DockerCLI/vendor/github.com/docker/notary/tuf/tuf.go

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// Package tuf defines the core TUF logic around manipulating a repo.
package tuf
import (
"bytes"
"encoding/json"
"fmt"
"strings"
"time"
"github.com/Sirupsen/logrus"
"github.com/docker/notary"
"github.com/docker/notary/tuf/data"
"github.com/docker/notary/tuf/signed"
"github.com/docker/notary/tuf/utils"
)
// ErrSigVerifyFail - signature verification failed
type ErrSigVerifyFail struct{}
func (e ErrSigVerifyFail) Error() string {
return "Error: Signature verification failed"
}
// ErrMetaExpired - metadata file has expired
type ErrMetaExpired struct{}
func (e ErrMetaExpired) Error() string {
return "Error: Metadata has expired"
}
// ErrLocalRootExpired - the local root file is out of date
type ErrLocalRootExpired struct{}
func (e ErrLocalRootExpired) Error() string {
return "Error: Local Root Has Expired"
}
// ErrNotLoaded - attempted to access data that has not been loaded into
// the repo. This means specifically that the relevant JSON file has not
// been loaded.
type ErrNotLoaded struct {
Role data.RoleName
}
func (err ErrNotLoaded) Error() string {
return fmt.Sprintf("%s role has not been loaded", err.Role)
}
// StopWalk - used by visitor functions to signal WalkTargets to stop walking
type StopWalk struct{}
// Repo is an in memory representation of the TUF Repo.
// It operates at the data.Signed level, accepting and producing
// data.Signed objects. Users of a Repo are responsible for
// fetching raw JSON and using the Set* functions to populate
// the Repo instance.
type Repo struct {
Root *data.SignedRoot
Targets map[data.RoleName]*data.SignedTargets
Snapshot *data.SignedSnapshot
Timestamp *data.SignedTimestamp
cryptoService signed.CryptoService
// Because Repo is a mutable structure, these keep track of what the root
// role was when a root is set on the repo (as opposed to what it might be
// after things like AddBaseKeys and RemoveBaseKeys have been called on it).
// If we know what the original was, we'll if and how to handle root
// rotations.
originalRootRole data.BaseRole
}
// NewRepo initializes a Repo instance with a CryptoService.
// If the Repo will only be used for reading, the CryptoService
// can be nil.
func NewRepo(cryptoService signed.CryptoService) *Repo {
return &Repo{
Targets: make(map[data.RoleName]*data.SignedTargets),
cryptoService: cryptoService,
}
}
// AddBaseKeys is used to add keys to the role in root.json
func (tr *Repo) AddBaseKeys(role data.RoleName, keys ...data.PublicKey) error {
if tr.Root == nil {
return ErrNotLoaded{Role: data.CanonicalRootRole}
}
ids := []string{}
for _, k := range keys {
// Store only the public portion
tr.Root.Signed.Keys[k.ID()] = k
tr.Root.Signed.Roles[role].KeyIDs = append(tr.Root.Signed.Roles[role].KeyIDs, k.ID())
ids = append(ids, k.ID())
}
tr.Root.Dirty = true
// also, whichever role was switched out needs to be re-signed
// root has already been marked dirty.
switch role {
case data.CanonicalSnapshotRole:
if tr.Snapshot != nil {
tr.Snapshot.Dirty = true
}
case data.CanonicalTargetsRole:
if target, ok := tr.Targets[data.CanonicalTargetsRole]; ok {
target.Dirty = true
}
case data.CanonicalTimestampRole:
if tr.Timestamp != nil {
tr.Timestamp.Dirty = true
}
}
return nil
}
// ReplaceBaseKeys is used to replace all keys for the given role with the new keys
func (tr *Repo) ReplaceBaseKeys(role data.RoleName, keys ...data.PublicKey) error {
r, err := tr.GetBaseRole(role)
if err != nil {
return err
}
err = tr.RemoveBaseKeys(role, r.ListKeyIDs()...)
if err != nil {
return err
}
return tr.AddBaseKeys(role, keys...)
