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[ca] Fix cross-signing bug where ECDSA keys can't cross-sign RSA CAs #2163

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Merged
aaronlehmann merged 1 commit into from
May 5, 2017
Merged

[ca] Fix cross-signing bug where ECDSA keys can't cross-sign RSA CAs #2163

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7 changes: 4 additions & 3 deletions ca/certificates.go
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Original file line number Diff line number Diff line change
Expand Up @@ -386,16 +386,17 @@ func (rca *RootCA) CrossSignCACertificate(otherCAPEM []byte) ([]byte, error) {
}

// create a new cert with exactly the same parameters, including the public key and exact NotBefore and NotAfter
newCert, err := helpers.ParseCertificatePEM(otherCAPEM)
template, err := helpers.ParseCertificatePEM(otherCAPEM)
if err != nil {
return nil, errors.New("could not parse new CA certificate")
}

if !newCert.IsCA {
if !template.IsCA {
return nil, errors.New("certificate not a CA")
}

derBytes, err := x509.CreateCertificate(cryptorand.Reader, newCert, signer.parsedCert, newCert.PublicKey, signer.cryptoSigner)
template.SignatureAlgorithm = signer.parsedCert.SignatureAlgorithm // make sure we can sign with the signer key
derBytes, err := x509.CreateCertificate(cryptorand.Reader, template, signer.parsedCert, template.PublicKey, signer.cryptoSigner)
if err != nil {
return nil, errors.Wrap(err, "could not cross-sign new CA certificate using old CA material")
}
Expand Down
125 changes: 85 additions & 40 deletions ca/certificates_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@ import (

cfcsr "github.com/cloudflare/cfssl/csr"
"github.com/cloudflare/cfssl/helpers"
"github.com/cloudflare/cfssl/initca"
"github.com/docker/go-events"
"github.com/docker/swarmkit/api"
"github.com/docker/swarmkit/ca"
Expand Down Expand Up @@ -1494,67 +1495,111 @@ func TestValidateCertificateChain(t *testing.T) {
}
}

// Tests cross-signing using a certificate
// Tests cross-signing an RSA cert with an ECDSA cert and vice versa, and an ECDSA
// cert with another ECDSA cert and a RSA cert with another RSA cert
func TestRootCACrossSignCACertificate(t *testing.T) {
t.Parallel()
if cautils.External {
return
}

cert1, key1, err := cautils.CreateRootCertAndKey("rootCN")
require.NoError(t, err)
oldCAs := []struct {
cert, key []byte
}{
{
cert: cautils.ECDSA256SHA256Cert,
key: cautils.ECDSA256Key,
},
{
cert: cautils.RSA2048SHA256Cert,
key: cautils.RSA2048Key,
},
}

rootCA1, err := ca.NewRootCA(cert1, cert1, key1, ca.DefaultNodeCertExpiration, nil)
cert1, key1, err := cautils.CreateRootCertAndKey("rootCNECDSA")
require.NoError(t, err)

cert2, key2, err := cautils.CreateRootCertAndKey("rootCN2")
require.NoError(t, err)
rsaReq := cfcsr.CertificateRequest{
CN: "rootCNRSA",
KeyRequest: &cfcsr.BasicKeyRequest{
A: "rsa",
S: 2048,
},
CA: &cfcsr.CAConfig{Expiry: ca.RootCAExpiration},
}

rootCA2, err := ca.NewRootCA(cert2, cert2, key2, ca.DefaultNodeCertExpiration, nil)
// Generate the CA and get the certificate and private key
cert2, _, key2, err := initca.New(&rsaReq)
require.NoError(t, err)

newCAs := []struct {
cert, key []byte
}{
{
cert: cert1,
key: key1,
},
{
cert: cert2,
key: key2,
},
}

tempdir, err := ioutil.TempDir("", "cross-sign-cert")
require.NoError(t, err)
defer os.RemoveAll(tempdir)
paths := ca.NewConfigPaths(tempdir)
krw := ca.NewKeyReadWriter(paths.Node, nil, nil)

