Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1351 insertions, 0 deletions

diff --git a/src/rocksdb/env/env_encryption.cc b/src/rocksdb/env/env_encryption.cc
new file mode 100644
index 000000000..c6b0a257d
--- /dev/null
+++ b/src/rocksdb/env/env_encryption.cc
@@ -0,0 +1,1351 @@
+//  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 "rocksdb/utilities/customizable_util.h"
+#include "rocksdb/utilities/options_type.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
+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();
+}
+
+// true if Sync() and Fsync() are safe to call concurrently with Append()
+// and Flush().
+bool EncryptedWritableFile::IsSyncThreadSafe() const {
+  return file_->IsSyncThreadSafe();
+}
+
+// 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 {
+static std::unordered_map<std::string, OptionTypeInfo> encrypted_fs_type_info =
+    {
+        {"provider",
+         OptionTypeInfo::AsCustomSharedPtr<EncryptionProvider>(
+             0 /* No offset, whole struct*/, OptionVerificationType::kByName,
+             OptionTypeFlags::kNone)},
+};
+// EncryptedFileSystemImpl implements an FileSystemWrapper that adds encryption
+// to files stored on disk.
+class EncryptedFileSystemImpl : public EncryptedFileSystem {
+ public:
+  const char* Name() const override {
+    return EncryptedFileSystem::kClassName();
+  }
+  // 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;
+    RegisterOptions("EncryptionProvider", &provider_, &encrypted_fs_type_info);
+  }
+
+  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
+
+Status NewEncryptedFileSystemImpl(
+    const std::shared_ptr<FileSystem>& base,
+    const std::shared_ptr<EncryptionProvider>& provider,
+    std::unique_ptr<FileSystem>* result) {
+  result->reset(new EncryptedFileSystemImpl(base, provider));
+  return Status::OK();
+}
+
+std::shared_ptr<FileSystem> NewEncryptedFS(
+    const std::shared_ptr<FileSystem>& base,
+    const std::shared_ptr<EncryptionProvider>& provider) {
+  std::unique_ptr<FileSystem> efs;
+  Status s = NewEncryptedFileSystemImpl(base, provider, &efs);
+  if (s.ok()) {
+    s = efs->PrepareOptions(ConfigOptions());
+  }
+  if (s.ok()) {
+    std::shared_ptr<FileSystem> result(efs.release());
+    return result;
+  } else {
+    return nullptr;
+  }
+}
+// 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++;
+  }
+}
+
+namespace {
+static std::unordered_map<std::string, OptionTypeInfo>
+    rot13_block_cipher_type_info = {
+        {"block_size",
+         {0 /* No offset, whole struct*/, OptionType::kInt,
+          OptionVerificationType::kNormal, OptionTypeFlags::kNone}},
+};
+// Implements a BlockCipher using ROT13.
+//
+// Note: This is a sample implementation of BlockCipher,
+// it is NOT considered safe and should NOT be used in production.
+class ROT13BlockCipher : public BlockCipher {
+ private:
+  size_t blockSize_;
+
+ public:
+  explicit ROT13BlockCipher(size_t blockSize) : blockSize_(blockSize) {
+    RegisterOptions("ROT13BlockCipherOptions", &blockSize_,
+                    &rot13_block_cipher_type_info);
+  }
+
+  static const char* kClassName() { return "ROT13"; }
+  const char* Name() const override { return kClassName(); }
+  // BlockSize returns the size of each block supported by this cipher stream.
+  size_t BlockSize() override { return blockSize_; }
+
+  // Encrypt a block of data.
+  // Length of data is equal to BlockSize().
+  Status Encrypt(char* data) override {
+    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 Decrypt(char* data) override { return Encrypt(data); }
+};
+static const std::unordered_map<std::string, OptionTypeInfo>
+    ctr_encryption_provider_type_info = {
+        {"cipher",
+         OptionTypeInfo::AsCustomSharedPtr<BlockCipher>(
+             0 /* No offset, whole struct*/, OptionVerificationType::kByName,
+             OptionTypeFlags::kNone)},
+};
+}  // anonymous namespace
+
+// 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);
+}
+
+CTREncryptionProvider::CTREncryptionProvider(
+    const std::shared_ptr<BlockCipher>& c)
+    : cipher_(c) {
+  RegisterOptions("Cipher", &cipher_, &ctr_encryption_provider_type_info);
+}
+
+bool CTREncryptionProvider::IsInstanceOf(const std::string& name) const {
+  // Special case for test purposes.
+  if (name == "1://test" && cipher_ != nullptr) {
+    return cipher_->IsInstanceOf(ROT13BlockCipher::kClassName());
+  } else {
+    return EncryptionProvider::IsInstanceOf(name);
+  }
+}
+
+// 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::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(ROT13BlockCipher::kClassName(), 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();
+}
+
+namespace {
+static void RegisterEncryptionBuiltins() {
+  static std::once_flag once;
+  std::call_once(once, [&]() {
+    auto lib = ObjectRegistry::Default()->AddLibrary("encryption");
+    // Match "CTR" or "CTR://test"
+    lib->AddFactory<EncryptionProvider>(
+        ObjectLibrary::PatternEntry(CTREncryptionProvider::kClassName(), true)
+            .AddSuffix("://test"),
+        [](const std::string& uri, std::unique_ptr<EncryptionProvider>* guard,
+           std::string* /*errmsg*/) {
+          if (EndsWith(uri, "://test")) {
+            std::shared_ptr<BlockCipher> cipher =
+                std::make_shared<ROT13BlockCipher>(32);
+            guard->reset(new CTREncryptionProvider(cipher));
+          } else {
+            guard->reset(new CTREncryptionProvider());
+          }
+          return guard->get();
+        });
+
+    lib->AddFactory<EncryptionProvider>(
+        "1://test", [](const std::string& /*uri*/,
+                       std::unique_ptr<EncryptionProvider>* guard,
+                       std::string* /*errmsg*/) {
+          std::shared_ptr<BlockCipher> cipher =
+              std::make_shared<ROT13BlockCipher>(32);
+          guard->reset(new CTREncryptionProvider(cipher));
+          return guard->get();
+        });
+
+    // Match "ROT13" or "ROT13:[0-9]+"
+    lib->AddFactory<BlockCipher>(
+        ObjectLibrary::PatternEntry(ROT13BlockCipher::kClassName(), true)
+            .AddNumber(":"),
+        [](const std::string& uri, std::unique_ptr<BlockCipher>* guard,
+           std::string* /* errmsg */) {
+          size_t colon = uri.find(':');
+          if (colon != std::string::npos) {
+            size_t block_size = ParseSizeT(uri.substr(colon + 1));
+            guard->reset(new ROT13BlockCipher(block_size));
+          } else {
+            guard->reset(new ROT13BlockCipher(32));
+          }
+
+          return guard->get();
+        });
+  });
+}
+}  // namespace
+
+Status BlockCipher::CreateFromString(const ConfigOptions& config_options,
+                                     const std::string& value,
+                                     std::shared_ptr<BlockCipher>* result) {
+  RegisterEncryptionBuiltins();
+  return LoadSharedObject<BlockCipher>(config_options, value, nullptr, result);
+}
+
+Status EncryptionProvider::CreateFromString(
+    const ConfigOptions& config_options, const std::string& value,
+    std::shared_ptr<EncryptionProvider>* result) {
+  RegisterEncryptionBuiltins();
+  return LoadSharedObject<EncryptionProvider>(config_options, value, nullptr,
+                                              result);
+}
+
+#endif  // ROCKSDB_LITE
+
+}  // namespace ROCKSDB_NAMESPACE