// GetDelegation finds the role entry representing the provided
// role name or ErrInvalidRole
func (tr *Repo) GetDelegation(role string) (*data.Role, error) {
r := data.Role{Name: role}
if !r.IsDelegation() {
return nil, data.ErrInvalidRole{Role: role, Reason: "not a valid delegated role"}
}
parent := path.Dir(role)
// check the parent role
if parentRole := tr.keysDB.GetRole(parent); parentRole == nil {
return nil, data.ErrInvalidRole{Role: role, Reason: "parent role not found"}
}
// check the parent role's metadata
p, ok := tr.Targets[parent]
if !ok { // the parent targetfile may not exist yet, so it can't be in the list
return nil, data.ErrNoSuchRole{Role: role}
}
foundAt := utils.FindRoleIndex(p.Signed.Delegations.Roles, role)
if foundAt < 0 {
return nil, data.ErrNoSuchRole{Role: role}
}
return p.Signed.Delegations.Roles[foundAt], nil
}
// UpdateDelegations 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) UpdateDelegations(role *data.Role, keys []data.PublicKey) error {
if !role.IsDelegation() || !role.IsValid() {
return data.ErrInvalidRole{Role: role.Name, Reason: "not a valid delegated role"}
}
parent := path.Dir(role.Name)
if err := tr.VerifyCanSign(parent); err != nil {
return err
}
// check the parent role's metadata
p, ok := tr.Targets[parent]
if !ok { // the parent targetfile may not exist yet - if not, then create it
var err error
p, err = tr.InitTargets(parent)
if err != nil {
return err
}
}
for _, k := range keys {
if !utils.StrSliceContains(role.KeyIDs, k.ID()) {
role.KeyIDs = append(role.KeyIDs, k.ID())
}
p.Signed.Delegations.Keys[k.ID()] = k
tr.keysDB.AddKey(k)
}
// if the role has fewer keys than the threshold, it
// will never be able to create a valid targets file
// and should be considered invalid.
if len(role.KeyIDs) < role.Threshold {
return data.ErrInvalidRole{Role: role.Name, Reason: "insufficient keys to meet threshold"}
}
foundAt := utils.FindRoleIndex(p.Signed.Delegations.Roles, role.Name)
if foundAt >= 0 {
p.Signed.Delegations.Roles[foundAt] = role
} else {
p.Signed.Delegations.Roles = append(p.Signed.Delegations.Roles, role)
}
// We've made a change to parent. Set it to dirty
p.Dirty = true
// We don't actually want to create the new delegation metadata yet.
// When we add a delegation, it may only be signable by a key we don't have
// (hence we are delegating signing).
tr.keysDB.AddRole(role)
utils.RemoveUnusedKeys(p)
return nil
}
// InitTargets initializes an empty targets, and returns the new empty target
func (tr *Repo) InitTargets(role string) (*data.SignedTargets, error) {
r := data.Role{Name: role}
if !r.IsDelegation() && role != data.CanonicalTargetsRole {
return nil, data.ErrInvalidRole{
Role: role,
Reason: fmt.Sprintf("role is not a valid targets role name: %s", role),
}
}
targets := data.NewTargets()
tr.Targets[role] = targets
return targets, 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(role data.Role) error {
if !role.IsDelegation() {
return data.ErrInvalidRole{Role: role.Name, Reason: "not a valid delegated role"}
}
// the role variable must not be used past this assignment for safety
name := role.Name
parent := path.Dir(name)
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, name)
tr.Snapshot.DeleteMeta(name)
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, name)
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
}
// UpdateDelegations 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.
// The "before" argument specifies another role which this new role
// will be added in front of (i.e. higher priority) in the delegation list.
// An empty before string indicates to add the role to the end of the
// delegation list.
// A new, empty, targets file will be created for the new role.
func (tr *Repo) UpdateDelegations(role *data.Role, keys []data.PublicKey, before string) error {
if !role.IsDelegation() || !role.IsValid() {
return data.ErrInvalidRole{Role: role.Name}
}
parent := filepath.Dir(role.Name)
p, ok := tr.Targets[parent]
if !ok {
return data.ErrInvalidRole{Role: role.Name}
}
for _, k := range keys {
if !utils.StrSliceContains(role.KeyIDs, k.ID()) {
role.KeyIDs = append(role.KeyIDs, k.ID())
}
p.Signed.Delegations.Keys[k.ID()] = k
tr.keysDB.AddKey(k)
}
i := -1
var r *data.Role
for i, r = range p.Signed.Delegations.Roles {
if r.Name == role.Name {
break
}
}
if i >= 0 {
p.Signed.Delegations.Roles[i] = role
} else {
p.Signed.Delegations.Roles = append(p.Signed.Delegations.Roles, role)
}
p.Dirty = true
roleTargets := data.NewTargets() // NewTargets always marked Dirty
tr.Targets[role.Name] = roleTargets
tr.keysDB.AddRole(role)
return nil
}
// 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 string, 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 only if we have keys to add
if delgRole == nil {
if len(addKeys) > 0 {
delgRole, err = data.NewRole(roleName, newThreshold, addKeys.IDs(), addPaths)
if err != nil {
return err
}
} else {
// If we can't find the role and didn't specify keys to add, this is an error
return data.ErrInvalidRole{Role: roleName, Reason: "cannot create new delegation without keys"}
}
}
// 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 {
return data.ErrInvalidRole{Role: roleName, Reason: "insufficient keys to meet 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{}
}
}