}
// RemoveBaseKeys is used to remove keys from the roles in root.json
func (tr *Repo) RemoveBaseKeys(role data.RoleName, keyIDs ...string) error {
if tr.Root == nil {
return ErrNotLoaded{Role: data.CanonicalRootRole}
}
var keep []string
toDelete := make(map[string]struct{})
emptyStruct := struct{}{}
// remove keys from specified role
for _, k := range keyIDs {
toDelete[k] = emptyStruct
}
oldKeyIDs := tr.Root.Signed.Roles[role].KeyIDs
for _, rk := range oldKeyIDs {
if _, ok := toDelete[rk]; !ok {
keep = append(keep, rk)
}
}
tr.Root.Signed.Roles[role].KeyIDs = keep
// also, whichever role had keys removed needs to be re-signed
// root has already been marked dirty.
tr.markRoleDirty(role)
// determine which keys are no longer in use by any roles
for roleName, r := range tr.Root.Signed.Roles {
if roleName == role {
continue
}
for _, rk := range r.KeyIDs {
if _, ok := toDelete[rk]; ok {
delete(toDelete, rk)
}
}
}
// Remove keys no longer in use by any roles, except for root keys.
// Root private keys must be kept in tr.cryptoService to be able to sign
// for rotation, and root certificates must be kept in tr.Root.SignedKeys
// because we are not necessarily storing them elsewhere (tuf.Repo does not
// depend on certs.Manager, that is an upper layer), and without storing
// the certificates in their x509 form we are not able to do the
// util.CanonicalKeyID conversion.
if role != data.CanonicalRootRole {
for k := range toDelete {
delete(tr.Root.Signed.Keys, k)
tr.cryptoService.RemoveKey(k)
}
}
tr.Root.Dirty = true
return nil
}
func (tr *Repo) markRoleDirty(role data.RoleName) {
switch role {
case data.CanonicalSnapshotRole:
if tr.Snapshot != nil {
tr.Snapshot.Dirty = true
}
case data.CanonicalTargetsRole:
if target, ok := tr.Targets[data.CanonicalTargetsRole]; ok {
target.Dirty = true
}
case data.CanonicalTimestampRole:
if tr.Timestamp != nil {
tr.Timestamp.Dirty = true
}
}
}
// GetBaseRole gets a base role from this repo's metadata
func (tr *Repo) GetBaseRole(name data.RoleName) (data.BaseRole, error) {
if !data.ValidRole(name) {
return data.BaseRole{}, data.ErrInvalidRole{Role: name, Reason: "invalid base role name"}
}
if tr.Root == nil {
return data.BaseRole{}, ErrNotLoaded{data.CanonicalRootRole}
}
// Find the role data public keys for the base role from TUF metadata
baseRole, err := tr.Root.BuildBaseRole(name)
if err != nil {
return data.BaseRole{}, err
}
return baseRole, nil
}
// GetDelegationRole gets a delegation role from this repo's metadata, walking from the targets role down to the delegation itself
func (tr *Repo) GetDelegationRole(name data.RoleName) (data.DelegationRole, error) {
if !data.IsDelegation(name) {
return data.DelegationRole{}, data.ErrInvalidRole{Role: name, Reason: "invalid delegation name"}
}
if tr.Root == nil {
return data.DelegationRole{}, ErrNotLoaded{data.CanonicalRootRole}
}
_, ok := tr.Root.Signed.Roles[data.CanonicalTargetsRole]
if !ok {
return data.DelegationRole{}, ErrNotLoaded{data.CanonicalTargetsRole}
}
// Traverse target metadata, down to delegation itself
// Get all public keys for the base role from TUF metadata
_, ok = tr.Targets[data.CanonicalTargetsRole]
if !ok {
return data.DelegationRole{}, ErrNotLoaded{data.CanonicalTargetsRole}
}
// Start with top level roles in targets. Walk the chain of ancestors
// until finding the desired role, or we run out of targets files to search.
var foundRole *data.DelegationRole
buildDelegationRoleVisitor := func(tgt *data.SignedTargets, validRole data.DelegationRole) interface{} {
// Try to find the delegation and build a DelegationRole structure
for _, role := range tgt.Signed.Delegations.Roles {
if role.Name == name {
delgRole, err := tgt.BuildDelegationRole(name)
if err != nil {
return err
}
// Check all public key certificates in the role for expiry
// Currently we do not reject expired delegation keys but warn if they might expire soon or have already
for keyID, pubKey := range delgRole.Keys {
certFromKey, err := utils.LoadCertFromPEM(pubKey.Public())
if err != nil {
continue
}
if err := utils.ValidateCertificate(certFromKey, true); err != nil {
if _, ok := err.(data.ErrCertExpired); !ok {
// do not allow other invalid cert errors
return err
}
logrus.Warnf("error with delegation %s key ID %d: %s", delgRole.Name, keyID, err)
}
}
foundRole = &delgRole
return StopWalk{}
}
}
return nil
}
// Walk to the parent of this delegation, since that is where its role metadata exists
err := tr.WalkTargets("", name.Parent(), buildDelegationRoleVisitor)
if err != nil {
return data.DelegationRole{}, err
}
// We never found the delegation. In the context of this repo it is considered
// invalid. N.B. it may be that it existed at one point but an ancestor has since
// been modified/removed.
