Break up FetchKeys

This commit is contained in:
Neil Alexander 2020-06-16 11:20:38 +01:00
parent 9fa7654beb
commit 2bbc43deff

View file

@ -70,7 +70,6 @@ func (s *ServerKeyAPI) StoreKeys(
return s.OurKeyRing.KeyDatabase.StoreKeys(ctx, results)
}
// nolint:gocyclo
func (s *ServerKeyAPI) FetchKeys(
_ context.Context,
requests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp,
@ -78,64 +77,24 @@ func (s *ServerKeyAPI) FetchKeys(
// Run in a background context - we don't want to stop this work just
// because the caller gives up waiting.
ctx := context.Background()
now := gomatrixserverlib.AsTimestamp(time.Now())
results := map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult{}
origRequests := map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp{}
for k, v := range requests {
origRequests[k] = v
}
now := gomatrixserverlib.AsTimestamp(time.Now())
// First, check if any of these key checks are for our own keys. If
// they are then we will satisfy them directly.
for req := range requests {
if req.ServerName == s.Cfg.Matrix.ServerName {
// We found a key request that is supposed to be for our own
// keys. Remove it from the request list so we don't hit the
// database or the fetchers for it.
delete(requests, req)
// Look up our own keys.
request := &api.QueryLocalKeysRequest{}
response := &api.QueryLocalKeysResponse{}
if err := s.QueryLocalKeys(ctx, request, response); err != nil {
return nil, err
}
// Depending on whether the key is expired or not, we'll need
// to write slightly different
if verifyKeys, ok := response.ServerKeys.VerifyKeys[req.KeyID]; ok {
// The key is current.
results[req] = gomatrixserverlib.PublicKeyLookupResult{
VerifyKey: verifyKeys,
ExpiredTS: gomatrixserverlib.PublicKeyNotExpired,
ValidUntilTS: response.ServerKeys.ValidUntilTS,
}
} else if verifyKeys, ok := response.ServerKeys.OldVerifyKeys[req.KeyID]; ok {
// The key is expired.
results[req] = gomatrixserverlib.PublicKeyLookupResult{
VerifyKey: verifyKeys.VerifyKey,
ExpiredTS: verifyKeys.ExpiredTS,
ValidUntilTS: gomatrixserverlib.PublicKeyNotValid,
}
}
}
if err := s.handleLocalKeys(ctx, requests, results); err != nil {
return nil, err
}
// Then consult our local database and see if we have the requested
// keys. These might come from a cache, depending on the database
// implementation used.
if dbResults, err := s.OurKeyRing.KeyDatabase.FetchKeys(ctx, requests); err == nil {
// We successfully got some keys. Add them to the results.
for req, res := range dbResults {
results[req] = res
// If the key is valid right now then we can also remove it
// from the request list as we don't need to fetch it again
// in that case.
if res.WasValidAt(now, true) {
delete(requests, req)
}
}
if err := s.handleDatabaseKeys(ctx, now, requests, results); err != nil {
return nil, err
}
// For any key requests that we still have outstanding, next try to
@ -146,68 +105,13 @@ func (s *ServerKeyAPI) FetchKeys(
if len(requests) == 0 {
break
}
fetcherCtx, fetcherCancel := context.WithTimeout(ctx, time.Second*30)
defer fetcherCancel()
logrus.WithFields(logrus.Fields{
"fetcher_name": fetcher.FetcherName(),
}).Infof("Fetching %d key(s)", len(requests))
if fetcherResults, err := fetcher.FetchKeys(fetcherCtx, requests); err == nil {
// Build a map of the results that we want to commit to the
// database. We do this in a separate map because otherwise we
// might end up trying to rewrite database entries.
storeResults := map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult{}
// Now let's look at the results that we got from this fetcher.
for req, res := range fetcherResults {
if prev, ok := results[req]; ok {
// We've already got a previous entry for this request
// so let's see if the newly retrieved one contains a more
// up-to-date validity period.
if res.ValidUntilTS > prev.ValidUntilTS {
// This key is newer than the one we had so let's store
// it in the database.
if req.ServerName != s.Cfg.Matrix.ServerName {
storeResults[req] = res
}
}
} else {
// We didn't already have a previous entry for this request
// so store it in the database anyway for now.
if req.ServerName != s.Cfg.Matrix.ServerName {
storeResults[req] = res
}
}
// Update the results map with this new result. If nothing
// else, we can try verifying against this key.
results[req] = res
// If the key is valid right now then we can remove it from the
// request list as we won't need to re-fetch it.
if res.WasValidAt(now, true) {
delete(requests, req)
}
}
// Store the keys from our store map.
if err = s.OurKeyRing.KeyDatabase.StoreKeys(ctx, storeResults); err != nil {
logrus.WithError(err).WithFields(logrus.Fields{
"fetcher_name": fetcher.FetcherName(),
"database_name": s.OurKeyRing.KeyDatabase.FetcherName(),
}).Errorf("Failed to store keys in the database")
return nil, fmt.Errorf("server key API failed to store retrieved keys: %w", err)
}
if len(storeResults) > 0 {
logrus.WithFields(logrus.Fields{
"fetcher_name": fetcher.FetcherName(),
}).Infof("Updated %d of %d key(s) in database", len(storeResults), len(results))
}
} else {
// Ask the fetcher to look up our keys.
if err := s.handleFetcherKeys(ctx, now, fetcher, requests, results); err != nil {
