func (rb *repoBuilder) bytesToSignedAndValidateSigs(role data.BaseRole, content []byte) (*data.Signed, error) {
signedObj, err := rb.bytesToSigned(content, role.Name)
if err != nil {
return nil, err
}
// verify signature
if err := signed.VerifySignatures(signedObj, role); err != nil {
return nil, err
}
return signedObj, nil
}
// This changes the root key
func TestSwizzlerChangeRootKey(t *testing.T) {
f, origMeta := createNewSwizzler(t)
err := f.ChangeRootKey()
require.NoError(t, err)
// we want to test these in a specific order
roles := []string{data.CanonicalRootRole, data.CanonicalTargetsRole, data.CanonicalSnapshotRole,
data.CanonicalTimestampRole, "targets/a", "targets/a/b"}
for _, role := range roles {
origMeta := origMeta[role]
newMeta, err := f.MetadataCache.GetMeta(role, store.NoSizeLimit)
require.NoError(t, err)
// the threshold for base roles is set in root
switch role {
case data.CanonicalRootRole:
require.False(t, bytes.Equal(origMeta, newMeta))
origRoot, newRoot := &data.SignedRoot{}, &data.SignedRoot{}
require.NoError(t, json.Unmarshal(origMeta, origRoot))
require.NoError(t, json.Unmarshal(newMeta, newRoot))
require.NotEqual(t, len(origRoot.Signed.Keys), len(newRoot.Signed.Keys))
for r, origRole := range origRoot.Signed.Roles {
newRole := newRoot.Signed.Roles[r]
require.Len(t, origRole.KeyIDs, 1)
require.Len(t, newRole.KeyIDs, 1)
if r == data.CanonicalRootRole {
require.NotEqual(t, origRole.KeyIDs[0], newRole.KeyIDs[0])
} else {
require.Equal(t, origRole.KeyIDs[0], newRole.KeyIDs[0])
}
}
rootRole, err := newRoot.BuildBaseRole(data.CanonicalRootRole)
require.NoError(t, err)
signedThing, err := newRoot.ToSigned()
require.NoError(t, err)
require.NoError(t, signed.VerifySignatures(signedThing, rootRole))
require.NoError(t, signed.VerifyVersion(&(newRoot.Signed.SignedCommon), 1))
default:
require.True(t, bytes.Equal(origMeta, newMeta), "bytes have changed for role %s", role)
}
}
}
func (rb *repoBuilder) loadDelegation(roleName string, content []byte, minVersion int, allowExpired bool) error {
delegationRole, err := rb.repo.GetDelegationRole(roleName)
if err != nil {
return err
}
// bytesToSigned checks checksum
signedObj, err := rb.bytesToSigned(content, roleName)
if err != nil {
return err
}
signedTargets, err := data.TargetsFromSigned(signedObj, roleName)
if err != nil {
return err
}
if err := signed.VerifyVersion(&(signedTargets.Signed.SignedCommon), minVersion); err != nil {
// don't capture in invalidRoles because the role we received is a rollback
return err
}
// verify signature
if err := signed.VerifySignatures(signedObj, delegationRole.BaseRole); err != nil {
rb.invalidRoles.Targets[roleName] = signedTargets
return err
}
if !allowExpired { // check must go at the end because all other validation should pass
if err := signed.VerifyExpiry(&(signedTargets.Signed.SignedCommon), roleName); err != nil {
rb.invalidRoles.Targets[roleName] = signedTargets
return err
}
}
signedTargets.Signatures = signedObj.Signatures
rb.repo.Targets[roleName] = signedTargets
return nil
}
/*
ValidateRoot receives a new root, validates its correctness and attempts to
do root key rotation if needed.
First we check if we have any trusted certificates for a particular GUN in
a previous root, if we have one. If the previous root is not nil and we find
certificates for this GUN, we've already seen this repository before, and
have a list of trusted certificates for it. In this case, we use this list of
certificates to attempt to validate this root file.
If the previous validation succeeds, we check the integrity of the root by
making sure that it is validated by itself. This means that we will attempt to
validate the root data with the certificates that are included in the root keys
themselves.
