crypto/ext4crypt/ext4_crypt.cpp - android_bootable_recovery - Gitiles

 /*
  * Copyright (C) 2015 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.
  */

 /* TWRP NOTE: Kanged from system/extras/ext4_utils/ext4_crypt.cpp
  * because policy_to_hex, e4crypt_policy_set, and e4crypt_policy_get
  * are not exposed to be used. There was also a bug in e4crypt_policy_get
  * that may or may not be fixed in the user's local repo:
  * https://android.googlesource.com/platform/system/extras/+/30b93dd5715abcabd621235733733c0503f9c552
  */

 #include "ext4_crypt.h"
 #include "ext4crypt_tar.h"

 #include <dirent.h>
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>

 #include <fcntl.h>
 #include <asm/ioctl.h>
 #include <sys/syscall.h>
 #include <sys/stat.h>
 #include <sys/types.h>

 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <cutils/properties.h>

 #define XATTR_NAME_ENCRYPTION_POLICY "encryption.policy"
 #define EXT4_KEYREF_DELIMITER ((char)'.')

 #define EXT4_ENCRYPTION_MODE_AES_256_XTS    1
 #define EXT4_ENCRYPTION_MODE_AES_256_CTS    4
 #define EXT4_ENCRYPTION_MODE_AES_256_HEH    126
 #define EXT4_ENCRYPTION_MODE_PRIVATE        127

 static int encryption_mode = EXT4_ENCRYPTION_MODE_PRIVATE;

 #define HEX_LOOKUP "0123456789abcdef"

 extern "C" void policy_to_hex(const char* policy, char* hex) {
     for (size_t i = 0, j = 0; i < EXT4_KEY_DESCRIPTOR_SIZE; i++) {
         hex[j++] = HEX_LOOKUP[(policy[i] & 0xF0) >> 4];
         hex[j++] = HEX_LOOKUP[policy[i] & 0x0F];
     }
     hex[EXT4_KEY_DESCRIPTOR_SIZE_HEX - 1] = '\0';
 }

 extern "C" bool e4crypt_policy_set(const char *directory, const char *policy,
                                size_t policy_length, int contents_encryption_mode) {
     if (contents_encryption_mode == 0)
         contents_encryption_mode = encryption_mode;
     if (policy_length != EXT4_KEY_DESCRIPTOR_SIZE) {
 		printf("policy wrong length\n");
         LOG(ERROR) << "Policy wrong length: " << policy_length;
         return false;
     }
     int fd = open(directory, O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
     if (fd == -1) {
 		printf("failed to open %s\n", directory);
         PLOG(ERROR) << "Failed to open directory " << directory;
         return false;
     }

     ext4_encryption_policy eep;
     eep.version = 0;
     eep.contents_encryption_mode = contents_encryption_mode;
     eep.filenames_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_CTS;
     eep.flags = 0;
     memcpy(eep.master_key_descriptor, policy, EXT4_KEY_DESCRIPTOR_SIZE);
     if (ioctl(fd, EXT4_IOC_SET_ENCRYPTION_POLICY, &eep)) {
 		printf("failed to set policy for '%s' '%s'\n", directory, policy);
         PLOG(ERROR) << "Failed to set encryption policy for " << directory;
         close(fd);
         return false;
     }
     close(fd);

     char policy_hex[EXT4_KEY_DESCRIPTOR_SIZE_HEX];
     policy_to_hex(policy, policy_hex);
     LOG(INFO) << "Policy for " << directory << " set to " << policy_hex;
     return true;
 }

 extern "C" bool e4crypt_policy_get(const char *directory, char *policy,
                                size_t policy_length, int contents_encryption_mode) {
     if (contents_encryption_mode == 0)
         contents_encryption_mode = encryption_mode;
     if (policy_length != EXT4_KEY_DESCRIPTOR_SIZE) {
         LOG(ERROR) << "Policy wrong length: " << policy_length;
         return false;
     }

