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rocksdb/env/env_encryption.cc

1257 lines
46 KiB

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#ifndef ROCKSDB_LITE
#include "rocksdb/env_encryption.h"
#include <algorithm>
#include <cassert>
#include <cctype>
#include <iostream>
#include "env/composite_env_wrapper.h"
#include "env/env_encryption_ctr.h"
#include "monitoring/perf_context_imp.h"
#include "rocksdb/convenience.h"
#include "rocksdb/io_status.h"
#include "rocksdb/system_clock.h"
#include "util/aligned_buffer.h"
#include "util/coding.h"
#include "util/random.h"
#include "util/string_util.h"
#endif
namespace ROCKSDB_NAMESPACE {
#ifndef ROCKSDB_LITE
static constexpr char kROT13CipherName[] = "ROT13";
static constexpr char kCTRProviderName[] = "CTR";
Status BlockCipher::CreateFromString(const ConfigOptions& /*config_options*/,
const std::string& value,
std::shared_ptr<BlockCipher>* result) {
std::string id = value;
size_t colon = value.find(':');
if (colon != std::string::npos) {
id = value.substr(0, colon);
}
if (id == kROT13CipherName) {
if (colon != std::string::npos) {
size_t block_size = ParseSizeT(value.substr(colon + 1));
result->reset(new ROT13BlockCipher(block_size));
} else {
result->reset(new ROT13BlockCipher(32));
}
return Status::OK();
} else {
return Status::NotSupported("Could not find cipher ", value);
}
}
Status EncryptionProvider::CreateFromString(
const ConfigOptions& /*config_options*/, const std::string& value,
std::shared_ptr<EncryptionProvider>* result) {
std::string id = value;
bool is_test = StartsWith(value, "test://");
Status status = Status::OK();
if (is_test) {
id = value.substr(strlen("test://"));
}
if (id == kCTRProviderName) {
result->reset(new CTREncryptionProvider());
} else if (is_test) {
result->reset(new CTREncryptionProvider());
} else {
return Status::NotSupported("Could not find provider ", value);
}
if (status.ok() && is_test) {
status = result->get()->TEST_Initialize();
}
return status;
}
std::shared_ptr<EncryptionProvider> EncryptionProvider::NewCTRProvider(
const std::shared_ptr<BlockCipher>& cipher) {
return std::make_shared<CTREncryptionProvider>(cipher);
}
// Read up to "n" bytes from the file. "scratch[0..n-1]" may be
// written by this routine. Sets "*result" to the data that was
// read (including if fewer than "n" bytes were successfully read).
// May set "*result" to point at data in "scratch[0..n-1]", so
// "scratch[0..n-1]" must be live when "*result" is used.
// If an error was encountered, returns a non-OK status.
//
// REQUIRES: External synchronization
IOStatus EncryptedSequentialFile::Read(size_t n, const IOOptions& options,
Slice* result, char* scratch,
IODebugContext* dbg) {
assert(scratch);
IOStatus io_s = file_->Read(n, options, result, scratch, dbg);
if (!io_s.ok()) {
return io_s;
}
{
PERF_TIMER_GUARD(decrypt_data_nanos);
io_s = status_to_io_status(
stream_->Decrypt(offset_, (char*)result->data(), result->size()));
}
if (io_s.ok()) {
offset_ += result->size(); // We've already ready data from disk, so update
// offset_ even if decryption fails.
}
return io_s;
}
// Skip "n" bytes from the file. This is guaranteed to be no
// slower that reading the same data, but may be faster.
//
// If end of file is reached, skipping will stop at the end of the
// file, and Skip will return OK.
//
// REQUIRES: External synchronization
IOStatus EncryptedSequentialFile::Skip(uint64_t n) {
auto status = file_->Skip(n);
if (!status.ok()) {
return status;
}
offset_ += n;
return status;
}
// Indicates the upper layers if the current SequentialFile implementation
// uses direct IO.
bool EncryptedSequentialFile::use_direct_io() const {
return file_->use_direct_io();
}
// Use the returned alignment value to allocate
// aligned buffer for Direct I/O
size_t EncryptedSequentialFile::GetRequiredBufferAlignment() const {
return file_->GetRequiredBufferAlignment();
}
// Remove any kind of caching of data from the offset to offset+length
// of this file. If the length is 0, then it refers to the end of file.
// If the system is not caching the file contents, then this is a noop.
IOStatus EncryptedSequentialFile::InvalidateCache(size_t offset,
size_t length) {
return file_->InvalidateCache(offset + prefixLength_, length);
}
// Positioned Read for direct I/O
// If Direct I/O enabled, offset, n, and scratch should be properly aligned
IOStatus EncryptedSequentialFile::PositionedRead(uint64_t offset, size_t n,
const IOOptions& options,
Slice* result, char* scratch,
IODebugContext* dbg) {
assert(scratch);
offset += prefixLength_; // Skip prefix
auto io_s = file_->PositionedRead(offset, n, options, result, scratch, dbg);
if (!io_s.ok()) {
return io_s;
}
offset_ = offset + result->size();
{
PERF_TIMER_GUARD(decrypt_data_nanos);
io_s = status_to_io_status(
stream_->Decrypt(offset, (char*)result->data(), result->size()));
}
return io_s;
}
// Read up to "n" bytes from the file starting at "offset".