However, if we do not have any current trusted certificates for this GUN, we
check if there are any pinned certificates specified in the trust_pinning section
of the notary client config. If this section specifies a Certs section with this
GUN, we attempt to validate that the certificates present in the downloaded root
file match the pinned ID.
If the Certs section is empty for this GUN, we check if the trust_pinning
section specifies a CA section specified in the config for this GUN. If so, we check
that the specified CA is valid and has signed a certificate included in the downloaded
root file. The specified CA can be a prefix for this GUN.
If both the Certs and CA configs do not match this GUN, we fall back to the TOFU
section in the config: if true, we trust certificates specified in the root for
this GUN. If later we see a different certificate for that certificate, we return
an ErrValidationFailed error.
Note that since we only allow trust data to be downloaded over an HTTPS channel
we are using the current public PKI to validate the first download of the certificate
adding an extra layer of security over the normal (SSH style) trust model.
We shall call this: TOFUS.
Validation failure at any step will result in an ErrValidationFailed error.
*/
func ValidateRoot(prevRoot *data.SignedRoot, root *data.Signed, gun string, trustPinning TrustPinConfig) (*data.SignedRoot, error) {
logrus.Debugf("entered ValidateRoot with dns: %s", gun)
signedRoot, err := data.RootFromSigned(root)
if err != nil {
return nil, err
}
rootRole, err := signedRoot.BuildBaseRole(data.CanonicalRootRole)
if err != nil {
return nil, err
}
// Retrieve all the leaf and intermediate certificates in root for which the CN matches the GUN
allLeafCerts, allIntCerts := parseAllCerts(signedRoot)
certsFromRoot, err := validRootLeafCerts(allLeafCerts, gun, true)
validIntCerts := validRootIntCerts(allIntCerts)
if err != nil {
logrus.Debugf("error retrieving valid leaf certificates for: %s, %v", gun, err)
return nil, &ErrValidationFail{Reason: "unable to retrieve valid leaf certificates"}
}
logrus.Debugf("found %d leaf certs, of which %d are valid leaf certs for %s", len(allLeafCerts), len(certsFromRoot), gun)
// If we have a previous root, let's try to use it to validate that this new root is valid.
havePrevRoot := prevRoot != nil
if havePrevRoot {
// Retrieve all the trusted certificates from our previous root
// Note that we do not validate expiries here since our originally trusted root might have expired certs
allTrustedLeafCerts, allTrustedIntCerts := parseAllCerts(prevRoot)
trustedLeafCerts, err := validRootLeafCerts(allTrustedLeafCerts, gun, false)
if err != nil {
return nil, &ErrValidationFail{Reason: "could not retrieve trusted certs from previous root role data"}
}
// Use the certificates we found in the previous root for the GUN to verify its signatures
// This could potentially be an empty set, in which case we will fail to verify
logrus.Debugf("found %d valid root leaf certificates for %s: %s", len(trustedLeafCerts), gun,
prettyFormatCertIDs(trustedLeafCerts))
// Extract the previous root's threshold for signature verification
prevRootRoleData, ok := prevRoot.Signed.Roles[data.CanonicalRootRole]
if !ok {
return nil, &ErrValidationFail{Reason: "could not retrieve previous root role data"}
}
err = signed.VerifySignatures(
root, data.BaseRole{Keys: utils.CertsToKeys(trustedLeafCerts, allTrustedIntCerts), Threshold: prevRootRoleData.Threshold})
if err != nil {
logrus.Debugf("failed to verify TUF data for: %s, %v", gun, err)
return nil, &ErrRootRotationFail{Reason: "failed to validate data with current trusted certificates"}
}
// Clear the IsValid marks we could have received from VerifySignatures
for i := range root.Signatures {
root.Signatures[i].IsValid = false
}
}
// Regardless of having a previous root or not, confirm that the new root validates against the trust pinning
logrus.Debugf("checking root against trust_pinning config for %s", gun)
trustPinCheckFunc, err := NewTrustPinChecker(trustPinning, gun, !havePrevRoot)
if err != nil {
return nil, &ErrValidationFail{Reason: err.Error()}
}
validPinnedCerts := map[string]*x509.Certificate{}
for id, cert := range certsFromRoot {
logrus.Debugf("checking trust-pinning for cert: %s", id)
if ok := trustPinCheckFunc(cert, validIntCerts[id]); !ok {
logrus.Debugf("trust-pinning check failed for cert: %s", id)
continue
}
validPinnedCerts[id] = cert
}
if len(validPinnedCerts) == 0 {
