xmss

README

XMSS: eXtended Merkle Signature Scheme

This project implements RFC8391, the eXtended Merkle Signature Scheme (XMSS), a hash-based digital signature system that can so far withstand known attacks using quantum computers. This repostiory contains code implementing the single-tree scheme, namely the following parameter sets (see section 5.3. for reference):

Name	Functions	n	w	len	h
SHA2_10_256	SHA2-256	32	16	67	10
SHA2_16_256	SHA2-256	32	16	67	16
SHA2_20_256	SHA2-256	32	16	67	20

This code has no dependencies and is compatible with the official C implementation assuming the appropriate settings (see above) are presumed.

Install

• Run go get https://github.com/danielhavir/go-xmss

Example

package main

import (
    "fmt"
    "github.com/danielhavir/go-xmss"
)

func main() {
    params := xmss.SHA2_16_256
    
    prv, pub := xmss.GenerateXMSSKeypar(params)

    msg := ...

    sig := prv.Sign(params, msg)

    m := make([]byte, params.SignBytes()+len(msg))

    if xmss.Verify(params, m, *sig, *pub) {
        fmt.Println("Signature matches.")
    } else {
        fmt.Println("Verification does not match.")
    }
}

References

• XMSS: eXtended Merkle Signature Scheme RFC8391
• Official reference C implementation

Documentation

Index

• Variables
• func GenerateXMSSKeypair(params *Params) (*PrivateXMSS, *PublicXMSS)
• func Verify(params *Params, m, signature []byte, pub PublicXMSS) (match bool)
• type Params
  • func (params *Params) SignBytes() int
• type PrivateXMSS
  • func (prv PrivateXMSS) Sign(params *Params, m []byte) *SignatureXMSS
• type PublicXMSS
• type SignatureXMSS

Variables

var (
	// SHA2_10_256 is parameter set using SHA-256 with n = 32, w = 16 and a Merkle Tree of height 10
	SHA2_10_256 = initParams(32, 16, 10)
	// SHA2_16_256 is parameter set using SHA-256 with n = 32, w = 16 and a Merkle Tree of height 16
	SHA2_16_256 = initParams(32, 16, 16)
	// SHA2_20_256 is parameter set using SHA-256 with n = 32, w = 16 and a Merkle Tree of height 20
	SHA2_20_256 = initParams(32, 16, 20)
)

Functions

func GenerateXMSSKeypair

func GenerateXMSSKeypair(params *Params) (*PrivateXMSS, *PublicXMSS)

GenerateXMSSKeypair Section 4.1.7. Algorithm 10: XMSS_keyGen - Generate an XMSS key pair Generates a XMSS key pair for a given parameter set. Format private: [(32bit) index || prvSeed || seed || pubSeed || root] Format public: [root || pubSeed]

func Verify

func Verify(params *Params, m, signature []byte, pub PublicXMSS) (match bool)

Verify Section 4.1.10. Algorithm 14: XMSS_verify - Verify an XMSS signature using the corresponding XMSS public key and a message Verifies a given message signature pair under a given public key. Note that this assumes a pk without an OID, i.e. [root || pubSeed]

Types

type Params

type Params struct {
	// contains filtered or unexported fields
}

Params is a struct for parameters

func (*Params) SignBytes

func (params *Params) SignBytes() int

SignBytes the length of the signature based on a given parameter set

type PrivateXMSS

type PrivateXMSS []byte

PrivateXMSS key

func (PrivateXMSS) Sign

func (prv PrivateXMSS) Sign(params *Params, m []byte) *SignatureXMSS

Sign Section 4.1.9. Algorithm 12: XMSS_sign - Generate an XMSS signature and update the XMSS private key Signs a message. Returns an array containing the signature followed by the message and an updated secret key.

type PublicXMSS

type PublicXMSS []byte

PublicXMSS key

type SignatureXMSS

type SignatureXMSS []byte

SignatureXMSS struct