if foundRole == nil {
return data.DelegationRole{}, data.ErrInvalidRole{Role: name, Reason: "delegation does not exist"}
}
return *foundRole, nil
}
// GetAllLoadedRoles returns a list of all role entries loaded in this TUF repo, could be empty
func (tr *Repo) GetAllLoadedRoles() []*data.Role {
var res []*data.Role
if tr.Root == nil {
// if root isn't loaded, we should consider we have no loaded roles because we can't
// trust any other state that might be present
return res
}
for name, rr := range tr.Root.Signed.Roles {
res = append(res, &data.Role{
RootRole: *rr,
Name: name,
})
}
for _, delegate := range tr.Targets {
for _, r := range delegate.Signed.Delegations.Roles {
res = append(res, r)
}
}
return res
}
// Walk to parent, and either create or update this delegation. We can only create a new delegation if we're given keys
// Ensure all updates are valid, by checking against parent ancestor paths and ensuring the keys meet the role threshold.
func delegationUpdateVisitor(roleName data.RoleName, addKeys data.KeyList, removeKeys, addPaths, removePaths []string, clearAllPaths bool, newThreshold int) walkVisitorFunc {
return func(tgt *data.SignedTargets, validRole data.DelegationRole) interface{} {
var err error
// Validate the changes underneath this restricted validRole for adding paths, reject invalid path additions
if len(addPaths) != len(data.RestrictDelegationPathPrefixes(validRole.Paths, addPaths)) {
return data.ErrInvalidRole{Role: roleName, Reason: "invalid paths to add to role"}
}
// Try to find the delegation and amend it using our changelist
var delgRole *data.Role
for _, role := range tgt.Signed.Delegations.Roles {
if role.Name == roleName {
// Make a copy and operate on this role until we validate the changes
keyIDCopy := make([]string, len(role.KeyIDs))
copy(keyIDCopy, role.KeyIDs)
pathsCopy := make([]string, len(role.Paths))
copy(pathsCopy, role.Paths)
delgRole = &data.Role{
RootRole: data.RootRole{
KeyIDs: keyIDCopy,
Threshold: role.Threshold,
},
Name: role.Name,
Paths: pathsCopy,
}
delgRole.RemovePaths(removePaths)
if clearAllPaths {
delgRole.Paths = []string{}
}
delgRole.AddPaths(addPaths)
delgRole.RemoveKeys(removeKeys)
break
}
}
// We didn't find the role earlier, so create it.
if addKeys == nil {
addKeys = data.KeyList{} // initialize to empty list if necessary so calling .IDs() below won't panic
}
if delgRole == nil {
delgRole, err = data.NewRole(roleName, newThreshold, addKeys.IDs(), addPaths)
if err != nil {
return err
}
}
// Add the key IDs to the role and the keys themselves to the parent
for _, k := range addKeys {
if !utils.StrSliceContains(delgRole.KeyIDs, k.ID()) {
delgRole.KeyIDs = append(delgRole.KeyIDs, k.ID())
}
}
// Make sure we have a valid role still
if len(delgRole.KeyIDs) < delgRole.Threshold {
logrus.Warnf("role %s has fewer keys than its threshold of %d; it will not be usable until keys are added to it", delgRole.Name, delgRole.Threshold)
}
// NOTE: this closure CANNOT error after this point, as we've committed to editing the SignedTargets metadata in the repo object.
// Any errors related to updating this delegation must occur before this point.
// If all of our changes were valid, we should edit the actual SignedTargets to match our copy
for _, k := range addKeys {
tgt.Signed.Delegations.Keys[k.ID()] = k
}
foundAt := utils.FindRoleIndex(tgt.Signed.Delegations.Roles, delgRole.Name)
if foundAt < 0 {
tgt.Signed.Delegations.Roles = append(tgt.Signed.Delegations.Roles, delgRole)
} else {
tgt.Signed.Delegations.Roles[foundAt] = delgRole
}
tgt.Dirty = true
utils.RemoveUnusedKeys(tgt)
return StopWalk{}
}
}
// UpdateDelegationKeys updates the appropriate delegations, either adding
// a new delegation or updating an existing one. If keys are
// provided, the IDs will be added to the role (if they do not exist
// there already), and the keys will be added to the targets file.
