jwt/ed25519.go

82 lines
1.9 KiB
Go

package jwt
import (
"errors"
"crypto/ed25519"
)
var (
ErrEd25519Verification = errors.New("ed25519: verification error")
)
// Implements the EdDSA family
// Expects ed25519.PrivateKey for signing and ed25519.PublicKey for verification
type SigningMethodEd25519 struct{}
// Specific instance for EdDSA
var (
SigningMethodEdDSA *SigningMethodEd25519
)
func init() {
SigningMethodEdDSA = &SigningMethodEd25519{}
RegisterSigningMethod(SigningMethodEdDSA.Alg(), func() SigningMethod {
return SigningMethodEdDSA
})
}
func (m *SigningMethodEd25519) Alg() string {
return "EdDSA"
}
// Implements the Verify method from SigningMethod
// For this verify method, key must be an ed25519.PublicKey
func (m *SigningMethodEd25519) Verify(signingString, signature string, key interface{}) error {
var err error
var ed25519Key ed25519.PublicKey
var ok bool
if ed25519Key, ok = key.(ed25519.PublicKey); !ok {
return ErrInvalidKeyType
}
if len(ed25519Key) != ed25519.PublicKeySize {
return ErrInvalidKey
}
// Decode the signature
var sig []byte
if sig, err = DecodeSegment(signature); err != nil {
return err
}
// Verify the signature
if !ed25519.Verify(ed25519Key, []byte(signingString), sig) {
return ErrEd25519Verification
}
return nil
}
// Implements the Sign method from SigningMethod
// For this signing method, key must be an ed25519.PrivateKey
func (m *SigningMethodEd25519) Sign(signingString string, key interface{}) (string, error) {
var ed25519Key ed25519.PrivateKey
var ok bool
if ed25519Key, ok = key.(ed25519.PrivateKey); !ok {
return "", ErrInvalidKeyType
}
// ed25519.Sign panics if private key not equal to ed25519.PrivateKeySize
// this allows to avoid recover usage
if len(ed25519Key) != ed25519.PrivateKeySize {
return "", ErrInvalidKey
}
// Sign the string and return the encoded result
sig := ed25519.Sign(ed25519Key, []byte(signingString))
return EncodeSegment(sig), nil
}