steady

README

Steady: A simple end-to-end secure logging system

A golang implementation of a proof-of-concept Steady relay and simple echo collector. For the corresponding Steady device please see the C implementation.

Brief instructions to run

1. go get github.com/pylls/steady
2. run steady-relay
3. run steady-make-device
4. copy test.device to the device folder of the C implementation
5. build and run the C demo device
6. run steady-echo-collector to read from the relay

Paper

https://eprint.iacr.org/2018/737

License

Apache 2.0

Documentation

Index

• Constants
• func AuditPath(m int, data [][]byte) [][]byte
• func CheckPayloadHash(payload []byte, policy Policy, bh BlockHeader) bool
• func DecodeBlockPayload(payload, pub, pk []byte, policy Policy, bh BlockHeader) (events [][]byte, IV []byte, err error)
• func EncodePolicy(p Policy) []byte
• func MakeEncodedBlock(index, lenPrev, time uint64, encrypt, compress bool, policy Policy, ...) ([]byte, error)
• func MerkleTreeHash(data [][]byte) (root []byte)
• func RootFromAuditPath(l []byte, index, size int, path [][]byte) (r []byte)
• type BlockHeader
  • func DecodeBlockHeader(encoded []byte, policy Policy) (b BlockHeader, err error)
• type Policy
  • func DecodePolicy(b []byte) (Policy, error)
  • func MakePolicy(sk, vk, pub []byte, timeout, space, time uint64) Policy

Constants

const (
	SetupFilename       = "%s.device"
	DeviceStateFilename = "%s.state"
	CollectorFilename   = "%s.collector"

	WireVersion        = 0x42
	WireIdentifierSize = 32

	// commands
	WireCmdStatus = 0x0
	WireCmdSetup  = 0x1
	WireCmdRead   = 0x2
	WireCmdWrite  = 0x3

	WireTrue    = 0x1
	WireFalse   = 0x0
	WireMore    = 0xA
	WireAuthErr = 0xF

	WirePolicySize      = WireIdentifierSize + lc.VericationKeySize + lc.PublicKeySize + 3*8 + lc.SignatureSize
	WireBlockHeaderSize = 4*8 + 3*lc.HashOutputLen + lc.SignatureSize
	WireAuthSize        = lc.HashOutputLen

	MaxBlockSize = 104857600 // 100 MiB
)

const (
	// LeafPrefix is the domain separation prefix for leaf hashes.
	LeafPrefix = 0x00

	// NodePrefix is the domain separation prefix for internal block nodes.
	NodePrefix = 0x01
)

const IVsize = 32

IVsize is the number of bytes of the random IV per block.

Functions

func AuditPath

func AuditPath(m int, data [][]byte) [][]byte

AuditPath as in RFC6962

func CheckPayloadHash

func CheckPayloadHash(payload []byte, policy Policy, bh BlockHeader) bool

func DecodeBlockPayload

func DecodeBlockPayload(payload, pub, pk []byte, policy Policy, bh BlockHeader) (events [][]byte,
	IV []byte, err error)

func EncodePolicy

func EncodePolicy(p Policy) []byte

func MakeEncodedBlock

func MakeEncodedBlock(index, lenPrev, time uint64,
	encrypt, compress bool,
	policy Policy, events [][]byte, sk []byte) ([]byte, error)

func MerkleTreeHash

func MerkleTreeHash(data [][]byte) (root []byte)

MerkleTreeHash as in RFC6962

func RootFromAuditPath

func RootFromAuditPath(l []byte, index, size int, path [][]byte) (r []byte)

RootFromAuditPath computes the expected root from an audit path

Types

type BlockHeader

type BlockHeader struct {
	Index, LenCur, LenPrev, Time                 uint64
	PayloadHash, HeaderHash, RootHash, Signature []byte
	Encrypted, Compressed                        bool
}

func DecodeBlockHeader

func DecodeBlockHeader(encoded []byte, policy Policy) (b BlockHeader, err error)

type Policy

type Policy struct {
	ID, Signature, Vk, Pub []byte
	Timeout, Space, Time   uint64
}

func DecodePolicy

func DecodePolicy(b []byte) (Policy, error)

func MakePolicy

func MakePolicy(sk, vk, pub []byte,
	timeout, space, time uint64) Policy