guniorobot/fshp-is-not-secure-anymore

Fairly Secure Hashed Password

FSHP: Fairly Secure Hashed Password

What is FSHP?

Fairly Secure Hashed Password (FSHP) is a salted, iteratively hashed password hashing implementation.

Design principle is similar with PBKDF1 specification in RFC 2898 (a.k.a: PKCS #5: Password-Based Cryptography Specification Version 2.0)

FSHP allows choosing the salt length, number of iterations and the underlying cryptographic hash function among SHA-1 and SHA-2 (256, 384, 512).

Security

Default FSHP1 uses 8 byte salts, with 4096 iterations of SHA-256 hashing.

• 8 byte salt renders rainbow table attacks impractical by multiplying the required space with 2^64.
• 4096 iterations causes brute force attacks to be fairly expensive.
• There are no known attacks against SHA-256 to find collisions with a computational effort of fewer than 2^128 operations at the time of this release.

Implementations

• Python: Tested with 2.3.5 (w/ hashlib), 2.5.1, 2.6.1

  Available in PyPI. http://pypi.python.org/pypi/fshp

  Install: easy_install fshp

• Ruby : Tested with 1.8.6

  Available in RubyForge. http://rubyforge.org/projects/fshp/

  Install: gem install fshp

• Perl : Tested with 5.8.8

  Available in CPAN http://search.cpan.org/~bdd/Crypt-FSHP/

  Install: perl -MCPAN -e 'install Crypt::FSHP'

• PHP5 : Tested with 5.2.6

• Java : Tested with 1.4, 1.5, 1.6. Dependency: Apache Commons - Codec (Base64)

• JavaScript: SHA-1 and SHA-256 support only. Tested with Safari 4, Firefox 3.0.

Everyone is more than welcome to create missing language implementations or polish the current ones.

Basic Operation

Calling crypt() with a single parameter of cleartext password, implies the default configuration of FSHP1.

• salt length: 8 bytes long random salt will be generated.
• hash rounds: 4096 iterations of hashing will be applied in output chaining mode.
• FSHP variant: Variant 1 uses SHA-256 as underlying hash function.

>>> hashed_pw = fshp.crypt('OrpheanBeholderScryDoubt')
>>> print hashed_pw
{FSHP1|8|4096}GVSUFDAjdh0vBosn1GUhzGLHP7BmkbCZVH/3TQqGIjADXpc+6NCg3g==
>>> fshp.check('OrpheanBeholderScryDoubt', hashed_pw)
True

Customizing the Crypt

Let's set a higher password storage security baseline.

• Increase the salt length from default 8 to 16.
• Increase the hash rounds from default 4096 to 8192.
• Select FSHP3 with SHA-512 as the underlying hash algorithm.

>>> hashed_pw = fshp.crypt('ExecuteOrder66', saltlen=16, rounds=8192, variant=3)
>>> print hashed_pw
{FSHP3|16|8192}0aY7rZQ+/PR+Rd5/I9ssRM7cjguyT8ibypNaSp/U1uziNO3BVlg5qPUng+zHUDQC3ao/JbzOnIBUtAeWHEy7a2vZeZ7jAwyJJa2EqOsq4Io=