hotp 0.1.0

An implementation of the HMAC-based One-time Password (HOTP).

HMAC-based One-time Password (HOTP)

This is an implementation of the HOTP algorithm as specified in RFC 4226.

Installation

dart pub add hotp

Usage

final hotp = Hotp(secret: '12345678901234567890'.codeUnits);

// Generate a HOTP
final password = hotp.generate(counter: 0); // 755224

Base32 encoding

final hotp = Hotp.fromBase32('GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ');

print(hotp.generate(counter: 0)); // 755224

Supported algorithms

• SHA1 - default, as specified in RFC 4226
• SHA256
• SHA512

APIs

Constructor parameters

Name	Type	Description
secret	List<int>	The secret key.
algorithm	Algorithm	The algorithm to use.
digits	int	The number of digits to generate.

If you want to use a Base32 encoded secret, use the fromBase32 constructor.

Name	Type	Description
secret	String	The Base32 encoded secret key.
digits	int	The number of digits to generate.
algorithm	Algorithm	The algorithm to use.
encoding	Encoding	The encoding to use.

Methods

Name	Return type	Description
generate	int	Generates a HOTP for the given counter.
validate	bool	Validates a HOTP for the given counter.

Exported other package types

Name	Type	Description
base32	class	Base32 encoding and decoding util
Encoding	int	Base32 encoding and decoding alg

License

The project is licensed under the MIT license.