Send push information to trust code out-of-band

The trust code used to parse the console output of `docker push` to
extract the digest, tag, and size information and determine what to
sign. This is fragile and might give an attacker control over what gets
signed if the attacker can find a way to influence what gets printed as
part of the push output.

This commit sends the push metadata out-of-band. It introduces an `Aux`
field in JSONMessage that can carry application-specific data alongside
progress updates. Instead of parsing formatted output, the client looks
in this field to get the digest, size, and tag from the push.

Signed-off-by: Aaron Lehmann <aaron.lehmann@docker.com>
This commit is contained in:
Aaron Lehmann 2015-12-21 15:02:44 -08:00
parent 486bca6d94
commit 1fe4441875
5 changed files with 36 additions and 7 deletions

View file

@ -102,6 +102,8 @@ type JSONMessage struct {
TimeNano int64 `json:"timeNano,omitempty"`
Error *JSONError `json:"errorDetail,omitempty"`
ErrorMessage string `json:"error,omitempty"` //deprecated
// Aux contains out-of-band data, such as digests for push signing.
Aux *json.RawMessage `json:"aux,omitempty"`
}
// Display displays the JSONMessage to `out`. `isTerminal` describes if `out`
@ -148,7 +150,7 @@ func (jm *JSONMessage) Display(out io.Writer, isTerminal bool) error {
// DisplayJSONMessagesStream displays a json message stream from `in` to `out`, `isTerminal`
// describes if `out` is a terminal. If this is the case, it will print `\n` at the end of
// each line and move the cursor while displaying.
func DisplayJSONMessagesStream(in io.Reader, out io.Writer, terminalFd uintptr, isTerminal bool) error {
func DisplayJSONMessagesStream(in io.Reader, out io.Writer, terminalFd uintptr, isTerminal bool, auxCallback func(*json.RawMessage)) error {
var (
dec = json.NewDecoder(in)
ids = make(map[string]int)
@ -163,6 +165,13 @@ func DisplayJSONMessagesStream(in io.Reader, out io.Writer, terminalFd uintptr,
return err
}
if jm.Aux != nil {
if auxCallback != nil {
auxCallback(jm.Aux)
}
continue
}
if jm.Progress != nil {
jm.Progress.terminalFd = terminalFd
}