Add support for generating ed25519 keys and certs (#1061)

Co-authored-by: Luke Valenta <lvalenta@cloudflare.com>
Co-authored-by: Sofía Celi <cherenkovd69@gmail.com>

bundler/bundle.go

@@ -3,6 +3,7 @@ package bundler
 import (
 	"bytes"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/rsa"
 	"crypto/x509"
 	"crypto/x509/pkix"
@@ -13,6 +14,7 @@ import (
 	"time"
 
 	"github.com/cloudflare/cfssl/helpers"
+	"github.com/cloudflare/cfssl/helpers/derhelpers"
 )
 
 // A Bundle contains a certificate and its trust chain. It is intended
@@ -108,6 +110,8 @@ func (b *Bundle) MarshalJSON() ([]byte, error) {
 		keyType = fmt.Sprintf("%d-bit RSA", keyLength)
 	case x509.DSA:
 		keyType = "DSA"
+	case x509.Ed25519:
+		keyType = "Ed25519"
 	default:
 		keyType = "Unknown"
 	}
@@ -119,6 +123,9 @@ func (b *Bundle) MarshalJSON() ([]byte, error) {
 	case *ecdsa.PrivateKey:
 		keyBytes, _ = x509.MarshalECPrivateKey(key)
 		keyString = PemBlockToString(&pem.Block{Type: "EC PRIVATE KEY", Bytes: keyBytes})
+	case ed25519.PrivateKey:
+		keyBytes, _ = derhelpers.MarshalEd25519PrivateKey(key)
+		keyString = PemBlockToString(&pem.Block{Type: "Ed25519 PRIVATE KEY", Bytes: keyBytes})
 	case fmt.Stringer:
 		keyString = key.String()
 	}

bundler/bundle_from_file_test.go

@@ -260,12 +260,12 @@ var fileTests = []fileTest{
 	},
 
 	// DSA is NOT supported.
-	// Keyless bundling, expect private key error "NotRSAOrECC"
+	// Keyless bundling, expect private key error "NotRSAOrECCOrEd25519"
 	{
 		cert:          certDSA2048,
 		caBundleFile:  testCFSSLRootBundle,
 		intBundleFile: testCFSSLIntBundle,
-		errorCallback: ExpectErrorMessages([]string{`"code":2200,`, `"message":"Private key algorithm is not RSA or ECC"`}),
+		errorCallback: ExpectErrorMessages([]string{`"code":2200,`, `"message":"Private key algorithm is not RSA or ECC or Ed25519"`}),
 	},
 	// Bundling with DSA private key, expect error "Failed to parse private key"
 	{

bundler/bundler.go

@@ -6,6 +6,7 @@ import (
 	"bytes"
 	"crypto"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/rsa"
 	"crypto/tls"
 	"crypto/x509"
@@ -555,7 +556,7 @@ func (b *Bundler) fetchIntermediates(certs []*x509.Certificate) (err error) {
 