// "scratch[0..n-1]" may be written by this routine. Sets "*result"
// to the data that was read (including if fewer than "n" bytes were
// successfully read). May set "*result" to point at data in
// "scratch[0..n-1]", so "scratch[0..n-1]" must be live when
// "*result" is used. If an error was encountered, returns a non-OK
// status.
//
// Safe for concurrent use by multiple threads.
// If Direct I/O enabled, offset, n, and scratch should be aligned properly.
IOStatus EncryptedRandomAccessFile::Read(uint64_t offset, size_t n,
const IOOptions& options,
Slice* result, char* scratch,
IODebugContext* dbg) const {
assert(scratch);
offset += prefixLength_;
auto io_s = file_->Read(offset, n, options, result, scratch, dbg);
if (!io_s.ok()) {
return io_s;
}
{
PERF_TIMER_GUARD(decrypt_data_nanos);
io_s = status_to_io_status(
stream_->Decrypt(offset, (char*)result->data(), result->size()));
}
return io_s;
}
// Readahead the file starting from offset by n bytes for caching.
IOStatus EncryptedRandomAccessFile::Prefetch(uint64_t offset, size_t n,
const IOOptions& options,
IODebugContext* dbg) {
// return Status::OK();
return file_->Prefetch(offset + prefixLength_, n, options, dbg);
}
// Tries to get an unique ID for this file that will be the same each time
// the file is opened (and will stay the same while the file is open).
// Furthermore, it tries to make this ID at most "max_size" bytes. If such an
// ID can be created this function returns the length of the ID and places it
// in "id"; otherwise, this function returns 0, in which case "id"
// may not have been modified.
//
// This function guarantees, for IDs from a given environment, two unique ids
// cannot be made equal to each other by adding arbitrary bytes to one of
// them. That is, no unique ID is the prefix of another.
//
// This function guarantees that the returned ID will not be interpretable as
// a single varint.
//
// Note: these IDs are only valid for the duration of the process.
size_t EncryptedRandomAccessFile::GetUniqueId(char* id, size_t max_size) const {
return file_->GetUniqueId(id, max_size);
};
void EncryptedRandomAccessFile::Hint(AccessPattern pattern) {
file_->Hint(pattern);
}
// Indicates the upper layers if the current RandomAccessFile implementation
// uses direct IO.
bool EncryptedRandomAccessFile::use_direct_io() const {
return file_->use_direct_io();
}
// Use the returned alignment value to allocate
// aligned buffer for Direct I/O
size_t EncryptedRandomAccessFile::GetRequiredBufferAlignment() const {
return file_->GetRequiredBufferAlignment();
}
// Remove any kind of caching of data from the offset to offset+length
// of this file. If the length is 0, then it refers to the end of file.
// If the system is not caching the file contents, then this is a noop.
IOStatus EncryptedRandomAccessFile::InvalidateCache(size_t offset,
size_t length) {
return file_->InvalidateCache(offset + prefixLength_, length);
}
// A file abstraction for sequential writing. The implementation
// must provide buffering since callers may append small fragments
// at a time to the file.
IOStatus EncryptedWritableFile::Append(const Slice& data,
const IOOptions& options,
IODebugContext* dbg) {
AlignedBuffer buf;
Slice dataToAppend(data);
if (data.size() > 0) {
auto offset = file_->GetFileSize(options, dbg); // size including prefix
// Encrypt in cloned buffer
buf.Alignment(GetRequiredBufferAlignment());
buf.AllocateNewBuffer(data.size());
// TODO (sagar0): Modify AlignedBuffer.Append to allow doing a memmove
// so that the next two lines can be replaced with buf.Append().
memmove(buf.BufferStart(), data.data(), data.size());
buf.Size(data.size());
IOStatus io_s;
{
PERF_TIMER_GUARD(encrypt_data_nanos);
io_s = status_to_io_status(
stream_->Encrypt(offset, buf.BufferStart(), buf.CurrentSize()));
}
if (!io_s.ok()) {
return io_s;
}
dataToAppend = Slice(buf.BufferStart(), buf.CurrentSize());
}
return file_->Append(dataToAppend, options, dbg);
}
IOStatus EncryptedWritableFile::PositionedAppend(const Slice& data,
uint64_t offset,
const IOOptions& options,
IODebugContext* dbg) {
AlignedBuffer buf;
Slice dataToAppend(data);
offset += prefixLength_;
if (data.size() > 0) {
// Encrypt in cloned buffer
buf.Alignment(GetRequiredBufferAlignment());
buf.AllocateNewBuffer(data.size());
memmove(buf.BufferStart(), data.data(), data.size());
buf.Size(data.size());
IOStatus io_s;
{
PERF_TIMER_GUARD(encrypt_data_nanos);
io_s = status_to_io_status(
stream_->Encrypt(offset, buf.BufferStart(), buf.CurrentSize()));
}
if (!io_s.ok()) {
return io_s;
}
dataToAppend = Slice(buf.BufferStart(), buf.CurrentSize());
}
return file_->PositionedAppend(dataToAppend, offset, options, dbg);
}
// Indicates the upper layers if the current WritableFile implementation
// uses direct IO.
bool EncryptedWritableFile::use_direct_io() const {
return file_->use_direct_io();
}
// Use the returned alignment value to allocate
// aligned buffer for Direct I/O
size_t EncryptedWritableFile::GetRequiredBufferAlignment() const {
return file_->GetRequiredBufferAlignment();
}
/*
* Get the size of valid data in the file.