func (tr *Repo) UpdateDelegationKeys(roleName data.RoleName, addKeys data.KeyList, removeKeys []string, newThreshold int) error {
if !data.IsDelegation(roleName) {
return data.ErrInvalidRole{Role: roleName, Reason: "not a valid delegated role"}
}
parent := roleName.Parent()
if err := tr.VerifyCanSign(parent); err != nil {
return err
}
// check the parent role's metadata
_, ok := tr.Targets[parent]
if !ok { // the parent targetfile may not exist yet - if not, then create it
var err error
_, err = tr.InitTargets(parent)
if err != nil {
return err
}
}
// Walk to the parent of this delegation, since that is where its role metadata exists
// We do not have to verify that the walker reached its desired role in this scenario
// since we've already done another walk to the parent role in VerifyCanSign, and potentially made a targets file
return tr.WalkTargets("", roleName.Parent(), delegationUpdateVisitor(roleName, addKeys, removeKeys, []string{}, []string{}, false, newThreshold))
}
// PurgeDelegationKeys removes the provided canonical key IDs from all delegations
// present in the subtree rooted at role. The role argument must be provided in a wildcard
// format, i.e. targets/* would remove the key from all delegations in the repo
func (tr *Repo) PurgeDelegationKeys(role data.RoleName, removeKeys []string) error {
if !data.IsWildDelegation(role) {
return data.ErrInvalidRole{
Role: role,
Reason: "only wildcard roles can be used in a purge",
}
}
removeIDs := make(map[string]struct{})
for _, id := range removeKeys {
removeIDs[id] = struct{}{}
}
start := role.Parent()
tufIDToCanon := make(map[string]string)
purgeKeys := func(tgt *data.SignedTargets, validRole data.DelegationRole) interface{} {
var (
deleteCandidates []string
err error
)
for id, key := range tgt.Signed.Delegations.Keys {
var (
canonID string
ok bool
)
if canonID, ok = tufIDToCanon[id]; !ok {
canonID, err = utils.CanonicalKeyID(key)
if err != nil {
return err
}
tufIDToCanon[id] = canonID
}
if _, ok := removeIDs[canonID]; ok {
deleteCandidates = append(deleteCandidates, id)
}
}
if len(deleteCandidates) == 0 {
// none of the interesting keys were present. We're done with this role
return nil
}
// now we know there are changes, check if we'll be able to sign them in
if err := tr.VerifyCanSign(validRole.Name); err != nil {
logrus.Warnf(
"role %s contains keys being purged but you do not have the necessary keys present to sign it; keys will not be purged from %s or its immediate children",
validRole.Name,
validRole.Name,
)
return nil
}
// we know we can sign in the changes, delete the keys
for _, id := range deleteCandidates {
delete(tgt.Signed.Delegations.Keys, id)
}
// delete candidate keys from all roles.
for _, role := range tgt.Signed.Delegations.Roles {
role.RemoveKeys(deleteCandidates)
if len(role.KeyIDs) < role.Threshold {
logrus.Warnf("role %s has fewer keys than its threshold of %d; it will not be usable until keys are added to it", role.Name, role.Threshold)
}
}
tgt.Dirty = true
return nil
}
return tr.WalkTargets("", start, purgeKeys)
}
// UpdateDelegationPaths updates the appropriate delegation's paths.
// It is not allowed to create a new delegation.
func (tr *Repo) UpdateDelegationPaths(roleName data.RoleName, addPaths, removePaths []string, clearPaths bool) error {
if !data.IsDelegation(roleName) {
return data.ErrInvalidRole{Role: roleName, Reason: "not a valid delegated role"}
}
parent := roleName.Parent()
if err := tr.VerifyCanSign(parent); err != nil {
return err
}
// check the parent role's metadata
_, ok := tr.Targets[parent]
if !ok { // the parent targetfile may not exist yet
// if not, this is an error because a delegation must exist to edit only paths
return data.ErrInvalidRole{Role: roleName, Reason: "no valid delegated role exists"}
}
// Walk to the parent of this delegation, since that is where its role metadata exists
// We do not have to verify that the walker reached its desired role in this scenario
// since we've already done another walk to the parent role in VerifyCanSign
err := tr.WalkTargets("", parent, delegationUpdateVisitor(roleName, data.KeyList{}, []string{}, addPaths, removePaths, clearPaths, notary.MinThreshold))
if err != nil {
return err
}
return nil
}
// DeleteDelegation removes a delegated targets role from its parent
// targets object. It also deletes the delegation from the snapshot.
