zitadel-oidc/pkg/crypto/hash.go
2024-08-19 20:57:07 +03:00

51 lines
1.4 KiB
Go

package crypto
import (
"crypto/sha256"
"crypto/sha512"
"encoding/base64"
"errors"
"fmt"
"hash"
jose "github.com/go-jose/go-jose/v4"
)
var ErrUnsupportedAlgorithm = errors.New("unsupported signing algorithm")
func GetHashAlgorithm(sigAlgorithm jose.SignatureAlgorithm) (hash.Hash, error) {
switch sigAlgorithm {
case jose.RS256, jose.ES256, jose.PS256:
return sha256.New(), nil
case jose.RS384, jose.ES384, jose.PS384:
return sha512.New384(), nil
case jose.RS512, jose.ES512, jose.PS512:
return sha512.New(), nil
// There is no published spec for this yet.
// There is consensus here: https://bitbucket.org/openid/connect/issues/1125/_hash-algorithm-for-eddsa-id-tokens
// Currently go-jose only supports the ed25519 curve key for EdDSA, so we can safely assume sha512 here.
//
// TODO: When go-jose ever decides to support ed448, we need to know the "crv" parameter and use shake256 for ed448.
// The "crv" value is currently not exposed by go-jose.JSONWebKey and is currently only hard-coded to be set during marshalling.
case jose.EdDSA:
return sha512.New(), nil
default:
return nil, fmt.Errorf("%w: %q", ErrUnsupportedAlgorithm, sigAlgorithm)
}
}
func HashString(hash hash.Hash, s string, firstHalf bool) string {
if hash == nil {
return s
}
//nolint:errcheck
hash.Write([]byte(s))
size := hash.Size()
if firstHalf {
size = size / 2
}
sum := hash.Sum(nil)[:size]
return base64.RawURLEncoding.EncodeToString(sum)
}