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Is it possible to send S/MIME digitally signed email with Mozilla Thunderbird using qualified digital signing smart card? How?

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up vote 2 down vote accepted

Yes, if your card reader has a compatible PKCS#11 module.

On Thunderbird, go to Tools → Account Settings, and under your mail account select Security. Click Security Devices and you will see a list all loaded modules and devices. Click Load and select the PKCS#11 module file for your card reader. (On Windows, it's a .dll file; on Linux, .so.)

  • The same window can be reached through Tools → Options → Advanced → Certificates → Security Devices.

  • The location of PKCS#11 modules is not standardized (although there are attempts to do so), so you may need to do some searching. (On Windows, two likely locations are the card reader software directory, and %SystemRoot%\System32.) CAcert has a list of common locations. You could also use the "auto-detect library" capability in TrueCrypt or FreeOTFE, then copy the resulting path into Thunderbird.

Close Security Devices and click View Certificates, and you should see certificates contained in the smartcard. Close the window and use the two Select... buttons to choose encryption and signing certificate(s).

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