// DeleteDelegation will only make use of the role Name field.
func (tr *Repo) DeleteDelegation(roleName data.RoleName) error {
if !data.IsDelegation(roleName) {
return data.ErrInvalidRole{Role: roleName, Reason: "not a valid delegated role"}
}
parent := roleName.Parent()
if err := tr.VerifyCanSign(parent); err != nil {
return err
}
// delete delegated data from Targets map and Snapshot - if they don't
// exist, these are no-op
delete(tr.Targets, roleName)
tr.Snapshot.DeleteMeta(roleName)
p, ok := tr.Targets[parent]
if !ok {
// if there is no parent metadata (the role exists though), then this
// is as good as done.
return nil
}
foundAt := utils.FindRoleIndex(p.Signed.Delegations.Roles, roleName)
if foundAt >= 0 {
var roles []*data.Role
// slice out deleted role
roles = append(roles, p.Signed.Delegations.Roles[:foundAt]...)
if foundAt+1 < len(p.Signed.Delegations.Roles) {
roles = append(roles, p.Signed.Delegations.Roles[foundAt+1:]...)
}
p.Signed.Delegations.Roles = roles
utils.RemoveUnusedKeys(p)
p.Dirty = true
} // if the role wasn't found, it's a good as deleted
return nil
}
// InitRoot initializes an empty root file with the 4 core roles passed to the
// method, and the consistent flag.
func (tr *Repo) InitRoot(root, timestamp, snapshot, targets data.BaseRole, consistent bool) error {
rootRoles := make(map[data.RoleName]*data.RootRole)
rootKeys := make(map[string]data.PublicKey)
for _, r := range []data.BaseRole{root, timestamp, snapshot, targets} {
rootRoles[r.Name] = &data.RootRole{
Threshold: r.Threshold,
KeyIDs: r.ListKeyIDs(),
}
for kid, k := range r.Keys {
rootKeys[kid] = k
}
}
r, err := data.NewRoot(rootKeys, rootRoles, consistent)
if err != nil {
return err
}
tr.Root = r
tr.originalRootRole = root
return nil
}
// InitTargets initializes an empty targets, and returns the new empty target
func (tr *Repo) InitTargets(role data.RoleName) (*data.SignedTargets, error) {
if !data.IsDelegation(role) && role != data.CanonicalTargetsRole {
return nil, data.ErrInvalidRole{
Role: role,
Reason: fmt.Sprintf("role is not a valid targets role name: %s", role.String()),
}
}
targets := data.NewTargets()
tr.Targets[role] = targets
return targets, nil
}
// InitSnapshot initializes a snapshot based on the current root and targets
func (tr *Repo) InitSnapshot() error {
if tr.Root == nil {
return ErrNotLoaded{Role: data.CanonicalRootRole}
}
root, err := tr.Root.ToSigned()
if err != nil {
return err
}
if _, ok := tr.Targets[data.CanonicalTargetsRole]; !ok {
return ErrNotLoaded{Role: data.CanonicalTargetsRole}
}
targets, err := tr.Targets[data.CanonicalTargetsRole].ToSigned()
if err != nil {
return err
}
snapshot, err := data.NewSnapshot(root, targets)
if err != nil {
return err
}
tr.Snapshot = snapshot
return nil
}
// InitTimestamp initializes a timestamp based on the current snapshot
func (tr *Repo) InitTimestamp() error {
snap, err := tr.Snapshot.ToSigned()
if err != nil {
return err
}
timestamp, err := data.NewTimestamp(snap)
if err != nil {
return err
}
tr.Timestamp = timestamp
return nil
}
// TargetMeta returns the FileMeta entry for the given path in the
// targets file associated with the given role. This may be nil if
// the target isn't found in the targets file.
func (tr Repo) TargetMeta(role data.RoleName, path string) *data.FileMeta {
if t, ok := tr.Targets[role]; ok {
if m, ok := t.Signed.Targets[path]; ok {
return &m
}
}
return nil
}
// TargetDelegations returns a slice of Roles that are valid publishers
// for the target path provided.
func (tr Repo) TargetDelegations(role data.RoleName, path string) []*data.Role {
var roles []*data.Role
if t, ok := tr.Targets[role]; ok {
for _, r := range t.Signed.Delegations.Roles {
if r.CheckPaths(path) {
roles = append(roles, r)
}
}
}
return roles
}
// VerifyCanSign returns nil if the role exists and we have at least one
// signing key for the role, false otherwise. This does not check that we have
// enough signing keys to meet the threshold, since we want to support the use
// case of multiple signers for a role. It returns an error if the role doesn't
// exist or if there are no signing keys.