     int fd = open(directory, O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
     if (fd == -1) {
         PLOG(ERROR) << "Failed to open directory " << directory;
         return false;
     }

     ext4_encryption_policy eep;
     memset(&eep, 0, sizeof(ext4_encryption_policy));
     if (ioctl(fd, EXT4_IOC_GET_ENCRYPTION_POLICY, &eep) != 0) {
         PLOG(ERROR) << "Failed to get encryption policy for " << directory;
         close(fd);
         return false;
     }
     close(fd);

     if ((eep.version != 0)
             || (eep.contents_encryption_mode != contents_encryption_mode)
             || (eep.filenames_encryption_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS)
             || (eep.flags != 0)) {
         LOG(ERROR) << "Failed to find matching encryption policy for " << directory;
         return false;
     }
     memcpy(policy, eep.master_key_descriptor, EXT4_KEY_DESCRIPTOR_SIZE);

     return true;
 }

 extern "C" void e4crypt_policy_fill_default_struct(ext4_encryption_policy *eep) {
 	eep->version = 0;
     eep->contents_encryption_mode = encryption_mode;
     eep->filenames_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_CTS;
     eep->flags = 0;
     memset((void*)&eep->master_key_descriptor[0], 0, EXT4_KEY_DESCRIPTOR_SIZE);
 }

 extern "C" bool e4crypt_policy_set_struct(const char *directory, const ext4_encryption_policy *eep) {
     int fd = open(directory, O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
     if (fd == -1) {
 		printf("failed to open %s\n", directory);
         PLOG(ERROR) << "Failed to open directory " << directory;
         return false;
     }
     if (ioctl(fd, EXT4_IOC_SET_ENCRYPTION_POLICY, eep)) {
 		printf("failed to set policy for '%s'\n", directory);
         PLOG(ERROR) << "Failed to set encryption policy for " << directory;
         close(fd);
         return false;
     }
     close(fd);
     return true;
 }

 extern "C" bool e4crypt_policy_get_struct(const char *directory, ext4_encryption_policy *eep) {
     int fd = open(directory, O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
     if (fd == -1) {
         printf("Failed to open '%s'\n", directory);
         PLOG(ERROR) << "Failed to open directory " << directory;
         return false;
     }
     memset(eep, 0, sizeof(ext4_encryption_policy));
     if (ioctl(fd, EXT4_IOC_GET_ENCRYPTION_POLICY, eep) != 0) {
         PLOG(ERROR) << "Failed to get encryption policy for " << directory;
         close(fd);
         return false;
     }
     close(fd);
     return true;
 }

 extern "C" bool e4crypt_set_mode() {
     const char* mode_file = "/data/unencrypted/mode";
     struct stat st;
     if (stat(mode_file, &st) != 0 || st.st_size <= 0) {
         printf("Invalid encryption mode file %s\n", mode_file);
         return false;
     }
     size_t mode_size = st.st_size;
     char contents_encryption_mode[mode_size + 1];
     memset((void*)contents_encryption_mode, 0, mode_size + 1);
     int fd = open(mode_file, O_RDONLY);
     if (fd < 0) {
         printf("error opening '%s': %s\n", mode_file, strerror(errno));
         return false;
     }
     if (read(fd, contents_encryption_mode, mode_size) != mode_size) {
         printf("read error on '%s': %s\n", mode_file, strerror(errno));
         close(fd);
         return false;
     }
     close(fd);
     if (!strcmp(contents_encryption_mode, "software")) {
         encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
     } else if (!strcmp(contents_encryption_mode, "ice")) {
         encryption_mode = EXT4_ENCRYPTION_MODE_PRIVATE;
     } else {
         printf("Invalid encryption mode '%s'\n", contents_encryption_mode);
         return false;
     }
     printf("set encryption mode to %i\n", encryption_mode);
     return true;
 }
	/*
	* Copyright (C) 2015 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.
	*/

