Tag: Apple Macintosh

Basics: Name Constraints

Name constraints are part of the X.509 standard and are described in RFC 5280 . They are a tool that can be used as part of qualified subordination to control the scope of a certification authority certificate in a fine-grained manner.

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Microsoft Outlook: Signed e-mail messages are rejected by the receiving mail server with error message "Invalid S/MIME encrypted message."

Assume the following scenario:

  • A user sends an e-mail message signed with Secure/Multipurpose Internet Mail Extensions (S/MIME).
  • The sender uses Microsoft Outlook for Macintosh.
  • The receiving mail server rejects the message and sends back a Non-Delivery Report (NDR):
550 5.6.0 M2MCVT.StorageError.Exception: ConversionFailedException - , Content conversion: Invalid S/MIME encrypted message.; storage error in content conversion.

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Microsoft Outlook: Signed e-mail messages appear invalid with error message "No certificate was found to verify the signature of this message."

Assume the following scenario

  • A user receives an e-mail message signed with Secure/Multipurpose Internet Mail Extensions (S/MIME).
  • The user (the recipient) uses Microsoft Outlook for Windows.
  • The sender uses Microsoft Outlook for Macintosh.
  • The certificate used to sign the message is valid.
  • The e-mail signature is displayed as invalid. Inspection of the signature reveals that no details about the signing certificate can be displayed.
Fehler: Es wurde kein Zertifikat zum Überprüfen der Signatur dieser Nachricht gefunden.
Signiert von (Name des Zertifikatsbetreffs unbekannt) unter Verwendung von RSA/SHA256 um 15:44:59 19.05.2021.

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Microsoft Outlook: Emails encrypted with S/MIME cannot be opened. The error message "Internal error." appears.

Assume the following scenario:

  • A user receives an e-mail message encrypted with Secure/Multipurpose Internet Mail Extensions (S/MIME).
  • The message cannot be opened.
  • When opening the message, the following error message is displayed:
Leider besteht ein Problem beim Öffnen dieses Elements. Dies kann vorübergehend sein. Wenn dieser Fehler erneut auftritt, sollten Sie Outlook neu starten. Fehler im zugrunde liegenden Sicherheitssystem. Interner Fehler.

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Chrome and Safari limit SSL certificates to one year validity

Apple recently announced that the Safari browser will in future only accept certificates with a validity of 398 days, provided they were issued on or after September 1, 2020.

Mozilla and Google want to implement comparable behavior in their browsers. So the question is whether this change will have an impact on internal certification authorities - i.e. whether in future internal SSL certificates will also have to follow these rules, as was the case, for example, with Google's enforcement of RFC 2818 .

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