open-consul/vendor/github.com/SermoDigital/jose/crypto/rsa.go

81 lines
2.0 KiB
Go

package crypto
import (
"crypto"
"crypto/rand"
"crypto/rsa"
"encoding/json"
)
// SigningMethodRSA implements the RSA family of SigningMethods.
type SigningMethodRSA struct {
Name string
Hash crypto.Hash
_ struct{}
}
// Specific instances of RSA SigningMethods.
var (
// SigningMethodRS256 implements RS256.
SigningMethodRS256 = &SigningMethodRSA{
Name: "RS256",
Hash: crypto.SHA256,
}
// SigningMethodRS384 implements RS384.
SigningMethodRS384 = &SigningMethodRSA{
Name: "RS384",
Hash: crypto.SHA384,
}
// SigningMethodRS512 implements RS512.
SigningMethodRS512 = &SigningMethodRSA{
Name: "RS512",
Hash: crypto.SHA512,
}
)
// Alg implements the SigningMethod interface.
func (m *SigningMethodRSA) Alg() string { return m.Name }
// Verify implements the Verify method from SigningMethod.
// For this signing method, must be an *rsa.PublicKey.
func (m *SigningMethodRSA) Verify(raw []byte, sig Signature, key interface{}) error {
rsaKey, ok := key.(*rsa.PublicKey)
if !ok {
return ErrInvalidKey
}
return rsa.VerifyPKCS1v15(rsaKey, m.Hash, m.sum(raw), sig)
}
// Sign implements the Sign method from SigningMethod.
// For this signing method, must be an *rsa.PrivateKey structure.
func (m *SigningMethodRSA) Sign(data []byte, key interface{}) (Signature, error) {
rsaKey, ok := key.(*rsa.PrivateKey)
if !ok {
return nil, ErrInvalidKey
}
sigBytes, err := rsa.SignPKCS1v15(rand.Reader, rsaKey, m.Hash, m.sum(data))
if err != nil {
return nil, err
}
return Signature(sigBytes), nil
}
func (m *SigningMethodRSA) sum(b []byte) []byte {
h := m.Hash.New()
h.Write(b)
return h.Sum(nil)
}
// Hasher implements the SigningMethod interface.
func (m *SigningMethodRSA) Hasher() crypto.Hash { return m.Hash }
// MarshalJSON implements json.Marshaler.
// See SigningMethodECDSA.MarshalJSON() for information.
func (m *SigningMethodRSA) MarshalJSON() ([]byte, error) {
return []byte(`"` + m.Alg() + `"`), nil
}
var _ json.Marshaler = (*SigningMethodRSA)(nil)