README
¶
Sign-In with Ethereum
This package provides a pure Go implementation of EIP-4361: Sign In With Ethereum.
Installation
SIWE can be easily installed in any Go project by running:
go get -u github.com/spruceid/siwe-go
Usage
SIWE exposes a Message struct which implements EIP-4361.
Parsing a SIWE Message
Parsing is done via the siwe.ParseMessage function:
var message *siwe.Message
var err error
message, err = siwe.ParseMessage(messageStr)
The function will return a nil pointer and an error if there was an issue while parsing.
Verifying and Authenticating a SIWE Message
Verification and Authentication is performed via EIP-191, using the address field of the Message as the expected signer. This returns the Ethereum public key of the signer:
var publicKey *ecdsa.PublicKey
var err error
publicKey, err = message.VerifyEIP191(signature)
The time constraints (expiry and not-before) can also be validated, at current or particular times:
var message *siwe.Message
if message.ValidNow() {
// ...
}
// equivalent to
if message.ValidAt(time.Now().UTC()) {
// ...
}
Combined verification of time constraints and authentication can be done in a single call with verify:
var publicKey *ecdsa.PublicKey
var err error
// Optional nonce variable to be matched against the
// built message struct being verified
var optionalNonce *string
// Optional timestamp variable to verify at any point
// in time, by default it will use `time.Now()`
var optionalTimestamp *time.Time
publicKey, err = message.Verify(signature, optionalNonce, optionalTimestamp)
// If you won't be using nonce matching and want
// to verify the message at current time, it's
// safe to pass `nil` in both arguments
publicKey, err = message.Verify(signature, nil, nil)
Serialization of a SIWE Message
Message instances can also be serialized as their EIP-4361
string representations via the String method:
fmt.Printf("%s", message.String())
Signing Messages from Go code
To sign messages directly from Go code, you will need to do it
like shown below to correctly follow the personal_sign format.
func signHash(data []byte) common.Hash {
msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), data)
return crypto.Keccak256Hash([]byte(msg))
}
func signMessage(message string, privateKey *ecdsa.PrivateKey) ([]byte, error) {
sign := signHash([]byte(message))
signature, err := crypto.Sign(sign.Bytes(), privateKey)
if err != nil {
return nil, err
}
signature[64] += 27
return signature, nil
}
Disclaimer
Our Go library for Sign-In with Ethereum has not yet undergone a formal security audit. We welcome continued feedback on the usability, architecture, and security of this implementation.
See Also
Documentation
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Index ¶
- func GenerateNonce() string
- type ExpiredMessage
- type InvalidMessage
- type InvalidSignature
- type Message
- func (m *Message) GetAddress() common.Address
- func (m *Message) GetChainID() int
- func (m *Message) GetDomain() string
- func (m *Message) GetExpirationTime() *string
- func (m *Message) GetIssuedAt() string
- func (m *Message) GetNonce() string
- func (m *Message) GetNotBefore() *string
- func (m *Message) GetRequestID() *string
- func (m *Message) GetResources() []url.URL
- func (m *Message) GetStatement() *string
- func (m *Message) GetURI() url.URL
- func (m *Message) GetVersion() string
- func (m *Message) String() string
- func (m *Message) ValidAt(when time.Time) (bool, error)
- func (m *Message) ValidNow() (bool, error)
- func (m *Message) Verify(signature string, domain *string, nonce *string, timestamp *time.Time) (*ecdsa.PublicKey, error)
- func (m *Message) VerifyEIP191(signature string) (*ecdsa.PublicKey, error)
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func GenerateNonce ¶
func GenerateNonce() string
Types ¶
type ExpiredMessage ¶
type ExpiredMessage struct {
// contains filtered or unexported fields
}
func (*ExpiredMessage) Error ¶
func (m *ExpiredMessage) Error() string
type InvalidMessage ¶
type InvalidMessage struct {
// contains filtered or unexported fields
}
func (*InvalidMessage) Error ¶
func (m *InvalidMessage) Error() string
type InvalidSignature ¶
type InvalidSignature struct {
// contains filtered or unexported fields
}
func (*InvalidSignature) Error ¶
func (m *InvalidSignature) Error() string
type Message ¶
type Message struct {
// contains filtered or unexported fields
}
func InitMessage ¶
func InitMessage(domain, address, uri, nonce string, options map[string]interface{}) (*Message, error)
InitMessage creates a Message object with the provided parameters
func ParseMessage ¶
ParseMessage returns a Message object by parsing an EIP-4361 formatted string
func (*Message) GetAddress ¶
func (*Message) GetChainID ¶
func (*Message) GetExpirationTime ¶
func (*Message) GetIssuedAt ¶
func (*Message) GetNotBefore ¶
func (*Message) GetRequestID ¶
func (*Message) GetResources ¶
func (*Message) GetStatement ¶
func (*Message) GetVersion ¶
func (*Message) ValidAt ¶
ValidAt validates the time constraints of the message at a specific point in time.
Source Files