtr.get() == NULL) {
	logOpenSSLError("openssl_sign_data");
	return -1;
	}

	unsigned char* tmp = reinterpret_cast<unsigned char*>(signedDataPtr.get());
	if (RSA_private_encrypt(dataLength, data, tmp, rsa.get(), RSA_NO_PADDING) <= 0) {
	logOpenSSLError("openssl_sign_data");
	return -1;
	}

	*signedDataLength = dataLength;
	*signedData = signedDataPtr.release();
	return 0;
	}

	static int openssl_verify_data(const keymaster_device_t* dev,
	const void* params,
	const uint8_t* keyBlob, const size_t keyBlobLength,
	const uint8_t* signedData, const size_t signedDataLength,
	const uint8_t* signature, const size_t signatureLength) {

	if (signedData == NULL \|\| signature == NULL) {
	ALOGW("data or signature buffers == NULL");
	return -1;
	}

	Unique_EVP_PKEY pkey(unwrap_key(keyBlob, keyBlobLength));
	if (pkey.get() == NULL) {
	return -1;
	}

	if (EVP_PKEY_type(pkey->type) != EVP_PKEY_RSA) {
	ALOGW("Cannot handle non-RSA keys yet");
	return -1;
	}

	keymaster_rsa_sign_params_t* sign_params = (keymaster_rsa_sign_params_t*) params;
	if (sign_params->digest_type != DIGEST_NONE) {
	ALOGW("Cannot handle digest type %d", sign_params->digest_type);
	return -1;
	} else if (sign_params->padding_type != PADDING_NONE) {
	ALOGW("Cannot handle padding type %d", sign_params->padding_type);
	return -1;
	} else if (signatureLength != signedDataLength) {
	ALOGW("signed data length must be signature length");
	return -1;
	}

	Unique_RSA rsa(EVP_PKEY_get1_RSA(pkey.get()));
	if (rsa.get() == NULL) {
	logOpenSSLError("openssl_verify_data");
	return -1;
	}

	UniquePtr<uint8_t> dataPtr(reinterpret_cast<uint8_t*>(malloc(signedDataLength)));
	if (dataPtr.get() == NULL) {
	logOpenSSLError("openssl_verify_data");
	return -1;
	}

	unsigned char* tmp = reinterpret_cast<unsigned char*>(dataPtr.get());
	if (!RSA_public_decrypt(signatureLength, signature, tmp, rsa.get(), RSA_NO_PADDING)) {
	logOpenSSLError("openssl_verify_data");
	return -1;
	}

	int result = 0;
	for (size_t i = 0; i < signedDataLength; i++) {
	result \|= tmp[i] ^ signedData[i];
	}

	return result == 0 ? 0 : -1;
	}

	/* Close an opened OpenSSL instance */
	static int openssl_close(hw_device_t *dev) {
	free(dev);
	return 0;
	}

	/*
	* Generic device handling
	*/
	static int openssl_open(const hw_module_t* module, const char* name,
	hw_device_t** device) {
	if (strcmp(name, KEYSTORE_KEYMASTER) != 0)
	return -EINVAL;

	Unique_keymaster_device_t dev(new keymaster_device_t);
	if (dev.get() == NULL)
	return -ENOMEM;

	dev->common.tag = HARDWARE_DEVICE_TAG;
	dev->common.version = 1;
	dev->common.module = (struct hw_module_t*) module;
	dev->common.close = openssl_close;

	dev->flags = KEYMASTER_SOFTWARE_ONLY;

	dev->generate_keypair = openssl_generate_keypair;
	dev->import_keypair = openssl_import_keypair;
	dev->get_keypair_public = openssl_get_keypair_public;
	dev->delete_keypair = NULL;
	dev->delete_all = NULL;
	dev->sign_data = openssl_sign_data;
	dev->verify_data = openssl_verify_data;

	ERR_load_crypto_strings();
	ERR_load_BIO_strings();

	device = reinterpret_cast<hw_device_t>(dev.release());

	return 0;
	}

	static struct hw_module_methods_t keystore_module_methods = {
	open: openssl_open,
	};

	struct keystore_module HAL_MODULE_INFO_SYM
	__attribute__ ((visibility ("default"))) = {
	common: {
	tag: HARDWARE_MODULE_TAG,
	version_major: 1,
	version_minor: 0,
	id: KEYSTORE_HARDWARE_MODULE_ID,
	name: "Keymaster OpenSSL HAL",
	author: "The Android Open Source Project",
	methods: &keystore_module_methods,
	dso: 0,
	reserved: {},
	},
	};