/odd-hash

your digesting friend

Primary LanguagePythonGNU General Public License v3.0GPL-3.0

odd-hash: your digesting friend

Simple tools to hash or dictionary attack passwords that use non-standard hash schemes like: sha256(md5(sha1($p).sha3_384($s)).$p).

Why was it made?

There have been a few occasions where I have come across (or wondered in a CTF setting if I had come across) hashing schemes that standard tools such as john or hashcat do not support out of the box. Configuring these tools to deal with non-standard formats is often time consuming and requires digging through lots of documentation, alternatively a throwaway script can be written.

To improve this situation, these tools aim to have a clean user interface for dealing with non-standard formats to allow the user to easily try out different schemes, sadly this does trade lots of efficiency when compared to purpose written crackers.

How to specify

The following are examples of how formats can be specified:

  • md5($p)
  • sha256(sha256($p).sha256_raw($s))
  • sha3_384(md5($s).keccak_512(blake2b_224($p)))
  • hmac_md5($m)
  • sha256(hmac_sha512(keccak_224($s)))

The $p, $s and $m are substituted for the password, salt, and message respectively. Any algorithm can end in _raw, which means its result will be the raw binary hash (i.e. it has not been hexlified). Many of the algorithms can be prefixed with hmac_, the notable exception to this are the sponge based algorithms like sha3 (which are not vulnerable to length extension attack so hmac is of less value).

There are 2 connectives: . and +. These perform concatenation and bitwise xor, respectively. Currently no support has been implemented for padding or truncating values. Finally, There is a special function hex that hexlifies a byte string, while often not required there are some odd formats that need this.

This is a fairly self explanatory specification and was inspired by the way dynamic formats are displayed in john. However there are some differences as the exact format here encodes an algorithm name that is looked up from PyCryptodome's hash library: Crypto.Hash. For this reason, some formats will have an underscore between the digest size and others do not.

The resolution logic works as follows (segments are separated by _):

  1. If the first segment is hmac, remove it (so the second segment is now the first, i.e. the digest algorithm name).

    1. In the case that it was hmac, take the resolved algorithm from the below rules and use it as the digest method in hmac.

  2. If the first segment of the algorithm name is a module in Crypto.Hash. Use that as the algorithm. (e.g. md5 or sha256)

    1. If the second segment is a number, pass this to the new function of the hash algorithm as the digest_bits parameter. (e.g. keccak_256)

  3. If the first two segments of the algorithm form a module in Crypto.Hash. Use that as the algorithm. (e.g. sha3_512)

Limits

First, obviously if the algorithm is not supported by PyCryptodome, then it will not be supported by odd-hash.

Secondly, MAC formats such as CMAC follow a slightly different interface (as a secret/key is passed when instantiating the algorithm). Thus, these are not supported. Due to the usefulness of HMAC special provision has been provided for it.

Finally, both the SHAKE formats follow a slightly different interface in that the digest size is not part of the name or passed to the new function. This has been left as future work to support.

The Tools

Two tools are provided:

  • odd-hash used for hashing a password [usage] [examples]
  • odd-crack used for dictionary attack against a hash (or regex) [usage] [examples]

Install

From pypi.org:

pip3 install oddhash

From source:

pip3 install -r requirements.txt
python3 setup.py install

odd-hash usage

$ odd-hash -h
usage: odd-hash [-h] [--salt S] [--message M] [--debug] [--raw] format password

  Configurable password hasher. It is designed to be easy to
  generate different format hashes using a standard hash
  specification similar to what is often shown in PHP.

  Selection of supported hash algorithms depends on what is
  available in the installed version of pycryptodome. See
  following link for more details:

  https://pycryptodome.readthedocs.io/en/latest/src/hash/hash.html

  Currently it is not possible to use this tool for any of the
  algorithms that use a different interface, such either of the
  SHAKEs or the MAC algorithms (with the exception of HMAC). To
  better understand, compare the usage of these with MD5 on the
  above link.

