Add support for EdDSA JWT signatures

README.md

@@ -43,6 +43,7 @@ verification as long as any JWTs signed with them are valid.
 The plugin supports a subset of the asymmetric encryption algorithms outlined in the JWT
 specification.
 
+* EdDSA
 * ES256
 * ES384
 * ES512

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/hashicorp/vault/api v1.10.0
 	github.com/hashicorp/vault/sdk v0.10.2
 	github.com/mariuszs/friendlyid-go v0.0.0-20200911181514-555cced97798
+	golang.org/x/crypto v0.12.0
 	gopkg.in/square/go-jose.v2 v2.6.0
 )
 
@@ -65,7 +66,6 @@ require (
 	github.com/ryanuber/go-glob v1.0.0 // indirect
 	github.com/stretchr/testify v1.8.3 // indirect
 	go.uber.org/atomic v1.9.0 // indirect
-	golang.org/x/crypto v0.12.0 // indirect
 	golang.org/x/mod v0.9.0 // indirect
 	golang.org/x/net v0.14.0 // indirect
 	golang.org/x/sys v0.11.0 // indirect

plugin/backend.go

@@ -169,6 +169,8 @@ func (b *backend) getPolicy(ctx context.Context, stg logical.Storage, config *Co
 		default:
 			err = errutil.InternalError{Err: "unsupported RSA key size"}
 		}
+	case jose.EdDSA:
+		polReq.KeyType = keysutil.KeyType_ED25519
 	case jose.ES256:
 		polReq.KeyType = keysutil.KeyType_ECDSA_P256
 	case jose.ES384:

plugin/config.go

@@ -48,7 +48,7 @@ var DefaultAllowedClaims = []string{"sub", "aud"}
 var ReservedClaims = []string{"iss", "exp", "nbf", "iat", "jti"}
 var ReservedHeaders = []string{"kid", "alg", "enc", "zip", "crit"}
 
-var AllowedSignatureAlgorithmNames = []string{string(jose.ES256), string(jose.ES384), string(jose.ES512), string(jose.RS256), string(jose.RS384), string(jose.RS512)}
+var AllowedSignatureAlgorithmNames = []string{string(jose.EdDSA), string(jose.ES256), string(jose.ES384), string(jose.ES512), string(jose.RS256), string(jose.RS384), string(jose.RS512)}
 var AllowedRSAKeyBits = []int{2048, 3072, 4096}
 
 // Config holds all configuration for the backend.
@@ -186,6 +186,8 @@ func (b *backend) saveConfig(ctx context.Context, stg logical.Storage, config *C
 		default:
 			err = errutil.InternalError{Err: "unsupported RSA key size"}
 		}
+	case jose.EdDSA:
+		policy.Type = keysutil.KeyType_ED25519
 	case jose.ES256:
 		policy.Type = keysutil.KeyType_ECDSA_P256
 	case jose.ES384:

plugin/path_jwks.go

@@ -19,10 +19,13 @@ package jwtsecrets
 import (
 	"context"
 	"crypto/x509"
+	"encoding/base64"
 	"encoding/json"
 	"encoding/pem"
 	"github.com/hashicorp/vault/sdk/framework"
+	"github.com/hashicorp/vault/sdk/helper/keysutil"
 	"github.com/hashicorp/vault/sdk/logical"
+	"golang.org/x/crypto/ed25519"
 	"gopkg.in/square/go-jose.v2"
 	"strconv"
 )
@@ -84,6 +87,7 @@ func (b *backend) getPublicKeys(ctx context.Context, stg logical.Storage, mount
 		Keys: make([]jose.JSONWebKey, keyCount),
 	}
 
+	logger := b.Logger()
 	keyIdx := 0
 	for version := policy.MinDecryptionVersion; version <= policy.LatestVersion; version++ {
 
@@ -92,16 +96,26 @@ func (b *backend) getPublicKeys(ctx context.Context, stg logical.Storage, mount
 			continue
 		}
 
-		if key.FormattedPublicKey != "" {
+		if policy.Type == keysutil.KeyType_ED25519 {
+			keyBytes, err := base64.StdEncoding.DecodeString(key.FormattedPublicKey)
+			if err != nil {
+				logger.Error("Failed to decode ED25519 public key", "public_key", key.FormattedPublicKey, "error", err)
+				continue
+			}
+			jwkSet.Keys[keyIdx].Key = ed25519.PublicKey(keyBytes)
+		} else if key.FormattedPublicKey != "" {
 			block, _ := pem.Decode([]byte(key.FormattedPublicKey))
 			if block == nil {
+				logger.Error("Failed to decode PEM key", "public_key", key.FormattedPublicKey)
 				continue
 			}
 
-			jwkSet.Keys[keyIdx].Key, err = x509.ParsePKIXPublicKey(block.Bytes)
+			publicKey, err := x509.ParsePKIXPublicKey(block.Bytes)
 			if err != nil {
+				logger.Error("Failed to parse PKIX public key", "public_key", key.FormattedPublicKey, "error", err)
 				continue
 			}
+			jwkSet.Keys[keyIdx].Key = publicKey
 		} else if key.RSAKey != nil {
 			jwkSet.Keys[keyIdx].Key = &key.RSAKey.PublicKey
 		}

plugin/policy_signer.go

@@ -102,6 +102,9 @@ func (ps *PolicySigner) sign(input []byte) ([]byte, error) {
 		hashType = keysutil.HashTypeSHA2512
 		hash = crypto.SHA512
 		sigAlg = "pkcs1v15"
+	case jose.EdDSA:
+		hashType = keysutil.HashTypeNone
+		sigAlg = ""
 	case jose.ES256:
 		hashType = keysutil.HashTypeSHA2256
 		hash = crypto.SHA256
@@ -120,11 +123,15 @@ func (ps *PolicySigner) sign(input []byte) ([]byte, error) {
 
 	keyVersion := ps.Policy.LatestVersion
 
-	hasher := hash.New()
-
-	// According to documentation, Write() on hash never fails
-	_, _ = hasher.Write(input)
-	hashedInput := hasher.Sum(nil)
+	var hashedInput []byte
+	if hashType == keysutil.HashTypeNone {
+		hashedInput = input
+	} else {
+		hasher := hash.New()
+		// According to documentation, Write() on hash never fails
+		_, _ = hasher.Write(input)
+		hashedInput = hasher.Sum(nil)
+	}
 
 	result, err := ps.Policy.Sign(keyVersion, nil, hashedInput, hashType, sigAlg, keysutil.MarshalingTypeJWS)
 	if err != nil {