SFTP Protocol v6 Quick reference tables

§4.3: Packet types

name	value	hex
SSH_FXP_INIT	1	0x01
SSH_FXP_VERSION	2	0x02
SSH_FXP_OPEN	3	0x03
SSH_FXP_CLOSE	4	0x04
SSH_FXP_READ	5	0x05
SSH_FXP_WRITE	6	0x06
SSH_FXP_LSTAT	7	0x07
SSH_FXP_FSTAT	8	0x08
SSH_FXP_SETSTAT	9	0x09
SSH_FXP_FSETSTAT	10	0x0A
SSH_FXP_OPENDIR	11	0x0B
SSH_FXP_READDIR	12	0x0C
SSH_FXP_REMOVE	13	0x0D
SSH_FXP_MKDIR	14	0x0E
SSH_FXP_RMDIR	15	0x0F
SSH_FXP_REALPATH	16	0x10
SSH_FXP_STAT	17	0x11
SSH_FXP_RENAME	18	0x12
SSH_FXP_READLINK	19	0x13
---	20	0x14
SSH_FXP_LINK	21	0x15
SSH_FXP_BLOCK	22	0x16
SSH_FXP_UNBLOCK	23	0x17
SSH_FXP_STATUS	101	0x65
SSH_FXP_HANDLE	102	0x66
SSH_FXP_DATA	103	0x67
SSH_FXP_NAME	104	0x68
SSH_FXP_ATTRS	105	0x69
SSH_FXP_EXTENDED	200	0xC8
SSH_FXP_EXTENDED_REPLY	201	0xC9

§7: File attributes

SSH_FILEXFER...	hex
~_ATTR_SIZE	0x0001
--- (deprecated)	0x0002
~_ATTR_PERMISSIONS	0x0004
~_ATTR_ACCESSTIME	0x0008
~_ATTR_CREATETIME	0x0010
~_ATTR_MODIFYTIME	0x0020
~_ATTR_ACL	0x0040
~_ATTR_OWNERGROUP	0x0080
~_ATTR_SUBSECOND_TIMES	0x0100
~_ATTR_BITS	0x0200
~_ATTR_ALLOCATION_SIZE	0x0400
~_ATTR_TEXT_HINT	0x0800
~_ATTR_MIME_TYPE	0x1000
~_ATTR_LINK_COUNT	0x2000
~_ATTR_UNTRANSLATED_NAME	0x4000
~_ATTR_CTIME	0x8000
~_ATTR_EXTENDED	0x80000000

Support table

type	attr	supported by	mask
uint32	valid-attribute-flags	(always present)
byte	type	(always present)
uint64	size	SIZE	0x0001
uint64	allocation-size	ALLOCATION	0x0400
string	owner	OWNERGROUP	0x0080
string	group	OWNERGROUP	0x0080
uint32	permissions	PERMISSIONS	0x0004
int64	atime	MODIFIED	0x0008
uint32	atime-nseconds	SUBSECOND_TIMES	0x0108
int64	createtime	CREATETIME	0x0010
uint32	createtime-nseconds	SUBSECOND_TIMES	0x0110
int64	mtime	ACMODTIME	0x0020
uint32	mtime-nseconds	SUBSECOND_TIMES	0x0120
int64	ctime	CTIME	0x8000
uint32	ctime-nseconds	SUBSECOND_TIMES	0x8010
string	acl	ACL	0x0040
uint32	attrib-bits	BITS	0x0200
uint32	attrib-bits-valid	BITS	0x0200
byte	text-hint	TEXT_HINT	0x0800
string	mime-type	MIME_TYPE	0x1000
uint32	link-count	LINK_COUNT	0x2000
string	untranslated-name	UNTRANSLATED_NAME	0x4000
uint32	extended-count	EXTENDED	0x80000000

supported by field means that the field only presents if valid-attribute-flags has the bit set indicated by SSH_FILEXFER_..., as shown in the mask column for reference. Otherwise, the field is skipped.

Note on owner/group information: In SFTP v3, owners and groups were reported by uid/gid. v6 no longer supports the flag SSH_FILEXFER_UIDGID, and can only report owner or group by names. Refer to the spec of v6:

0x00000002 was used in a previous version of this protocol. It is now a reserved value and MUST NOT appear in the mask. Some future version of this protocol may reuse this value.