*/
uint64_t EncryptedWritableFile::GetFileSize(const IOOptions& options,
IODebugContext* dbg) {
return file_->GetFileSize(options, dbg) - prefixLength_;
}
// Truncate is necessary to trim the file to the correct size
// before closing. It is not always possible to keep track of the file
// size due to whole pages writes. The behavior is undefined if called
// with other writes to follow.
IOStatus EncryptedWritableFile::Truncate(uint64_t size,
const IOOptions& options,
IODebugContext* dbg) {
return file_->Truncate(size + prefixLength_, options, dbg);
}
// Remove any kind of caching of data from the offset to offset+length
// of this file. If the length is 0, then it refers to the end of file.
// If the system is not caching the file contents, then this is a noop.
// This call has no effect on dirty pages in the cache.
IOStatus EncryptedWritableFile::InvalidateCache(size_t offset, size_t length) {
return file_->InvalidateCache(offset + prefixLength_, length);
}
// Sync a file range with disk.
// offset is the starting byte of the file range to be synchronized.
// nbytes specifies the length of the range to be synchronized.
// This asks the OS to initiate flushing the cached data to disk,
// without waiting for completion.
// Default implementation does nothing.
IOStatus EncryptedWritableFile::RangeSync(uint64_t offset, uint64_t nbytes,
const IOOptions& options,
IODebugContext* dbg) {
return file_->RangeSync(offset + prefixLength_, nbytes, options, dbg);
}
// PrepareWrite performs any necessary preparation for a write
// before the write actually occurs. This allows for pre-allocation
// of space on devices where it can result in less file
// fragmentation and/or less waste from over-zealous filesystem
// pre-allocation.
void EncryptedWritableFile::PrepareWrite(size_t offset, size_t len,
const IOOptions& options,
IODebugContext* dbg) {
file_->PrepareWrite(offset + prefixLength_, len, options, dbg);
}
void EncryptedWritableFile::SetPreallocationBlockSize(size_t size) {
// the size here doesn't need to include prefixLength_, as it's a
// configuration will be use for `PrepareWrite()`.
file_->SetPreallocationBlockSize(size);
}
void EncryptedWritableFile::GetPreallocationStatus(
size_t* block_size, size_t* last_allocated_block) {
file_->GetPreallocationStatus(block_size, last_allocated_block);
}
// Pre-allocates space for a file.
IOStatus EncryptedWritableFile::Allocate(uint64_t offset, uint64_t len,
const IOOptions& options,
IODebugContext* dbg) {
return file_->Allocate(offset + prefixLength_, len, options, dbg);
}
IOStatus EncryptedWritableFile::Flush(const IOOptions& options,
IODebugContext* dbg) {
return file_->Flush(options, dbg);
}
IOStatus EncryptedWritableFile::Sync(const IOOptions& options,
IODebugContext* dbg) {
return file_->Sync(options, dbg);
}
IOStatus EncryptedWritableFile::Close(const IOOptions& options,
IODebugContext* dbg) {
return file_->Close(options, dbg);
}
// A file abstraction for random reading and writing.
// Indicates if the class makes use of direct I/O
// If false you must pass aligned buffer to Write()
bool EncryptedRandomRWFile::use_direct_io() const {
return file_->use_direct_io();
}
// Use the returned alignment value to allocate
// aligned buffer for Direct I/O
size_t EncryptedRandomRWFile::GetRequiredBufferAlignment() const {
return file_->GetRequiredBufferAlignment();
}
// Write bytes in `data` at offset `offset`, Returns Status::OK() on success.
// Pass aligned buffer when use_direct_io() returns true.
IOStatus EncryptedRandomRWFile::Write(uint64_t offset, const Slice& data,
const IOOptions& options,
IODebugContext* dbg) {
AlignedBuffer buf;
Slice dataToWrite(data);
offset += prefixLength_;
if (data.size() > 0) {
// Encrypt in cloned buffer
buf.Alignment(GetRequiredBufferAlignment());
buf.AllocateNewBuffer(data.size());
memmove(buf.BufferStart(), data.data(), data.size());
buf.Size(data.size());
IOStatus io_s;
{
PERF_TIMER_GUARD(encrypt_data_nanos);
io_s = status_to_io_status(
stream_->Encrypt(offset, buf.BufferStart(), buf.CurrentSize()));
}
if (!io_s.ok()) {
return io_s;
}
dataToWrite = Slice(buf.BufferStart(), buf.CurrentSize());
}
return file_->Write(offset, dataToWrite, options, dbg);
}
// Read up to `n` bytes starting from offset `offset` and store them in
// result, provided `scratch` size should be at least `n`.
// Returns Status::OK() on success.
IOStatus EncryptedRandomRWFile::Read(uint64_t offset, size_t n,
const IOOptions& options, Slice* result,
char* scratch, IODebugContext* dbg) const {
assert(scratch);
offset += prefixLength_;
auto status = file_->Read(offset, n, options, result, scratch, dbg);
if (!status.ok()) {
return status;
}
{
PERF_TIMER_GUARD(decrypt_data_nanos);
status = status_to_io_status(
stream_->Decrypt(offset, (char*)result->data(), result->size()));
}
return status;
}
IOStatus EncryptedRandomRWFile::Flush(const IOOptions& options,
IODebugContext* dbg) {
return file_->Flush(options, dbg);
}
IOStatus EncryptedRandomRWFile::Sync(const IOOptions& options,
IODebugContext* dbg) {
return file_->Sync(options, dbg);
}
IOStatus EncryptedRandomRWFile::Fsync(const IOOptions& options,
IODebugContext* dbg) {
return file_->Fsync(options, dbg);
}
IOStatus EncryptedRandomRWFile::Close(const IOOptions& options,
IODebugContext* dbg) {
return file_->Close(options, dbg);
}
namespace {
// EncryptedFileSystemImpl implements an FileSystemWrapper that adds encryption
// to files stored on disk.
class EncryptedFileSystemImpl : public EncryptedFileSystem {
public:
const char* Name() const override { return "EncryptedFS"; }
// Returns the raw encryption provider that should be used to write the input
// encrypted file. If there is no such provider, NotFound is returned.
