package identity
import (
"crypto/rand"
"crypto/sha256"
"encoding/json"
"fmt"
"strings"
"time"
"github.com/pkg/errors"
"github.com/MichaelMure/git-bug/entity"
"github.com/MichaelMure/git-bug/repository"
"github.com/MichaelMure/git-bug/util/lamport"
"github.com/MichaelMure/git-bug/util/text"
)
// 1: original format
// 2: Identity Ids are generated from the first version serialized data instead of from the first git commit
const formatVersion = 2
// TODO ^^
// version is a complete set of information about an Identity at a point in time.
type version struct {
name string
email string // as defined in git or from a bridge when importing the identity
login string // from a bridge when importing the identity
avatarURL string
// The lamport times of the other entities at which this version become effective
times map[string]lamport.Time
unixTime int64
// The set of keys valid at that time, from this version onward, until they get removed
// in a new version. This allow to have multiple key for the same identity (e.g. one per
// device) as well as revoke key.
keys []*Key
// mandatory random bytes to ensure a better randomness of the data of the first
// version of a bug, used to later generate the ID
// len(Nonce) should be > 20 and < 64 bytes
// It has no functional purpose and should be ignored.
// TODO: optional?
nonce []byte
// A set of arbitrary key/value to store metadata about a version or about an Identity in general.
metadata map[string]string
// Not serialized. Store the version's id in memory.
id entity.Id
// Not serialized
commitHash repository.Hash
}
func newVersion(repo repository.RepoClock, name string, email string, login string, avatarURL string, keys []*Key) (*version, error) {
clocks, err := repo.AllClocks()
if err != nil {
return nil, err
}
times := make(map[string]lamport.Time)
for name, clock := range clocks {
times[name] = clock.Time()
}
return &version{
id: entity.UnsetId,
name: name,
email: email,
login: login,
avatarURL: avatarURL,
times: times,
unixTime: time.Now().Unix(),
keys: keys,
nonce: makeNonce(20),
}, nil
}
type versionJSON struct {
// Additional field to version the data
FormatVersion uint `json:"version"`
Times map[string]lamport.Time `json:"times"`
UnixTime int64 `json:"unix_time"`
Name string `json:"name,omitempty"`
Email string `json:"email,omitempty"`
Login string `json:"login,omitempty"`
AvatarUrl string `json:"avatar_url,omitempty"`
Keys []*Key `json:"pub_keys,omitempty"`
Nonce []byte `json:"nonce"`
Metadata map[string]string `json:"metadata,omitempty"`
}
// Id return the identifier of the version
func (v *version) Id() entity.Id {
if v.id == "" {
// something went really wrong
panic("version's id not set")
}
if v.id == entity.UnsetId {
// This means we are trying to get the version's Id *before* it has been stored.
// As the Id is computed based on the actual bytes written on the disk, we are going to predict
// those and then get the Id. This is safe as it will be the exact same code writing on disk later.
data, err := json.Marshal(v)
if err != nil {
panic(err)
}
v.id = deriveId(data)
}
return v.id
}
func deriveId(data []byte) entity.Id {
sum := sha256.Sum256(data)
return entity.Id(fmt.Sprintf("%x", sum))
}
// Make a deep copy
func (v *version) Clone() *version {
// copy direct fields
clone := *v
clone.times = make(map[string]lamport.Time)
for name, t := range v.times {
clone.times[name] = t
}
clone.keys = make([]*Key, len(v.keys))
for i, key := range v.keys {
clone.keys[i] = key.Clone()
}
clone.nonce = make([]byte, len(v.nonce))
copy(clone.nonce, v.nonce)
// not copying metadata
return &clone
}
func (v *version) MarshalJSON() ([]byte, error) {
return json.Marshal(versionJSON{
FormatVersion: formatVersion,
Times: v.times,
UnixTime: v.unixTime,
Name: v.name,
Email: v.email,
Login: v.login,
AvatarUrl: v.avatarURL,
Keys: v.keys,
Nonce: v.nonce,
Metadata: v.metadata,
})
}
func (v *version) UnmarshalJSON(data []byte) error {
var aux versionJSON
if err := json.Unmarshal(data, &aux); err != nil {
return err
}
if aux.FormatVersion < formatVersion {
return entity.NewErrOldFormatVersion(aux.FormatVersion)
}
if aux.FormatVersion > formatVersion {
return entity.NewErrNewFormatVersion(aux.FormatVersion)
}
v.id = deriveId(data)
v.times = aux.Times
v.unixTime = aux.UnixTime
v.name = aux.Name
v.email = aux.Email
v.login = aux.Login
v.avatarURL = aux.AvatarUrl
v.keys = aux.Keys
v.nonce = aux.Nonce
v.metadata = aux.Metadata
return nil
}
func (v *version) Validate() error {
// time must be set after a commit
if v.commitHash != "" && v.unixTime == 0 {
return fmt.Errorf("unix time not set")
}
if text.Empty(v.name) && text.Empty(v.login) {
return fmt.Errorf("either name or login should be set")
}
if strings.Contains(v.name, "\n") {
return fmt.Errorf("name should be a single line")
}
if !text.Safe(v.name) {
return fmt.Errorf("name is not fully printable")
}
if strings.Contains(v.login, "\n") {
return fmt.Errorf("login should be a single line")
}
if !text.Safe(v.login) {
return fmt.Errorf("login is not fully printable")
}
if strings.Contains(v.email, "\n") {
return fmt.Errorf("email should be a single line")
}
if !text.Safe(v.email) {
return fmt.Errorf("email is not fully printable")
}
if v.avatarURL != "" && !text.ValidUrl(v.avatarURL) {
return fmt.Errorf("avatarUrl is not a valid URL")
}
if len(v.nonce) > 64 {
return fmt.Errorf("nonce is too big")
}
if len(v.nonce) < 20 {
return fmt.Errorf("nonce is too small")
}
for _, k := range v.keys {
if err := k.Validate(); err != nil {
return errors.Wrap(err, "invalid key")
}
}
return nil
}
// Write will serialize and store the version as a git blob and return
// its hash
func (v *version) Write(repo repository.Repo) (repository.Hash, error) {
// make sure we don't write invalid data
err := v.Validate()
if err != nil {
return "", errors.Wrap(err, "validation error")
}
data, err := json.Marshal(v)
if err != nil {
return "", err
}
hash, err := repo.StoreData(data)
if err != nil {
return "", err
}
// make sure we set the Id when writing in the repo
v.id = deriveId(data)
return hash, nil
}
func makeNonce(len int) []byte {
result := make([]byte, len)
_, err := rand.Read(result)
if err != nil {
panic(err)
}
return result
}
// SetMetadata store arbitrary metadata about a version or an Identity in general
// If the version has been commit to git already, it won't be overwritten.
// Beware: changing the metadata on a version will change it's ID
func (v *version) SetMetadata(key string, value string) {
if v.metadata == nil {
v.metadata = make(map[string]string)
}
v.metadata[key] = value
}
// GetMetadata retrieve arbitrary metadata about the version
func (v *version) GetMetadata(key string) (string, bool) {
val, ok := v.metadata[key]
return val, ok
}
// AllMetadata return all metadata for this version
func (v *version) AllMetadata() map[string]string {
return v.metadata
}
