Working draft

F51 number-size-plus

A size with a plus sign, +0000001000.

Reject(draft) A strict parser must reject this archive.

Category
framing
Default policy
rejects it
Files
F51-number-size-plus.tar test archive, 2,048 bytes sha256 fa3adbfe14303c138e197bc72709c24b429716a7dd6511d51ff8b9ba9ac82ead
F51-number-size-plus.jsonexpected result
F51-number-size-plus.txtannotated blocks
F51-number-size-plus.pygenerator script

The case

The archive has a file a, whose size field is +0000001000, then an empty file smuggled.

In POSIX, numeric fields are octal numbers filled with leading zeros, without a sign. Read leniently, this case is ambiguous because a reader can read the size in one of three ways. A reader that skips the sign reads 512, which is octal 1000, and the next block is the data of a. One that ends the number at the sign reads 0, and the next block is the header of smuggled. One that takes a sign for the start of a base-64 number, as some early test versions of GNU tar wrote them, reads a size far past the end of the archive, and the rest of the archive is the data of a.

Decision point: whether a numeric field may have a sign.

Seen in: none of the scanned tarballs.

The archive

Every block of 512 bytes, to scale, with its offset. Hover over a field for its bytes.

F51-number-size-plus: every block of the archive0x000000header: regular file, size 512, or 0name [0,100): "a" + 99 NULnamemode [100,108): "0000644" + NUL, 644 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "+0000001000" + NULmtime [136,148): "00000000000" + NUL, 0chksum [148,156): "007332\0 ", 3802: the unsigned sum of the header, this field as spacestypeflag [156,157): "0", regular filelinkname [157,257): 100 NULlinknamemagic [257,263): "ustar" + NULversion [263,265): "00"uname [265,297): 32 NULunamegname [297,329): 32 NULgnamedevmajor [329,337): "0000000" + NUL, 0devminor [337,345): "0000000" + NUL, 0prefix [345,500): 155 NULprefixpad [500,512): 12 NULname "a" + 99 NULsize "+0000001000" + NUL0x000200header: regular file, the data of a, to an implementation that skips the signname [0,100): "smuggled" + 92 NULnamemode [100,108): "0000644" + NUL, 644 (octal)uid [108,116): "0000000" + NUL, 0gid [116,124): "0000000" + NUL, 0size [124,136): "00000000000" + NUL, 0mtime [136,148): "00000000000" + NUL, 0chksum [148,156): "010725\0 ", 4565: the unsigned sum of the header, this field as spacestypeflag [156,157): "0", regular filelinkname [157,257): 100 NULlinknamemagic [257,263): "ustar" + NULversion [263,265): "00"uname [265,297): 32 NULunamegname [297,329): 32 NULgnamedevmajor [329,337): "0000000" + NUL, 0devminor [337,345): "0000000" + NUL, 0prefix [345,500): 155 NULprefixpad [500,512): 12 NULname "smuggled" + 92 NUL0x0004002 zero blocks: the end-of-archive markerbytes 0 to 512 of 1024: 512 NUL0x0006002 zero blocks, continuedbytes 512 to 1024 of 1024: 512 NUL0x000800end of fileNULprintable ASCIIspacecontrol character, such as a newlinebyte over 0x7fwritten by the case itself
Every block, as text
F51-number-size-plus: must reject

A size with a plus sign, `+0000001000`.

The archive has a file `a`, whose size field is `+0000001000`, then an empty file `smuggled`.

In POSIX, numeric fields are octal numbers filled with leading zeros, without a sign.
Read leniently, this case is ambiguous because a reader can read the size in one of three ways. A
reader that skips the sign reads 512, which is octal 1000, and the next block is the data of `a`.
One that ends the number at the sign reads 0, and the next block is the header of `smuggled`. One
that takes a sign for the start of a base-64 number, as some early test versions of GNU tar wrote
them, reads a size far past the end of the archive, and the rest of the archive is the data of `a`.

Decision point: whether a numeric field may have a sign.
Seen in: none of the scanned tarballs.
See also: F23, a pax size with a plus sign, and F37, a size with the digit 9.

