#include <grpc/support/port_platform.h>
#include "src/core/tsi/alts/frame_protector/alts_frame_protector.h"
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include "src/core/lib/gpr/useful.h"
#include "src/core/tsi/alts/crypt/gsec.h"
#include "src/core/tsi/alts/frame_protector/alts_crypter.h"
#include "src/core/tsi/alts/frame_protector/frame_handler.h"
#include "src/core/tsi/transport_security.h"

Include dependency graph for alts_frame_protector.cc:

Classes
struct	alts_frame_protector

Functions
tsi_result	alts_create_frame_protector (const uint8_t key, size_t key_size, bool is_client, bool is_rekey, size_t max_protected_frame_size, tsi_frame_protector **self)

static void	alts_destroy (tsi_frame_protector *self)

static tsi_result	alts_protect (tsi_frame_protector self, const unsigned char unprotected_bytes, size_t unprotected_bytes_size, unsigned char protected_output_frames, size_t *protected_output_frames_size)

static tsi_result	alts_protect_flush (tsi_frame_protector self, unsigned char protected_output_frames, size_t protected_output_frames_size, size_t still_pending_size)

static tsi_result	alts_unprotect (tsi_frame_protector self, const unsigned char protected_frames_bytes, size_t protected_frames_bytes_size, unsigned char unprotected_bytes, size_t *unprotected_bytes_size)

static grpc_status_code	create_alts_crypters (const uint8_t key, size_t key_size, bool is_client, bool is_rekey, alts_frame_protector impl, char **error_details)

static void	ensure_buffer_size (alts_frame_protector *impl)

static size_t	max_encrypted_payload_bytes (alts_frame_protector *impl)

static tsi_result	seal (alts_frame_protector *impl)

static tsi_result	unseal (alts_frame_protector *impl)

Variables
static const tsi_frame_protector_vtable	alts_frame_protector_vtable

constexpr size_t	kAltsRecordProtocolFrameLimit = 5

constexpr size_t	kAltsRecordProtocolRekeyFrameLimit = 8

constexpr size_t	kDefaultFrameLength = 16 * 1024

constexpr size_t	kMaxFrameLength = 1024 * 1024

constexpr size_t	kMinFrameLength = 1024

Function Documentation

◆ alts_create_frame_protector()

tsi_result alts_create_frame_protector	(	const uint8_t *	key,
		size_t	key_size,
		bool	is_client,
		bool	is_rekey,
		size_t *	max_protected_frame_size,
		tsi_frame_protector **	self
	)

TODO: Add a parameter to the interface to support the use of different record protocols within a frame protector.

This method creates a frame protector.

key: a symmetric key used to seal/unseal frames.
key_size: the size of symmetric key.
is_client: a flag indicating if the frame protector will be used at client (is_client = true) or server (is_client = false) side.
is_rekey: a flag indicating if the frame protector will use an AEAD with rekeying.
max_protected_frame_size: an in/out parameter indicating max frame size to be used by the frame protector. If it is nullptr, the default frame size will be used. Otherwise, the provided frame size will be adjusted (if not falling into a valid frame range) and used.
self: a pointer to the frame protector returned from the method.

This method returns TSI_OK on success and TSI_INTERNAL_ERROR otherwise.

Set maximum frame size to be used by a frame protector. If it is nullptr, a default frame size will be used. Otherwise, the provided frame size will be adjusted (if not falling into a valid frame range) and used.

Definition at line 363 of file alts_frame_protector.cc.

◆ alts_destroy()

static void alts_destroy ( tsi_frame_protector * self )

static

Definition at line 314 of file alts_frame_protector.cc.

◆ alts_protect()

static tsi_result alts_protect	(	tsi_frame_protector *	self,
		const unsigned char *	unprotected_bytes,
		size_t *	unprotected_bytes_size,
		unsigned char *	protected_output_frames,
		size_t *	protected_output_frames_size
	)

static

If more payload can be buffered, we buffer it as much as possible to in_place_protect_buffer.

If a full frame has been buffered, we output it. If the first condition holds, then there exists an unencrypted full frame. If the second condition holds, then there exists a full frame that has already been encrypted.

Definition at line 142 of file alts_frame_protector.cc.

◆ alts_protect_flush()

static tsi_result alts_protect_flush	(	tsi_frame_protector *	self,
		unsigned char *	protected_output_frames,
		size_t *	protected_output_frames_size,
		size_t *	still_pending_size
	)

static

If there's nothing to flush (i.e., in_place_protect_buffer is empty), we're done.

If a new frame can start being processed, we encrypt the payload and reset the frame writer to point to in_place_protect_buffer that holds the newly sealed frame.

Write the sealed frame as much as possible to protected_output_frames. It's possible a frame will not be written out completely by a single flush (i.e., still_pending_size != 0), in which case the flush should be called iteratively until a complete frame has been written out.

If the current frame has been finished processing (i.e., sealed and written out completely), we empty in_place_protect_buffer.

Definition at line 82 of file alts_frame_protector.cc.

◆ alts_unprotect()

static tsi_result alts_unprotect	(	tsi_frame_protector *	self,
		const unsigned char *	protected_frames_bytes,
		size_t *	protected_frames_bytes_size,
		unsigned char *	unprotected_bytes,
		size_t *	unprotected_bytes_size
	)

static

If a new frame can start being processed, we reset the frame reader to point to in_place_unprotect_buffer that will be used to hold deframed result.

If a full frame has not yet been read, we read more bytes from protected_frames_bytes until a full frame has been read. We also need to make sure in_place_unprotect_buffer is large enough to hold a complete frame.

If a full frame has been read, we unseal it, and write out the deframed result to unprotected_bytes.

Definition at line 234 of file alts_frame_protector.cc.

◆ create_alts_crypters()

static grpc_status_code create_alts_crypters	(	const uint8_t *	key,
		size_t	key_size,
		bool	is_client,
		bool	is_rekey,
		alts_frame_protector *	impl,
		char **	error_details
	)

static

Definition at line 330 of file alts_frame_protector.cc.

◆ ensure_buffer_size()

static void ensure_buffer_size ( alts_frame_protector * impl )

static

constexpr

Definition at line 37 of file alts_frame_protector.cc.

Classes

Functions

Variables

Function Documentation

◆ alts_create_frame_protector()

◆ alts_destroy()

◆ alts_protect()

◆ alts_protect_flush()

◆ alts_unprotect()

◆ create_alts_crypters()

◆ ensure_buffer_size()

◆ max_encrypted_payload_bytes()

◆ seal()

◆ unseal()

Variable Documentation

◆ alts_frame_protector_vtable

◆ kAltsRecordProtocolFrameLimit

◆ kAltsRecordProtocolRekeyFrameLimit

◆ kDefaultFrameLength

◆ kMaxFrameLength

◆ kMinFrameLength