// 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{}
}
}