  Parameters such as salt and message can be specified with a
  prefix of: hex, base64, base64urlsafe, utf8.

positional arguments:
  format       Hash format specification, e.g. "md5($p)" or
               something much more complex such
               as "sha3_384(md5($s).keccak_512(blake2b_224($p)))".

               Any of the algorithm names can be given the suffix
               with "_raw", which does not convert the resulting
               hash back into base16 before the next hash. E.g.
               "sha256(sha256_raw($p))" will hash the resulting
               32 bytes of the first hash (instead of turning
               them into hex first, i.e. 64 chars).

               It is possible to prefix algorithm names
               with "hmac_". This will use the password value as
               the secret and value passed in between the
               parameters as the message. E.g.
               "hmac_sha256($m)" or
               even "sha256(hmac_md5($s.sha1($p)))" is
               possible. Be aware that not all possible
               combinations of hmac and digest algorithms are
               supported, this is especially true of sponge based
               algorithms (e.g. sha3, keccak, blake2b).

               The following is a list of hash functions
               available from the installed version of
               pycryptodome: BLAKE2b, BLAKE2s, CMAC, HMAC, MD2,
               MD4, MD5, Poly1305, RIPEMD, RIPEMD160, SHA, SHA1,
               SHA224, SHA256, SHA384, SHA3_224, SHA3_256,
               SHA3_384, SHA3_512, SHA512, SHAKE128, SHAKE256,
               keccak.

  password     The password to hash


optional arguments:
  -h, --help   show this help message and exit

  --salt S     If needed, specify a salt value: $s

  --message M  If needed, specify a message value: $m

  --debug      Increase verbosity of print messages

  --raw        Dont try and convert hash to utf8 before printing.


  oddhash v0.0.6. Copyright (C) 2021 Karim Kanso. All Rights Reserved.

odd-hash examples

$ odd-hash 'md5($p)' 'password123'
482c811da5d5b4bc6d497ffa98491e38

$ odd-hash 'md5($p.sha256($s))' --salt oddhash 'password123'
86e2e5671b8b7f9f6264ecd6d1d749c3

$ odd-hash 'md5($p.sha256($s))' --salt hex:6f646468617368 'password123'
86e2e5671b8b7f9f6264ecd6d1d749c3

$ odd-hash 'md5($p.sha256($s))' --salt base64:b2RkaGFzaA== 'password123'
86e2e5671b8b7f9f6264ecd6d1d749c3

$ odd-hash 'keccak_256(keccak_256_raw($p))' 'password123'
7e7471197b18c087ce6fd7abdcd1991481eb650e39cb0eeafc82cfb7186c0cfe

$ odd-hash 'hmac_sha256($m)' --message 'gjdkdkic894m' 'password123'
7de36a5d1374d690ebe19d42be1e89023fe1f7548f38fa0eae89dc91bd8901dd

$ odd-hash 'hex(sha1_raw($p)+sha1_raw($s.sha1_raw(sha1_raw($p))))' password --salt hex:304a5f7d3066515a69015c49637d45712d3e0154
99dd12ac6830335ab844a97ea78aacb94aa1f4ee

odd-crack usage

$ odd-crack -h
usage: odd-crack [-h] [--salt S] [--message M] [--debug] format wordlist HASH [HASH ...]

  Configurable password hash cracker. It is designed to be easy
  to specify different format hashes, however it is not designed
  to be fast. The tool was created as often serious password
  crackers (e.g. john or hashcat) can be time consuming to use a
  format that is not pre-configured.

  Selection of supported hash algorithms depends on what is
  available in the installed version of pycryptodome. See
  following link for more details:

  https://pycryptodome.readthedocs.io/en/latest/src/hash/hash.html

  Currently it is not possible to use this tool for any of the
  algorithms that use a different interface, such either of the
  SHAKEs or the MAC algorithms (with the exception of HMAC). To
  better understand, compare the usage of these with MD5 on the
  above link.

  Parameters such as salt, message and hashes can be specified
  with a prefix of: hex, base64, base64urlsafe, utf8.

positional arguments:
  format       Hash format specification, e.g. "md5($p)" or
               something much more complex such
               as "sha3_384(md5($s).keccak_512(blake2b_224($p)))".