	/* TWRP NOTE: Kanged from system/extras/ext4_utils/ext4_crypt.cpp
	* because policy_to_hex, e4crypt_policy_set, and e4crypt_policy_get
	* are not exposed to be used. There was also a bug in e4crypt_policy_get
	* that may or may not be fixed in the user's local repo:
	* https://android.googlesource.com/platform/system/extras/+/30b93dd5715abcabd621235733733c0503f9c552
	*/

	#include "ext4_crypt.h"
	#include "ext4crypt_tar.h"

	#include <dirent.h>
	#include <errno.h>
	#include <string.h>
	#include <unistd.h>

	#include <fcntl.h>
	#include <asm/ioctl.h>
	#include <sys/syscall.h>
	#include <sys/stat.h>
	#include <sys/types.h>

	#include <android-base/file.h>
	#include <android-base/logging.h>
	#include <cutils/properties.h>

	#define XATTR_NAME_ENCRYPTION_POLICY "encryption.policy"
	#define EXT4_KEYREF_DELIMITER ((char)'.')

	#define EXT4_ENCRYPTION_MODE_AES_256_XTS 1
	#define EXT4_ENCRYPTION_MODE_AES_256_CTS 4
	#define EXT4_ENCRYPTION_MODE_AES_256_HEH 126
	#define EXT4_ENCRYPTION_MODE_PRIVATE 127

	static int encryption_mode = EXT4_ENCRYPTION_MODE_PRIVATE;

	#define HEX_LOOKUP "0123456789abcdef"

	extern "C" void policy_to_hex(const char* policy, char* hex) {
	for (size_t i = 0, j = 0; i < EXT4_KEY_DESCRIPTOR_SIZE; i++) {
	hex[j++] = HEX_LOOKUP[(policy[i] & 0xF0) >> 4];
	hex[j++] = HEX_LOOKUP[policy[i] & 0x0F];
	}
	hex[EXT4_KEY_DESCRIPTOR_SIZE_HEX - 1] = '\0';
	}

	extern "C" bool e4crypt_policy_set(const char directory, const char policy,
	size_t policy_length, int contents_encryption_mode) {
	if (contents_encryption_mode == 0)
	contents_encryption_mode = encryption_mode;
	if (policy_length != EXT4_KEY_DESCRIPTOR_SIZE) {
	printf("policy wrong length\n");
	LOG(ERROR) << "Policy wrong length: " << policy_length;
	return false;
	}
	int fd = open(directory, O_DIRECTORY \| O_NOFOLLOW \| O_CLOEXEC);
	if (fd == -1) {
	printf("failed to open %s\n", directory);
	PLOG(ERROR) << "Failed to open directory " << directory;
	return false;
	}

	ext4_encryption_policy eep;
	eep.version = 0;
	eep.contents_encryption_mode = contents_encryption_mode;
	eep.filenames_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_CTS;
	eep.flags = 0;
	memcpy(eep.master_key_descriptor, policy, EXT4_KEY_DESCRIPTOR_SIZE);
	if (ioctl(fd, EXT4_IOC_SET_ENCRYPTION_POLICY, &eep)) {
	printf("failed to set policy for '%s' '%s'\n", directory, policy);
	PLOG(ERROR) << "Failed to set encryption policy for " << directory;
	close(fd);
	return false;
	}
	close(fd);

	char policy_hex[EXT4_KEY_DESCRIPTOR_SIZE_HEX];
	policy_to_hex(policy, policy_hex);
	LOG(INFO) << "Policy for " << directory << " set to " << policy_hex;
	return true;
	}

	extern "C" bool e4crypt_policy_get(const char directory, char policy,
	size_t policy_length, int contents_encryption_mode) {
	if (contents_encryption_mode == 0)
	contents_encryption_mode = encryption_mode;
	if (policy_length != EXT4_KEY_DESCRIPTOR_SIZE) {
	LOG(ERROR) << "Policy wrong length: " << policy_length;
	return false;
	}

	int fd = open(directory, O_DIRECTORY \| O_NOFOLLOW \| O_CLOEXEC);
	if (fd == -1) {
	PLOG(ERROR) << "Failed to open directory " << directory;
	return false;
	}