IOStatus GetWritableProvider(const std::string& /*fname*/,
EncryptionProvider** result) {
if (provider_) {
*result = provider_.get();
return IOStatus::OK();
} else {
*result = nullptr;
return IOStatus::NotFound("No WriteProvider specified");
}
}
// Returns the raw encryption provider that should be used to read the input
// encrypted file. If there is no such provider, NotFound is returned.
IOStatus GetReadableProvider(const std::string& /*fname*/,
EncryptionProvider** result) {
if (provider_) {
*result = provider_.get();
return IOStatus::OK();
} else {
*result = nullptr;
return IOStatus::NotFound("No Provider specified");
}
}
// Creates a CipherStream for the underlying file/name using the options
// If a writable provider is found and encryption is enabled, uses
// this provider to create a cipher stream.
// @param fname Name of the writable file
// @param underlying The underlying "raw" file
// @param options Options for creating the file/cipher
// @param prefix_length Returns the length of the encryption prefix used for
// this file
// @param stream Returns the cipher stream to use for this file if it
// should be encrypted
// @return OK on success, non-OK on failure.
template <class TypeFile>
IOStatus CreateWritableCipherStream(
const std::string& fname, const std::unique_ptr<TypeFile>& underlying,
const FileOptions& options, size_t* prefix_length,
std::unique_ptr<BlockAccessCipherStream>* stream, IODebugContext* dbg) {
EncryptionProvider* provider = nullptr;
*prefix_length = 0;
IOStatus status = GetWritableProvider(fname, &provider);
if (!status.ok()) {
return status;
} else if (provider != nullptr) {
// Initialize & write prefix (if needed)
AlignedBuffer buffer;
Slice prefix;
*prefix_length = provider->GetPrefixLength();
if (*prefix_length > 0) {
// Initialize prefix
buffer.Alignment(underlying->GetRequiredBufferAlignment());
buffer.AllocateNewBuffer(*prefix_length);
status = status_to_io_status(provider->CreateNewPrefix(
fname, buffer.BufferStart(), *prefix_length));
if (status.ok()) {
buffer.Size(*prefix_length);
prefix = Slice(buffer.BufferStart(), buffer.CurrentSize());
// Write prefix
status = underlying->Append(prefix, options.io_options, dbg);
}
if (!status.ok()) {
return status;
}
}
// Create cipher stream
status = status_to_io_status(
provider->CreateCipherStream(fname, options, prefix, stream));
}
return status;
}
template <class TypeFile>
IOStatus CreateWritableEncryptedFile(const std::string& fname,
std::unique_ptr<TypeFile>& underlying,
const FileOptions& options,
std::unique_ptr<TypeFile>* result,
IODebugContext* dbg) {
// Create cipher stream
std::unique_ptr<BlockAccessCipherStream> stream;
size_t prefix_length;
IOStatus status = CreateWritableCipherStream(fname, underlying, options,
&prefix_length, &stream, dbg);
if (status.ok()) {
if (stream) {
result->reset(new EncryptedWritableFile(
std::move(underlying), std::move(stream), prefix_length));
} else {
result->reset(underlying.release());
}
}
return status;
}
// Creates a CipherStream for the underlying file/name using the options
// If a writable provider is found and encryption is enabled, uses
// this provider to create a cipher stream.
// @param fname Name of the writable file
// @param underlying The underlying "raw" file
// @param options Options for creating the file/cipher
// @param prefix_length Returns the length of the encryption prefix used for
// this file
// @param stream Returns the cipher stream to use for this file if it
// should be encrypted
// @return OK on success, non-OK on failure.
template <class TypeFile>
IOStatus CreateRandomWriteCipherStream(
const std::string& fname, const std::unique_ptr<TypeFile>& underlying,
const FileOptions& options, size_t* prefix_length,
std::unique_ptr<BlockAccessCipherStream>* stream, IODebugContext* dbg) {
EncryptionProvider* provider = nullptr;
*prefix_length = 0;
IOStatus io_s = GetWritableProvider(fname, &provider);
if (!io_s.ok()) {
return io_s;
} else if (provider != nullptr) {
// Initialize & write prefix (if needed)
AlignedBuffer buffer;
Slice prefix;
*prefix_length = provider->GetPrefixLength();
if (*prefix_length > 0) {
// Initialize prefix
buffer.Alignment(underlying->GetRequiredBufferAlignment());
buffer.AllocateNewBuffer(*prefix_length);
io_s = status_to_io_status(provider->CreateNewPrefix(
fname, buffer.BufferStart(), *prefix_length));
if (io_s.ok()) {
buffer.Size(*prefix_length);
prefix = Slice(buffer.BufferStart(), buffer.CurrentSize());
// Write prefix
io_s = underlying->Write(0, prefix, options.io_options, dbg);
}
if (!io_s.ok()) {
return io_s;
}
}
// Create cipher stream
io_s = status_to_io_status(
provider->CreateCipherStream(fname, options, prefix, stream));
}
return io_s;
}
// Creates a CipherStream for the underlying file/name using the options
// If a readable provider is found and the file is encrypted, uses
// this provider to create a cipher stream.