logrus.WithError(err).WithFields(logrus.Fields{
"fetcher_name": fetcher.FetcherName(),
}).Errorf("Failed to retrieve %d key(s)", len(requests))
continue
}
}
@ -233,3 +137,153 @@ func (s *ServerKeyAPI) FetchKeys(
func (s *ServerKeyAPI) FetcherName() string {
return fmt.Sprintf("ServerKeyAPI (wrapping %q)", s.OurKeyRing.KeyDatabase.FetcherName())
}
// handleLocalKeys handles cases where the key request contains
// a request for our own server keys.
func (s *ServerKeyAPI) handleLocalKeys(
ctx context.Context,
requests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp,
results map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult,
) error {
for req := range requests {
if req.ServerName == s.Cfg.Matrix.ServerName {
// We found a key request that is supposed to be for our own
// keys. Remove it from the request list so we don't hit the
// database or the fetchers for it.
delete(requests, req)
// Look up our own keys.
request := &api.QueryLocalKeysRequest{}
response := &api.QueryLocalKeysResponse{}
if err := s.QueryLocalKeys(ctx, request, response); err != nil {
return err
}
// Depending on whether the key is expired or not, we'll need
// to write slightly different
if verifyKeys, ok := response.ServerKeys.VerifyKeys[req.KeyID]; ok {
// The key is current.
results[req] = gomatrixserverlib.PublicKeyLookupResult{
VerifyKey: verifyKeys,
ExpiredTS: gomatrixserverlib.PublicKeyNotExpired,
ValidUntilTS: response.ServerKeys.ValidUntilTS,
}
} else if verifyKeys, ok := response.ServerKeys.OldVerifyKeys[req.KeyID]; ok {
// The key is expired.
results[req] = gomatrixserverlib.PublicKeyLookupResult{
VerifyKey: verifyKeys.VerifyKey,
ExpiredTS: verifyKeys.ExpiredTS,
ValidUntilTS: gomatrixserverlib.PublicKeyNotValid,
}
}
}
}
return nil
}
// handleDatabaseKeys handles cases where the key requests can be
// satisfied from our local database/cache.
func (s *ServerKeyAPI) handleDatabaseKeys(
ctx context.Context,
now gomatrixserverlib.Timestamp,
requests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp,
results map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult,
) error {
// Ask the database/cache for the keys.
dbResults, err := s.OurKeyRing.KeyDatabase.FetchKeys(ctx, requests)
if err != nil {
return err
}
// We successfully got some keys. Add them to the results.
for req, res := range dbResults {
results[req] = res
// If the key is valid right now then we can also remove it
// from the request list as we don't need to fetch it again
// in that case.
if res.WasValidAt(now, true) {
delete(requests, req)
}
}
return nil
}
// handleDatabaseKeys handles cases where a fetcher can satisfy
// the remaining requests.
func (s *ServerKeyAPI) handleFetcherKeys(
ctx context.Context,
now gomatrixserverlib.Timestamp,
fetcher gomatrixserverlib.KeyFetcher,
requests map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.Timestamp,
results map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult,
) error {
logrus.WithFields(logrus.Fields{
"fetcher_name": fetcher.FetcherName(),
}).Infof("Fetching %d key(s)", len(requests))
// Create a context that limits our requests to 30 seconds.
fetcherCtx, fetcherCancel := context.WithTimeout(ctx, time.Second*30)
defer fetcherCancel()
// Try to fetch the keys.
fetcherResults, err := fetcher.FetchKeys(fetcherCtx, requests)
if err != nil {
return err
}
// Build a map of the results that we want to commit to the
// database. We do this in a separate map because otherwise we
// might end up trying to rewrite database entries.
storeResults := map[gomatrixserverlib.PublicKeyLookupRequest]gomatrixserverlib.PublicKeyLookupResult{}
// Now let's look at the results that we got from this fetcher.
for req, res := range fetcherResults {
if prev, ok := results[req]; ok {
// We've already got a previous entry for this request
// so let's see if the newly retrieved one contains a more
// up-to-date validity period.
if res.ValidUntilTS > prev.ValidUntilTS {
// This key is newer than the one we had so let's store
// it in the database.
if req.ServerName != s.Cfg.Matrix.ServerName {
storeResults[req] = res
}
}
} else {
// We didn't already have a previous entry for this request
// so store it in the database anyway for now.
if req.ServerName != s.Cfg.Matrix.ServerName {
storeResults[req] = res
}
}
// Update the results map with this new result. If nothing
// else, we can try verifying against this key.
results[req] = res
// If the key is valid right now then we can remove it from the
// request list as we won't need to re-fetch it.
if res.WasValidAt(now, true) {
delete(requests, req)
}
}
// Store the keys from our store map.
if err = s.OurKeyRing.KeyDatabase.StoreKeys(ctx, storeResults); err != nil {
logrus.WithError(err).WithFields(logrus.Fields{
"fetcher_name": fetcher.FetcherName(),
"database_name": s.OurKeyRing.KeyDatabase.FetcherName(),
}).Errorf("Failed to store keys in the database")
return fmt.Errorf("server key API failed to store retrieved keys: %w", err)
}
if len(storeResults) > 0 {
logrus.WithFields(logrus.Fields{
"fetcher_name": fetcher.FetcherName(),
}).Infof("Updated %d of %d key(s) in database", len(storeResults), len(results))
}
return nil
}