pwnlib.libcdb — Libc Database

Fetch a LIBC binary based on some heuristics.

pwnlib.libcdb.get_build_id_offsets()[source]

Returns a list of file offsets where the Build ID should reside within an ELF file of the currently selected architecture.

pwnlib.libcdb.search_by_build_id(hex_encoded_id, unstrip=True)[source]

Given a hex-encoded Build ID, attempt to download a matching libc from libcdb.

Parameters:
  • hex_encoded_id (str) – Hex-encoded Build ID (e.g. ‘ABCDEF…’) of the library
  • unstrip (bool) – Try to fetch debug info for the libc and apply it to the downloaded file.
Returns:

Path to the downloaded library on disk, or None.

Examples

>>> filename = search_by_build_id('fe136e485814fee2268cf19e5c124ed0f73f4400')
>>> hex(ELF(filename).symbols.read)
'0xda260'
>>> None == search_by_build_id('XX')
True
>>> filename = search_by_build_id('a5a3c3f65fd94f4c7f323a175707c3a79cbbd614')
>>> hex(ELF(filename).symbols.read)
'0xeef40'
pwnlib.libcdb.search_by_sha1(hex_encoded_id, unstrip=True)[source]

Given a hex-encoded sha1, attempt to download a matching libc from libcdb.

Parameters:
  • hex_encoded_id (str) – Hex-encoded sha1sum (e.g. ‘ABCDEF…’) of the library
  • unstrip (bool) – Try to fetch debug info for the libc and apply it to the downloaded file.
Returns:

Path to the downloaded library on disk, or None.

Examples

>>> filename = search_by_sha1('34471e355a5e71400b9d65e78d2cd6ce7fc49de5')
>>> hex(ELF(filename).symbols.read)
'0xda260'
>>> None == search_by_sha1('XX')
True
>>> filename = search_by_sha1('0041d2f397bc2498f62aeb4134d522c5b2635e87')
>>> hex(ELF(filename).symbols.read)
'0xeef40'
pwnlib.libcdb.search_by_sha256(hex_encoded_id, unstrip=True)[source]

Given a hex-encoded sha256, attempt to download a matching libc from libcdb.

Parameters:
  • hex_encoded_id (str) – Hex-encoded sha256sum (e.g. ‘ABCDEF…’) of the library
  • unstrip (bool) – Try to fetch debug info for the libc and apply it to the downloaded file.
Returns:

Path to the downloaded library on disk, or None.

Examples

>>> filename = search_by_sha256('5e877a8272da934812d2d1f9ee94f73c77c790cbc5d8251f5322389fc9667f21')
>>> hex(ELF(filename).symbols.read)
'0xda260'
>>> None == search_by_sha256('XX')
True
>>> filename = search_by_sha256('5d78fc60054df18df20480c71f3379218790751090f452baffb62ac6b2aff7ee')
>>> hex(ELF(filename).symbols.read)
'0xeef40'
pwnlib.libcdb.search_by_md5(hex_encoded_id, unstrip=True)[source]

Given a hex-encoded md5sum, attempt to download a matching libc from libcdb.

Parameters:
  • hex_encoded_id (str) – Hex-encoded md5sum (e.g. ‘ABCDEF…’) of the library
  • unstrip (bool) – Try to fetch debug info for the libc and apply it to the downloaded file.
Returns:

Path to the downloaded library on disk, or None.

Examples

>>> filename = search_by_md5('7a71dafb87606f360043dcd638e411bd')
>>> hex(ELF(filename).symbols.read)
'0xda260'
>>> None == search_by_md5('XX')
True
>>> filename = search_by_md5('74f2d3062180572fc8bcd964b587eeae')
>>> hex(ELF(filename).symbols.read)
'0xeef40'
pwnlib.libcdb.unstrip_libc(filename)[source]

Given a path to a libc binary, attempt to download matching debug info and add them back to the given binary.

This modifies the given file.

Parameters:filename (str) – Path to the libc binary to unstrip.
Returns:True if binary was unstripped, False otherwise.

Examples

>>> filename = search_by_build_id('2d1c5e0b85cb06ff47fa6fa088ec22cb6e06074e', unstrip=False)
>>> libc = ELF(filename)
>>> hex(libc.symbols.read)
'0xe56c0'
>>> 'main_arena' in libc.symbols
False
>>> unstrip_libc(filename)
True
>>> libc = ELF(filename)
>>> hex(libc.symbols.main_arena)
'0x1d57a0'
>>> unstrip_libc(which('python'))
False
>>> filename = search_by_build_id('06a8004be6e10c4aeabbe0db74423ace392a2d6b', unstrip=True)
>>> 'main_arena' in ELF(filename).symbols
True