	ext4_encryption_policy eep;
	memset(&eep, 0, sizeof(ext4_encryption_policy));
	if (ioctl(fd, EXT4_IOC_GET_ENCRYPTION_POLICY, &eep) != 0) {
	PLOG(ERROR) << "Failed to get encryption policy for " << directory;
	close(fd);
	return false;
	}
	close(fd);

	if ((eep.version != 0)
	\|\| (eep.contents_encryption_mode != contents_encryption_mode)
	\|\| (eep.filenames_encryption_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS)
	\|\| (eep.flags != 0)) {
	LOG(ERROR) << "Failed to find matching encryption policy for " << directory;
	return false;
	}
	memcpy(policy, eep.master_key_descriptor, EXT4_KEY_DESCRIPTOR_SIZE);

	return true;
	}

	extern "C" void e4crypt_policy_fill_default_struct(ext4_encryption_policy *eep) {
	eep->version = 0;
	eep->contents_encryption_mode = encryption_mode;
	eep->filenames_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_CTS;
	eep->flags = 0;
	memset((void*)&eep->master_key_descriptor[0], 0, EXT4_KEY_DESCRIPTOR_SIZE);
	}

	extern "C" bool e4crypt_policy_set_struct(const char directory, const ext4_encryption_policy eep) {
	int fd = open(directory, O_DIRECTORY \| O_NOFOLLOW \| O_CLOEXEC);
	if (fd == -1) {
	printf("failed to open %s\n", directory);
	PLOG(ERROR) << "Failed to open directory " << directory;
	return false;
	}
	if (ioctl(fd, EXT4_IOC_SET_ENCRYPTION_POLICY, eep)) {
	printf("failed to set policy for '%s'\n", directory);
	PLOG(ERROR) << "Failed to set encryption policy for " << directory;
	close(fd);
	return false;
	}
	close(fd);
	return true;
	}

	extern "C" bool e4crypt_policy_get_struct(const char directory, ext4_encryption_policy eep) {
	int fd = open(directory, O_DIRECTORY \| O_NOFOLLOW \| O_CLOEXEC);
	if (fd == -1) {
	printf("Failed to open '%s'\n", directory);
	PLOG(ERROR) << "Failed to open directory " << directory;
	return false;
	}
	memset(eep, 0, sizeof(ext4_encryption_policy));
	if (ioctl(fd, EXT4_IOC_GET_ENCRYPTION_POLICY, eep) != 0) {
	PLOG(ERROR) << "Failed to get encryption policy for " << directory;
	close(fd);
	return false;
	}
	close(fd);
	return true;
	}

	extern "C" bool e4crypt_set_mode() {
	const char* mode_file = "/data/unencrypted/mode";
	struct stat st;
	if (stat(mode_file, &st) != 0 \|\| st.st_size <= 0) {
	printf("Invalid encryption mode file %s\n", mode_file);
	return false;
	}
	size_t mode_size = st.st_size;
	char contents_encryption_mode[mode_size + 1];
	memset((void*)contents_encryption_mode, 0, mode_size + 1);
	int fd = open(mode_file, O_RDONLY);
	if (fd < 0) {
	printf("error opening '%s': %s\n", mode_file, strerror(errno));
	return false;
	}
	if (read(fd, contents_encryption_mode, mode_size) != mode_size) {
	printf("read error on '%s': %s\n", mode_file, strerror(errno));
	close(fd);
	return false;
	}
	close(fd);
	if (!strcmp(contents_encryption_mode, "software")) {
	encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
	} else if (!strcmp(contents_encryption_mode, "ice")) {
	encryption_mode = EXT4_ENCRYPTION_MODE_PRIVATE;
	} else {
	printf("Invalid encryption mode '%s'\n", contents_encryption_mode);
	return false;
	}
	printf("set encryption mode to %i\n", encryption_mode);
	return true;
	}