package dsse

import "github.com/secure-systems-lab/go-securesystemslib/dsse"

Package dsse implements the Dead Simple Signing Envelope (DSSE) https://github.com/secure-systems-lab/dsse

Index

Variables 

var ErrNoSignature = errors.New("no signature found")

ErrNoSignature indicates that an envelope did not contain any signatures. 

var ErrNoSigners = errors.New("no signers provided")

ErrNoSigners indicates that no signer was provided. 

var ErrUnknownKey = errors.New("unknown key")

ErrUnknownKey indicates that the implementation does not recognize the key.

Functions

func PAE 

func PAE(payloadType string, payload []byte) []byte

PAE implementes the DSSE Pre-Authentic Encoding https://github.com/secure-systems-lab/dsse/blob/master/protocol.md#signature-definition

func SHA256KeyID 

func SHA256KeyID(pub crypto.PublicKey) (string, error)

Types

type AcceptedKey 

type AcceptedKey struct {
	Public crypto.PublicKey
	KeyID  string
	Sig    Signature
}

type Envelope 

type Envelope struct {
	PayloadType string      `json:"payloadType"`
	Payload     string      `json:"payload"`
	Signatures  []Signature `json:"signatures"`
}

Envelope captures an envelope as described by the Secure Systems Lab Signing Specification. See here: https://github.com/secure-systems-lab/signing-spec/blob/master/envelope.md

func (*Envelope) DecodeB64Payload 

func (e *Envelope) DecodeB64Payload() ([]byte, error)

DecodeB64Payload returns the serialized body, decoded from the envelope's payload field. A flexible decoder is used, first trying standard base64, then URL-encoded base64.

type EnvelopeSigner 

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

EnvelopeSigner creates signed Envelopes.

func NewEnvelopeSigner 

func NewEnvelopeSigner(p ...SignVerifier) (*EnvelopeSigner, error)

NewEnvelopeSigner creates an EnvelopeSigner that uses 1+ Signer algorithms to sign the data. Creates a verifier with threshold=1, at least one of the providers must validate signitures successfully.

func NewMultiEnvelopeSigner 

func NewMultiEnvelopeSigner(threshold int, p ...SignVerifier) (*EnvelopeSigner, error)

NewMultiEnvelopeSigner creates an EnvelopeSigner that uses 1+ Signer algorithms to sign the data. Creates a verifier with threshold. threashold indicates the amount of providers that must validate the envelope.

func (*EnvelopeSigner) SignPayload 

func (es *EnvelopeSigner) SignPayload(ctx context.Context, payloadType string, body []byte) (*Envelope, error)

SignPayload signs a payload and payload type according to DSSE. Returned is an envelope as defined here: https://github.com/secure-systems-lab/dsse/blob/master/envelope.md One signature will be added for each Signer in the EnvelopeSigner.

func (*EnvelopeSigner) Verify 

func (es *EnvelopeSigner) Verify(ctx context.Context, e *Envelope) ([]AcceptedKey, error)

Verify decodes the payload and verifies the signature. Any domain specific validation such as parsing the decoded body and validating the payload type is left out to the caller. Verify returns a list of accepted keys each including a keyid, public and signiture of the accepted provider keys.

type EnvelopeVerifier 

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

func NewEnvelopeVerifier 

func NewEnvelopeVerifier(v ...Verifier) (*EnvelopeVerifier, error)

func NewMultiEnvelopeVerifier 

func NewMultiEnvelopeVerifier(threshold int, p ...Verifier) (*EnvelopeVerifier, error)

func (*EnvelopeVerifier) Verify 

func (ev *EnvelopeVerifier) Verify(ctx context.Context, e *Envelope) ([]AcceptedKey, error)

type SignVerifier 

type SignVerifier interface {
	Signer
	Verifier
}

SignVerifer provides both the signing and verification interface.

type Signature 

type Signature struct {
	KeyID string `json:"keyid"`
	Sig   string `json:"sig"`
}

Signature represents a generic in-toto signature that contains the identifier of the key which was used to create the signature. The used signature scheme has to be agreed upon by the signer and verifer out of band. The signature is a base64 encoding of the raw bytes from the signature algorithm.

type Signer 

type Signer interface {
	Sign(ctx context.Context, data []byte) ([]byte, error)
	KeyID() (string, error)
}

Signer defines the interface for an abstract signing algorithm. The Signer interface is used to inject signature algorithm implementations into the EnevelopeSigner. This decoupling allows for any signing algorithm and key management system can be used. The full message is provided as the parameter. If the signature algorithm depends on hashing of the message prior to signature calculation, the implementor of this interface must perform such hashing. The function must return raw bytes representing the calculated signature using the current algorithm, and the key used (if applicable). For an example see EcdsaSigner in sign_test.go.

type Verifier 

type Verifier interface {
	Verify(ctx context.Context, data, sig []byte) error
	KeyID() (string, error)
	Public() crypto.PublicKey
}

Verifier verifies a complete message against a signature and key. If the message was hashed prior to signature generation, the verifier must perform the same steps. If KeyID returns successfully, only signature matching the key ID will be verified.

Source Files

sign.go verify.go

Version
v0.5.0
Published
Feb 14, 2023
Platform
js/wasm
Imports
6 packages
Last checked
10 months ago –

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