// @param fname Name of the writable file
// @param underlying The underlying "raw" file
// @param options Options for creating the file/cipher
// @param prefix_length Returns the length of the encryption prefix used for
// this file
// @param stream Returns the cipher stream to use for this file if it
// is encrypted
// @return OK on success, non-OK on failure.
template <class TypeFile>
IOStatus CreateSequentialCipherStream(
const std::string& fname, const std::unique_ptr<TypeFile>& underlying,
const FileOptions& options, size_t* prefix_length,
std::unique_ptr<BlockAccessCipherStream>* stream, IODebugContext* dbg) {
// Read prefix (if needed)
AlignedBuffer buffer;
Slice prefix;
*prefix_length = provider_->GetPrefixLength();
if (*prefix_length > 0) {
// Read prefix
buffer.Alignment(underlying->GetRequiredBufferAlignment());
buffer.AllocateNewBuffer(*prefix_length);
IOStatus status = underlying->Read(*prefix_length, options.io_options,
&prefix, buffer.BufferStart(), dbg);
if (!status.ok()) {
return status;
}
buffer.Size(*prefix_length);
}
return status_to_io_status(
provider_->CreateCipherStream(fname, options, prefix, stream));
}
// Creates a CipherStream for the underlying file/name using the options
// If a readable provider is found and the file is encrypted, uses
// this provider to create a cipher stream.
// @param fname Name of the writable file
// @param underlying The underlying "raw" file
// @param options Options for creating the file/cipher
// @param prefix_length Returns the length of the encryption prefix used for
// this file
// @param stream Returns the cipher stream to use for this file if it
// is encrypted
// @return OK on success, non-OK on failure.
template <class TypeFile>
IOStatus CreateRandomReadCipherStream(
const std::string& fname, const std::unique_ptr<TypeFile>& underlying,
const FileOptions& options, size_t* prefix_length,
std::unique_ptr<BlockAccessCipherStream>* stream, IODebugContext* dbg) {
// Read prefix (if needed)
AlignedBuffer buffer;
Slice prefix;
*prefix_length = provider_->GetPrefixLength();
if (*prefix_length > 0) {
// Read prefix
buffer.Alignment(underlying->GetRequiredBufferAlignment());
buffer.AllocateNewBuffer(*prefix_length);
IOStatus status = underlying->Read(0, *prefix_length, options.io_options,
&prefix, buffer.BufferStart(), dbg);
if (!status.ok()) {
return status;
}
buffer.Size(*prefix_length);
}
return status_to_io_status(
provider_->CreateCipherStream(fname, options, prefix, stream));
}
public:
EncryptedFileSystemImpl(const std::shared_ptr<FileSystem>& base,
const std::shared_ptr<EncryptionProvider>& provider)
: EncryptedFileSystem(base) {
provider_ = provider;
}
Status AddCipher(const std::string& descriptor, const char* cipher,
size_t len, bool for_write) override {
return provider_->AddCipher(descriptor, cipher, len, for_write);
}
// NewSequentialFile opens a file for sequential reading.
IOStatus NewSequentialFile(const std::string& fname,
const FileOptions& options,
std::unique_ptr<FSSequentialFile>* result,
IODebugContext* dbg) override {
result->reset();
if (options.use_mmap_reads) {
return IOStatus::InvalidArgument();
}
// Open file using underlying Env implementation
std::unique_ptr<FSSequentialFile> underlying;
auto status =
FileSystemWrapper::NewSequentialFile(fname, options, &underlying, dbg);
if (!status.ok()) {
return status;
}
uint64_t file_size;
status = FileSystemWrapper::GetFileSize(fname, options.io_options,
&file_size, dbg);
if (!status.ok()) {
return status;
}
if (!file_size) {
*result = std::move(underlying);
return status;
}
// Create cipher stream
std::unique_ptr<BlockAccessCipherStream> stream;
size_t prefix_length;
status = CreateSequentialCipherStream(fname, underlying, options,
&prefix_length, &stream, dbg);
if (status.ok()) {
result->reset(new EncryptedSequentialFile(
std::move(underlying), std::move(stream), prefix_length));
}
return status;
}
// NewRandomAccessFile opens a file for random read access.
IOStatus NewRandomAccessFile(const std::string& fname,
const FileOptions& options,
std::unique_ptr<FSRandomAccessFile>* result,
IODebugContext* dbg) override {
result->reset();
if (options.use_mmap_reads) {
return IOStatus::InvalidArgument();
}
// Open file using underlying Env implementation
std::unique_ptr<FSRandomAccessFile> underlying;
auto status = FileSystemWrapper::NewRandomAccessFile(fname, options,
&underlying, dbg);
if (!status.ok()) {
return status;
}
std::unique_ptr<BlockAccessCipherStream> stream;
size_t prefix_length;
status = CreateRandomReadCipherStream(fname, underlying, options,
&prefix_length, &stream, dbg);
if (status.ok()) {
if (stream) {
result->reset(new EncryptedRandomAccessFile(
std::move(underlying), std::move(stream), prefix_length));
} else {
result->reset(underlying.release());
}
}
return status;
}
// NewWritableFile opens a file for sequential writing.