 // Bundle takes an X509 certificate (already in the
 // Certificate structure), a private key as crypto.Signer in one of the appropriate
-// formats (i.e. *rsa.PrivateKey or *ecdsa.PrivateKey, or even a opaque key), using them to
+// formats (i.e. *rsa.PrivateKey, *ecdsa.PrivateKey or ed25519.PrivateKey, or even a opaque key), using them to
 // build a certificate bundle.
 func (b *Bundler) Bundle(certs []*x509.Certificate, key crypto.Signer, flavor BundleFlavor) (*Bundle, error) {
 	log.Infof("bundling certificate for %+v", certs[0].Subject)
@@ -576,7 +577,6 @@ func (b *Bundler) Bundle(certs []*x509.Certificate, key crypto.Signer, flavor Bu
 	if key != nil {
 		switch {
 		case cert.PublicKeyAlgorithm == x509.RSA:
-
 			var rsaPublicKey *rsa.PublicKey
 			if rsaPublicKey, ok = key.Public().(*rsa.PublicKey); !ok {
 				return nil, errors.New(errors.PrivateKeyError, errors.KeyMismatch)
@@ -592,15 +592,24 @@ func (b *Bundler) Bundle(certs []*x509.Certificate, key crypto.Signer, flavor Bu
 			if cert.PublicKey.(*ecdsa.PublicKey).X.Cmp(ecdsaPublicKey.X) != 0 {
 				return nil, errors.New(errors.PrivateKeyError, errors.KeyMismatch)
 			}
+		case cert.PublicKeyAlgorithm == x509.Ed25519:
+			var ed25519PublicKey ed25519.PublicKey
+			if ed25519PublicKey, ok = key.Public().(ed25519.PublicKey); !ok {
+				return nil, errors.New(errors.PrivateKeyError, errors.KeyMismatch)
+			}
+			if !(bytes.Equal(cert.PublicKey.(ed25519.PublicKey), ed25519PublicKey)) {
+				return nil, errors.New(errors.PrivateKeyError, errors.KeyMismatch)
+			}
 		default:
-			return nil, errors.New(errors.PrivateKeyError, errors.NotRSAOrECC)
+			return nil, errors.New(errors.PrivateKeyError, errors.NotRSAOrECCOrEd25519)
 		}
 	} else {
 		switch {
 		case cert.PublicKeyAlgorithm == x509.RSA:
 		case cert.PublicKeyAlgorithm == x509.ECDSA:
+		case cert.PublicKeyAlgorithm == x509.Ed25519:
 		default:
-			return nil, errors.New(errors.PrivateKeyError, errors.NotRSAOrECC)
+			return nil, errors.New(errors.PrivateKeyError, errors.NotRSAOrECCOrEd25519)
 		}
 	}
 

cmd/multirootca/ca.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/rsa"
 	"errors"
 	"flag"
@@ -25,7 +26,7 @@ import (
 func parseSigner(root *config.Root) (signer.Signer, error) {
 	privateKey := root.PrivateKey
 	switch priv := privateKey.(type) {
-	case *rsa.PrivateKey, *ecdsa.PrivateKey:
+	case *rsa.PrivateKey, *ecdsa.PrivateKey, ed25519.PrivateKey:
 		s, err := local.NewSigner(priv, root.Certificate, signer.DefaultSigAlgo(priv), nil)
 		if err != nil {
 			return nil, err

csr/csr.go

@@ -4,6 +4,7 @@ package csr
 import (
 	"crypto"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rand"
 	"crypto/rsa"
@@ -13,6 +14,7 @@ import (
 	"encoding/pem"
 	"errors"
 	"fmt"
+	"io"
 	"net"
 	"net/mail"
 	"net/url"
@@ -21,6 +23,7 @@ import (
 
 	cferr "github.com/cloudflare/cfssl/errors"
 	"github.com/cloudflare/cfssl/helpers"
+	"github.com/cloudflare/cfssl/helpers/derhelpers"
 	"github.com/cloudflare/cfssl/log"
 )
 