func (tr *Repo) VerifyCanSign(roleName data.RoleName) error {
var (
role data.BaseRole
err error
canonicalKeyIDs []string
)
// we only need the BaseRole part of a delegation because we're just
// checking KeyIDs
if data.IsDelegation(roleName) {
r, err := tr.GetDelegationRole(roleName)
if err != nil {
return err
}
role = r.BaseRole
} else {
role, err = tr.GetBaseRole(roleName)
}
if err != nil {
return data.ErrInvalidRole{Role: roleName, Reason: "does not exist"}
}
for keyID, k := range role.Keys {
check := []string{keyID}
if canonicalID, err := utils.CanonicalKeyID(k); err == nil {
check = append(check, canonicalID)
canonicalKeyIDs = append(canonicalKeyIDs, canonicalID)
}
for _, id := range check {
p, _, err := tr.cryptoService.GetPrivateKey(id)
if err == nil && p != nil {
return nil
}
}
}
return signed.ErrNoKeys{KeyIDs: canonicalKeyIDs}
}
// used for walking the targets/delegations tree, potentially modifying the underlying SignedTargets for the repo
type walkVisitorFunc func(*data.SignedTargets, data.DelegationRole) interface{}
// WalkTargets will apply the specified visitor function to iteratively walk the targets/delegation metadata tree,
// until receiving a StopWalk. The walk starts from the base "targets" role, and searches for the correct targetPath and/or rolePath
// to call the visitor function on. Any roles passed into skipRoles will be excluded from the walk, as well as roles in those subtrees
func (tr *Repo) WalkTargets(targetPath string, rolePath data.RoleName, visitTargets walkVisitorFunc, skipRoles ...data.RoleName) error {
// Start with the base targets role, which implicitly has the "" targets path
targetsRole, err := tr.GetBaseRole(data.CanonicalTargetsRole)
if err != nil {
return err
}
// Make the targets role have the empty path, when we treat it as a delegation role
roles := []data.DelegationRole{
{
BaseRole: targetsRole,
Paths: []string{""},
},
}
for len(roles) > 0 {
role := roles[0]
roles = roles[1:]
// Check the role metadata
signedTgt, ok := tr.Targets[role.Name]
if !ok {
// The role meta doesn't exist in the repo so continue onward
continue
}
// We're at a prefix of the desired role subtree, so add its delegation role children and continue walking
if strings.HasPrefix(rolePath.String(), role.Name.String()+"/") {
roles = append(roles, signedTgt.GetValidDelegations(role)...)
continue
}
// Determine whether to visit this role or not:
// If the paths validate against the specified targetPath and the role is empty or is a path in the subtree.
// Also check if we are choosing to skip visiting this role on this walk (see ListTargets and GetTargetByName priority)
if isValidPath(targetPath, role) && isAncestorRole(role.Name, rolePath) && !utils.RoleNameSliceContains(skipRoles, role.Name) {
// If we had matching path or role name, visit this target and determine whether or not to keep walking
res := visitTargets(signedTgt, role)
switch typedRes := res.(type) {
case StopWalk:
// If the visitor function signalled a stop, return nil to finish the walk
return nil
case nil:
// If the visitor function signalled to continue, add this role's delegation to the walk
roles = append(roles, signedTgt.GetValidDelegations(role)...)
case error:
// Propagate any errors from the visitor
return typedRes
default:
// Return out with an error if we got a different result
return fmt.Errorf("unexpected return while walking: %v", res)
}
}
}
return nil
}
// helper function that returns whether the candidateChild role name is an ancestor or equal to the candidateAncestor role name
// Will return true if given an empty candidateAncestor role name
// The HasPrefix check is for determining whether the role name for candidateChild is a child (direct or further down the chain)
// of candidateAncestor, for ex: candidateAncestor targets/a and candidateChild targets/a/b/c
func isAncestorRole(candidateChild data.RoleName, candidateAncestor data.RoleName) bool {
return candidateAncestor.String() == "" || candidateAncestor == candidateChild || strings.HasPrefix(candidateChild.String(), candidateAncestor.String()+"/")
}
// helper function that returns whether the delegation Role is valid against the given path
// Will return true if given an empty candidatePath
func isValidPath(candidatePath string, delgRole data.DelegationRole) bool {
return candidatePath == "" || delgRole.CheckPaths(candidatePath)
}
// AddTargets will attempt to add the given targets specifically to
// the directed role. If the metadata for the role doesn't exist yet,
// AddTargets will create one.
