docs/tuf/data/timestamp.go

83 lines
1.8 KiB
Go

package data
import (
"bytes"
"time"
"github.com/jfrazelle/go/canonical/json"
)
// SignedTimestamp is a fully unpacked timestamp.json
type SignedTimestamp struct {
Signatures []Signature
Signed Timestamp
Dirty bool
}
// Timestamp is the Signed component of a timestamp.json
type Timestamp struct {
Type string `json:"_type"`
Version int `json:"version"`
Expires time.Time `json:"expires"`
Meta Files `json:"meta"`
}
// NewTimestamp initializes a timestamp with an existing snapshot
func NewTimestamp(snapshot *Signed) (*SignedTimestamp, error) {
snapshotJSON, err := json.Marshal(snapshot)
if err != nil {
return nil, err
}
snapshotMeta, err := NewFileMeta(bytes.NewReader(snapshotJSON), "sha256")
if err != nil {
return nil, err
}
return &SignedTimestamp{
Signatures: make([]Signature, 0),
Signed: Timestamp{
Type: TUFTypes["timestamp"],
Version: 0,
Expires: DefaultExpires("timestamp"),
Meta: Files{
ValidRoles["snapshot"]: snapshotMeta,
},
},
}, nil
}
// ToSigned partially serializes a SignedTimestamp such that it can
// be signed
func (ts SignedTimestamp) ToSigned() (*Signed, error) {
s, err := json.MarshalCanonical(ts.Signed)
if err != nil {
return nil, err
}
signed := json.RawMessage{}
err = signed.UnmarshalJSON(s)
if err != nil {
return nil, err
}
sigs := make([]Signature, len(ts.Signatures))
copy(sigs, ts.Signatures)
return &Signed{
Signatures: sigs,
Signed: signed,
}, nil
}
// TimestampFromSigned parsed a Signed object into a fully unpacked
// SignedTimestamp
func TimestampFromSigned(s *Signed) (*SignedTimestamp, error) {
ts := Timestamp{}
err := json.Unmarshal(s.Signed, &ts)
if err != nil {
return nil, err
}
sigs := make([]Signature, len(s.Signatures))
copy(sigs, s.Signatures)
return &SignedTimestamp{
Signatures: sigs,
Signed: ts,
}, nil
}