@@ -64,7 +67,7 @@ func (kr *KeyRequest) Size() int {
 }
 
 // Generate generates a key as specified in the request. Currently,
-// only ECDSA and RSA are supported.
+// only ECDSA, RSA and ed25519 algorithms are supported.
 func (kr *KeyRequest) Generate() (crypto.PrivateKey, error) {
 	log.Debugf("generate key from request: algo=%s, size=%d", kr.Algo(), kr.Size())
 	switch kr.Algo() {
@@ -89,6 +92,12 @@ func (kr *KeyRequest) Generate() (crypto.PrivateKey, error) {
 			return nil, errors.New("invalid curve")
 		}
 		return ecdsa.GenerateKey(curve, rand.Reader)
+	case "ed25519":
+		seed := make([]byte, ed25519.SeedSize)
+		if _, err := io.ReadFull(rand.Reader, seed); err != nil {
+			return nil, err
+		}
+		return ed25519.NewKeyFromSeed(seed), nil
 	default:
 		return nil, errors.New("invalid algorithm")
 	}
@@ -120,6 +129,8 @@ func (kr *KeyRequest) SigAlgo() x509.SignatureAlgorithm {
 		default:
 			return x509.ECDSAWithSHA1
 		}
+	case "ed25519":
+		return x509.PureEd25519
 	default:
 		return x509.UnknownSignatureAlgorithm
 	}
@@ -249,6 +260,17 @@ func ParseRequest(req *CertificateRequest) (csr, key []byte, err error) {
 			Bytes: key,
 		}
 		key = pem.EncodeToMemory(&block)
+	case ed25519.PrivateKey:
+		key, err = derhelpers.MarshalEd25519PrivateKey(priv)
+		if err != nil {
+			err = cferr.Wrap(cferr.PrivateKeyError, cferr.Unknown, err)
+			return
+		}
+		block := pem.Block{
+			Type:  "Ed25519 PRIVATE KEY",
+			Bytes: key,
+		}
+		key = pem.EncodeToMemory(&block)
 	default:
 		panic("Generate should have failed to produce a valid key.")
 	}

csr/csr_test.go

@@ -3,6 +3,7 @@ package csr
 import (
 	"crypto"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rsa"
 	"crypto/x509"
@@ -42,6 +43,10 @@ func TestKeyRequest(t *testing.T) {
 		if kr.Algo() != "ecdsa" {
 			t.Fatal("ECDSA key generated, but expected", kr.Algo())
 		}
+	case ed25519.PrivateKey:
+		if kr.Algo() != "ed25519" {
+			t.Fatal("Ed25519 key generated, but expected", kr.Algo())
+		}
 	}
 }
 
@@ -311,6 +316,21 @@ func TestECGeneration(t *testing.T) {
 	}
 }
 
+func TestED25519Generation(t *testing.T) {
+	kr := &KeyRequest{A: "ed25519"}
+	priv, err := kr.Generate()
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	_, ok := priv.(ed25519.PrivateKey)
+	if !ok {
+		t.Fatal("Expected ed25519 key")
+	}
+	if sa := kr.SigAlgo(); sa == x509.UnknownSignatureAlgorithm {
+		t.Fatal("Invalid signature algorithm!")
+	}
+}
+
 func TestRSAKeyGeneration(t *testing.T) {
 	var rsakey *rsa.PrivateKey
 
@@ -404,6 +424,10 @@ func TestDefaultKeyRequest(t *testing.T) {
 		if DefaultKeyRequest.Algo() != "ecdsa" {
 			t.Fatal("Invalid default key request.")
 		}
+	case "Ed25519 PRIVATE KEY":
+		if DefaultKeyRequest.Algo() != "ed25519" {
+			t.Fatal("Invalid default key request.")
+		}
 	}
 }
 
@@ -430,6 +454,29 @@ func TestRSACertRequest(t *testing.T) {
 	}
 }
 
+// TestED25519CertRequest validates parsing a certificate request with an
+// ED25519 key.
+func TestED25519CertRequest(t *testing.T) {
+	var req = &CertificateRequest{
+		Names: []Name{
+			{
+				C:  "US",
+				ST: "California",
+				L:  "San Francisco",
+				O:  "CloudFlare",
+				OU: "Systems Engineering",
+			},
+		},
+		CN:         "cloudflare.com",
+		Hosts:      []string{"cloudflare.com", "www.cloudflare.com", "jdoe@example.com", "https://www.cloudflare.com"},
+		KeyRequest: &KeyRequest{A: "ed25519"},
+	}
+	_, _, err := ParseRequest(req)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+}
+
 // TestBadCertRequest checks for failure conditions of ParseRequest.
 func TestBadCertRequest(t *testing.T) {
 	var req = &CertificateRequest{

errors/error.go

@@ -113,10 +113,10 @@ const (
 	// these keys.
 	Encrypted Reason = 100 * (iota + 1) //21XX
 