func (tr *Repo) AddTargets(role data.RoleName, targets data.Files) (data.Files, error) {
cantSignErr := tr.VerifyCanSign(role)
if _, ok := cantSignErr.(data.ErrInvalidRole); ok {
return nil, cantSignErr
}
var needSign bool
// check existence of the role's metadata
_, ok := tr.Targets[role]
if !ok { // the targetfile may not exist yet - if not, then create it
var err error
_, err = tr.InitTargets(role)
if err != nil {
return nil, err
}
}
addedTargets := make(data.Files)
addTargetVisitor := func(targetPath string, targetMeta data.FileMeta) func(*data.SignedTargets, data.DelegationRole) interface{} {
return func(tgt *data.SignedTargets, validRole data.DelegationRole) interface{} {
// We've already validated the role's target path in our walk, so just modify the metadata
if targetMeta.Equals(tgt.Signed.Targets[targetPath]) {
// Also add to our new addedTargets map because this target was "added" successfully
addedTargets[targetPath] = targetMeta
return StopWalk{}
}
needSign = true
if cantSignErr == nil {
tgt.Signed.Targets[targetPath] = targetMeta
tgt.Dirty = true
// Also add to our new addedTargets map to keep track of every target we've added successfully
addedTargets[targetPath] = targetMeta
}
return StopWalk{}
}
}
// Walk the role tree while validating the target paths, and add all of our targets
for path, target := range targets {
tr.WalkTargets(path, role, addTargetVisitor(path, target))
if needSign && cantSignErr != nil {
return nil, cantSignErr
}
}
if len(addedTargets) != len(targets) {
return nil, fmt.Errorf("Could not add all targets")
}
return nil, nil
}
// RemoveTargets removes the given target (paths) from the given target role (delegation)
func (tr *Repo) RemoveTargets(role data.RoleName, targets ...string) error {
cantSignErr := tr.VerifyCanSign(role)
if _, ok := cantSignErr.(data.ErrInvalidRole); ok {
return cantSignErr
}
var needSign bool
removeTargetVisitor := func(targetPath string) func(*data.SignedTargets, data.DelegationRole) interface{} {
return func(tgt *data.SignedTargets, validRole data.DelegationRole) interface{} {
// We've already validated the role path in our walk, so just modify the metadata
// We don't check against the target path against the valid role paths because it's
// possible we got into an invalid state and are trying to fix it
if _, needSign = tgt.Signed.Targets[targetPath]; needSign && cantSignErr == nil {
delete(tgt.Signed.Targets, targetPath)
tgt.Dirty = true
}
return StopWalk{}
}
}
// if the role exists but metadata does not yet, then our work is done
_, ok := tr.Targets[role]
if ok {
for _, path := range targets {
tr.WalkTargets("", role, removeTargetVisitor(path))
if needSign && cantSignErr != nil {
return cantSignErr
}
}
}
return nil
}
// UpdateSnapshot updates the FileMeta for the given role based on the Signed object
func (tr *Repo) UpdateSnapshot(role data.RoleName, s *data.Signed) error {
jsonData, err := json.Marshal(s)
if err != nil {
return err
}
meta, err := data.NewFileMeta(bytes.NewReader(jsonData), data.NotaryDefaultHashes...)
if err != nil {
return err
}
tr.Snapshot.Signed.Meta[role.String()] = meta
tr.Snapshot.Dirty = true
return nil
}
// UpdateTimestamp updates the snapshot meta in the timestamp based on the Signed object
func (tr *Repo) UpdateTimestamp(s *data.Signed) error {
jsonData, err := json.Marshal(s)
if err != nil {
return err
}
meta, err := data.NewFileMeta(bytes.NewReader(jsonData), data.NotaryDefaultHashes...)
if err != nil {
return err
}
tr.Timestamp.Signed.Meta[data.CanonicalSnapshotRole.String()] = meta
tr.Timestamp.Dirty = true
return nil
}
// SignRoot signs the root, using all keys from the "root" role (i.e. currently trusted)
// as well as available keys used to sign the previous version, if the public part is
// carried in tr.Root.Keys and the private key is available (i.e. probably previously
// trusted keys, to allow rollover). If there are any errors, attempt to put root
// back to the way it was (so version won't be incremented, for instance).
// Extra signing keys can be added to support older clients
func (tr *Repo) SignRoot(expires time.Time, extraSigningKeys data.KeyList) (*data.Signed, error) {
logrus.Debug("signing root...")
