Mimic the Apahe SHA-1 password creation process

I need to mimic within ASP.net the process in which Apache webservers create an SHA-1 password.

I thought it possible just to SHA-1 encrypt the password and then base-64 encode the resulting string

However this does not create the correct result.

I've read that Apache creates an sha1 digest password which is in binary format with only 20 characters.

Is it possible to create this 20 character digest password from within ASP.net?

Thanks for your help. 

 
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