-	// NotRSAOrECC indicates that they key is not an RSA or ECC
+	// NotRSAOrECCOrEd25519 indicates that they key is not an RSA or ECC or Ed25519
 	// private key; these are the only two private key types supported
 	// at this time by CFSSL.
-	NotRSAOrECC //22XX
+	NotRSAOrECCOrEd25519 //22XX
 
 	// KeyMismatch indicates that the private key does not match
 	// the public key or certificate being presented with the key.
@@ -273,8 +273,8 @@ func New(category Category, reason Reason) *Error {
 			msg = "Failed to parse private key"
 		case Encrypted:
 			msg = "Private key is encrypted."
-		case NotRSAOrECC:
-			msg = "Private key algorithm is not RSA or ECC"
+		case NotRSAOrECCOrEd25519:
+			msg = "Private key algorithm is not RSA or ECC or Ed25519"
 		case KeyMismatch:
 			msg = "Private key does not match public key"
 		case GenerationFailed:

errors/error_test.go

@@ -87,7 +87,7 @@ func TestNew(t *testing.T) {
 	if code != 2100 {
 		t.Fatal("Improper error code")
 	}
-	code = New(PrivateKeyError, NotRSAOrECC).ErrorCode
+	code = New(PrivateKeyError, NotRSAOrECCOrEd25519).ErrorCode
 	if code != 2200 {
 		t.Fatal("Improper error code")
 	}

helpers/helpers.go

@@ -6,6 +6,7 @@ import (
 	"bytes"
 	"crypto"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rsa"
 	"crypto/tls"
@@ -61,7 +62,7 @@ var Jul2012 = InclusiveDate(2012, time.July, 01)
 // issuing certificates valid for more than 39 months.
 var Apr2015 = InclusiveDate(2015, time.April, 01)
 
-// KeyLength returns the bit size of ECDSA or RSA PublicKey
+// KeyLength returns the bit size of ECDSA, RSA or Ed25519 PublicKey
 func KeyLength(key interface{}) int {
 	if key == nil {
 		return 0
@@ -70,6 +71,8 @@ func KeyLength(key interface{}) int {
 		return ecdsaKey.Curve.Params().BitSize
 	} else if rsaKey, ok := key.(*rsa.PublicKey); ok {
 		return rsaKey.N.BitLen()
+	} else if _, ok := key.(ed25519.PublicKey); ok {
+		return ed25519.PublicKeySize
 	}
 
 	return 0
@@ -154,12 +157,14 @@ func SignatureString(alg x509.SignatureAlgorithm) string {
 		return "ECDSAWithSHA384"
 	case x509.ECDSAWithSHA512:
 		return "ECDSAWithSHA512"
+	case x509.PureEd25519:
+		return "Ed25519"
 	default:
 		return "Unknown Signature"
 	}
 }
 
-// HashAlgoString returns the hash algorithm name contains in the signature
+// HashAlgoString returns the hash algorithm name contained in the signature
 // method.
 func HashAlgoString(alg x509.SignatureAlgorithm) string {
 	switch alg {
@@ -187,6 +192,8 @@ func HashAlgoString(alg x509.SignatureAlgorithm) string {
 		return "SHA384"
 	case x509.ECDSAWithSHA512:
 		return "SHA512"
+	case x509.PureEd25519:
+		return "Ed25519"
 	default:
 		return "Unknown Hash Algorithm"
 	}
@@ -479,6 +486,8 @@ func SignerAlgo(priv crypto.Signer) x509.SignatureAlgorithm {
 		default:
 			return x509.ECDSAWithSHA1
 		}
+	case ed25519.PublicKey:
+		return x509.PureEd25519
 	default:
 		return x509.UnknownSignatureAlgorithm
 	}