Bagajjal/fix minor issues

[bagajjal]

1. Remove unnecessary references to ssh-pkcs11.c
2. fix warnings
3. Create the duplicate token used for create process(ssh-pkcs11-helper.exe)
4. Delete and overwrite the ssh-pkcs11 keys when ssh-add.exe is rerun again.

[yan4321]

@bagajjal , I think you might have missed my comment here.

Failing to add a provider if it already exists is done intentionally as this is the upstream behavior of openssh/openssh-portable. It also makes sense for the user to explicitly remove a provider that already exists before re-adding.

[yan4321]

@bagajjal , Exposing the token itself as a global variable is a bit riskier than exposing the client's pid.

[bagajjal]

@bagajjal , Exposing the token itself as a global variable is a bit riskier than exposing the client's pid.

We already do this in multiple places. I don't see why it's riskier.

openssh-portable/contrib/win32/win32compat/spawn-ext.c

Line 11 in 3a33ea8

extern HANDLE password_auth_token;

[bagajjal]

@bagajjal , I think you might have missed my comment here.

Failing to add a provider if it already exists is done intentionally as this is the upstream behavior of openssh/openssh-portable. It also makes sense for the user to explicitly remove a provider that already exists before re-adding.

It was an intentional change. To me it doesn't make sense to fail it. If we fail, the error message is not clear as to why it's failing. I don't see failure message in the upstream code.
Even if it's a deviation from the upstream, I would like to do whatever it's better for customers.