Makwa-Sharp

A pure C# Makwa implementation with no dependencies.

Makwa was a runner up in the Password Hashing Competition, uniquely has a delegation function which allows hashing to be offloaded onto a third party server without revealing the password.

Installation

Nuget

Install-Package Makwa

.NET

dotnet add package Makwa

Git

git clone https://github.com/MitchellBerry/Makwa-Sharp.git

Usage

Basic

using Makwa;

Hasher makwa = Hasher.Create();
String password = "hunter2";
String hash = makwa.HashPassword(password);
// hash: SdVTLgfGKck_b211_TG3Uljw178dpAPtw1qILPA_JMm2w54jILdKKQMp

Verify Password

String hash = "SdVTLgfGKck_b211_TG3Uljw178dpAPtw1qILPA_JMm2w54jILdKKQMp"
bool correct_password = makwa.VerifyPassword(password, hash)

Custom Parameters

makwa.Prehashing = false;
makwa.Posthashing = 16;
makwa.Workfactor = 384;
makwa.Hashfunction = new HMACSHA512();
String hash = makwa.HashPassword(password);
// hash: SdVTLgfGKck_s307_Qh0ZKgAwQr+ieFauHFm4Vg_3B/H3xbYZZa2Ua2yfK55mA

Key Derivation Function Only

byte[] input_bytes = new byte[87]; //[0x00, 0x00, 0x00 ...]
int output_length = 173;
byte[] kdf_output = makwa.KDF(input_bytes, output_length);

Hash Digest Bytes

byte[] salt = new byte[16]; //Use an appropriately random input, 16 bytes long
byte[] password_bytes = Encoding.UTF8.GetBytes(password);
byte[] digest_bytes = makwa.Digest(password_bytes, salt);
// digest byte array, length is determined by Posthashing value

Parameters

Name	Type	Effect	Default
Prehashing	bool	Hashes the input prior to the running the main Makwa algorithm. Allows an unlimited input size.	True
Posthashing	ushort	Hashes the result down to the specified size, the default value of 12 results in a 12 byte digest. A value of 0 applies no post-hashing and the digest will be the full size, values between 1 and 9 are not valid and will raise an exception.	12
Workfactor	uint	The number of rounds performed, a higher number will increase hashing time. Work factors are restricted to values w = x * 2y, where x = 2 or 3 and y ≥ 0, other values will raise an error suggesting the closest valid value. (See notes below)	4096
Hashfunction	HMAC	A HMAC object, only HMACSHA256 and HMACSHA512 are valid options.	HMACSHA256

Testing

Testing is setup for Visual Studio, playlists are provided to reduce testing time rather than going through the full set, TestWorkFactor384 will significantly reduce time taken. Running the full test suite should take ~30 mins on an average cpu. The kats.txt file consists of 400 KDF and 2000 Makwa known answer tests.

Notes

• This implementation enforces specific work factors of the form w = ζ · 2ᵟ, where ζ = 2 or 3, and δ ≥ 0. Some valid work factors: 256, 384, 512, 768, 1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384

• The final hash string doesn't differentiate between SHA-256 and SHA-512. If verifying from an unknown source test both algorithms.

• A unique 2048-bit modulus is generated on first use and stored in the libraries folder as a binary file named modulus, generating your own is possible through either OpenSSL or the MakwaPrivateKey class as is testing for primality and correct type. Modulus must be a Blum integer which is the product of 2 primes p & q of the type: prime ≡ 3 (mod 4).

• A standalone .dll is available here

• The use of Pre and Post hashing affects certain features (delegation and fast-path are unaffected):