return nil, &ErrValidationFail{Reason: "unable to match any certificates to trust_pinning config"}
}
certsFromRoot = validPinnedCerts
// Validate the integrity of the new root (does it have valid signatures)
// Note that certsFromRoot is guaranteed to be unchanged only if we had prior cert data for this GUN or enabled TOFUS
// If we attempted to pin a certain certificate or CA, certsFromRoot could have been pruned accordingly
err = signed.VerifySignatures(root, data.BaseRole{
Keys: utils.CertsToKeys(certsFromRoot, validIntCerts), Threshold: rootRole.Threshold})
if err != nil {
logrus.Debugf("failed to verify TUF data for: %s, %v", gun, err)
return nil, &ErrValidationFail{Reason: "failed to validate integrity of roots"}
}
logrus.Debugf("root validation succeeded for %s", gun)
// Call RootFromSigned to make sure we pick up on the IsValid markings from VerifySignatures
return data.RootFromSigned(root)
}
func verifyRootSignatureAgainstKey(t *testing.T, signedRoot *data.Signed, key data.PublicKey) error {
roleWithKeys := data.BaseRole{Name: data.CanonicalRootRole, Keys: data.Keys{key.ID(): key}, Threshold: 1}
return signed.VerifySignatures(signedRoot, roleWithKeys)
}
/*
ValidateRoot receives a new root, validates its correctness and attempts to
do root key rotation if needed.
First we list the current trusted certificates we have for a particular GUN. If
that list is non-empty means that we've already seen this repository before, and
have a list of trusted certificates for it. In this case, we use this list of
certificates to attempt to validate this root file.
If the previous validation succeeds, we check the integrity of the root by
making sure that it is validated by itself. This means that we will attempt to
validate the root data with the certificates that are included in the root keys
themselves.
However, if we do not have any current trusted certificates for this GUN, we
check if there are any pinned certificates specified in the trust_pinning section
of the notary client config. If this section specifies a Certs section with this
GUN, we attempt to validate that the certificates present in the downloaded root
file match the pinned ID.
If the Certs section is empty for this GUN, we check if the trust_pinning
section specifies a CA section specified in the config for this GUN. If so, we check
that the specified CA is valid and has signed a certificate included in the downloaded
root file. The specified CA can be a prefix for this GUN.
If both the Certs and CA configs do not match this GUN, we fall back to the TOFU
section in the config: if true, we trust certificates specified in the root for
this GUN. If later we see a different certificate for that certificate, we return
an ErrValidationFailed error.
Note that since we only allow trust data to be downloaded over an HTTPS channel
we are using the current public PKI to validate the first download of the certificate
adding an extra layer of security over the normal (SSH style) trust model.
We shall call this: TOFUS.
Validation failure at any step will result in an ErrValidationFailed error.
*/
func ValidateRoot(certStore trustmanager.X509Store, root *data.Signed, gun string, trustPinning TrustPinConfig) error {
logrus.Debugf("entered ValidateRoot with dns: %s", gun)
signedRoot, err := data.RootFromSigned(root)
if err != nil {
return err
}
rootRole, err := signedRoot.BuildBaseRole(data.CanonicalRootRole)
if err != nil {
return err
}
// Retrieve all the leaf and intermediate certificates in root for which the CN matches the GUN
allLeafCerts, allIntCerts := parseAllCerts(signedRoot)
certsFromRoot, err := validRootLeafCerts(allLeafCerts, gun)
if err != nil {
logrus.Debugf("error retrieving valid leaf certificates for: %s, %v", gun, err)
return &ErrValidationFail{Reason: "unable to retrieve valid leaf certificates"}
}
// Retrieve all the trusted certificates that match this gun
trustedCerts, err := certStore.GetCertificatesByCN(gun)
if err != nil {
// If the error that we get back is different than ErrNoCertificatesFound
// we couldn't check if there are any certificates with this CN already
// trusted. Let's take the conservative approach and return a failed validation
if _, ok := err.(*trustmanager.ErrNoCertificatesFound); !ok {
logrus.Debugf("error retrieving trusted certificates for: %s, %v", gun, err)
return &ErrValidationFail{Reason: "unable to retrieve trusted certificates"}
}
}
// If we have certificates that match this specific GUN, let's make sure to
// use them first to validate that this new root is valid.