// duplicate root and attempt to modify it rather than the existing root
rootBytes, err := tr.Root.MarshalJSON()
if err != nil {
return nil, err
}
tempRoot := data.SignedRoot{}
if err := json.Unmarshal(rootBytes, &tempRoot); err != nil {
return nil, err
}
currRoot, err := tr.GetBaseRole(data.CanonicalRootRole)
if err != nil {
return nil, err
}
var rolesToSignWith []data.BaseRole
// If the root role (root keys or root threshold) has changed, sign with the
// previous root role keys
if !tr.originalRootRole.Equals(currRoot) {
rolesToSignWith = append(rolesToSignWith, tr.originalRootRole)
}
tempRoot.Signed.Expires = expires
tempRoot.Signed.Version++
rolesToSignWith = append(rolesToSignWith, currRoot)
signed, err := tempRoot.ToSigned()
if err != nil {
return nil, err
}
signed, err = tr.sign(signed, rolesToSignWith, extraSigningKeys)
if err != nil {
return nil, err
}
tr.Root = &tempRoot
tr.Root.Signatures = signed.Signatures
tr.originalRootRole = currRoot
return signed, nil
}
func oldRootVersionName(version int) string {
return fmt.Sprintf("%s.%v", data.CanonicalRootRole, version)
}
// SignTargets signs the targets file for the given top level or delegated targets role
func (tr *Repo) SignTargets(role data.RoleName, expires time.Time) (*data.Signed, error) {
logrus.Debugf("sign targets called for role %s", role)
if _, ok := tr.Targets[role]; !ok {
return nil, data.ErrInvalidRole{
Role: role,
Reason: "SignTargets called with non-existent targets role",
}
}
tr.Targets[role].Signed.Expires = expires
tr.Targets[role].Signed.Version++
signed, err := tr.Targets[role].ToSigned()
if err != nil {
logrus.Debug("errored getting targets data.Signed object")
return nil, err
}
var targets data.BaseRole
if role == data.CanonicalTargetsRole {
targets, err = tr.GetBaseRole(role)
} else {
tr, err := tr.GetDelegationRole(role)
if err != nil {
return nil, err
}
targets = tr.BaseRole
}
if err != nil {
return nil, err
}
signed, err = tr.sign(signed, []data.BaseRole{targets}, nil)
if err != nil {
logrus.Debug("errored signing ", role)
return nil, err
}
tr.Targets[role].Signatures = signed.Signatures
return signed, nil
}
// SignSnapshot updates the snapshot based on the current targets and root then signs it
func (tr *Repo) SignSnapshot(expires time.Time) (*data.Signed, error) {
logrus.Debug("signing snapshot...")
signedRoot, err := tr.Root.ToSigned()
if err != nil {
return nil, err
}
err = tr.UpdateSnapshot(data.CanonicalRootRole, signedRoot)
if err != nil {
return nil, err
}
tr.Root.Dirty = false // root dirty until changes captures in snapshot
for role, targets := range tr.Targets {
signedTargets, err := targets.ToSigned()
if err != nil {
return nil, err
}
err = tr.UpdateSnapshot(role, signedTargets)
if err != nil {
return nil, err
}
targets.Dirty = false
}
tr.Snapshot.Signed.Expires = expires
tr.Snapshot.Signed.Version++
signed, err := tr.Snapshot.ToSigned()
if err != nil {
return nil, err
}
snapshot, err := tr.GetBaseRole(data.CanonicalSnapshotRole)
if err != nil {
return nil, err
}
signed, err = tr.sign(signed, []data.BaseRole{snapshot}, nil)
if err != nil {
return nil, err
}
tr.Snapshot.Signatures = signed.Signatures
return signed, nil
}
// SignTimestamp updates the timestamp based on the current snapshot then signs it
func (tr *Repo) SignTimestamp(expires time.Time) (*data.Signed, error) {
logrus.Debug("SignTimestamp")
signedSnapshot, err := tr.Snapshot.ToSigned()
if err != nil {
return nil, err
}
err = tr.UpdateTimestamp(signedSnapshot)
if err != nil {
return nil, err
}
tr.Timestamp.Signed.Expires = expires
tr.Timestamp.Signed.Version++
signed, err := tr.Timestamp.ToSigned()
if err != nil {
return nil, err
}
timestamp, err := tr.GetBaseRole(data.CanonicalTimestampRole)
if err != nil {
return nil, err
}
signed, err = tr.sign(signed, []data.BaseRole{timestamp}, nil)
if err != nil {
return nil, err
}
tr.Timestamp.Signatures = signed.Signatures
tr.Snapshot.Dirty = false // snapshot is dirty until changes have been captured in timestamp
return signed, nil
}
func (tr Repo) sign(signedData *data.Signed, roles []data.BaseRole, optionalKeys []data.PublicKey) (*data.Signed, error) {
validKeys := optionalKeys
for _, r := range roles {
roleKeys := r.ListKeys()
validKeys = append(roleKeys, validKeys...)
if err := signed.Sign(tr.cryptoService, signedData, roleKeys, r.Threshold, validKeys); err != nil {
return nil, err
}
}
// Attempt to sign with the optional keys, but ignore any errors, because these keys are optional
signed.Sign(tr.cryptoService, signedData, optionalKeys, 0, validKeys)
return signedData, nil
}