               Any of the algorithm names can be given the suffix
               with "_raw", which does not convert the resulting
               hash back into base16 before the next hash. E.g.
               "sha256(sha256_raw($p))" will hash the resulting
               32 bytes of the first hash (instead of turning
               them into hex first, i.e. 64 chars).

               It is possible to prefix algorithm names
               with "hmac_". This will use the password value as
               the secret and value passed in between the
               parameters as the message. E.g.
               "hmac_sha256($m)" or
               even "sha256(hmac_md5($s.sha1($p)))" is
               possible. Be aware that not all possible
               combinations of hmac and digest algorithms are
               supported, this is especially true of sponge based
               algorithms (e.g. sha3, keccak, blake2b).

               The following is a list of hash functions
               available from the installed version of
               pycryptodome: BLAKE2b, BLAKE2s, CMAC, HMAC, MD2,
               MD4, MD5, Poly1305, RIPEMD, RIPEMD160, SHA, SHA1,
               SHA224, SHA256, SHA384, SHA3_224, SHA3_256,
               SHA3_384, SHA3_512, SHA512, SHAKE128, SHAKE256,
               keccak.

  wordlist     Wordlist to use for cracking

  HASH         List of base16 (i.e. hex) hashes to attempt to
               crack. Caution, no validation is performed on the
               length. Supports "base64:" prefix.

               If a hash begins with "@" then it will be treated
               as a file and hashes read from it.

               If a hash starts with "regex:" then it is used to
               match against computed hashes. All comparisons are
               done in lowercase hex. E.g. "regex:^0e\d+$" to
               find a hash vulnerable to php type juggling.


optional arguments:
  -h, --help   show this help message and exit

  --salt S     If needed, specify a salt value: $s

  --message M  If needed, specify a message value: $m

  --debug      Increase verbosity of print messages


  oddhash v0.0.6. Copyright (C) 2021 Karim Kanso. All Rights Reserved.

odd-crack examples

While its possible to crack a simple md5 hash as follows, there are many other more efficient tools:

$ odd-crack 'md5($p)' rockyou.txt  482c811da5d5b4bc6d497ffa98491e38
[*] loading file...
[*] found password123=482c811da5d5b4bc6d497ffa98491e38
[*] all hashes found, shutdown requested
[*] done, tried 1384 passwords

$ odd-crack 'keccak_256(keccak_256_raw($p))' rockyou.txt 7e7471197b18c087ce6fd7abdcd1991481eb650e39cb0eeafc82cfb7186c0cfe
[*] loading file...
[*] found password123=7e7471197b18c087ce6fd7abdcd1991481eb650e39cb0eeafc82cfb7186c0cfe
[*] all hashes found, shutdown requested
[*] done, tried 1384 passwords

$ odd-crack 'hmac_sha256($m)' --message base64:t4ErHzCg4EaGujcalk2WWg== rockyou.txt base64:UmUuTPTBS3PaOkQGqvubvkYWUA1m2q1QmqUkk7Y/Nbw=
[*] loading file...
[*] found password123=52652e4cf4c14b73da3a4406aafb9bbe4616500d66daad509aa52493b63f35bc
[*] all hashes found, shutdown requested
[*] done, tried 1384 passwords

The following can be used to crack a mysql_native_password captured challenge response:

$ odd-crack 'hex(sha1_raw($p)+sha1_raw($s.sha1_raw(sha1_raw($p))))' --salt hex:304a5f7d3066515a69015c49637d45712d3e0154 rockyou.txt 99dd12ac6830335ab844a97ea78aacb94aa1f4ee
[*] loading file...
[*] found password=99dd12ac6830335ab844a97ea78aacb94aa1f4ee
[*] all hashes found, shutdown requested
[*] done, tried 4 passwords

Other bits

Source code can be found on GitHub.

Copyright (C) 2021 Karim Kanso. All Rights Reserved. Project licensed under GPLv3.