mirror of
https://github.com/mjl-/mox.git
synced 2024-12-27 00:43:48 +03:00
72ac1fde29
- prometheus is now behind an interface, they aren't dependencies for the reusable components anymore. - some dependencies have been inverted: instead of packages importing a main package to get configuration, the main package now sets configuration in these packages. that means fewer internals are pulled in. - some functions now have new parameters for values that were retrieved from package "mox-".
52 lines
1.7 KiB
Go
52 lines
1.7 KiB
Go
package message
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"strings"
|
|
|
|
"github.com/mjl-/mox/smtp"
|
|
)
|
|
|
|
var errBadMessageID = errors.New("not a message-id")
|
|
|
|
// MessageIDCanonical parses the Message-ID, returning a canonical value that is
|
|
// lower-cased, without <>, and no unneeded quoting. For matching in threading,
|
|
// with References/In-Reply-To. If the message-id is invalid (e.g. no <>), an error
|
|
// is returned. If the message-id could not be parsed as address (localpart "@"
|
|
// domain), the raw value and the bool return parameter true is returned. It is
|
|
// quite common that message-id's don't adhere to the localpart @ domain
|
|
// syntax.
|
|
func MessageIDCanonical(s string) (string, bool, error) {
|
|
// ../rfc/5322:1383
|
|
|
|
s = strings.TrimSpace(s)
|
|
if !strings.HasPrefix(s, "<") {
|
|
return "", false, fmt.Errorf("%w: missing <", errBadMessageID)
|
|
}
|
|
s = s[1:]
|
|
// Seen in practice: Message-ID: <valid@valid.example> (added by postmaster@some.example)
|
|
// Doesn't seem valid, but we allow it.
|
|
s, rem, have := strings.Cut(s, ">")
|
|
if !have || (rem != "" && (Pedantic || !strings.HasPrefix(rem, " "))) {
|
|
return "", false, fmt.Errorf("%w: missing >", errBadMessageID)
|
|
}
|
|
// We canonicalize the Message-ID: lower-case, no unneeded quoting.
|
|
s = strings.ToLower(s)
|
|
if s == "" {
|
|
return "", false, fmt.Errorf("%w: empty message-id", errBadMessageID)
|
|
}
|
|
addr, err := smtp.ParseAddress(s)
|
|
if err != nil {
|
|
// Common reasons for not being an address:
|
|
// 1. underscore in hostname.
|
|
// 2. ip literal instead of domain.
|
|
// 3. two @'s, perhaps intended as time-separator
|
|
// 4. no @'s, so no domain/host
|
|
return s, true, nil
|
|
}
|
|
// We preserve the unicode-ness of domain.
|
|
t := strings.Split(s, "@")
|
|
s = addr.Localpart.String() + "@" + t[len(t)-1]
|
|
return s, false, nil
|
|
}
|