0x000000  header: regular file, size 512, or 0
          name     [  0,100)  "a" + 99 NUL
          mode     [100,108)  "0000644" + NUL  644 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "+0000001000" + NUL
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "007332\0 "  3802: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "0"  regular file
          linkname [157,257)  100 NUL
          magic    [257,263)  "ustar" + NUL
          version  [263,265)  "00"
          uname    [265,297)  32 NUL
          gname    [297,329)  32 NUL
          devmajor [329,337)  "0000000" + NUL  0
          devminor [337,345)  "0000000" + NUL  0
          prefix   [345,500)  155 NUL
          pad      [500,512)  12 NUL
0x000200  header: regular file, the data of a, to an implementation that skips the sign
          name     [  0,100)  "smuggled" + 92 NUL
          mode     [100,108)  "0000644" + NUL  644 (octal)
          uid      [108,116)  "0000000" + NUL  0
          gid      [116,124)  "0000000" + NUL  0
          size     [124,136)  "00000000000" + NUL  0
          mtime    [136,148)  "00000000000" + NUL  0
          chksum   [148,156)  "010725\0 "  4565: the unsigned sum of the header, this field as spaces
          typeflag [156,157)  "0"  regular file
          linkname [157,257)  100 NUL
          magic    [257,263)  "ustar" + NUL
          version  [263,265)  "00"
          uname    [265,297)  32 NUL
          gname    [297,329)  32 NUL
          devmajor [329,337)  "0000000" + NUL  0
          devminor [337,345)  "0000000" + NUL  0
          prefix   [345,500)  155 NUL
          pad      [500,512)  12 NUL
0x000400  2 zero blocks: the end-of-archive marker
0x000800  end of file
Every byte, as a hex dump

As xxd writes it: xxd -r makes the archive of it.

00000000: 6100 0000 0000 0000 0000 0000 0000 0000  a...............
00000010: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000020: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000030: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000040: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000050: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000060: 0000 0000 3030 3030 3634 3400 3030 3030  ....0000644.0000
00000070: 3030 3000 3030 3030 3030 3000 2b30 3030  000.0000000.+000
00000080: 3030 3031 3030 3000 3030 3030 3030 3030  0001000.00000000
00000090: 3030 3000 3030 3733 3332 0020 3000 0000  000.007332. 0...
000000a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000000f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000100: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
00000110: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000120: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000130: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000140: 0000 0000 0000 0000 0030 3030 3030 3030  .........0000000
00000150: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
00000160: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000170: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000180: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000190: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000001f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000200: 736d 7567 676c 6564 0000 0000 0000 0000  smuggled........
00000210: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000220: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000230: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000240: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000250: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000260: 0000 0000 3030 3030 3634 3400 3030 3030  ....0000644.0000
00000270: 3030 3000 3030 3030 3030 3000 3030 3030  000.0000000.0000
00000280: 3030 3030 3030 3000 3030 3030 3030 3030  0000000.00000000
00000290: 3030 3000 3031 3037 3235 0020 3000 0000  000.010725. 0...
000002a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000002f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000300: 0075 7374 6172 0030 3000 0000 0000 0000  .ustar.00.......
00000310: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000320: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000330: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000340: 0000 0000 0000 0000 0030 3030 3030 3030  .........0000000
00000350: 0030 3030 3030 3030 0000 0000 0000 0000  .0000000........
00000360: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000370: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000380: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000390: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000003f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000400: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000410: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000420: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000430: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000440: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000450: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000460: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000470: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000480: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000490: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000004f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000500: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000510: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000520: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000530: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000540: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000550: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000560: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000570: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000580: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000590: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000005f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000600: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000610: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000620: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000630: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000640: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000650: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000660: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000670: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000680: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000690: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000006f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000700: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000710: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000720: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000730: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000740: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000750: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000760: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000770: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000780: 0000 0000 0000 0000 0000 0000 0000 0000  ................
00000790: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007a0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007b0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007c0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007d0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007e0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
000007f0: 0000 0000 0000 0000 0000 0000 0000 0000  ................