IOStatus NewWritableFile(const std::string& fname, const FileOptions& options,
std::unique_ptr<FSWritableFile>* result,
IODebugContext* dbg) override {
result->reset();
if (options.use_mmap_writes) {
return IOStatus::InvalidArgument();
}
// Open file using underlying Env implementation
std::unique_ptr<FSWritableFile> underlying;
IOStatus status =
FileSystemWrapper::NewWritableFile(fname, options, &underlying, dbg);
if (!status.ok()) {
return status;
}
return CreateWritableEncryptedFile(fname, underlying, options, result, dbg);
}
// Create an object that writes to a new file with the specified
// name. Deletes any existing file with the same name and creates a
// new file. On success, stores a pointer to the new file in
// *result and returns OK. On failure stores nullptr in *result and
// returns non-OK.
//
// The returned file will only be accessed by one thread at a time.
IOStatus ReopenWritableFile(const std::string& fname,
const FileOptions& options,
std::unique_ptr<FSWritableFile>* result,
IODebugContext* dbg) override {
result->reset();
if (options.use_mmap_writes) {
return IOStatus::InvalidArgument();
}
// Open file using underlying Env implementation
std::unique_ptr<FSWritableFile> underlying;
IOStatus status =
FileSystemWrapper::ReopenWritableFile(fname, options, &underlying, dbg);
if (!status.ok()) {
return status;
}
return CreateWritableEncryptedFile(fname, underlying, options, result, dbg);
}
// Reuse an existing file by renaming it and opening it as writable.
IOStatus ReuseWritableFile(const std::string& fname,
const std::string& old_fname,
const FileOptions& options,
std::unique_ptr<FSWritableFile>* result,
IODebugContext* dbg) override {
result->reset();
if (options.use_mmap_writes) {
return IOStatus::InvalidArgument();
}
// Open file using underlying Env implementation
std::unique_ptr<FSWritableFile> underlying;
auto status = FileSystemWrapper::ReuseWritableFile(
fname, old_fname, options, &underlying, dbg);
if (!status.ok()) {
return status;
}
return CreateWritableEncryptedFile(fname, underlying, options, result, dbg);
}
// Open `fname` for random read and write, if file doesn't exist the file
// will be created. On success, stores a pointer to the new file in
// *result and returns OK. On failure returns non-OK.
//
// The returned file will only be accessed by one thread at a time.
IOStatus NewRandomRWFile(const std::string& fname, const FileOptions& options,
std::unique_ptr<FSRandomRWFile>* result,
IODebugContext* dbg) override {
result->reset();
if (options.use_mmap_reads || options.use_mmap_writes) {
return IOStatus::InvalidArgument();
}
// Check file exists
bool isNewFile = !FileExists(fname, options.io_options, dbg).ok();
// Open file using underlying Env implementation
std::unique_ptr<FSRandomRWFile> underlying;
auto status =
FileSystemWrapper::NewRandomRWFile(fname, options, &underlying, dbg);
if (!status.ok()) {
return status;
}
// Create cipher stream
std::unique_ptr<BlockAccessCipherStream> stream;
size_t prefix_length = 0;
if (!isNewFile) {
// File already exists, read prefix
status = CreateRandomReadCipherStream(fname, underlying, options,
&prefix_length, &stream, dbg);
} else {
status = CreateRandomWriteCipherStream(fname, underlying, options,
&prefix_length, &stream, dbg);
}
if (status.ok()) {
if (stream) {
result->reset(new EncryptedRandomRWFile(
std::move(underlying), std::move(stream), prefix_length));
} else {
result->reset(underlying.release());
}
}
return status;
}
// Store in *result the attributes of the children of the specified
// directory.
// In case the implementation lists the directory prior to iterating the
// files
// and files are concurrently deleted, the deleted files will be omitted
// from
// result.
// The name attributes are relative to "dir".
// Original contents of *results are dropped.
// Returns OK if "dir" exists and "*result" contains its children.
// NotFound if "dir" does not exist, the calling process does not
// have
// permission to access "dir", or if "dir" is invalid.
// IOError if an IO Error was encountered
IOStatus GetChildrenFileAttributes(const std::string& dir,
const IOOptions& options,
std::vector<FileAttributes>* result,
IODebugContext* dbg) override {
auto status =
FileSystemWrapper::GetChildrenFileAttributes(dir, options, result, dbg);
if (!status.ok()) {
return status;
}
for (auto it = std::begin(*result); it != std::end(*result); ++it) {
// assert(it->size_bytes >= prefixLength);
// breaks env_basic_test when called on directory containing
// directories
// which makes subtraction of prefixLength worrisome since
// FileAttributes does not identify directories
EncryptionProvider* provider;
status = GetReadableProvider(it->name, &provider);
if (!status.ok()) {
return status;
} else if (provider != nullptr) {
it->size_bytes -= provider->GetPrefixLength();
}
}
return IOStatus::OK();
}
// Store the size of fname in *file_size.