_, _, err = rootCA2.IssueAndSaveNewCertificates(krw, "cn", "ou", "org")
require.NoError(t, err)
certBytes, _, err := krw.Read()
require.NoError(t, err)
leafCert, err := helpers.ParseCertificatePEM(certBytes)
require.NoError(t, err)
for _, oldRoot := range oldCAs {
for _, newRoot := range newCAs {
rootCA1, err := ca.NewRootCA(oldRoot.cert, oldRoot.cert, oldRoot.key, ca.DefaultNodeCertExpiration, nil)
require.NoError(t, err)

// cross-signing a non-CA fails
_, err = rootCA1.CrossSignCACertificate(certBytes)
require.Error(t, err)
rootCA2, err := ca.NewRootCA(newRoot.cert, newRoot.cert, newRoot.key, ca.DefaultNodeCertExpiration, nil)
require.NoError(t, err)

// cross-signing some non-cert PEM bytes fail
_, err = rootCA1.CrossSignCACertificate(key1)
require.Error(t, err)
_, _, err = rootCA2.IssueAndSaveNewCertificates(krw, "cn", "ou", "org")
require.NoError(t, err)
certBytes, keyBytes, err := krw.Read()
require.NoError(t, err)
leafCert, err := helpers.ParseCertificatePEM(certBytes)
require.NoError(t, err)

intermediate, err := rootCA1.CrossSignCACertificate(cert2)
require.NoError(t, err)
parsedIntermediate, err := helpers.ParseCertificatePEM(intermediate)
require.NoError(t, err)
parsedRoot2, err := helpers.ParseCertificatePEM(cert2)
require.NoError(t, err)
require.Equal(t, parsedRoot2.RawSubject, parsedIntermediate.RawSubject)
require.Equal(t, parsedRoot2.RawSubjectPublicKeyInfo, parsedIntermediate.RawSubjectPublicKeyInfo)
require.True(t, parsedIntermediate.IsCA)
// cross-signing a non-CA fails
_, err = rootCA1.CrossSignCACertificate(certBytes)
require.Error(t, err)

intermediatePool := x509.NewCertPool()
intermediatePool.AddCert(parsedIntermediate)
// cross-signing some non-cert PEM bytes fail
_, err = rootCA1.CrossSignCACertificate(keyBytes)
require.Error(t, err)

// we can validate a chain from the leaf to the first root through the intermediate,
// or from the leaf cert to the second root with or without the intermediate
_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA1.Pool})
require.Error(t, err)
_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA1.Pool, Intermediates: intermediatePool})
require.NoError(t, err)
intermediate, err := rootCA1.CrossSignCACertificate(newRoot.cert)
require.NoError(t, err)
parsedIntermediate, err := helpers.ParseCertificatePEM(intermediate)
require.NoError(t, err)
parsedRoot2, err := helpers.ParseCertificatePEM(newRoot.cert)
require.NoError(t, err)
require.Equal(t, parsedRoot2.RawSubject, parsedIntermediate.RawSubject)
require.Equal(t, parsedRoot2.RawSubjectPublicKeyInfo, parsedIntermediate.RawSubjectPublicKeyInfo)
require.True(t, parsedIntermediate.IsCA)

_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA2.Pool})
require.NoError(t, err)
_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA2.Pool, Intermediates: intermediatePool})
require.NoError(t, err)
intermediatePool := x509.NewCertPool()
intermediatePool.AddCert(parsedIntermediate)

// we can validate a chain from the leaf to the first root through the intermediate,
// or from the leaf cert to the second root with or without the intermediate
_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA1.Pool})
require.Error(t, err)
_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA1.Pool, Intermediates: intermediatePool})
require.NoError(t, err)

_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA2.Pool})
require.NoError(t, err)
_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA2.Pool, Intermediates: intermediatePool})
require.NoError(t, err)
}
}
}

func concat(byteSlices ...[]byte) []byte {
Expand Down
101 changes: 55 additions & 46 deletions ca/external_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -33,52 +33,61 @@ func TestExternalCACrossSign(t *testing.T) {
externalCA := secConfig.ExternalCA()
externalCA.UpdateURLs(tc.ExternalSigningServer.URL)

cert2, key2, err := testutils.CreateRootCertAndKey("rootCN2")
require.NoError(t, err)

rootCA2, err := ca.NewRootCA(cert2, cert2, key2, ca.DefaultNodeCertExpiration, nil)
require.NoError(t, err)

krw := ca.NewKeyReadWriter(paths.Node, nil, nil)