What implementations make of it

In the outcome column, ✅ means that the implementation follows the default policy.

implementationversionoutcomewhat it makes of it
GNU tartar (GNU tar) 1.35✅ rejectserror: tar: Archive contains obsolescent base-64 headers tar: Unexpected EOF in archive tar: Unexpected EOF in archive tar: Error is not recoverable: exiting now
bsdtarbsdtar 3.8.11 - libarchive 3.8.11✅ rejectserror: bsdtar: Error opening archive: Unrecognized archive format
BusyBox tarBusyBox v1.38.0, defconfig⚠️ acceptstree A: a (512 B, 917dba8e)
7-Zip7-Zip (z) 26.05 (x64)✅ rejectserror: ERROR: suite/archives/F51-number-size-plus.tar suite/archives/F51-number-size-plus.tar Open ERROR: Cannot open the file as [tar] archive ERRORS: Is not archive
Python tarfile, filter=data, as in pipCPython 3.15.2⚠️ acceptstree A: a (512 B, 917dba8e)
Python tarfile, filter=tarCPython 3.15.2⚠️ acceptstree A: a (512 B, 917dba8e)
Python tarfile, filter=fully_trustedCPython 3.15.2⚠️ acceptstree A: a (512 B, 917dba8e)
node-tartar 7.5.22⚠️ acceptstree A: a (512 B, 917dba8e)
node-tar, stricttar 7.5.22⚠️ acceptstree A: a (512 B, 917dba8e)
tar-fstar-fs 3.1.3, on tar-stream 3.2.2⚠️ acceptstree A: a (512 B, 917dba8e)
Java Commons CompressCommons Compress 1.28.0, Expander, on Java 27.0.1.0.2✅ rejectserror: java.io.IOException: Corrupted TAR archive.
.NET System.Formats.TarSystem.Formats.Tar of .NET 10.0.14, ExtractToDirectory✅ rejectserror: InvalidDataException: Unable to parse number.
PHP PharData, as in ComposerPharData of PHP 8.5.12, as Composer's TarDownloader calls it✅ rejectserror: UnexpectedValueException: phar error: "suite/archives/F51-number-size-plus.tar" is a corrupted tar file (invalid entry size)
Go containerd archive.Applycontainerd v2.4.2, archive.Apply, of go1.27.3✅ rejectserror: archive/tar: invalid tar header
Rust tartar 0.4.46, unpack⚠️ acceptstree A: a (512 B, 917dba8e)
Rust astral-tokio-tarastral-tokio-tar 0.7.1, unpack⚠️ acceptstree A: a (512 B, 917dba8e)
Rust tar-codec, as in uvtar-codec 0.0.16, with the policies of uv 0.13✅ rejectserror: at byte 0: invalid tar size field: found [43, 48, 48, 48, 48, 48, 48, 49, 48, 48, 48, 0]
RubyGemsRubyGems 4.0.20 of Ruby 4.0.9, extract_tar_gz✅ rejectserror: Gem::Package::TarInvalidError: "+0000001000" is not an octal string
R untar, internalutils::untar of R 4.6.2, tar = "internal"✅ rejectserror: invalid octal digit
Perl Archive::TarArchive::Tar 3.12 of Perl v5.44.0⚠️ acceptstree B: a (0 B, e3b0c442), smuggled (0 B, e3b0c442)
Haskell tartar 0.7.2.0, extract, of GHC 9.14✅ rejectserror: HeaderBadNumericEncoding
Julia Tar.jlTar 1.10.0 of Julia 1.13.3✅ rejectserror: malformed size field: "+0000001000" [header block data]: name = "a\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\…
live-bootstrap untarmescc-tools-extra a151c245e512, as live-bootstrap pins it⚠️ acceptstree A: a (512 B, 917dba8e)
live-bootstrap untar, --non-strictmescc-tools-extra a151c245e512, as live-bootstrap pins it⚠️ acceptstree A: a (512 B, 917dba8e)

Prevalence in release tarballs

The table below shows how many release tarballs have the features of this test case.

ecosystemtarballswith itshare
Spack37,5530none
nixpkgs18,9900none
Guix10,1680none
PyPI10,0000none
crates.io5,0000none
RubyGems5,0000none
live-bootstrap1710none
total (distinct)82,5860none

See also