IOStatus GetFileSize(const std::string& fname, const IOOptions& options,
uint64_t* file_size, IODebugContext* dbg) override {
auto status =
FileSystemWrapper::GetFileSize(fname, options, file_size, dbg);
if (!status.ok() || !(*file_size)) {
return status;
}
EncryptionProvider* provider;
status = GetReadableProvider(fname, &provider);
if (provider != nullptr && status.ok()) {
size_t prefixLength = provider->GetPrefixLength();
assert(*file_size >= prefixLength);
*file_size -= prefixLength;
}
return status;
}
private:
std::shared_ptr<EncryptionProvider> provider_;
};
} // namespace
std::shared_ptr<FileSystem> NewEncryptedFS(
const std::shared_ptr<FileSystem>& base,
const std::shared_ptr<EncryptionProvider>& provider) {
return std::make_shared<EncryptedFileSystemImpl>(base, provider);
}
// Returns an Env that encrypts data when stored on disk and decrypts data when
// read from disk.
Env* NewEncryptedEnv(Env* base_env,
const std::shared_ptr<EncryptionProvider>& provider) {
return new CompositeEnvWrapper(
base_env, NewEncryptedFS(base_env->GetFileSystem(), provider));
}
// Encrypt one or more (partial) blocks of data at the file offset.
// Length of data is given in dataSize.
Status BlockAccessCipherStream::Encrypt(uint64_t fileOffset, char *data, size_t dataSize) {
// Calculate block index
auto blockSize = BlockSize();
uint64_t blockIndex = fileOffset / blockSize;
size_t blockOffset = fileOffset % blockSize;
std::unique_ptr<char[]> blockBuffer;
std::string scratch;
AllocateScratch(scratch);
// Encrypt individual blocks.
while (1) {
char *block = data;
size_t n = std::min(dataSize, blockSize - blockOffset);
if (n != blockSize) {
// We're not encrypting a full block.
// Copy data to blockBuffer
if (!blockBuffer.get()) {
// Allocate buffer
blockBuffer = std::unique_ptr<char[]>(new char[blockSize]);
}
block = blockBuffer.get();
// Copy plain data to block buffer
memmove(block + blockOffset, data, n);
}
auto status = EncryptBlock(blockIndex, block, (char*)scratch.data());
if (!status.ok()) {
return status;
}
if (block != data) {
// Copy encrypted data back to `data`.
memmove(data, block + blockOffset, n);
}
dataSize -= n;
if (dataSize == 0) {
return Status::OK();
}
data += n;
blockOffset = 0;
blockIndex++;
}
}
// Decrypt one or more (partial) blocks of data at the file offset.
// Length of data is given in dataSize.
Status BlockAccessCipherStream::Decrypt(uint64_t fileOffset, char *data, size_t dataSize) {
// Calculate block index
auto blockSize = BlockSize();
uint64_t blockIndex = fileOffset / blockSize;
size_t blockOffset = fileOffset % blockSize;
std::unique_ptr<char[]> blockBuffer;
std::string scratch;
AllocateScratch(scratch);
// Decrypt individual blocks.
while (1) {
char *block = data;
size_t n = std::min(dataSize, blockSize - blockOffset);
if (n != blockSize) {
// We're not decrypting a full block.
// Copy data to blockBuffer
if (!blockBuffer.get()) {
// Allocate buffer
blockBuffer = std::unique_ptr<char[]>(new char[blockSize]);
}
block = blockBuffer.get();
// Copy encrypted data to block buffer
memmove(block + blockOffset, data, n);
}
auto status = DecryptBlock(blockIndex, block, (char*)scratch.data());
if (!status.ok()) {
return status;
}
if (block != data) {
// Copy decrypted data back to `data`.
memmove(data, block + blockOffset, n);
}
// Simply decrementing dataSize by n could cause it to underflow,
// which will very likely make it read over the original bounds later
assert(dataSize >= n);
if (dataSize < n) {
return Status::Corruption("Cannot decrypt data at given offset");
}
dataSize -= n;
if (dataSize == 0) {
return Status::OK();
}
data += n;
blockOffset = 0;
blockIndex++;
}
}
const char* ROT13BlockCipher::Name() const { return kROT13CipherName; }
// Encrypt a block of data.
// Length of data is equal to BlockSize().
Status ROT13BlockCipher::Encrypt(char* data) {
for (size_t i = 0; i < blockSize_; ++i) {
data[i] += 13;
}
return Status::OK();
}
// Decrypt a block of data.
// Length of data is equal to BlockSize().
Status ROT13BlockCipher::Decrypt(char* data) { return Encrypt(data); }
// Allocate scratch space which is passed to EncryptBlock/DecryptBlock.
void CTRCipherStream::AllocateScratch(std::string& scratch) {
auto blockSize = cipher_->BlockSize();
scratch.reserve(blockSize);
}
// Encrypt a block of data at the given block index.
// Length of data is equal to BlockSize();
Status CTRCipherStream::EncryptBlock(uint64_t blockIndex, char* data,
char* scratch) {
// Create nonce + counter
auto blockSize = cipher_->BlockSize();
memmove(scratch, iv_.data(), blockSize);
EncodeFixed64(scratch, blockIndex + initialCounter_);
// Encrypt nonce+counter
auto status = cipher_->Encrypt(scratch);
if (!status.ok()) {
return status;
}
// XOR data with ciphertext.
for (size_t i = 0; i < blockSize; i++) {
data[i] = data[i] ^ scratch[i];
}
return Status::OK();
}
// Decrypt a block of data at the given block index.
// Length of data is equal to BlockSize();
Status CTRCipherStream::DecryptBlock(uint64_t blockIndex, char* data,
char* scratch) {
// For CTR decryption & encryption are the same
return EncryptBlock(blockIndex, data, scratch);
}
const char* CTREncryptionProvider::Name() const { return kCTRProviderName; }
// GetPrefixLength returns the length of the prefix that is added to every file
// and used for storing encryption options.