… where 0x00000002 is actually the SSH_FILEXFER_UIDGID in SFTP v3.

To be compatible with most interfaces (POSIX?), v6 clients must come up a way mapping those strings back to ids.

Nanosecond fields: Special cases are *-nseconds where one also requires the presence of flag supporting its timestamp (in seconds). The specification did not make it clear enough, and some client might exhabit nonsensical behavior.

As a side note, the flags Green End SFTP Server supply to its client for SFTP v6 is 0xA3AD.

§7.2 File types

SSH_FILEXFER_TYPE...	value	st_mode	hex	meaning
~_REGULAR	1	S_IFREG	0x8000	regular file
~_DIRECTORY	2	S_IFDIR	0x4000	directory
~_SYMLINK	3	S_IFLNK	0xA000	symbolic link
~_SPECIAL	4	(N/A)
~_UNKNOWN	5	(N/A)
~_SOCKET	6	S_IFSOCK	0xC000	socket
~_CHAR_DEVICE	7	S_IFCHR	0x2000	character device
~_BLOCK_DEVICE	8	S_IFBLK	0x6000	block device
~_FIFO	9	S_IFIFO	0x1000	FIFO

The enums of st_mode are referred from the manpage. As a small hack, GE stores the entire st_mode of an inode in the permissions field, so you don't have to map it if you know the server is a GE one.

§7.9 File attrib-bits

(WIP)

SSH_FILEXFER_ATTR_FLAGS...	value
~_READONLY	0x0001
~_SYSTEM	0x0002
~_HIDDEN	0x0004
~_CASE_INSENSITIVE	0x0008
~_ARCHIVE	0x0010
~_ENCRYPTED	0x0020
~_COMPRESSED	0x0040
~_SPARSE	0x0080
~_APPEND_ONLY	0x0100
~_IMMUTABLE	0x0200
~_SYNC	0x0400
~_TRANSLATION_ERR	0x0800

§8.3 Rename flag

(WIP)

​​​​   SSH_FXF_RENAME_OVERWRITE  0x00000001
​​​​   SSH_FXF_RENAME_ATOMIC     0x00000002
​​​​   SSH_FXF_RENAME_NATIVE     0x00000004

§9.1 Response status code

(WIP)

​​​​   SSH_FX_OK                            0
​​​​   SSH_FX_EOF                           1
​​​​   SSH_FX_NO_SUCH_FILE                  2
​​​​   SSH_FX_PERMISSION_DENIED             3
​​​​   SSH_FX_FAILURE                       4
​​​​   SSH_FX_BAD_MESSAGE                   5
​​​​   SSH_FX_NO_CONNECTION                 6
​​​​   SSH_FX_CONNECTION_LOST               7
​​​​   SSH_FX_OP_UNSUPPORTED                8
​​​​   SSH_FX_INVALID_HANDLE                9
​​​​   SSH_FX_NO_SUCH_PATH                  10
​​​​   SSH_FX_FILE_ALREADY_EXISTS           11
​​​​   SSH_FX_WRITE_PROTECT                 12
​​​​   SSH_FX_NO_MEDIA                      13
​​​​   SSH_FX_NO_SPACE_ON_FILESYSTEM        14
​​​​   SSH_FX_QUOTA_EXCEEDED                15
​​​​   SSH_FX_UNKNOWN_PRINCIPAL             16
​​​​   SSH_FX_LOCK_CONFLICT                 17
​​​​   SSH_FX_DIR_NOT_EMPTY                 18
​​​​   SSH_FX_NOT_A_DIRECTORY               19
​​​​   SSH_FX_INVALID_FILENAME              20
​​​​   SSH_FX_LINK_LOOP                     21
​​​​   SSH_FX_CANNOT_DELETE                 22
​​​​   SSH_FX_INVALID_PARAMETER             23
​​​​   SSH_FX_FILE_IS_A_DIRECTORY           24
​​​​   SSH_FX_BYTE_RANGE_LOCK_CONFLICT      25
​​​​   SSH_FX_BYTE_RANGE_LOCK_REFUSED       26
​​​​   SSH_FX_DELETE_PENDING                27
​​​​   SSH_FX_FILE_CORRUPT                  28
​​​​   SSH_FX_OWNER_INVALID                 29
​​​​   SSH_FX_GROUP_INVALID                 30
​​​​   SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK       31