Factory-resetting a kdf-enabled card cannot restore its PINs to default values on a J3R180 card

[wreps8Owt]

Using the factory-reset command of GnuPG on a J3R180 card without kdf enabled does restore its PINs to default values, but factory-resetting a kdf-enabled card cannot. It seems that all parameters return to default, but PINs (especially the admin PIN) does not work. The only way to "restore" it is to reinstall the CAP file.

[wreps8Owt]

Besides, smartpgp-cli seems unable to pass the PIN authentication against a kdf-enabled card.

[wreps8Owt]

This issue is opened when my account remained flagged, so you might not be noticed then.

[af-anssi]

Using the factory-reset command of GnuPG on a card without kdf enabled does restore its PINs to default values, but factory-resetting a kdf-enabled card cannot. It seems that all parameters return to default, but PINs (especially the admin PIN) does not work. The only way to "restore" it is to reinstall the CAP file.

Which version of the applet are you using?

KDF parameters are actually reset within the applet during a factory reset:
https://github.com/ANSSI-FR/SmartPGP/blob/master/src/fr/anssi/smartpgp/Persistent.java#L226

After a factory reset did you remove the card from the reader and then reinsert it? I suspect a caching mechanism of GnuPG to not deal correctly with the reset of the KDF parameters.

[af-anssi]

Besides, smartpgp-cli seems unable to pass the PIN authentication against a kdf-enabled card.

Yes KDF-enabled PIN is not supported in smartpgp-cli.

[wreps8Owt]

> Using the factory-reset command of GnuPG on a card without kdf enabled does restore its PINs to default values, but factory-resetting a kdf-enabled card cannot. It seems that all parameters return to default, but PINs (especially the admin PIN) does not work. The only way to "restore" it is to reinstall the CAP file. Which version of the applet are you using?

The current master, built against jc304.

KDF parameters are actually reset within the applet during a factory reset: https://github.com/ANSSI-FR/SmartPGP/blob/master/src/fr/anssi/smartpgp/Persistent.java#L226 After a factory reset did you remove the card from the reader and then reinsert it? I suspect a caching mechanism of GnuPG to not deal correctly with the reset of the KDF parameters.

Yes. After a factory reset of a card with KDF enabled, reinserting, killing gpg-agent, or even restarting pcscd, cannot make default admin PIN work. In Persistent() of Persistent.java, `key_derivation_function_length` is set to 0, and (key_derivation_function_length > 0) is judged in many place , but during reset, it seems to be "reset" to Constants.KEY_DERIVATION_FUNCTION_DEFAULT.length, which may be 3. Is this okay?

[af-anssi]

Yes. After a factory reset of a card with KDF enabled, reinserting, killing gpg-agent, or even restarting pcscd, cannot make default admin PIN work. In Persistent() of Persistent.java, key_derivation_function_length is set to 0, and (key_derivation_function_length > 0) is judged in many place , but during reset, it seems to be "reset" to Constants.KEY_DERIVATION_FUNCTION_DEFAULT.length, which may be 3. Is this okay?

When the Peristent instance is created the key_derivation_function_length is set to 0 https://github.com/ANSSI-FR/SmartPGP/blob/master/src/fr/anssi/smartpgp/Persistent.java#L131, but at the end of the constructor the reset function is called https://github.com/ANSSI-FR/SmartPGP/blob/master/src/fr/anssi/smartpgp/Persistent.java#L137 so the key_derivation_function_length is reset at https://github.com/ANSSI-FR/SmartPGP/blob/master/src/fr/anssi/smartpgp/Persistent.java#L233 to its default value https://github.com/ANSSI-FR/SmartPGP/blob/master/src/fr/anssi/smartpgp/Constants.java#L32.

[af-anssi]

If you agree with my explanations could you close this issue?

[wreps8Owt]

If you agree with my explanations could you close this issue?

Why? The issue remains persist. Your explanations cannot explain the issue.

[wreps8Owt]

It just mean that my guess is not the reason of this issue.

[af-anssi]

SmartPGP is implemented such that its internal status after installation is strictly the same as after a factory reset with only two exceptions: the SM certificate (that you do not use) and the use (or not) of the transaction mechanism (which is not available during first installation).
The constructor of the Persistent instance, which holds all data in flash memory (that survives card unplug/power off), ends with a call to its reset function which is also the one called during a factory reset: https://github.com/ANSSI-FR/SmartPGP/blob/master/src/fr/anssi/smartpgp/SmartPGPApplet.java#L1492.

[af-anssi]

After a factory reset could you remove (after a backup if necessary) your .gnupg directory in addition to kill any daemons and finally reinsert your card?

[wreps8Owt]

After a factory reset could you remove (or backup it if necessary) your `.gnupg` directory in addition to kill any daemons and finally reinsert your card?

Sure, and the issue persists. Even smartpgp-cli cannot pass the authentication with default admin pinl, if only the card had kdf setup, and then factory reset.

[af-anssi]

How did you setup/enable KDF?

[wreps8Owt]

How did you setup/enable KDF?

Use smartpgp-cli .