if len(trustedCerts) != 0 {
logrus.Debugf("found %d valid root certificates for %s: %s", len(trustedCerts), gun,
prettyFormatCertIDs(trustedCerts))
err = signed.VerifySignatures(
root, data.BaseRole{Keys: trustmanager.CertsToKeys(trustedCerts, allIntCerts), Threshold: 1})
if err != nil {
logrus.Debugf("failed to verify TUF data for: %s, %v", gun, err)
return &ErrValidationFail{Reason: "failed to validate data with current trusted certificates"}
}
} else {
logrus.Debugf("found no currently valid root certificates for %s, using trust_pinning config to bootstrap trust", gun)
trustPinCheckFunc, err := NewTrustPinChecker(trustPinning, gun)
if err != nil {
return &ErrValidationFail{Reason: err.Error()}
}
validPinnedCerts := []*x509.Certificate{}
for _, cert := range certsFromRoot {
certID, err := trustmanager.FingerprintCert(cert)
if err != nil {
continue
}
if ok := trustPinCheckFunc(cert, allIntCerts[certID]); !ok {
continue
}
validPinnedCerts = append(validPinnedCerts, cert)
}
if len(validPinnedCerts) == 0 {
return &ErrValidationFail{Reason: "unable to match any certificates to trust_pinning config"}
}
certsFromRoot = validPinnedCerts
}
// Validate the integrity of the new root (does it have valid signatures)
// Note that certsFromRoot is guaranteed to be unchanged only if we had prior cert data for this GUN or enabled TOFUS
// If we attempted to pin a certain certificate or CA, certsFromRoot could have been pruned accordingly
err = signed.VerifySignatures(root, data.BaseRole{
Keys: trustmanager.CertsToKeys(certsFromRoot, allIntCerts), Threshold: rootRole.Threshold})
if err != nil {
logrus.Debugf("failed to verify TUF data for: %s, %v", gun, err)
return &ErrValidationFail{Reason: "failed to validate integrity of roots"}
}
// Getting here means:
// A) we had trusted certificates and both the old and new validated this root.
// or
// B) we had no trusted certificates but the new set of certificates has integrity (self-signed).
logrus.Debugf("entering root certificate rotation for: %s", gun)
// Do root certificate rotation: we trust only the certs present in the new root
// First we add all the new certificates (even if they already exist)
for _, cert := range certsFromRoot {
err := certStore.AddCert(cert)
if err != nil {
// If the error is already exists we don't fail the rotation
if _, ok := err.(*trustmanager.ErrCertExists); ok {
logrus.Debugf("ignoring certificate addition to: %s", gun)
continue
}
logrus.Debugf("error adding new trusted certificate for: %s, %v", gun, err)
}
}
// Now we delete old certificates that aren't present in the new root
oldCertsToRemove, err := certsToRemove(trustedCerts, certsFromRoot)
if err != nil {
logrus.Debugf("inconsistency when removing old certificates: %v", err)
return err
}
for certID, cert := range oldCertsToRemove {
logrus.Debugf("removing certificate with certID: %s", certID)
err = certStore.RemoveCert(cert)
if err != nil {
logrus.Debugf("failed to remove trusted certificate with keyID: %s, %v", certID, err)
return &ErrRootRotationFail{Reason: "failed to rotate root keys"}
}
}
logrus.Debugf("Root validation succeeded for %s", gun)
return nil
}