_, _, err = rootCA2.IssueAndSaveNewCertificates(krw, "cn", "ou", "org")
require.NoError(t, err)
certBytes, _, err := krw.Read()
require.NoError(t, err)
leafCert, err := helpers.ParseCertificatePEM(certBytes)
require.NoError(t, err)

// we have not enabled CA signing on the external server
_, err = externalCA.CrossSignRootCA(context.Background(), rootCA2)
require.Error(t, err)

require.NoError(t, tc.ExternalSigningServer.EnableCASigning())

intermediate, err := externalCA.CrossSignRootCA(context.Background(), rootCA2)
require.NoError(t, err)

parsedIntermediate, err := helpers.ParseCertificatePEM(intermediate)
require.NoError(t, err)
parsedRoot2, err := helpers.ParseCertificatePEM(cert2)
require.NoError(t, err)
require.Equal(t, parsedRoot2.RawSubject, parsedIntermediate.RawSubject)
require.Equal(t, parsedRoot2.RawSubjectPublicKeyInfo, parsedIntermediate.RawSubjectPublicKeyInfo)
require.True(t, parsedIntermediate.IsCA)

intermediatePool := x509.NewCertPool()
intermediatePool.AddCert(parsedIntermediate)

// we can validate a chain from the leaf to the first root through the intermediate,
// or from the leaf cert to the second root with or without the intermediate
_, err = leafCert.Verify(x509.VerifyOptions{Roots: tc.RootCA.Pool})
require.Error(t, err)
_, err = leafCert.Verify(x509.VerifyOptions{Roots: tc.RootCA.Pool, Intermediates: intermediatePool})
require.NoError(t, err)

_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA2.Pool})
require.NoError(t, err)
_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA2.Pool, Intermediates: intermediatePool})
require.NoError(t, err)
for _, testcase := range []struct{ cert, key []byte }{
{
cert: testutils.ECDSA256SHA256Cert,
key: testutils.ECDSA256Key,
},
{
cert: testutils.RSA2048SHA256Cert,
key: testutils.RSA2048Key,
},
} {
rootCA2, err := ca.NewRootCA(testcase.cert, testcase.cert, testcase.key, ca.DefaultNodeCertExpiration, nil)
require.NoError(t, err)

krw := ca.NewKeyReadWriter(paths.Node, nil, nil)

_, _, err = rootCA2.IssueAndSaveNewCertificates(krw, "cn", "ou", "org")
require.NoError(t, err)
certBytes, _, err := krw.Read()
require.NoError(t, err)
leafCert, err := helpers.ParseCertificatePEM(certBytes)
require.NoError(t, err)

// we have not enabled CA signing on the external server
tc.ExternalSigningServer.DisableCASigning()
_, err = externalCA.CrossSignRootCA(context.Background(), rootCA2)
require.Error(t, err)

require.NoError(t, tc.ExternalSigningServer.EnableCASigning())

intermediate, err := externalCA.CrossSignRootCA(context.Background(), rootCA2)
require.NoError(t, err)

parsedIntermediate, err := helpers.ParseCertificatePEM(intermediate)
require.NoError(t, err)
parsedRoot2, err := helpers.ParseCertificatePEM(testcase.cert)
require.NoError(t, err)
require.Equal(t, parsedRoot2.RawSubject, parsedIntermediate.RawSubject)
require.Equal(t, parsedRoot2.RawSubjectPublicKeyInfo, parsedIntermediate.RawSubjectPublicKeyInfo)
require.True(t, parsedIntermediate.IsCA)

intermediatePool := x509.NewCertPool()
intermediatePool.AddCert(parsedIntermediate)

// we can validate a chain from the leaf to the first root through the intermediate,
// or from the leaf cert to the second root with or without the intermediate
_, err = leafCert.Verify(x509.VerifyOptions{Roots: tc.RootCA.Pool})
require.Error(t, err)
_, err = leafCert.Verify(x509.VerifyOptions{Roots: tc.RootCA.Pool, Intermediates: intermediatePool})
require.NoError(t, err)

_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA2.Pool})
require.NoError(t, err)
_, err = leafCert.Verify(x509.VerifyOptions{Roots: rootCA2.Pool, Intermediates: intermediatePool})
require.NoError(t, err)
}
}

func TestExternalCASignRequestTimesOut(t *testing.T) {
Expand Down