// For optimal performance, the prefix length should be a multiple of
// the page size.
size_t CTREncryptionProvider::GetPrefixLength() const {
return defaultPrefixLength;
}
Status CTREncryptionProvider::TEST_Initialize() {
if (!cipher_) {
return BlockCipher::CreateFromString(
ConfigOptions(), std::string(kROT13CipherName) + ":32", &cipher_);
}
return Status::OK();
}
Status CTREncryptionProvider::AddCipher(const std::string& /*descriptor*/,
const char* cipher, size_t len,
bool /*for_write*/) {
if (cipher_) {
return Status::NotSupported("Cannot add keys to CTREncryptionProvider");
} else if (strcmp(kROT13CipherName, cipher) == 0) {
cipher_.reset(new ROT13BlockCipher(len));
return Status::OK();
} else {
return BlockCipher::CreateFromString(ConfigOptions(), std::string(cipher),
&cipher_);
}
}
// decodeCTRParameters decodes the initial counter & IV from the given
// (plain text) prefix.
static void decodeCTRParameters(const char* prefix, size_t blockSize,
uint64_t& initialCounter, Slice& iv) {
// First block contains 64-bit initial counter
initialCounter = DecodeFixed64(prefix);
// Second block contains IV
iv = Slice(prefix + blockSize, blockSize);
}
// CreateNewPrefix initialized an allocated block of prefix memory
// for a new file.
Status CTREncryptionProvider::CreateNewPrefix(const std::string& /*fname*/,
char* prefix,
size_t prefixLength) const {
if (!cipher_) {
return Status::InvalidArgument("Encryption Cipher is missing");
}
// Create & seed rnd.
Random rnd((uint32_t)SystemClock::Default()->NowMicros());
// Fill entire prefix block with random values.
for (size_t i = 0; i < prefixLength; i++) {
prefix[i] = rnd.Uniform(256) & 0xFF;
}
// Take random data to extract initial counter & IV
auto blockSize = cipher_->BlockSize();
uint64_t initialCounter;
Slice prefixIV;
decodeCTRParameters(prefix, blockSize, initialCounter, prefixIV);
// Now populate the rest of the prefix, starting from the third block.
PopulateSecretPrefixPart(prefix + (2 * blockSize),
prefixLength - (2 * blockSize), blockSize);
// Encrypt the prefix, starting from block 2 (leave block 0, 1 with initial
// counter & IV unencrypted)
CTRCipherStream cipherStream(cipher_, prefixIV.data(), initialCounter);
Status status;
{
PERF_TIMER_GUARD(encrypt_data_nanos);
status = cipherStream.Encrypt(0, prefix + (2 * blockSize),
prefixLength - (2 * blockSize));
}
if (!status.ok()) {
return status;
}
return Status::OK();
}
// PopulateSecretPrefixPart initializes the data into a new prefix block
// in plain text.
// Returns the amount of space (starting from the start of the prefix)
// that has been initialized.
size_t CTREncryptionProvider::PopulateSecretPrefixPart(
char* /*prefix*/, size_t /*prefixLength*/, size_t /*blockSize*/) const {
// Nothing to do here, put in custom data in override when needed.
return 0;
}
Status CTREncryptionProvider::CreateCipherStream(
const std::string& fname, const EnvOptions& options, Slice& prefix,
std::unique_ptr<BlockAccessCipherStream>* result) {
if (!cipher_) {
return Status::InvalidArgument("Encryption Cipher is missing");
}
// Read plain text part of prefix.
auto blockSize = cipher_->BlockSize();
uint64_t initialCounter;
Slice iv;
decodeCTRParameters(prefix.data(), blockSize, initialCounter, iv);
// If the prefix is smaller than twice the block size, we would below read a
// very large chunk of the file (and very likely read over the bounds)
assert(prefix.size() >= 2 * blockSize);
if (prefix.size() < 2 * blockSize) {
return Status::Corruption("Unable to read from file " + fname +
": read attempt would read beyond file bounds");
}
// Decrypt the encrypted part of the prefix, starting from block 2 (block 0, 1
// with initial counter & IV are unencrypted)
CTRCipherStream cipherStream(cipher_, iv.data(), initialCounter);
Status status;
{
PERF_TIMER_GUARD(decrypt_data_nanos);
status = cipherStream.Decrypt(0, (char*)prefix.data() + (2 * blockSize),
prefix.size() - (2 * blockSize));
}
if (!status.ok()) {
return status;
}
// Create cipher stream
return CreateCipherStreamFromPrefix(fname, options, initialCounter, iv,
prefix, result);
}
// CreateCipherStreamFromPrefix creates a block access cipher stream for a file
// given given name and options. The given prefix is already decrypted.
Status CTREncryptionProvider::CreateCipherStreamFromPrefix(
const std::string& /*fname*/, const EnvOptions& /*options*/,
uint64_t initialCounter, const Slice& iv, const Slice& /*prefix*/,
std::unique_ptr<BlockAccessCipherStream>* result) {
(*result) = std::unique_ptr<BlockAccessCipherStream>(
new CTRCipherStream(cipher_, iv.data(), initialCounter));
return Status::OK();
}
#endif // ROCKSDB_LITE
} // namespace ROCKSDB_NAMESPACE