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

172 lines
4.8 KiB
Go

package data
import (
"fmt"
"github.com/docker/go/canonical/json"
)
// SignedRoot is a fully unpacked root.json
type SignedRoot struct {
Signatures []Signature
Signed Root
Dirty bool
}
// Root is the Signed component of a root.json
type Root struct {
SignedCommon
Keys Keys `json:"keys"`
Roles map[string]*RootRole `json:"roles"`
ConsistentSnapshot bool `json:"consistent_snapshot"`
}
// isValidRootStructure returns an error, or nil, depending on whether the content of the struct
// is valid for root metadata. This does not check signatures or expiry, just that
// the metadata content is valid.
func isValidRootStructure(r Root) error {
expectedType := TUFTypes[CanonicalRootRole]
if r.Type != expectedType {
return ErrInvalidMetadata{
role: CanonicalRootRole, msg: fmt.Sprintf("expected type %s, not %s", expectedType, r.Type)}
}
if r.Version < 1 {
return ErrInvalidMetadata{
role: CanonicalRootRole, msg: "version cannot be less than 1"}
}
// all the base roles MUST appear in the root.json - other roles are allowed,
// but other than the mirror role (not currently supported) are out of spec
for _, roleName := range BaseRoles {
roleObj, ok := r.Roles[roleName]
if !ok || roleObj == nil {
return ErrInvalidMetadata{
role: CanonicalRootRole, msg: fmt.Sprintf("missing %s role specification", roleName)}
}
if err := isValidRootRoleStructure(CanonicalRootRole, roleName, *roleObj, r.Keys); err != nil {
return err
}
}
return nil
}
func isValidRootRoleStructure(metaContainingRole, rootRoleName string, r RootRole, validKeys Keys) error {
if r.Threshold < 1 {
return ErrInvalidMetadata{
role: metaContainingRole,
msg: fmt.Sprintf("invalid threshold specified for %s: %v ", rootRoleName, r.Threshold),
}
}
for _, keyID := range r.KeyIDs {
if _, ok := validKeys[keyID]; !ok {
return ErrInvalidMetadata{
role: metaContainingRole,
msg: fmt.Sprintf("key ID %s specified in %s without corresponding key", keyID, rootRoleName),
}
}
}
return nil
}
// NewRoot initializes a new SignedRoot with a set of keys, roles, and the consistent flag
func NewRoot(keys map[string]PublicKey, roles map[string]*RootRole, consistent bool) (*SignedRoot, error) {
signedRoot := &SignedRoot{
Signatures: make([]Signature, 0),
Signed: Root{
SignedCommon: SignedCommon{
Type: TUFTypes[CanonicalRootRole],
Version: 0,
Expires: DefaultExpires(CanonicalRootRole),
},
Keys: keys,
Roles: roles,
ConsistentSnapshot: consistent,
},
Dirty: true,
}
return signedRoot, nil
}
// BuildBaseRole returns a copy of a BaseRole using the information in this SignedRoot for the specified role name.
// Will error for invalid role name or key metadata within this SignedRoot
func (r SignedRoot) BuildBaseRole(roleName string) (BaseRole, error) {
roleData, ok := r.Signed.Roles[roleName]
if !ok {
return BaseRole{}, ErrInvalidRole{Role: roleName, Reason: "role not found in root file"}
}
// Get all public keys for the base role from TUF metadata
keyIDs := roleData.KeyIDs
pubKeys := make(map[string]PublicKey)
for _, keyID := range keyIDs {
pubKey, ok := r.Signed.Keys[keyID]
if !ok {
return BaseRole{}, ErrInvalidRole{
Role: roleName,
Reason: fmt.Sprintf("key with ID %s was not found in root metadata", keyID),
}
}
pubKeys[keyID] = pubKey
}
return BaseRole{
Name: roleName,
Keys: pubKeys,
Threshold: roleData.Threshold,
}, nil
}
// ToSigned partially serializes a SignedRoot for further signing
func (r SignedRoot) ToSigned() (*Signed, error) {
s, err := defaultSerializer.MarshalCanonical(r.Signed)
if err != nil {
return nil, err
}
// cast into a json.RawMessage
signed := json.RawMessage{}
err = signed.UnmarshalJSON(s)
if err != nil {
return nil, err
}
sigs := make([]Signature, len(r.Signatures))
copy(sigs, r.Signatures)
return &Signed{
Signatures: sigs,
Signed: &signed,
}, nil
}
// MarshalJSON returns the serialized form of SignedRoot as bytes
func (r SignedRoot) MarshalJSON() ([]byte, error) {
signed, err := r.ToSigned()
if err != nil {
return nil, err
}
return defaultSerializer.Marshal(signed)
}
// RootFromSigned fully unpacks a Signed object into a SignedRoot and ensures
// that it is a valid SignedRoot
func RootFromSigned(s *Signed) (*SignedRoot, error) {
r := Root{}
if s.Signed == nil {
return nil, ErrInvalidMetadata{
role: CanonicalRootRole,
msg: "root file contained an empty payload",
}
}
if err := defaultSerializer.Unmarshal(*s.Signed, &r); err != nil {
return nil, err
}
if err := isValidRootStructure(r); err != nil {
return nil, err
}
sigs := make([]Signature, len(s.Signatures))
copy(sigs, s.Signatures)
return &SignedRoot{
Signatures: sigs,
Signed: r,
}, nil
}